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ReleaseNotes

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    ReleaseNotes 1.50 MiB
    This document summarizes new features and bugfixes in each stable
    release of Tor. If you want to see more detailed descriptions of the
    changes in each development snapshot, see the ChangeLog file.
    
    Changes in version 0.4.8.17 - 2025-06-30
      This is a minor providing a series of minor features especially in the realm
      of TLS. It also brings a new set of recommended and required sub protocols.
      And finally, few minor bugfixes, nothing major. As always, we strongly
      recommend you upgrade as soon as possible.
    
      o Minor features (security, TLS):
        - When we are running with OpenSSL 3.5.0 or later, support using the
          ML-KEM768 for post-quantum key agreement. Closes ticket 41041.
    
      o Minor feature (client, TLS):
        - Set the TLS 1.3 cipher list instead of falling back on the
          default value.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on June 30, 2025.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2025/06/30.
    
      o Minor features (hsdesc POW):
        - Tolerate multiple PoW schemes in onion service descriptors, for
          future extensibility. Implements torspec ticket 272.
    
      o Minor features (performance TLS):
        - When running with with OpenSSL 3.0.0 or later, support using
          X25519 for TLS key agreement. (This should slightly improve
          performance for TLS session establishment.)
    
      o Minor features (portability):
        - Fix warnings when compiling with GCC 15. Closes ticket 41079.
    
      o Minor features (recommended protocols):
        - Directory authorities now vote to recommend that clients support
          certain protocols beyond those that are required. These include
          improved support for connecting to relays on IPv6, NtorV3, and
          congestion control. Part of ticket 40836.
    
      o Minor features (required protocols):
        - Directory authorities now vote to require clients to support the
          authenticated SENDME feature, which was introduced in
          0.4.1.1-alpha. Part of ticket 40836.
        - Directory authorities now vote to require relays to support
          certain protocols, all of which have been implemented since
          0.4.7.4-alpha or earlier. These include improved support for
          connecting to relays on IPv6, NtorV3, running as a rate-limited
          introduction point, authenticated SENDMEs, and congestion control.
          Part of ticket 40836.
    
      o Minor bugfix (conflux):
        - Avoid a non fatal assert when describing a conflux circuit on the
          control port after being prepped to be freed. Fixes bug 41037;
          bugfix on 0.4.8.15.
    
      o Minor bugfixes (circuit handling):
        - Prevent circuit_mark_for_close() from being called twice on the
          same circuit. Fixes bug 40951; bugfix on 0.4.8.16-dev.
    
      o Minor bugfixes (compiler warnings):
        - Make sure the two bitfields in the half-closed edge struct are
          unsigned, as we're using them for boolean values and assign 1 to
          them. Fixes bug 40911; bugfix on 0.4.7.2-alpha.
    
      o Minor bugfixes (threads, memory):
        - Improvements in cleanup of resources used by threads. Fixes bug
          40991; bugfix on 0.4.8.13-dev.
        - Rework start and exit of worker threads.
    
    
    Changes in version 0.4.8.16 - 2025-03-24
      This is quick second release since 0.4.8.15 due to a typo in a directory
      authority rule file. This only affects directory authorities. Regardless,
      upgrading to latest stable is always desired.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2025/03/24.
    
      o Minor bugfix (dirauth):
        - Fix typo in flag assignment approved-routers file. Fixes bug
          41035; bugfix on 0.4.8.15
    
    
    Changes in version 0.4.8.15 - 2025-03-20
      This is a minor release fixing a sandbox issue for bandwidth authority and a
      conflux issue on the control port. It also has a client fix about relay flag
      usage. We strongly recommend to update as soon as possible as usual.
    
      o Minor feature (testing, CI):
        - Use a fixed version of chutney (be881a1e) instead of its current
          HEAD. This version should also be preferred when testing locally.
    
      o Minor features (continuous integration):
        - Upgrade CI runners to use Debian Bookworm instead of Bullseye.
          Closes ticket 41029.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on March 20, 2025.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2025/03/20.
    
      o Minor bugfixes (control port):
        - Correctly report conflux pair information to controller fields
          Fixes bug 40872; bugfix on 0.4.8.1-alpha
    
      o Minor bugfixes (relay flag usage):
        - Fix client usage of the MiddleOnly flag so that MiddleOnly relays
          are not used as HS IP or RP by clients or services. Additionally,
          give dirauths the ability to remove specific flags, as an
          alternative to MiddleOnly. Fixes bug 41023; bugfix on 0.4.7.2-alpha
    
      o Minor bugfixes (sandbox, bwauth):
        - Fix sandbox to work for bandwidth authority. Fixes bug 40933;
          bugfix on 0.2.2.1-alpha
    
    
    Changes in version 0.4.8.14 - 2025-02-05
      Minor release fixing a major bug affecting onion service directory cache,
      also known as HSDir. Furthermore, the fallbackdir list had more than 25% of
      its entries unreachable or gone from the consensus. As usual, we strongly
      recommend to update to this version as soon as possible.
    
      o Major bugfixes (onion service directory cache):
        - When the OOM killer kicks in, cleanup the descriptor cache of an
          HSDir by looking at the lowest downloaded count instead of time in
          cache. Fixes bug 40996; bugfix on 0.3.5.1-alpha.
    
      o Minor feature (testing):
        - test-network now unconditionally includes IPv6 instead of trying
          to detect IPv6 support.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on February 05, 2025.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2025/02/05.
    
      o Minor bugfixes (memory):
        - Fix a pointer free that wasn't set to NULL afterwards which could
          be reused by calling back in the free all function. Fixes bug
          40989; bugfix on 0.4.8.13.
    
    
    Changes in version 0.4.8.13 - 2024-10-24
      This is minor release fixing an important client circuit building (Conflux
      related) bug which lead to performance degradation and extra load on the
      network. Some minor memory leaks fixes as well as an important minor feature
      for pluggable transports. We strongly recommend to update as soon as possible
      for clients in order to neutralize this conflux bug.
    
      o Major bugfixes (circuit building):
        - Conflux circuit building was ignoring the "predicted ports"
          feature, which aims to make Tor stop building circuits if there
          have been no user requests lately. This bug led to every idle Tor
          on the network building and discarding circuits every 30 seconds,
          which added overall load to the network, used bandwidth and
          battery from clients that weren't actively using their Tor, and
          kept sockets open on guards which added connection padding
          essentially forever. Fixes bug 40981; bugfix on 0.4.8.1-alpha;
    
      o Minor feature (bridges, pluggable transport):
        - Add STATUS TYPE=version handler for Pluggable Transport. This
          allows us to gather version statistics on Pluggable Transport
          usage from bridge servers on our metrics portal. Closes
          ticket 11101.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on October 24, 2024.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2024/10/24.
    
      o Minor bugfixes (memleak, authority):
        - Fix a small memleak when computing a new consensus. This only
          affects directory authorities. Fixes bug 40966; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (memory):
        - Fix memory leaks of the CPU worker code during shutdown. Fixes bug
          833; bugfix on 0.3.5.1-alpha.
    
    
    Changes in version 0.4.8.12 - 2024-06-06
      This is a minor release with couple bugfixes affecting conflux and logging.
      We also have the return of faravahar directory authority with new keys and
      address.
    
      o Minor feature (dirauth):
        - Add back faravahar with a new address and new keys. Closes 40689.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on June 06, 2024.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2024/06/06.
    
      o Minor bugfix (circuit):
        - Remove a log_warn being triggered by a protocol violation that
          already emits a protocol warning log. Fixes bug 40932; bugfix
          on 0.4.8.1-alpha.
    
      o Minor bugfixes (conflux):
        - Avoid a potential hard assert (crash) when sending a cell on a
          Conflux set. Fixes bug 40921; bugfix on 0.4.8.1-alpha.
        - Make sure we don't process a closed circuit when packaging data.
          This lead to a non fatal BUG() spamming logs. Fixes bug 40908;
          bugfix on 0.4.8.1-alpha.
    
    
    Changes in version 0.4.8.11 - 2024-04-10
      This is a minor release mostly to upgrade the fallbackdir list.
      Directory authorities running this version will now automatically
      reject relays running the end of life 0.4.7.x version.
    
      o Minor features (directory authorities):
        - Reject 0.4.7.x series at the authority level. Closes ticket 40896.
        - New IP address and keys for tor26.
        - Allow BandwidthFiles "node_id" KeyValue without the dollar sign at
          the start of the hexdigit, in order to easier database queries
          combining Tor documents in which the relays fingerprint does not
          include it. Fixes bug 40891; bugfix on 0.4.7 (all supported
          versions of Tor).
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on April 10, 2024.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2024/04/10.
    
      o Minor bugfixes (directory authorities):
        - Add a warning when publishing a vote or signatures to another
          directory authority fails. Fixes bug 40910; bugfix on 0.2.0.3-alpha.
    
    
    Changes in version 0.4.8.10 - 2023-12-08
      This is a security release fixing a high severity bug (TROVE-2023-007)
      affecting Exit relays supporting Conflux. We strongly recommend to update as
      soon as possible.
    
      o Major bugfixes (TROVE-2023-007, exit):
        - Improper error propagation from a safety check in conflux leg
          linking led to a desynchronization of which legs were part of a
          conflux set, ultimately causing a UAF and NULL pointer dereference
          crash on Exit relays. Fixes bug 40897; bugfix on 0.4.8.1-alpha.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on December 08, 2023.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2023/12/08.
    
      o Minor bugfixes (bridges, statistics):
        - Correctly report statistics for client count over pluggable
          transports. Fixes bug 40871; bugfix on 0.4.8.4.
    
    
    Changes in version 0.4.8.9 - 2023-11-09
      This is another security release fixing a high severity bug affecting onion
      services which is tracked by TROVE-2023-006. We are also releasing a guard
      major bugfix as well. If you are an onion service operator, we strongly
      recommend to update as soon as possible.
    
      o Major bugfixes (guard usage):
        - When Tor excluded a guard due to temporary circuit restrictions,
          it considered *additional* primary guards for potential usage by
          that circuit. This could result in more than the specified number
          of guards (currently 2) being used, long-term, by the tor client.
          This could happen when a Guard was also selected as an Exit node,
          but it was exacerbated by the Conflux guard restrictions. Both
          instances have been fixed. Fixes bug 40876; bugfix
          on 0.3.0.1-alpha.
    
      o Major bugfixes (onion service, TROVE-2023-006):
        - Fix a possible hard assert on a NULL pointer when recording a
          failed rendezvous circuit on the service side for the MetricsPort.
          Fixes bug 40883; bugfix on 0.4.8.1-alpha.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on November 09, 2023.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2023/11/09.
    
    
    Changes in version 0.4.8.8 - 2023-11-03
      We are releasing today a fix for a high security issue, TROVE-2023-004, that
      is affecting relays. Also a few minor bugfixes detailed below. Please upgrade
      as soon as posssible.
    
      o Major bugfixes (TROVE-2023-004, relay):
        - Mitigate an issue when Tor compiled with OpenSSL can crash during
          handshake with a remote relay. Fixes bug 40874; bugfix
          on 0.2.7.2-alpha.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on November 03, 2023.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2023/11/03.
    
      o Minor bugfixes (directory authority):
        - Look at the network parameter "maxunmeasuredbw" with the correct
          spelling. Fixes bug 40869; bugfix on 0.4.6.1-alpha.
    
      o Minor bugfixes (vanguards addon support):
        - Count the conflux linked cell as valid when it is successfully
          processed. This will quiet a spurious warn in the vanguards addon.
          Fixes bug 40878; bugfix on 0.4.8.1-alpha.
    
    
    Changes in version 0.4.8.7 - 2023-09-25
      This version fixes a single major bug in the Conflux subsystem on the client
      side. See below for more information. The upcoming Tor Browser 13 stable will
      pick this up.
    
      o Major bugfixes (conflux):
        - Fix an issue that prevented us from pre-building more conflux sets
          after existing sets had been used. Fixes bug 40862; bugfix
          on 0.4.8.1-alpha.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on September 25, 2023.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2023/09/25.
    
    
    Changes in version 0.4.8.6 - 2023-09-18
      This version contains an important fix for onion service regarding congestion
      control and its reliability. Apart from that, unneeded BUG warnings have been
      suppressed especially about a compression bomb seen on relays. We strongly
      recommend, in particular onion service operators, to upgrade as soon as
      possible to this latest stable.
    
      o Major bugfixes (onion service):
        - Fix a reliability issue where services were expiring their
          introduction points every consensus update. This caused
          connectivity issues for clients caching the old descriptor and
          intro points. Bug reported and fixed by gitlab user
          @hyunsoo.kim676. Fixes bug 40858; bugfix on 0.4.7.5-alpha.
    
      o Minor features (debugging, compression):
        - Log the input and output buffer sizes when we detect a potential
          compression bomb. Diagnostic for ticket 40739.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on September 18, 2023.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2023/09/18.
    
      o Minor bugfix (defensive programming):
        - Disable multiple BUG warnings of a missing relay identity key when
          starting an instance of Tor compiled without relay support. Fixes
          bug 40848; bugfix on 0.4.3.1-alpha.
    
      o Minor bugfixes (bridge authority):
        - When reporting a pseudo-networkstatus as a bridge authority, or
          answering "ns/purpose/*" controller requests, include accurate
          published-on dates from our list of router descriptors. Fixes bug
          40855; bugfix on 0.4.8.1-alpha.
    
      o Minor bugfixes (compression, zstd):
        - Use less frightening language and lower the log-level of our run-
          time ABI compatibility check message in our Zstd compression
          subsystem. Fixes bug 40815; bugfix on 0.4.3.1-alpha.
    
    
    Changes in version 0.4.8.5 - 2023-08-30
      Quick second release after the first stable few days ago fixing minor
      annoying bugfixes creating log BUG stacktrace. We also fix BSD compilation
      failures and PoW unit test.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on August 30, 2023.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2023/08/30.
    
      o Minor bugfix (NetBSD, compilation):
        - Fix compilation issue on NetBSD by avoiding an unnecessary
          dependency on "huge" page mappings in Equi-X. Fixes bug 40843;
          bugfix on 0.4.8.1-alpha.
    
      o Minor bugfix (NetBSD, testing):
        - Fix test failures in "crypto/hashx" and "slow/crypto/equix" on
          x86_64 and aarch64 NetBSD hosts, by adding support for
          PROT_MPROTECT() flags. Fixes bug 40844; bugfix on 0.4.8.1-alpha.
    
      o Minor bugfixes (conflux):
        - Demote a relay-side warn about too many legs to ProtocolWarn, as
          there are conditions that it can briefly happen during set
          construction. Also add additional set logging details for all
          error cases. Fixes bug 40841; bugfix on 0.4.8.1-alpha.
        - Prevent non-fatal assert stacktrace caused by using conflux sets
          during their teardown process. Fixes bug 40842; bugfix
          on 0.4.8.1-alpha.
    
    
    Changes in version 0.4.8.4 - 2023-08-23
      Finally, this is the very first stable release of the 0.4.8.x series making,
      among other features, Proof-of-Work (prop#327) and Conflux (prop#329)
      available to the entire network. Several new features and a lot of bugfixes
      detailed below.
    
      o Major feature (denial of service):
        - Extend DoS protection to partially opened channels and known relays.
          Because re-entry is not allowed anymore, we can apply DoS protections
          onto known IP namely relays. Fixes bug 40821; bugfix on 0.3.5.1-alpha.
    
      o Major features (onion service, proof-of-work):
        - Implement proposal 327 (Proof-Of-Work). This is aimed at thwarting
          introduction flooding DoS attacks by introducing a dynamic Proof-Of-Work
          protocol that occurs over introduction circuits. This introduces several
          torrc options prefixed with "HiddenServicePoW" in order to control this
          feature. By default, this is disabled. Closes ticket 40634.
    
      o Major features (conflux):
        - Implement Proposal 329 (conflux traffic splitting). Conflux splits
          traffic across two circuits to Exits that support the protocol. These
          circuits are pre-built only, which means that if the pre- built conflux
          pool runs out, regular circuits will then be used. When using conflux
          circuit pairs, clients choose the lower-latency circuit to send data to
          the Exit. When the Exit sends data to the client, it maximizes
          throughput, by fully utilizing both circuits in a multiplexed fashion.
          Alternatively, clients can request that the Exit optimize for latency
          when transmitting to them, by setting the torrc option 'ConfluxClientUX
          latency'. Onion services are not currently supported, but will be in
          arti. Many other future optimizations will also be possible using this
          protocol. Closes ticket 40593.
    
      o Major features (dirauth):
        - Directory authorities and relays now interact properly with directory
          authorities if they change addresses. In the past, they would continue to
          upload votes, signatures, descriptors, etc to the hard-coded address in
          the configuration. Now, if the directory authority is listed in the
          consensus at a different address, they will direct queries to this new
          address. Implements ticket 40705.
    
      o Major bugfixes (conflux):
        - Fix a relay-side crash caused by side effects of the fix for bug
          40827. Reverts part of that fix that caused the crash and adds additional
          log messages to help find the root cause. Fixes bug 40834; bugfix on
          0.4.8.3-rc.
    
      o Major bugfixes (conflux):
        - Fix a relay-side assert crash caused by attempts to use a conflux circuit
          between circuit close and free, such that no legs were on the conflux
          set. Fixed by nulling out the stream's circuit back- pointer when the
          last leg is removed. Additional checks and log messages have been added
          to detect other cases. Fixes bug 40827; bugfix on 0.4.8.1-alpha.
    
      o Major bugfixes (proof of work, onion service, hashx):
        - Fix a very rare buffer overflow in hashx, specific to the dynamic
          compiler on aarch64 platforms. Fixes bug 40833; bugfix on 0.4.8.2-alpha.
    
      o Major bugfixes (vanguards):
        - Rotate to a new L2 vanguard whenever an existing one loses the Stable or
          Fast flag. Previously, we would leave these relays in the L2 vanguard
          list but never use them, and if all of our vanguards end up like this we
          wouldn't have any middle nodes left to choose from so we would fail to
          make onion-related circuits. Fixes bug 40805; bugfix on 0.4.7.1-alpha.
    
      o Minor features (bridge):
        - warn when a bridge is also configure to be an exit relay.
          Closes ticket 40819.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2023/08/23.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on August 23, 2023.
    
      o Minor features (testing):
        - All Rust code is now linted (cargo clippy) as part of GitLab CI, and
          existing warnings have been fixed. - Any unit tests written in Rust now
          run as part of GitLab CI.
    
      o Minor feature (CI):
        - Update CI to use Debian Bullseye for runners.
    
      o Minor feature (client, IPv6):
        - Make client able to pick IPv6 relays by default now meaning
          ClientUseIPv6 option now defaults to 1. Closes ticket 40785.
    
      o Minor feature (compilation):
        - Fix returning something other than "Unknown N/A" as libc version
          if we build tor on an O.S. like DragonFlyBSD, FreeBSD, OpenBSD
          or NetBSD.
    
      o Minor feature (cpuworker):
        - Always use the number of threads for our CPU worker pool to the
          number of core available but cap it to a minimum of 2 in case of a
          single core. Fixes bug 40713; bugfix on 0.3.5.1-alpha.
    
      o Minor feature (lzma):
        - Fix compiler warnings for liblzma >= 5.3.1. Closes ticket 40741.
    
      o Minor feature (MetricsPort, relay):
        - Expose time until online keys expires on the MetricsPort. Closes
          ticket 40546.
    
      o Minor feature (MetricsPort, relay, onion service):
        - Add metrics for the relay side onion service interactions counting
          seen cells. Closes ticket 40797. Patch by "friendly73".
    
      o Minor features (directory authorities):
        - Directory authorities now include their AuthDirMaxServersPerAddr
          config option in the consensus parameter section of their vote.
          Now external tools can better predict how they will behave.
          Implements ticket 40753.
    
      o Minor features (directory authority):
        - Add a new consensus method in which the "published" times on
          router entries in a microdesc consensus are all set to a
          meaningless fixed date. Doing this will make the download size for
          compressed microdesc consensus diffs much smaller. Part of ticket
          40130; implements proposal 275.
    
      o Minor features (network documents):
        - Clients and relays no longer track the "published on" time
          declared for relays in any consensus documents. When reporting
          this time on the control port, they instead report a fixed date in
          the future. Part of ticket 40130.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on June 01, 2023.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2023/06/01.
    
      o Minor features (hs, metrics):
        - Add tor_hs_rend_circ_build_time and tor_hs_intro_circ_build_time
          histograms to measure hidden service rend/intro circuit build time
          durations. Part of ticket 40757.
    
      o Minor features (metrics):
        - Add a `reason` label to the HS error metrics. Closes ticket 40758.
        - Add service side metrics for REND and introduction request
          failures. Closes ticket 40755.
        - Add support for histograms. Part of ticket 40757.
    
      o Minor features (pluggable transports):
        - Automatically restart managed Pluggable Transport processes when
          their process terminate. Resolves ticket 33669.
    
      o Minor features (portability, compilation):
        - Use OpenSSL 1.1 APIs for LibreSSL, fixing LibreSSL 3.5
          compatibility. Fixes issue 40630; patch by Alex Xu (Hello71).
    
      o Minor features (relay):
        - Do not warn about configuration options that may expose a non-
          anonymous onion service. Closes ticket 40691.
    
      o Minor features (relays):
        - Trigger OOS when bind fails with EADDRINUSE. This improves
          fairness when a large number of exit connections are requested,
          and properly signals exhaustion to the network. Fixes issue 40597;
          patch by Alex Xu (Hello71).
    
      o Minor features (tests):
        - Avoid needless key reinitialization with OpenSSL during unit
          tests, saving significant time. Patch from Alex Xu.
    
      o Minor bugfix (hs):
        - Fix compiler warnings in equix and hashx when building with clang.
          Closes ticket 40800.
    
      o Minor bugfix (FreeBSD, compilation):
        - Fix compilation issue on FreeBSD by properly importing
          sys/param.h. Fixes bug 40825; bugfix on 0.4.8.1-alpha.
    
      o Minor bugfixes (compression):
        - Right after compression/decompression work is done, check for
          errors. Before this, we would consider compression bomb before
          that and then looking for errors leading to false positive on that
          log warning. Fixes bug 40739; bugfix on 0.3.5.1-alpha. Patch
          by "cypherpunks".
    
      o Minor bugfixes (compilation):
        - Fix all -Werror=enum-int-mismatch warnings. No behavior change.
          Fixes bug 40824; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (protocol warn):
        - Wrap a handful of cases where ProtocolWarning logs could emit IP
          addresses. Fixes bug 40828; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfix (congestion control):
        - Reduce the accepted range of a circuit's negotiated 'cc_sendme_inc'
          to be +/- 1 from the consensus parameter value. Fixes bug 40569;
          bugfix on 0.4.7.4-alpha.
        - Remove unused congestion control algorithms and BDP calculation
          code, now that we have settled on and fully tuned Vegas. Fixes bug
          40566; bugfix on 0.4.7.4-alpha.
        - Update default congestion control parameters to match consensus.
          Fixes bug 40709; bugfix on 0.4.7.4-alpha.
    
      o Minor bugfixes (compilation):
        - Fix "initializer is not a constant" compilation error that
          manifests itself on gcc versions < 8.1 and MSVC. Fixes bug 40773;
          bugfix on 0.4.8.1-alpha
    
      o Minor bugfixes (conflux):
        - Count leg launch attempts prior to attempting to launch them. This
          avoids inifinite launch attempts due to internal circuit building
          failures. Additionally, double-check that we have enough exits in
          our consensus overall, before attempting to launch conflux sets.
          Fixes bug 40811; bugfix on 0.4.8.1-alpha.
        - Fix a case where we were resuming reading on edge connections that
          were already marked for close. Fixes bug 40801; bugfix
          on 0.4.8.1-alpha.
        - Fix stream attachment order when creating conflux circuits, so
          that stream attachment happens after finishing the full link
          handshake, rather than upon set finalization. Fixes bug 40801;
          bugfix on 0.4.8.1-alpha.
        - Handle legs being closed or destroyed before computing an RTT
          (resulting in warns about too many legs). Fixes bug 40810; bugfix
          on 0.4.8.1-alpha.
        - Remove a "BUG" warning from conflux_pick_first_leg that can be
          triggered by broken or malicious clients. Fixes bug 40801; bugfix
          on 0.4.8.1-alpha.
    
      o Minor bugfixes (KIST):
        - Prevent KISTSchedRunInterval from having values of 0 or 1, neither
          of which work properly. Additionally, make a separate
          KISTSchedRunIntervalClient parameter, so that the client and relay
          KIST values can be set separately. Set the default of both to 2ms.
          Fixes bug 40808; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfix (relay, logging):
        - The wrong max queue cell size was used in a protocol warning
          logging statement. Fixes bug 40745; bugfix on 0.4.7.1-alpha.
    
      o Minor bugfixes (logging):
        - Avoid ""double-quoting"" strings in several log messages. Fixes
          bug 22723; bugfix on 0.1.2.2-alpha.
        - Correct a log message when cleaning microdescriptors. Fixes bug
          40619; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (metrics):
        - Decrement hs_intro_established_count on introduction circuit
          close. Fixes bug 40751; bugfix on 0.4.7.12.
    
      o Minor bugfixes (pluggable transports, windows):
        - Remove a warning `BUG()` that could occur when attempting to
          execute a non-existing pluggable transport on Windows. Fixes bug
          40596; bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (relay):
        - Remove a "BUG" warning for an acceptable race between a circuit
          close and considering that circuit active. Fixes bug 40647; bugfix
          on 0.3.5.1-alpha.
        - Remove a harmless "Bug" log message that can happen in
          relay_addr_learn_from_dirauth() on relays during startup. Finishes
          fixing bug 40231. Fixes bug 40523; bugfix on 0.4.5.4-rc.
    
      o Minor bugfixes (sandbox):
        - Allow membarrier for the sandbox. And allow rt_sigprocmask when
          compiled with LTTng. Fixes bug 40799; bugfix on 0.3.5.1-alpha.
        - Fix sandbox support on AArch64 systems. More "*at" variants of
          syscalls are now supported. Signed 32 bit syscall parameters are
          checked more precisely, which should lead to lower likelihood of
          breakages with future compiler and libc releases. Fixes bug 40599;
          bugfix on 0.4.4.3-alpha.
    
      o Minor bugfixes (state file):
        - Avoid a segfault if the state file doesn't contains TotalBuildTimes
          along CircuitBuildAbandonedCount being above 0. Fixes bug 40437;
          bugfix on 0.3.5.1-alpha.
    
      o Removed features:
        - Remove the RendPostPeriod option. This was primarily used in
          Version 2 Onion Services and after its deprecation isn't needed
          anymore. Closes ticket 40431. Patch by Neel Chauhan.
    
    
    Changes in version 0.4.7.13 - 2023-01-12
      This version contains three major bugfixes, two for relays and one for
      client being a security fix, TROVE-2022-002. We have added, for Linux, the
      support for IP_BIND_ADDRESS_NO_PORT for relays using OutboundBindAddress.
      We strongly recommend to upgrade to this version considering the important
      congestion control fix detailed below.
    
      o Major bugfixes (congestion control):
        - Avoid incrementing the congestion window when the window is not
          fully in use. Thia prevents overshoot in cases where long periods
          of low activity would allow our congestion window to grow, and
          then get followed by a burst, which would cause queue overload.
          Also improve the increment checks for RFC3742. Fixes bug 40732;
          bugfix on 0.4.7.5-alpha.
    
      o Major bugfixes (relay):
        - When opening a channel because of a circuit request that did not
          include an Ed25519 identity, record the Ed25519 identity that we
          actually received, so that we can use the channel for other
          circuit requests that _do_ list an Ed25519 identity. (Previously
          we had code to record this identity, but a logic bug caused it to
          be disabled.) Fixes bug 40563; bugfix on 0.3.0.1-alpha. Patch
          from "cypherpunks".
    
      o Major bugfixes (TROVE-2022-002, client):
        - The SafeSocks option had its logic inverted for SOCKS4 and
          SOCKS4a. It would let the unsafe SOCKS4 pass but not the safe
          SOCKS4a one. This is TROVE-2022-002 which was reported on
          Hackerone by "cojabo". Fixes bug 40730; bugfix on 0.3.5.1-alpha.
    
      o Minor feature (authority):
        - Reject 0.4.6.x series at the authority level. Closes ticket 40664.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on January 12, 2023.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2023/01/12.
    
      o Minor features (relays):
        - Set the Linux-specific IP_BIND_ADDRESS_NO_PORT option on outgoing
          sockets, allowing relays using OutboundBindAddress to make more
          outgoing connections than ephemeral ports, as long as they are to
          separate destinations. Related to issue 40597; patch by Alex
          Xu (Hello71).
    
      o Minor bugfixes (relay, metrics):
        - Fix typo in a congestion control label on the MetricsPort. Fixes
          bug 40727; bugfix on 0.4.7.12.
    
      o Minor bugfixes (sandbox, authority):
        - With the sandbox enabled, allow to write "my-consensus-
          {ns|microdesc}" and to rename them as well. Fixes bug 40729;
          bugfix on 0.3.5.1-alpha.
    
      o Code simplifications and refactoring:
        - Rely on actual error returned by the kernel when choosing what
          resource exhaustion to log. Fixes issue 40613; Fix
          on tor-0.4.6.1-alpha.
    
    
    Changes in version 0.4.5.16 - 2023-01-12
      This version has one major bugfix for relay and a security fix,
      TROVE-2022-002, affecting clients. We strongly recommend to upgrade to our
      0.4.7.x stable series. As a reminder, this series is EOL on February 15th,
      2023.
    
      o Major bugfixes (relay):
        - When opening a channel because of a circuit request that did not
          include an Ed25519 identity, record the Ed25519 identity that we
          actually received, so that we can use the channel for other
          circuit requests that _do_ list an Ed25519 identity. (Previously
          we had code to record this identity, but a logic bug caused it to
          be disabled.) Fixes bug 40563; bugfix on 0.3.0.1-alpha. Patch
          from "cypherpunks".
    
      o Major bugfixes (TROVE-2022-002, client):
        - The SafeSocks option had its logic inverted for SOCKS4 and
          SOCKS4a. It would let the unsafe SOCKS4 pass but not the safe
          SOCKS4a one. This is TROVE-2022-002 which was reported on
          Hackerone by "cojabo". Fixes bug 40730; bugfix on 0.3.5.1-alpha.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on January 12, 2023.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2023/01/12.
    
    
    Changes in version 0.4.7.12 - 2022-12-06
      This version contains a major change that is a new key for moria1. Also, new
      metrics are exported on the MetricsPort for the congestion control
      subsystem.
    
      o Directory authority changes (moria1):
        - Rotate the relay identity key and v3 identity key for moria1. They
          have been online for more than a decade and refreshing keys
          periodically is good practice. Advertise new ports too, to avoid
          confusion. Closes ticket 40722.
    
      o Minor feature (Congestion control metrics):
        - Add additional metricsport relay metrics for congestion control.
          Closes ticket 40724.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on December 06, 2022.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2022/12/06.
    
      o Minor bugfixes (cpuworker, relay):
        - Fix an off by one overload calculation on the number of CPUs being
          used by our thread pool. Fixes bug 40719; bugfix on 0.3.5.1-alpha.
    
    
    Changes in version 0.4.5.15 - 2022-12-06
      This version has several major changes for directory authorities. And a
      major bugfix on OSX. Again, we strongly recommend to upgrade to our 0.4.7.x
      series latest stable. This series is EOL on February 15th, 2023.
    
      o Directory authority changes (dizum):
        - Change dizum IP address. Closes ticket 40687.
    
      o Directory authority changes (Faravahar):
        - Remove Faravahar until its operator, Sina, set it back up online
          outside of Team Cymru network. Closes ticket 40688.
    
      o Directory authority changes (moria1):
        - Rotate the relay identity key and v3 identity key for moria1. They
          have been online for more than a decade and refreshing keys
          periodically is good practice. Advertise new ports too, to avoid
          confusion. Closes ticket 40722.
    
      o Major bugfixes (OSX):
        - Fix coarse-time computation on Apple platforms (like Mac M1) where
          the Mach absolute time ticks do not correspond directly to
          nanoseconds. Previously, we computed our shift value wrong, which
          led us to give incorrect timing results. Fixes bug 40684; bugfix
          on 0.3.3.1-alpha.
    
      o Major bugfixes (relay):
        - Improve security of our DNS cache by randomly clipping the TTL
          value. TROVE-2021-009. Fixes bug 40674; bugfix on 0.3.5.1-alpha.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on December 06, 2022.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2022/12/06.
    
    
    Changes in version 0.4.7.11 - 2022-11-10
      This version contains several major fixes aimed at helping defend against
      network denial of service. It is also extending drastically the MetricsPort
      for relays to help us gather more internal data to investigate performance
      and attacks.
    
      We strongly recommend to upgrade to this version especially for Exit relays
      in order to help the network defend against this ongoing DDoS.
    
      o Directory authority changes (dizum, Faravahar):
        - Change dizum IP address. Closes ticket 40687.
        - Remove Faravahar until its operator, Sina, set it back up online
          outside of Team Cymru network. Closes ticket 40688.
    
      o Major bugfixes (geoip data):
        - IPFire informed us on August 12th that databases generated after
          (including) August 10th did not have proper ARIN network
          allocations. We are updating the database to use the one generated
          on August 9th, 2022. Fixes bug 40658; bugfix on 0.4.5.13.
    
      o Major bugfixes (onion service):
        - Set a much higher circuit build timeout for opened client rendezvous
          circuit. Before this, tor would time them out very quickly leading to
          unnecessary retries meaning more load on the network. Fixes bug 40694;
          bugfix on 0.3.5.1-alpha.
    
      o Major bugfixes (OSX):
        - Fix coarse-time computation on Apple platforms (like Mac M1) where
          the Mach absolute time ticks do not correspond directly to
          nanoseconds. Previously, we computed our shift value wrong, which
          led us to give incorrect timing results. Fixes bug 40684; bugfix
          on 0.3.3.1-alpha.
    
      o Major bugfixes (relay):
        - Improve security of our DNS cache by randomly clipping the TTL
          value. TROVE-2021-009. Fixes bug 40674; bugfix on 0.3.5.1-alpha.
    
      o Minor feature (Mac and iOS build):
        - Change how combine_libs works on Darwin like platforms to make
          sure we don't include any `__.SYMDEF` and `__.SYMDEF SORTED`
          symbols on the archive before we repack and run ${RANLIB} on the
          archive. This fixes a build issue with recent Xcode versions on
          Mac Silicon and iOS. Closes ticket 40683.
    
      o Minor feature (metrics):
        - Add various congestion control counters to the MetricsPort. Closes
          ticket 40708.
    
      o Minor feature (performance):
        - Bump the maximum amount of CPU that can be used from 16 to 128. Note
          that NumCPUs torrc option overrides this hardcoded maximum. Fixes bug
          40703; bugfix on 0.3.5.1-alpha.
    
      o Minor feature (relay):
        - Make an hardcoded value for the maximum of per CPU tasks into a
          consensus parameter.
        - Two new consensus parameters are added to control the wait time in
          queue of the onionskins. One of them is the torrc
          MaxOnionQueueDelay options which supersedes the consensus
          parameter. Closes ticket 40704.
    
      o Minor feature (relay, DoS):
        - Apply circuit creation anti-DoS defenses if the outbound circuit
          max cell queue size is reached too many times. This introduces two
          new consensus parameters to control the queue size limit and
          number of times allowed to go over that limit. Closes ticket 40680.
    
      o Minor feature (relay, metrics):
        - Add DoS defenses counter to MetricsPort.
        - Add congestion control RTT reset counter to MetricsPort.
        - Add counters to the MetricsPort how many connections, per type,
          are currently opened and how many were created.
        - Add relay flags from the consensus to the MetricsPort.
        - Add total number of opened circuits to MetricsPort.
        - Add total number of streams seen by an Exit to the MetricsPort.
        - Add traffic stats as in number of read/written bytes in total.
        - Related to ticket 40194.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on November 10, 2022.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2022/11/10.
    
      o Minor bugfixes (authorities, sandbox):
        - Allow to write file my-consensus-<flavor-name> to disk when
          sandbox is activated. Fixes bug 40663; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (dirauth):
        - Directory authorities stop voting a consensus "Measured" weight
          for relays with the Authority flag. Now these relays will be
          considered unmeasured, which should reserve their bandwidth for
          their dir auth role and minimize distractions from other roles. In
          place of the "Measured" weight, they now include a
          "MeasuredButAuthority" weight (not used by anything) so the
          bandwidth authority's opinion on this relay can be recorded for
          posterity. Lastly, remove the AuthDirDontVoteOnDirAuthBandwidth
          torrc option which never worked right. Fixes bugs 40698 and 40700;
          bugfix on 0.4.7.2-alpha.
    
      o Minor bugfixes (onion service client):
        - A collapsing onion service circuit should be seen as an
          "unreachable" error so it can be retried. Fixes bug 40692; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (onion service):
        - Make the service retry a rendezvous if the circuit is being
          repurposed for measurements. Fixes bug 40696; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (relay overload statistics):
        - Count total create cells vs dropped create cells properly, when
          assessing if our fraction of dropped cells is too high. We only
          count non-client circuits in the denominator, but we would include
          client circuits in the numerator, leading to surprising log lines
          claiming that we had dropped more than 100% of incoming create
          cells. Fixes bug 40673; bugfix on 0.4.7.1-alpha.
    
      o Code simplification and refactoring (bridges):
        - Remove unused code related to ExtPort connection ID. Fixes bug
          40648; bugfix on 0.3.5.1-alpha.
    
    
    Changes in version 0.4.7.10 - 2022-08-12
      This version updates the geoip cache that we generate from IPFire location
      database to use the August 9th, 2022 one. Everyone MUST update to this
      latest release else circuit path selection and relay metrics are badly
      affected.
    
      o Major bugfixes (geoip data):
        - IPFire informed us on August 12th that databases generated after
          (including) August 10th did not have proper ARIN network allocations. We
          are updating the database to use the one generated on August 9th, 2022.
          Fixes bug 40658; bugfix on 0.4.7.9.
    
    
    Changes in version 0.4.6.12 - 2022-08-12
      This version updates the geoip cache that we generate from IPFire location
      database to use the August 9th, 2022 one. Everyone MUST update to this
      latest release else circuit path selection and relay metrics are badly
      affected.
    
      o Major bugfixes (geoip data):
        - IPFire informed us on August 12th that databases generated after
          (including) August 10th did not have proper ARIN network allocations. We
          are updating the database to use the one generated on August 9th, 2022.
          Fixes bug 40658; bugfix on 0.4.6.11.
    
    
    Changes in version 0.4.5.14 - 2022-08-12
      This version updates the geoip cache that we generate from IPFire location
      database to use the August 9th, 2022 one. Everyone MUST update to this
      latest release else circuit path selection and relay metrics are badly
      affected.
    
      o Major bugfixes (geoip data):
        - IPFire informed us on August 12th that databases generated after
          (including) August 10th did not have proper ARIN network allocations. We
          are updating the database to use the one generated on August 9th, 2022.
          Fixes bug 40658; bugfix on 0.4.5.13.
    
    
    Changes in version 0.4.7.9 - 2022-08-11
      This version contains several major fixes aimed at reducing memory pressure on
      relays and possible side-channel. It also contains a major bugfix related to
      congestion control also aimed at reducing memory pressure on relays.
      Finally, there is last one major bugfix related to Vanguard L2 layer node
      selection.
    
      We strongly recommend to upgrade to this version especially for Exit relays
      in order to help the network defend against this ongoing DDoS.
    
      o Major bugfixes (congestion control):
        - Implement RFC3742 Limited Slow Start. Congestion control was
          overshooting the congestion window during slow start, particularly
          for onion service activity. With this fix, we now update the
          congestion window more often during slow start, as well as dampen
          the exponential growth when the congestion window grows above a
          capping parameter. This should reduce the memory increases guard
          relays were seeing, as well as allow us to set lower queue limits
          to defend against ongoing DoS attacks. Fixes bug 40642; bugfix
          on 0.4.7.5-alpha.
    
      o Major bugfixes (relay):
        - Remove OR connections btrack subsystem entries when the connections
          close normally. Before this, we would only remove the entry on error and
          thus leaking memory for each normal OR connections. Fixes bug 40604;
          bugfix on 0.4.0.1-alpha.
        - Stop sending TRUNCATED cell and instead close the circuit from which we
          received a DESTROY cell. This makes every relay in the circuit path to
          stop queuing cells. Fixes bug 40623; bugfix on 0.1.0.2-rc.
    
      o Major bugfixes (vanguards):
        - We had omitted some checks for whether our vanguards (second layer
          guards from proposal 333) overlapped. Now make sure to pick each
          of them to be independent. Also, change the design to allow them
          to come from the same family. Fixes bug 40639; bugfix
          on 0.4.7.1-alpha.
    
      o Minor features (dirauth):
        - Add a torrc option to control the Guard flag bandwidth threshold
          percentile. Closes ticket 40652.
        - Add an AuthDirVoteGuard torrc option that can allow authorities to
          assign the Guard flag to the given fingerprints/country code/IPs.
          This is a needed feature mostly for defense purposes in case a DoS
          hits the network and relay start losing the Guard flags too fast.
        - Make UPTIME_TO_GUARANTEE_STABLE, MTBF_TO_GUARANTEE_STABLE,
          TIME_KNOWN_TO_GUARANTEE_FAMILIAR WFU_TO_GUARANTEE_GUARD tunable
          from torrc.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on August 11, 2022.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2022/08/11.
    
      o Minor bugfixes (congestion control):
        - Add a check for an integer underflow condition that might happen
          in cases where the system clock is stopped, the ORconn is blocked,
          and the endpoint sends more than a congestion window worth of non-
          data control cells at once. This would cause a large congestion
          window to be calculated instead of a small one. No security
          impact. Fixes bug 40644; bugfix on 0.4.7.5-alpha.
    
      o Minor bugfixes (defense in depth):
        - Change a test in the netflow padding code to make it more
          _obviously_ safe against remotely triggered crashes. (It was safe
          against these before, but not obviously so.) Fixes bug 40645;
          bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (relay):
        - Do not propagate either forward or backward a DESTROY remote reason when
          closing a circuit in order to avoid a possible side channel. Fixes bug
          40649; bugfix on 0.1.2.4-alpha.
    
    
    Changes in version 0.4.6.11 - 2022-08-11
      This version contains two major fixes aimed at reducing memory pressure on
      relays and possible side-channel. The rest of the fixes were backported for
      stability or safety purposes.
    
      This is the very LAST version of this series. As of August 1st 2022, it is
      end-of-life (EOL). We thus strongly recommend to upgrade to the latest
      stable of the 0.4.7.x series.
    
      o Major bugfixes (relay):
        - Remove OR connections btrack subsystem entries when the connections
          close normally. Before this, we would only remove the entry on error and
          thus leaking memory for each normal OR connections. Fixes bug 40604;
          bugfix on 0.4.0.1-alpha.
        - Stop sending TRUNCATED cell and instead close the circuit from which we
          received a DESTROY cell. This makes every relay in the circuit path to
          stop queuing cells. Fixes bug 40623; bugfix on 0.1.0.2-rc.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on August 11, 2022.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2022/08/11.
    
      o Minor features (linux seccomp2 sandbox):
        - Permit the clone3 syscall, which is apparently used in glibc-2.34
          and later. Closes ticket 40590.
    
      o Minor bugfixes (controller, path bias):
        - When a circuit's path is specified, in full or in part, from the
          controller API, do not count that circuit towards our path-bias
          calculations. (Doing so was incorrect, since we cannot tell
          whether the controller is selecting relays randomly.) Resolves a
          "Bug" warning. Fixes bug 40515; bugfix on 0.2.4.10-alpha.
    
      o Minor bugfixes (defense in depth):
        - Change a test in the netflow padding code to make it more
          _obviously_ safe against remotely triggered crashes. (It was safe
          against these before, but not obviously so.) Fixes bug 40645;
          bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (linux seccomp2 sandbox):
        - Allow the rseq system call in the sandbox. This solves a crash
          issue with glibc 2.35 on Linux. Patch from pmu-ipf. Fixes bug
          40601; bugfix on 0.3.5.11.
    
      o Minor bugfixes (metrics port, onion service):
        - The MetricsPort line for an onion service with multiple ports are now
          unique that is one line per port. Before this, all ports of an onion
          service would be on the same line which violates the Prometheus rules of
          unique labels. Fixes bug 40581; bugfix on 0.4.5.1-alpha.
    
      o Minor bugfixes (onion service, client):
        - Fix a fatal assert due to a guard subsystem recursion triggered by
          the onion service client. Fixes bug 40579; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (performance, DoS):
        - Fix one case of a not-especially viable denial-of-service attack
          found by OSS-Fuzz in our consensus-diff parsing code. This attack
          causes a lot small of memory allocations and then immediately
          frees them: this is only slow when running with all the sanitizers
          enabled. Fixes one case of bug 40472; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (relay):
        - Do not propagate either forward or backward a DESTROY remote reason when
          closing a circuit in order to avoid a possible side channel. Fixes bug
          40649; bugfix on 0.1.2.4-alpha.
    
    
    Changes in version 0.4.5.13 - 2022-08-11
      This version contains two major fixes aimed at reducing memory pressure on
      relays and possible side-channel. The rest of the fixes were backported for
      stability or safety purposes. We strongly recommend to upgrade your relay to
      this version or, ideally, to the latest stable of the 0.4.7.x series.
    
      o Major bugfixes (relay):
        - Remove OR connections btrack subsystem entries when the connections
          close normally. Before this, we would only remove the entry on error and
          thus leaking memory for each normal OR connections. Fixes bug 40604;
          bugfix on 0.4.0.1-alpha.
        - Stop sending TRUNCATED cell and instead close the circuit from which we
          received a DESTROY cell. This makes every relay in the circuit path to
          stop queuing cells. Fixes bug 40623; bugfix on 0.1.0.2-rc.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on August 11, 2022.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2022/08/11.
    
      o Minor features (linux seccomp2 sandbox):
        - Permit the clone3 syscall, which is apparently used in glibc-2.34
          and later. Closes ticket 40590.
    
      o Minor bugfixes (controller, path bias):
        - When a circuit's path is specified, in full or in part, from the
          controller API, do not count that circuit towards our path-bias
          calculations. (Doing so was incorrect, since we cannot tell
          whether the controller is selecting relays randomly.) Resolves a
          "Bug" warning. Fixes bug 40515; bugfix on 0.2.4.10-alpha.
    
      o Minor bugfixes (defense in depth):
        - Change a test in the netflow padding code to make it more
          _obviously_ safe against remotely triggered crashes. (It was safe
          against these before, but not obviously so.) Fixes bug 40645;
          bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (linux seccomp2 sandbox):
        - Allow the rseq system call in the sandbox. This solves a crash
          issue with glibc 2.35 on Linux. Patch from pmu-ipf. Fixes bug
          40601; bugfix on 0.3.5.11.
    
      o Minor bugfixes (metrics port, onion service):
        - The MetricsPort line for an onion service with multiple ports are now
          unique that is one line per port. Before this, all ports of an onion
          service would be on the same line which violates the Prometheus rules of
          unique labels. Fixes bug 40581; bugfix on 0.4.5.1-alpha.
    
      o Minor bugfixes (onion service, client):
        - Fix a fatal assert due to a guard subsystem recursion triggered by
          the onion service client. Fixes bug 40579; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (performance, DoS):
        - Fix one case of a not-especially viable denial-of-service attack
          found by OSS-Fuzz in our consensus-diff parsing code. This attack
          causes a lot small of memory allocations and then immediately
          frees them: this is only slow when running with all the sanitizers
          enabled. Fixes one case of bug 40472; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (relay):
        - Do not propagate either forward or backward a DESTROY remote reason when
          closing a circuit in order to avoid a possible side channel. Fixes bug
          40649; bugfix on 0.1.2.4-alpha.
    
    
    Changes in version 0.4.7.8 - 2022-06-17
      This version fixes several bugfixes including a High severity security issue
      categorized as a Denial of Service. Everyone running an earlier version
      should upgrade to this version.
    
      o Major bugfixes (congestion control, TROVE-2022-001):
        - Fix a scenario where RTT estimation can become wedged, seriously
          degrading congestion control performance on all circuits. This
          impacts clients, onion services, and relays, and can be triggered
          remotely by a malicious endpoint. Tracked as CVE-2022-33903. Fixes
          bug 40626; bugfix on 0.4.7.5-alpha.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on June 17, 2022.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2022/06/17.
    
      o Minor bugfixes (linux seccomp2 sandbox):
        - Allow the rseq system call in the sandbox. This solves a crash
          issue with glibc 2.35 on Linux. Patch from pmu-ipf. Fixes bug
          40601; bugfix on 0.3.5.11.
    
      o Minor bugfixes (logging):
        - Demote a harmless warn log message about finding a second hop to
          from warn level to info level, if we do not have enough
          descriptors yet. Leave it at notice level for other cases. Fixes
          bug 40603; bugfix on 0.4.7.1-alpha.
        - Demote a notice log message about "Unexpected path length" to info
          level. These cases seem to happen arbitrarily, and we likely will
          never find all of them before the switch to arti. Fixes bug 40612;
          bugfix on 0.4.7.5-alpha.
    
      o Minor bugfixes (relay, logging):
        - Demote a harmless XOFF log message to from notice level to info
          level. Fixes bug 40620; bugfix on 0.4.7.5-alpha.
    
    
    Changes in version 0.4.7.7 - 2022-04-27
      This is the first stable version of the 0.4.7.x series. This series
      includes several major bugfixes from previous series and several features
      including one massive new one: congestion control.
    
      Congestion control, among other things, should improve traffic speed and
      stability on the network once a majority of Exit upgrade. You can find more
      details about it in proposal 324 in the torspec.git repository.
    
      Below are all the changes of the 0.4.7.x series:
    
      o Major features (congestion control):
        - Implement support for flow control over congestion controlled
          circuits. This work comes from proposal 324. Closes ticket 40450.
    
      o Major features (relay, client, onion services):
        - Implement RTT-based congestion control for exits and onion
          services, from Proposal 324. Disabled by default. Enabled by the
          'cc_alg' consensus parameter. Closes ticket 40444.
    
      o Major features (directory authority):
        - Add a new consensus method to handle MiddleOnly specially. When
          enough authorities are using this method, then any relay tagged
          with the MiddleOnly flag will have its Exit, Guard, HSDir, and
          V2Dir flags automatically cleared, and will have its BadExit flag
          automatically set. Implements part of proposal 335.
        - Authorities can now be configured to label relays as "MiddleOnly".
          When voting for this flag, authorities automatically vote against
          Exit, Guard, HSDir, and V2Dir; and in favor of BadExit. Implements
          part of proposal 335. Based on a patch from Neel Chauhan.
    
      o Major features (Proposal 332, onion services, guard selection algorithm):
        - Clients and onion services now choose four long-lived "layer 2"
          guard relays for use as the middle hop in all onion circuits.
          These relays are kept in place for a randomized duration averaging
          1 week. This mitigates guard discovery attacks against clients and
          short-lived onion services such as OnionShare. Long-lived onion
          services that need high security should still use the Vanguards
          addon (https://github.com/mikeperry-tor/vanguards). Closes ticket
          40363; implements proposal 333.
    
      o Major bugfix (relay, metrics):
        - On the MetricsPort, the DNS error statistics are not reported by
          record type ("record=...") anymore due to a libevent bug
          (https://github.com/libevent/libevent/issues/1219). Fixes bug
          40490; bugfix on 0.4.7.1-alpha.
    
      o Major bugfixes (bridges):
        - Make Tor work reliably again when you have multiple bridges
          configured and one or more of them are unreachable. The problem
          came because we require that we have bridge descriptors for both
          of our first two bridges (else we refuse to try to connect), but
          in some cases we would wait three hours before trying to fetch
          these missing descriptors, and/or never recover when we do try to
          fetch them. Fixes bugs 40396 and 40495; bugfix on 0.3.0.5-rc
          and 0.3.2.1-alpha.
    
      o Major bugfixes (client):
        - Stop caching TCP connect failures to relays/bridges when we
          initiated the connection as a client. Now we only cache connect
          failures as a relay or bridge when we initiated them because of an
          EXTEND request. Declining to re-attempt the client-based
          connections could cause problems when we lose connectivity and try
          to reconnect. Fixes bug 40499; bugfix on 0.3.3.4-alpha.
    
      o Major bugfixes (onion service, congestion control):
        - Fix the onion service upload case where the congestion control
          parameters were not added to the right object. Fixes bug 40586;
          bugfix on 0.4.7.4-alpha.
    
      o Major bugfixes (relay, DNS):
        - Lower the DNS timeout from 3 attempts at 5 seconds each to 2
          attempts at 1 seconds each. Two new consensus parameters were
          added to control these values. This change should improve observed
          performance under DNS load; see ticket for more details. Fixes bug
          40312; bugfix on 0.3.5.1-alpha.
    
      o Major bugfixes (relay, overload state):
        - Relays report the general overload state for DNS timeout errors
          only if X% of all DNS queries over Y seconds are errors. Before
          that, it only took 1 timeout to report the overload state which
          was just too low of a threshold. The X and Y values are 1% and 10
          minutes respectively but they are also controlled by consensus
          parameters. Fixes bug 40491; bugfix on 0.4.6.1-alpha.
    
      o Major bugfixes (relay, overload):
        - Do not trigger a general overload on DNS timeout. Even after
          fixing 40527, some code remained that triggered the overload.
          Fixes bug 40564; bugfix on 0.4.7.1-alpha.
        - Change the MetricsPort DNS "timeout" label to be "tor_timeout" in
          order to indicate that this was a DNS timeout from tor perspective
          and not the DNS server itself.
        - Deprecate overload_dns_timeout_period_secs and
          overload_dns_timeout_scale_percent consensus parameters as well.
          They were used to assess the overload state which is no more now.
        - Don't make Tor DNS timeout trigger an overload general state.
          These timeouts are different from DNS server timeout. They have to
          be seen as timeout related to UX and not because of a network
          problem. Fixes bug 40527; bugfix on 0.4.6.1-alpha.
    
      o Minor feature (authority, relay):
        - Reject End-Of-Life relays running version 0.4.2.x, 0.4.3.x,
          0.4.4.x and 0.4.5 alphas/rc. Closes ticket 40480.
        - Reject End-Of-Life relays running version 0.3.5.x. Closes
          ticket 40559.
    
      o Minor feature (onion service v2):
        - Onion service v2 addresses are now not recognized anymore by tor
          meaning a bad hostname is returned when attempting to pass it on a
          SOCKS connection. No more deprecation log is emitted client side.
          Closes ticket 40476.
        - See https://blog.torproject.org/v2-deprecation-timeline for
          details on how to transition from v2 to v3.
    
      o Minor feature (reproducible build):
        - The repository can now build reproducible tarballs which adds the
          build command "make dist-reprod" for that purpose. Closes
          ticket 26299.
    
      o Minor features (bridge testing support):
        - Let external bridge reachability testing tools discard cached
          bridge descriptors when setting new bridges, so they can be sure
          to get a clean reachability test. Implements ticket 40209.
    
      o Minor features (compilation):
        - Give an error message if trying to build with a version of
          LibreSSL known not to work with Tor. (There's an incompatibility
          with LibreSSL versions 3.2.1 through 3.4.0 inclusive because of
          their incompatibility with OpenSSL 1.1.1's TLSv1.3 APIs.) Closes
          ticket 40511.
    
      o Minor features (control port):
        - Provide congestion control fields on CIRC_BW and STREAM control
          port events, for use by sbws. Closes ticket 40568.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on April 27, 2022.
    
      o Minor features (fuzzing):
        - When building with --enable-libfuzzer, use a set of compiler flags
          that works with more recent versions of the library. Previously we
          were using a set of flags from 2017. Closes ticket 40407.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2022/04/27.
    
      o Minor features (logging, heartbeat):
        - When a relay receives a cell that isn't encrypted properly for it,
          but the relay is the last hop on the circuit, the relay now counts
          how many cells of this kind it receives, on how many circuits, and
          reports this information in the log. Previously, we'd log each
          cell at PROTOCOL_WARN level, which is far too verbose to be
          useful. Fixes part of ticket 40400.
    
      o Minor features (portability):
        - Try to prevent a compiler warning about printf arguments that
          could sometimes occur on MSYS2 depending on the configuration.
          Closes ticket 40355.
    
      o Minor features (testing configuration):
        - When TestingTorNetwork is enabled, skip the permissions check on
          hidden service directories. Closes ticket 40338.
        - On a testing network, relays can now use the
          TestingMinTimeToReportBandwidth option to change the smallest
          amount of time over which they're willing to report their observed
          maximum bandwidth. Previously, this was fixed at 1 day. For
          safety, values under 2 hours are only supported on testing
          networks. Part of a fix for ticket 40337.
        - Relays on testing networks no longer rate-limit how frequently
          they are willing to report new bandwidth measurements. Part of a
          fix for ticket 40337.
        - Relays on testing networks now report their observed bandwidths
          immediately from startup. Previously, they waited until they had
          been running for a full day. Closes ticket 40337.
    
      o Minor features (testing):
        - We now have separate fuzzers for the inner layers of v3 onion
          service descriptors, to prevent future bugs like 40392. Closes
          ticket 40488.
    
      o Minor bugfix (CI, onion service):
        - Exclude onion service version 2 Stem tests in our CI. Fixes bug
          40500; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfix (logging):
        - Update a log notice dead URL to a working one. Fixes bug 40544;
          bugfix on 0.3.5.1-alpha.
    
      o Minor bugfix (pluggable transport):
        - Do not kill a managed proxy if one of its transport configurations
          emits a method error. Instead log a warning and continue processing
          method arguments. Fixes bug 7362; bugfix on 0.2.3.6-alpha.
    
      o Minor bugfix (relay):
        - Remove the HSDir and HSIntro onion service v2 protocol versions so
          relay stop advertising that they support them. Fixes bug 40509;
          bugfix on 0.3.5.17.
    
      o Minor bugfixes (bridges):
        - When we don't yet have a descriptor for one of our bridges,
          disable the entry guard retry schedule on that bridge. The entry
          guard retry schedule and the bridge descriptor retry schedule can
          conflict, e.g. where we mark a bridge as "maybe up" yet we don't
          try to fetch its descriptor yet, leading Tor to wait (refusing to
          do anything) until it becomes time to fetch the descriptor. Fixes
          bug 40497; bugfix on 0.3.0.3-alpha.
    
      o Minor bugfixes (cell scheduling):
        - Avoid writing empty payload with NSS write.
        - Don't attempt to write 0 bytes after a cell scheduling loop. No
          empty payload was put on the wire. Fixes bug 40548; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (circuit padding):
        - Don't send STOP circuit padding cells when the other side has
          already shut down the corresponding padding machine. Fixes bug
          40435; bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (compatibility):
        - Fix compatibility with the most recent Libevent versions, which no
          longer have an evdns_set_random_bytes() function. Because this
          function has been a no-op since Libevent 2.0.4-alpha, it is safe
          for us to just stop calling it. Fixes bug 40371; bugfix
          on 0.2.1.7-alpha.
    
      o Minor bugfixes (compilation):
        - Fix compilation error when __NR_time is not defined. Fixes bug
          40465; bugfix on 0.2.5.5-alpha. Patch by Daniel Pinto.
        - Fix our configuration logic to detect whether we had OpenSSL 3:
          previously, our logic was reversed. This has no other effect than
          to change whether we suppress deprecated API warnings. Fixes bug
          40429; bugfix on 0.3.5.13.
        - Resume being able to build on old / esoteric gcc versions. Fixes
          bug 40550; bugfix on 0.4.7.1-alpha.
    
      o Minor bugfixes (compiler warnings):
        - Fix couple compiler warnings on latest Ubuntu Jammy. Fixes bug
          40516; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (congestion control, client side logs):
        - Demote a warn about 1-hop circuits using congestion control down
          to info; Demote the 4-hop case to notice. Fixes bug 40598; bugfix
          on 0.4.5-alpha.
    
      o Minor bugfixes (control, sandbox):
        - Allows the control command SAVECONF to succeed when the seccomp
          sandbox is enabled. Makes SAVECONF keep only one backup file, to
          simplify implementation. Fixes bug 40317; bugfix on 0.2.5.4-alpha.
          Patch by Daniel Pinto.
    
      o Minor bugfixes (controller, path bias):
        - When a circuit's path is specified, in full or in part, from the
          controller API, do not count that circuit towards our path-bias
          calculations. (Doing so was incorrect, since we cannot tell
          whether the controller is selecting relays randomly.) Resolves a
          "Bug" warning. Fixes bug 40515; bugfix on 0.2.4.10-alpha.
    
      o Minor bugfixes (dirauth, bandwidth scanner):
        - Add the AuthDirDontVoteOnDirAuthBandwidth dirauth config parameter
          to avoid voting on bandwidth scanner weights to v3 directory
          authorities. Fixes bug 40471; bugfix on 0.2.2.1-alpha. Patch by
          Neel Chauhan.
    
      o Minor bugfixes (DNSPort, dormant mode):
        - A request on the DNSPort now wakes up a dormant tor. Fixes bug
          40577; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (fragile-hardening, sandbox):
        - When building with --enable-fragile-hardening, add or relax Linux
          seccomp rules to allow AddressSanitizer to execute normally if the
          process terminates with the sandbox active. This has the side
          effect of disabling the filtering of file- and directory-open
          requests on most systems and dilutes the effectiveness of the
          sandbox overall, as a wider range of system calls must be
          permitted. Fixes bug 11477; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (heartbeat):
        - Adjust the heartbeat log message about distinct clients to
          consider the HeartbeatPeriod rather than a flat 6-hour delay.
          Fixes bug 40330; bugfix on 0.2.6.3-alpha.
    
      o Minor bugfixes (logging):
        - If a channel has never received or transmitted a cell, or seen a
          client, do not calculate time diffs against 1/1/1970 but log a
          better prettier message. Fixes bug 40182; bugfix on 0.2.4.4.
        - When we no longer have enough directory information to use the
          network, we would log a notice-level message -- but we would not
          reliably log a message when we recovered and resumed using the
          network. Now make sure there is always a corresponding message
          about recovering. Fixes bug 40496; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (logging, relay):
        - Add spaces between the "and" when logging the "Your server has not
          managed to confirm reachability for its" on dual-stack relays.
          Fixes bug 40453; bugfix on 0.4.5.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (metrics port, onion service):
        - Fix the metrics with a port label to be unique. Before this, all
          ports of an onion service would be on the same line which violates
          the Prometheus rules of unique labels. Fixes bug 40581; bugfix
          on 0.4.5.1-alpha.
    
      o Minor bugfixes (onion service congestion control):
        - Avoid a non-fatal assertion failure in the case where we fail to
          set up congestion control on a rendezvous circuit. This could
          happen naturally if a cache entry expired at an unexpected time.
          Fixes bug 40576; bugfix on 0.4.7.4-alpha.
    
      o Minor bugfixes (onion service):
        - Do not flag an HSDir as non-running in case the descriptor upload
          or fetch fails. An onion service closes pending directory
          connections before uploading a new descriptor which leads to
          wrongly flagging many relays and thus affecting circuit path
          selection. Fixes bug 40434; bugfix on 0.2.0.13-alpha.
        - Fix a warning BUG that would occur often on heavily loaded onion
          service leading to filling the logs with useless warnings. Fixes
          bug 34083; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion service, client):
        - Fix a rare but fatal assertion failure due to a guard subsystem
          recursion triggered by the onion service client. Fixes bug 40579;
          bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (onion service, config):
        - Fix a memory leak for a small config line string that could occur
          if the onion service failed to be configured from file properly.
          Fixes bug 40484; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion service, TROVE-2021-008):
        - Only log v2 access attempts once total, in order to not pollute
          the logs with warnings and to avoid recording the times on disk
          when v2 access was attempted. Note that the onion address was
          _never_ logged. This counts as a Low-severity security issue.
          Fixes bug 40474; bugfix on 0.4.5.8.
        - Note that due to #40476 which removes v2 support entirely, this
          log line is not emitted anymore. We still mention this in the
          changelog because it is a Low-severity TROVE.
    
      o Minor bugfixes (performance, DoS):
        - Fix one case of a not-especially viable denial-of-service attack
          found by OSS-Fuzz in our consensus-diff parsing code. This attack
          causes a lot small of memory allocations and then immediately
          frees them: this is only slow when running with all the sanitizers
          enabled. Fixes one case of bug 40472; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (relay):
        - Reject IPv6-only DirPorts. Our reachability self-test forces
          DirPorts to be IPv4, but our configuration parser allowed them to
          be IPv6-only, which led to an assertion failure. Fixes bug 40494;
          bugfix on 0.4.5.1-alpha.
    
      o Minor bugfixes (relay, overload):
        - Decide whether to signal overload based on a fraction and
          assessment period of ntor handshake drops. Previously, a single
          drop could trigger an overload state, which caused many false
          positives. Fixes bug 40560; bugfix on 0.4.7.1-alpha.
    
      o Minor bugfixes (sandbox):
        - Fix the sandbox on i386 by modifying it to allow the
          "clock_gettime64" and "statx" system calls and to filter the
          "chown32" and "stat64" system calls in place of "chown" and
          "stat", respectively. Fixes bug 40505; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (statistics):
        - Fix a fencepost issue when we check stability_last_downrated where
          we called rep_hist_downrate_old_runs() twice. Fixes bug 40394;
          bugfix on 0.2.0.5-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (tests):
        - Fix a bug that prevented some tests from running with the correct
          names. Fixes bug 40365; bugfix on 0.4.3.1-alpha.
    
      o Minor bugfixes (usability):
        - Do not log "RENDEZVOUS1 cell with unrecognized rendezvous cookie"
          at LOG_PROTOCOL_WARN; instead log it at DEBUG. This warning can
          happen naturally if a client gives up on a rendezvous circuit
          after sending INTRODUCE1. Fixes part of bug 40400; bugfix
          on 0.1.1.13-alpha.
        - Do not log "circuit_receive_relay_cell failed" at
          LOG_PROTOCOL_WARN; instead log it at DEBUG. In every case where we
          would want to log this as a protocol warning, we are already
          logging another warning from inside circuit_receive_relay_cell.
          Fixes part of bug 40400; bugfix on 0.1.1.9-alpha.
    
      o Code simplification and refactoring:
        - Lower the official maximum for "guard-extreme-restriction-percent"
          to 100. This has no effect on when the guard code will generate a
          warning, but it makes the intent of the option clearer. Fixes bug
          40486; bugfix on 0.3.0.1-alpha.
    
      o Documentation:
        - Add links to original tor design paper and anonbib to
          docs/HACKING/README.1st.md. Closes ticket 33742. Patch from
          Emily Bones.
        - Describe the "fingerprint-ed25519" file in the tor.1 man page.
          Fixes bug 40467; bugfix on 0.4.3.1-alpha. Patch by Neel Chauhan.
        - Provide an improved version of the tor-exit-notice.html file for
          exit relays to use as a landing page. The text is unchanged, but
          the page design and layout are significantly modernized, and
          several links are fixed. Patch from "n_user"; closes ticket 40529.
    
      o Testing:
        - Add unit tests for the Linux seccomp sandbox. Resolves
          issue 16803.
    
      o Code simplification and refactoring (rust):
        - Remove Rust support and its associated code. It is unsupported and
          Rust focus should be shifted to arti. Closes ticket 40469.
    
      o Documentation (man, relay):
        - Missing "OverloadStatistics" in tor.1 manpage. Fixes bug 40504;
          bugfix on 0.4.6.1-alpha.
    
      o Testing (CI, chutney):
        - Bump the data size that chutney transmits to 5MBytes in order to
          trigger the flow control and congestion window code. Closes
          ticket 40485.
    
    
    Changes in version 0.4.6.10 - 2022-02-04
      This version contains minor bugfixes but one in particular is that relays
      don't advertise onion service v2 support at the protocol version level.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on February 04, 2022.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2022/02/04.
    
      o Minor bugfix (logging):
        - Update a log notice dead URL to a working one. Fixes bug 40544;
          bugfix on 0.3.5.1-alpha.
    
      o Minor bugfix (relay):
        - Remove the HSDir and HSIntro onion service v2 protocol versions so
          relay stop advertising that they support them. Fixes bug 40509;
          bugfix on 0.3.5.17.
    
      o Minor bugfixes (MetricsPort, Prometheus):
        - Add double quotes to the label values of the onion service
          metrics. Fixes bug 40552; bugfix on 0.4.5.1-alpha.
    
    
    Changes in version 0.4.6.9 - 2021-12-15
      This version fixes several bugs from earlier versions of Tor. One important
      piece is the removal of DNS timeout metric from the overload general signal.
      See below for more details.
    
      o Major bugfixes (relay, overload):
        - Don't make Tor DNS timeout trigger an overload general state.
          These timeouts are different from DNS server timeout. They have to
          be seen as timeout related to UX and not because of a network
          problem. Fixes bug 40527; bugfix on 0.4.6.1-alpha.
    
      o Minor feature (reproducible build):
        - The repository can now build reproducible tarballs which adds the
          build command "make dist-reprod" for that purpose. Closes
          ticket 26299.
    
      o Minor features (compilation):
        - Give an error message if trying to build with a version of
          LibreSSL known not to work with Tor. (There's an incompatibility
          with LibreSSL versions 3.2.1 through 3.4.0 inclusive because of
          their incompatibility with OpenSSL 1.1.1's TLSv1.3 APIs.) Closes
          ticket 40511.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories generated on December 15, 2021.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2021/12/15.
    
      o Minor bugfixes (compilation):
        - Fix our configuration logic to detect whether we had OpenSSL 3:
          previously, our logic was reversed. This has no other effect than
          to change whether we suppress deprecated API warnings. Fixes bug
          40429; bugfix on 0.3.5.13.
    
      o Minor bugfixes (relay):
        - Reject IPv6-only DirPorts. Our reachability self-test forces
          DirPorts to be IPv4, but our configuration parser allowed them to
          be IPv6-only, which led to an assertion failure. Fixes bug 40494;
          bugfix on 0.4.5.1-alpha.
    
      o Documentation (man, relay):
        - Missing "OverloadStatistics" in tor.1 manpage. Fixes bug 40504;
          bugfix on 0.4.6.1-alpha.
    
    
    Changes in version 0.4.6.8 - 2021-10-26
      This version fixes several bugs from earlier versions of Tor. One
      highlight is a fix on how we track DNS timeouts to report general
      relay overload.
    
      o Major bugfixes (relay, overload state):
        - Relays report the general overload state for DNS timeout errors
          only if X% of all DNS queries over Y seconds are errors. Before
          that, it only took 1 timeout to report the overload state which
          was just too low of a threshold. The X and Y values are 1% and 10
          minutes respectively but they are also controlled by consensus
          parameters. Fixes bug 40491; bugfix on 0.4.6.1-alpha.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories for October 2021. Closes
          ticket 40493.
    
      o Minor features (testing):
        - On a testing network, relays can now use the
          TestingMinTimeToReportBandwidth option to change the smallest
          amount of time over which they're willing to report their observed
          maximum bandwidth. Previously, this was fixed at 1 day. For
          safety, values under 2 hours are only supported on testing
          networks. Part of a fix for ticket 40337.
        - Relays on testing networks no longer rate-limit how frequently
          they are willing to report new bandwidth measurements. Part of a
          fix for ticket 40337.
        - Relays on testing networks now report their observed bandwidths
          immediately from startup. Previously, they waited until they had
          been running for a full day. Closes ticket 40337.
    
      o Minor bugfix (onion service):
        - Do not flag an HSDir as non-running in case the descriptor upload
          or fetch fails. An onion service closes pending directory
          connections before uploading a new descriptor which can thus lead
          to wrongly flagging many relays and thus affecting circuit building
          path selection. Fixes bug 40434; bugfix on 0.2.0.13-alpha.
        - Improve logging when a bad HS version is given. Fixes bug 40476;
          bugfix on 0.4.6.1-alpha.
    
      o Minor bugfix (CI, onion service):
        - Exclude onion service version 2 Stem tests in our CI. Fixes bug 40500;
          bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (compatibility):
        - Fix compatibility with the most recent Libevent versions, which no
          longer have an evdns_set_random_bytes() function. Because this
          function has been a no-op since Libevent 2.0.4-alpha, it is safe
          for us to just stop calling it. Fixes bug 40371; bugfix
          on 0.2.1.7-alpha.
    
      o Minor bugfixes (onion service, TROVE-2021-008):
        - Only log v2 access attempts once total, in order to not pollute
          the logs with warnings and to avoid recording the times on disk
          when v2 access was attempted. Note that the onion address was
          _never_ logged. This counts as a Low-severity security issue.
          Fixes bug 40474; bugfix on 0.4.5.8.
    
    
    Changes in version 0.4.5.11 - 2021-10-26
      The major change in this version is that v2 onion services are now
      disabled at the client, service, and relay: any Tor nodes running this
      version and onward will stop supporting v2 onion services. This is the
      last step in the long deprecation process of v2 onion services.
      Everyone running an earlier version, whether as a client, a relay, or
      an onion service, should upgrade to Tor 0.3.5.17, 0.4.5.11,
      or 0.4.6.8.
    
      o Major feature (onion service v2):
        - See https://blog.torproject.org/v2-deprecation-timeline for
          details on how to transition from v2 to v3.
        - The control port commands HSFETCH and HSPOST no longer allow
          version 2, and it is no longer possible to create a v2 service
          with ADD_ONION.
        - Tor no longer allows creating v2 services, or connecting as a
          client to a v2 service. Relays will decline to be a v2 HSDir or
          introduction point. This effectively disables onion service
          version 2 Tor-wide. Closes ticket 40476.
    
      o Minor features (bridge, backport from 0.4.6.8):
        - We now announce the URL to Tor's new bridge status at
          https://bridges.torproject.org/ when Tor is configured to run as a
          bridge relay. Closes ticket 30477.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories for October 2021. Closes
          ticket 40493.
    
      o Minor features (logging, diagnostic, backport from 0.4.6.5):
        - Log decompression failures at a higher severity level, since they
          can help provide missing context for other warning messages. We
          rate-limit these messages, to avoid flooding the logs if they
          begin to occur frequently. Closes ticket 40175.
    
      o Minor features (testing, backport from 0.4.6.8):
        - On a testing network, relays can now use the
          TestingMinTimeToReportBandwidth option to change the smallest
          amount of time over which they're willing to report their observed
          maximum bandwidth. Previously, this was fixed at 1 day. For
          safety, values under 2 hours are only supported on testing
          networks. Part of a fix for ticket 40337.
        - Relays on testing networks no longer rate-limit how frequently
          they are willing to report new bandwidth measurements. Part of a
          fix for ticket 40337.
        - Relays on testing networks now report their observed bandwidths
          immediately from startup. Previously, they waited until they had
          been running for a full day. Closes ticket 40337.
    
      o Minor bugfix (CI, onion service):
        - Exclude onion service version 2 Stem tests in our CI. Fixes bug 40500;
          bugfix on 0.3.2.1-alpha.
    
      o Minor bugfix (onion service, backport from 0.4.6.8):
        - Do not flag an HSDir as non-running in case the descriptor upload
          or fetch fails. An onion service closes pending directory
          connections before uploading a new descriptor which can thus lead
          to wrongly flagging many relays and thus affecting circuit building
          path selection. Fixes bug 40434; bugfix on 0.2.0.13-alpha.
    
      o Minor bugfixes (compatibility, backport from 0.4.6.8):
        - Fix compatibility with the most recent Libevent versions, which no
          longer have an evdns_set_random_bytes() function. Because this
          function has been a no-op since Libevent 2.0.4-alpha, it is safe
          for us to just stop calling it. Fixes bug 40371; bugfix
          on 0.2.1.7-alpha.
    
      o Minor bugfixes (consensus handling, backport from 0.4.6.4-rc):
        - Avoid a set of bugs that could be caused by inconsistently
          preferring an out-of-date consensus stored in a stale directory
          cache over a more recent one stored on disk as the latest
          consensus. Fixes bug 40375; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (onion service, TROVE-2021-008, backport from 0.4.6.8):
        - Only log v2 access attempts once total, in order to not pollute
          the logs with warnings and to avoid recording the times on disk
          when v2 access was attempted. Note that the onion address was
          _never_ logged. This counts as a Low-severity security issue.
          Fixes bug 40474; bugfix on 0.4.5.8.
    
    
    Changes in version 0.3.5.17 - 2021-10-26
      The major change in this version is that v2 onion services are now
      disabled at the client, service, and relay: any Tor nodes running this
      version and onward will stop supporting v2 onion services. This is the
      last step in the long deprecation process of v2 onion services.
      Everyone running an earlier version, whether as a client, a relay, or
      an onion service, should upgrade to Tor 0.3.5.17, 0.4.5.11,
      or 0.4.6.8.
    
      o Major feature (onion service v2, backport from 0.4.5.11):
        - See https://blog.torproject.org/v2-deprecation-timeline for
          details on how to transition from v2 to v3.
        - The control port commands HSFETCH and HSPOST no longer allow
          version 2, and it is no longer possible to create a v2 service
          with ADD_ONION.
        - Tor no longer allows creating v2 services, or connecting as a
          client to a v2 service. Relays will decline to be a v2 HSDir or
          introduction point. This effectively disables onion service
          version 2 Tor-wide. Closes ticket 40476.
    
      o Minor features (bridge, backport from 0.4.6.8):
        - We now announce the URL to Tor's new bridge status at
          https://bridges.torproject.org/ when Tor is configured to run as a
          bridge relay. Closes ticket 30477.
    
      o Minor features (fallbackdir):
        - Regenerate fallback directories for October 2021. Closes
          ticket 40493.
    
      o Minor bugfixes (compatibility, backport from 0.4.6.8):
        - Fix compatibility with the most recent Libevent versions, which no
          longer have an evdns_set_random_bytes() function. Because this
          function has been a no-op since Libevent 2.0.4-alpha, it is safe
          for us to just stop calling it. Fixes bug 40371; bugfix
          on 0.2.1.7-alpha.
    
    
    Changes in version 0.4.6.7 - 2021-08-16
      This version fixes several bugs from earlier versions of Tor, including one
      that could lead to a denial-of-service attack. Everyone running an earlier
      version, whether as a client, a relay, or an onion service, should upgrade
      to Tor 0.3.5.16, 0.4.5.10, or 0.4.6.7.
    
      o Major bugfixes (cryptography, security):
        - Resolve an assertion failure caused by a behavior mismatch between our
          batch-signature verification code and our single-signature verification
          code. This assertion failure could be triggered remotely, leading to a
          denial of service attack. We fix this issue by disabling batch
          verification. Fixes bug 40078; bugfix on 0.2.6.1-alpha. This issue is
          also tracked as TROVE-2021-007 and CVE-2021-38385. Found by Henry de
          Valence.
    
      o Minor feature (fallbackdir):
        - Regenerate fallback directories list. Close ticket 40447.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database,
          as retrieved on 2021/08/12.
    
      o Minor bugfix (crypto):
        - Disable the unused batch verification feature of ed25519-donna. Fixes
          bug 40078; bugfix on 0.2.6.1-alpha. Found by Henry de Valence.
    
      o Minor bugfixes (onion service):
        - Send back the extended SOCKS error 0xF6 (Onion Service Invalid Address)
          for a v2 onion address. Fixes bug 40421; bugfix on 0.4.6.2-alpha.
    
      o Minor bugfix (CI, onion service):
        - Exclude onion service version 2 Stem tests in our CI. Fixes bug 40500;
          bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (relay):
        - Reduce the compression level for data streaming from HIGH to LOW in
          order to reduce CPU load on the directory relays. Fixes bug 40301;
          bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (timekeeping):
        - Calculate the time of day correctly on systems where the time_t
          type includes leap seconds. (This is not the case on most
          operating systems, but on those where it occurs, our tor_timegm
          function did not correctly invert the system's gmtime function,
          which could result in assertion failures when calculating
          voting schedules.)  Fixes bug 40383; bugfix on 0.2.0.3-alpha.
    
    
    Changes in version 0.4.5.10 - 2021-08-16
      This version fixes several bugs from earlier versions of Tor, including one
      that could lead to a denial-of-service attack. Everyone running an earlier
      version, whether as a client, a relay, or an onion service, should upgrade
      to Tor 0.3.5.16, 0.4.5.10, or 0.4.6.7.
    
      o Major bugfixes (cryptography, security):
        - Resolve an assertion failure caused by a behavior mismatch between our
          batch-signature verification code and our single-signature verification
          code. This assertion failure could be triggered remotely, leading to a
          denial of service attack. We fix this issue by disabling batch
          verification. Fixes bug 40078; bugfix on 0.2.6.1-alpha. This issue is
          also tracked as TROVE-2021-007 and CVE-2021-38385. Found by Henry de
          Valence.
    
      o Minor feature (fallbackdir):
        - Regenerate fallback directories list. Close ticket 40447.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database,
          as retrieved on 2021/08/12.
    
      o Minor features (testing):
        - Enable the deterministic RNG for unit tests that covers the address set
          bloomfilter-based API's. Fixes bug 40419; bugfix on 0.3.3.2-alpha.
    
      o Minor bugfix (crypto):
        - Disable the unused batch verification feature of ed25519-donna. Fixes
          bug 40078; bugfix on 0.2.6.1-alpha. Found by Henry de Valence.
    
      o Minor bugfixes (relay, backport from 0.4.6.x):
        - Reduce the compression level for data streaming from HIGH to LOW. Fixes
          bug 40301; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (timekeeping, backport from 0.4.6.x):
        - Calculate the time of day correctly on systems where the time_t
          type includes leap seconds. (This is not the case on most
          operating systems, but on those where it occurs, our tor_timegm
          function did not correctly invert the system's gmtime function,
          which could result in assertion failures when calculating
          voting schedules.)  Fixes bug 40383; bugfix on 0.2.0.3-alpha.
    
      o Minor bugfixes (warnings, portability, backport from 0.4.6.x):
        - Suppress a strict-prototype warning when building with some versions
          of NSS.  Fixes bug 40409; bugfix on 0.3.5.1-alpha.
    
    
    Changes in version 0.3.5.16 - 2021-08-16
      This version fixes several bugs from earlier versions of Tor, including one
      that could lead to a denial-of-service attack. Everyone running an earlier
      version, whether as a client, a relay, or an onion service, should upgrade
      to Tor 0.3.5.16, 0.4.5.10, or 0.4.6.7.
    
      o Major bugfixes (cryptography, security):
        - Resolve an assertion failure caused by a behavior mismatch between our
          batch-signature verification code and our single-signature verification
          code. This assertion failure could be triggered remotely, leading to a
          denial of service attack. We fix this issue by disabling batch
          verification. Fixes bug 40078; bugfix on 0.2.6.1-alpha. This issue is
          also tracked as TROVE-2021-007 and CVE-2021-38385. Found by Henry de
          Valence.
    
      o Minor feature (fallbackdir):
        - Regenerate fallback directories list. Close ticket 40447.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database,
          as retrieved on 2021/08/12.
    
      o Minor bugfix (crypto):
        - Disable the unused batch verification feature of ed25519-donna. Fixes
          bug 40078; bugfix on 0.2.6.1-alpha. Found by Henry de Valence.
    
      o Minor bugfixes (relay, backport from 0.4.6.x):
        - Reduce the compression level for data streaming from HIGH to LOW. Fixes
          bug 40301; bugfix on 0.3.5.1-alpha.
    
    
    Changes in version 0.4.6.6 - 2021-06-30
      Tor 0.4.6.6 makes several small fixes on 0.4.6.5, including one that
      allows Tor to build correctly on older versions of GCC. You should
      upgrade to this version if you were having trouble building Tor
      0.4.6.5; otherwise, there is probably no need.
    
      o Minor bugfixes (compilation):
        - Fix a compilation error when trying to build Tor with a compiler
          that does not support const variables in static initializers.
          Fixes bug 40410; bugfix on 0.4.6.5.
        - Suppress a strict-prototype warning when building with some
          versions of NSS. Fixes bug 40409; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (testing):
        - Enable the deterministic RNG for unit tests that covers the
          address set bloomfilter-based API's. Fixes bug 40419; bugfix
          on 0.3.3.2-alpha.
    
    
    Changes in version 0.4.6.5 - 2021-06-14
      Tor 0.4.6.5 is the first stable release in its series. The 0.4.6.x
      series includes numerous features and bugfixes, including a significant
      improvement to our circuit timeout algorithm that should improve
      observed client performance, and a way for relays to report when they are
      overloaded.
    
      This release also includes security fixes for several security issues,
      including a denial-of-service attack against onion service clients,
      and another denial-of-service attack against relays. Everybody should
      upgrade to one of 0.3.5.15, 0.4.4.9, 0.4.5.9, or 0.4.6.5.
    
      Below are the changes since 0.4.5.8. For a list of changes since
      0.4.6.4-rc, see the ChangeLog file.
    
      o Major bugfixes (security):
        - Don't allow relays to spoof RELAY_END or RELAY_RESOLVED cell on
          half-closed streams. Previously, clients failed to validate which
          hop sent these cells: this would allow a relay on a circuit to end
          a stream that wasn't actually built with it. Fixes bug 40389;
          bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2021-
          003 and CVE-2021-34548.
    
      o Major bugfixes (security, defense-in-depth):
        - Detect more failure conditions from the OpenSSL RNG code.
          Previously, we would detect errors from a missing RNG
          implementation, but not failures from the RNG code itself.
          Fortunately, it appears those failures do not happen in practice
          when Tor is using OpenSSL's default RNG implementation. Fixes bug
          40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as
          TROVE-2021-004. Reported by Jann Horn at Google's Project Zero.
    
      o Major bugfixes (security, denial of service):
        - Resist a hashtable-based CPU denial-of-service attack against
          relays. Previously we used a naive unkeyed hash function to look
          up circuits in a circuitmux object. An attacker could exploit this
          to construct circuits with chosen circuit IDs, to create
          collisions and make the hash table inefficient. Now we use a
          SipHash construction here instead. Fixes bug 40391; bugfix on
          0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005 and
          CVE-2021-34549. Reported by Jann Horn from Google's Project Zero.
        - Fix an out-of-bounds memory access in v3 onion service descriptor
          parsing. An attacker could exploit this bug by crafting an onion
          service descriptor that would crash any client that tried to visit
          it. Fixes bug 40392; bugfix on 0.3.0.1-alpha. This issue is also
          tracked as TROVE-2021-006 and CVE-2021-34550. Reported by Sergei
          Glazunov from Google's Project Zero.
    
      o Major features (control port, onion services):
        - Add controller support for creating version 3 onion services with
          client authorization. Previously, only v2 onion services could be
          created with client authorization. Closes ticket 40084. Patch by
          Neel Chauhan.
    
      o Major features (directory authority):
        - When voting on a relay with a Sybil-like appearance, add the Sybil
          flag when clearing out the other flags. This lets a relay operator
          know why their relay hasn't been included in the consensus. Closes
          ticket 40255. Patch by Neel Chauhan.
    
      o Major features (metrics):
        - Relays now report how overloaded they are in their extrainfo
          documents. This information is controlled with the
          OverloadStatistics torrc option, and it will be used to improve
          decisions about the network's load balancing. Implements proposal
          328; closes ticket 40222.
    
      o Major features (relay, denial of service):
        - Add a new DoS subsystem feature to control the rate of client
          connections for relays. Closes ticket 40253.
    
      o Major features (statistics):
        - Relays now publish statistics about the number of v3 onion
          services and volume of v3 onion service traffic, in the same
          manner they already do for v2 onions. Closes ticket 23126.
    
      o Major bugfixes (circuit build timeout):
        - Improve the accuracy of our circuit build timeout calculation for
          60%, 70%, and 80% build rates for various guard choices. We now
          use a maximum likelihood estimator for Pareto parameters of the
          circuit build time distribution, instead of a "right-censored
          estimator". This causes clients to ignore circuits that never
          finish building in their timeout calculations. Previously, clients
          were counting such unfinished circuits as having the highest
          possible build time value, when in reality these circuits most
          likely just contain relays that are offline. We also now wait a
          bit longer to let circuits complete for measurement purposes,
          lower the minimum possible effective timeout from 1.5 seconds to
          10ms, and increase the resolution of the circuit build time
          histogram from 50ms bin widths to 10ms bin widths. Additionally,
          we alter our estimate Xm by taking the maximum of the top 10 most
          common build time values of the 10ms histogram, and compute Xm as
          the average of these. Fixes bug 40168; bugfix on 0.2.2.14-alpha.
        - Remove max_time calculation and associated warning from circuit
          build timeout 'alpha' parameter estimation, as this is no longer
          needed by our new estimator from 40168. Fixes bug 34088; bugfix
          on 0.2.2.9-alpha.
    
      o Major bugfixes (signing key):
        - In the tor-gencert utility, give an informative error message if
          the passphrase given in `--create-identity-key` is too short.
          Fixes bug 40189; bugfix on 0.2.0.1-alpha. Patch by Neel Chauhan.
    
      o Minor features (bridge):
        - We now announce the URL to Tor's new bridge status at
          https://bridges.torproject.org/ when Tor is configured to run as a
          bridge relay. Closes ticket 30477.
    
      o Minor features (build system):
        - New "make lsp" command to auto generate the compile_commands.json
          file used by the ccls server. The "bear" program is needed for
          this. Closes ticket 40227.
    
      o Minor features (client):
        - Clients now check whether their streams are attempting to re-enter
          the Tor network (i.e. to send Tor traffic over Tor), and close
          them preemptively if they think exit relays will refuse them for
          this reason. See ticket 2667 for details. Closes ticket 40271.
    
      o Minor features (command line):
        - Add long format name "--torrc-file" equivalent to the existing
          command-line option "-f". Closes ticket 40324. Patch by
          Daniel Pinto.
    
      o Minor features (command-line interface):
        - Add build informations to `tor --version` in order to ease
          reproducible builds. Closes ticket 32102.
        - When parsing command-line flags that take an optional argument,
          treat the argument as absent if it would start with a '-'
          character. Arguments in that form are not intelligible for any of
          our optional-argument flags. Closes ticket 40223.
        - Allow a relay operator to list the ed25519 keys on the command
          line by adding the `rsa` and `ed25519` arguments to the
          --list-fingerprint flag to show the respective RSA and ed25519
          relay fingerprint. Closes ticket 33632. Patch by Neel Chauhan.
    
      o Minor features (compatibility):
        - Remove an assertion function related to TLS renegotiation. It was
          used nowhere outside the unit tests, and it was breaking
          compilation with recent alpha releases of OpenSSL 3.0.0. Closes
          ticket 40399.
    
      o Minor features (control port, stream handling):
        - Add the stream ID to the event line in the ADDRMAP control event.
          Closes ticket 40249. Patch by Neel Chauhan.
    
      o Minor features (dormant mode):
        - Add a new 'DormantTimeoutEnabled' option to allow coarse-grained
          control over whether the client ever becomes dormant from
          inactivity. Most people won't need this. Closes ticket 40228.
        - Add a new 'DormantTimeoutEnabled' option for coarse-grained
          control over whether the client can become dormant from
          inactivity. Most people won't need this. Closes ticket 40228.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2021/06/10.
    
      o Minor features (logging):
        - Edit heartbeat log messages so that more of them begin with the
          string "Heartbeat: ". Closes ticket 40322; patch
          from 'cypherpunks'.
        - Change the DoS subsystem heartbeat line format to be more clear on
          what has been detected/rejected, and which option is disabled (if
          any). Closes ticket 40308.
        - In src/core/mainloop/mainloop.c and src/core/mainloop/connection.c,
          put brackets around IPv6 addresses in log messages. Closes ticket
          40232. Patch by Neel Chauhan.
    
      o Minor features (logging, diagnostic):
        - Log decompression failures at a higher severity level, since they
          can help provide missing context for other warning messages. We
          rate-limit these messages, to avoid flooding the logs if they
          begin to occur frequently. Closes ticket 40175.
    
      o Minor features (onion services):
        - Add a warning message when trying to connect to (no longer
          supported) v2 onion services. Closes ticket 40373.
    
      o Minor features (performance, windows):
        - Use SRWLocks to implement locking on Windows. Replaces the
          "critical section" locking implementation with the faster
          SRWLocks, available since Windows Vista. Closes ticket 17927.
          Patch by Daniel Pinto.
    
      o Minor features (protocol, proxy support, defense in depth):
        - Close HAProxy connections if they somehow manage to send us data
          before we start reading. Closes another case of ticket 40017.
    
      o Minor features (tests, portability):
        - Port the hs_build_address.py test script to work with recent
          versions of python. Closes ticket 40213. Patch from
          Samanta Navarro.
    
      o Minor features (vote document):
        - Add a "stats" line to directory authority votes, to report various
          statistics that authorities compute about the relays. This will
          help us diagnose the network better. Closes ticket 40314.
    
      o Minor bugfixes (build):
        - The configure script now shows whether or not lzma and zstd have
          been used, not just if the enable flag was passed in. Fixes bug
          40236; bugfix on 0.4.3.1-alpha.
    
      o Minor bugfixes (compatibility):
        - Fix a failure in the test cases when running on the "hppa"
          architecture, along with a related test that might fail on other
          architectures in the future. Fixes bug 40274; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (compilation):
        - Fix a compilation warning about unused functions when building
          with a libc that lacks the GLOB_ALTDIRFUNC constant. Fixes bug
          40354; bugfix on 0.4.5.1-alpha. Patch by Daniel Pinto.
    
      o Minor bugfixes (consensus handling):
        - Avoid a set of bugs that could be caused by inconsistently
          preferring an out-of-date consensus stored in a stale directory
          cache over a more recent one stored on disk as the latest
          consensus. Fixes bug 40375; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (control, sandbox):
        - Allow the control command SAVECONF to succeed when the seccomp
          sandbox is enabled, and make SAVECONF keep only one backup file to
          simplify implementation. Previously SAVECONF allowed a large
          number of backup files, which made it incompatible with the
          sandbox. Fixes bug 40317; bugfix on 0.2.5.4-alpha. Patch by
          Daniel Pinto.
    
      o Minor bugfixes (directory authorities, voting):
        - Add a new consensus method (31) to support any future changes that
          authorities decide to make to the value of bwweightscale or
          maxunmeasuredbw. Previously, there was a bug that prevented the
          authorities from parsing these consensus parameters correctly under
          most circumstances. Fixes bug 19011; bugfix on 0.2.2.10-alpha.
    
      o Minor bugfixes (ipv6):
        - Allow non-SOCKSPorts to disable IPv4, IPv6, and PreferIPv4. Some
          rare configurations might break, but in this case you can disable
          NoIPv4Traffic and NoIPv6Traffic as needed. Fixes bug 33607; bugfix
          on 0.4.1.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (key generation):
        - Do not require a valid torrc when using the `--keygen` argument to
          generate a signing key. This allows us to generate keys on systems
          or users which may not run Tor. Fixes bug 40235; bugfix on
          0.2.7.2-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (logging, relay):
        - Emit a warning if an Address is found to be internal and tor can't
          use it. Fixes bug 40290; bugfix on 0.4.5.1-alpha.
    
      o Minor bugfixes (metrics port):
        - Fix a bug that made tor try to re-bind() on an already open
          MetricsPort every 60 seconds. Fixes bug 40370; bugfix
          on 0.4.5.1-alpha.
    
      o Minor bugfixes (onion services, logging):
        - Downgrade the severity of a few rendezvous circuit-related
          warnings from warning to info. Fixes bug 40207; bugfix on
          0.3.2.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (relay):
        - Reduce the compression level for data streaming from HIGH to LOW.
          This should reduce the CPU and memory burden for directory caches.
          Fixes bug 40301; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (testing, BSD):
        - Fix pattern-matching errors when patterns expand to invalid paths
          on BSD systems. Fixes bug 40318; bugfix on 0.4.5.1-alpha. Patch by
          Daniel Pinto.
    
      o Code simplification and refactoring:
        - Remove the orconn_ext_or_id_map structure and related functions.
          (Nothing outside of unit tests used them.) Closes ticket 33383.
          Patch by Neel Chauhan.
    
      o Removed features:
        - Remove unneeded code for parsing private keys in directory
          documents. This code was only used for client authentication in v2
          onion services, which are now unsupported. Closes ticket 40374.
        - As of this release, Tor no longer supports the old v2 onion
          services. They were deprecated last July for security, and support
          will be removed entirely later this year. We strongly encourage
          everybody to migrate to v3 onion services. For more information,
          see https://blog.torproject.org/v2-deprecation-timeline . Closes
          ticket 40266. (NOTE: We accidentally released an earlier version
          of the 0.4.6.1-alpha changelog without this entry. Sorry for
          the confusion!)
    
      o Code simplification and refactoring (metrics, DoS):
        - Move the DoS subsystem into the subsys manager, including its
          configuration options. Closes ticket 40261.
    
      o Documentation (manual):
        - Move the ServerTransport* options to the "SERVER OPTIONS" section.
          Closes issue 40331.
        - Indicate that the HiddenServiceStatistics option also applies to
          bridges. Closes ticket 40346.
        - Move the description of BridgeRecordUsageByCountry to the section
          "STATISTICS OPTIONS". Closes ticket 40323.
    
      o Removed features (relay):
        - Because DirPorts are only used on authorities, relays no longer
          advertise them. Similarly, self-testing for DirPorts has been
          disabled, since an unreachable DirPort is no reason for a relay
          not to advertise itself. (Configuring a DirPort will still work,
          for now.) Closes ticket 40282.
    
    
    Changes in version 0.4.5.9 - 2021-06-14
      Tor 0.4.5.9 fixes several security issues, including a
      denial-of-service attack against onion service clients, and another
      denial-of-service attack against relays. Everybody should upgrade to
      one of 0.3.5.15, 0.4.4.9, 0.4.5.9, or 0.4.6.5.
    
      o Major bugfixes (security, backport from 0.4.6.5):
        - Don't allow relays to spoof RELAY_END or RELAY_RESOLVED cell on
          half-closed streams. Previously, clients failed to validate which
          hop sent these cells: this would allow a relay on a circuit to end
          a stream that wasn't actually built with it. Fixes bug 40389;
          bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2021-
          003 and CVE-2021-34548.
    
      o Major bugfixes (security, defense-in-depth, backport from 0.4.6.5):
        - Detect more failure conditions from the OpenSSL RNG code.
          Previously, we would detect errors from a missing RNG
          implementation, but not failures from the RNG code itself.
          Fortunately, it appears those failures do not happen in practice
          when Tor is using OpenSSL's default RNG implementation. Fixes bug
          40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as
          TROVE-2021-004. Reported by Jann Horn at Google's Project Zero.
    
      o Major bugfixes (security, denial of service, backport from 0.4.6.5):
        - Resist a hashtable-based CPU denial-of-service attack against
          relays. Previously we used a naive unkeyed hash function to look
          up circuits in a circuitmux object. An attacker could exploit this
          to construct circuits with chosen circuit IDs, to create
          collisions and make the hash table inefficient. Now we use a
          SipHash construction here instead. Fixes bug 40391; bugfix on
          0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005 and
          CVE-2021-34549. Reported by Jann Horn from Google's Project Zero.
        - Fix an out-of-bounds memory access in v3 onion service descriptor
          parsing. An attacker could exploit this bug by crafting an onion
          service descriptor that would crash any client that tried to visit
          it. Fixes bug 40392; bugfix on 0.3.0.1-alpha. This issue is also
          tracked as TROVE-2021-006 and CVE-2021-34550. Reported by Sergei
          Glazunov from Google's Project Zero.
    
      o Minor features (compatibility, backport from 0.4.6.4-rc):
        - Remove an assertion function related to TLS renegotiation. It was
          used nowhere outside the unit tests, and it was breaking
          compilation with recent alpha releases of OpenSSL 3.0.0. Closes
          ticket 40399.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2021/06/10.
    
      o Minor bugfixes (control, sandbox, backport from 0.4.6.4-rc):
        - Allow the control command SAVECONF to succeed when the seccomp
          sandbox is enabled, and make SAVECONF keep only one backup file to
          simplify implementation. Previously SAVECONF allowed a large
          number of backup files, which made it incompatible with the
          sandbox. Fixes bug 40317; bugfix on 0.2.5.4-alpha. Patch by
          Daniel Pinto.
    
      o Minor bugfixes (metrics port, backport from 0.4.6.4-rc):
        - Fix a bug that made tor try to re-bind() on an already open
          MetricsPort every 60 seconds. Fixes bug 40370; bugfix
          on 0.4.5.1-alpha.
    
    
    Changes in version 0.4.4.9 - 2021-06-14
      Tor 0.4.4.9 fixes several security issues, including a
      denial-of-service attack against onion service clients, and another
      denial-of-service attack against relays. Everybody should upgrade to
      one of 0.3.5.15, 0.4.4.9, 0.4.5.9, or 0.4.6.5.
    
      Note that the scheduled end-of-life date for the Tor 0.4.4.x series is
      June 15. This is therefore the last release in its series. Everybody
      still running 0.4.4.x should plan to upgrade to 0.4.5.x or later.
    
      o Major bugfixes (security, backport from 0.4.6.5):
        - Don't allow relays to spoof RELAY_END or RELAY_RESOLVED cell on
          half-closed streams. Previously, clients failed to validate which
          hop sent these cells: this would allow a relay on a circuit to end
          a stream that wasn't actually built with it. Fixes bug 40389;
          bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2021-
          003 and CVE-2021-34548.
    
      o Major bugfixes (security, defense-in-depth, backport from 0.4.6.5):
        - Detect more failure conditions from the OpenSSL RNG code.
          Previously, we would detect errors from a missing RNG
          implementation, but not failures from the RNG code itself.
          Fortunately, it appears those failures do not happen in practice
          when Tor is using OpenSSL's default RNG implementation. Fixes bug
          40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as
          TROVE-2021-004. Reported by Jann Horn at Google's Project Zero.
    
      o Major bugfixes (security, denial of service, backport from 0.4.6.5):
        - Resist a hashtable-based CPU denial-of-service attack against
          relays. Previously we used a naive unkeyed hash function to look
          up circuits in a circuitmux object. An attacker could exploit this
          to construct circuits with chosen circuit IDs, to create
          collisions and make the hash table inefficient. Now we use a
          SipHash construction here instead. Fixes bug 40391; bugfix on
          0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005 and
          CVE-2021-34549. Reported by Jann Horn from Google's Project Zero.
        - Fix an out-of-bounds memory access in v3 onion service descriptor
          parsing. An attacker could exploit this bug by crafting an onion
          service descriptor that would crash any client that tried to visit
          it. Fixes bug 40392; bugfix on 0.3.0.1-alpha. This issue is also
          tracked as TROVE-2021-006 and CVE-2021-34550. Reported by Sergei
          Glazunov from Google's Project Zero.
    
      o Minor features (compatibility, backport from 0.4.6.4-rc):
        - Remove an assertion function related to TLS renegotiation. It was
          used nowhere outside the unit tests, and it was breaking
          compilation with recent alpha releases of OpenSSL 3.0.0. Closes
          ticket 40399.
    
      o Minor features (fallback directory list, backport from 0.4.6.2-alpha):
        - Regenerate the list of fallback directories to contain a new set
          of 200 relays. Closes ticket 40265.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2021/06/10.
    
      o Minor bugfixes (channel, DoS, backport from 0.4.6.2-alpha):
        - Fix a non-fatal BUG() message due to a too-early free of a string,
          when listing a client connection from the DoS defenses subsystem.
          Fixes bug 40345; bugfix on 0.4.3.4-rc.
    
      o Minor bugfixes (compiler warnings, backport from 0.4.6.3-rc):
        - Fix an indentation problem that led to a warning from GCC 11.1.1.
          Fixes bug 40380; bugfix on 0.3.0.1-alpha.
    
    
    Changes in version 0.3.5.15 - 2021-06-14
      Tor 0.3.5.15 fixes several security issues, including a
      denial-of-service attack against onion service clients, and another
      denial-of-service attack against relays. Everybody should upgrade to
      one of 0.3.5.15, 0.4.4.9, 0.4.5.9, or 0.4.6.5.
    
      o Major bugfixes (security, backport from 0.4.6.5):
        - Don't allow relays to spoof RELAY_END or RELAY_RESOLVED cell on
          half-closed streams. Previously, clients failed to validate which
          hop sent these cells: this would allow a relay on a circuit to end
          a stream that wasn't actually built with it. Fixes bug 40389;
          bugfix on 0.3.5.1-alpha. This issue is also tracked as TROVE-2021-
          003 and CVE-2021-34548.
    
      o Major bugfixes (security, defense-in-depth, backport from 0.4.6.5):
        - Detect more failure conditions from the OpenSSL RNG code.
          Previously, we would detect errors from a missing RNG
          implementation, but not failures from the RNG code itself.
          Fortunately, it appears those failures do not happen in practice
          when Tor is using OpenSSL's default RNG implementation. Fixes bug
          40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as
          TROVE-2021-004. Reported by Jann Horn at Google's Project Zero.
    
      o Major bugfixes (security, denial of service, backport from 0.4.6.5):
        - Resist a hashtable-based CPU denial-of-service attack against
          relays. Previously we used a naive unkeyed hash function to look
          up circuits in a circuitmux object. An attacker could exploit this
          to construct circuits with chosen circuit IDs, to create
          collisions and make the hash table inefficient. Now we use a
          SipHash construction here instead. Fixes bug 40391; bugfix on
          0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005 and
          CVE-2021-34549. Reported by Jann Horn from Google's Project Zero.
        - Fix an out-of-bounds memory access in v3 onion service descriptor
          parsing. An attacker could exploit this bug by crafting an onion
          service descriptor that would crash any client that tried to visit
          it. Fixes bug 40392; bugfix on 0.3.0.1-alpha. This issue is also
          tracked as TROVE-2021-006 and CVE-2021-34550. Reported by Sergei
          Glazunov from Google's Project Zero.
    
      o Minor bugfixes (compiler warnings, backport from 0.4.6.3-rc):
        - Fix an indentation problem that led to a warning from GCC 11.1.1.
          Fixes bug 40380; bugfix on 0.3.0.1-alpha.
    
      o Minor features (compatibility, backport from 0.4.6.4-rc):
        - Remove an assertion function related to TLS renegotiation. It was
          used nowhere outside the unit tests, and it was breaking
          compilation with recent alpha releases of OpenSSL 3.0.0. Closes
          ticket 40399.
    
      o Minor features (fallback directory list, backport from 0.4.6.2-alpha):
        - Regenerate the list of fallback directories to contain a new set
          of 200 relays. Closes ticket 40265.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2021/06/10.
    
    
    Changes in version 0.4.5.8 - 2021-05-10
      Tor 0.4.5.8 fixes several bugs in earlier version, backporting fixes
      from the 0.4.6.x series.
    
      o Minor features (compatibility, Linux seccomp sandbox, backport from 0.4.6.3-rc):
        - Add a workaround to enable the Linux sandbox to work correctly
          with Glibc 2.33. This version of Glibc has started using the
          fstatat() system call, which previously our sandbox did not allow.
          Closes ticket 40382; see the ticket for a discussion of trade-offs.
    
      o Minor features (compilation, backport from 0.4.6.3-rc):
        - Make the autoconf script build correctly with autoconf versions
          2.70 and later. Closes part of ticket 40335.
    
      o Minor features (fallback directory list, backport from 0.4.6.2-alpha):
        - Regenerate the list of fallback directories to contain a new set
          of 200 relays. Closes ticket 40265.
    
      o Minor features (geoip data):
        - Update the geoip files to match the IPFire Location Database, as
          retrieved on 2021/05/07.
    
      o Minor features (onion services):
        - Add warning message when connecting to now deprecated v2 onion
          services. As announced, Tor 0.4.5.x is the last series that will
          support v2 onions. Closes ticket 40373.
    
      o Minor bugfixes (bridge, pluggable transport, backport from 0.4.6.2-alpha):
        - Fix a regression that made it impossible start Tor using a bridge
          line with a transport name and no fingerprint. Fixes bug 40360;
          bugfix on 0.4.5.4-rc.
    
      o Minor bugfixes (build, cross-compilation, backport from 0.4.6.3-rc):
        - Allow a custom "ar" for cross-compilation. Our previous build
          script had used the $AR environment variable in most places, but
          it missed one. Fixes bug 40369; bugfix on 0.4.5.1-alpha.
    
      o Minor bugfixes (channel, DoS, backport from 0.4.6.2-alpha):
        - Fix a non-fatal BUG() message due to a too-early free of a string,
          when listing a client connection from the DoS defenses subsystem.
          Fixes bug 40345; bugfix on 0.4.3.4-rc.
    
      o Minor bugfixes (compiler warnings, backport from 0.4.6.3-rc):
        - Fix an indentation problem that led to a warning from GCC 11.1.1.
          Fixes bug 40380; bugfix on 0.3.0.1-alpha.
    
      o Minor bugfixes (controller, backport from 0.4.6.1-alpha):
        - Fix a "BUG" warning that would appear when a controller chooses
          the first hop for a circuit, and that circuit completes. Fixes bug
          40285; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion service, client, memory leak, backport from 0.4.6.3-rc):
        - Fix a bug where an expired cached descriptor could get overwritten
          with a new one without freeing it, leading to a memory leak. Fixes
          bug 40356; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (testing, BSD, backport from 0.4.6.2-alpha):
        - Fix pattern-matching errors when patterns expand to invalid paths
          on BSD systems. Fixes bug 40318; bugfix on 0.4.5.1-alpha. Patch by
          Daniel Pinto.
    
    
    Changes in version 0.3.5.14 - 2021-03-16
      Tor 0.3.5.14 backports fixes for two important denial-of-service bugs
      in earlier versions of Tor.
    
      One of these vulnerabilities (TROVE-2021-001) would allow an attacker
      who can send directory data to a Tor instance to force that Tor
      instance to consume huge amounts of CPU. This is easiest to exploit
      against authorities, since anybody can upload to them, but directory
      caches could also exploit this vulnerability against relays or clients
      when they download. The other vulnerability (TROVE-2021-002) only
      affects directory authorities, and would allow an attacker to remotely
      crash the authority with an assertion failure. Patches have already
      been provided to the authority operators, to help ensure
      network stability.
    
      We recommend that everybody upgrade to one of the releases that fixes
      these issues (0.3.5.14, 0.4.4.8, or 0.4.5.7) as they become available
      to you.
    
      This release also updates our GeoIP data source, and fixes a
      compatibility issue.
    
      o Major bugfixes (security, denial of service, backport from 0.4.5.7):
        - Disable the dump_desc() function that we used to dump unparseable
          information to disk. It was called incorrectly in several places,
          in a way that could lead to excessive CPU usage. Fixes bug 40286;
          bugfix on 0.2.2.1-alpha. This bug is also tracked as TROVE-2021-
          001 and CVE-2021-28089.
        - Fix a bug in appending detached signatures to a pending consensus
          document that could be used to crash a directory authority. Fixes
          bug 40316; bugfix on 0.2.2.6-alpha. Tracked as TROVE-2021-002
          and CVE-2021-28090.
    
      o Minor features (geoip data, backport from 0.4.5.7):
        - We have switched geoip data sources. Previously we shipped IP-to-
          country mappings from Maxmind's GeoLite2, but in 2019 they changed
          their licensing terms, so we were unable to update them after that
          point. We now ship geoip files based on the IPFire Location
          Database instead. (See https://location.ipfire.org/ for more
          information). This release updates our geoip files to match the
          IPFire Location Database as retrieved on 2021/03/12. Closes
          ticket 40224.
    
      o Removed features (mallinfo deprecated, backport from 0.4.5.7):
        - Remove mallinfo() usage entirely. Libc 2.33+ now deprecates it.
          Closes ticket 40309.
    
    
    Changes in version 0.4.4.8 - 2021-03-16
      Tor 0.4.4.8 backports fixes for two important denial-of-service bugs
      in earlier versions of Tor.
    
      One of these vulnerabilities (TROVE-2021-001) would allow an attacker
      who can send directory data to a Tor instance to force that Tor
      instance to consume huge amounts of CPU. This is easiest to exploit
      against authorities, since anybody can upload to them, but directory
      caches could also exploit this vulnerability against relays or clients
      when they download. The other vulnerability (TROVE-2021-002) only
      affects directory authorities, and would allow an attacker to remotely
      crash the authority with an assertion failure. Patches have already
      been provided to the authority operators, to help ensure
      network stability.
    
      We recommend that everybody upgrade to one of the releases that fixes
      these issues (0.3.5.14, 0.4.4.8, or 0.4.5.7) as they become available
      to you.
    
      This release also updates our GeoIP data source, and fixes a
      compatibility issue.
    
      o Major bugfixes (security, denial of service, backport from 0.4.5.7):
        - Disable the dump_desc() function that we used to dump unparseable
          information to disk. It was called incorrectly in several places,
          in a way that could lead to excessive CPU usage. Fixes bug 40286;
          bugfix on 0.2.2.1-alpha. This bug is also tracked as TROVE-2021-
          001 and CVE-2021-28089.
        - Fix a bug in appending detached signatures to a pending consensus
          document that could be used to crash a directory authority. Fixes
          bug 40316; bugfix on 0.2.2.6-alpha. Tracked as TROVE-2021-002
          and CVE-2021-28090.
    
      o Minor features (geoip data, backport from 0.4.5.7):
        - We have switched geoip data sources. Previously we shipped IP-to-
          country mappings from Maxmind's GeoLite2, but in 2019 they changed
          their licensing terms, so we were unable to update them after that
          point. We now ship geoip files based on the IPFire Location
          Database instead. (See https://location.ipfire.org/ for more
          information). This release updates our geoip files to match the
          IPFire Location Database as retrieved on 2021/03/12. Closes
          ticket 40224.
    
      o Removed features (mallinfo deprecated, backport from 0.4.5.7):
        - Remove mallinfo() usage entirely. Libc 2.33+ now deprecates it.
          Closes ticket 40309.
    
    
    Changes in version 0.4.5.7 - 2021-03-16
      Tor 0.4.5.7 fixes two important denial-of-service bugs in earlier
      versions of Tor.
    
      One of these vulnerabilities (TROVE-2021-001) would allow an attacker
      who can send directory data to a Tor instance to force that Tor
      instance to consume huge amounts of CPU. This is easiest to exploit
      against authorities, since anybody can upload to them, but directory
      caches could also exploit this vulnerability against relays or clients
      when they download. The other vulnerability (TROVE-2021-002) only
      affects directory authorities, and would allow an attacker to remotely
      crash the authority with an assertion failure. Patches have already
      been provided to the authority operators, to help ensure
      network stability.
    
      We recommend that everybody upgrade to one of the releases that fixes
      these issues (0.3.5.14, 0.4.4.8, or 0.4.5.7) as they become available
      to you.
    
      This release also updates our GeoIP data source, and fixes a few
      smaller bugs in earlier releases.
    
      o Major bugfixes (security, denial of service):
        - Disable the dump_desc() function that we used to dump unparseable
          information to disk. It was called incorrectly in several places,
          in a way that could lead to excessive CPU usage. Fixes bug 40286;
          bugfix on 0.2.2.1-alpha. This bug is also tracked as TROVE-2021-
          001 and CVE-2021-28089.
        - Fix a bug in appending detached signatures to a pending consensus
          document that could be used to crash a directory authority. Fixes
          bug 40316; bugfix on 0.2.2.6-alpha. Tracked as TROVE-2021-002
          and CVE-2021-28090.
    
      o Minor features (geoip data):
        - We have switched geoip data sources. Previously we shipped IP-to-
          country mappings from Maxmind's GeoLite2, but in 2019 they changed
          their licensing terms, so we were unable to update them after that
          point. We now ship geoip files based on the IPFire Location
          Database instead. (See https://location.ipfire.org/ for more
          information). This release updates our geoip files to match the
          IPFire Location Database as retrieved on 2021/03/12. Closes
          ticket 40224.
    
      o Minor bugfixes (directory authority):
        - Now that exit relays don't allow exit connections to directory
          authority DirPorts (to prevent network reentry), disable
          authorities' reachability self test on the DirPort. Fixes bug
          40287; bugfix on 0.4.5.5-rc.
    
      o Minor bugfixes (documentation):
        - Fix a formatting error in the documentation for
          VirtualAddrNetworkIPv6. Fixes bug 40256; bugfix on 0.2.9.4-alpha.
    
      o Minor bugfixes (Linux, relay):
        - Fix a bug in determining total available system memory that would
          have been triggered if the format of Linux's /proc/meminfo file
          had ever changed to include "MemTotal:" in the middle of a line.
          Fixes bug 40315; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (metrics port):
        - Fix a BUG() warning on the MetricsPort for an internal missing
          handler. Fixes bug 40295; bugfix on 0.4.5.1-alpha.
    
      o Minor bugfixes (onion service):
        - Remove a harmless BUG() warning when reloading tor configured with
          onion services. Fixes bug 40334; bugfix on 0.4.5.1-alpha.
    
      o Minor bugfixes (portability):
        - Fix a non-portable usage of "==" with "test" in the configure
          script. Fixes bug 40298; bugfix on 0.4.5.1-alpha.
    
      o Minor bugfixes (relay):
        - Remove a spammy log notice falsely claiming that the IPv4/v6
          address was missing. Fixes bug 40300; bugfix on 0.4.5.1-alpha.
        - Do not query the address cache early in the boot process when
          deciding if a relay needs to fetch early directory information
          from an authority. This bug resulted in a relay falsely believing
          it didn't have an address and thus triggering an authority fetch
          at each boot. Related to our fix for 40300.
    
      o Removed features (mallinfo deprecated):
        - Remove mallinfo() usage entirely. Libc 2.33+ now deprecates it.
          Closes ticket 40309.
    
    
    Changes in version 0.4.5.6 - 2021-02-15
      The Tor 0.4.5.x release series is dedicated to the memory of Karsten
      Loesing (1979-2020), Tor developer, cypherpunk, husband, and father.
      Karsten is best known for creating the Tor metrics portal and leading
      the metrics team, but he was involved in Tor from the early days. For
      example, while he was still a student he invented and implemented the
      v2 onion service directory design, and he also served as an ambassador
      to the many German researchers working in the anonymity field. We
      loved him and respected him for his patience, his consistency, and his
      welcoming approach to growing our community.
    
      This release series introduces significant improvements in relay IPv6
      address discovery, a new "MetricsPort" mechanism for relay operators
      to measure performance, LTTng support, build system improvements to
      help when using Tor as a static library, and significant bugfixes
      related to Windows relay performance. It also includes numerous
      smaller features and bugfixes.
    
      Below are the changes since 0.4.4.7. For a list of changes since
      0.4.5.5-rc, see the ChangeLog file.
    
      o Major features (build):
        - When building Tor, first link all object files into a single
          static library. This may help with embedding Tor in other
          programs. Note that most Tor functions do not constitute a part of
          a stable or supported API: only those functions in tor_api.h
          should be used if embedding Tor. Closes ticket 40127.
    
      o Major features (metrics):
        - Introduce a new MetricsPort which exposes, through an HTTP
          interface, a series of metrics that tor collects at runtime. At
          the moment, the only supported output format is Prometheus data
          model. Closes ticket 40063. See the manual page for more
          information and security considerations.
    
      o Major features (relay, IPv6):
        - The torrc option Address now supports IPv6. This unifies our
          address discovery interface to support IPv4, IPv6, and hostnames.
          Closes ticket 33233.
        - Launch IPv4 and IPv6 ORPort self-test circuits on relays and
          bridges. Closes ticket 33222.
        - Relays now automatically bind on IPv6 for their ORPort, unless
          specified otherwise with the IPv4Only flag. Closes ticket 33246.
        - When a relay with IPv6 support is told to open a connection to
          another relay, and the extend cell lists both IPv4 and IPv6
          addresses, the first relay now picks randomly which address to
          use. Closes ticket 33220.
        - Relays now track their IPv6 ORPort reachability separately from
          the reachability of their IPv4 ORPort. They will not publish a
          descriptor unless _both_ ports appear to be externally reachable.
          Closes ticket 34067.
    
      o Major features (tracing):
        - Add event-tracing library support for USDT and LTTng-UST, and a
          few tracepoints in the circuit subsystem. More will come
          incrementally. This feature is compiled out by default: it needs
          to be enabled at configure time. See documentation in
          doc/HACKING/Tracing.md. Closes ticket 32910.
    
      o Major bugfixes (directory cache, performance, windows):
        - Limit the number of items in the consensus diff cache to 64 on
          Windows. We hope this will mitigate an issue where Windows relay
          operators reported Tor using 100% CPU, while we investigate better
          solutions. Fixes bug 24857; bugfix on 0.3.1.1-alpha.
    
      o Major bugfixes (relay, windows):
        - Fix a bug in our implementation of condition variables on Windows.
          Previously, a relay on Windows would use 100% CPU after running
          for some time. Because of this change, Tor now require Windows
          Vista or later to build and run. Fixes bug 30187; bugfix on
          0.2.6.3-alpha. (This bug became more serious in 0.3.1.1-alpha with
          the introduction of consensus diffs.) Patch by Daniel Pinto.
    
      o Major bugfixes (TLS, buffer):
        - When attempting to read N bytes on a TLS connection, really try to
          read all N bytes. Previously, Tor would stop reading after the
          first TLS record, which can be smaller than the N bytes requested,
          and not check for more data until the next mainloop event. Fixes
          bug 40006; bugfix on 0.1.0.5-rc.
    
      o Minor features (address discovery):
        - If no Address statements are found, relays now prioritize guessing
          their address by looking at the local interface instead of the
          local hostname. If the interface address can't be found, the local
          hostname is used. Closes ticket 33238.
    
      o Minor features (admin tools):
        - Add a new --format argument to -key-expiration option to allow
          specifying the time format of the expiration date. Adds Unix
          timestamp format support. Patch by Daniel Pinto. Closes
          ticket 30045.
    
      o Minor features (authority, logging):
        - Log more information for directory authority operators during the
          consensus voting process, and while processing relay descriptors.
          Closes ticket 40245.
    
      o Minor features (bootstrap reporting):
        - When reporting bootstrapping status on a relay, do not consider
          connections that have never been the target of an origin circuit.
          Previously, all connection failures were treated as potential
          bootstrapping failures, including connections that had been opened
          because of client requests. Closes ticket 25061.
    
      o Minor features (build):
        - When running the configure script, try to detect version
          mismatches between the OpenSSL headers and libraries, and suggest
          that the user should try "--with-openssl-dir". Closes 40138.
        - If the configure script has given any warnings, remind the user
          about them at the end of the script. Related to 40138.
    
      o Minor features (configuration):
        - Allow using wildcards (* and ?) with the %include option on
          configuration files. Closes ticket 25140. Patch by Daniel Pinto.
        - Allow the configuration options EntryNodes, ExcludeNodes,
          ExcludeExitNodes, ExitNodes, MiddleNodes, HSLayer2Nodes and
          HSLayer3Nodes to be specified multiple times. Closes ticket 28361.
          Patch by Daniel Pinto.
    
      o Minor features (control port):
        - Add a DROPTIMEOUTS command to drop circuit build timeout history
          and reset the current timeout. Closes ticket 40002.
        - When a stream enters the AP_CONN_STATE_CONTROLLER_WAIT status,
          send a control port event. Closes ticket 32190. Patch by
          Neel Chauhan.
        - Introduce GETINFO "stats/ntor/{assigned/requested}" and
          "stats/tap/{assigned/requested}" to get the NTor and TAP circuit
          onion handshake counts respectively. Closes ticket 28279. Patch by
          Neel Chauhan.
    
      o Minor features (control port, IPv6):
        - Tor relays now try to report to the controller when they are
          launching an IPv6 self-test. Closes ticket 34068.
        - Introduce "GETINFO address/v4" and "GETINFO address/v6" in the
          control port to fetch the Tor host's respective IPv4 or IPv6
          address. We keep "GETINFO address" for backwards-compatibility.
          Closes ticket 40039. Patch by Neel Chauhan.
    
      o Minor features (directory authorities):
        - Add a new consensus method 30 that removes the unnecessary "="
          padding from ntor-onion-key. Closes ticket 7869. Patch by
          Daniel Pinto.
        - Directory authorities now reject descriptors from relays running
          Tor versions from the obsolete 0.4.1 series. Resolves ticket
          34357. Patch by Neel Chauhan.
        - The AssumeReachable option no longer stops directory authorities
          from checking whether other relays are running. A new
          AuthDirTestReachability option can be used to disable these
          checks. Closes ticket 34445.
        - When looking for possible Sybil attacks, also consider IPv6
          addresses. Two routers are considered to have "the same" address
          by this metric if they are in the same /64 network. Patch from
          Maurice Pibouin. Closes ticket 7193.
    
      o Minor features (directory authorities, IPv6):
        - Make authorities add their IPv6 ORPort (if any) to the trusted
          servers list. Authorities previously added only their IPv4
          addresses. Closes ticket 32822.
    
      o Minor features (documentation):
        - Mention the "!badexit" directive that can appear in an authority's
          approved-routers file, and update the description of the
          "!invalid" directive. Closes ticket 40188.
    
      o Minor features (ed25519, relay):
        - Save a relay's base64-encoded ed25519 identity key to the data
          directory in a file named fingerprint-ed25519. Closes ticket
          30642. Patch by Neel Chauhan.
    
      o Minor features (heartbeat):
        - Include the total number of inbound and outbound IPv4 and IPv6
          connections in the heartbeat message. Closes ticket 29113.
    
      o Minor features (IPv6, ExcludeNodes):
        - Handle IPv6 addresses in ExcludeNodes; previously they were
          ignored. Closes ticket 34065. Patch by Neel Chauhan.
    
      o Minor features (logging):
        - Add the running glibc version to the log, and the compiled glibc
          version to the library list returned when using --library-versions.
          Patch from Daniel Pinto. Closes ticket 40047.
        - Consider an HTTP 301 response to be an error (like a 404) when
          processing a directory response. Closes ticket 40053.
        - Log directory fetch statistics as a single line. Closes
          ticket 40159.
        - Provide more complete descriptions of our connections when logging
          about them. Closes ticket 40041.
        - When describing a relay in the logs, we now include its ed25519
          identity. Closes ticket 22668.
    
      o Minor features (onion services):
        - Only overwrite an onion service's existing hostname file if its
          contents are wrong. This enables read-only onion-service
          directories. Resolves ticket 40062. Patch by Neel Chauhan.
    
      o Minor features (pluggable transports):
        - Add an OutboundBindAddressPT option to allow users to specify
          which IPv4 and IPv6 address pluggable transports should use for
          outgoing IP packets. Tor does not have a way to enforce that the
          pluggable transport honors this option, so each pluggable transport
          needs to implement support on its own. Closes ticket 5304.
    
      o Minor features (protocol, proxy support, defense in depth):
        - Respond more deliberately to misbehaving proxies that leave
          leftover data on their connections, so as to make Tor even less
          likely to allow the proxies to pass their data off as having come
          from a relay. Closes ticket 40017.
    
      o Minor features (relay address tracking):
        - We now store relay addresses for OR connections in a more logical
          way. Previously we would sometimes overwrite the actual address of
          a connection with a "canonical address", and then store the "real
          address" elsewhere to remember it. We now track the "canonical
          address" elsewhere for the cases where we need it, and leave the
          connection's address alone. Closes ticket 33898.
    
      o Minor features (relay):
        - If a relay is unable to discover its address, attempt to learn it
          from the NETINFO cell. Closes ticket 40022.
        - Log immediately when launching a relay self-check. Previously we
          would try to log before launching checks, or approximately when we
          intended to launch checks, but this tended to be error-prone.
          Closes ticket 34137.
    
      o Minor features (relay, address discovery):
        - If Address option is not found in torrc, attempt to learn our
          address with the configured ORPort address if any. Closes
          ticket 33236.
    
      o Minor features (relay, IPv6):
        - Add an AssumeReachableIPv6 option to disable self-checking IPv6
          reachability. Closes part of ticket 33224.
        - Add new "assume-reachable" and "assume-reachable-ipv6" consensus
          parameters to be used in an emergency to tell relays that they
          should publish even if they cannot complete their ORPort self-
          checks. Closes ticket 34064 and part of 33224.
        - Allow relays to send IPv6-only extend cells. Closes ticket 33222.
        - Declare support for the Relay=3 subprotocol version. Closes
          ticket 33226.
        - When launching IPv6 ORPort self-test circuits, make sure that the
          second-last hop can initiate an IPv6 extend. Closes ticket 33222.
    
      o Minor features (safety):
        - Log a warning at startup if Tor is built with compile-time options
          that are likely to make it less stable or reliable. Closes
          ticket 18888.
    
      o Minor features (specification update):
        - Several fields in microdescriptors, router descriptors, and
          consensus documents that were formerly optional are now required.
          Implements proposal 315; closes ticket 40132.
    
      o Minor features (state management):
        - When loading the state file, remove entries from the statefile
          that have been obsolete for a long time. Ordinarily Tor preserves
          unrecognized entries in order to keep forward-compatibility, but
          these entries have not actually been used in any release since
          before 0.3.5.x. Closes ticket 40137.
    
      o Minor features (statistics, ipv6):
        - Relays now publish IPv6-specific counts of single-direction versus
          bidirectional relay connections. Closes ticket 33264.
        - Relays now publish their IPv6 read and write statistics over time,
          if statistics are enabled. Closes ticket 33263.
    
      o Minor features (subprotocol versions):
        - Use the new limitations on subprotocol versions due to proposal
          318 to simplify our implementation. Part of ticket 40133.
    
      o Minor features (testing configuration):
        - The TestingTorNetwork option no longer implicitly sets
          AssumeReachable to 1. This change allows us to test relays' self-
          testing mechanisms, and to test authorities' relay-testing
          functionality. Closes ticket 34446.
    
      o Minor features (testing):
        - Added unit tests for channel_matches_target_addr_for_extend().
          Closes Ticket 33919. Patch by MrSquanchee.
    
      o Minor bugfixes (circuit padding):
        - When circpad_send_padding_cell_for_callback is called,
          `is_padding_timer_scheduled` flag was not reset. Now it is set to
          0 at the top of that function. Fixes bug 32671; bugfix
          on 0.4.0.1-alpha.
        - Add a per-circuit padding machine instance counter, so we can
          differentiate between shutdown requests for old machines on a
          circuit. Fixes bug 30992; bugfix on 0.4.1.1-alpha.
        - Add the ability to keep circuit padding machines if they match a
          set of circuit states or purposes. This allows us to have machines
          that start up under some conditions but don't shut down under
          others. We now use this mask to avoid starting up introduction
          circuit padding again after the machines have already completed.
          Fixes bug 32040; bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (circuit, handshake):
        - In the v3 handshaking code, use connection_or_change_state() to
          change the state. Previously, we changed the state directly, but
          this did not pass the state change to the pubsub or channel
          objects, potentially leading to bugs. Fixes bug 32880; bugfix on
          0.2.3.6-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (compilation):
        - Change the linker flag ordering in our library search code so that
          it works for compilers that need the libraries to be listed in the
          right order. Fixes bug 33624; bugfix on 0.1.1.0-alpha.
        - Fix the "--enable-static-tor" switch to properly set the "-static"
          compile option onto the tor binary only. Fixes bug 40111; bugfix
          on 0.2.3.1-alpha.
    
      o Minor bugfixes (configuration):
        - Exit Tor on a misconfiguration when the Bridge line is configured
          to use a transport but no corresponding ClientTransportPlugin can
          be found. Prior to this fix, Tor would attempt to connect to the
          bridge directly without using the transport, making it easier for
          adversaries to notice the bridge. Fixes bug 25528; bugfix
          on 0.2.6.1-alpha.
    
      o Minor bugfixes (control port):
        - Make sure we send the SOCKS request address in relay begin cells
          when a stream is attached with the purpose
          CIRCUIT_PURPOSE_CONTROLLER. Fixes bug 33124; bugfix on 0.0.5.
          Patch by Neel Chauhan.
    
      o Minor bugfixes (crash, relay, signing key):
        - Avoid assertion failures when we run Tor from the command line
          with `--key-expiration sign`, but an ORPort is not set. Fixes bug
          40015; bugfix on 0.3.2.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (logging):
        - Avoid a spurious log message about missing subprotocol versions,
          when the consensus that we're reading from is older than the
          current release. Previously we had made this message nonfatal, but
          in practice, it is never relevant when the consensus is older than
          the current release. Fixes bug 40281; bugfix on 0.4.0.1-alpha.
        - Remove trailing whitespace from control event log messages. Fixes
          bug 32178; bugfix on 0.1.1.1-alpha. Based on a patch by
          Amadeusz Pawlik.
        - Turn warning-level log message about SENDME failure into a debug-
          level message. (This event can happen naturally, and is no reason
          for concern). Fixes bug 40142; bugfix on 0.4.1.1-alpha.
        - When logging a rate-limited message about how many messages have
          been suppressed in the last N seconds, give an accurate value for
          N, rounded up to the nearest minute. Previously we would report
          the size of the rate-limiting interval, regardless of when the
          messages started to occur. Fixes bug 19431; bugfix
          on 0.2.2.16-alpha.
    
      o Minor bugfixes (onion services):
        - Avoid a non-fatal assertion in certain edge-cases when
          establishing a circuit to an onion service. Fixes bug 32666;
          bugfix on 0.3.0.3-alpha.
    
      o Minor bugfixes (rust, protocol versions):
        - Declare support for the onion service introduction point denial of
          service extensions when building with Rust. Fixes bug 34248;
          bugfix on 0.4.2.1-alpha.
        - Make Rust protocol version support checks consistent with the
          undocumented error behavior of the corresponding C code. Fixes bug
          34251; bugfix on 0.3.3.5-rc.
    
      o Minor bugfixes (self-testing):
        - When receiving an incoming circuit, only accept it as evidence
          that we are reachable if the declared address of its channel is
          the same address we think that we have. Otherwise, it could be
          evidence that we're reachable on some other address. Fixes bug
          20165; bugfix on 0.1.0.1-rc.
    
      o Minor bugfixes (spec conformance):
        - Use the correct key type when generating signing->link
          certificates. Fixes bug 40124; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (subprotocol versions):
        - Consistently reject extra commas, instead of only rejecting
          leading commas. Fixes bug 27194; bugfix on 0.2.9.4-alpha.
        - In summarize_protover_flags(), treat empty strings the same as
          NULL. This prevents protocols_known from being set. Previously, we
          treated empty strings as normal strings, which led to
          protocols_known being set. Fixes bug 34232; bugfix on
          0.3.3.2-alpha. Patch by Neel Chauhan.
    
      o Code simplification and refactoring:
        - Add and use a set of functions to perform down-casts on constant
          connection and channel pointers. Closes ticket 40046.
        - Refactor our code that logs descriptions of connections, channels,
          and the peers on them, to use a single call path. This change
          enables us to refactor the data types that they use, and eliminates
          many confusing usages of those types. Closes ticket 40041.
        - Refactor some common node selection code into a single function.
          Closes ticket 34200.
        - Remove the now-redundant 'outbuf_flushlen' field from our
          connection type. It was previously used for an older version of
          our rate-limiting logic. Closes ticket 33097.
        - Rename "fascist_firewall_*" identifiers to "reachable_addr_*"
          instead, for consistency with other code. Closes ticket 18106.
        - Rename functions about "advertised" ports which are not in fact
          guaranteed to return the ports that have been advertised. Closes
          ticket 40055.
        - Split implementation of several command line options from
          options_init_from_torrc into smaller isolated functions. Patch by
          Daniel Pinto. Closes ticket 40102.
        - When an extend cell is missing an IPv4 or IPv6 address, fill in
          the address from the extend info. This is similar to what was done
          in ticket 33633 for ed25519 keys. Closes ticket 33816. Patch by
          Neel Chauhan.
    
      o Deprecated features:
        - The "non-builtin" argument to the "--dump-config" command is now
          deprecated. When it works, it behaves the same as "short", which
          you should use instead. Closes ticket 33398.
    
      o Documentation:
        - Replace URLs from our old bugtracker so that they refer to the new
          bugtracker and wiki. Closes ticket 40101.
    
      o Removed features:
        - We no longer ship or build a "tor.service" file for use with
          systemd. No distribution included this script unmodified, and we
          don't have the expertise ourselves to maintain this in a way that
          all the various systemd-based distributions can use. Closes
          ticket 30797.
        - We no longer ship support for the Android logging API. Modern
          versions of Android can use the syslog API instead. Closes
          ticket 32181.
        - The "optimistic data" feature is now always on; there is no longer
          an option to disable it from the torrc file or from the consensus
          directory. Closes part of 40139.
        - The "usecreatefast" network parameter is now removed; there is no
          longer an option for authorities to turn it off. Closes part
          of 40139.
    
      o Testing:
        - Add unit tests for bandwidth statistics manipulation functions.
          Closes ticket 33812. Patch by MrSquanchee.
    
      o Code simplification and refactoring (autoconf):
        - Remove autoconf checks for unused funcs and headers. Closes ticket
          31699; Patch by @bduszel
    
      o Code simplification and refactoring (maintainer scripts):
        - Disable by default the pre-commit hook. Use the environment
          variable TOR_EXTRA_PRE_COMMIT_CHECKS in order to run it.
          Furthermore, stop running practracker in the pre-commit hook and
          make check-local. Closes ticket 40019.
    
      o Code simplification and refactoring (relay address):
        - Most of IPv4 representation was using "uint32_t". It has now been
          moved to use the internal "tor_addr_t" interface instead. This is
          so we can properly integrate IPv6 along IPv4 with common
          interfaces. Closes ticket 40043.
    
      o Documentation (manual page):
        - Move them from doc/ to doc/man/. Closes ticket 40044.
        - Describe the status of the "Sandbox" option more accurately. It is
          no longer "experimental", but it _is_ dependent on kernel and libc
          versions. Closes ticket 23378.
    
      o Documentation (tracing):
        - Document in depth the circuit subsystem trace events in the new
          doc/tracing/EventsCircuit.md. Closes ticket 40036.
    
      o Removed features (controller):
        - Remove the "GETINFO network-status" controller command. It has
          been deprecated since 0.3.1.1-alpha. Closes ticket 22473.
    
    
    Changes in version 0.4.4.7 - 2021-02-03
      Tor 0.4.4.7 backports numerous bugfixes from later releases,
      including one that made v3 onion services more susceptible to
      denial-of-service attacks, and a feature that makes some kinds of
      DoS attacks harder to perform.
    
      o Major bugfixes (onion service v3, backport from 0.4.5.3-rc):
        - Stop requiring a live consensus for v3 clients and services, and
          allow a "reasonably live" consensus instead. This allows v3 onion
          services to work even if the authorities fail to generate a
          consensus for more than 2 hours in a row. Fixes bug 40237; bugfix
          on 0.3.5.1-alpha.
    
      o Major feature (exit, backport from 0.4.5.5-rc):
        - Re-entry into the network is now denied at the Exit level to all
          relays' ORPorts and authorities' ORPorts and DirPorts. This change
          should help mitgate a set of denial-of-service attacks. Closes
          ticket 2667.
    
      o Minor feature (build system, backport from 0.4.5.4-rc):
        - New "make lsp" command to generate the compile_commands.json file
          used by the ccls language server. The "bear" program is needed for
          this. Closes ticket 40227.
    
      o Minor features (compilation, backport from 0.4.5.2-rc):
        - Disable deprecation warnings when building with OpenSSL 3.0.0 or
          later. There are a number of APIs newly deprecated in OpenSSL
          3.0.0 that Tor still requires. (A later version of Tor will try to
          stop depending on these APIs.) Closes ticket 40165.
    
      o Minor features (crypto, backport from 0.4.5.3-rc):
        - Fix undefined behavior on our Keccak library. The bug only
          appeared on platforms with 32-byte CPU cache lines (e.g. armv5tel)
          and would result in wrong digests. Fixes bug 40210; bugfix on
          0.2.8.1-alpha. Thanks to Bernhard Übelacker, Arnd Bergmann and
          weasel for diagnosing this.
    
      o Minor bugfixes (compatibility, backport from 0.4.5.1-rc):
        - Strip '\r' characters when reading text files on Unix platforms.
          This should resolve an issue where a relay operator migrates a
          relay from Windows to Unix, but does not change the line ending of
          Tor's various state files to match the platform, and the CRLF line
          endings from Windows end up leaking into other files such as the
          extra-info document. Fixes bug 33781; bugfix on 0.0.9pre5.
    
      o Minor bugfixes (compilation, backport from 0.4.5.3-rc):
        - Fix a compilation warning about unreachable fallthrough
          annotations when building with "--enable-all-bugs-are-fatal" on
          some compilers. Fixes bug 40241; bugfix on 0.3.5.4-alpha.
    
      o Minor bugfixes (SOCKS5, backport from 0.4.5.3-rc):
        - Handle partial SOCKS5 messages correctly. Previously, our code
          would send an incorrect error message if it got a SOCKS5 request
          that wasn't complete. Fixes bug 40190; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.4.5.2-alpha):
        - Fix the `config/parse_tcp_proxy_line` test so that it works
          correctly on systems where the DNS provider hijacks invalid
          queries. Fixes part of bug 40179; bugfix on 0.4.3.1-alpha.
        - Fix our Python reference-implementation for the v3 onion service
          handshake so that it works correctly with the version of hashlib
          provided by Python 3.9. Fixes part of bug 40179; bugfix
          on 0.3.1.6-rc.
        - Fix the `tortls/openssl/log_one_error` test to work with OpenSSL
          3.0.0. Fixes bug 40170; bugfix on 0.2.8.1-alpha.
    
    
    Changes in version 0.4.3.8 - 2021-02-03
      Tor 0.4.3.8 backports numerous bugfixes from later releases,
      including one that made v3 onion services more susceptible to
      denial-of-service attacks, and a feature that makes some kinds of
      DoS attacks harder to perform.
    
      Note that this is, in all likelihood, the last release of Tor 0.4.3.x,
      which will reach end-of-life on 15 Feb 2021.
    
      o Major bugfixes (onion service v3, backport from 0.4.5.3-rc):
        - Stop requiring a live consensus for v3 clients and services, and
          allow a "reasonably live" consensus instead. This allows v3 onion
          services to work even if the authorities fail to generate a
          consensus for more than 2 hours in a row. Fixes bug 40237; bugfix
          on 0.3.5.1-alpha.
    
      o Major bugfixes (stats, onion services, backport from 0.4.4.5):
        - Fix a bug where we were undercounting the Tor network's total
          onion service traffic, by ignoring any traffic originating from
          clients. Now we count traffic from both clients and services.
          Fixes bug 40117; bugfix on 0.2.6.2-alpha.
    
      o Major feature (exit, backport from 0.4.5.5-rc):
        - Re-entry into the network is now denied at the Exit level to all
          relays' ORPorts and authorities' ORPorts and DirPorts. This change
          should help mitgate a set of denial-of-service attacks. Closes
          ticket 2667.
    
      o Minor feature (build system, backport from 0.4.5.4-rc):
        - New "make lsp" command to generate the compile_commands.json file
          used by the ccls language server. The "bear" program is needed for
          this. Closes ticket 40227.
    
      o Minor features (compilation, backport from 0.4.5.2-rc):
        - Disable deprecation warnings when building with OpenSSL 3.0.0 or
          later. There are a number of APIs newly deprecated in OpenSSL
          3.0.0 that Tor still requires. (A later version of Tor will try to
          stop depending on these APIs.) Closes ticket 40165.
    
      o Minor features (crypto, backport from 0.4.5.3-rc):
        - Fix undefined behavior on our Keccak library. The bug only
          appeared on platforms with 32-byte CPU cache lines (e.g. armv5tel)
          and would result in wrong digests. Fixes bug 40210; bugfix on
          0.2.8.1-alpha. Thanks to Bernhard Übelacker, Arnd Bergmann and
          weasel for diagnosing this.
    
      o Minor bugfixes (compatibility, backport from 0.4.5.1-rc):
        - Strip '\r' characters when reading text files on Unix platforms.
          This should resolve an issue where a relay operator migrates a
          relay from Windows to Unix, but does not change the line ending of
          Tor's various state files to match the platform, and the CRLF line
          endings from Windows end up leaking into other files such as the
          extra-info document. Fixes bug 33781; bugfix on 0.0.9pre5.
    
      o Minor bugfixes (compilation, backport from 0.4.5.1-rc):
        - Resolve a compilation warning that could occur in
          test_connection.c. Fixes bug 40113; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (compilation, backport from 0.4.5.3-rc):
        - Fix a compilation warning about unreachable fallthrough
          annotations when building with "--enable-all-bugs-are-fatal" on
          some compilers. Fixes bug 40241; bugfix on 0.3.5.4-alpha.
    
      o Minor bugfixes (SOCKS5, backport from 0.4.5.3-rc):
        - Handle partial SOCKS5 messages correctly. Previously, our code
          would send an incorrect error message if it got a SOCKS5 request
          that wasn't complete. Fixes bug 40190; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.4.5.2-alpha):
        - Fix the `config/parse_tcp_proxy_line` test so that it works
          correctly on systems where the DNS provider hijacks invalid
          queries. Fixes part of bug 40179; bugfix on 0.4.3.1-alpha.
        - Fix our Python reference-implementation for the v3 onion service
          handshake so that it works correctly with the version of hashlib
          provided by Python 3.9. Fixes part of bug 40179; bugfix
          on 0.3.1.6-rc.
        - Fix the `tortls/openssl/log_one_error` test to work with OpenSSL
          3.0.0. Fixes bug 40170; bugfix on 0.2.8.1-alpha.
    
    
    Changes in version 0.3.5.13 - 2020-02-03
      Tor 0.3.5.13 backports numerous bugfixes from later releases,
      including one that made v3 onion services more susceptible to
      denial-of-service attacks, and a feature that makes some kinds of
      DoS attacks harder to perform.
    
      o Major bugfixes (onion service v3, backport from 0.4.5.3-rc):
        - Stop requiring a live consensus for v3 clients and services, and
          allow a "reasonably live" consensus instead. This allows v3 onion
          services to work even if the authorities fail to generate a
          consensus for more than 2 hours in a row. Fixes bug 40237; bugfix
          on 0.3.5.1-alpha.
    
      o Major bugfixes (stats, onion services, backport from 0.4.4.5):
        - Fix a bug where we were undercounting the Tor network's total
          onion service traffic, by ignoring any traffic originating from
          clients. Now we count traffic from both clients and services.
          Fixes bug 40117; bugfix on 0.2.6.2-alpha.
    
      o Major feature (exit, backport from 0.4.5.5-rc):
        - Re-entry into the network is now denied at the Exit level to all
          relays' ORPorts and authorities' ORPorts and DirPorts. This change
          should help mitgate a set of denial-of-service attacks. Closes
          ticket 2667.
    
      o Minor feature (build system, backport from 0.4.5.4-rc):
        - New "make lsp" command to generate the compile_commands.json file
          used by the ccls language server. The "bear" program is needed for
          this. Closes ticket 40227.
    
      o Minor features (compilation, backport from 0.4.5.2-rc):
        - Disable deprecation warnings when building with OpenSSL 3.0.0 or
          later. There are a number of APIs newly deprecated in OpenSSL
          3.0.0 that Tor still requires. (A later version of Tor will try to
          stop depending on these APIs.) Closes ticket 40165.
    
      o Minor features (crypto, backport from 0.4.5.3-rc):
        - Fix undefined behavior on our Keccak library. The bug only
          appeared on platforms with 32-byte CPU cache lines (e.g. armv5tel)
          and would result in wrong digests. Fixes bug 40210; bugfix on
          0.2.8.1-alpha. Thanks to Bernhard Übelacker, Arnd Bergmann and
          weasel for diagnosing this.
    
      o Minor bugfixes (compatibility, backport from 0.4.5.1-rc):
        - Strip '\r' characters when reading text files on Unix platforms.
          This should resolve an issue where a relay operator migrates a
          relay from Windows to Unix, but does not change the line ending of
          Tor's various state files to match the platform, and the CRLF line
          endings from Windows end up leaking into other files such as the
          extra-info document. Fixes bug 33781; bugfix on 0.0.9pre5.
    
      o Minor bugfixes (compilation, backport from 0.4.5.1-rc):
        - Resolve a compilation warning that could occur in
          test_connection.c. Fixes bug 40113; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (compilation, backport from 0.4.5.3-rc):
        - Fix a compilation warning about unreachable fallthrough
          annotations when building with "--enable-all-bugs-are-fatal" on
          some compilers. Fixes bug 40241; bugfix on 0.3.5.4-alpha.
    
      o Minor bugfixes (SOCKS5, backport from 0.4.5.3-rc):
        - Handle partial SOCKS5 messages correctly. Previously, our code
          would send an incorrect error message if it got a SOCKS5 request
          that wasn't complete. Fixes bug 40190; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.4.5.2-alpha):
        - Fix our Python reference-implementation for the v3 onion service
          handshake so that it works correctly with the version of hashlib
          provided by Python 3.9. Fixes part of bug 40179; bugfix
          on 0.3.1.6-rc.
        - Fix the `tortls/openssl/log_one_error` test to work with OpenSSL
          3.0.0. Fixes bug 40170; bugfix on 0.2.8.1-alpha.
    
    
    Changes in version 0.4.4.6 - 2020-11-12
      Tor 0.4.4.6 is the second stable release in the 0.4.4.x series. It
      backports fixes from later releases, including a fix for TROVE-2020-
      005, a security issue that could be used, under certain cases, by an
      adversary to observe traffic patterns on a limited number of circuits
      intended for a different relay.
    
      o Major bugfixes (security, backport from 0.4.5.1-alpha):
        - When completing a channel, relays now check more thoroughly to
          make sure that it matches any pending circuits before attaching
          those circuits. Previously, address correctness and Ed25519
          identities were not checked in this case, but only when extending
          circuits on an existing channel. Fixes bug 40080; bugfix on
          0.2.7.2-alpha. Resolves TROVE-2020-005.
    
      o Minor features (directory authorities, backport from 0.4.5.1-alpha):
        - Authorities now list a different set of protocols as required and
          recommended. These lists have been chosen so that only truly
          recommended and/or required protocols are included, and so that
          clients using 0.2.9 or later will continue to work (even though
          they are not supported), whereas only relays running 0.3.5 or
          later will meet the requirements. Closes ticket 40162.
        - Make it possible to specify multiple ConsensusParams torrc lines.
          Now directory authority operators can for example put the main
          ConsensusParams config in one torrc file and then add to it from a
          different torrc file. Closes ticket 40164.
    
      o Minor features (subprotocol versions, backport from 0.4.5.1-alpha):
        - Tor no longer allows subprotocol versions larger than 63.
          Previously version numbers up to UINT32_MAX were allowed, which
          significantly complicated our code. Implements proposal 318;
          closes ticket 40133.
    
      o Minor features (tests, v2 onion services, backport from 0.4.5.1-alpha):
        - Fix a rendezvous cache unit test that was triggering an underflow
          on the global rend cache allocation. Fixes bug 40125; bugfix
          on 0.2.8.1-alpha.
        - Fix another rendezvous cache unit test that was triggering an
          underflow on the global rend cache allocation. Fixes bug 40126;
          bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.4.5.1-alpha):
        - Fix compiler warnings that would occur when building with
          "--enable-all-bugs-are-fatal" and "--disable-module-relay" at the
          same time. Fixes bug 40129; bugfix on 0.4.4.1-alpha.
        - Resolve a compilation warning that could occur in
          test_connection.c. Fixes bug 40113; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.5.1-alpha):
        - Remove a debug logging statement that uselessly spammed the logs.
          Fixes bug 40135; bugfix on 0.3.5.0-alpha.
    
      o Minor bugfixes (relay configuration, crash, backport from 0.4.5.1-alpha):
        - Avoid a fatal assert() when failing to create a listener
          connection for an address that was in use. Fixes bug 40073; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (v2 onion services, backport from 0.4.5.1-alpha):
        - For HSFETCH commands on v2 onion services addresses, check the
          length of bytes decoded, not the base32 length. Fixes bug 34400;
          bugfix on 0.4.1.1-alpha. Patch by Neel Chauhan.
    
    
    Changes in version 0.4.3.7 - 2020-11-12
      Tor 0.4.3.7 backports several bugfixes from later releases. It
      includes a fix for TROVE-2020-005, a security issue that could be
      used, under certain cases, by an adversary to observe traffic patterns
      on a limited number of circuits intended for a different relay.
    
      Please be aware that support for the 0.4.3.x series will end on 15
      February 2021. Please upgrade to 0.4.4.x or 0.4.5.x before then, or
      downgrade to 0.3.5.x, which will be supported until at least 1
      February 2022.
    
      o Major features (fallback directory list, backport form 0.4.4.3-alpha):
        - Replace the 148 fallback directories originally included in Tor
          0.4.1.4-rc (of which around 105 are still functional) with a list
          of 144 fallbacks generated in July 2020. Closes ticket 40061.
    
      o Major bugfixes (security, backport from 0.4.5.1-alpha):
        - When completing a channel, relays now check more thoroughly to
          make sure that it matches any pending circuits before attaching
          those circuits. Previously, address correctness and Ed25519
          identities were not checked in this case, but only when extending
          circuits on an existing channel. Fixes bug 40080; bugfix on
          0.2.7.2-alpha. Resolves TROVE-2020-005.
    
      o Major bugfixes (NSS, backport from 0.4.4.3-alpha):
        - When running with NSS enabled, make sure that NSS knows to expect
          nonblocking sockets. Previously, we set our TCP sockets as
          nonblocking, but did not tell NSS, which in turn could lead to
          unexpected blocking behavior. Fixes bug 40035; bugfix
          on 0.3.5.1-alpha.
    
      o Minor features (security, backport from 0.4.4.4-rc):
        - Channels using obsolete versions of the Tor link protocol are no
          longer allowed to circumvent address-canonicity checks. (This is
          only a minor issue, since such channels have no way to set ed25519
          keys, and therefore should always be rejected for circuits that
          specify ed25519 identities.) Closes ticket 40081.
    
      o Minor features (subprotocol versions, backport from 0.4.5.1-alpha):
        - Tor no longer allows subprotocol versions larger than 63.
          Previously version numbers up to UINT32_MAX were allowed, which
          significantly complicated our code. Implements proposal 318;
          closes ticket 40133.
    
      o Minor features (tests, backport from 0.4.4.5):
        - Our "make check" target now runs the unit tests in 8 parallel
          chunks. Doing this speeds up hardened CI builds by more than a
          factor of two. Closes ticket 40098.
    
      o Minor features (tests, v2 onion services, backport from 0.4.5.1-alpha):
        - Fix a rendezvous cache unit test that was triggering an underflow
          on the global rend cache allocation. Fixes bug 40125; bugfix
          on 0.2.8.1-alpha.
        - Fix another rendezvous cache unit test that was triggering an
          underflow on the global rend cache allocation. Fixes bug 40126;
          bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (correctness, buffers, backport from 0.4.4.4-rc):
        - Fix a correctness bug that could cause an assertion failure if we
          ever tried using the buf_move_all() function with an empty input
          buffer. As far as we know, no released versions of Tor do this.
          Fixes bug 40076; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.5.1-alpha):
        - Remove a debug logging statement that uselessly spammed the logs.
          Fixes bug 40135; bugfix on 0.3.5.0-alpha.
    
      o Minor bugfixes (rate limiting, bridges, pluggable transports, backport from 0.4.4.4-rc):
        - On a bridge, treat all connections from an ExtORPort as remote by
          default for the purposes of rate-limiting. Previously, bridges
          would treat the connection as local unless they explicitly
          received a "USERADDR" command. ExtORPort connections still count
          as local if there is a USERADDR command with an explicit local
          address. Fixes bug 33747; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (relay configuration, crash, backport from 0.4.5.1-alpha):
        - Avoid a fatal assert() when failing to create a listener
          connection for an address that was in use. Fixes bug 40073; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (relay, usability, backport from 0.4.4.3-alpha):
        - Adjust the rules for when to warn about having too many
          connections to other relays. Previously we'd tolerate up to 1.5
          connections per relay on average. Now we tolerate more connections
          for directory authorities, and raise the number of total
          connections we need to see before we warn. Fixes bug 33880; bugfix
          on 0.3.1.1-alpha.
    
      o Minor bugfixes (tests, 0.4.4.5):
        - Fix the behavior of the rend_cache/clean_v2_descs_as_dir when run
          on its own. Previously, it would exit with an error. Fixes bug
          40099; bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (v2 onion services, backport from 0.4.5.1-alpha):
        - For HSFETCH commands on v2 onion services addresses, check the
          length of bytes decoded, not the base32 length. Fixes bug 34400;
          bugfix on 0.4.1.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (windows, backport from 0.4.4.4-rc):
        - Fix a bug that prevented Tor from starting if its log file grew
          above 2GB. Fixes bug 31036; bugfix on 0.2.1.8-alpha.
    
      o Deprecated features (onion service v2, backport form 0.4.4.2-alpha):
        - Add a deprecation warning for version 2 onion services. Closes
          ticket 40003.
    
      o Removed features (backport from 0.4.4.3-alpha):
        - Our "check-local" test target no longer tries to use the
          Coccinelle semantic patching tool parse all the C files. While it
          is a good idea to try to make sure Coccinelle works on our C
          before we run a Coccinelle patch, doing so on every test run has
          proven to be disruptive. You can still run this tool manually with
          "make check-cocci". Closes ticket 40030. ticket 40030.
    
    
    Changes in version 0.3.5.12 - 2020-11-12
      Tor 0.4.3.7 backports several bugfixes from later releases. It
      includes a fix for TROVE-2020-005, a security issue that could be
      used, under certain cases, by an adversary to observe traffic patterns
      on a limited number of circuits intended for a different relay.
    
      o Major features (fallback directory list, backport form 0.4.4.3-alpha):
        - Replace the 148 fallback directories originally included in Tor
          0.4.1.4-rc (of which around 105 are still functional) with a list
          of 144 fallbacks generated in July 2020. Closes ticket 40061.
    
      o Major bugfixes (security, backport from 0.4.5.1-alpha):
        - When completing a channel, relays now check more thoroughly to
          make sure that it matches any pending circuits before attaching
          those circuits. Previously, address correctness and Ed25519
          identities were not checked in this case, but only when extending
          circuits on an existing channel. Fixes bug 40080; bugfix on
          0.2.7.2-alpha. Resolves TROVE-2020-005.
    
      o Major bugfixes (NSS, backport from 0.4.4.3-alpha):
        - When running with NSS enabled, make sure that NSS knows to expect
          nonblocking sockets. Previously, we set our TCP sockets as
          nonblocking, but did not tell NSS, which in turn could lead to
          unexpected blocking behavior. Fixes bug 40035; bugfix
          on 0.3.5.1-alpha.
    
      o Minor features (security, backport from 0.4.4.4-rc):
        - Channels using obsolete versions of the Tor link protocol are no
          longer allowed to circumvent address-canonicity checks. (This is
          only a minor issue, since such channels have no way to set ed25519
          keys, and therefore should always be rejected for circuits that
          specify ed25519 identities.) Closes ticket 40081.
    
      o Minor features (debugging, directory system):
        - Don't crash when we find a non-guard with a guard-fraction value
          set. Instead, log a bug warning, in an attempt to figure out how
          this happened. Diagnostic for ticket 32868.
    
      o Minor features (subprotocol versions, backport from 0.4.5.1-alpha):
        - Tor no longer allows subprotocol versions larger than 63.
          Previously version numbers up to UINT32_MAX were allowed, which
          significantly complicated our code. Implements proposal 318;
          closes ticket 40133.
    
      o Minor features (tests, backport from 0.4.4.5):
        - Our "make check" target now runs the unit tests in 8 parallel
          chunks. Doing this speeds up hardened CI builds by more than a
          factor of two. Closes ticket 40098.
    
      o Minor features (tests, v2 onion services, backport from 0.4.5.1-alpha):
        - Fix a rendezvous cache unit test that was triggering an underflow
          on the global rend cache allocation. Fixes bug 40125; bugfix
          on 0.2.8.1-alpha.
        - Fix another rendezvous cache unit test that was triggering an
          underflow on the global rend cache allocation. Fixes bug 40126;
          bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (correctness, buffers, backport from 0.4.4.4-rc):
        - Fix a correctness bug that could cause an assertion failure if we
          ever tried using the buf_move_all() function with an empty input
          buffer. As far as we know, no released versions of Tor do this.
          Fixes bug 40076; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.5.1-alpha):
        - Remove a debug logging statement that uselessly spammed the logs.
          Fixes bug 40135; bugfix on 0.3.5.0-alpha.
    
      o Minor bugfixes (rate limiting, bridges, pluggable transports, backport from 0.4.4.4-rc):
        - On a bridge, treat all connections from an ExtORPort as remote by
          default for the purposes of rate-limiting. Previously, bridges
          would treat the connection as local unless they explicitly
          received a "USERADDR" command. ExtORPort connections still count
          as local if there is a USERADDR command with an explicit local
          address. Fixes bug 33747; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (relay configuration, crash, backport from 0.4.5.1-alpha):
        - Avoid a fatal assert() when failing to create a listener
          connection for an address that was in use. Fixes bug 40073; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (relay, usability, backport from 0.4.4.3-alpha):
        - Adjust the rules for when to warn about having too many
          connections to other relays. Previously we'd tolerate up to 1.5
          connections per relay on average. Now we tolerate more connections
          for directory authorities, and raise the number of total
          connections we need to see before we warn. Fixes bug 33880; bugfix
          on 0.3.1.1-alpha.
    
      o Minor bugfixes (relays, backport from 0.4.4.1-alpha):
        - Stop advertising incorrect IPv6 ORPorts in relay and bridge
          descriptors, when the IPv6 port was configured as "auto". Fixes
          bug 32588; bugfix on 0.2.3.9-alpha.
    
      o Minor bugfixes (tests, 0.4.4.5):
        - Fix the behavior of the rend_cache/clean_v2_descs_as_dir when run
          on its own. Previously, it would exit with an error. Fixes bug
          40099; bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (windows, backport from 0.4.4.4-rc):
        - Fix a bug that prevented Tor from starting if its log file grew
          above 2GB. Fixes bug 31036; bugfix on 0.2.1.8-alpha.
    
      o Deprecated features (onion service v2, backport form 0.4.4.2-alpha):
        - Add a deprecation warning for version 2 onion services. Closes
          ticket 40003.
    
    Changes in version 0.4.4.5 - 2020-09-15
      Tor 0.4.4.5 is the first stable release in the 0.4.4.x series. This
      series improves our guard selection algorithms, adds v3 onion balance
      support, improves the amount of code that can be disabled when running
      without relay support, and includes numerous small bugfixes and
      enhancements. It also lays the ground for some IPv6 features that
      we'll be developing more in the next (0.4.5) series.
    
      Per our support policy, we support each stable release series for nine
      months after its first stable release, or three months after the first
      stable release of the next series: whichever is longer. This means
      that 0.4.4.x will be supported until around June 2021--or later, if
      0.4.5.x is later than anticipated.
    
      Note also that support for 0.4.2.x has just ended; support for 0.4.3
      will continue until Feb 15, 2021. We still plan to continue supporting
      0.3.5.x, our long-term stable series, until Feb 2022.
    
      Below are the changes since 0.4.3.6-rc. For a complete list of changes
      since 0.4.4.4-rc, see the ChangeLog file.
    
      o Major features (Proposal 310, performance + security):
        - Implements Proposal 310, "Bandaid on guard selection". Proposal
          310 solves load-balancing issues with older versions of the guard
          selection algorithm, and improves its security. Under this new
          algorithm, a newly selected guard never becomes Primary unless all
          previously sampled guards are unreachable. Implements
          recommendation from 32088. (Proposal 310 is linked to the CLAPS
          project researching optimal client location-aware path selections.
          This project is a collaboration between the UCLouvain Crypto Group,
          the U.S. Naval Research Laboratory, and Princeton University.)
    
      o Major features (fallback directory list):
        - Replace the 148 fallback directories originally included in Tor
          0.4.1.4-rc (of which around 105 are still functional) with a list
          of 144 fallbacks generated in July 2020. Closes ticket 40061.
    
      o Major features (IPv6, relay):
        - Consider IPv6-only EXTEND2 cells valid on relays. Log a protocol
          warning if the IPv4 or IPv6 address is an internal address, and
          internal addresses are not allowed. But continue to use the other
          address, if it is valid. Closes ticket 33817.
        - If a relay can extend over IPv4 and IPv6, and both addresses are
          provided, it chooses between them uniformly at random. Closes
          ticket 33817.
        - Re-use existing IPv6 connections for circuit extends. Closes
          ticket 33817.
        - Relays may extend circuits over IPv6, if the relay has an IPv6
          ORPort, and the client supplies the other relay's IPv6 ORPort in
          the EXTEND2 cell. IPv6 extends will be used by the relay IPv6
          ORPort self-tests in 33222. Closes ticket 33817.
    
      o Major features (v3 onion services):
        - Allow v3 onion services to act as OnionBalance backend instances,
          by using the HiddenServiceOnionBalanceInstance torrc option.
          Closes ticket 32709.
    
      o Major bugfixes (NSS):
        - When running with NSS enabled, make sure that NSS knows to expect
          nonblocking sockets. Previously, we set our TCP sockets as
          nonblocking, but did not tell NSS, which in turn could lead to
          unexpected blocking behavior. Fixes bug 40035; bugfix
          on 0.3.5.1-alpha.
    
      o Major bugfixes (onion services, DoS):
        - Correct handling of parameters for the onion service DoS defense.
          Previously, the consensus parameters for the onion service DoS
          defenses were overwriting the parameters set by the service
          operator using HiddenServiceEnableIntroDoSDefense. Fixes bug
          40109; bugfix on 0.4.2.1-alpha.
    
      o Major bugfixes (stats, onion services):
        - Fix a bug where we were undercounting the Tor network's total
          onion service traffic, by ignoring any traffic originating from
          clients. Now we count traffic from both clients and services.
          Fixes bug 40117; bugfix on 0.2.6.2-alpha.
    
      o Minor features (security):
        - Channels using obsolete versions of the Tor link protocol are no
          longer allowed to circumvent address-canonicity checks. (This is
          only a minor issue, since such channels have no way to set ed25519
          keys, and therefore should always be rejected for circuits that
          specify ed25519 identities.) Closes ticket 40081.
    
      o Minor features (bootstrap reporting):
        - Report more detailed reasons for bootstrap failure when the
          failure happens due to a TLS error. Previously we would just call
          these errors "MISC" when they happened during read, and "DONE"
          when they happened during any other TLS operation. Closes
          ticket 32622.
    
      o Minor features (client-only compilation):
        - Disable more code related to the ext_orport protocol when
          compiling without support for relay mode. Closes ticket 33368.
        - Disable more of our self-testing code when support for relay mode
          is disabled. Closes ticket 33370.
        - Most server-side DNS code is now disabled when building without
          support for relay mode. Closes ticket 33366.
    
      o Minor features (code safety):
        - Check for failures of tor_inet_ntop() and tor_inet_ntoa()
          functions in DNS and IP address processing code, and adjust
          codepaths to make them less likely to crash entire Tor instances.
          Resolves issue 33788.
    
      o Minor features (continuous integration):
        - Run unit-test and integration test (Stem, Chutney) jobs with
          ALL_BUGS_ARE_FATAL macro being enabled on Travis and Appveyor.
          Resolves ticket 32143.
    
      o Minor features (control port):
        - If a ClientName was specified in ONION_CLIENT_AUTH_ADD for an
          onion service, display it when we use ONION_CLIENT_AUTH_VIEW.
          Closes ticket 40089. Patch by Neel Chauhan.
        - Return a descriptive error message from the 'GETINFO status/fresh-
          relay-descs' command on the control port. Previously, we returned
          a generic error of "Error generating descriptor". Closes ticket
          32873. Patch by Neel Chauhan.
    
      o Minor features (defense in depth):
        - Wipe more data from connection address fields before returning
          them to the memory heap. Closes ticket 6198.
    
      o Minor features (denial-of-service memory limiter):
        - Allow the user to configure even lower values for the
          MaxMemInQueues parameter. Relays now enforce a minimum of 64 MB,
          when previously the minimum was 256 MB. On clients, there is no
          minimum. Relays and clients will both warn if the value is set so
          low that Tor is likely to stop working. Closes ticket 24308.
    
      o Minor features (developer tooling):
        - Add a script to help check the alphabetical ordering of option
          names in the manual page. Closes ticket 33339.
        - Refrain from listing all .a files that are generated by the Tor
          build in .gitignore. Add a single wildcard *.a entry that covers
          all of them for present and future. Closes ticket 33642.
        - Add a script ("git-install-tools.sh") to install git hooks and
          helper scripts. Closes ticket 33451.
    
      o Minor features (directory authority):
        - Authorities now recommend the protocol versions that are supported
          by Tor 0.3.5 and later. (Earlier versions of Tor have been
          deprecated since January of this year.) This recommendation will
          cause older clients and relays to give a warning on startup, or
          when they download a consensus directory. Closes ticket 32696.
    
      o Minor features (directory authority, shared random):
        - Refactor more authority-only parts of the shared-random scheduling
          code to reside in the dirauth module, and to be disabled when
          compiling with --disable-module-dirauth. Closes ticket 33436.
    
      o Minor features (directory):
        - Remember the number of bytes we have downloaded for each directory
          purpose while bootstrapping, and while fully bootstrapped. Log
          this information as part of the heartbeat message. Closes
          ticket 32720.
    
      o Minor features (entry guards):
        - Reinstate support for GUARD NEW/UP/DOWN control port events.
          Closes ticket 40001.
    
      o Minor features (IPv6 support):
        - Adds IPv6 support to tor_addr_is_valid(). Adds tests for the above
          changes and tor_addr_is_null(). Closes ticket 33679. Patch
          by MrSquanchee.
        - Allow clients and relays to send dual-stack and IPv6-only EXTEND2
          cells. Parse dual-stack and IPv6-only EXTEND2 cells on relays.
          Closes ticket 33901.
    
      o Minor features (linux seccomp2 sandbox, portability):
        - Allow Tor to build on platforms where it doesn't know how to
          report which syscall caused the linux seccomp2 sandbox to fail.
          This change should make the sandbox code more portable to less
          common Linux architectures. Closes ticket 34382.
        - Permit the unlinkat() syscall, which some Libc implementations use
          to implement unlink(). Closes ticket 33346.
    
      o Minor features (logging):
        - When trying to find our own address, add debug-level logging to
          report the sources of candidate addresses. Closes ticket 32888.
    
      o Minor features (onion service client, SOCKS5):
        - Add 3 new SocksPort ExtendedErrors (F2, F3, F7) that reports back
          new type of onion service connection failures. The semantics of
          these error codes are documented in proposal 309. Closes
          ticket 32542.
    
      o Minor features (onion service v3):
        - If a service cannot upload its descriptor(s), log why at INFO
          level. Closes ticket 33400; bugfix on 0.3.2.1-alpha.
    
      o Minor features (python scripts):
        - Stop assuming that /usr/bin/python exists. Instead of using a
          hardcoded path in scripts that still use Python 2, use
          /usr/bin/env, similarly to the scripts that use Python 3. Fixes
          bug 33192; bugfix on 0.4.2.
    
      o Minor features (testing, architecture):
        - Our test scripts now double-check that subsystem initialization
          order is consistent with the inter-module dependencies established
          by our .may_include files. Implements ticket 31634.
        - Initialize all subsystems at the beginning of our unit test
          harness, to avoid crashes due to uninitialized subsystems. Follow-
          up from ticket 33316.
        - Our "make check" target now runs the unit tests in 8 parallel
          chunks. Doing this speeds up hardened CI builds by more than a
          factor of two. Closes ticket 40098.
    
      o Minor features (v3 onion services):
        - Add v3 onion service status to the dumpstats() call which is
          triggered by a SIGUSR1 signal. Previously, we only did v2 onion
          services. Closes ticket 24844. Patch by Neel Chauhan.
    
      o Minor features (windows):
        - Add support for console control signals like Ctrl+C in Windows.
          Closes ticket 34211. Patch from Damon Harris (TheDcoder).
    
      o Minor bugfixes (control port, onion service):
        - Consistently use 'address' in "Invalid v3 address" response to
          ONION_CLIENT_AUTH commands. Previously, we would sometimes say
          'addr'. Fixes bug 40005; bugfix on 0.4.3.1-alpha.
    
      o Minor bugfixes (correctness, buffers):
        - Fix a correctness bug that could cause an assertion failure if we
          ever tried using the buf_move_all() function with an empty input
          buffer. As far as we know, no released versions of Tor do this.
          Fixes bug 40076; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (directory authorities):
        - Directory authorities now reject votes that arrive too late. In
          particular, once an authority has started fetching missing votes,
          it no longer accepts new votes posted by other authorities. This
          change helps prevent a consensus split, where only some authorities
          have the late vote. Fixes bug 4631; bugfix on 0.2.0.5-alpha.
    
      o Minor bugfixes (git scripts):
        - Stop executing the checked-out pre-commit hook from the pre-push
          hook. Instead, execute the copy in the user's git directory. Fixes
          bug 33284; bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (initialization):
        - Initialize the subsystems in our code in an order more closely
          corresponding to their dependencies, so that every system is
          initialized before the ones that (theoretically) depend on it.
          Fixes bug 33316; bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (IPv4, relay):
        - Check for invalid zero IPv4 addresses and ports when sending and
          receiving extend cells. Fixes bug 33900; bugfix on 0.2.4.8-alpha.
    
      o Minor bugfixes (IPv6, relay):
        - Consider IPv6 addresses when checking if a connection is
          canonical. In 17604, relays assumed that a remote relay could
          consider an IPv6 connection canonical, but did not set the
          canonical flag on their side of the connection. Fixes bug 33899;
          bugfix on 0.3.1.1-alpha.
        - Log IPv6 addresses on connections where this relay is the
          responder. Previously, responding relays would replace the remote
          IPv6 address with the IPv4 address from the consensus. Fixes bug
          33899; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (linux seccomp2 sandbox):
        - Fix a regression on sandboxing rules for the openat() syscall. The
          fix for bug 25440 fixed the problem on systems with glibc >= 2.27
          but broke with versions of glibc. We now choose a rule based on
          the glibc version. Patch from Daniel Pinto. Fixes bug 27315;
          bugfix on 0.3.5.11.
        - Makes the seccomp sandbox allow the correct syscall for opendir
          according to the running glibc version. This fixes crashes when
          reloading torrc with sandbox enabled when running on glibc 2.15 to
          2.21 and 2.26. Patch from Daniel Pinto. Fixes bug 40020; bugfix
          on 0.3.5.11.
    
      o Minor bugfixes (logging, testing):
        - Make all of tor's assertion macros support the ALL_BUGS_ARE_FATAL
          and DISABLE_ASSERTS_IN_UNIT_TESTS debugging modes. (IF_BUG_ONCE()
          used to log a non-fatal warning, regardless of the debugging
          mode.) Fixes bug 33917; bugfix on 0.2.9.1-alpha.
        - Remove surprising empty line in the INFO-level log about circuit
          build timeout. Fixes bug 33531; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (mainloop):
        - Better guard against growing a buffer past its maximum 2GB in
          size. Fixes bug 33131; bugfix on 0.3.0.4-rc.
    
      o Minor bugfixes (onion service v3 client):
        - Remove a BUG() warning that could occur naturally. Fixes bug
          34087; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion service, logging):
        - Fix a typo in a log message PublishHidServDescriptors is set to 0.
          Fixes bug 33779; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion services v3):
        - Avoid a non-fatal assertion failure in certain edge-cases when
          opening an intro circuit as a client. Fixes bug 34084; bugfix
          on 0.3.2.1-alpha.
    
      o Minor bugfixes (protocol versions):
        - Sort tor's supported protocol version lists, as recommended by the
          tor directory specification. Fixes bug 33285; bugfix
          on 0.4.0.1-alpha.
    
      o Minor bugfixes (rate limiting, bridges, pluggable transports):
        - On a bridge, treat all connections from an ExtORPort as remote by
          default for the purposes of rate-limiting. Previously, bridges
          would treat the connection as local unless they explicitly
          received a "USERADDR" command. ExtORPort connections still count
          as local if there is a USERADDR command with an explicit local
          address. Fixes bug 33747; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (refactoring):
        - Lift circuit_build_times_disabled() out of the
          circuit_expire_building() loop, to save CPU time when there are
          many circuits open. Fixes bug 33977; bugfix on 0.3.5.9.
    
      o Minor bugfixes (relay, self-testing):
        - When starting up as a relay, if we haven't been able to verify
          that we're reachable, only launch reachability tests at most once
          a minute. Previously, we had been launching tests up to once a
          second, which was needlessly noisy. Fixes bug 40083; bugfix
          on 0.2.8.1-alpha.
    
      o Minor bugfixes (relay, usability):
        - Adjust the rules for when to warn about having too many
          connections to other relays. Previously we'd tolerate up to 1.5
          connections per relay on average. Now we tolerate more connections
          for directory authorities, and raise the number of total
          connections we need to see before we warn. Fixes bug 33880; bugfix
          on 0.3.1.1-alpha.
    
      o Minor bugfixes (SOCKS, onion service client):
        - Detect v3 onion service addresses of the wrong length when
          returning the F6 ExtendedErrors code. Fixes bug 33873; bugfix
          on 0.4.3.1-alpha.
    
      o Minor bugfixes (tests):
        - Fix the behavior of the rend_cache/clean_v2_descs_as_dir when run
          on its own. Previously, it would exit with an error. Fixes bug
          40099; bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (v3 onion services):
        - Remove a BUG() warning that could trigger in certain unlikely
          edge-cases. Fixes bug 34086; bugfix on 0.3.2.1-alpha.
        - Remove a BUG() that was causing a stacktrace when a descriptor
          changed at an unexpected time. Fixes bug 28992; bugfix
          on 0.3.2.1-alpha.
    
      o Minor bugfixes (windows):
        - Fix a bug that prevented Tor from starting if its log file grew
          above 2GB. Fixes bug 31036; bugfix on 0.2.1.8-alpha.
    
      o Code simplification and refactoring:
        - Define and use a new constant TOR_ADDRPORT_BUF_LEN which is like
          TOR_ADDR_BUF_LEN but includes enough space for an IP address,
          brackets, separating colon, and port number. Closes ticket 33956.
          Patch by Neel Chauhan.
        - Merge the orconn and ocirc events into the "core" subsystem, which
          manages or connections and origin circuits. Previously they were
          isolated in subsystems of their own.
        - Move LOG_PROTOCOL_WARN to app/config. Resolves a dependency
          inversion. Closes ticket 33633.
        - Move the circuit extend code to the relay module. Split the
          circuit extend function into smaller functions. Closes
          ticket 33633.
        - Rewrite port_parse_config() to use the default port flags from
          port_cfg_new(). Closes ticket 32994. Patch by MrSquanchee.
        - Updated comments in 'scheduler.c' to reflect old code changes, and
          simplified the scheduler channel state change code. Closes
          ticket 33349.
        - Refactor configuration parsing to use the new config subsystem
          code. Closes ticket 33014.
        - Move a series of functions related to address resolving into their
          own files. Closes ticket 33789.
    
      o Documentation:
        - Replace most http:// URLs in our code and documentation with
          https:// URLs. (We have left unchanged the code in src/ext/, and
          the text in LICENSE.) Closes ticket 31812. Patch from Jeremy Rand.
        - Document the limitations of using %include on config files with
          seccomp sandbox enabled. Fixes documentation bug 34133; bugfix on
          0.3.1.1-alpha. Patch by Daniel Pinto.
    
      o Removed features:
        - Our "check-local" test target no longer tries to use the
          Coccinelle semantic patching tool parse all the C files. While it
          is a good idea to try to make sure Coccinelle works on our C
          before we run a Coccinelle patch, doing so on every test run has
          proven to be disruptive. You can still run this tool manually with
          "make check-cocci". Closes ticket 40030.
        - Remove the ClientAutoIPv6ORPort option. This option attempted to
          randomly choose between IPv4 and IPv6 for client connections, and
          wasn't a true implementation of Happy Eyeballs. Often, this option
          failed on IPv4-only or IPv6-only connections. Closes ticket 32905.
          Patch by Neel Chauhan.
        - Stop shipping contrib/dist/rc.subr file, as it is not being used
          on FreeBSD anymore. Closes issue 31576.
    
      o Testing:
        - Add a basic IPv6 test to "make test-network". This test only runs
          when the local machine has an IPv6 stack. Closes ticket 33300.
        - Add test-network-ipv4 and test-network-ipv6 jobs to the Makefile.
          These jobs run the IPv4-only and dual-stack chutney flavours from
          test-network-all. Closes ticket 33280.
        - Remove a redundant distcheck job. Closes ticket 33194.
        - Run the test-network-ipv6 Makefile target in the Travis CI IPv6
          chutney job. This job runs on macOS, so it's a bit slow. Closes
          ticket 33303.
        - Sort the Travis jobs in order of speed. Putting the slowest jobs
          first takes full advantage of Travis job concurrency. Closes
          ticket 33194.
        - Stop allowing the Chutney IPv6 Travis job to fail. This job was
          previously configured to fast_finish (which requires
          allow_failure), to speed up the build. Closes ticket 33195.
        - Test v3 onion services to tor's mixed IPv4 chutney network. And
          add a mixed IPv6 chutney network. These networks are used in the
          test-network-all, test-network-ipv4, and test-network-ipv6 make
          targets. Closes ticket 33334.
        - Use the "bridges+hs-v23" chutney network flavour in "make test-
          network". This test requires a recent version of chutney (mid-
          February 2020). Closes ticket 28208.
        - When a Travis chutney job fails, use chutney's new "diagnostics.sh"
          tool to produce detailed diagnostic output. Closes ticket 32792.
    
      o Deprecated features (onion service v2):
        - Add a deprecation warning for version 2 onion services. Closes
          ticket 40003.
    
      o Documentation (manual page):
        - Add cross reference links and a table of contents to the HTML tor
          manual page. Closes ticket 33369. Work by Swati Thacker as part of
          Google Season of Docs.
        - Alphabetize the Denial of Service Mitigation Options, Directory
          Authority Server Options, Hidden Service Options, and Testing
          Network Options sections of the tor(1) manual page. Closes ticket
          33275. Work by Swati Thacker as part of Google Season of Docs.
        - Refrain from mentioning nicknames in manpage section for MyFamily
          torrc option. Resolves issue 33417.
        - Updated the options set by TestingTorNetwork in the manual page.
          Closes ticket 33778.
    
    
    Changes in version 0.3.5.11 - 2020-07-09
      Tor 0.3.5.11 backports fixes from later tor releases, including several
      usability, portability, and reliability fixes.
    
      This release also fixes TROVE-2020-001, a medium-severity denial of
      service vulnerability affecting all versions of Tor when compiled with
      the NSS encryption library. (This is not the default configuration.)
      Using this vulnerability, an attacker could cause an affected Tor
      instance to crash remotely. This issue is also tracked as CVE-2020-
      15572. Anybody running a version of Tor built with the NSS library
      should upgrade to 0.3.5.11, 0.4.2.8, 0.4.3.6, or 0.4.4.2-alpha
      or later.
    
      o Major bugfixes (NSS, security, backport from 0.4.4.2-alpha):
        - Fix a crash due to an out-of-bound memory access when Tor is
          compiled with NSS support. Fixes bug 33119; bugfix on
          0.3.5.1-alpha. This issue is also tracked as TROVE-2020-001
          and CVE-2020-15572.
    
      o Major bugfixes (DoS defenses, bridges, pluggable transport, backport from 0.4.3.4-rc):
        - Fix a bug that was preventing DoS defenses from running on bridges
          with a pluggable transport. Previously, the DoS subsystem was not
          given the transport name of the client connection, thus failed to
          find the GeoIP cache entry for that client address. Fixes bug
          33491; bugfix on 0.3.3.2-alpha.
    
      o Minor features (testing, backport from 0.4.3.4-rc):
        - The unit tests now support a "TOR_SKIP_TESTCASES" environment
          variable to specify a list of space-separated test cases that
          should not be executed. We will use this to disable certain tests
          that are failing on Appveyor because of mismatched OpenSSL
          libraries. Part of ticket 33643.
    
      o Minor bugfix (CI, Windows, backport from 0.4.4.2-alpha):
        - Use the correct 64-bit printf format when compiling with MINGW on
          Appveyor. Fixes bug 40026; bugfix on 0.3.5.5-alpha.
    
      o Minor bugfix (relay, configuration, backport from 0.4.3.3-alpha):
        - Warn if the ContactInfo field is not set, and tell the relay
          operator that not having a ContactInfo field set might cause their
          relay to get rejected in the future. Fixes bug 33361; bugfix
          on 0.1.1.10-alpha.
    
      o Minor bugfixes (client performance, backport from 0.4.4.1-alpha):
        - Resume use of preemptively-built circuits when UseEntryGuards is set
          to 0. We accidentally disabled this feature with that config
          setting, leading to slower load times. Fixes bug 34303; bugfix
          on 0.3.3.2-alpha.
    
      o Minor bugfixes (compiler compatibility, backport from 0.4.3.5):
        - Avoid compiler warnings from Clang 10 related to the use of GCC-
          style "/* falls through */" comments. Both Clang and GCC allow
          __attribute__((fallthrough)) instead, so that's what we're using
          now. Fixes bug 34078; bugfix on 0.3.1.3-alpha.
    
      o Minor bugfixes (compiler warnings, backport from 0.4.4.2-alpha):
        - Fix a compiler warning on platforms with 32-bit time_t values.
          Fixes bug 40028; bugfix on 0.3.2.8-rc.
    
      o Minor bugfixes (embedded Tor, backport from 0.4.3.1-alpha):
        - When starting Tor any time after the first time in a process,
          register the thread in which it is running as the main thread.
          Previously, we only did this on Windows, which could lead to bugs
          like 23081 on non-Windows platforms. Fixes bug 32884; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (key portability, backport from 0.4.3.4-rc):
        - When reading PEM-encoded key data, tolerate CRLF line-endings even
          if we are not running on Windows. Previously, non-Windows hosts
          would reject these line-endings in certain positions, making
          certain key files hard to move from one host to another. Fixes bug
          33032; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.4.2-alpha):
        - Downgrade a noisy log message that could occur naturally when
          receiving an extrainfo document that we no longer want. Fixes bug
          16016; bugfix on 0.2.6.3-alpha.
    
      o Minor bugfixes (onion service v3, client, backport from 0.4.3.3-alpha):
        - Remove a BUG() warning that would cause a stack trace if an onion
          service descriptor was freed while we were waiting for a
          rendezvous circuit to complete. Fixes bug 28992; bugfix
          on 0.3.2.1-alpha.
    
      o Testing (CI, backport from 0.4.3.4-rc):
        - In our Appveyor Windows CI, copy required DLLs to test and app
          directories, before running tor's tests. This ensures that tor.exe
          and test*.exe use the correct version of each DLL. This fix is not
          required, but we hope it will avoid DLL search issues in future.
          Fixes bug 33673; bugfix on 0.3.4.2-alpha.
        - On Appveyor, skip the crypto/openssl_version test, which is
          failing because of a mismatched library installation. Fix
          for 33643.
    
    
    Changes in version 0.4.2.8 - 2020-07-09
      Tor 0.4.2.8 backports various fixes from later releases, including
      several that affect usability and portability.
    
      This release also fixes TROVE-2020-001, a medium-severity denial of
      service vulnerability affecting all versions of Tor when compiled with
      the NSS encryption library. (This is not the default configuration.)
      Using this vulnerability, an attacker could cause an affected Tor
      instance to crash remotely. This issue is also tracked as CVE-2020-
      15572. Anybody running a version of Tor built with the NSS library
      should upgrade to 0.3.5.11, 0.4.2.8, 0.4.3.6, or 0.4.4.2-alpha
      or later.
    
      o Major bugfixes (NSS, security, backport from 0.4.4.2-alpha):
        - Fix a crash due to an out-of-bound memory access when Tor is
          compiled with NSS support. Fixes bug 33119; bugfix on
          0.3.5.1-alpha. This issue is also tracked as TROVE-2020-001
          and CVE-2020-15572.
    
      o Major bugfixes (DoS defenses, bridges, pluggable transport, backport from 0.4.3.4-rc):
        - Fix a bug that was preventing DoS defenses from running on bridges
          with a pluggable transport. Previously, the DoS subsystem was not
          given the transport name of the client connection, thus failed to
          find the GeoIP cache entry for that client address. Fixes bug
          33491; bugfix on 0.3.3.2-alpha.
    
      o Minor feature (sendme, flow control, backport form 0.4.3.4-rc):
        - Default to sending SENDME version 1 cells. (Clients are already
          sending these, because of a consensus parameter telling them to do
          so: this change only affects what clients would do if the
          consensus didn't contain a recommendation.) Closes ticket 33623.
    
      o Minor features (diagnostic, backport from 0.4.3.3-alpha):
        - Improve assertions and add some memory-poisoning code to try to
          track down possible causes of a rare crash (32564) in the EWMA
          code. Closes ticket 33290.
    
      o Minor features (testing, backport from 0.4.3.4-rc):
        - The unit tests now support a "TOR_SKIP_TESTCASES" environment
          variable to specify a list of space-separated test cases that
          should not be executed. We will use this to disable certain tests
          that are failing on Appveyor because of mismatched OpenSSL
          libraries. Part of ticket 33643.
    
      o Minor bugfix (CI, Windows, backport from 0.4.4.2-alpha):
        - Use the correct 64-bit printf format when compiling with MINGW on
          Appveyor. Fixes bug 40026; bugfix on 0.3.5.5-alpha.
    
      o Minor bugfix (relay, configuration, backport from 0.4.3.3-alpha):
        - Warn if the ContactInfo field is not set, and tell the relay
          operator that not having a ContactInfo field set might cause their
          relay to get rejected in the future. Fixes bug 33361; bugfix
          on 0.1.1.10-alpha.
    
      o Minor bugfixes (client performance, backport from 0.4.4.1-alpha):
        - Resume use of preemptively-built circuits when UseEntryGuards is set
          to 0. We accidentally disabled this feature with that config
          setting, leading to slower load times. Fixes bug 34303; bugfix
          on 0.3.3.2-alpha.
    
      o Minor bugfixes (compiler compatibility, backport from 0.4.3.5):
        - Avoid compiler warnings from Clang 10 related to the use of GCC-
          style "/* falls through */" comments. Both Clang and GCC allow
          __attribute__((fallthrough)) instead, so that's what we're using
          now. Fixes bug 34078; bugfix on 0.3.1.3-alpha.
        - Fix compilation warnings with GCC 10.0.1. Fixes bug 34077; bugfix
          on 0.4.0.3-alpha.
    
      o Minor bugfixes (compiler warnings, backport from 0.4.4.2-alpha):
        - Fix a compiler warning on platforms with 32-bit time_t values.
          Fixes bug 40028; bugfix on 0.3.2.8-rc.
    
      o Minor bugfixes (controller protocol, backport from 0.4.3.2-alpha):
        - When receiving "ACTIVE" or "DORMANT" signals on the control port,
          report them as SIGNAL events. Previously we would log a bug
          warning. Fixes bug 33104; bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (embedded Tor, backport from 0.4.3.1-alpha):
        - When starting Tor any time after the first time in a process,
          register the thread in which it is running as the main thread.
          Previously, we only did this on Windows, which could lead to bugs
          like 23081 on non-Windows platforms. Fixes bug 32884; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (key portability, backport from 0.4.3.4-rc):
        - When reading PEM-encoded key data, tolerate CRLF line-endings even
          if we are not running on Windows. Previously, non-Windows hosts
          would reject these line-endings in certain positions, making
          certain key files hard to move from one host to another. Fixes bug
          33032; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.3.2-rc):
        - When logging a bug, do not say "Future instances of this warning
          will be silenced" unless we are actually going to silence them.
          Previously we would say this whenever a BUG() check failed in the
          code. Fixes bug 33095; bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.3.4-rc):
        - Flush stderr, stdout, and file logs during shutdown, if supported
          by the OS. This change helps make sure that any final logs are
          recorded. Fixes bug 33087; bugfix on 0.4.1.6.
    
      o Minor bugfixes (logging, backport from 0.4.4.2-alpha):
        - Downgrade a noisy log message that could occur naturally when
          receiving an extrainfo document that we no longer want. Fixes bug
          16016; bugfix on 0.2.6.3-alpha.
    
      o Minor bugfixes (onion service v3, client, backport from 0.4.3.3-alpha):
        - Remove a BUG() warning that would cause a stack trace if an onion
          service descriptor was freed while we were waiting for a
          rendezvous circuit to complete. Fixes bug 28992; bugfix
          on 0.3.2.1-alpha.
    
      o Testing (CI, backport from 0.4.3.4-rc):
        - In our Appveyor Windows CI, copy required DLLs to test and app
          directories, before running tor's tests. This ensures that tor.exe
          and test*.exe use the correct version of each DLL. This fix is not
          required, but we hope it will avoid DLL search issues in future.
          Fixes bug 33673; bugfix on 0.3.4.2-alpha.
        - On Appveyor, skip the crypto/openssl_version test, which is
          failing because of a mismatched library installation. Fix
          for 33643.
    
    
    Changes in version 0.4.3.6 - 2020-07-09
      Tor 0.4.3.6 backports several bugfixes from later releases, including
      some affecting usability.
    
      This release also fixes TROVE-2020-001, a medium-severity denial of
      service vulnerability affecting all versions of Tor when compiled with
      the NSS encryption library. (This is not the default configuration.)
      Using this vulnerability, an attacker could cause an affected Tor
      instance to crash remotely. This issue is also tracked as CVE-2020-
      15572. Anybody running a version of Tor built with the NSS library
      should upgrade to 0.3.5.11, 0.4.2.8, 0.4.3.6, or 0.4.4.2-alpha
      or later.
    
      o Major bugfixes (NSS, security, backport from 0.4.4.2-alpha):
        - Fix a crash due to an out-of-bound memory access when Tor is
          compiled with NSS support. Fixes bug 33119; bugfix on
          0.3.5.1-alpha. This issue is also tracked as TROVE-2020-001
          and CVE-2020-15572.
    
      o Minor bugfix (CI, Windows, backport from 0.4.4.2-alpha):
        - Use the correct 64-bit printf format when compiling with MINGW on
          Appveyor. Fixes bug 40026; bugfix on 0.3.5.5-alpha.
    
      o Minor bugfixes (client performance, backport from 0.4.4.1-alpha):
        - Resume use of preemptively-built circuits when UseEntryGuards is set
          to 0. We accidentally disabled this feature with that config
          setting, leading to slower load times. Fixes bug 34303; bugfix
          on 0.3.3.2-alpha.
    
      o Minor bugfixes (compiler warnings, backport from 0.4.4.2-alpha):
        - Fix a compiler warning on platforms with 32-bit time_t values.
          Fixes bug 40028; bugfix on 0.3.2.8-rc.
    
      o Minor bugfixes (linux seccomp sandbox, nss, backport from 0.4.4.1-alpha):
        - Fix a startup crash when tor is compiled with --enable-nss and
          sandbox support is enabled. Fixes bug 34130; bugfix on
          0.3.5.1-alpha. Patch by Daniel Pinto.
    
      o Minor bugfixes (logging, backport from 0.4.4.2-alpha):
        - Downgrade a noisy log message that could occur naturally when
          receiving an extrainfo document that we no longer want. Fixes bug
          16016; bugfix on 0.2.6.3-alpha.
    
      o Minor bugfixes (manual page, backport from 0.4.4.1-alpha):
        - Update the man page to reflect that MinUptimeHidServDirectoryV2
          defaults to 96 hours. Fixes bug 34299; bugfix on 0.2.6.3-alpha.
    
      o Minor bugfixes (onion service v3, backport from 0.4.4.1-alpha):
        - Prevent an assert() that would occur when cleaning the client
          descriptor cache, and attempting to close circuits for a non-
          decrypted descriptor (lacking client authorization). Fixes bug
          33458; bugfix on 0.4.2.1-alpha.
    
      o Minor bugfixes (portability, backport from 0.4.4.1-alpha):
        - Fix a portability error in the configure script, where we were
          using "==" instead of "=". Fixes bug 34233; bugfix on 0.4.3.5.
    
      o Minor bugfixes (relays, backport from 0.4.4.1-alpha):
        - Stop advertising incorrect IPv6 ORPorts in relay and bridge
          descriptors, when the IPv6 port was configured as "auto". Fixes
          bug 32588; bugfix on 0.2.3.9-alpha.
    
      o Documentation (backport from 0.4.4.1-alpha):
        - Fix several doxygen warnings related to imbalanced groups. Closes
          ticket 34255.
    
    
    Changes in version 0.4.3.5 - 2020-05-15
      Tor 0.4.3.5 is the first stable release in the 0.4.3.x series. This
      series adds support for building without relay code enabled, and
      implements functionality needed for OnionBalance with v3 onion
      services. It includes significant refactoring of our configuration and
      controller functionality, and fixes numerous smaller bugs and
      performance issues.
    
      Per our support policy, we support each stable release series for nine
      months after its first stable release, or three months after the first
      stable release of the next series: whichever is longer. This means
      that 0.4.3.x will be supported until around February 2021--later, if
      0.4.4.x is later than anticipated.
    
      Note also that support for 0.4.1.x is about to end on May 20 of this
      year; 0.4.2.x will be supported until September 15. We still plan to
      continue supporting 0.3.5.x, our long-term stable series, until
      Feb 2022.
    
      Below are the changes since 0.4.2.6. For a list of only the changes
      since 0.4.3.4-rc, see the ChangeLog file.
    
      o New system requirements:
        - When building Tor, you now need to have Python 3 in order to run
          the integration tests. (Python 2 is officially unsupported
          upstream, as of 1 Jan 2020.) Closes ticket 32608.
    
      o Major features (build system):
        - The relay code can now be disabled using the --disable-module-relay
          configure option. When this option is set, we also disable the
          dirauth module. Closes ticket 32123.
        - When Tor is compiled --disable-module-relay, we also omit the code
          used to act as a directory cache. Closes ticket 32487.
    
      o Major features (directory authority, ed25519):
        - Add support for banning a relay's ed25519 keys in the approved-
          routers file. This will help us migrate away from RSA keys in the
          future. Previously, only RSA keys could be banned in approved-
          routers. Resolves ticket 22029. Patch by Neel Chauhan.
    
      o Major features (onion services):
        - New control port commands to manage client-side onion service
          authorization credentials. The ONION_CLIENT_AUTH_ADD command adds
          a credential, ONION_CLIENT_AUTH_REMOVE deletes a credential, and
          ONION_CLIENT_AUTH_VIEW lists the credentials. Closes ticket 30381.
        - Introduce a new SocksPort flag, ExtendedErrors, to support more
          detailed error codes in information for applications that support
          them. Closes ticket 30382; implements proposal 304.
    
      o Major features (proxy):
        - In addition to its current supported proxy types (HTTP CONNECT,
          SOCKS4, and SOCKS5), Tor can now make its OR connections through a
          HAProxy server. A new torrc option was added to specify the
          address/port of the server: TCPProxy <protocol> <host>:<port>.
          Currently the only supported protocol for the option is haproxy.
          Closes ticket 31518. Patch done by Suphanat Chunhapanya (haxxpop).
    
      o Major bugfixes (security, denial-of-service):
        - Fix a denial-of-service bug that could be used by anyone to
          consume a bunch of CPU on any Tor relay or authority, or by
          directories to consume a bunch of CPU on clients or hidden
          services. Because of the potential for CPU consumption to
          introduce observable timing patterns, we are treating this as a
          high-severity security issue. Fixes bug 33119; bugfix on
          0.2.1.5-alpha. Found by OSS-Fuzz. We are also tracking this issue
          as TROVE-2020-002 and CVE-2020-10592.
    
      o Major bugfixes (circuit padding, memory leak):
        - Avoid a remotely triggered memory leak in the case that a circuit
          padding machine is somehow negotiated twice on the same circuit.
          Fixes bug 33619; bugfix on 0.4.0.1-alpha. Found by Tobias Pulls.
          This is also tracked as TROVE-2020-004 and CVE-2020-10593.
    
      o Major bugfixes (directory authority):
        - Directory authorities will now send a 503 (not enough bandwidth)
          code to clients when under bandwidth pressure. Known relays and
          other authorities will always be answered regardless of the
          bandwidth situation. Fixes bug 33029; bugfix on 0.1.2.5-alpha.
    
      o Major bugfixes (DoS defenses, bridges, pluggable transport):
        - Fix a bug that was preventing DoS defenses from running on bridges
          with a pluggable transport. Previously, the DoS subsystem was not
          given the transport name of the client connection, thus failed to
          find the GeoIP cache entry for that client address. Fixes bug
          33491; bugfix on 0.3.3.2-alpha.
    
      o Major bugfixes (networking):
        - Correctly handle IPv6 addresses in SOCKS5 RESOLVE_PTR requests,
          and accept strings as well as binary addresses. Fixes bug 32315;
          bugfix on 0.3.5.1-alpha.
    
      o Major bugfixes (onion service):
        - Report HS circuit failure back into the HS subsystem so we take
          appropriate action with regards to the client introduction point
          failure cache. This improves reachability of onion services, since
          now clients notice failing introduction circuits properly. Fixes
          bug 32020; bugfix on 0.3.2.1-alpha.
    
      o Minor feature (heartbeat, onion service):
        - Add the DoS INTRODUCE2 defenses counter to the heartbeat DoS
          message. Closes ticket 31371.
    
      o Minor feature (sendme, flow control):
        - Default to sending SENDME version 1 cells. (Clients are already
          sending these, because of a consensus parameter telling them to do
          so: this change only affects what clients would do if the
          consensus didn't contain a recommendation.) Closes ticket 33623.
    
      o Minor features (best practices tracker):
        - Practracker now supports a --regen-overbroad option to regenerate
          the exceptions file, but only to revise exceptions to be _less_
          tolerant of best-practices violations. Closes ticket 32372.
    
      o Minor features (configuration validation):
        - Configuration validation can now be done by per-module callbacks,
          rather than a global validation function. This will let us reduce
          the size of config.c and some of its more cumbersome functions.
          Closes ticket 31241.
    
      o Minor features (configuration):
        - If a configured hardware crypto accelerator in AccelName is
          prefixed with "!", Tor now exits when it cannot be found. Closes
          ticket 32406.
        - We now use flag-driven logic to warn about obsolete configuration
          fields, so that we can include their names. In 0.4.2, we used a
          special type, which prevented us from generating good warnings.
          Implements ticket 32404.
    
      o Minor features (configure, build system):
        - Output a list of enabled/disabled features at the end of the
          configure process in a pleasing way. Closes ticket 31373.
    
      o Minor features (continuous integration):
        - Run Doxygen Makefile target on Travis, so we can learn about
          regressions in our internal documentation. Closes ticket 32455.
        - Stop allowing failures on the Travis CI stem tests job. It looks
          like all the stem hangs we were seeing before are now fixed.
          Closes ticket 33075.
    
      o Minor features (controller):
        - Add stream isolation data to STREAM event. Closes ticket 19859.
        - Implement a new GETINFO command to fetch microdescriptor
          consensus. Closes ticket 31684.
    
      o Minor features (debugging, directory system):
        - Don't crash when we find a non-guard with a guard-fraction value
          set. Instead, log a bug warning, in an attempt to figure out how
          this happened. Diagnostic for ticket 32868.
    
      o Minor features (defense in depth):
        - Add additional checks around tor_vasprintf() usage, in case the
          function returns an error. Patch by Tobias Stoeckmann. Fixes
          ticket 31147.
    
      o Minor features (developer tools):
        - Remove the 0.2.9.x series branches from git scripts (git-merge-
          forward.sh, git-pull-all.sh, git-push-all.sh, git-setup-dirs.sh).
          Closes ticket 32772.
        - Add a check_cocci_parse.sh script that checks that new code is
          parseable by Coccinelle. Add an exceptions file for unparseable
          files, and run the script from travis CI. Closes ticket 31919.
        - Call the check_cocci_parse.sh script from a 'check-cocci' Makefile
          target. Closes ticket 31919.
        - Add a rename_c_identifiers.py tool to rename a bunch of C
          identifiers at once, and generate a well-formed commit message
          describing the change. This should help with refactoring. Closes
          ticket 32237.
        - Add some scripts in "scripts/coccinelle" to invoke the Coccinelle
          semantic patching tool with the correct flags. These flags are
          fairly easy to forget, and these scripts should help us use
          Coccinelle more effectively in the future. Closes ticket 31705.
    
      o Minor features (diagnostic):
        - Improve assertions and add some memory-poisoning code to try to
          track down possible causes of a rare crash (32564) in the EWMA
          code. Closes ticket 33290.
    
      o Minor features (directory authorities):
        - Directory authorities now reject descriptors from relays running
          Tor versions from the 0.2.9 and 0.4.0 series. The 0.3.5 series is
          still allowed. Resolves ticket 32672. Patch by Neel Chauhan.
    
      o Minor features (Doxygen):
        - Update Doxygen configuration file to a more recent template (from
          1.8.15). Closes ticket 32110.
        - "make doxygen" now works with out-of-tree builds. Closes
          ticket 32113.
        - Make sure that doxygen outputs documentation for all of our C
          files. Previously, some were missing @file declarations, causing
          them to be ignored. Closes ticket 32307.
        - Our "make doxygen" target now respects --enable-fatal-warnings by
          default, and does not warn about items that are missing
          documentation. To warn about missing documentation, run configure
          with the "--enable-missing-doc-warnings" flag: doing so suspends
          fatal warnings for doxygen. Closes ticket 32385.
    
      o Minor features (git scripts):
        - Add TOR_EXTRA_CLONE_ARGS to git-setup-dirs.sh for git clone
          customisation. Closes ticket 32347.
        - Add git-setup-dirs.sh, which sets up an upstream git repository
          and worktrees for tor maintainers. Closes ticket 29603.
        - Add TOR_EXTRA_REMOTE_* to git-setup-dirs.sh for a custom extra
          remote. Closes ticket 32347.
        - Call the check_cocci_parse.sh script from the git commit and push
          hooks. Closes ticket 31919.
        - Make git-push-all.sh skip unchanged branches when pushing to
          upstream. The script already skipped unchanged test branches.
          Closes ticket 32216.
        - Make git-setup-dirs.sh create a master symlink in the worktree
          directory. Closes ticket 32347.
        - Skip unmodified source files when doing some existing git hook
          checks. Related to ticket 31919.
    
      o Minor features (IPv6, client):
        - Make Tor clients tell dual-stack exits that they prefer IPv6
          connections. This change is equivalent to setting the PreferIPv6
          flag on SOCKSPorts (and most other listener ports). Tor Browser
          has been setting this flag for some time, and we want to remove a
          client distinguisher at exits. Closes ticket 32637.
    
      o Minor features (portability, android):
        - When building for Android, disable some tests that depend on $HOME
          and/or pwdb, which Android doesn't have. Closes ticket 32825.
          Patch from Hans-Christoph Steiner.
    
      o Minor features (relay modularity):
        - Split the relay and server pluggable transport config code into
          separate files in the relay module. Disable this code when the
          relay module is disabled. Closes part of ticket 32213.
        - When the relay module is disabled, reject attempts to set the
          ORPort, DirPort, DirCache, BridgeRelay, ExtORPort, or
          ServerTransport* options, rather than ignoring the values of these
          options. Closes part of ticket 32213.
        - When the relay module is disabled, change the default config so
          that DirCache is 0, and ClientOnly is 1. Closes ticket 32410.
    
      o Minor features (release tools):
        - Port our ChangeLog formatting and sorting tools to Python 3.
          Closes ticket 32704.
    
      o Minor features (testing):
        - The unit tests now support a "TOR_SKIP_TESTCASES" environment
          variable to specify a list of space-separated test cases that
          should not be executed. We will use this to disable certain tests
          that are failing on Appveyor because of mismatched OpenSSL
          libraries. Part of ticket 33643.
        - Detect some common failure cases for test_parseconf.sh in
          src/test/conf_failures. Closes ticket 32451.
        - Allow test_parseconf.sh to test expected log outputs for successful
          configs, as well as failed configs. Closes ticket 32451.
        - The test_parseconf.sh script now supports result variants for any
          combination of the optional libraries lzma, nss, and zstd. Closes
          ticket 32397.
        - When running the unit tests on Android, create temporary files in
          a subdirectory of /data/local/tmp. Closes ticket 32172. Based on a
          patch from Hans-Christoph Steiner.
    
      o Minor features (usability):
        - Include more information when failing to parse a configuration
          value. This should make it easier to tell what's going wrong when
          a configuration file doesn't parse. Closes ticket 33460.
    
      o Minor bugfix (relay, configuration):
        - Warn if the ContactInfo field is not set, and tell the relay
          operator that not having a ContactInfo field set might cause their
          relay to get rejected in the future. Fixes bug 33361; bugfix
          on 0.1.1.10-alpha.
    
      o Minor bugfixes (bridges):
        - Lowercase the configured value of BridgeDistribution before adding
          it to the descriptor. Fixes bug 32753; bugfix on 0.3.2.3-alpha.
    
      o Minor bugfixes (build system):
        - Fix "make autostyle" for out-of-tree builds. Fixes bug 32370;
          bugfix on 0.4.1.2-alpha.
    
      o Minor bugfixes (compiler compatibility):
        - Avoid compiler warnings from Clang 10 related to the use of GCC-
          style "/* falls through */" comments. Both Clang and GCC allow
          __attribute__((fallthrough)) instead, so that's what we're using
          now. Fixes bug 34078; bugfix on 0.3.1.3-alpha.
        - Fix compilation warnings with GCC 10.0.1. Fixes bug 34077; bugfix
          on 0.4.0.3-alpha.
    
      o Minor bugfixes (configuration handling):
        - Make control_event_conf_changed() take in a config_line_t instead
          of a smartlist of alternating key/value entries. Fixes bug 31531;
          bugfix on 0.2.3.3-alpha. Patch by Neel Chauhan.
        - Check for multiplication overflow when parsing memory units inside
          configuration. Fixes bug 30920; bugfix on 0.0.9rc1.
        - When dumping the configuration, stop adding a trailing space after
          the option name when there is no option value. This issue only
          affects options that accept an empty value or list. (Most options
          reject empty values, or delete the entire line from the dumped
          options.) Fixes bug 32352; bugfix on 0.0.9pre6.
        - Avoid changing the user's value of HardwareAccel as stored by
          SAVECONF, when AccelName is set but HardwareAccel is not. Fixes
          bug 32382; bugfix on 0.2.2.1-alpha.
        - When creating a KeyDirectory with the same location as the
          DataDirectory (not recommended), respect the DataDirectory's
          group-readable setting if one has not been set for the
          KeyDirectory. Fixes bug 27992; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (continuous integration):
        - Remove the buggy and unused mirroring job. Fixes bug 33213; bugfix
          on 0.3.2.2-alpha.
    
      o Minor bugfixes (controller protocol):
        - When receiving "ACTIVE" or "DORMANT" signals on the control port,
          report them as SIGNAL events. Previously we would log a bug
          warning. Fixes bug 33104; bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (controller):
        - In routerstatus_has_changed(), check all the fields that are
          output over the control port. Fixes bug 20218; bugfix
          on 0.1.1.11-alpha.
    
      o Minor bugfixes (developer tools):
        - Allow paths starting with ./ in scripts/add_c_file.py. Fixes bug
          31336; bugfix on 0.4.1.2-alpha.
    
      o Minor bugfixes (dirauth module):
        - Split the dirauth config code into a separate file in the dirauth
          module. Disable this code when the dirauth module is disabled.
          Closes ticket 32213.
        - When the dirauth module is disabled, reject attempts to set the
          AuthoritativeDir option, rather than ignoring the value of the
          option. Fixes bug 32213; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (embedded Tor):
        - When starting Tor any time after the first time in a process,
          register the thread in which it is running as the main thread.
          Previously, we only did this on Windows, which could lead to bugs
          like 23081 on non-Windows platforms. Fixes bug 32884; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (git scripts):
        - Avoid sleeping before the last push in git-push-all.sh. Closes
          ticket 32216.
        - Forward all unrecognised arguments in git-push-all.sh to git push.
          Closes ticket 32216.
    
      o Minor bugfixes (key portability):
        - When reading PEM-encoded key data, tolerate CRLF line-endings even
          if we are not running on Windows. Previously, non-Windows hosts
          would reject these line-endings in certain positions, making
          certain key files hard to move from one host to another. Fixes bug
          33032; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (logging):
        - Stop truncating IPv6 addresses and ports in channel and connection
          logs. Fixes bug 33918; bugfix on 0.2.4.4-alpha.
        - Flush stderr, stdout, and file logs during shutdown, if supported
          by the OS. This change helps make sure that any final logs are
          recorded. Fixes bug 33087; bugfix on 0.4.1.6.
        - Stop closing stderr and stdout during shutdown. Closing these file
          descriptors can hide sanitiser logs. Fixes bug 33087; bugfix
          on 0.4.1.6.
        - If we encounter a bug when flushing a buffer to a TLS connection,
          only log the bug once per invocation of the Tor process.
          Previously we would log with every occurrence, which could cause
          us to run out of disk space. Fixes bug 33093; bugfix
          on 0.3.2.2-alpha.
        - When logging a bug, do not say "Future instances of this warning
          will be silenced" unless we are actually going to silence them.
          Previously we would say this whenever a BUG() check failed in the
          code. Fixes bug 33095; bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (onion services v2):
        - Move a series of v2 onion service warnings to protocol-warning
          level because they can all be triggered remotely by a malformed
          request. Fixes bug 32706; bugfix on 0.1.1.14-alpha.
        - When sending the INTRO cell for a v2 Onion Service, look at the
          failure cache alongside timeout values to check if the intro point
          is marked as failed. Previously, we only looked at the relay
          timeout values. Fixes bug 25568; bugfix on 0.2.7.3-rc. Patch by
          Neel Chauhan.
    
      o Minor bugfixes (onion services v3):
        - Remove a BUG() warning that would cause a stack trace if an onion
          service descriptor was freed while we were waiting for a
          rendezvous circuit to complete. Fixes bug 28992; bugfix
          on 0.3.2.1-alpha.
        - Relax severity of a log message that can appear naturally when
          decoding onion service descriptors as a relay. Also add some
          diagnostics to debug any future bugs in that area. Fixes bug
          31669; bugfix on 0.3.0.1-alpha.
        - Fix an assertion failure that could result from a corrupted
          ADD_ONION control port command. Found by Saibato. Fixes bug 33137;
          bugfix on 0.3.3.1-alpha. This issue is also tracked
          as TROVE-2020-003.
        - Properly handle the client rendezvous circuit timeout. Previously
          Tor would sometimes timeout a rendezvous circuit awaiting the
          introduction ACK, and find itself unable to re-establish all
          circuits because the rendezvous circuit timed out too early. Fixes
          bug 32021; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion services):
        - Do not rely on a "circuit established" flag for intro circuits but
          instead always query the HS circuit map. This is to avoid sync
          issue with that flag and the map. Fixes bug 32094; bugfix
          on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion services, all):
        - In cancel_descriptor_fetches(), use
          connection_list_by_type_purpose() instead of
          connection_list_by_type_state(). Fixes bug 32639; bugfix on
          0.3.2.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (pluggable transports):
        - When receiving a message on standard error from a pluggable
          transport, log it at info level, rather than as a warning. Fixes
          bug 33005; bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (rust, build):
        - Fix a syntax warning given by newer versions of Rust that was
          creating problems for our continuous integration. Fixes bug 33212;
          bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (scripts):
        - Fix update_versions.py for out-of-tree builds. Fixes bug 32371;
          bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (testing):
        - Use the same code to find the tor binary in all of our test
          scripts. This change makes sure we are always using the coverage
          binary when coverage is enabled. Fixes bug 32368; bugfix
          on 0.2.7.3-rc.
        - Stop ignoring "tor --dump-config" errors in test_parseconf.sh.
          Fixes bug 32468; bugfix on 0.4.2.1-alpha.
        - Our option-validation tests no longer depend on specially
          configured non-default, non-passing sets of options. Previously,
          the tests had been written to assume that options would _not_ be
          set to their defaults, which led to needless complexity and
          verbosity. Fixes bug 32175; bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (TLS bug handling):
        - When encountering a bug in buf_read_from_tls(), return a "MISC"
          error code rather than "WANTWRITE". This change might help avoid
          some CPU-wasting loops if the bug is ever triggered. Bug reported
          by opara. Fixes bug 32673; bugfix on 0.3.0.4-alpha.
    
      o Deprecated features:
        - Deprecate the ClientAutoIPv6ORPort option. This option was not
          true "Happy Eyeballs", and often failed on connections that
          weren't reliably dual-stack. Closes ticket 32942. Patch by
          Neel Chauhan.
    
      o Documentation:
        - Provide a quickstart guide for a Circuit Padding Framework, and
          documentation for researchers to implement and study circuit
          padding machines. Closes ticket 28804.
        - Add documentation in 'HelpfulTools.md' to describe how to build a
          tag file. Closes ticket 32779.
        - Create a high-level description of the long-term software
          architecture goals. Closes ticket 32206.
        - Describe the --dump-config command in the manual page. Closes
          ticket 32467.
        - Unite coding advice from this_not_that.md in torguts repo into our
          coding standards document. Resolves ticket 31853.
    
      o Removed features:
        - Our Doxygen configuration no longer generates LaTeX output. The
          reference manual produced by doing this was over 4000 pages long,
          and generally unusable. Closes ticket 32099.
        - The option "TestingEstimatedDescriptorPropagationTime" is now
          marked as obsolete. It has had no effect since 0.3.0.7, when
          clients stopped rejecting consensuses "from the future". Closes
          ticket 32807.
        - We no longer support consensus methods before method 28; these
          methods were only used by authorities running versions of Tor that
          are now at end-of-life. In effect, this means that clients,
          relays, and authorities now assume that authorities will be
          running version 0.3.5.x or later. Closes ticket 32695.
    
      o Testing:
        - Avoid conflicts between the fake sockets in tor's unit tests, and
          real file descriptors. Resolves issues running unit tests with
          GitHub Actions, where the process that embeds or launches the
          tests has already opened a large number of file descriptors. Fixes
          bug 33782; bugfix on 0.2.8.1-alpha. Found and fixed by
          Putta Khunchalee.
        - Add more test cases for tor's UTF-8 validation function. Also,
          check the arguments passed to the function for consistency. Closes
          ticket 32845.
        - Improve test coverage for relay and dirauth config code, focusing
          on option validation and normalization. Closes ticket 32213.
        - Improve the consistency of test_parseconf.sh output, and run all
          the tests, even if one fails. Closes ticket 32213.
        - Run the practracker unit tests in the pre-commit git hook. Closes
          ticket 32609.
    
      o Code simplification and refactoring (channel):
        - Channel layer had a variable length cell handler that was not used
          and thus removed. Closes ticket 32892.
    
      o Code simplification and refactoring (configuration):
        - Immutability is now implemented as a flag on individual
          configuration options rather than as part of the option-transition
          checking code. Closes ticket 32344.
        - Instead of keeping a list of configuration options to check for
          relative paths, check all the options whose type is "FILENAME".
          Solves part of ticket 32339.
        - Our default log (which ordinarily sends NOTICE-level messages to
          standard output) is now handled in a more logical manner.
          Previously, we replaced the configured log options if they were
          empty. Now, we interpret an empty set of log options as meaning
          "use the default log". Closes ticket 31999.
        - Remove some unused arguments from the options_validate() function,
          to simplify our code and tests. Closes ticket 32187.
        - Simplify the options_validate() code so that it looks at the
          default options directly, rather than taking default options as an
          argument. This change lets us simplify its interface. Closes
          ticket 32185.
        - Use our new configuration architecture to move most authority-
          related options to the directory authority module. Closes
          ticket 32806.
        - When parsing the command line, handle options that determine our
          "quiet level" and our mode of operation (e.g., --dump-config and
          so on) all in one table. Closes ticket 32003.
    
      o Code simplification and refactoring (controller):
        - Create a new abstraction for formatting control protocol reply
          lines based on key-value pairs. Refactor some existing control
          protocol code to take advantage of this. Closes ticket 30984.
        - Create a helper function that can fetch network status or
          microdesc consensuses. Closes ticket 31684.
    
      o Code simplification and refactoring (dirauth modularization):
        - Remove the last remaining HAVE_MODULE_DIRAUTH inside a function.
          Closes ticket 32163.
        - Replace some confusing identifiers in process_descs.c. Closes
          ticket 29826.
        - Simplify some relay and dirauth config code. Closes ticket 32213.
    
      o Code simplification and refactoring (mainloop):
        - Simplify the ip_address_changed() function by removing redundant
          checks. Closes ticket 33091.
    
      o Code simplification and refactoring (misc):
        - Make all the structs we declare follow the same naming convention
          of ending with "_t". Closes ticket 32415.
        - Move and rename some configuration-related code for clarity.
          Closes ticket 32304.
        - Our include.am files are now broken up by subdirectory.
          Previously, src/core/include.am covered all of the subdirectories
          in "core", "feature", and "app". Closes ticket 32137.
        - Remove underused NS*() macros from test code: they make our tests
          more confusing, especially for code-formatting tools. Closes
          ticket 32887.
    
      o Code simplification and refactoring (relay modularization):
        - Disable relay_periodic when the relay module is disabled. Closes
          ticket 32244.
        - Disable relay_sys when the relay module is disabled. Closes
          ticket 32245.
    
      o Code simplification and refactoring (tool support):
        - Add numerous missing dependencies to our include files, so that
          they can be included in different reasonable orders and still
          compile. Addresses part of ticket 32764.
        - Fix some parts of our code that were difficult for Coccinelle to
          parse. Related to ticket 31705.
        - Fix some small issues in our code that prevented automatic
          formatting tools from working. Addresses part of ticket 32764.
    
      o Documentation (manpage):
        - Alphabetize the Server and Directory server sections of the tor
          manpage. Also split Statistics options into their own section of
          the manpage. Closes ticket 33188. Work by Swati Thacker as part of
          Google Season of Docs.
        - Document the __OwningControllerProcess torrc option and specify
          its polling interval. Resolves issue 32971.
        - Split "Circuit Timeout" options and "Node Selection" options into
          their own sections of the tor manpage. Closes tickets 32928 and
          32929. Work by Swati Thacker as part of Google Season of Docs.
        - Alphabetize the Client Options section of the tor manpage. Closes
          ticket 32846.
        - Alphabetize the General Options section of the tor manpage. Closes
          ticket 32708.
        - In the tor(1) manpage, reword and improve formatting of the
          COMMAND-LINE OPTIONS and DESCRIPTION sections. Closes ticket
          32277. Based on work by Swati Thacker as part of Google Season
          of Docs.
        - In the tor(1) manpage, reword and improve formatting of the FILES,
          SEE ALSO, and BUGS sections. Closes ticket 32176. Based on work by
          Swati Thacker as part of Google Season of Docs.
    
      o Testing (Appveyor CI):
        - In our Appveyor Windows CI, copy required DLLs to test and app
          directories, before running tor's tests. This ensures that tor.exe
          and test*.exe use the correct version of each DLL. This fix is not
          required, but we hope it will avoid DLL search issues in future.
          Fixes bug 33673; bugfix on 0.3.4.2-alpha.
        - On Appveyor, skip the crypto/openssl_version test, which is
          failing because of a mismatched library installation. Fix
          for 33643.
    
      o Testing (circuit, EWMA):
        - Add unit tests for circuitmux and EWMA subsystems. Closes
          ticket 32196.
    
      o Testing (Travis CI):
        - Remove a redundant distcheck job. Closes ticket 33194.
        - Sort the Travis jobs in order of speed: putting the slowest jobs
          first takes full advantage of Travis job concurrency. Closes
          ticket 33194.
        - Stop allowing the Chutney IPv6 Travis job to fail. This job was
          previously configured to fast_finish (which requires
          allow_failure), to speed up the build. Closes ticket 33195.
        - When a Travis chutney job fails, use chutney's new "diagnostics.sh"
          tool to produce detailed diagnostic output. Closes ticket 32792.
    
    
    Changes in version 0.4.2.7 - 2020-03-18
      This is the third stable release in the 0.4.2.x series. It backports
      numerous fixes from later releases, including a fix for TROVE-2020-
      002, a major denial-of-service vulnerability that affected all
      released Tor instances since 0.2.1.5-alpha. Using this vulnerability,
      an attacker could cause Tor instances to consume a huge amount of CPU,
      disrupting their operations for several seconds or minutes. This
      attack could be launched by anybody against a relay, or by a directory
      cache against any client that had connected to it. The attacker could
      launch this attack as much as they wanted, thereby disrupting service
      or creating patterns that could aid in traffic analysis. This issue
      was found by OSS-Fuzz, and is also tracked as CVE-2020-10592.
    
      We do not have reason to believe that this attack is currently being
      exploited in the wild, but nonetheless we advise everyone to upgrade
      as soon as packages are available.
    
      o Major bugfixes (security, denial-of-service, backport from 0.4.3.3-alpha):
        - Fix a denial-of-service bug that could be used by anyone to
          consume a bunch of CPU on any Tor relay or authority, or by
          directories to consume a bunch of CPU on clients or hidden
          services. Because of the potential for CPU consumption to
          introduce observable timing patterns, we are treating this as a
          high-severity security issue. Fixes bug 33119; bugfix on
          0.2.1.5-alpha. Found by OSS-Fuzz. We are also tracking this issue
          as TROVE-2020-002 and CVE-2020-10592.
    
      o Major bugfixes (circuit padding, memory leak, backport from 0.4.3.3-alpha):
        - Avoid a remotely triggered memory leak in the case that a circuit
          padding machine is somehow negotiated twice on the same circuit.
          Fixes bug 33619; bugfix on 0.4.0.1-alpha. Found by Tobias Pulls.
          This is also tracked as TROVE-2020-004 and CVE-2020-10593.
    
      o Major bugfixes (directory authority, backport from 0.4.3.3-alpha):
        - Directory authorities will now send a 503 (not enough bandwidth)
          code to clients when under bandwidth pressure. Known relays and
          other authorities will always be answered regardless of the
          bandwidth situation. Fixes bug 33029; bugfix on 0.1.2.5-alpha.
    
      o Minor features (continuous integration, backport from 0.4.3.2-alpha):
        - Stop allowing failures on the Travis CI stem tests job. It looks
          like all the stem hangs we were seeing before are now fixed.
          Closes ticket 33075.
    
      o Minor bugfixes (bridges, backport from 0.4.3.1-alpha):
        - Lowercase the configured value of BridgeDistribution before adding
          it to the descriptor. Fixes bug 32753; bugfix on 0.3.2.3-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.3.2-alpha):
        - If we encounter a bug when flushing a buffer to a TLS connection,
          only log the bug once per invocation of the Tor process.
          Previously we would log with every occurrence, which could cause
          us to run out of disk space. Fixes bug 33093; bugfix
          on 0.3.2.2-alpha.
    
      o Minor bugfixes (onion services v3, backport from 0.4.3.3-alpha):
        - Fix an assertion failure that could result from a corrupted
          ADD_ONION control port command. Found by Saibato. Fixes bug 33137;
          bugfix on 0.3.3.1-alpha. This issue is also tracked
          as TROVE-2020-003.
    
      o Minor bugfixes (rust, build, backport from 0.4.3.2-alpha):
        - Fix a syntax warning given by newer versions of Rust that was
          creating problems for our continuous integration. Fixes bug 33212;
          bugfix on 0.3.5.1-alpha.
    
      o Testing (Travis CI, backport from 0.4.3.3-alpha):
        - Remove a redundant distcheck job. Closes ticket 33194.
        - Sort the Travis jobs in order of speed: putting the slowest jobs
          first takes full advantage of Travis job concurrency. Closes
          ticket 33194.
        - Stop allowing the Chutney IPv6 Travis job to fail. This job was
          previously configured to fast_finish (which requires
          allow_failure), to speed up the build. Closes ticket 33195.
        - When a Travis chutney job fails, use chutney's new "diagnostics.sh"
          tool to produce detailed diagnostic output. Closes ticket 32792.
    
    
    Changes in version 0.4.1.9 - 2020-03-18
      Tor 0.4.1.9 backports important fixes from later Tor releases,
      including a fix for TROVE-2020-002, a major denial-of-service
      vulnerability that affected all released Tor instances since
      0.2.1.5-alpha. Using this vulnerability, an attacker could cause Tor
      instances to consume a huge amount of CPU, disrupting their operations
      for several seconds or minutes. This attack could be launched by
      anybody against a relay, or by a directory cache against any client
      that had connected to it. The attacker could launch this attack as
      much as they wanted, thereby disrupting service or creating patterns
      that could aid in traffic analysis. This issue was found by OSS-Fuzz,
      and is also tracked as CVE-2020-10592.
    
      We do not have reason to believe that this attack is currently being
      exploited in the wild, but nonetheless we advise everyone to upgrade
      as soon as packages are available.
    
      o Major bugfixes (security, denial-of-service, backport from 0.4.3.3-alpha):
        - Fix a denial-of-service bug that could be used by anyone to
          consume a bunch of CPU on any Tor relay or authority, or by
          directories to consume a bunch of CPU on clients or hidden
          services. Because of the potential for CPU consumption to
          introduce observable timing patterns, we are treating this as a
          high-severity security issue. Fixes bug 33119; bugfix on
          0.2.1.5-alpha. Found by OSS-Fuzz. We are also tracking this issue
          as TROVE-2020-002 and CVE-2020-10592.
    
      o Major bugfixes (circuit padding, memory leak, backport from 0.4.3.3-alpha):
        - Avoid a remotely triggered memory leak in the case that a circuit
          padding machine is somehow negotiated twice on the same circuit.
          Fixes bug 33619; bugfix on 0.4.0.1-alpha. Found by Tobias Pulls.
          This is also tracked as TROVE-2020-004 and CVE-2020-10593.
    
      o Minor bugfixes (bridges, backport from 0.4.3.1-alpha):
        - Lowercase the configured value of BridgeDistribution before adding
          it to the descriptor. Fixes bug 32753; bugfix on 0.3.2.3-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.3.2-alpha):
        - If we encounter a bug when flushing a buffer to a TLS connection,
          only log the bug once per invocation of the Tor process.
          Previously we would log with every occurrence, which could cause
          us to run out of disk space. Fixes bug 33093; bugfix
          on 0.3.2.2-alpha.
    
      o Minor bugfixes (onion services v3, backport from 0.4.3.3-alpha):
        - Fix an assertion failure that could result from a corrupted
          ADD_ONION control port command. Found by Saibato. Fixes bug 33137;
          bugfix on 0.3.3.1-alpha. This issue is also tracked
          as TROVE-2020-003.
    
      o Minor bugfixes (rust, build, backport from 0.4.3.2-alpha):
        - Fix a syntax warning given by newer versions of Rust that was
          creating problems for our continuous integration. Fixes bug 33212;
          bugfix on 0.3.5.1-alpha.
    
      o Testing (Travis CI, backport from 0.4.3.3-alpha):
        - Remove a redundant distcheck job. Closes ticket 33194.
        - Sort the Travis jobs in order of speed: putting the slowest jobs
          first takes full advantage of Travis job concurrency. Closes
          ticket 33194.
        - Stop allowing the Chutney IPv6 Travis job to fail. This job was
          previously configured to fast_finish (which requires
          allow_failure), to speed up the build. Closes ticket 33195.
        - When a Travis chutney job fails, use chutney's new "diagnostics.sh"
          tool to produce detailed diagnostic output. Closes ticket 32792.
    
    
    Changes in version 0.3.5.10 - 2020-03-18
      Tor 0.3.5.10 backports many fixes from later Tor releases, including a
      fix for TROVE-2020-002, a major denial-of-service vulnerability that
      affected all released Tor instances since 0.2.1.5-alpha. Using this
      vulnerability, an attacker could cause Tor instances to consume a huge
      amount of CPU, disrupting their operations for several seconds or
      minutes. This attack could be launched by anybody against a relay, or
      by a directory cache against any client that had connected to it. The
      attacker could launch this attack as much as they wanted, thereby
      disrupting service or creating patterns that could aid in traffic
      analysis. This issue was found by OSS-Fuzz, and is also tracked
      as CVE-2020-10592.
    
      We do not have reason to believe that this attack is currently being
      exploited in the wild, but nonetheless we advise everyone to upgrade
      as soon as packages are available.
    
      o Major bugfixes (security, denial-of-service, backport from 0.4.3.3-alpha):
        - Fix a denial-of-service bug that could be used by anyone to
          consume a bunch of CPU on any Tor relay or authority, or by
          directories to consume a bunch of CPU on clients or hidden
          services. Because of the potential for CPU consumption to
          introduce observable timing patterns, we are treating this as a
          high-severity security issue. Fixes bug 33119; bugfix on
          0.2.1.5-alpha. Found by OSS-Fuzz. We are also tracking this issue
          as TROVE-2020-002 and CVE-2020-10592.
    
      o Major bugfixes (linux seccomp sandbox, backport from 0.4.3.1-alpha):
        - Correct how we use libseccomp. Particularly, stop assuming that
          rules are applied in a particular order or that more rules are
          processed after the first match. Neither is the case! In
          libseccomp <2.4.0 this lead to some rules having no effect.
          libseccomp 2.4.0 changed how rules are generated, leading to a
          different ordering, which in turn led to a fatal crash during
          startup. Fixes bug 29819; bugfix on 0.2.5.1-alpha. Patch by
          Peter Gerber.
    
      o Minor features (continuous integration, backport from 0.4.3.2-alpha):
        - Stop allowing failures on the Travis CI stem tests job. It looks
          like all the stem hangs we were seeing before are now fixed.
          Closes ticket 33075.
    
      o Minor bugfixes (bridges, backport from 0.4.3.1-alpha):
        - Lowercase the configured value of BridgeDistribution before adding
          it to the descriptor. Fixes bug 32753; bugfix on 0.3.2.3-alpha.
    
      o Minor bugfixes (crash, backport from 0.4.2.4-rc):
        - When running Tor with an option like --verify-config or
          --dump-config that does not start the event loop, avoid crashing
          if we try to exit early because of an error. Fixes bug 32407;
          bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.3.2-alpha):
        - If we encounter a bug when flushing a buffer to a TLS connection,
          only log the bug once per invocation of the Tor process.
          Previously we would log with every occurrence, which could cause
          us to run out of disk space. Fixes bug 33093; bugfix
          on 0.3.2.2-alpha.
    
      o Minor bugfixes (onion services v3, backport from 0.4.3.3-alpha):
        - Fix an assertion failure that could result from a corrupted
          ADD_ONION control port command. Found by Saibato. Fixes bug 33137;
          bugfix on 0.3.3.1-alpha. This issue is also tracked
          as TROVE-2020-003.
    
      o Minor bugfixes (rust, build, backport from 0.4.3.2-alpha):
        - Fix a syntax warning given by newer versions of Rust that was
          creating problems for our continuous integration. Fixes bug 33212;
          bugfix on 0.3.5.1-alpha.
    
      o Testing (backport from 0.4.3.1-alpha):
        - Re-enable the Travis CI macOS Chutney build, but don't let it
          prevent the Travis job from finishing. (The Travis macOS jobs are
          slow, so we don't want to have it delay the whole CI process.)
          Closes ticket 32629.
        - Turn off Tor's Sandbox in Chutney jobs, and run those jobs on
          Ubuntu Bionic. Turning off the Sandbox is a work-around, until we
          fix the sandbox errors in 32722. Closes ticket 32240.
    
      o Testing (continuous integration, backport from 0.4.3.1-alpha):
        - Use zstd in our Travis Linux builds. Closes ticket 32242.
    
      o Testing (Travis CI, backport from 0.4.3.3-alpha):
        - Remove a redundant distcheck job. Closes ticket 33194.
        - Sort the Travis jobs in order of speed: putting the slowest jobs
          first takes full advantage of Travis job concurrency. Closes
          ticket 33194.
        - Stop allowing the Chutney IPv6 Travis job to fail. This job was
          previously configured to fast_finish (which requires
        - When a Travis chutney job fails, use chutney's new "diagnostics.sh"
          tool to produce detailed diagnostic output. Closes ticket 32792.
    
    
    Changes in version 0.4.2.6 - 2020-01-30
      This is the second stable release in the 0.4.2.x series. It backports
      several bugfixes from 0.4.3.1-alpha, including some that had affected
      the Linux seccomp2 sandbox or Windows services. If you're running with
      one of those configurations, you'll probably want to upgrade;
      otherwise, you should be fine with 0.4.2.5.
    
      o Major bugfixes (linux seccomp sandbox, backport from 0.4.3.1-alpha):
        - Correct how we use libseccomp. Particularly, stop assuming that
          rules are applied in a particular order or that more rules are
          processed after the first match. Neither is the case! In
          libseccomp <2.4.0 this led to some rules having no effect.
          libseccomp 2.4.0 changed how rules are generated, leading to a
          different ordering, which in turn led to a fatal crash during
          startup. Fixes bug 29819; bugfix on 0.2.5.1-alpha. Patch by
          Peter Gerber.
        - Fix crash when reloading logging configuration while the
          experimental sandbox is enabled. Fixes bug 32841; bugfix on
          0.4.1.7. Patch by Peter Gerber.
    
      o Minor bugfixes (correctness checks, backport from 0.4.3.1-alpha):
        - Use GCC/Clang's printf-checking feature to make sure that
          tor_assertf() arguments are correctly typed. Fixes bug 32765;
          bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (logging, crash, backport from 0.4.3.1-alpha):
        - Avoid a possible crash when trying to log a (fatal) assertion
          failure about mismatched magic numbers in configuration objects.
          Fixes bug 32771; bugfix on 0.4.2.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.4.3.1-alpha):
        - When TOR_DISABLE_PRACTRACKER is set, do not apply it to the
          test_practracker.sh script. Doing so caused a test failure. Fixes
          bug 32705; bugfix on 0.4.2.1-alpha.
        - When TOR_DISABLE_PRACTRACKER is set, log a notice to stderr when
          skipping practracker checks. Fixes bug 32705; bugfix
          on 0.4.2.1-alpha.
    
      o Minor bugfixes (windows service, backport from 0.4.3.1-alpha):
        - Initialize the publish/subscribe system when running as a windows
          service. Fixes bug 32778; bugfix on 0.4.1.1-alpha.
    
      o Testing (backport from 0.4.3.1-alpha):
        - Turn off Tor's Sandbox in Chutney jobs, and run those jobs on
          Ubuntu Bionic. Turning off the Sandbox is a work-around, until we
          fix the sandbox errors in 32722. Closes ticket 32240.
        - Re-enable the Travis CI macOS Chutney build, but don't let it
          prevent the Travis job from finishing. (The Travis macOS jobs are
          slow, so we don't want to have it delay the whole CI process.)
          Closes ticket 32629.
    
      o Testing (continuous integration, backport from 0.4.3.1-alpha):
        - Use zstd in our Travis Linux builds. Closes ticket 32242.
    
    
    Changes in version 0.4.1.8 - 2020-01-30
      This release backports several bugfixes from later release series,
      including some that had affected the Linux seccomp2 sandbox or Windows
      services. If you're running with one of those configurations, you'll
      probably want to upgrade; otherwise, you should be fine with your
      current version of 0.4.1.x.
    
      o Major bugfixes (linux seccomp sandbox, backport from 0.4.3.1-alpha):
        - Correct how we use libseccomp. Particularly, stop assuming that
          rules are applied in a particular order or that more rules are
          processed after the first match. Neither is the case! In
          libseccomp <2.4.0 this led to some rules having no effect.
          libseccomp 2.4.0 changed how rules are generated, leading to a
          different ordering, which in turn led to a fatal crash during
          startup. Fixes bug 29819; bugfix on 0.2.5.1-alpha. Patch by
          Peter Gerber.
        - Fix crash when reloading logging configuration while the
          experimental sandbox is enabled. Fixes bug 32841; bugfix on
          0.4.1.7. Patch by Peter Gerber.
    
      o Minor bugfixes (crash, backport form 0.4.2.4-rc):
        - When running Tor with an option like --verify-config or
          --dump-config that does not start the event loop, avoid crashing
          if we try to exit early because of an error. Fixes bug 32407;
          bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (windows service, backport from 0.4.3.1-alpha):
        - Initialize the publish/subscribe system when running as a windows
          service. Fixes bug 32778; bugfix on 0.4.1.1-alpha.
    
      o Testing (backport from 0.4.3.1-alpha):
        - Turn off Tor's Sandbox in Chutney jobs, and run those jobs on
          Ubuntu Bionic. Turning off the Sandbox is a work-around, until we
          fix the sandbox errors in 32722. Closes ticket 32240.
        - Re-enable the Travis CI macOS Chutney build, but don't let it
          prevent the Travis job from finishing. (The Travis macOS jobs are
          slow, so we don't want to have it delay the whole CI process.)
          Closes ticket 32629.
    
      o Testing (continuous integration, backport from 0.4.3.1-alpha):
        - Use zstd in our Travis Linux builds. Closes ticket 32242.
    
    
    Changes in version 0.4.2.5 - 2019-12-09
      This is the first stable release in the 0.4.2.x series. This series
      improves reliability and stability, and includes several stability and
      correctness improvements for onion services. It also fixes many smaller
      bugs present in previous series.
    
      Per our support policy, we will support the 0.4.2.x series for nine
      months, or until three months after the release of a stable 0.4.3.x:
      whichever is longer. If you need longer-term support, please stick
      with 0.3.5.x, which will we plan to support until Feb 2022.
    
      Below are the changes since 0.4.1.4-rc. For a complete list of only
      the changes since 0.4.2.4-rc, see the ChangeLog file.
    
      o Major features (directory authorities):
        - Directory authorities now reject relays running all currently
          deprecated release series. The currently supported release series
          are: 0.2.9, 0.3.5, 0.4.0, 0.4.1, and 0.4.2. Closes ticket 31549.
    
      o Major features (onion service v3, denial of service):
        - Add onion service introduction denial of service defenses. Intro
          points can now rate-limit client introduction requests, using
          parameters that can be sent by the service within the
          ESTABLISH_INTRO cell. If the cell extension for this is not used,
          the intro point will honor the consensus parameters. Closes
          ticket 30924.
    
      o Major bugfixes (circuit build, guard):
        - When considering upgrading circuits from "waiting for guard" to
          "open", always ignore circuits that are marked for close.
          Previously we could end up in the situation where a subsystem is
          notified of a circuit opening, but the circuit is still marked for
          close, leading to undesirable behavior. Fixes bug 30871; bugfix
          on 0.3.0.1-alpha.
    
      o Major bugfixes (crash, Linux, Android):
        - Tolerate systems (including some Android installations) where
          madvise and MADV_DONTDUMP are available at build-time, but not at
          run time. Previously, these systems would notice a failed syscall
          and abort. Fixes bug 31570; bugfix on 0.4.1.1-alpha.
        - Tolerate systems (including some Linux installations) where
          madvise and/or MADV_DONTFORK are available at build-time, but not
          at run time. Previously, these systems would notice a failed
          syscall and abort. Fixes bug 31696; bugfix on 0.4.1.1-alpha.
    
      o Major bugfixes (embedded Tor):
        - Avoid a possible crash when restarting Tor in embedded mode and
          enabling a different set of publish/subscribe messages. Fixes bug
          31898; bugfix on 0.4.1.1-alpha.
    
      o Major bugfixes (relay):
        - Relays now respect their AccountingMax bandwidth again. When
          relays entered "soft" hibernation (which typically starts when
          we've hit 90% of our AccountingMax), we had stopped checking
          whether we should enter hard hibernation. Soft hibernation refuses
          new connections and new circuits, but the existing circuits can
          continue, meaning that relays could have exceeded their configured
          AccountingMax. Fixes bug 32108; bugfix on 0.4.0.1-alpha.
    
      o Major bugfixes (torrc parsing):
        - Stop ignoring torrc options after an %include directive, when the
          included directory ends with a file that does not contain any
          config options (but does contain comments or whitespace). Fixes
          bug 31408; bugfix on 0.3.1.1-alpha.
    
      o Major bugfixes (v3 onion services):
        - Onion services now always use the exact number of intro points
          configured with the HiddenServiceNumIntroductionPoints option (or
          fewer if nodes are excluded). Before, a service could sometimes
          pick more intro points than configured. Fixes bug 31548; bugfix
          on 0.3.2.1-alpha.
    
      o Minor feature (onion services, control port):
        - The ADD_ONION command's keyword "BEST" now defaults to ED25519-V3
          (v3) onion services. Previously it defaulted to RSA1024 (v2).
          Closes ticket 29669.
    
      o Minor features (auto-formatting scripts):
        - When annotating C macros, never generate a line that our check-
          spaces script would reject. Closes ticket 31759.
        - When annotating C macros, try to remove cases of double-negation.
          Closes ticket 31779.
    
      o Minor features (best practices tracker):
        - Our best-practices tracker now integrates with our include-checker
          tool to keep track of how many layering violations we have not yet
          fixed. We hope to reduce this number over time to improve Tor's
          modularity. Closes ticket 31176.
        - Add a TOR_PRACTRACKER_OPTIONS variable for passing arguments to
          practracker from the environment. We may want this for continuous
          integration. Closes ticket 31309.
        - Give a warning rather than an error when a practracker exception
          is violated by a small amount, add a --list-overbroad option to
          practracker that lists exceptions that are stricter than they need
          to be, and provide an environment variable for disabling
          practracker. Closes ticket 30752.
        - Our best-practices tracker now looks at headers as well as C
          files. Closes ticket 31175.
    
      o Minor features (build system):
        - Make pkg-config use --prefix when cross-compiling, if
          PKG_CONFIG_PATH is not set. Closes ticket 32191.
        - Add --disable-manpage and --disable-html-manual options to
          configure script. This will enable shortening build times by not
          building documentation. Resolves issue 19381.
    
      o Minor features (compilation):
        - Log a more useful error message when we are compiling and one of
          the compile-time hardening options we have selected can be linked
          but not executed. Closes ticket 27530.
    
      o Minor features (configuration):
        - The configuration code has been extended to allow splitting
          configuration data across multiple objects. Previously, all
          configuration data needed to be kept in a single object, which
          tended to become bloated. Closes ticket 31240.
    
      o Minor features (continuous integration):
        - When building on Appveyor and Travis, pass the "-k" flag to make,
          so that we are informed of all compilation failures, not just the
          first one or two. Closes ticket 31372.
        - When running CI builds on Travis, put some random data in
          ~/.torrc, to make sure no tests are reading the Tor configuration
          file from its default location. Resolves issue 30102.
    
      o Minor features (debugging):
        - Log a nonfatal assertion failure if we encounter a configuration
          line whose command is "CLEAR" but which has a nonempty value. This
          should be impossible, according to the rules of our configuration
          line parsing. Closes ticket 31529.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the December 3 2019 Maxmind GeoLite2
          Country database. Closes ticket 32685.
    
      o Minor features (git hooks):
        - Our pre-commit git hook now checks for a special file before
          running practracker, so that practracker only runs on branches
          that are based on master. Since the pre-push hook calls the pre-
          commit hook, practracker will also only run before pushes of
          branches based on master. Closes ticket 30979.
    
      o Minor features (git scripts):
        - Add a "--" command-line argument, to separate git-push-all.sh
          script arguments from arguments that are passed through to git
          push. Closes ticket 31314.
        - Add a -r <remote-name> argument to git-push-all.sh, so the script
          can push test branches to a personal remote. Closes ticket 31314.
        - Add a -t <test-branch-prefix> argument to git-merge-forward.sh and
          git-push-all.sh, which makes these scripts create, merge forward,
          and push test branches. Closes ticket 31314.
        - Add a -u argument to git-merge-forward.sh, so that the script can
          re-use existing test branches after a merge failure and fix.
          Closes ticket 31314.
        - Add a TOR_GIT_PUSH env var, which sets the default git push
          command and arguments for git-push-all.sh. Closes ticket 31314.
        - Add a TOR_PUSH_DELAY variable to git-push-all.sh, which makes the
          script push master and maint branches with a delay between each
          branch. These delays trigger the CI jobs in a set order, which
          should show the most likely failures first. Also make pushes
          atomic by default, and make the script pass any command-line
          arguments to git push. Closes ticket 29879.
        - Call the shellcheck script from the pre-commit hook. Closes
          ticket 30967.
        - Skip pushing test branches that are the same as a remote
          maint/release/master branch in git-push-all.sh by default. Add a
          -s argument, so git-push-all.sh can push all test branches. Closes
          ticket 31314.
    
      o Minor features (IPv6, logging):
        - Log IPv6 addresses as well as IPv4 addresses when describing
          routerinfos, routerstatuses, and nodes. Closes ticket 21003.
    
      o Minor features (maintenance scripts):
        - Add a Coccinelle script to detect bugs caused by incrementing or
          decrementing a variable inside a call to log_debug(). Since
          log_debug() is a macro whose arguments are conditionally
          evaluated, it is usually an error to do this. One such bug was
          30628, in which SENDME cells were miscounted by a decrement
          operator inside a log_debug() call. Closes ticket 30743.
    
      o Minor features (onion service v3):
        - Do not allow single hop clients to fetch or post an HS descriptor
          from an HSDir. Closes ticket 24964.
    
      o Minor features (onion service):
        - Disallow single-hop clients at the introduction point. We've
          removed Tor2web support a while back and single-hop rendezvous
          attempts are blocked at the relays. This change should remove load
          off the network from spammy clients. Close ticket 24963.
    
      o Minor features (onion services v3):
        - Assist users who try to setup v2 client authorization in v3 onion
          services by pointing them to the right documentation. Closes
          ticket 28966.
    
      o Minor features (stem tests):
        - Change "make test-stem" so it only runs the stem tests that use
          tor. This change makes test-stem faster and more reliable. Closes
          ticket 31554.
    
      o Minor features (testing):
        - When running tests that attempt to look up hostnames, replace the
          libc name lookup functions with ones that do not actually touch
          the network. This way, the tests complete more quickly in the
          presence of a slow or missing DNS resolver. Closes ticket 31841.
        - Add a script to invoke "tor --dump-config" and "tor
          --verify-config" with various configuration options, and see
          whether tor's resulting configuration or error messages are what
          we expect. Use it for integration testing of our +Option and
          /Option flags. Closes ticket 31637.
        - Improve test coverage for our existing configuration parsing and
          management API. Closes ticket 30893.
        - Add integration tests to make sure that practracker gives the
          outputs we expect. Closes ticket 31477.
        - The practracker self-tests are now run as part of the Tor test
          suite. Closes ticket 31304.
    
      o Minor features (testing, continuous integration):
        - Disable all but one Travis CI macOS build, to mitigate slow
          scheduling of Travis macOS jobs. Closes ticket 32177.
        - Run the chutney IPv6 networks as part of Travis CI. Closes
          ticket 30860.
        - Simplify the Travis CI build matrix, and optimise for build time.
          Closes ticket 31859.
        - Use Windows Server 2019 instead of Windows Server 2016 in our
          Appveyor builds. Closes ticket 32086.
    
      o Minor features (token bucket):
        - Implement a generic token bucket that uses a single counter, for
          use in anti-DoS onion service work. Closes ticket 30687.
    
      o Minor bugfixes (Appveyor continuous integration):
        - Avoid spurious errors when Appveyor CI fails before the install
          step. Fixes bug 31884; bugfix on 0.3.4.2-alpha.
    
      o Minor bugfixes (best practices tracker):
        - Fix a few issues in the best-practices script, including tests,
          tab tolerance, error reporting, and directory-exclusion logic.
          Fixes bug 29746; bugfix on 0.4.1.1-alpha.
        - When running check-best-practices, only consider files in the src
          subdirectory. Previously we had recursively considered all
          subdirectories, which made us get confused by the temporary
          directories made by "make distcheck". Fixes bug 31578; bugfix
          on 0.4.1.1-alpha.
    
      o Minor bugfixes (build system):
        - Interpret "--disable-module-dirauth=no" correctly. Fixes bug
          32124; bugfix on 0.3.4.1-alpha.
        - Interpret "--with-tcmalloc=no" correctly. Fixes bug 32124; bugfix
          on 0.2.0.20-rc.
        - Stop failing when jemalloc is requested, but tcmalloc is not
          found. Fixes bug 32124; bugfix on 0.3.5.1-alpha.
        - When pkg-config is not installed, or a library that depends on
          pkg-config is not found, tell the user what to do to fix the
          problem. Fixes bug 31922; bugfix on 0.3.1.1-alpha.
        - Do not include the deprecated <sys/sysctl.h> on Linux or Windows
          systems. Fixes bug 31673; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (chutney, makefiles, documentation):
        - "make test-network-all" now shows the warnings from each test-
          network.sh run on the console, so developers see new warnings
          early. We've also improved the documentation for this feature, and
          renamed a Makefile variable so the code is self-documenting. Fixes
          bug 30455; bugfix on 0.3.0.4-rc.
    
      o Minor bugfixes (client, onion service v3):
        - Fix a BUG() assertion that occurs within a very small race window
          between when a client intro circuit opens and when its descriptor
          gets cleaned up from the cache. The circuit is now closed early,
          which will trigger a re-fetch of the descriptor and continue the
          connection. Fixes bug 28970; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (code quality):
        - Fix "make check-includes" so it runs correctly on out-of-tree
          builds. Fixes bug 31335; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (compilation):
        - Add more stub functions to fix compilation on Android with link-
          time optimization when --disable-module-dirauth is used.
          Previously, these compilation settings would make the compiler
          look for functions that didn't exist. Fixes bug 31552; bugfix
          on 0.4.1.1-alpha.
        - Suppress spurious float-conversion warnings from GCC when calling
          floating-point classifier functions on FreeBSD. Fixes part of bug
          31687; bugfix on 0.3.1.5-alpha.
    
      o Minor bugfixes (configuration):
        - Invalid floating-point values in the configuration file are now
          treated as errors in the configuration. Previously, they were
          ignored and treated as zero. Fixes bug 31475; bugfix on 0.0.1.
    
      o Minor bugfixes (connections):
        - Avoid trying to read data from closed connections, which can cause
          needless loops in Libevent and infinite loops in Shadow. Fixes bug
          30344; bugfix on 0.1.1.1-alpha.
    
      o Minor bugfixes (controller protocol):
        - Fix the MAPADDRESS controller command to accept one or more
          arguments. Previously, it required two or more arguments, and
          ignored the first. Fixes bug 31772; bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (coverity):
        - Add an assertion when parsing a BEGIN cell so that coverity can be
          sure that we are not about to dereference a NULL address. Fixes
          bug 31026; bugfix on 0.2.4.7-alpha. This is CID 1447296.
        - In our siphash implementation, when building for coverity, use
          memcpy in place of a switch statement, so that coverity can tell
          we are not accessing out-of-bounds memory. Fixes bug 31025; bugfix
          on 0.2.8.1-alpha. This is tracked as CID 1447293 and 1447295.
        - Fix several coverity warnings from our unit tests. Fixes bug
          31030; bugfix on 0.2.4.1-alpha, 0.3.2.1-alpha, and 0.4.0.1-alpha.
    
      o Minor bugfixes (crash):
        - When running Tor with an option like --verify-config or
          --dump-config that does not start the event loop, avoid crashing
          if we try to exit early because of an error. Fixes bug 32407;
          bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (developer tooling):
        - Only log git script changes in the post-merge script when the
          merge was to the master branch. Fixes bug 31040; bugfix
          on 0.4.1.1-alpha.
    
      o Minor bugfixes (directory authorities):
        - Return a distinct status when formatting annotations fails. Fixes
          bug 30780; bugfix on 0.2.0.8-alpha.
    
      o Minor bugfixes (error handling):
        - Always lock the backtrace buffer before it is used. Fixes bug
          31734; bugfix on 0.2.5.3-alpha.
        - On abort, try harder to flush the output buffers of log messages.
          On some platforms (macOS), log messages could be discarded when
          the process terminates. Fixes bug 31571; bugfix on 0.3.5.1-alpha.
        - Report the tor version whenever an assertion fails. Previously, we
          only reported the Tor version on some crashes, and some non-fatal
          assertions. Fixes bug 31571; bugfix on 0.3.5.1-alpha.
        - When tor aborts due to an error, close log file descriptors before
          aborting. Closing the logs makes some OSes flush log file buffers,
          rather than deleting buffered log lines. Fixes bug 31594; bugfix
          on 0.2.5.2-alpha.
    
      o Minor bugfixes (FreeBSD, PF-based proxy, IPv6):
        - When extracting an IPv6 address from a PF-based proxy, verify that
          we are actually configured to receive an IPv6 address, and log an
          internal error if not. Fixes part of bug 31687; bugfix
          on 0.2.3.4-alpha.
    
      o Minor bugfixes (git hooks):
        - Remove a duplicate call to practracker from the pre-push hook. The
          pre-push hook already calls the pre-commit hook, which calls
          practracker. Fixes bug 31462; bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (git scripts):
        - Stop hard-coding the bash path in the git scripts. Some OSes don't
          have bash in /usr/bin, others have an ancient bash at this path.
          Fixes bug 30840; bugfix on 0.4.0.1-alpha.
        - Stop hard-coding the tor master branch name and worktree path in
          the git scripts. Fixes bug 30841; bugfix on 0.4.0.1-alpha.
        - Allow git-push-all.sh to be run from any directory. Previously,
          the script only worked if run from an upstream worktree directory.
          Closes ticket 31678.
    
      o Minor bugfixes (guards):
        - When tor is missing descriptors for some primary entry guards,
          make the log message less alarming. It's normal for descriptors to
          expire, as long as tor fetches new ones soon after. Fixes bug
          31657; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (ipv6):
        - Check for private IPv6 addresses alongside their IPv4 equivalents
          when authorities check descriptors. Previously, we only checked
          for private IPv4 addresses. Fixes bug 31088; bugfix on
          0.2.3.21-rc. Patch by Neel Chauhan.
        - When parsing microdescriptors, we should check the IPv6 exit
          policy alongside IPv4. Previously, we checked both exit policies
          for only router info structures, while microdescriptors were
          IPv4-only. Fixes bug 27284; bugfix on 0.2.3.1-alpha. Patch by
          Neel Chauhan.
    
      o Minor bugfixes (logging):
        - Add a missing check for HAVE_PTHREAD_H, because the backtrace code
          uses mutexes. Fixes bug 31614; bugfix on 0.2.5.2-alpha.
        - Disable backtrace signal handlers when shutting down tor. Fixes
          bug 31614; bugfix on 0.2.5.2-alpha.
        - Rate-limit the logging message about the obsolete .exit
          notation. Previously, there was no limit on this warning, which
          could potentially be triggered many times by a hostile website.
          Fixes bug 31466; bugfix on 0.2.2.1-alpha.
        - When initialising log domain masks, only set known log domains.
          Fixes bug 31854; bugfix on 0.2.1.1-alpha.
        - Change log level of message "Hash of session info was not as
          expected" to LOG_PROTOCOL_WARN. Fixes bug 12399; bugfix
          on 0.1.1.10-alpha.
        - Fix a code issue that would have broken our parsing of log domains
          as soon as we had 33 of them. Fortunately, we still only have 29.
          Fixes bug 31451; bugfix on 0.4.1.4-rc.
    
      o Minor bugfixes (logging, protocol violations):
        - Do not log a nonfatal assertion failure when receiving a VERSIONS
          cell on a connection using the obsolete v1 link protocol. Log a
          protocol_warn instead. Fixes bug 31107; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (mainloop, periodic events, in-process API):
        - Reset the periodic events' "enabled" flag when Tor is shut down
          cleanly. Previously, this flag was left on, which caused periodic
          events not to be re-enabled when Tor was relaunched in-process
          with tor_api.h after a shutdown. Fixes bug 32058; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (memory management):
        - Stop leaking a small amount of memory in nt_service_install(), in
          unreachable code. Fixes bug 30799; bugfix on 0.2.0.7-alpha. Patch
          by Xiaoyin Liu.
    
      o Minor bugfixes (modules):
        - Explain what the optional Directory Authority module is, and what
          happens when it is disabled. Fixes bug 31825; bugfix
          on 0.3.4.1-alpha.
    
      o Minor bugfixes (multithreading):
        - Avoid some undefined behaviour when freeing mutexes. Fixes bug
          31736; bugfix on 0.0.7.
    
      o Minor bugfixes (networking, IP addresses):
        - When parsing addresses via Tor's internal DNS lookup API, reject
          IPv4 addresses in square brackets, and accept IPv6 addresses in
          square brackets. This change completes the work started in 23082,
          making address parsing consistent between tor's internal DNS
          lookup and address parsing APIs. Fixes bug 30721; bugfix
          on 0.2.1.5-alpha.
        - When parsing addresses via Tor's internal address:port parsing and
          DNS lookup APIs, require IPv6 addresses with ports to have square
          brackets. But allow IPv6 addresses without ports, whether or not
          they have square brackets. Fixes bug 30721; bugfix
          on 0.2.1.5-alpha.
    
      o Minor bugfixes (onion service v3):
        - When purging the client descriptor cache, close any introduction
          point circuits associated with purged cache entries. This avoids
          picking those circuits later when connecting to the same
          introduction points. Fixes bug 30921; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion services):
        - In the hs_ident_circuit_t data structure, remove the unused field
          circuit_type and the respective argument in hs_ident_circuit_new().
          This field was set by clients (for introduction) and services (for
          introduction and rendezvous) but was never used afterwards. Fixes
          bug 31490; bugfix on 0.3.2.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (operator tools):
        - Make tor-print-ed-signing-cert(1) print certificate expiration
          date in RFC 1123 and UNIX timestamp formats, to make output
          machine readable. Fixes bug 31012; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (process management):
        - Remove overly strict assertions that triggered when a pluggable
          transport failed to launch. Fixes bug 31091; bugfix
          on 0.4.0.1-alpha.
        - Remove an assertion in the Unix process backend. This assertion
          would trigger when we failed to find the executable for a child
          process. Fixes bug 31810; bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (relay):
        - Avoid crashing when starting with a corrupt keys directory where
          the old ntor key and the new ntor key are identical. Fixes bug
          30916; bugfix on 0.2.4.8-alpha.
    
      o Minor bugfixes (rust):
        - Correctly exclude a redundant rust build job in Travis. Fixes bug
          31463; bugfix on 0.3.5.4-alpha.
        - Raise the minimum rustc version to 1.31.0, as checked by configure
          and CI. Fixes bug 31442; bugfix on 0.3.5.4-alpha.
    
      o Minor bugfixes (sendme, code structure):
        - Rename the trunnel SENDME file definition from sendme.trunnel to
          sendme_cell.trunnel to avoid having twice sendme.{c|h} in the
          repository. Fixes bug 30769; bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (statistics):
        - Stop removing the ed25519 signature if the extra info file is too
          big. If the signature data was removed, but the keyword was kept,
          this could result in an unparseable extra info file. Fixes bug
          30958; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (subsystems):
        - Make the subsystem init order match the subsystem module
          dependencies. Call windows process security APIs as early as
          possible. Initialize logging before network and time, so that
          network and time can use logging. Fixes bug 31615; bugfix
          on 0.4.0.1-alpha.
    
      o Minor bugfixes (testing):
        - Avoid intermittent test failures due to a test that had relied on
          inconsistent timing sources. Fixes bug 31995; bugfix
          on 0.3.1.3-alpha.
        - When testing port rebinding, don't busy-wait for tor to log.
          Instead, actually sleep for a short time before polling again.
          Also improve the formatting of control commands and log messages.
          Fixes bug 31837; bugfix on 0.3.5.1-alpha.
        - Teach the util/socketpair_ersatz test to work correctly when we
          have no network stack configured. Fixes bug 30804; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (tests, SunOS):
        - Avoid a map_anon_nofork test failure due to a signed/unsigned
          integer comparison. Fixes bug 31897; bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (tls, logging):
        - Log bugs about the TLS read buffer's length only once, rather than
          filling the logs with similar warnings. Fixes bug 31939; bugfix
          on 0.3.0.4-rc.
    
      o Minor bugfixes (v2 single onion services):
        - Always retry v2 single onion service intro and rend circuits with
          a 3-hop path. Previously, v2 single onion services used a 3-hop
          path when rendezvous circuits were retried after a remote or
          delayed failure, but a 1-hop path for immediate retries. Fixes bug
          23818; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (v3 onion services):
        - When cleaning up intro circuits for a v3 onion service, don't
          remove circuits that have an established or pending circuit, even
          if they ran out of retries. This way, we don't remove a circuit on
          its last retry. Fixes bug 31652; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (v3 single onion services):
        - Always retry v3 single onion service intro and rend circuits with
          a 3-hop path. Previously, v3 single onion services used a 3-hop
          path when rend circuits were retried after a remote or delayed
          failure, but a 1-hop path for immediate retries. Fixes bug 23818;
          bugfix on 0.3.2.1-alpha.
        - Make v3 single onion services fall back to a 3-hop intro, when all
          intro points are unreachable via a 1-hop path. Previously, v3
          single onion services failed when all intro nodes were unreachable
          via a 1-hop path. Fixes bug 23507; bugfix on 0.3.2.1-alpha.
    
      o Code simplification and refactoring:
        - Refactor connection_control_process_inbuf() to reduce the size of
          a practracker exception. Closes ticket 31840.
        - Refactor the microdescs_parse_from_string() function into smaller
          pieces, for better comprehensibility. Closes ticket 31675.
        - Use SEVERITY_MASK_IDX() to find the LOG_* mask indexes in the unit
          tests and fuzzers, rather than using hard-coded values. Closes
          ticket 31334.
        - Interface for function `decrypt_desc_layer` cleaned up. Closes
          ticket 31589.
    
      o Documentation:
        - Correct the description of "GuardLifetime". Fixes bug 31189;
          bugfix on 0.3.0.1-alpha.
        - Make clear in the man page, in both the bandwidth section and the
          AccountingMax section, that Tor counts in powers of two, not
          powers of ten: 1 GByte is 1024*1024*1024 bytes, not one billion
          bytes. Resolves ticket 32106.
        - Document the signal-safe logging behaviour in the tor man page.
          Also add some comments to the relevant functions. Closes
          ticket 31839.
        - Explain why we can't destroy the backtrace buffer mutex. Explain
          why we don't need to destroy the log mutex. Closes ticket 31736.
        - The Tor source code repository now includes a (somewhat dated)
          description of Tor's modular architecture, in doc/HACKING/design.
          This is based on the old "tor-guts.git" repository, which we are
          adopting and superseding. Closes ticket 31849.
        - Improve documentation in circuit padding subsystem. Patch by
          Tobias Pulls. Closes ticket 31113.
        - Include an example usage for IPv6 ORPort in our sample torrc.
          Closes ticket 31320; patch from Ali Raheem.
        - Use RFC 2397 data URL scheme to embed an image into tor-exit-
          notice.html so that operators no longer have to host it
          themselves. Closes ticket 31089.
    
      o Removed features:
        - No longer include recommended package digests in votes as detailed
          in proposal 301. The RecommendedPackages torrc option is
          deprecated and will no longer have any effect. "package" lines
          will still be considered when computing consensuses for consensus
          methods that include them. (This change has no effect on the list
          of recommended Tor versions, which is still in use.) Closes
          ticket 29738.
        - Remove torctl.in from contrib/dist directory. Resolves
          ticket 30550.
    
      o Testing:
        - Require C99 standards-conforming code in Travis CI, but allow GNU
          gcc extensions. Also activates clang's -Wtypedef-redefinition
          warnings. Build some jobs with -std=gnu99, and some jobs without.
          Closes ticket 32500.
        - Run shellcheck for all non-third-party shell scripts that are
          shipped with Tor. Closes ticket 29533.
        - When checking shell scripts, ignore any user-created directories.
          Closes ticket 30967.
    
      o Code simplification and refactoring (config handling):
        - Extract our variable manipulation code from confparse.c to a new
          lower-level typedvar.h module. Closes ticket 30864.
        - Lower another layer of object management from confparse.c to a
          more general tool. Now typed structure members are accessible via
          an abstract type. Implements ticket 30914.
        - Move our backend logic for working with configuration and state
          files into a lower-level library, since it no longer depends on
          any tor-specific functionality. Closes ticket 31626.
        - Numerous simplifications in configuration-handling logic: remove
          duplicated macro definitions, replace magical names with flags,
          and refactor "TestingTorNetwork" to use the same default-option
          logic as the rest of Tor. Closes ticket 30935.
        - Replace our ad-hoc set of flags for configuration variables and
          configuration variable types with fine-grained orthogonal flags
          corresponding to the actual behavior we want. Closes ticket 31625.
    
      o Code simplification and refactoring (misc):
        - Eliminate some uses of lower-level control reply abstractions,
          primarily in the onion_helper functions. Closes ticket 30889.
        - Rework bootstrap tracking to use the new publish-subscribe
          subsystem. Closes ticket 29976.
        - Rewrite format_node_description() and router_get_verbose_nickname()
          to use strlcpy() and strlcat(). The previous implementation used
          memcpy() and pointer arithmetic, which was error-prone. Closes
          ticket 31545. This is CID 1452819.
        - Split extrainfo_dump_to_string() into smaller functions. Closes
          ticket 30956.
        - Use the ptrdiff_t type consistently for expressing variable
          offsets and pointer differences. Previously we incorrectly (but
          harmlessly) used int and sometimes off_t for these cases. Closes
          ticket 31532.
        - Use the subsystems mechanism to manage the main event loop code.
          Closes ticket 30806.
        - Various simplifications and minor improvements to the circuit
          padding machines. Patch by Tobias Pulls. Closes tickets 31112
          and 31098.
    
      o Documentation (hard-coded directories):
        - Improve the documentation for the DirAuthority and FallbackDir
          torrc options. Closes ticket 30955.
    
      o Documentation (tor.1 man page):
        - Fix typo in tor.1 man page: the option is "--help", not "-help".
          Fixes bug 31008; bugfix on 0.2.2.9-alpha.
    
      o Testing (continuous integration):
        - Use Ubuntu Bionic images for our Travis CI builds, so we can get a
          recent version of coccinelle. But leave chutney on Ubuntu Trusty,
          until we can fix some Bionic permissions issues (see ticket
          32240). Related to ticket 31919.
        - Install the mingw OpenSSL package in Appveyor. This makes sure
          that the OpenSSL headers and libraries match in Tor's Appveyor
          builds. (This bug was triggered by an Appveyor image update.)
          Fixes bug 32449; bugfix on 0.3.5.6-rc.
        - In Travis, use Xcode 11.2 on macOS 10.14. Closes ticket 32241.
    
    
    Changes in version 0.4.1.7 - 2019-12-09
      This release backports several bugfixes to improve stability and
      correctness.  Anyone experiencing build problems or crashes with 0.4.1.6,
      including all relays relying on AccountingMax, should upgrade.
    
      o Major features (directory authorities, backport from 0.4.2.2-alpha):
        - Directory authorities now reject relays running all currently
          deprecated release series. The currently supported release series
          are: 0.2.9, 0.3.5, 0.4.0, 0.4.1, and 0.4.2. Closes ticket 31549.
    
      o Major bugfixes (embedded Tor, backport from 0.4.2.2-alpha):
        - Avoid a possible crash when restarting Tor in embedded mode and
          enabling a different set of publish/subscribe messages. Fixes bug
          31898; bugfix on 0.4.1.1-alpha.
    
      o Major bugfixes (relay, backport from 0.4.2.3-alpha):
        - Relays now respect their AccountingMax bandwidth again. When
          relays entered "soft" hibernation (which typically starts when
          we've hit 90% of our AccountingMax), we had stopped checking
          whether we should enter hard hibernation. Soft hibernation refuses
          new connections and new circuits, but the existing circuits can
          continue, meaning that relays could have exceeded their configured
          AccountingMax. Fixes bug 32108; bugfix on 0.4.0.1-alpha.
    
      o Major bugfixes (torrc parsing, backport from 0.4.2.2-alpha):
        - Stop ignoring torrc options after an %include directive, when the
          included directory ends with a file that does not contain any
          config options (but does contain comments or whitespace). Fixes
          bug 31408; bugfix on 0.3.1.1-alpha.
    
      o Major bugfixes (v3 onion services, backport from 0.4.2.3-alpha):
        - Onion services now always use the exact number of intro points
          configured with the HiddenServiceNumIntroductionPoints option (or
          fewer if nodes are excluded). Before, a service could sometimes
          pick more intro points than configured. Fixes bug 31548; bugfix
          on 0.3.2.1-alpha.
    
      o Minor features (continuous integration, backport from 0.4.2.2-alpha):
        - When building on Appveyor and Travis, pass the "-k" flag to make,
          so that we are informed of all compilation failures, not just the
          first one or two. Closes ticket 31372.
    
      o Minor features (geoip, backport from 0.4.2.5):
        - Update geoip and geoip6 to the December 3 2019 Maxmind GeoLite2
          Country database. Closes ticket 32685.
    
      o Minor bugfixes (Appveyor CI, backport from 0.4.2.2-alpha):
        - Avoid spurious errors when Appveyor CI fails before the install step.
          Fixes bug 31884; bugfix on 0.3.4.2-alpha.
    
      o Minor bugfixes (client, onion service v3, backport from 0.4.2.4-rc):
        - Fix a BUG() assertion that occurs within a very small race window
          between when a client intro circuit opens and when its descriptor
          gets cleaned up from the cache. The circuit is now closed early,
          which will trigger a re-fetch of the descriptor and continue the
          connection. Fixes bug 28970; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (connections, backport from 0.4.2.3-rc):
        - Avoid trying to read data from closed connections, which can cause
          needless loops in Libevent and infinite loops in Shadow. Fixes bug
          30344; bugfix on 0.1.1.1-alpha.
    
      o Minor bugfixes (error handling, backport from 0.4.2.1-alpha):
        - On abort, try harder to flush the output buffers of log messages.
          On some platforms (macOS), log messages could be discarded when
          the process terminates. Fixes bug 31571; bugfix on 0.3.5.1-alpha.
        - Report the tor version whenever an assertion fails. Previously, we
          only reported the Tor version on some crashes, and some non-fatal
          assertions. Fixes bug 31571; bugfix on 0.3.5.1-alpha.
        - When tor aborts due to an error, close log file descriptors before
          aborting. Closing the logs makes some OSes flush log file buffers,
          rather than deleting buffered log lines. Fixes bug 31594; bugfix
          on 0.2.5.2-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.2.2-alpha):
        - Add a missing check for HAVE_PTHREAD_H, because the backtrace code
          uses mutexes. Fixes bug 31614; bugfix on 0.2.5.2-alpha.
        - Disable backtrace signal handlers when shutting down tor. Fixes
          bug 31614; bugfix on 0.2.5.2-alpha.
        - Rate-limit the logging message about the obsolete .exit
          notation. Previously, there was no limit on this warning, which
          could potentially be triggered many times by a hostile website.
          Fixes bug 31466; bugfix on 0.2.2.1-alpha.
    
      o Minor bugfixes (logging, protocol violations, backport from 0.4.2.2-alpha):
        - Do not log a nonfatal assertion failure when receiving a VERSIONS
          cell on a connection using the obsolete v1 link protocol. Log a
          protocol_warn instead. Fixes bug 31107; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (mainloop, periodic events, in-process API, backport from 0.4.2.3-alpha):
        - Reset the periodic events' "enabled" flag when Tor is shut down
          cleanly. Previously, this flag was left on, which caused periodic
          events not to be re-enabled when Tor was relaunched in-process
          with tor_api.h after a shutdown. Fixes bug 32058; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (multithreading, backport from 0.4.2.2-alpha):
        - Avoid some undefined behaviour when freeing mutexes. Fixes bug
          31736; bugfix on 0.0.7.
    
      o Minor bugfixes (process management, backport from 0.4.2.3-alpha):
        - Remove overly strict assertions that triggered when a pluggable
          transport failed to launch. Fixes bug 31091; bugfix
          on 0.4.0.1-alpha.
        - Remove an assertion in the Unix process backend. This assertion
          would trigger when we failed to find the executable for a child
          process. Fixes bug 31810; bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (relay, backport from 0.4.2.2-alpha):
        - Avoid crashing when starting with a corrupt keys directory where
          the old ntor key and the new ntor key are identical. Fixes bug
          30916; bugfix on 0.2.4.8-alpha.
    
      o Minor bugfixes (testing, backport from 0.4.2.3-alpha):
        - When testing port rebinding, don't busy-wait for tor to log.
          Instead, actually sleep for a short time before polling again.
          Also improve the formatting of control commands and log messages.
          Fixes bug 31837; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (tests, SunOS, backport from 0.4.2.2-alpha):
        - Avoid a map_anon_nofork test failure due to a signed/unsigned
          integer comparison. Fixes bug 31897; bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (tls, logging, backport from 0.4.2.3-alpha):
        - Log bugs about the TLS read buffer's length only once, rather than
          filling the logs with similar warnings. Fixes bug 31939; bugfix
          on 0.3.0.4-rc.
    
      o Documentation (backport from 0.4.2.2-alpha):
        - Explain why we can't destroy the backtrace buffer mutex. Explain
          why we don't need to destroy the log mutex. Closes ticket 31736.
    
      o Testing (continuous integration, backport from 0.4.2.3-alpha):
        - Disable all but one Travis CI macOS build, to mitigate slow
          scheduling of Travis macOS jobs. Closes ticket 32177.
        - Run the chutney IPv6 networks as part of Travis CI. Closes
          ticket 30860.
        - Simplify the Travis CI build matrix, and optimise for build time.
          Closes ticket 31859.
        - Use Windows Server 2019 instead of Windows Server 2016 in our
          Appveyor builds. Closes ticket 32086.
    
      o Testing (continuous integration, backport from 0.4.2.4-rc):
        - In Travis, use Xcode 11.2 on macOS 10.14. Closes ticket 32241.
        - Use Ubuntu Bionic images for our Travis CI builds, so we can get a
          recent version of coccinelle. But leave chutney on Ubuntu Trusty,
          until we can fix some Bionic permissions issues (see ticket
          32240). Related to ticket 31919.
        - Install the mingw OpenSSL package in Appveyor. This makes sure
          that the OpenSSL headers and libraries match in Tor's Appveyor
          builds. (This bug was triggered by an Appveyor image update.)
          Fixes bug 32449; bugfix on 0.3.5.6-rc.
    
      o Testing (continuous integration, backport from 0.4.2.5):
        - Require C99 standards-conforming code in Travis CI, but allow GNU gcc
          extensions. Also activates clang's -Wtypedef-redefinition warnings.
          Build some jobs with -std=gnu99, and some jobs without.
          Closes ticket 32500.
    
    
    Changes in version 0.4.0.6 - 2019-12-09
      This is the second stable release in the 0.4.0.x series. This release
      backports several bugfixes to improve stability and correctness.  Anyone
      experiencing build problems or crashes with 0.4.0.5, including all relays
      relying on AccountingMax, should upgrade.
    
      Note that, per our support policy, support for the 0.4.0.x series will end
      on 2 Feb 2020.  Anyone still running 0.4.0.x should plan to upgrade to the
      latest stable release, or downgrade to 0.3.5.x, which will get long-term
      support until 1 Feb 2022.
    
      o Directory authority changes (backport from 0.4.1.5):
        - The directory authority "dizum" has a new IP address. Closes
          ticket 31406.
    
      o Major bugfixes (bridges, backport from 0.4.1.2-alpha):
        - Consider our directory information to have changed when our list
          of bridges changes. Previously, Tor would not re-compute the
          status of its directory information when bridges changed, and
          therefore would not realize that it was no longer able to build
          circuits. Fixes part of bug 29875.
        - Do not count previously configured working bridges towards our
          total of working bridges. Previously, when Tor's list of bridges
          changed, it would think that the old bridges were still usable,
          and delay fetching router descriptors for the new ones. Fixes part
          of bug 29875; bugfix on 0.3.0.1-alpha.
    
      o Major bugfixes (circuit build, guard, backport from 0.4.1.4-rc):
        - When considering upgrading circuits from "waiting for guard" to
          "open", always ignore circuits that are marked for close. Otherwise,
          we can end up in the situation where a subsystem is notified that
          a closing circuit has just opened, leading to undesirable
          behavior. Fixes bug 30871; bugfix on 0.3.0.1-alpha.
    
      o Major bugfixes (Onion service reachability, backport from 0.4.1.3-alpha):
        - Properly clean up the introduction point map when circuits change
          purpose from onion service circuits to pathbias, measurement, or
          other circuit types. This should fix some service-side instances
          of introduction point failure. Fixes bug 29034; bugfix
          on 0.3.2.1-alpha.
    
      o Major bugfixes (onion service v3, backport from 0.4.1.1-alpha):
        - Fix an unreachable bug in which an introduction point could try to
          send an INTRODUCE_ACK with a status code that Trunnel would refuse
          to encode, leading the relay to assert(). We've consolidated the
          ABI values into Trunnel now. Fixes bug 30454; bugfix
          on 0.3.0.1-alpha.
        - Clients can now handle unknown status codes from INTRODUCE_ACK
          cells. (The NACK behavior will stay the same.) This will allow us
          to extend status codes in the future without breaking the normal
          client behavior. Fixes another part of bug 30454; bugfix
          on 0.3.0.1-alpha.
    
      o Major bugfixes (relay, backport from 0.4.2.3-alpha):
        - Relays now respect their AccountingMax bandwidth again. When
          relays entered "soft" hibernation (which typically starts when
          we've hit 90% of our AccountingMax), we had stopped checking
          whether we should enter hard hibernation. Soft hibernation refuses
          new connections and new circuits, but the existing circuits can
          continue, meaning that relays could have exceeded their configured
          AccountingMax. Fixes bug 32108; bugfix on 0.4.0.1-alpha.
    
      o Major bugfixes (torrc parsing, backport from 0.4.2.2-alpha):
        - Stop ignoring torrc options after an %include directive, when the
          included directory ends with a file that does not contain any
          config options (but does contain comments or whitespace). Fixes
          bug 31408; bugfix on 0.3.1.1-alpha.
    
      o Major bugfixes (v3 onion services, backport from 0.4.2.3-alpha):
        - Onion services now always use the exact number of intro points
          configured with the HiddenServiceNumIntroductionPoints option (or
          fewer if nodes are excluded). Before, a service could sometimes
          pick more intro points than configured. Fixes bug 31548; bugfix
          on 0.3.2.1-alpha.
    
      o Minor features (compile-time modules, backport from version 0.4.1.1-alpha):
        - Add a "--list-modules" command to print a list of which compile-
          time modules are enabled. Closes ticket 30452.
    
      o Minor features (continuous integration, backport from 0.4.1.1-alpha):
        - Remove sudo configuration lines from .travis.yml as they are no
          longer needed with current Travis build environment. Resolves
          issue 30213.
    
      o Minor features (continuous integration, backport from 0.4.1.4-rc):
        - Our Travis configuration now uses Chutney to run some network
          integration tests automatically. Closes ticket 29280.
    
      o Minor features (continuous integration, backport from 0.4.2.2-alpha):
        - When building on Appveyor and Travis, pass the "-k" flag to make,
          so that we are informed of all compilation failures, not just the
          first one or two. Closes ticket 31372.
    
      o Minor features (fallback directory list, backport from 0.4.1.4-rc):
        - Replace the 157 fallbacks originally introduced in Tor 0.3.5.6-rc
          in December 2018 (of which ~122 were still functional), with a
          list of 148 fallbacks (70 new, 78 existing, 79 removed) generated
          in June 2019. Closes ticket 28795.
    
      o Minor features (geoip, backport from 0.4.2.5):
        - Update geoip and geoip6 to the December 3 2019 Maxmind GeoLite2
          Country database. Closes ticket 32685.
    
      o Minor features (stem tests, backport from 0.4.2.1-alpha):
        - Change "make test-stem" so it only runs the stem tests that use
          tor. This change makes test-stem faster and more reliable. Closes
          ticket 31554.
    
      o Minor bugfixes (Appveyor CI, backport from 0.4.2.2-alpha):
        - Avoid spurious errors when Appveyor CI fails before the install step.
          Fixes bug 31884; bugfix on 0.3.4.2-alpha.
    
      o Minor bugfixes (build system, backport form 0.4.2.1-alpha):
        - Do not include the deprecated <sys/sysctl.h> on Linux or Windows
          systems. Fixes bug 31673; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (circuit isolation, backport from 0.4.1.3-alpha):
        - Fix a logic error that prevented the SessionGroup sub-option from
          being accepted. Fixes bug 22619; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (circuit padding, backport from 0.4.1.4-rc):
        - On relays, properly check that a padding machine is absent before
          logging a warning about it being absent. Fixes bug 30649; bugfix
          on 0.4.0.1-alpha.
    
      o Minor bugfixes (client, onion service v3, backport from 0.4.2.4-rc):
        - Fix a BUG() assertion that occurs within a very small race window
          between when a client intro circuit opens and when its descriptor
          gets cleaned up from the cache. The circuit is now closed early,
          which will trigger a re-fetch of the descriptor and continue the
          connection. Fixes bug 28970; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (clock skew detection, backport from 0.4.1.5):
        - Don't believe clock skew results from NETINFO cells that appear to
          arrive before we sent the VERSIONS cells they are responding to.
          Previously, we would accept them up to 3 minutes "in the past".
          Fixes bug 31343; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (compilation warning, backport from 0.4.1.5):
        - Fix a compilation warning on Windows about casting a function
          pointer for GetTickCount64(). Fixes bug 31374; bugfix
          on 0.2.9.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.4.1.5):
        - Avoid using labs() on time_t, which can cause compilation warnings
          on 64-bit Windows builds. Fixes bug 31343; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (compilation, backport from 0.4.2.1-alpha):
        - Suppress spurious float-conversion warnings from GCC when calling
          floating-point classifier functions on FreeBSD. Fixes part of bug
          31687; bugfix on 0.3.1.5-alpha.
    
      o Minor bugfixes (compilation, unusual configurations, backport from 0.4.1.1-alpha):
        - Avoid failures when building with the ALL_BUGS_ARE_FATAL option
          due to missing declarations of abort(), and prevent other such
          failures in the future. Fixes bug 30189; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (configuration, proxies, backport from 0.4.1.2-alpha):
        - Fix a bug that prevented us from supporting SOCKS5 proxies that
          want authentication along with configured (but unused!)
          ClientTransportPlugins. Fixes bug 29670; bugfix on 0.2.6.1-alpha.
    
      o Minor bugfixes (connections, backport from 0.4.2.3-rc):
        - Avoid trying to read data from closed connections, which can cause
          needless loops in Libevent and infinite loops in Shadow. Fixes bug
          30344; bugfix on 0.1.1.1-alpha.
    
      o Minor bugfixes (continuous integration, backport from 0.4.1.3-alpha):
        - Allow the test-stem job to fail in Travis, because it sometimes
          hangs. Fixes bug 30744; bugfix on 0.3.5.4-alpha.
        - Skip test_rebind on macOS in Travis, because it is unreliable on
          macOS on Travis. Fixes bug 30713; bugfix on 0.3.5.1-alpha.
        - Skip test_rebind when the TOR_SKIP_TEST_REBIND environment
          variable is set. Fixes bug 30713; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (crash on exit, backport from 0.4.1.4-rc):
        - Avoid a set of possible code paths that could try to use freed
          memory in routerlist_free() while Tor was exiting. Fixes bug
          31003; bugfix on 0.1.2.2-alpha.
    
      o Minor bugfixes (directory authorities, backport from 0.4.1.3-alpha):
        - Stop crashing after parsing an unknown descriptor purpose
          annotation. We think this bug can only be triggered by modifying a
          local file. Fixes bug 30781; bugfix on 0.2.0.8-alpha.
    
      o Minor bugfixes (directory authority, backport from 0.4.1.2-alpha):
        - Move the "bandwidth-file-headers" line in directory authority
          votes so that it conforms to dir-spec.txt. Fixes bug 30316; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (error handling, backport from 0.4.2.1-alpha):
        - On abort, try harder to flush the output buffers of log messages.
          On some platforms (macOS), log messages could be discarded when
          the process terminates. Fixes bug 31571; bugfix on 0.3.5.1-alpha.
        - Report the tor version whenever an assertion fails. Previously, we
          only reported the Tor version on some crashes, and some non-fatal
          assertions. Fixes bug 31571; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (FreeBSD, PF-based proxy, IPv6, backport from 0.4.2.1-alpha):
        - When extracting an IPv6 address from a PF-based proxy, verify that
          we are actually configured to receive an IPv6 address, and log an
          internal error if not. Fixes part of bug 31687; bugfix
          on 0.2.3.4-alpha.
    
      o Minor bugfixes (guards, backport from 0.4.2.1-alpha):
        - When tor is missing descriptors for some primary entry guards,
          make the log message less alarming. It's normal for descriptors to
          expire, as long as tor fetches new ones soon after. Fixes bug
          31657; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.1.1-alpha):
        - Do not log a warning when running with an OpenSSL version other
          than the one Tor was compiled with, if the two versions should be
          compatible. Previously, we would warn whenever the version was
          different. Fixes bug 30190; bugfix on 0.2.4.2-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.2.1-alpha):
        - Change log level of message "Hash of session info was not as
          expected" to LOG_PROTOCOL_WARN. Fixes bug 12399; bugfix
          on 0.1.1.10-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.2.2-alpha):
        - Rate-limit the logging message about the obsolete .exit
          notation. Previously, there was no limit on this warning, which
          could potentially be triggered many times by a hostile website.
          Fixes bug 31466; bugfix on 0.2.2.1-alpha.
    
      o Minor bugfixes (logging, protocol violations, backport from 0.4.2.2-alpha):
        - Do not log a nonfatal assertion failure when receiving a VERSIONS
          cell on a connection using the obsolete v1 link protocol. Log a
          protocol_warn instead. Fixes bug 31107; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (mainloop, periodic events, in-process API, backport from 0.4.2.3-alpha):
        - Reset the periodic events' "enabled" flag when Tor is shut down
          cleanly. Previously, this flag was left on, which caused periodic
          events not to be re-enabled when Tor was relaunched in-process
          with tor_api.h after a shutdown. Fixes bug 32058; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (memory leak, backport from 0.4.1.1-alpha):
        - Avoid a minor memory leak that could occur on relays when failing
          to create a "keys" directory. Fixes bug 30148; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (memory leak, backport from 0.4.1.4-rc):
        - Fix a trivial memory leak when parsing an invalid value
          from a download schedule in the configuration. Fixes bug
          30894; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (NetBSD, backport from 0.4.1.2-alpha):
        - Fix usage of minherit() on NetBSD and other platforms that define
          MAP_INHERIT_{ZERO,NONE} instead of INHERIT_{ZERO,NONE}. Fixes bug
          30614; bugfix on 0.4.0.2-alpha. Patch from Taylor Campbell.
    
      o Minor bugfixes (onion services, backport from 0.4.1.1-alpha):
        - Avoid a GCC 9.1.1 warning (and possible crash depending on libc
          implementation) when failing to load an onion service client
          authorization file. Fixes bug 30475; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (out-of-memory handler, backport from 0.4.1.2-alpha):
        - When purging the DNS cache because of an out-of-memory condition,
          try purging just the older entries at first. Previously, we would
          always purge the whole thing. Fixes bug 29617; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (portability, backport from 0.4.1.2-alpha):
        - Avoid crashing in our tor_vasprintf() implementation on systems
          that define neither vasprintf() nor _vscprintf(). (This bug has
          been here long enough that we question whether people are running
          Tor on such systems, but we're applying the fix out of caution.)
          Fixes bug 30561; bugfix on 0.2.8.2-alpha. Found and fixed by
          Tobias Stoeckmann.
    
      o Minor bugfixes (process management, backport from 0.4.2.3-alpha):
        - Remove overly strict assertions that triggered when a pluggable
          transport failed to launch. Fixes bug 31091; bugfix
          on 0.4.0.1-alpha.
        - Remove an assertion in the Unix process backend. This assertion
          would trigger when we failed to find the executable for a child
          process. Fixes bug 31810; bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (relay, backport from 0.4.2.2-alpha):
        - Avoid crashing when starting with a corrupt keys directory where
          the old ntor key and the new ntor key are identical. Fixes bug
          30916; bugfix on 0.2.4.8-alpha.
    
      o Minor bugfixes (rust, backport from 0.4.2.1-alpha):
        - Correctly exclude a redundant rust build job in Travis. Fixes bug
          31463; bugfix on 0.3.5.4-alpha.
    
      o Minor bugfixes (testing, backport from 0.4.2.3-alpha):
        - When testing port rebinding, don't busy-wait for tor to log.
          Instead, actually sleep for a short time before polling again.
          Also improve the formatting of control commands and log messages.
          Fixes bug 31837; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (tls, logging, backport from 0.4.2.3-alpha):
        - Log bugs about the TLS read buffer's length only once, rather than
          filling the logs with similar warnings. Fixes bug 31939; bugfix
          on 0.3.0.4-rc.
    
      o Minor bugfixes (v2 single onion services, backport from 0.4.2.1-alpha):
        - Always retry v2 single onion service intro and rend circuits with
          a 3-hop path. Previously, v2 single onion services used a 3-hop
          path when rendezvous circuits were retried after a remote or
          delayed failure, but a 1-hop path for immediate retries. Fixes bug
          23818; bugfix on 0.2.9.3-alpha.
        - Make v3 single onion services fall back to a 3-hop intro, when all
          intro points are unreachable via a 1-hop path. Previously, v3
          single onion services failed when all intro nodes were unreachable
          via a 1-hop path. Fixes bug 23507; bugfix on 0.3.2.1-alpha.
    
      o Documentation (backport from 0.4.2.1-alpha):
        - Use RFC 2397 data URL scheme to embed an image into tor-exit-
          notice.html so that operators no longer have to host it
          themselves. Closes ticket 31089.
    
      o Testing (backport from 0.4.1.2-alpha):
        - Specify torrc paths (with empty files) when launching tor in
          integration tests; refrain from reading user and system torrcs.
          Resolves issue 29702.
    
      o Testing (continuous integration, backport from 0.4.1.1-alpha):
        - In Travis, show stem's tor log after failure. Closes ticket 30234.
    
      o Testing (continuous integration, backport from 0.4.1.5):
        - In Travis, make stem log a controller trace to the console, and
          tail stem's tor log after failure. Closes ticket 30591.
        - In Travis, only run the stem tests that use a tor binary. Closes
          ticket 30694.
    
      o Testing (continuous integration, backport from 0.4.2.3-alpha):
        - Disable all but one Travis CI macOS build, to mitigate slow
          scheduling of Travis macOS jobs. Closes ticket 32177.
        - Run the chutney IPv6 networks as part of Travis CI. Closes
          ticket 30860.
        - Simplify the Travis CI build matrix, and optimise for build time.
          Closes ticket 31859.
        - Use Windows Server 2019 instead of Windows Server 2016 in our
          Appveyor builds. Closes ticket 32086.
    
      o Testing (continuous integration, backport from 0.4.2.4-rc):
        - Use Ubuntu Bionic images for our Travis CI builds, so we can get a
          recent version of coccinelle. But leave chutney on Ubuntu Trusty,
          until we can fix some Bionic permissions issues (see ticket
          32240). Related to ticket 31919.
        - Install the mingw OpenSSL package in Appveyor. This makes sure
          that the OpenSSL headers and libraries match in Tor's Appveyor
          builds. (This bug was triggered by an Appveyor image update.)
          Fixes bug 32449; bugfix on 0.3.5.6-rc.
        - In Travis, use Xcode 11.2 on macOS 10.14. Closes ticket 32241.
    
      o Testing (continuous integration, backport from 0.4.2.5):
        - Require C99 standards-conforming code in Travis CI, but allow GNU gcc
          extensions. Also activates clang's -Wtypedef-redefinition warnings.
          Build some jobs with -std=gnu99, and some jobs without.
          Closes ticket 32500.
    
    
    Changes in version 0.3.5.9 - 2019-12-09
      Tor 0.3.5.9 backports serveral fixes from later releases, including
      several that affect bridge users, relay stability, onion services,
      and much more.
    
      o Directory authority changes (backport from 0.4.1.5):
        - The directory authority "dizum" has a new IP address. Closes
          ticket 31406.
    
      o Major bugfixes (bridges, backport from 0.4.1.2-alpha):
        - Consider our directory information to have changed when our list
          of bridges changes. Previously, Tor would not re-compute the
          status of its directory information when bridges changed, and
          therefore would not realize that it was no longer able to build
          circuits. Fixes part of bug 29875.
        - Do not count previously configured working bridges towards our
          total of working bridges. Previously, when Tor's list of bridges
          changed, it would think that the old bridges were still usable,
          and delay fetching router descriptors for the new ones. Fixes part
          of bug 29875; bugfix on 0.3.0.1-alpha.
    
      o Major bugfixes (circuit build, guard, backport from 0.4.1.4-rc):
        - When considering upgrading circuits from "waiting for guard" to
          "open", always ignore circuits that are marked for close. Otherwise,
          we can end up in the situation where a subsystem is notified that
          a closing circuit has just opened, leading to undesirable
          behavior. Fixes bug 30871; bugfix on 0.3.0.1-alpha.
    
      o Major bugfixes (NSS, relay, backport from 0.4.0.4-rc):
        - When running with NSS, disable TLS 1.2 ciphersuites that use
          SHA384 for their PRF. Due to an NSS bug, the TLS key exporters for
          these ciphersuites don't work -- which caused relays to fail to
          handshake with one another when these ciphersuites were enabled.
          Fixes bug 29241; bugfix on 0.3.5.1-alpha.
    
      o Major bugfixes (Onion service reachability, backport from 0.4.1.3-alpha):
        - Properly clean up the introduction point map when circuits change
          purpose from onion service circuits to pathbias, measurement, or
          other circuit types. This should fix some service-side instances
          of introduction point failure. Fixes bug 29034; bugfix
          on 0.3.2.1-alpha.
    
      o Major bugfixes (onion service v3, backport from 0.4.1.1-alpha):
        - Fix an unreachable bug in which an introduction point could try to
          send an INTRODUCE_ACK with a status code that Trunnel would refuse
          to encode, leading the relay to assert(). We've consolidated the
          ABI values into Trunnel now. Fixes bug 30454; bugfix
          on 0.3.0.1-alpha.
        - Clients can now handle unknown status codes from INTRODUCE_ACK
          cells. (The NACK behavior will stay the same.) This will allow us
          to extend status codes in the future without breaking the normal
          client behavior. Fixes another part of bug 30454; bugfix
          on 0.3.0.1-alpha.
    
      o Major bugfixes (torrc parsing, backport from 0.4.2.2-alpha):
        - Stop ignoring torrc options after an %include directive, when the
          included directory ends with a file that does not contain any
          config options (but does contain comments or whitespace). Fixes
          bug 31408; bugfix on 0.3.1.1-alpha.
    
      o Major bugfixes (v3 onion services, backport from 0.4.2.3-alpha):
        - Onion services now always use the exact number of intro points
          configured with the HiddenServiceNumIntroductionPoints option (or
          fewer if nodes are excluded). Before, a service could sometimes
          pick more intro points than configured. Fixes bug 31548; bugfix
          on 0.3.2.1-alpha.
    
      o Minor features (address selection, backport from 0.4.0.3-alpha):
        - Treat the subnet 100.64.0.0/10 as public for some purposes;
          private for others. This subnet is the RFC 6598 (Carrier Grade
          NAT) IP range, and is deployed by many ISPs as an alternative to
          RFC 1918 that does not break existing internal networks. Tor now
          blocks SOCKS and control ports on these addresses and warns users
          if client ports or ExtORPorts are listening on a RFC 6598 address.
          Closes ticket 28525. Patch by Neel Chauhan.
    
      o Minor features (bandwidth authority, backport from 0.4.0.4-rc):
        - Make bandwidth authorities ignore relays that are reported in the
          bandwidth file with the flag "vote=0". This change allows us to
          report unmeasured relays for diagnostic reasons without including
          their bandwidth in the bandwidth authorities' vote. Closes
          ticket 29806.
    
      o Minor features (compile-time modules, backport from version 0.4.1.1-alpha):
        - Add a "--list-modules" command to print a list of which compile-
          time modules are enabled. Closes ticket 30452.
    
      o Minor features (continuous integration, backport from 0.4.0.4-rc):
        - On Travis Rust builds, cleanup Rust registry and refrain from
          caching the "target/" directory to speed up builds. Resolves
          issue 29962.
    
      o Minor features (continuous integration, backport from 0.4.0.5):
        - In Travis, tell timelimit to use stem's backtrace signals, and
          launch python directly from timelimit, so python receives the
          signals from timelimit, rather than make. Closes ticket 30117.
    
      o Minor features (continuous integration, backport from 0.4.1.1-alpha):
        - Remove sudo configuration lines from .travis.yml as they are no
          longer needed with current Travis build environment. Resolves
          issue 30213.
    
      o Minor features (continuous integration, backport from 0.4.1.4-rc):
        - Our Travis configuration now uses Chutney to run some network
          integration tests automatically. Closes ticket 29280.
    
      o Minor features (continuous integration, backport from 0.4.2.2-alpha):
        - When building on Appveyor and Travis, pass the "-k" flag to make,
          so that we are informed of all compilation failures, not just the
          first one or two. Closes ticket 31372.
    
      o Minor features (fallback directory list, backport from 0.4.1.4-rc):
        - Replace the 157 fallbacks originally introduced in Tor 0.3.5.6-rc
          in December 2018 (of which ~122 were still functional), with a
          list of 148 fallbacks (70 new, 78 existing, 79 removed) generated
          in June 2019. Closes ticket 28795.
    
      o Minor features (geoip, backport from 0.4.2.5):
        - Update geoip and geoip6 to the December 3 2019 Maxmind GeoLite2
          Country database. Closes ticket 32685.
    
      o Minor features (NSS, diagnostic, backport from 0.4.0.4-rc):
        - Try to log an error from NSS (if there is any) and a more useful
          description of our situation if we are using NSS and a call to
          SSL_ExportKeyingMaterial() fails. Diagnostic for ticket 29241.
    
      o Minor features (stem tests, backport from 0.4.2.1-alpha):
        - Change "make test-stem" so it only runs the stem tests that use
          tor. This change makes test-stem faster and more reliable. Closes
          ticket 31554.
    
      o Minor bugfixes (security, backport from 0.4.0.4-rc):
        - Verify in more places that we are not about to create a buffer
          with more than INT_MAX bytes, to avoid possible OOB access in the
          event of bugs. Fixes bug 30041; bugfix on 0.2.0.16. Found and
          fixed by Tobias Stoeckmann.
        - Fix a potential double free bug when reading huge bandwidth files.
          The issue is not exploitable in the current Tor network because
          the vulnerable code is only reached when directory authorities
          read bandwidth files, but bandwidth files come from a trusted
          source (usually the authorities themselves). Furthermore, the
          issue is only exploitable in rare (non-POSIX) 32-bit architectures,
          which are not used by any of the current authorities. Fixes bug
          30040; bugfix on 0.3.5.1-alpha. Bug found and fixed by
          Tobias Stoeckmann.
    
      o Minor bugfix (continuous integration, backport from 0.4.0.4-rc):
        - Reset coverage state on disk after Travis CI has finished. This
          should prevent future coverage merge errors from causing the test
          suite for the "process" subsystem to fail. The process subsystem
          was introduced in 0.4.0.1-alpha. Fixes bug 29036; bugfix
          on 0.2.9.15.
        - Terminate test-stem if it takes more than 9.5 minutes to run.
          (Travis terminates the job after 10 minutes of no output.)
          Diagnostic for 29437. Fixes bug 30011; bugfix on 0.3.5.4-alpha.
    
      o Minor bugfixes (Appveyor CI, backport from 0.4.2.2-alpha):
        - Avoid spurious errors when Appveyor CI fails before the install step.
          Fixes bug 31884; bugfix on 0.3.4.2-alpha.
    
      o Minor bugfixes (build system, backport form 0.4.2.1-alpha):
        - Do not include the deprecated <sys/sysctl.h> on Linux or Windows
          systems. Fixes bug 31673; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (C correctness, backport from 0.4.0.4-rc):
        - Fix an unlikely memory leak in consensus_diff_apply(). Fixes bug
          29824; bugfix on 0.3.1.1-alpha. This is Coverity warning
          CID 1444119.
    
      o Minor bugfixes (circuit isolation, backport from 0.4.1.3-alpha):
        - Fix a logic error that prevented the SessionGroup sub-option from
          being accepted. Fixes bug 22619; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (client, onion service v3, backport from 0.4.2.4-rc):
        - Fix a BUG() assertion that occurs within a very small race window
          between when a client intro circuit opens and when its descriptor
          gets cleaned up from the cache. The circuit is now closed early,
          which will trigger a re-fetch of the descriptor and continue the
          connection. Fixes bug 28970; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (clock skew detection, backport from 0.4.1.5):
        - Don't believe clock skew results from NETINFO cells that appear to
          arrive before we sent the VERSIONS cells they are responding to.
          Previously, we would accept them up to 3 minutes "in the past".
          Fixes bug 31343; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (compilation warning, backport from 0.4.1.5):
        - Fix a compilation warning on Windows about casting a function
          pointer for GetTickCount64(). Fixes bug 31374; bugfix
          on 0.2.9.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.4.0.2-alpha):
        - Silence a compiler warning in test-memwipe.c on OpenBSD. Fixes bug
          29145; bugfix on 0.2.9.3-alpha. Patch from Kris Katterjohn.
    
      o Minor bugfixes (compilation, backport from 0.4.1.5):
        - Avoid using labs() on time_t, which can cause compilation warnings
          on 64-bit Windows builds. Fixes bug 31343; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (compilation, backport from 0.4.2.1-alpha):
        - Suppress spurious float-conversion warnings from GCC when calling
          floating-point classifier functions on FreeBSD. Fixes part of bug
          31687; bugfix on 0.3.1.5-alpha.
    
      o Minor bugfixes (compilation, unusual configurations, backport from 0.4.1.1-alpha):
        - Avoid failures when building with the ALL_BUGS_ARE_FATAL option
          due to missing declarations of abort(), and prevent other such
          failures in the future. Fixes bug 30189; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (configuration, proxies, backport from 0.4.1.2-alpha):
        - Fix a bug that prevented us from supporting SOCKS5 proxies that
          want authentication along with configured (but unused!)
          ClientTransportPlugins. Fixes bug 29670; bugfix on 0.2.6.1-alpha.
    
      o Minor bugfixes (connections, backport from 0.4.2.3-rc):
        - Avoid trying to read data from closed connections, which can cause
          needless loops in Libevent and infinite loops in Shadow. Fixes bug
          30344; bugfix on 0.1.1.1-alpha.
    
      o Minor bugfixes (continuous integration, backport from 0.4.1.3-alpha):
        - Allow the test-stem job to fail in Travis, because it sometimes
          hangs. Fixes bug 30744; bugfix on 0.3.5.4-alpha.
        - Skip test_rebind on macOS in Travis, because it is unreliable on
          macOS on Travis. Fixes bug 30713; bugfix on 0.3.5.1-alpha.
        - Skip test_rebind when the TOR_SKIP_TEST_REBIND environment
          variable is set. Fixes bug 30713; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (crash on exit, backport from 0.4.1.4-rc):
        - Avoid a set of possible code paths that could try to use freed
          memory in routerlist_free() while Tor was exiting. Fixes bug
          31003; bugfix on 0.1.2.2-alpha.
    
      o Minor bugfixes (directory authorities, backport from 0.4.1.3-alpha):
        - Stop crashing after parsing an unknown descriptor purpose
          annotation. We think this bug can only be triggered by modifying a
          local file. Fixes bug 30781; bugfix on 0.2.0.8-alpha.
    
      o Minor bugfixes (directory authority, backport from 0.4.1.2-alpha):
        - Move the "bandwidth-file-headers" line in directory authority
          votes so that it conforms to dir-spec.txt. Fixes bug 30316; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (error handling, backport from 0.4.2.1-alpha):
        - On abort, try harder to flush the output buffers of log messages.
          On some platforms (macOS), log messages could be discarded when
          the process terminates. Fixes bug 31571; bugfix on 0.3.5.1-alpha.
        - Report the tor version whenever an assertion fails. Previously, we
          only reported the Tor version on some crashes, and some non-fatal
          assertions. Fixes bug 31571; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (FreeBSD, PF-based proxy, IPv6, backport from 0.4.2.1-alpha):
        - When extracting an IPv6 address from a PF-based proxy, verify that
          we are actually configured to receive an IPv6 address, and log an
          internal error if not. Fixes part of bug 31687; bugfix
          on 0.2.3.4-alpha.
    
      o Minor bugfixes (guards, backport from 0.4.2.1-alpha):
        - When tor is missing descriptors for some primary entry guards,
          make the log message less alarming. It's normal for descriptors to
          expire, as long as tor fetches new ones soon after. Fixes bug
          31657; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.0.2-alpha):
        - Avoid logging that we are relaxing a circuit timeout when that
          timeout is fixed. Fixes bug 28698; bugfix on 0.2.4.7-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.0.3-alpha):
        - Correct a misleading error message when IPv4Only or IPv6Only is
          used but the resolved address can not be interpreted as an address
          of the specified IP version. Fixes bug 13221; bugfix on
          0.2.3.9-alpha. Patch from Kris Katterjohn.
        - Log the correct port number for listening sockets when "auto" is
          used to let Tor pick the port number. Previously, port 0 was
          logged instead of the actual port number. Fixes bug 29144; bugfix
          on 0.3.5.1-alpha. Patch from Kris Katterjohn.
        - Stop logging a BUG() warning when Tor is waiting for exit
          descriptors. Fixes bug 28656; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.1.1-alpha):
        - Do not log a warning when running with an OpenSSL version other
          than the one Tor was compiled with, if the two versions should be
          compatible. Previously, we would warn whenever the version was
          different. Fixes bug 30190; bugfix on 0.2.4.2-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.2.1-alpha):
        - Change log level of message "Hash of session info was not as
          expected" to LOG_PROTOCOL_WARN. Fixes bug 12399; bugfix
          on 0.1.1.10-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.2.2-alpha):
        - Rate-limit the logging message about the obsolete .exit
          notation. Previously, there was no limit on this warning, which
          could potentially be triggered many times by a hostile website.
          Fixes bug 31466; bugfix on 0.2.2.1-alpha.
    
      o Minor bugfixes (logging, protocol violations, backport from 0.4.2.2-alpha):
        - Do not log a nonfatal assertion failure when receiving a VERSIONS
          cell on a connection using the obsolete v1 link protocol. Log a
          protocol_warn instead. Fixes bug 31107; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (mainloop, periodic events, in-process API, backport from 0.4.2.3-alpha):
        - Reset the periodic events' "enabled" flag when Tor is shut down
          cleanly. Previously, this flag was left on, which caused periodic
          events not to be re-enabled when Tor was relaunched in-process
          with tor_api.h after a shutdown. Fixes bug 32058; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (memory leak, backport from 0.4.1.1-alpha):
        - Avoid a minor memory leak that could occur on relays when failing
          to create a "keys" directory. Fixes bug 30148; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (memory leak, backport from 0.4.1.4-rc):
        - Fix a trivial memory leak when parsing an invalid value
          from a download schedule in the configuration. Fixes bug
          30894; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (memory management, backport from 0.4.0.3-alpha):
        - Refactor the shared random state's memory management so that it
          actually takes ownership of the shared random value pointers.
          Fixes bug 29706; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (memory management, testing, backport from 0.4.0.3-alpha):
        - Stop leaking parts of the shared random state in the shared-random
          unit tests. Fixes bug 29599; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (onion services, backport from 0.4.1.1-alpha):
        - Avoid a GCC 9.1.1 warning (and possible crash depending on libc
          implementation) when failing to load an onion service client
          authorization file. Fixes bug 30475; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (out-of-memory handler, backport from 0.4.1.2-alpha):
        - When purging the DNS cache because of an out-of-memory condition,
          try purging just the older entries at first. Previously, we would
          always purge the whole thing. Fixes bug 29617; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (portability, backport from 0.4.1.2-alpha):
        - Avoid crashing in our tor_vasprintf() implementation on systems
          that define neither vasprintf() nor _vscprintf(). (This bug has
          been here long enough that we question whether people are running
          Tor on such systems, but we're applying the fix out of caution.)
          Fixes bug 30561; bugfix on 0.2.8.2-alpha. Found and fixed by
          Tobias Stoeckmann.
    
      o Minor bugfixes (relay, backport from 0.4.2.2-alpha):
        - Avoid crashing when starting with a corrupt keys directory where
          the old ntor key and the new ntor key are identical. Fixes bug
          30916; bugfix on 0.2.4.8-alpha.
    
      o Minor bugfixes (rust, backport from 0.4.0.5):
        - Abort on panic in all build profiles, instead of potentially
          unwinding into C code. Fixes bug 27199; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (rust, backport from 0.4.2.1-alpha):
        - Correctly exclude a redundant rust build job in Travis. Fixes bug
          31463; bugfix on 0.3.5.4-alpha.
    
      o Minor bugfixes (single onion services, backport from 0.4.0.3-alpha):
        - Allow connections to single onion services to remain idle without
          being disconnected. Previously, relays acting as rendezvous points
          for single onion services were mistakenly closing idle rendezvous
          circuits after 60 seconds, thinking that they were unused
          directory-fetching circuits that had served their purpose. Fixes
          bug 29665; bugfix on 0.2.1.26.
    
      o Minor bugfixes (stats, backport from 0.4.0.3-alpha):
        - When ExtraInfoStatistics is 0, stop including PaddingStatistics in
          relay and bridge extra-info documents. Fixes bug 29017; bugfix
          on 0.3.1.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.4.0.3-alpha):
        - Downgrade some LOG_ERR messages in the address/* tests to
          warnings. The LOG_ERR messages were occurring when we had no
          configured network. We were failing the unit tests, because we
          backported 28668 to 0.3.5.8, but did not backport 29530. Fixes bug
          29530; bugfix on 0.3.5.8.
        - Fix our gcov wrapper script to look for object files at the
          correct locations. Fixes bug 29435; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.4.0.4-rc):
        - Backport the 0.3.4 src/test/test-network.sh to 0.2.9. We need a
          recent test-network.sh to use new chutney features in CI. Fixes
          bug 29703; bugfix on 0.2.9.1-alpha.
        - Fix a test failure on Windows caused by an unexpected "BUG"
          warning in our tests for tor_gmtime_r(-1). Fixes bug 29922; bugfix
          on 0.2.9.3-alpha.
    
      o Minor bugfixes (testing, backport from 0.4.2.3-alpha):
        - When testing port rebinding, don't busy-wait for tor to log.
          Instead, actually sleep for a short time before polling again.
          Also improve the formatting of control commands and log messages.
          Fixes bug 31837; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (TLS protocol, backport form 0.4.0.4-rc):
        - When classifying a client's selection of TLS ciphers, if the
          client ciphers are not yet available, do not cache the result.
          Previously, we had cached the unavailability of the cipher list
          and never looked again, which in turn led us to assume that the
          client only supported the ancient V1 link protocol. This, in turn,
          was causing Stem integration tests to stall in some cases. Fixes
          bug 30021; bugfix on 0.2.4.8-alpha.
    
      o Minor bugfixes (tls, logging, backport from 0.4.2.3-alpha):
        - Log bugs about the TLS read buffer's length only once, rather than
          filling the logs with similar warnings. Fixes bug 31939; bugfix
          on 0.3.0.4-rc.
    
      o Minor bugfixes (v2 single onion services, backport from 0.4.2.1-alpha):
        - Always retry v2 single onion service intro and rend circuits with
          a 3-hop path. Previously, v2 single onion services used a 3-hop
          path when rendezvous circuits were retried after a remote or
          delayed failure, but a 1-hop path for immediate retries. Fixes bug
          23818; bugfix on 0.2.9.3-alpha.
        - Make v3 single onion services fall back to a 3-hop intro, when all
          intro points are unreachable via a 1-hop path. Previously, v3
          single onion services failed when all intro nodes were unreachable
          via a 1-hop path. Fixes bug 23507; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (Windows, CI, backport from 0.4.0.3-alpha):
        - Skip the Appveyor 32-bit Windows Server 2016 job, and 64-bit
          Windows Server 2012 R2 job. The remaining 2 jobs still provide
          coverage of 64/32-bit, and Windows Server 2016/2012 R2. Also set
          fast_finish, so failed jobs terminate the build immediately. Fixes
          bug 29601; bugfix on 0.3.5.4-alpha.
    
      o Documentation (backport from 0.4.2.1-alpha):
        - Use RFC 2397 data URL scheme to embed an image into tor-exit-
          notice.html so that operators no longer have to host it
          themselves. Closes ticket 31089.
    
      o Testing (backport from 0.4.1.2-alpha):
        - Specify torrc paths (with empty files) when launching tor in
          integration tests; refrain from reading user and system torrcs.
          Resolves issue 29702.
    
      o Testing (continuous integration, backport from 0.4.1.1-alpha):
        - In Travis, show stem's tor log after failure. Closes ticket 30234.
    
      o Testing (continuous integration, backport from 0.4.1.5):
        - In Travis, make stem log a controller trace to the console, and
          tail stem's tor log after failure. Closes ticket 30591.
        - In Travis, only run the stem tests that use a tor binary. Closes
          ticket 30694.
    
      o Testing (continuous integration, backport from 0.4.2.3-alpha):
        - Disable all but one Travis CI macOS build, to mitigate slow
          scheduling of Travis macOS jobs. Closes ticket 32177.
        - Run the chutney IPv6 networks as part of Travis CI. Closes
          ticket 30860.
        - Simplify the Travis CI build matrix, and optimise for build time.
          Closes ticket 31859.
        - Use Windows Server 2019 instead of Windows Server 2016 in our
          Appveyor builds. Closes ticket 32086.
    
      o Testing (continuous integration, backport from 0.4.2.4-rc):
        - Use Ubuntu Bionic images for our Travis CI builds, so we can get a
          recent version of coccinelle. But leave chutney on Ubuntu Trusty,
          until we can fix some Bionic permissions issues (see ticket
          32240). Related to ticket 31919.
        - Install the mingw OpenSSL package in Appveyor. This makes sure
          that the OpenSSL headers and libraries match in Tor's Appveyor
          builds. (This bug was triggered by an Appveyor image update.)
          Fixes bug 32449; bugfix on 0.3.5.6-rc.
        - In Travis, use Xcode 11.2 on macOS 10.14. Closes ticket 32241.
    
      o Testing (continuous integration, backport from 0.4.2.5):
        - Require C99 standards-conforming code in Travis CI, but allow GNU gcc
          extensions. Also activates clang's -Wtypedef-redefinition warnings.
          Build some jobs with -std=gnu99, and some jobs without.
          Closes ticket 32500.
    
    
    Changes in version 0.4.1.6 - 2019-09-19
      This release backports several bugfixes to improve stability and
      correctness.  Anyone experiencing build problems or crashes with 0.4.1.5,
      or experiencing reliability issues with single onion services, should
      upgrade.
    
      o Major bugfixes (crash, Linux, Android, backport from 0.4.2.1-alpha):
        - Tolerate systems (including some Android installations) where
          madvise and MADV_DONTDUMP are available at build-time, but not at
          run time. Previously, these systems would notice a failed syscall
          and abort. Fixes bug 31570; bugfix on 0.4.1.1-alpha.
        - Tolerate systems (including some Linux installations) where
          madvise and/or MADV_DONTFORK are available at build-time, but not
          at run time. Previously, these systems would notice a failed
          syscall and abort. Fixes bug 31696; bugfix on 0.4.1.1-alpha.
    
      o Minor features (stem tests, backport from 0.4.2.1-alpha):
        - Change "make test-stem" so it only runs the stem tests that use
          tor. This change makes test-stem faster and more reliable. Closes
          ticket 31554.
    
      o Minor bugfixes (build system, backport form 0.4.2.1-alpha):
        - Do not include the deprecated <sys/sysctl.h> on Linux or Windows
          systems. Fixes bug 31673; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (compilation, backport from 0.4.2.1-alpha):
        - Add more stub functions to fix compilation on Android with link-
          time optimization when --disable-module-dirauth is used.
          Previously, these compilation settings would make the compiler
          look for functions that didn't exist. Fixes bug 31552; bugfix
          on 0.4.1.1-alpha.
        - Suppress spurious float-conversion warnings from GCC when calling
          floating-point classifier functions on FreeBSD. Fixes part of bug
          31687; bugfix on 0.3.1.5-alpha.
    
      o Minor bugfixes (controller protocol):
        - Fix the MAPADDRESS controller command to accept one or more
          arguments. Previously, it required two or more arguments, and ignored
          the first. Fixes bug 31772; bugfix on 0.4.1.1-alpha.
    
      o Minor bugfixes (FreeBSD, PF-based proxy, IPv6, backport from 0.4.2.1-alpha):
        - When extracting an IPv6 address from a PF-based proxy, verify that
          we are actually configured to receive an IPv6 address, and log an
          internal error if not. Fixes part of bug 31687; bugfix
          on 0.2.3.4-alpha.
    
      o Minor bugfixes (guards, backport from 0.4.2.1-alpha):
        - When tor is missing descriptors for some primary entry guards,
          make the log message less alarming. It's normal for descriptors to
          expire, as long as tor fetches new ones soon after. Fixes bug
          31657; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.4.2.1-alpha):
        - Change log level of message "Hash of session info was not as
          expected" to LOG_PROTOCOL_WARN. Fixes bug 12399; bugfix
          on 0.1.1.10-alpha.
    
      o Minor bugfixes (rust, backport from 0.4.2.1-alpha):
        - Correctly exclude a redundant rust build job in Travis. Fixes bug
          31463; bugfix on 0.3.5.4-alpha.
    
      o Minor bugfixes (v2 single onion services, backport from 0.4.2.1-alpha):
        - Always retry v2 single onion service intro and rend circuits with
          a 3-hop path. Previously, v2 single onion services used a 3-hop
          path when rendezvous circuits were retried after a remote or
          delayed failure, but a 1-hop path for immediate retries. Fixes bug
          23818; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (v3 single onion services, backport from 0.4.2.1-alpha):
        - Always retry v3 single onion service intro and rend circuits with
          a 3-hop path. Previously, v3 single onion services used a 3-hop
          path when rend circuits were retried after a remote or delayed
          failure, but a 1-hop path for immediate retries. Fixes bug 23818;
          bugfix on 0.3.2.1-alpha.
        - Make v3 single onion services fall back to a 3-hop intro, when all
          intro points are unreachable via a 1-hop path. Previously, v3
          single onion services failed when all intro nodes were unreachable
          via a 1-hop path. Fixes bug 23507; bugfix on 0.3.2.1-alpha.
    
      o Documentation (backport from 0.4.2.1-alpha):
        - Use RFC 2397 data URL scheme to embed an image into tor-exit-
          notice.html so that operators no longer have to host it
          themselves. Closes ticket 31089.
    
    
    Changes in version 0.4.1.5 - 2019-08-20
      This is the first stable release in the 0.4.1.x series. This series
      adds experimental circuit-level padding, authenticated SENDME cells to
      defend against certain attacks, and several performance improvements
      to save on CPU consumption. It fixes bugs in bootstrapping and v3
      onion services. It also includes numerous smaller features and
      bugfixes on earlier versions.
    
      Per our support policy, we will support the 0.4.1.x series for nine
      months, or until three months after the release of a stable 0.4.2.x:
      whichever is longer. If you need longer-term support, please stick
      with 0.3.5.x, which will we plan to support until Feb 2022.
    
      Below are the changes since 0.4.0.5. For a list of only the changes
      since 0.4.1.4-rc, see the ChangeLog file.
    
      o Directory authority changes:
        - The directory authority "dizum" has a new IP address. Closes
          ticket 31406.
    
      o Major features (circuit padding):
        - Onion service clients now add padding cells at the start of their
          INTRODUCE and RENDEZVOUS circuits, to make those circuits' traffic
          look more like general purpose Exit traffic. The overhead for this
          is 2 extra cells in each direction for RENDEZVOUS circuits, and 1
          extra upstream cell and 10 downstream cells for INTRODUCE
          circuits. This feature is only enabled when also supported by the
          circuit's middle node. (Clients may specify fixed middle nodes
          with the MiddleNodes option, and may force-disable this feature
          with the CircuitPadding option.) Closes ticket 28634.
    
      o Major features (code organization):
        - Tor now includes a generic publish-subscribe message-passing
          subsystem that we can use to organize intermodule dependencies. We
          hope to use this to reduce dependencies between modules that don't
          need to be related, and to generally simplify our codebase. Closes
          ticket 28226.
    
      o Major features (controller protocol):
        - Controller commands are now parsed using a generalized parsing
          subsystem. Previously, each controller command was responsible for
          parsing its own input, which led to strange inconsistencies.
          Closes ticket 30091.
    
      o Major features (flow control):
        - Implement authenticated SENDMEs as detailed in proposal 289. A
          SENDME cell now includes the digest of the traffic that it
          acknowledges, so that once an end point receives the SENDME, it
          can confirm the other side's knowledge of the previous cells that
          were sent, and prevent certain types of denial-of-service attacks.
          This behavior is controlled by two new consensus parameters: see
          the proposal for more details. Fixes ticket 26288.
    
      o Major features (performance):
        - Our node selection algorithm now excludes nodes in linear time.
          Previously, the algorithm was quadratic, which could slow down
          heavily used onion services. Closes ticket 30307.
    
      o Major features (performance, RNG):
        - Tor now constructs a fast secure pseudorandom number generator for
          each thread, to use when performance is critical. This PRNG is
          based on AES-CTR, using a buffering construction similar to
          libottery and the (newer) OpenBSD arc4random() code. It
          outperforms OpenSSL 1.1.1a's CSPRNG by roughly a factor of 100 for
          small outputs. Although we believe it to be cryptographically
          strong, we are only using it when necessary for performance.
          Implements tickets 29023 and 29536.
    
      o Major bugfixes (bridges):
        - Consider our directory information to have changed when our list
          of bridges changes. Previously, Tor would not re-compute the
          status of its directory information when bridges changed, and
          therefore would not realize that it was no longer able to build
          circuits. Fixes part of bug 29875.
        - Do not count previously configured working bridges towards our
          total of working bridges. Previously, when Tor's list of bridges
          changed, it would think that the old bridges were still usable,
          and delay fetching router descriptors for the new ones. Fixes part
          of bug 29875; bugfix on 0.3.0.1-alpha.
    
      o Major bugfixes (circuit build, guard):
        - On relays, properly check that a padding machine is absent before
          logging a warning about it being absent. Fixes bug 30649; bugfix
          on 0.4.0.1-alpha.
        - When considering upgrading circuits from "waiting for guard" to
          "open", always ignore circuits that are marked for close. Otherwise,
          we can end up in the situation where a subsystem is notified that
          a closing circuit has just opened, leading to undesirable
          behavior. Fixes bug 30871; bugfix on 0.3.0.1-alpha.
    
      o Major bugfixes (onion service reachability):
        - Properly clean up the introduction point map when circuits change
          purpose from onion service circuits to pathbias, measurement, or
          other circuit types. This should fix some service-side instances
          of introduction point failure. Fixes bug 29034; bugfix
          on 0.3.2.1-alpha.
    
      o Major bugfixes (onion service v3):
        - Fix an unreachable bug in which an introduction point could try to
          send an INTRODUCE_ACK with a status code that Trunnel would refuse
          to encode, leading the relay to assert(). We've consolidated the
          ABI values into Trunnel now. Fixes bug 30454; bugfix
          on 0.3.0.1-alpha.
        - Clients can now handle unknown status codes from INTRODUCE_ACK
          cells. (The NACK behavior will stay the same.) This will allow us
          to extend status codes in the future without breaking the normal
          client behavior. Fixes another part of bug 30454; bugfix
          on 0.3.0.1-alpha.
    
      o Minor features (authenticated SENDME):
        - Ensure that there is enough randomness on every circuit to prevent
          an attacker from successfully predicting the hashes they will need
          to include in authenticated SENDME cells. At a random interval, if
          we have not sent randomness already, we now leave some extra space
          at the end of a cell that we can fill with random bytes. Closes
          ticket 26846.
    
      o Minor features (circuit padding logging):
        - Demote noisy client-side warn logs about circuit padding to protocol
          warnings. Add additional log messages and circuit ID fields to help
          with bug 30992 and any other future issues.
    
      o Minor features (circuit padding):
        - We now use a fast PRNG when scheduling circuit padding. Part of
          ticket 28636.
        - Allow the padding machine designer to pick the edges of their
          histogram instead of trying to compute them automatically using an
          exponential formula. Resolves some undefined behavior in the case
          of small histograms and allows greater flexibility on machine
          design. Closes ticket 29298; bugfix on 0.4.0.1-alpha.
        - Allow circuit padding machines to hold a circuit open until they
          are done padding it. Closes ticket 28780.
    
      o Minor features (compile-time modules):
        - Add a "--list-modules" command to print a list of which compile-
          time modules are enabled. Closes ticket 30452.
    
      o Minor features (continuous integration):
        - Our Travis configuration now uses Chutney to run some network
          integration tests automatically. Closes ticket 29280.
        - When running coverage builds on Travis, we now set
          TOR_TEST_RNG_SEED, to avoid RNG-based coverage differences. Part
          of ticket 28878.
        - Remove sudo configuration lines from .travis.yml as they are no
          longer needed with current Travis build environment. Resolves
          issue 30213.
        - In Travis, show stem's tor log after failure. Closes ticket 30234.
    
      o Minor features (controller):
        - Add onion service version 3 support to the HSFETCH command.
          Previously, only version 2 onion services were supported. Closes
          ticket 25417. Patch by Neel Chauhan.
    
      o Minor features (debugging):
        - Introduce tor_assertf() and tor_assertf_nonfatal() to enable
          logging of additional information during assert failure. Now we
          can use format strings to include information for trouble
          shooting. Resolves ticket 29662.
    
      o Minor features (defense in depth):
        - In smartlist_remove_keeporder(), set unused pointers to NULL, in
          case a bug causes them to be used later. Closes ticket 30176.
          Patch from Tobias Stoeckmann.
        - Tor now uses a cryptographically strong PRNG even for decisions
          that we do not believe are security-sensitive. Previously, for
          performance reasons, we had used a trivially predictable linear
          congruential generator algorithm for certain load-balancing and
          statistical sampling decisions. Now we use our fast RNG in those
          cases. Closes ticket 29542.
    
      o Minor features (developer tools):
        - Tor's "practracker" test script now checks for files and functions
          that seem too long and complicated. Existing overlong functions
          and files are accepted for now, but should eventually be
          refactored. Closes ticket 29221.
        - Add some scripts used for git maintenance to scripts/git. Closes
          ticket 29391.
        - Call practracker from pre-push and pre-commit git hooks to let
          developers know if they made any code style violations. Closes
          ticket 30051.
        - Add a script to check that each header has a well-formed and
          unique guard macro. Closes ticket 29756.
    
      o Minor features (fallback directory list):
        - Replace the 157 fallbacks originally introduced in Tor 0.3.5.6-rc
          in December 2018 (of which ~122 were still functional), with a
          list of 148 fallbacks (70 new, 78 existing, 79 removed) generated
          in June 2019. Closes ticket 28795.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the June 10 2019 Maxmind GeoLite2
          Country database. Closes ticket 30852.
        - Update geoip and geoip6 to the May 13 2019 Maxmind GeoLite2
          Country database. Closes ticket 30522.
    
      o Minor features (HTTP tunnel):
        - Return an informative web page when the HTTPTunnelPort is used as
          an HTTP proxy. Closes ticket 27821, patch by "eighthave".
    
      o Minor features (IPv6, v3 onion services):
        - Make v3 onion services put IPv6 addresses in service descriptors.
          Before this change, service descriptors only contained IPv4
          addresses. Implements 26992.
    
      o Minor features (logging):
        - Give a more useful assertion failure message if we think we have
          minherit() but we fail to make a region non-inheritable. Give a
          compile-time warning if our support for minherit() is incomplete.
          Closes ticket 30686.
    
      o Minor features (maintenance):
        - Add a new "make autostyle" target that developers can use to apply
          all automatic Tor style and consistency conversions to the
          codebase. Closes ticket 30539.
    
      o Minor features (modularity):
        - The "--disable-module-dirauth" compile-time option now disables
          even more dirauth-only code. Closes ticket 30345.
    
      o Minor features (performance):
        - Use OpenSSL's implementations of SHA3 when available (in OpenSSL
          1.1.1 and later), since they tend to be faster than tiny-keccak.
          Closes ticket 28837.
    
      o Minor features (testing):
        - The circuitpadding tests now use a reproducible RNG implementation,
          so that if a test fails, we can learn why. Part of ticket 28878.
        - Tor's tests now support an environment variable, TOR_TEST_RNG_SEED,
          to set the RNG seed for tests that use a reproducible RNG. Part of
          ticket 28878.
        - When running tests in coverage mode, take additional care to make
          our coverage deterministic, so that we can accurately track
          changes in code coverage. Closes ticket 30519.
        - Tor's unit test code now contains helper functions to replace the
          PRNG with a deterministic or reproducible version for testing.
          Previously, various tests implemented this in various ways.
          Implements ticket 29732.
        - We now have a script, cov-test-determinism.sh, to identify places
          where our unit test coverage has become nondeterministic. Closes
          ticket 29436.
        - Check that representative subsets of values of `int` and `unsigned
          int` can be represented by `void *`. Resolves issue 29537.
    
      o Minor bugfixes (bridge authority):
        - Bridge authorities now set bridges as running or non-running when
          about to dump their status to a file. Previously, they set bridges
          as running in response to a GETINFO command, but those shouldn't
          modify data structures. Fixes bug 24490; bugfix on 0.2.0.13-alpha.
          Patch by Neel Chauhan.
    
      o Minor bugfixes (channel padding statistics):
        - Channel padding write totals and padding-enabled totals are now
          counted properly in relay extrainfo descriptors. Fixes bug 29231;
          bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (circuit isolation):
        - Fix a logic error that prevented the SessionGroup sub-option from
          being accepted. Fixes bug 22619; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (circuit padding):
        - Add a "CircuitPadding" torrc option to disable circuit padding.
          Fixes bug 28693; bugfix on 0.4.0.1-alpha.
        - Allow circuit padding machines to specify that they do not
          contribute much overhead, and provide consensus flags and torrc
          options to force clients to only use these low overhead machines.
          Fixes bug 29203; bugfix on 0.4.0.1-alpha.
        - Provide a consensus parameter to fully disable circuit padding, to
          be used in emergency network overload situations. Fixes bug 30173;
          bugfix on 0.4.0.1-alpha.
        - The circuit padding subsystem will no longer schedule padding if
          dormant mode is enabled. Fixes bug 28636; bugfix on 0.4.0.1-alpha.
        - Inspect a circuit-level cell queue before sending padding, to
          avoid sending padding while too much data is already queued. Fixes
          bug 29204; bugfix on 0.4.0.1-alpha.
        - Avoid calling monotime_absolute_usec() in circuit padding machines
          that do not use token removal or circuit RTT estimation. Fixes bug
          29085; bugfix on 0.4.0.1-alpha.
    
      o Minor bugfixes (clock skew detection):
        - Don't believe clock skew results from NETINFO cells that appear to
          arrive before we sent the VERSIONS cells they are responding to.
          Previously, we would accept them up to 3 minutes "in the past".
          Fixes bug 31343; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (compatibility, standards compliance):
        - Fix a bug that would invoke undefined behavior on certain
          operating systems when trying to asprintf() a string exactly
          INT_MAX bytes long. We don't believe this is exploitable, but it's
          better to fix it anyway. Fixes bug 31001; bugfix on 0.2.2.11-alpha.
          Found and fixed by Tobias Stoeckmann.
    
      o Minor bugfixes (compilation warning):
        - Fix a compilation warning on Windows about casting a function
          pointer for GetTickCount64(). Fixes bug 31374; bugfix on
          0.2.9.1-alpha.
    
      o Minor bugfixes (compilation):
        - Avoid using labs() on time_t, which can cause compilation warnings
          on 64-bit Windows builds.  Fixes bug 31343; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (compilation, unusual configurations):
        - Avoid failures when building with the ALL_BUGS_ARE_FATAL option
          due to missing declarations of abort(), and prevent other such
          failures in the future. Fixes bug 30189; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (configuration, proxies):
        - Fix a bug that prevented us from supporting SOCKS5 proxies that
          want authentication along with configured (but unused!)
          ClientTransportPlugins. Fixes bug 29670; bugfix on 0.2.6.1-alpha.
    
      o Minor bugfixes (continuous integration):
        - Allow the test-stem job to fail in Travis, because it sometimes
          hangs. Fixes bug 30744; bugfix on 0.3.5.4-alpha.
        - Skip test_rebind on macOS in Travis, because it is unreliable on
          macOS on Travis. Fixes bug 30713; bugfix on 0.3.5.1-alpha.
        - Skip test_rebind when the TOR_SKIP_TEST_REBIND environment
          variable is set. Fixes bug 30713; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (controller protocol):
        - Teach the controller parser to distinguish an object preceded by
          an argument list from one without. Previously, it couldn't
          distinguish an argument list from the first line of a multiline
          object. Fixes bug 29984; bugfix on 0.2.3.8-alpha.
    
      o Minor bugfixes (crash on exit):
        - Avoid a set of possible code paths that could try to use freed
          memory in routerlist_free() while Tor was exiting. Fixes bug
          31003; bugfix on 0.1.2.2-alpha.
    
      o Minor bugfixes (developer tooling):
        - Fix pre-push hook to allow fixup and squash commits when pushing
          to non-upstream git remote. Fixes bug 30286; bugfix
          on 0.4.0.1-alpha.
    
      o Minor bugfixes (directory authorities):
        - Stop crashing after parsing an unknown descriptor purpose
          annotation. We think this bug can only be triggered by modifying a
          local file. Fixes bug 30781; bugfix on 0.2.0.8-alpha.
        - Move the "bandwidth-file-headers" line in directory authority
          votes so that it conforms to dir-spec.txt. Fixes bug 30316; bugfix
          on 0.3.5.1-alpha.
        - Directory authorities with IPv6 support now always mark themselves
          as reachable via IPv6. Fixes bug 24338; bugfix on 0.2.4.1-alpha.
          Patch by Neel Chauhan.
    
      o Minor bugfixes (documentation):
        - Improve the documentation for using MapAddress with ".exit". Fixes
          bug 30109; bugfix on 0.1.0.1-rc.
        - Improve the monotonic time module and function documentation to
          explain what "monotonic" actually means, and document some results
          that have surprised people. Fixes bug 29640; bugfix
          on 0.2.9.1-alpha.
        - Use proper formatting when providing an example on quoting options
          that contain whitespace. Fixes bug 29635; bugfix on 0.2.3.18-rc.
    
      o Minor bugfixes (logging):
        - Do not log a warning when running with an OpenSSL version other
          than the one Tor was compiled with, if the two versions should be
          compatible. Previously, we would warn whenever the version was
          different. Fixes bug 30190; bugfix on 0.2.4.2-alpha.
        - Warn operators when the MyFamily option is set but ContactInfo is
          missing, as the latter should be set too. Fixes bug 25110; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (memory leaks):
        - Avoid a minor memory leak that could occur on relays when failing
          to create a "keys" directory. Fixes bug 30148; bugfix
          on 0.3.3.1-alpha.
        - Fix a trivial memory leak when parsing an invalid value from a
          download schedule in the configuration. Fixes bug 30894; bugfix
          on 0.3.4.1-alpha.
    
      o Minor bugfixes (NetBSD):
        - Fix usage of minherit() on NetBSD and other platforms that define
          MAP_INHERIT_{ZERO,NONE} instead of INHERIT_{ZERO,NONE}. Fixes bug
          30614; bugfix on 0.4.0.2-alpha. Patch from Taylor Campbell.
    
      o Minor bugfixes (onion services):
        - Avoid a GCC 9.1.1 warning (and possible crash depending on libc
          implementation) when failing to load an onion service client
          authorization file. Fixes bug 30475; bugfix on 0.3.5.1-alpha.
        - When refusing to launch a controller's HSFETCH request because of
          rate-limiting, respond to the controller with a new response,
          "QUERY_RATE_LIMITED". Previously, we would log QUERY_NO_HSDIR for
          this case. Fixes bug 28269; bugfix on 0.3.1.1-alpha. Patch by
          Neel Chauhan.
        - When relaunching a circuit to a rendezvous service, mark the
          circuit as needing high-uptime routers as appropriate. Fixes bug
          17357; bugfix on 0.1.0.1-rc. Patch by Neel Chauhan.
        - Stop ignoring IPv6 link specifiers sent to v3 onion services.
          (IPv6 support for v3 onion services is still incomplete: see
          ticket 23493 for details.) Fixes bug 23588; bugfix on
          0.3.2.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (onion services, performance):
        - When building circuits to onion services, call tor_addr_parse()
          less often. Previously, we called tor_addr_parse() in
          circuit_is_acceptable() even if its output wasn't used. This
          change should improve performance when building circuits. Fixes
          bug 22210; bugfix on 0.2.8.12. Patch by Neel Chauhan.
    
      o Minor bugfixes (out-of-memory handler):
        - When purging the DNS cache because of an out-of-memory condition,
          try purging just the older entries at first. Previously, we would
          always purge the whole thing. Fixes bug 29617; bugfix
          on 0.3.5.1-alpha.
    
      o Minor bugfixes (performance):
        - When checking whether a node is a bridge, use a fast check to make
          sure that its identity is set. Previously, we used a constant-time
          check, which is not necessary in this case. Fixes bug 30308;
          bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (pluggable transports):
        - Tor now sets TOR_PT_EXIT_ON_STDIN_CLOSE=1 for client transports as
          well as servers. Fixes bug 25614; bugfix on 0.2.7.1-alpha.
    
      o Minor bugfixes (portability):
        - Avoid crashing in our tor_vasprintf() implementation on systems
          that define neither vasprintf() nor _vscprintf(). (This bug has
          been here long enough that we question whether people are running
          Tor on such systems, but we're applying the fix out of caution.)
          Fixes bug 30561; bugfix on 0.2.8.2-alpha. Found and fixed by
          Tobias Stoeckmann.
    
      o Minor bugfixes (probability distributions):
        - Refactor and improve parts of the probability distribution code
          that made Coverity complain. Fixes bug 29805; bugfix
          on 0.4.0.1-alpha.
    
      o Minor bugfixes (python):
        - Stop assuming that /usr/bin/python3 exists. For scripts that work
          with python2, use /usr/bin/python. Otherwise, use /usr/bin/env
          python3. Fixes bug 29913; bugfix on 0.2.5.3-alpha.
    
      o Minor bugfixes (relay):
        - When running as a relay, if IPv6Exit is set to 1 while ExitRelay
          is auto, act as if ExitRelay is 1. Previously, we would ignore
          IPv6Exit if ExitRelay was 0 or auto. Fixes bug 29613; bugfix on
          0.3.5.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (static analysis):
        - Fix several spurious Coverity warnings about the unit tests, to
          lower our chances of missing real warnings in the future. Fixes
          bug 30150; bugfix on 0.3.5.1-alpha and various other Tor versions.
    
      o Minor bugfixes (stats):
        - When ExtraInfoStatistics is 0, stop including bandwidth usage
          statistics, GeoIPFile hashes, ServerTransportPlugin lines, and
          bridge statistics by country in extra-info documents. Fixes bug
          29018; bugfix on 0.2.4.1-alpha.
    
      o Minor bugfixes (testing):
        - Call setrlimit() to disable core dumps in test_bt_cl.c. Previously
          we used `ulimit -c` in test_bt.sh, which violates POSIX shell
          compatibility. Fixes bug 29061; bugfix on 0.3.5.1-alpha.
        - Fix some incorrect code in the v3 onion service unit tests. Fixes
          bug 29243; bugfix on 0.3.2.1-alpha.
        - In the "routerkeys/*" tests, check the return values of mkdir()
          for possible failures. Fixes bug 29939; bugfix on 0.2.7.2-alpha.
          Found by Coverity as CID 1444254.
        - Split test_utils_general() into several smaller test functions.
          This makes it easier to perform resource deallocation on assert
          failure, and fixes Coverity warnings CID 1444117 and CID 1444118.
          Fixes bug 29823; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (tor-resolve):
        - Fix a memory leak in tor-resolve that could happen if Tor gave it
          a malformed SOCKS response. (Memory leaks in tor-resolve don't
          actually matter, but it's good to fix them anyway.) Fixes bug
          30151; bugfix on 0.4.0.1-alpha.
    
      o Code simplification and refactoring:
        - Abstract out the low-level formatting of replies on the control
          port. Implements ticket 30007.
        - Add several assertions in an attempt to fix some Coverity
          warnings. Closes ticket 30149.
        - Introduce a connection_dir_buf_add() helper function that checks
          for compress_state of dir_connection_t and automatically writes a
          string to directory connection with or without compression.
          Resolves issue 28816.
        - Make the base32_decode() API return the number of bytes written,
          for consistency with base64_decode(). Closes ticket 28913.
        - Move most relay-only periodic events out of mainloop.c into the
          relay subsystem. Closes ticket 30414.
        - Refactor and encapsulate parts of the codebase that manipulate
          crypt_path_t objects. Resolves issue 30236.
        - Refactor several places in our code that Coverity incorrectly
          believed might have memory leaks. Closes ticket 30147.
        - Remove redundant return values in crypto_format, and the
          associated return value checks elsewhere in the code. Make the
          implementations in crypto_format consistent, and remove redundant
          code. Resolves ticket 29660.
        - Rename tor_mem_is_zero() to fast_mem_is_zero(), to emphasize that
          it is not a constant-time function. Closes ticket 30309.
        - Replace hs_desc_link_specifier_t with link_specifier_t, and remove
          all hs_desc_link_specifier_t-specific code. Fixes bug 22781;
          bugfix on 0.3.2.1-alpha.
        - Simplify v3 onion service link specifier handling code. Fixes bug
          23576; bugfix on 0.3.2.1-alpha.
        - Split crypto_digest.c into NSS code, OpenSSL code, and shared
          code. Resolves ticket 29108.
        - Split control.c into several submodules, in preparation for
          distributing its current responsibilities throughout the codebase.
          Closes ticket 29894.
        - Start to move responsibility for knowing about periodic events to
          the appropriate subsystems, so that the mainloop doesn't need to
          know all the periodic events in the rest of the codebase.
          Implements tickets 30293 and 30294.
    
      o Documentation:
        - Mention URLs for Travis/Appveyor/Jenkins in ReleasingTor.md.
          Closes ticket 30630.
        - Document how to find git commits and tags for bug fixes in
          CodingStandards.md. Update some file documentation. Closes
          ticket 30261.
    
      o Removed features:
        - Remove the linux-tor-prio.sh script from contrib/operator-tools
          directory. Resolves issue 29434.
        - Remove the obsolete OpenSUSE initscript. Resolves issue 30076.
        - Remove the obsolete script at contrib/dist/tor.sh.in. Resolves
          issue 30075.
    
      o Testing:
        - Specify torrc paths (with empty files) when launching tor in
          integration tests; refrain from reading user and system torrcs.
          Resolves issue 29702.
    
      o Code simplification and refactoring (shell scripts):
        - Clean up many of our shell scripts to fix shellcheck warnings.
          These include autogen.sh (ticket 26069), test_keygen.sh (ticket
          29062), test_switch_id.sh (ticket 29065), test_rebind.sh (ticket
          29063), src/test/fuzz/minimize.sh (ticket 30079), test_rust.sh
          (ticket 29064), torify (ticket 29070), asciidoc-helper.sh (29926),
          fuzz_multi.sh (30077), fuzz_static_testcases.sh (ticket 29059),
          nagios-check-tor-authority-cert (ticket 29071),
          src/test/fuzz/fixup_filenames.sh (ticket 30078), test-network.sh
          (ticket 29060), test_key_expiration.sh (ticket 30002),
          zero_length_keys.sh (ticket 29068), and test_workqueue_*.sh
          (ticket 29067).
    
      o Testing (chutney):
        - In "make test-network-all", test IPv6-only v3 single onion
          services, using the chutney network single-onion-v23-ipv6-md.
          Closes ticket 27251.
    
      o Testing (continuous integration):
        - In Travis, make stem log a controller trace to the console, and tail
          stem's tor log after failure. Closes ticket 30591.
        - In Travis, only run the stem tests that use a tor binary.
          Closes ticket 30694.
    
    
    Changes in version 0.4.0.5 - 2019-05-02
      This is the first stable release in the 0.4.0.x series. It contains
      improvements for power management and bootstrap reporting, as well as
      preliminary backend support for circuit padding to prevent some kinds
      of traffic analysis. It also continues our work in refactoring Tor for
      long-term maintainability.
    
      Per our support policy, we will support the 0.4.0.x series for nine
      months, or until three months after the release of a stable 0.4.1.x:
      whichever is longer. If you need longer-term support, please stick
      with 0.3.5.x, which will we plan to support until Feb 2022.
    
      Below are the changes since 0.3.5.7. For a complete list of changes
      since 0.4.0.4-rc, see the ChangeLog file.
    
      o Major features (battery management, client, dormant mode):
        - When Tor is running as a client, and it is unused for a long time,
          it can now enter a "dormant" state. When Tor is dormant, it avoids
          network and CPU activity until it is reawoken either by a user
          request or by a controller command. For more information, see the
          configuration options starting with "Dormant". Implements tickets
          2149 and 28335.
        - The client's memory of whether it is "dormant", and how long it
          has spent idle, persists across invocations. Implements
          ticket 28624.
        - There is a DormantOnFirstStartup option that integrators can use
          if they expect that in many cases, Tor will be installed but
          not used.
    
      o Major features (bootstrap reporting):
        - When reporting bootstrap progress, report the first connection
          uniformly, regardless of whether it's a connection for building
          application circuits. This allows finer-grained reporting of early
          progress than previously possible, with the improvements of ticket
          27169. Closes tickets 27167 and 27103. Addresses ticket 27308.
        - When reporting bootstrap progress, treat connecting to a proxy or
          pluggable transport as separate from having successfully used that
          proxy or pluggable transport to connect to a relay. Closes tickets
          27100 and 28884.
    
      o Major features (circuit padding):
        - Implement preliminary support for the circuit padding portion of
          Proposal 254. The implementation supports Adaptive Padding (aka
          WTF-PAD) state machines for use between experimental clients and
          relays. Support is also provided for APE-style state machines that
          use probability distributions instead of histograms to specify
          inter-packet delay. At the moment, Tor does not provide any
          padding state machines that are used in normal operation: for now,
          this feature exists solely for experimentation. Closes
          ticket 28142.
    
      o Major features (refactoring):
        - Tor now uses an explicit list of its own subsystems when
          initializing and shutting down. Previously, these systems were
          managed implicitly in various places throughout the codebase.
          (There may still be some subsystems using the old system.) Closes
          ticket 28330.
    
      o Major bugfixes (cell scheduler, KIST, security):
        - Make KIST consider the outbuf length when computing what it can
          put in the outbuf. Previously, KIST acted as though the outbuf
          were empty, which could lead to the outbuf becoming too full. It
          is possible that an attacker could exploit this bug to cause a Tor
          client or relay to run out of memory and crash. Fixes bug 29168;
          bugfix on 0.3.2.1-alpha. This issue is also being tracked as
          TROVE-2019-001 and CVE-2019-8955.
    
      o Major bugfixes (networking):
        - Gracefully handle empty username/password fields in SOCKS5
          username/password auth message and allow SOCKS5 handshake to
          continue. Previously, we had rejected these handshakes, breaking
          certain applications. Fixes bug 29175; bugfix on 0.3.5.1-alpha.
    
      o Major bugfixes (NSS, relay):
        - When running with NSS, disable TLS 1.2 ciphersuites that use
          SHA384 for their PRF. Due to an NSS bug, the TLS key exporters for
          these ciphersuites don't work -- which caused relays to fail to
          handshake with one another when these ciphersuites were enabled.
          Fixes bug 29241; bugfix on 0.3.5.1-alpha.
    
      o Minor features (address selection):
        - Treat the subnet 100.64.0.0/10 as public for some purposes;
          private for others. This subnet is the RFC 6598 (Carrier Grade
          NAT) IP range, and is deployed by many ISPs as an alternative to
          RFC 1918 that does not break existing internal networks. Tor now
          blocks SOCKS and control ports on these addresses and warns users
          if client ports or ExtORPorts are listening on a RFC 6598 address.
          Closes ticket 28525. Patch by Neel Chauhan.
    
      o Minor features (bandwidth authority):
        - Make bandwidth authorities ignore relays that are reported in the
          bandwidth file with the flag "vote=0". This change allows us to
          report unmeasured relays for diagnostic reasons without including
          their bandwidth in the bandwidth authorities' vote. Closes
          ticket 29806.
        - When a directory authority is using a bandwidth file to obtain the
          bandwidth values that will be included in the next vote, serve
          this bandwidth file at /tor/status-vote/next/bandwidth. Closes
          ticket 21377.
    
      o Minor features (bootstrap reporting):
        - When reporting bootstrap progress, stop distinguishing between
          situations where only internal paths are available and situations
          where external paths are available. Previously, Tor would often
          erroneously report that it had only internal paths. Closes
          ticket 27402.
    
      o Minor features (compilation):
        - Compile correctly when OpenSSL is built with engine support
          disabled, or with deprecated APIs disabled. Closes ticket 29026.
          Patches from "Mangix".
    
      o Minor features (continuous integration):
        - On Travis Rust builds, cleanup Rust registry and refrain from
          caching the "target/" directory to speed up builds. Resolves
          issue 29962.
        - Log Python version during each Travis CI job. Resolves
          issue 28551.
        - In Travis, tell timelimit to use stem's backtrace signals, and
          launch python directly from timelimit, so python receives the
          signals from timelimit, rather than make. Closes ticket 30117.
    
      o Minor features (controller):
        - Add a DROPOWNERSHIP command to undo the effects of TAKEOWNERSHIP.
          Implements ticket 28843.
    
      o Minor features (developer tooling):
        - Check that bugfix versions in changes files look like Tor versions
          from the versions spec. Warn when bugfixes claim to be on a future
          release. Closes ticket 27761.
        - Provide a git pre-commit hook that disallows committing if we have
          any failures in our code and changelog formatting checks. It is
          now available in scripts/maint/pre-commit.git-hook. Implements
          feature 28976.
        - Provide a git hook script to prevent "fixup!" and "squash!"
          commits from ending up in the master branch, as scripts/main/pre-
          push.git-hook. Closes ticket 27993.
    
      o Minor features (diagnostic):
        - Add more diagnostic log messages in an attempt to solve the issue
          of NUL bytes appearing in a microdescriptor cache. Related to
          ticket 28223.
    
      o Minor features (directory authority):
        - When a directory authority is using a bandwidth file to obtain
          bandwidth values, include the digest of that file in the vote.
          Closes ticket 26698.
        - Directory authorities support a new consensus algorithm, under
          which the family lines in microdescriptors are encoded in a
          canonical form. This change makes family lines more compressible
          in transit, and on the client. Closes ticket 28266; implements
          proposal 298.
    
      o Minor features (directory authority, relay):
        - Authorities now vote on a "StaleDesc" flag to indicate that a
          relay's descriptor is so old that the relay should upload again
          soon. Relays treat this flag as a signal to upload a new
          descriptor. This flag will eventually let us remove the
          'published' date from routerstatus entries, and make our consensus
          diffs much smaller. Closes ticket 26770; implements proposal 293.
    
      o Minor features (dormant mode):
        - Add a DormantCanceledByStartup option to tell Tor that it should
          treat a startup event as cancelling any previous dormant state.
          Integrators should use this option with caution: it should only be
          used if Tor is being started because of something that the user
          did, and not if Tor is being automatically started in the
          background. Closes ticket 29357.
    
      o Minor features (fallback directory mirrors):
        - Update the fallback whitelist based on operator opt-ins and opt-
          outs. Closes ticket 24805, patch by Phoul.
    
      o Minor features (FreeBSD):
        - On FreeBSD-based systems, warn relay operators if the
          "net.inet.ip.random_id" sysctl (IP ID randomization) is disabled.
          Closes ticket 28518.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the April 2 2019 Maxmind GeoLite2
          Country database. Closes ticket 29992.
    
      o Minor features (HTTP standards compliance):
        - Stop sending the header "Content-type: application/octet-stream"
          along with transparently compressed documents: this confused
          browsers. Closes ticket 28100.
    
      o Minor features (IPv6):
        - We add an option ClientAutoIPv6ORPort, to make clients randomly
          prefer a node's IPv4 or IPv6 ORPort. The random preference is set
          every time a node is loaded from a new consensus or bridge config.
          We expect that this option will enable clients to bootstrap more
          quickly without having to determine whether they support IPv4,
          IPv6, or both. Closes ticket 27490. Patch by Neel Chauhan.
        - When using addrs_in_same_network_family(), avoid choosing circuit
          paths that pass through the same IPv6 subnet more than once.
          Previously, we only checked IPv4 subnets. Closes ticket 24393.
          Patch by Neel Chauhan.
    
      o Minor features (log messages):
        - Improve log message in v3 onion services that could print out
          negative revision counters. Closes ticket 27707. Patch
          by "ffmancera".
    
      o Minor features (memory usage):
        - Save memory by storing microdescriptor family lists with a more
          compact representation. Closes ticket 27359.
        - Tor clients now use mmap() to read consensus files from disk, so
          that they no longer need keep the full text of a consensus in
          memory when parsing it or applying a diff. Closes ticket 27244.
    
      o Minor features (NSS, diagnostic):
        - Try to log an error from NSS (if there is any) and a more useful
          description of our situation if we are using NSS and a call to
          SSL_ExportKeyingMaterial() fails. Diagnostic for ticket 29241.
    
      o Minor features (parsing):
        - Directory authorities now validate that router descriptors and
          ExtraInfo documents are in a valid subset of UTF-8, and reject
          them if they are not. Closes ticket 27367.
    
      o Minor features (performance):
        - Cache the results of summarize_protocol_flags(), so that we don't
          have to parse the same protocol-versions string over and over.
          This should save us a huge number of malloc calls on startup, and
          may reduce memory fragmentation with some allocators. Closes
          ticket 27225.
        - Remove a needless memset() call from get_token_arguments, thereby
          speeding up the tokenization of directory objects by about 20%.
          Closes ticket 28852.
        - Replace parse_short_policy() with a faster implementation, to
          improve microdescriptor parsing time. Closes ticket 28853.
        - Speed up directory parsing a little by avoiding use of the non-
          inlined strcmp_len() function. Closes ticket 28856.
        - Speed up microdescriptor parsing by about 30%, to help improve
          startup time. Closes ticket 28839.
    
      o Minor features (pluggable transports):
        - Add support for emitting STATUS updates to Tor's control port from
          a pluggable transport process. Closes ticket 28846.
        - Add support for logging to Tor's logging subsystem from a
          pluggable transport process. Closes ticket 28180.
    
      o Minor features (process management):
        - Add a new process API for handling child processes. This new API
          allows Tor to have bi-directional communication with child
          processes on both Unix and Windows. Closes ticket 28179.
        - Use the subsystem manager to initialize and shut down the process
          module. Closes ticket 28847.
    
      o Minor features (relay):
        - When listing relay families, list them in canonical form including
          the relay's own identity, and try to give a more useful set of
          warnings. Part of ticket 28266 and proposal 298.
    
      o Minor features (required protocols):
        - Before exiting because of a missing required protocol, Tor will
          now check the publication time of the consensus, and not exit
          unless the consensus is newer than the Tor program's own release
          date. Previously, Tor would not check the consensus publication
          time, and so might exit because of a missing protocol that might
          no longer be required in a current consensus. Implements proposal
          297; closes ticket 27735.
    
      o Minor features (testing):
        - Treat all unexpected ERR and BUG messages as test failures. Closes
          ticket 28668.
        - Allow a HeartbeatPeriod of less than 30 minutes in testing Tor
          networks. Closes ticket 28840. Patch by Rob Jansen.
        - Use the approx_time() function when setting the "Expires" header
          in directory replies, to make them more testable. Needed for
          ticket 30001.
    
      o Minor bugfixes (security):
        - Fix a potential double free bug when reading huge bandwidth files.
          The issue is not exploitable in the current Tor network because
          the vulnerable code is only reached when directory authorities
          read bandwidth files, but bandwidth files come from a trusted
          source (usually the authorities themselves). Furthermore, the
          issue is only exploitable in rare (non-POSIX) 32-bit architectures,
          which are not used by any of the current authorities. Fixes bug
          30040; bugfix on 0.3.5.1-alpha. Bug found and fixed by
          Tobias Stoeckmann.
        - Verify in more places that we are not about to create a buffer
          with more than INT_MAX bytes, to avoid possible OOB access in the
          event of bugs. Fixes bug 30041; bugfix on 0.2.0.16. Found and
          fixed by Tobias Stoeckmann.
    
      o Minor bugfix (continuous integration):
        - Reset coverage state on disk after Travis CI has finished. This
          should prevent future coverage merge errors from causing the test
          suite for the "process" subsystem to fail. The process subsystem
          was introduced in 0.4.0.1-alpha. Fixes bug 29036; bugfix
          on 0.2.9.15.
        - Terminate test-stem if it takes more than 9.5 minutes to run.
          (Travis terminates the job after 10 minutes of no output.)
          Diagnostic for 29437. Fixes bug 30011; bugfix on 0.3.5.4-alpha.
    
      o Minor bugfixes (build, compatibility, rust):
        - Update Cargo.lock file to match the version made by the latest
          version of Rust, so that "make distcheck" will pass again. Fixes
          bug 29244; bugfix on 0.3.3.4-alpha.
    
      o Minor bugfixes (C correctness):
        - Fix an unlikely memory leak in consensus_diff_apply(). Fixes bug
          29824; bugfix on 0.3.1.1-alpha. This is Coverity warning
          CID 1444119.
    
      o Minor bugfixes (client, clock skew):
        - Bootstrap successfully even when Tor's clock is behind the clocks
          on the authorities. Fixes bug 28591; bugfix on 0.2.0.9-alpha.
        - Select guards even if the consensus has expired, as long as the
          consensus is still reasonably live. Fixes bug 24661; bugfix
          on 0.3.0.1-alpha.
    
      o Minor bugfixes (compilation):
        - Silence a compiler warning in test-memwipe.c on OpenBSD. Fixes bug
          29145; bugfix on 0.2.9.3-alpha. Patch from Kris Katterjohn.
        - Compile correctly on OpenBSD; previously, we were missing some
          headers required in order to detect it properly. Fixes bug 28938;
          bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn.
    
      o Minor bugfixes (directory clients):
        - Mark outdated dirservers when Tor only has a reasonably live
          consensus. Fixes bug 28569; bugfix on 0.3.2.5-alpha.
    
      o Minor bugfixes (directory mirrors):
        - Even when a directory mirror's clock is behind the clocks on the
          authorities, we now allow the mirror to serve "future"
          consensuses. Fixes bug 28654; bugfix on 0.3.0.1-alpha.
    
      o Minor bugfixes (DNS):
        - Gracefully handle an empty or absent resolve.conf file by falling
          back to using "localhost" as a DNS server (and hoping it works).
          Previously, we would just stop running as an exit. Fixes bug
          21900; bugfix on 0.2.1.10-alpha.
    
      o Minor bugfixes (documentation):
        - Describe the contents of the v3 onion service client authorization
          files correctly: They hold public keys, not private keys. Fixes
          bug 28979; bugfix on 0.3.5.1-alpha. Spotted by "Felixix".
    
      o Minor bugfixes (guards):
        - In count_acceptable_nodes(), the minimum number is now one bridge
          or guard node, and two non-guard nodes for a circuit. Previously,
          we had added up the sum of all nodes with a descriptor, but that
          could cause us to build failing circuits when we had either too
          many bridges or not enough guard nodes. Fixes bug 25885; bugfix on
          0.2.3.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (IPv6):
        - Fix tor_ersatz_socketpair on IPv6-only systems. Previously, the
          IPv6 socket was bound using an address family of AF_INET instead
          of AF_INET6. Fixes bug 28995; bugfix on 0.3.5.1-alpha. Patch from
          Kris Katterjohn.
    
      o Minor bugfixes (logging):
        - Correct a misleading error message when IPv4Only or IPv6Only is
          used but the resolved address can not be interpreted as an address
          of the specified IP version. Fixes bug 13221; bugfix on
          0.2.3.9-alpha. Patch from Kris Katterjohn.
        - Log the correct port number for listening sockets when "auto" is
          used to let Tor pick the port number. Previously, port 0 was
          logged instead of the actual port number. Fixes bug 29144; bugfix
          on 0.3.5.1-alpha. Patch from Kris Katterjohn.
        - Stop logging a BUG() warning when Tor is waiting for exit
          descriptors. Fixes bug 28656; bugfix on 0.3.5.1-alpha.
        - Avoid logging that we are relaxing a circuit timeout when that
          timeout is fixed. Fixes bug 28698; bugfix on 0.2.4.7-alpha.
        - Log more information at "warning" level when unable to read a
          private key; log more information at "info" level when unable to
          read a public key. We had warnings here before, but they were lost
          during our NSS work. Fixes bug 29042; bugfix on 0.3.5.1-alpha.
        - Rework rep_hist_log_link_protocol_counts() to iterate through all
          link protocol versions when logging incoming/outgoing connection
          counts. Tor no longer skips version 5, and we won't have to
          remember to update this function when new link protocol version is
          developed. Fixes bug 28920; bugfix on 0.2.6.10.
    
      o Minor bugfixes (memory management):
        - Refactor the shared random state's memory management so that it
          actually takes ownership of the shared random value pointers.
          Fixes bug 29706; bugfix on 0.2.9.1-alpha.
        - Stop leaking parts of the shared random state in the shared-random
          unit tests. Fixes bug 29599; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (misc):
        - The amount of total available physical memory is now determined
          using the sysctl identifier HW_PHYSMEM (rather than HW_USERMEM)
          when it is defined and a 64-bit variant is not available. Fixes
          bug 28981; bugfix on 0.2.5.4-alpha. Patch from Kris Katterjohn.
    
      o Minor bugfixes (networking):
        - Introduce additional checks into tor_addr_parse() to reject
          certain incorrect inputs that previously were not detected. Fixes
          bug 23082; bugfix on 0.2.0.10-alpha.
    
      o Minor bugfixes (onion service v3, client):
        - Stop logging a "BUG()" warning and stacktrace when we find a SOCKS
          connection waiting for a descriptor that we actually have in the
          cache. It turns out that this can actually happen, though it is
          rare. Now, tor will recover and retry the descriptor. Fixes bug
          28669; bugfix on 0.3.2.4-alpha.
    
      o Minor bugfixes (onion services):
        - Avoid crashing if ClientOnionAuthDir (incorrectly) contains more
          than one private key for a hidden service. Fixes bug 29040; bugfix
          on 0.3.5.1-alpha.
        - In hs_cache_store_as_client() log an HSDesc we failed to parse at
          "debug" level. Tor used to log it as a warning, which caused very
          long log lines to appear for some users. Fixes bug 29135; bugfix
          on 0.3.2.1-alpha.
        - Stop logging "Tried to establish rendezvous on non-OR circuit..."
          as a warning. Instead, log it as a protocol warning, because there
          is nothing that relay operators can do to fix it. Fixes bug 29029;
          bugfix on 0.2.5.7-rc.
    
      o Minor bugfixes (periodic events):
        - Refrain from calling routerlist_remove_old_routers() from
          check_descriptor_callback(). Instead, create a new hourly periodic
          event. Fixes bug 27929; bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (pluggable transports):
        - Make sure that data is continously read from standard output and
          standard error pipes of a pluggable transport child-process, to
          avoid deadlocking when a pipe's buffer is full. Fixes bug 26360;
          bugfix on 0.2.3.6-alpha.
    
      o Minor bugfixes (rust):
        - Abort on panic in all build profiles, instead of potentially
          unwinding into C code. Fixes bug 27199; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (scheduler):
        - When re-adding channels to the pending list, check the correct
          channel's sched_heap_idx. This issue has had no effect in mainline
          Tor, but could have led to bugs down the road in improved versions
          of our circuit scheduling code. Fixes bug 29508; bugfix
          on 0.3.2.10.
    
      o Minor bugfixes (single onion services):
        - Allow connections to single onion services to remain idle without
          being disconnected. Previously, relays acting as rendezvous points
          for single onion services were mistakenly closing idle rendezvous
          circuits after 60 seconds, thinking that they were unused
          directory-fetching circuits that had served their purpose. Fixes
          bug 29665; bugfix on 0.2.1.26.
    
      o Minor bugfixes (stats):
        - When ExtraInfoStatistics is 0, stop including PaddingStatistics in
          relay and bridge extra-info documents. Fixes bug 29017; bugfix
          on 0.3.1.1-alpha.
    
      o Minor bugfixes (testing):
        - Backport the 0.3.4 src/test/test-network.sh to 0.2.9. We need a
          recent test-network.sh to use new chutney features in CI. Fixes
          bug 29703; bugfix on 0.2.9.1-alpha.
        - Fix a test failure on Windows caused by an unexpected "BUG"
          warning in our tests for tor_gmtime_r(-1). Fixes bug 29922; bugfix
          on 0.2.9.3-alpha.
        - Downgrade some LOG_ERR messages in the address/* tests to
          warnings. The LOG_ERR messages were occurring when we had no
          configured network. We were failing the unit tests, because we
          backported 28668 to 0.3.5.8, but did not backport 29530. Fixes bug
          29530; bugfix on 0.3.5.8.
        - Fix our gcov wrapper script to look for object files at the
          correct locations. Fixes bug 29435; bugfix on 0.3.5.1-alpha.
        - Detect and suppress "bug" warnings from the util/time test on
          Windows. Fixes bug 29161; bugfix on 0.2.9.3-alpha.
        - Do not log an error-level message if we fail to find an IPv6
          network interface from the unit tests. Fixes bug 29160; bugfix
          on 0.2.7.3-rc.
        - Instead of relying on hs_free_all() to clean up all onion service
          objects in test_build_descriptors(), we now deallocate them one by
          one. This lets Coverity know that we are not leaking memory there
          and fixes CID 1442277. Fixes bug 28989; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (TLS protocol):
        - When classifying a client's selection of TLS ciphers, if the
          client ciphers are not yet available, do not cache the result.
          Previously, we had cached the unavailability of the cipher list
          and never looked again, which in turn led us to assume that the
          client only supported the ancient V1 link protocol. This, in turn,
          was causing Stem integration tests to stall in some cases. Fixes
          bug 30021; bugfix on 0.2.4.8-alpha.
    
      o Minor bugfixes (usability):
        - Stop saying "Your Guard ..." in pathbias_measure_{use,close}_rate().
          Some users took this phrasing to mean that the mentioned guard was
          under their control or responsibility, which it is not. Fixes bug
          28895; bugfix on Tor 0.3.0.1-alpha.
    
      o Minor bugfixes (Windows, CI):
        - Skip the Appveyor 32-bit Windows Server 2016 job, and 64-bit
          Windows Server 2012 R2 job. The remaining 2 jobs still provide
          coverage of 64/32-bit, and Windows Server 2016/2012 R2. Also set
          fast_finish, so failed jobs terminate the build immediately. Fixes
          bug 29601; bugfix on 0.3.5.4-alpha.
    
      o Code simplification and refactoring:
        - Introduce a connection_dir_buf_add() helper function that detects
          whether compression is in use, and adds a string accordingly.
          Resolves issue 28816.
        - Refactor handle_get_next_bandwidth() to use
          connection_dir_buf_add(). Implements ticket 29897.
        - Reimplement NETINFO cell parsing and generation to rely on
          trunnel-generated wire format handling code. Closes ticket 27325.
        - Remove unnecessary unsafe code from the Rust macro "cstr!". Closes
          ticket 28077.
        - Rework SOCKS wire format handling to rely on trunnel-generated
          parsing/generation code. Resolves ticket 27620.
        - Split out bootstrap progress reporting from control.c into a
          separate file. Part of ticket 27402.
        - The .may_include files that we use to describe our directory-by-
          directory dependency structure now describe a noncircular
          dependency graph over the directories that they cover. Our
          checkIncludes.py tool now enforces this noncircularity. Closes
          ticket 28362.
    
      o Documentation:
        - Clarify that Tor performs stream isolation among *Port listeners
          by default. Resolves issue 29121.
        - In the manpage entry describing MapAddress torrc setting, use
          example IP addresses from ranges specified for use in documentation
          by RFC 5737. Resolves issue 28623.
        - Mention that you cannot add a new onion service if Tor is already
          running with Sandbox enabled. Closes ticket 28560.
        - Improve ControlPort documentation. Mention that it accepts
          address:port pairs, and can be used multiple times. Closes
          ticket 28805.
        - Document the exact output of "tor --version". Closes ticket 28889.
    
      o Removed features:
        - Remove the old check-tor script. Resolves issue 29072.
        - Stop responding to the 'GETINFO status/version/num-concurring' and
          'GETINFO status/version/num-versioning' control port commands, as
          those were deprecated back in 0.2.0.30. Also stop listing them in
          output of 'GETINFO info/names'. Resolves ticket 28757.
        - The scripts used to generate and maintain the list of fallback
          directories have been extracted into a new "fallback-scripts"
          repository. Closes ticket 27914.
    
      o Testing:
        - Run shellcheck for scripts in the in scripts/ directory. Closes
          ticket 28058.
        - Add unit tests for tokenize_string() and get_next_token()
          functions. Resolves ticket 27625.
    
      o Code simplification and refactoring (onion service v3):
        - Consolidate the authorized client descriptor cookie computation
          code from client and service into one function. Closes
          ticket 27549.
    
      o Code simplification and refactoring (shell scripts):
        - Cleanup scan-build.sh to silence shellcheck warnings. Closes
          ticket 28007.
        - Fix issues that shellcheck found in chutney-git-bisect.sh.
          Resolves ticket 28006.
        - Fix issues that shellcheck found in updateRustDependencies.sh.
          Resolves ticket 28012.
        - Fix shellcheck warnings in cov-diff script. Resolves issue 28009.
        - Fix shellcheck warnings in run_calltool.sh. Resolves ticket 28011.
        - Fix shellcheck warnings in run_trunnel.sh. Resolves issue 28010.
        - Fix shellcheck warnings in scripts/test/coverage. Resolves
          issue 28008.
    
    
    Changes in version 0.3.5.8 - 2019-02-21
      Tor 0.3.5.8 backports several fixes from later releases, including fixes
      for an annoying SOCKS-parsing bug that affected users in earlier 0.3.5.x
      releases.
    
      It also includes a fix for a medium-severity security bug affecting Tor
      0.3.2.1-alpha and later. All Tor instances running an affected release
      should upgrade to 0.3.3.12, 0.3.4.11, 0.3.5.8, or 0.4.0.2-alpha.
    
      o Major bugfixes (cell scheduler, KIST, security):
        - Make KIST consider the outbuf length when computing what it can
          put in the outbuf. Previously, KIST acted as though the outbuf
          were empty, which could lead to the outbuf becoming too full. It
          is possible that an attacker could exploit this bug to cause a Tor
          client or relay to run out of memory and crash. Fixes bug 29168;
          bugfix on 0.3.2.1-alpha. This issue is also being tracked as
          TROVE-2019-001 and CVE-2019-8955.
    
      o Major bugfixes (networking, backport from 0.4.0.2-alpha):
        - Gracefully handle empty username/password fields in SOCKS5
          username/password auth messsage and allow SOCKS5 handshake to
          continue. Previously, we had rejected these handshakes, breaking
          certain applications. Fixes bug 29175; bugfix on 0.3.5.1-alpha.
    
      o Minor features (compilation, backport from 0.4.0.2-alpha):
        - Compile correctly when OpenSSL is built with engine support
          disabled, or with deprecated APIs disabled. Closes ticket 29026.
          Patches from "Mangix".
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 5 2019 Maxmind GeoLite2
          Country database. Closes ticket 29478.
    
      o Minor features (testing, backport from 0.4.0.2-alpha):
        - Treat all unexpected ERR and BUG messages as test failures. Closes
          ticket 28668.
    
      o Minor bugfixes (onion service v3, client, backport from 0.4.0.1-alpha):
        - Stop logging a "BUG()" warning and stacktrace when we find a SOCKS
          connection waiting for a descriptor that we actually have in the
          cache. It turns out that this can actually happen, though it is
          rare. Now, tor will recover and retry the descriptor. Fixes bug
          28669; bugfix on 0.3.2.4-alpha.
    
      o Minor bugfixes (IPv6, backport from 0.4.0.1-alpha):
        - Fix tor_ersatz_socketpair on IPv6-only systems. Previously, the
          IPv6 socket was bound using an address family of AF_INET instead
          of AF_INET6. Fixes bug 28995; bugfix on 0.3.5.1-alpha. Patch from
          Kris Katterjohn.
    
      o Minor bugfixes (build, compatibility, rust, backport from 0.4.0.2-alpha):
        - Update Cargo.lock file to match the version made by the latest
          version of Rust, so that "make distcheck" will pass again. Fixes
          bug 29244; bugfix on 0.3.3.4-alpha.
    
      o Minor bugfixes (client, clock skew, backport from 0.4.0.1-alpha):
        - Select guards even if the consensus has expired, as long as the
          consensus is still reasonably live. Fixes bug 24661; bugfix
          on 0.3.0.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.4.0.1-alpha):
        - Compile correctly on OpenBSD; previously, we were missing some
          headers required in order to detect it properly. Fixes bug 28938;
          bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn.
    
      o Minor bugfixes (documentation, backport from 0.4.0.2-alpha):
        - Describe the contents of the v3 onion service client authorization
          files correctly: They hold public keys, not private keys. Fixes
          bug 28979; bugfix on 0.3.5.1-alpha. Spotted by "Felixix".
    
      o Minor bugfixes (logging, backport from 0.4.0.1-alpha):
        - Rework rep_hist_log_link_protocol_counts() to iterate through all
          link protocol versions when logging incoming/outgoing connection
          counts. Tor no longer skips version 5, and we won't have to
          remember to update this function when new link protocol version is
          developed. Fixes bug 28920; bugfix on 0.2.6.10.
    
      o Minor bugfixes (logging, backport from 0.4.0.2-alpha):
        - Log more information at "warning" level when unable to read a
          private key; log more information at "info" level when unable to
          read a public key. We had warnings here before, but they were lost
          during our NSS work. Fixes bug 29042; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (misc, backport from 0.4.0.2-alpha):
        - The amount of total available physical memory is now determined
          using the sysctl identifier HW_PHYSMEM (rather than HW_USERMEM)
          when it is defined and a 64-bit variant is not available. Fixes
          bug 28981; bugfix on 0.2.5.4-alpha. Patch from Kris Katterjohn.
    
      o Minor bugfixes (onion services, backport from 0.4.0.2-alpha):
        - Avoid crashing if ClientOnionAuthDir (incorrectly) contains more
          than one private key for a hidden service. Fixes bug 29040; bugfix
          on 0.3.5.1-alpha.
        - In hs_cache_store_as_client() log an HSDesc we failed to parse at
          "debug" level. Tor used to log it as a warning, which caused very
          long log lines to appear for some users. Fixes bug 29135; bugfix
          on 0.3.2.1-alpha.
        - Stop logging "Tried to establish rendezvous on non-OR circuit..."
          as a warning. Instead, log it as a protocol warning, because there
          is nothing that relay operators can do to fix it. Fixes bug 29029;
          bugfix on 0.2.5.7-rc.
    
      o Minor bugfixes (tests, directory clients, backport from 0.4.0.1-alpha):
        - Mark outdated dirservers when Tor only has a reasonably live
          consensus. Fixes bug 28569; bugfix on 0.3.2.5-alpha.
    
      o Minor bugfixes (tests, backport from 0.4.0.2-alpha):
        - Detect and suppress "bug" warnings from the util/time test on
          Windows. Fixes bug 29161; bugfix on 0.2.9.3-alpha.
        - Do not log an error-level message if we fail to find an IPv6
          network interface from the unit tests. Fixes bug 29160; bugfix
          on 0.2.7.3-rc.
    
      o Minor bugfixes (usability, backport from 0.4.0.1-alpha):
        - Stop saying "Your Guard ..." in pathbias_measure_{use,close}_rate().
          Some users took this phrasing to mean that the mentioned guard was
          under their control or responsibility, which it is not. Fixes bug
          28895; bugfix on Tor 0.3.0.1-alpha.
    
    
    Changes in version 0.3.4.11 - 2019-02-21
      Tor 0.3.4.11 is the third stable release in its series.  It includes
      a fix for a medium-severity security bug affecting Tor 0.3.2.1-alpha and
      later. All Tor instances running an affected release should upgrade to
      0.3.3.12, 0.3.4.11, 0.3.5.8, or 0.4.0.2-alpha.
    
      o Major bugfixes (cell scheduler, KIST, security):
        - Make KIST consider the outbuf length when computing what it can
          put in the outbuf. Previously, KIST acted as though the outbuf
          were empty, which could lead to the outbuf becoming too full. It
          is possible that an attacker could exploit this bug to cause a Tor
          client or relay to run out of memory and crash. Fixes bug 29168;
          bugfix on 0.3.2.1-alpha. This issue is also being tracked as
          TROVE-2019-001 and CVE-2019-8955.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 5 2019 Maxmind GeoLite2
          Country database. Closes ticket 29478.
    
      o Minor bugfixes (build, compatibility, rust, backport from 0.4.0.2-alpha):
        - Update Cargo.lock file to match the version made by the latest
          version of Rust, so that "make distcheck" will pass again. Fixes
          bug 29244; bugfix on 0.3.3.4-alpha.
    
      o Minor bugfixes (onion services, backport from 0.4.0.2-alpha):
        - Stop logging "Tried to establish rendezvous on non-OR circuit..."
          as a warning. Instead, log it as a protocol warning, because there
          is nothing that relay operators can do to fix it. Fixes bug 29029;
          bugfix on 0.2.5.7-rc.
    
    
    Changes in version 0.3.3.12 - 2019-02-21
      Tor 0.3.3.12 fixes a medium-severity security bug affecting Tor
      0.3.2.1-alpha and later. All Tor instances running an affected release
      should upgrade to 0.3.3.12, 0.3.4.11, 0.3.5.8, or 0.4.0.2-alpha.
    
      This release marks the end of support for the Tor 0.3.3.x series. We
      recommend that users switch to either the Tor 0.3.4 series (supported
      until at least 10 June 2019), or the Tor 0.3.5 series, which will
      receive long-term support until at least 1 Feb 2022.
    
      o Major bugfixes (cell scheduler, KIST, security):
        - Make KIST consider the outbuf length when computing what it can
          put in the outbuf. Previously, KIST acted as though the outbuf
          were empty, which could lead to the outbuf becoming too full. It
          is possible that an attacker could exploit this bug to cause a Tor
          client or relay to run out of memory and crash. Fixes bug 29168;
          bugfix on 0.3.2.1-alpha. This issue is also being tracked as
          TROVE-2019-001 and CVE-2019-8955.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 5 2019 Maxmind GeoLite2
          Country database. Closes ticket 29478.
    
      o Minor bugfixes (build, compatibility, rust, backport from 0.4.0.2-alpha):
        - Update Cargo.lock file to match the version made by the latest
          version of Rust, so that "make distcheck" will pass again. Fixes
          bug 29244; bugfix on 0.3.3.4-alpha.
    
      o Minor bugfixes (onion services, backport from 0.4.0.2-alpha):
        - Stop logging "Tried to establish rendezvous on non-OR circuit..."
          as a warning. Instead, log it as a protocol warning, because there
          is nothing that relay operators can do to fix it. Fixes bug 29029;
          bugfix on 0.2.5.7-rc.
    
    
    Changes in version 0.3.3.11 - 2019-01-07
      Tor 0.3.3.11 backports numerous fixes from later versions of Tor.
      numerous fixes, including an important fix for anyone using OpenSSL
      1.1.1. Anyone running an earlier version of Tor 0.3.3 should upgrade
      to this version, or to a later series.
    
      As a reminder, support the Tor 0.3.3 series will end on 22 Feb 2019.
      We anticipate that this will be the last release of Tor 0.3.3, unless
      some major bug is before then. Some time between now and then, users
      should switch to either the Tor 0.3.4 series (supported until at least
      10 June 2019), or the Tor 0.3.5 series, which will receive long-term
      support until at least 1 Feb 2022.
    
      o Major bugfixes (OpenSSL, portability, backport from 0.3.5.5-alpha):
        - Fix our usage of named groups when running as a TLS 1.3 client in
          OpenSSL 1.1.1. Previously, we only initialized EC groups when
          running as a relay, which caused clients to fail to negotiate TLS
          1.3 with relays. Fixes bug 28245; bugfix on 0.2.9.15 (when TLS 1.3
          support was added).
    
      o Major bugfixes (restart-in-process, backport from 0.3.5.1-alpha):
        - Fix a use-after-free error that could be caused by passing Tor an
          impossible set of options that would fail during options_act().
          Fixes bug 27708; bugfix on 0.3.3.1-alpha.
    
      o Minor features (continuous integration, backport from 0.3.5.1-alpha):
        - Only run one online rust build in Travis, to reduce network
          errors. Skip offline rust builds on Travis for Linux gcc, because
          they're redundant. Implements ticket 27252.
        - Skip gcc on OSX in Travis CI, because it's rarely used. Skip a
          duplicate hardening-off build in Travis on Tor 0.2.9. Skip gcc on
          Linux with default settings, because all the non-default builds
          use gcc on Linux. Implements ticket 27252.
    
      o Minor features (continuous integration, backport from 0.3.5.3-alpha):
        - Use the Travis Homebrew addon to install packages on macOS during
          Travis CI. The package list is the same, but the Homebrew addon
          does not do a `brew update` by default. Implements ticket 27738.
    
      o Minor features (fallback directory list, backport from 0.3.5.6-rc):
        - Replace the 150 fallbacks originally introduced in Tor
          0.3.3.1-alpha in January 2018 (of which ~115 were still
          functional), with a list of 157 fallbacks (92 new, 65 existing, 85
          removed) generated in December 2018. Closes ticket 24803.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the January 3 2019 Maxmind GeoLite2
          Country database. Closes ticket 29012.
    
      o Minor features (OpenSSL bug workaround, backport from 0.3.5.7):
        - Work around a bug in OpenSSL 1.1.1a, which prevented the TLS 1.3
          key export function from handling long labels. When this bug is
          detected, Tor will disable TLS 1.3. We recommend upgrading to a
          version of OpenSSL without this bug when it becomes available.
          Closes ticket 28973.
    
      o Minor bugfixes (relay statistics, backport from 0.3.5.7):
        - Update relay descriptor on bandwidth changes only when the uptime
          is smaller than 24h, in order to reduce the efficiency of guard
          discovery attacks. Fixes bug 24104; bugfix on 0.1.1.6-alpha.
    
      o Minor bugfixes (C correctness, backport from 0.3.5.4-alpha):
        - Avoid undefined behavior in an end-of-string check when parsing
          the BEGIN line in a directory object. Fixes bug 28202; bugfix
          on 0.2.0.3-alpha.
    
      o Minor bugfixes (code safety, backport from 0.3.5.3-alpha):
        - Rewrite our assertion macros so that they no longer suppress the
          compiler's -Wparentheses warnings. Fixes bug 27709; bugfix
    
      o Minor bugfixes (compilation, backport from 0.3.5.5-alpha):
        - Initialize a variable unconditionally in aes_new_cipher(), since
          some compilers cannot tell that we always initialize it before
          use. Fixes bug 28413; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (directory authority, backport from 0.3.5.4-alpha):
        - Log additional info when we get a relay that shares an ed25519 ID
          with a different relay, instead making a BUG() warning. Fixes bug
          27800; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (directory permissions, backport form 0.3.5.3-alpha):
        - When a user requests a group-readable DataDirectory, give it to
          them. Previously, when the DataDirectory and the CacheDirectory
          were the same, the default setting (0) for
          CacheDirectoryGroupReadable would override the setting for
          DataDirectoryGroupReadable. Fixes bug 26913; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (onion service v3, backport from 0.3.5.1-alpha):
        - When the onion service directory can't be created or has the wrong
          permissions, do not log a stack trace. Fixes bug 27335; bugfix
          on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion service v3, backport from 0.3.5.2-alpha):
        - Close all SOCKS request (for the same .onion) if the newly fetched
          descriptor is unusable. Before that, we would close only the first
          one leaving the other hanging and let to time out by themselves.
          Fixes bug 27410; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion service v3, backport from 0.3.5.3-alpha):
        - Don't warn so loudly when Tor is unable to decode an onion
          descriptor. This can now happen as a normal use case if a client
          gets a descriptor with client authorization but the client is not
          authorized. Fixes bug 27550; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (onion service v3, backport from 0.3.5.6-rc):
        - When deleting an ephemeral onion service (DEL_ONION), do not close
          any rendezvous circuits in order to let the existing client
          connections finish by themselves or closed by the application. The
          HS v2 is doing that already so now we have the same behavior for
          all versions. Fixes bug 28619; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (HTTP tunnel):
        - Fix a bug warning when closing an HTTP tunnel connection due to
          an HTTP request we couldn't handle. Fixes bug 26470; bugfix on
          0.3.2.1-alpha.
    
      o Minor bugfixes (memory leaks, backport from 0.3.5.5-alpha):
        - Fix a harmless memory leak in libtorrunner.a. Fixes bug 28419;
          bugfix on 0.3.3.1-alpha. Patch from Martin Kepplinger.
    
      o Minor bugfixes (netflow padding, backport from 0.3.5.1-alpha):
        - Ensure circuitmux queues are empty before scheduling or sending
          padding. Fixes bug 25505; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (protover, backport from 0.3.5.3-alpha):
        - Reject protocol names containing bytes other than alphanumeric
          characters and hyphens ([A-Za-z0-9-]). Fixes bug 27316; bugfix
          on 0.2.9.4-alpha.
    
      o Minor bugfixes (rust, backport from 0.3.5.1-alpha):
        - Compute protover votes correctly in the rust version of the
          protover code. Previously, the protover rewrite in 24031 allowed
          repeated votes from the same voter for the same protocol version
          to be counted multiple times in protover_compute_vote(). Fixes bug
          27649; bugfix on 0.3.3.5-rc.
        - Reject protover names that contain invalid characters. Fixes bug
          27687; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (rust, backport from 0.3.5.2-alpha):
        - protover_all_supported() would attempt to allocate up to 16GB on
          some inputs, leading to a potential memory DoS. Fixes bug 27206;
          bugfix on 0.3.3.5-rc.
    
      o Minor bugfixes (rust, backport from 0.3.5.4-alpha):
        - Fix a potential null dereference in protover_all_supported(). Add
          a test for it. Fixes bug 27804; bugfix on 0.3.3.1-alpha.
        - Return a string that can be safely freed by C code, not one
          created by the rust allocator, in protover_all_supported(). Fixes
          bug 27740; bugfix on 0.3.3.1-alpha.
        - Fix an API mismatch in the rust implementation of
          protover_compute_vote(). This bug could have caused crashes on any
          directory authorities running Tor with Rust (which we do not yet
          recommend). Fixes bug 27741; bugfix on 0.3.3.6.
    
      o Minor bugfixes (testing, backport from 0.3.5.1-alpha):
        - If a unit test running in a subprocess exits abnormally or with a
          nonzero status code, treat the test as having failed, even if the
          test reported success. Without this fix, memory leaks don't cause
          the tests to fail, even with LeakSanitizer. Fixes bug 27658;
          bugfix on 0.2.2.4-alpha.
    
      o Minor bugfixes (testing, backport from 0.3.5.4-alpha):
        - Treat backtrace test failures as expected on BSD-derived systems
          (NetBSD, OpenBSD, and macOS/Darwin) until we solve bug 17808.
          (FreeBSD failures have been treated as expected since 18204 in
          0.2.8.) Fixes bug 27948; bugfix on 0.2.5.2-alpha.
    
      o Minor bugfixes (unit tests, guard selection, backport from 0.3.5.6-rc):
        - Stop leaking memory in an entry guard unit test. Fixes bug 28554;
          bugfix on 0.3.0.1-alpha.
    
    
    Changes in version 0.3.4.10 - 2019-01-07
      Tor 0.3.4.9 is the second stable release in its series; it backports
      numerous fixes, including an important fix for relays, and for anyone
      using OpenSSL 1.1.1. Anyone running an  earlier version of Tor 0.3.4
      should upgrade.
    
      As a reminder, the Tor 0.3.4 series will be supported until 10 June
      2019. Some time between now and then, users should switch to the Tor
      0.3.5 series, which will receive long-term support until at least 1
      Feb 2022.
    
      o Major bugfixes (OpenSSL, portability, backport from 0.3.5.5-alpha):
        - Fix our usage of named groups when running as a TLS 1.3 client in
          OpenSSL 1.1.1. Previously, we only initialized EC groups when
          running as a relay, which caused clients to fail to negotiate TLS
          1.3 with relays. Fixes bug 28245; bugfix on 0.2.9.15 (when TLS 1.3
          support was added).
    
      o Major bugfixes (relay, directory, backport from 0.3.5.7):
        - Always reactivate linked connections in the main loop so long as
          any linked connection has been active. Previously, connections
          serving directory information wouldn't get reactivated after the
          first chunk of data was sent (usually 32KB), which would prevent
          clients from bootstrapping. Fixes bug 28912; bugfix on
          0.3.4.1-alpha. Patch by "cypherpunks3".
    
      o Minor features (continuous integration, Windows, backport from 0.3.5.6-rc):
        - Always show the configure and test logs, and upload them as build
          artifacts, when building for Windows using Appveyor CI.
          Implements 28459.
    
      o Minor features (controller, backport from 0.3.5.1-alpha):
        - For purposes of CIRC_BW-based dropped cell detection, track half-
          closed stream ids, and allow their ENDs, SENDMEs, DATA and path
          bias check cells to arrive without counting it as dropped until
          either the END arrives, or the windows are empty. Closes
          ticket 25573.
    
      o Minor features (fallback directory list, backport from 0.3.5.6-rc):
        - Replace the 150 fallbacks originally introduced in Tor
          0.3.3.1-alpha in January 2018 (of which ~115 were still
          functional), with a list of 157 fallbacks (92 new, 65 existing, 85
          removed) generated in December 2018. Closes ticket 24803.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the November 6 2018 Maxmind GeoLite2
          Country database. Closes ticket 28395.
    
      o Minor features (OpenSSL bug workaround, backport from 0.3.5.7):
        - Work around a bug in OpenSSL 1.1.1a, which prevented the TLS 1.3
          key export function from handling long labels. When this bug is
          detected, Tor will disable TLS 1.3. We recommend upgrading to a
          version of OpenSSL without this bug when it becomes available.
          Closes ticket 28973.
    
      o Minor bugfixes (compilation, backport from 0.3.5.5-alpha):
        - Initialize a variable unconditionally in aes_new_cipher(), since
          some compilers cannot tell that we always initialize it before
          use. Fixes bug 28413; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (connection, relay, backport from 0.3.5.5-alpha):
        - Avoid a logging a BUG() stacktrace when closing connection held
          open because the write side is rate limited but not the read side.
          Now, the connection read side is simply shut down until Tor is
          able to flush the connection and close it. Fixes bug 27750; bugfix
          on 0.3.4.1-alpha.
    
      o Minor bugfixes (continuous integration, Windows, backport from 0.3.5.5-alpha):
        - Manually configure the zstd compiler options, when building using
          mingw on Appveyor Windows CI. The MSYS2 mingw zstd package does
          not come with a pkg-config file. Fixes bug 28454; bugfix
          on 0.3.4.1-alpha.
        - Stop using an external OpenSSL install, and stop installing MSYS2
          packages, when building using mingw on Appveyor Windows CI. Fixes
          bug 28399; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (continuous integration, Windows, backport from 0.3.5.6-rc):
        - Explicitly specify the path to the OpenSSL library and do not
          download OpenSSL from Pacman, but instead use the library that is
          already provided by AppVeyor. Fixes bug 28574; bugfix on master.
    
      o Minor bugfixes (directory permissions, backport form 0.3.5.3-alpha):
        - When a user requests a group-readable DataDirectory, give it to
          them. Previously, when the DataDirectory and the CacheDirectory
          were the same, the default setting (0) for
          CacheDirectoryGroupReadable would override the setting for
          DataDirectoryGroupReadable. Fixes bug 26913; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (memory leaks, backport from 0.3.5.5-alpha):
        - Fix a harmless memory leak in libtorrunner.a. Fixes bug 28419;
          bugfix on 0.3.3.1-alpha. Patch from Martin Kepplinger.
    
      o Minor bugfixes (onion service v3, backport from 0.3.5.3-alpha):
        - Don't warn so loudly when Tor is unable to decode an onion
          descriptor. This can now happen as a normal use case if a client
          gets a descriptor with client authorization but the client is not
          authorized. Fixes bug 27550; bugfix on 0.3.5.1-alpha.
    
      o Minor bugfixes (onion service v3, backport from 0.3.5.6-rc):
        - When deleting an ephemeral onion service (DEL_ONION), do not close
          any rendezvous circuits in order to let the existing client
          connections finish by themselves or closed by the application. The
          HS v2 is doing that already so now we have the same behavior for
          all versions. Fixes bug 28619; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (relay statistics, backport from 0.3.5.7):
        - Update relay descriptor on bandwidth changes only when the uptime
          is smaller than 24h, in order to reduce the efficiency of guard
          discovery attacks. Fixes bug 24104; bugfix on 0.1.1.6-alpha.
    
      o Minor bugfixes (unit tests, guard selection, backport from 0.3.5.6-rc):
        - Stop leaking memory in an entry guard unit test. Fixes bug 28554;
          bugfix on 0.3.0.1-alpha.
    
    
    Changes in version 0.3.5.7 - 2019-01-07
      Tor 0.3.5.7 is the first stable release in its series; it includes
      compilation and portability fixes, and a fix for a severe problem
      affecting directory caches.
    
      The Tor 0.3.5 series includes several new features and performance
      improvements, including client authorization for v3 onion services,
      cleanups to bootstrap reporting, support for improved bandwidth-
      measurement tools, experimental support for NSS in place of OpenSSL,
      and much more. It also begins a full reorganization of Tor's code
      layout, for improved modularity and maintainability in the future.
      Finally, there is the usual set of performance improvements and
      bugfixes that we try to do in every release series.
    
      There are a couple of changes in the 0.3.5 that may affect
      compatibility. First, the default version for newly created onion
      services is now v3. Use the HiddenServiceVersion option if you want to
      override this. Second, some log messages related to bootstrapping have
      changed; if you use stem, you may need to update to the latest version
      so it will recognize them.
    
      We have designated 0.3.5 as a "long-term support" (LTS) series: we
      will continue to patch major bugs in typical configurations of 0.3.5
      until at least 1 Feb 2022. (We do not plan to provide long-term
      support for embedding, Rust support, NSS support, running a directory
      authority, or unsupported platforms. For these, you will need to stick
      with the latest stable release.)
    
      Below are the changes since 0.3.4.9. For a complete list of changes
      since 0.3.5.6-rc, see the ChangeLog file.
    
      o Major features (bootstrap):
        - Don't report directory progress until after a connection to a
          relay or bridge has succeeded. Previously, we'd report 80%
          progress based on cached directory information when we couldn't
          even connect to the network. Closes ticket 27169.
    
      o Major features (new code layout):
        - Nearly all of Tor's source code has been moved around into more
          logical places. The "common" directory is now divided into a set
          of libraries in "lib", and files in the "or" directory have been
          split into "core" (logic absolutely needed for onion routing),
          "feature" (independent modules in Tor), and "app" (to configure
          and invoke the rest of Tor). See doc/HACKING/CodeStructure.md for
          more information. Closes ticket 26481.
    
          This refactoring is not complete: although the libraries have been
          refactored to be acyclic, the main body of Tor is still too
          interconnected. We will attempt to improve this in the future.
    
      o Major features (onion services v3):
        - Implement onion service client authorization at the descriptor
          level: only authorized clients can decrypt a service's descriptor
          to find out how to contact it. A new torrc option was added to
          control this client side: ClientOnionAuthDir <path>. On the
          service side, if the "authorized_clients/" directory exists in the
          onion service directory path, client configurations are read from
          the files within. See the manpage for more details. Closes ticket
          27547. Patch done by Suphanat Chunhapanya (haxxpop).
        - Improve revision counter generation in next-gen onion services.
          Onion services can now scale by hosting multiple instances on
          different hosts without synchronization between them, which was
          previously impossible because descriptors would get rejected by
          HSDirs. Addresses ticket 25552.
        - Version 3 onion services can now use the per-service
          HiddenServiceExportCircuitID option to differentiate client
          circuits. It communicates with the service by using the HAProxy
          protocol to assign virtual IP addresses to inbound client
          circuits. Closes ticket 4700. Patch by Mahrud Sayrafi.
    
      o Major features (onion services, UI change):
        - For a newly created onion service, the default version is now 3.
          Tor still supports existing version 2 services, but the operator
          now needs to set "HiddenServiceVersion 2" in order to create a new
          version 2 service. For existing services, Tor now learns the
          version by reading the key file. Closes ticket 27215.
    
      o Major features (portability, cryptography, experimental, TLS):
        - Tor now has the option to compile with the NSS library instead of
          OpenSSL. This feature is experimental, and we expect that bugs may
          remain. It is mainly intended for environments where Tor's
          performance is not CPU-bound, and where NSS is already known to be
          installed. To try it out, configure Tor with the --enable-nss
          flag. Closes tickets 26631, 26815, and 26816.
    
          If you are experimenting with this option and using an old cached
          consensus, Tor may fail to start. To solve this, delete your
          "cached-consensus" and "cached-microdesc-consensus" files,
          (if present), and restart Tor.
    
      o Major features (relay, UI change):
        - Relays no longer run as exits by default. If the "ExitRelay"
          option is auto (or unset), and no exit policy is specified with
          ExitPolicy or ReducedExitPolicy, we now treat ExitRelay as 0.
          Previously in this case, we allowed exit traffic and logged a
          warning message. Closes ticket 21530. Patch by Neel Chauhan.
        - Tor now validates that the ContactInfo config option is valid UTF-
          8 when parsing torrc. Closes ticket 27428.
    
      o Major bugfixes (compilation):
        - Fix compilation on ARM (and other less-used CPUs) when compiling
          with OpenSSL before 1.1. Fixes bug 27781; bugfix on 0.3.4.1-alpha.
    
      o Major bugfixes (compilation, rust):
        - Rust tests can now build and run successfully with the
          --enable-fragile-hardening option enabled. Doing this currently
          requires the rust beta channel; it will be possible with stable
          rust once Rust version 1.31 is released. Patch from Alex Crichton.
          Fixes bugs 27272, 27273, and 27274. Bugfix on 0.3.1.1-alpha.
    
      o Major bugfixes (directory authority):
        - Actually check that the address we get from DirAuthority
          configuration line is valid IPv4. Explicitly disallow DirAuthority
          address to be a DNS hostname. Fixes bug 26488; bugfix
          on 0.1.2.10-rc.
    
      o Major bugfixes (embedding, main loop):
        - When DisableNetwork becomes set, actually disable periodic events
          that are already enabled. (Previously, we would refrain from
          enabling new ones, but we would leave the old ones turned on.)
          Fixes bug 28348; bugfix on 0.3.4.1-alpha.
    
      o Major bugfixes (main loop, bootstrap):
        - Make sure Tor bootstraps and works properly if only the
          ControlPort is set. Prior to this fix, Tor would only bootstrap
          when a client port was set (Socks, Trans, NATD, DNS or HTTPTunnel
          port). Fixes bug 27849; bugfix on 0.3.4.1-alpha.
    
      o Major bugfixes (onion service v3):
        - On an intro point for a version 3 onion service, stop closing
          introduction circuits on a NACK. This lets the client decide
          whether to reuse the circuit or discard it. Previously, we closed
          intro circuits when sending NACKs. Fixes bug 27841; bugfix on
          0.3.2.1-alpha. Patch by Neel Chaunan.
    
      o Major bugfixes (OpenSSL, portability):
        - Fix our usage of named groups when running as a TLS 1.3 client in
          OpenSSL 1.1.1. Previously, we only initialized EC groups when
          running as a relay, which caused clients to fail to negotiate TLS
          1.3 with relays. Fixes bug 28245; bugfix on 0.2.9.15 (when TLS 1.3
          support was added).
    
      o Major bugfixes (relay bandwidth statistics):
        - When we close relayed circuits, report the data in the circuit
          queues as being written in our relay bandwidth stats. This
          mitigates guard discovery and other attacks that close circuits
          for the explicit purpose of noticing this discrepancy in
          statistics. Fixes bug 23512; bugfix on 0.0.8pre3.
    
      o Major bugfixes (relay):
        - When our write bandwidth limit is exhausted, stop writing on the
          connection. Previously, we had a typo in the code that would make
          us stop reading instead, leading to relay connections being stuck
          indefinitely and consuming kernel RAM. Fixes bug 28089; bugfix
          on 0.3.4.1-alpha.
        - Always reactivate linked connections in the main loop so long as
          any linked connection has been active. Previously, connections
          serving directory information wouldn't get reactivated after the
          first chunk of data was sent (usually 32KB), which would prevent
          clients from bootstrapping. Fixes bug 28912; bugfix on
          0.3.4.1-alpha. Patch by "cypherpunks3".
    
      o Major bugfixes (restart-in-process):
        - Fix a use-after-free error that could be caused by passing Tor an
          impossible set of options that would fail during options_act().
          Fixes bug 27708; bugfix on 0.3.3.1-alpha.
    
      o Minor features (admin tools):
        - Add a new --key-expiration option to print the expiration date of
          the signing cert in an ed25519_signing_cert file. Resolves
          issue 19506.
    
      o Minor features (build):
        - If you pass the "--enable-pic" option to configure, Tor will try
          to tell the compiler to build position-independent code suitable
          to link into a dynamic library. (The default remains -fPIE, for
          code suitable for a relocatable executable.) Closes ticket 23846.
    
      o Minor features (code correctness, testing):
        - Tor's build process now includes a "check-includes" make target to
          verify that no module of Tor relies on any headers from a higher-
          level module. We hope to use this feature over time to help
          refactor our codebase. Closes ticket 26447.
    
      o Minor features (code layout):
        - We have a new "lowest-level" error-handling API for use by code
          invoked from within the logging module. With this interface, the
          logging code is no longer at risk of calling into itself if a
          failure occurs while it is trying to log something. Closes
          ticket 26427.
    
      o Minor features (compilation):
        - When possible, place our warning flags in a separate file, to
          avoid flooding verbose build logs. Closes ticket 28924.
        - Tor's configure script now supports a --with-malloc= option to
          select your malloc implementation. Supported options are
          "tcmalloc", "jemalloc", "openbsd" (deprecated), and "system" (the
          default). Addresses part of ticket 20424. Based on a patch from
          Alex Xu.
    
      o Minor features (config):
        - The "auto" keyword in torrc is now case-insensitive. Closes
          ticket 26663.
    
      o Minor features (continuous integration):
        - Add a Travis CI build for --enable-nss on Linux gcc. Closes
          ticket 27751.
        - Add new CI job to Travis configuration to run stem-based
          integration tests. Closes ticket 27913.
        - Use the Travis Homebrew addon to install packages on macOS during
          Travis CI. The package list is the same, but the Homebrew addon
          does not do a `brew update` by default. Implements ticket 27738.
        - Report what program produced the mysterious core file that we
          occasionally see on Travis CI during make distcheck. Closes
          ticket 28024.
        - Don't do a distcheck with --disable-module-dirauth in Travis.
          Implements ticket 27252.
        - Install libcap-dev and libseccomp2-dev so these optional
          dependencies get tested on Travis CI. Closes ticket 26560.
        - Only run one online rust build in Travis, to reduce network
          errors. Skip offline rust builds on Travis for Linux gcc, because
          they're redundant. Implements ticket 27252.
        - Skip gcc on OSX in Travis CI, because it's rarely used. Skip a
          duplicate hardening-off build in Travis on Tor 0.2.9. Skip gcc on
          Linux with default settings, because all the non-default builds
          use gcc on Linux. Implements ticket 27252.
    
      o Minor features (continuous integration, Windows):
        - Always show the configure and test logs, and upload them as build
          artifacts, when building for Windows using Appveyor CI.
          Implements 28459.
        - Build tor on Windows Server 2012 R2 and Windows Server 2016 using
          Appveyor's CI. Closes ticket 28318.
    
      o Minor features (controller):
        - Emit CIRC_BW events as soon as we detect that we processed an
          invalid or otherwise dropped cell on a circuit. This allows
          vanguards and other controllers to react more quickly to dropped
          cells. Closes ticket 27678.
        - For purposes of CIRC_BW-based dropped cell detection, track half-
          closed stream ids, and allow their ENDs, SENDMEs, DATA and path
          bias check cells to arrive without counting it as dropped until
          either the END arrives, or the windows are empty. Closes
          ticket 25573.
        - Implement a 'GETINFO md/all' controller command to enable getting
          all known microdescriptors. Closes ticket 8323.
        - The GETINFO command now support an "uptime" argument, to return
          Tor's uptime in seconds. Closes ticket 25132.
    
      o Minor features (denial-of-service avoidance):
        - Make our OOM handler aware of the DNS cache so that it doesn't
          fill up the memory. This check is important for our DoS mitigation
          subsystem. Closes ticket 18642. Patch by Neel Chauhan.
    
      o Minor features (development):
        - Tor's makefile now supports running the "clippy" Rust style tool
          on our Rust code. Closes ticket 22156.
    
      o Minor features (directory authority):
        - There is no longer an artificial upper limit on the length of
          bandwidth lines. Closes ticket 26223.
        - When a bandwidth file is used to obtain the bandwidth measurements,
          include this bandwidth file headers in the votes. Closes
          ticket 3723.
        - Improved support for networks with only a single authority or a
          single fallback directory. Patch from Gabriel Somlo. Closes
          ticket 25928.
    
      o Minor features (embedding API):
        - The Tor controller API now supports a function to launch Tor with
          a preconstructed owning controller FD, so that embedding
          applications don't need to manage controller ports and
          authentication. Closes ticket 24204.
        - The Tor controller API now has a function that returns the name
          and version of the backend implementing the API. Closes
          ticket 26947.
    
      o Minor features (fallback directory list):
        - Replace the 150 fallbacks originally introduced in Tor
          0.3.3.1-alpha in January 2018 (of which ~115 were still
          functional), with a list of 157 fallbacks (92 new, 65 existing, 85
          removed) generated in December 2018. Closes ticket 24803.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the January 3 2019 Maxmind GeoLite2
          Country database. Closes ticket 29012.
    
      o Minor features (memory management):
        - Get Libevent to use the same memory allocator as Tor, by calling
          event_set_mem_functions() during initialization. Resolves
          ticket 8415.
    
      o Minor features (memory usage):
        - When not using them, store legacy TAP public onion keys in DER-
          encoded format, rather than as expanded public keys. This should
          save several megabytes on typical clients. Closes ticket 27246.
    
      o Minor features (OpenSSL bug workaround):
        - Work around a bug in OpenSSL 1.1.1a, which prevented the TLS 1.3
          key export function from handling long labels. When this bug is
          detected, Tor will disable TLS 1.3. We recommend upgrading to a
          version of OpenSSL without this bug when it becomes available.
          Closes ticket 28973.
    
      o Minor features (OpenSSL):
        - When possible, use RFC5869 HKDF implementation from OpenSSL rather
          than our own. Resolves ticket 19979.
    
      o Minor features (performance):
        - Remove about 96% of the work from the function that we run at
          startup to test our curve25519_basepoint implementation. Since
          this function has yet to find an actual failure, we now only run
          it for 8 iterations instead of 200. Based on our profile
          information, this change should save around 8% of our startup time
          on typical desktops, and may have a similar effect on other
          platforms. Closes ticket 28838.
        - Stop re-validating our hardcoded Diffie-Hellman parameters on
          every startup. Doing this wasted time and cycles, especially on
          low-powered devices. Closes ticket 28851.
    
      o Minor features (Rust, code quality):
        - Improve rust code quality in the rust protover implementation by
          making it more idiomatic. Includes changing an internal API to
          take &str instead of &String. Closes ticket 26492.
    
      o Minor features (testing):
        - Add scripts/test/chutney-git-bisect.sh, for bisecting using
          chutney. Implements ticket 27211.
    
      o Minor features (tor-resolve):
        - The tor-resolve utility can now be used with IPv6 SOCKS proxies.
          Side-effect of the refactoring for ticket 26526.
    
      o Minor features (UI):
        - Log each included configuration file or directory as we read it,
          to provide more visibility about where Tor is reading from. Patch
          from Unto Sten; closes ticket 27186.
        - Lower log level of "Scheduler type KIST has been enabled" to INFO.
          Closes ticket 26703.
    
      o Minor bugfixes (32-bit OSX and iOS, timing):
        - Fix an integer overflow bug in our optimized 32-bit millisecond-
          difference algorithm for 32-bit Apple platforms. Previously, it
          would overflow when calculating the difference between two times
          more than 47 days apart. Fixes part of bug 27139; bugfix
          on 0.3.4.1-alpha.
        - Improve the precision of our 32-bit millisecond difference
          algorithm for 32-bit Apple platforms. Fixes part of bug 27139;
          bugfix on 0.3.4.1-alpha.
        - Relax the tolerance on the mainloop/update_time_jumps test when
          running on 32-bit Apple platforms. Fixes part of bug 27139; bugfix
          on 0.3.4.1-alpha.
    
      o Minor bugfixes (bootstrap):
        - Try harder to get descriptors in non-exit test networks, by using
          the mid weight for the third hop when there are no exits. Fixes
          bug 27237; bugfix on 0.2.6.2-alpha.
    
      o Minor bugfixes (C correctness):
        - Avoid casting smartlist index to int implicitly, as it may trigger
          a warning (-Wshorten-64-to-32). Fixes bug 26282; bugfix on
          0.2.3.13-alpha, 0.2.7.1-alpha and 0.2.1.1-alpha.
        - Use time_t for all values in
          predicted_ports_prediction_time_remaining(). Rework the code that
          computes difference between durations/timestamps. Fixes bug 27165;
          bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (client, memory usage):
        - When not running as a directory cache, there is no need to store
          the text of the current consensus networkstatus in RAM.
          Previously, however, clients would store it anyway, at a cost of
          over 5 MB. Now, they do not. Fixes bug 27247; bugfix
          on 0.3.0.1-alpha.
    
      o Minor bugfixes (client, ReachableAddresses):
        - Instead of adding a "reject *:*" line to ReachableAddresses when
          loading the configuration, add one to the policy after parsing it
          in parse_reachable_addresses(). This prevents extra "reject *.*"
          lines from accumulating on reloads. Fixes bug 20874; bugfix on
          0.1.1.5-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (code quality):
        - Rename sandbox_getaddrinfo() and other functions to no longer
          misleadingly suggest that they are sandbox-only. Fixes bug 26525;
          bugfix on 0.2.7.1-alpha.
    
      o Minor bugfixes (code safety):
        - Rewrite our assertion macros so that they no longer suppress the
          compiler's -Wparentheses warnings. Fixes bug 27709; bugfix
          on 0.0.6.
    
      o Minor bugfixes (compilation):
        - Initialize a variable unconditionally in aes_new_cipher(), since
          some compilers cannot tell that we always initialize it before
          use. Fixes bug 28413; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (configuration):
        - Refuse to start with relative file paths and RunAsDaemon set
          (regression from the fix for bug 22731). Fixes bug 28298; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (configuration, Onion Services):
        - In rend_service_parse_port_config(), disallow any input to remain
          after address-port pair was parsed. This will catch address and
          port being whitespace-separated by mistake of the user. Fixes bug
          27044; bugfix on 0.2.9.10.
    
      o Minor bugfixes (connection, relay):
        - Avoid a logging a BUG() stacktrace when closing connection held
          open because the write side is rate limited but not the read side.
          Now, the connection read side is simply shut down until Tor is
          able to flush the connection and close it. Fixes bug 27750; bugfix
          on 0.3.4.1-alpha.
    
      o Minor bugfixes (continuous integration, Windows):
        - Stop reinstalling identical packages in our Windows CI. Fixes bug
          27464; bugfix on 0.3.4.1-alpha.
        - Install only the necessary mingw packages during our appveyor
          builds. This change makes the build a little faster, and prevents
          a conflict with a preinstalled mingw openssl that appveyor now
          ships. Fixes bugs 27765 and 27943; bugfix on 0.3.4.2-alpha.
        - Explicitly specify the path to the OpenSSL library and do not
          download OpenSSL from Pacman, but instead use the library that is
          already provided by AppVeyor. Fixes bug 28574; bugfix on master.
        - Manually configure the zstd compiler options, when building using
          mingw on Appveyor Windows CI. The MSYS2 mingw zstd package does
          not come with a pkg-config file. Fixes bug 28454; bugfix
          on 0.3.4.1-alpha.
        - Stop using an external OpenSSL install, and stop installing MSYS2
          packages, when building using mingw on Appveyor Windows CI. Fixes
          bug 28399; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (controller):
        - Consider all routerinfo errors other than "not a server" to be
          transient for the purpose of "GETINFO exit-policy/*" controller
          request. Print stacktrace in the unlikely case of failing to
          recompute routerinfo digest. Fixes bug 27034; bugfix
          on 0.3.4.1-alpha.
    
      o Minor bugfixes (correctness):
        - Fix an unreached code path where we checked the value of
          "hostname" inside send_resolved_hostname_cell(). Previously, we
          used it before checking it; now we check it first. Fixes bug
          28879; bugfix on 0.1.2.7-alpha.
    
      o Minor bugfixes (directory connection shutdown):
        - Avoid a double-close when shutting down a stalled directory
          connection. Fixes bug 26896; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (directory permissions):
        - When a user requests a group-readable DataDirectory, give it to
          them. Previously, when the DataDirectory and the CacheDirectory
          were the same, the default setting (0) for
          CacheDirectoryGroupReadable would override the setting for
          DataDirectoryGroupReadable. Fixes bug 26913; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (HTTP tunnel):
        - Fix a bug warning when closing an HTTP tunnel connection due to an
          HTTP request we couldn't handle. Fixes bug 26470; bugfix
          on 0.3.2.1-alpha.
    
      o Minor bugfixes (ipv6):
        - In addrs_in_same_network_family(), we choose the subnet size based
          on the IP version (IPv4 or IPv6). Previously, we chose a fixed
          subnet size of /16 for both IPv4 and IPv6 addresses. Fixes bug
          15518; bugfix on 0.2.3.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (Linux seccomp2 sandbox):
        - Permit the "shutdown()" system call, which is apparently used by
          OpenSSL under some circumstances. Fixes bug 28183; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (logging):
        - Stop talking about the Named flag in log messages. Clients have
          ignored the Named flag since 0.3.2. Fixes bug 28441; bugfix
          on 0.3.2.1-alpha.
        - As a precaution, do an early return from log_addr_has_changed() if
          Tor is running as client. Also, log a stack trace for debugging as
          this function should only be called when Tor runs as server. Fixes
          bug 26892; bugfix on 0.1.1.9-alpha.
        - Refrain from mentioning bug 21018 in the logs, as it is already
          fixed. Fixes bug 25477; bugfix on 0.2.9.8.
    
      o Minor bugfixes (logging, documentation):
        - When SafeLogging is enabled, scrub IP address in
          channel_tls_process_netinfo_cell(). Also, add a note to manpage
          that scrubbing is not guaranteed on loglevels below Notice. Fixes
          bug 26882; bugfix on 0.2.4.10-alpha.
    
      o Minor bugfixes (memory leaks):
        - Fix a harmless memory leak in libtorrunner.a. Fixes bug 28419;
          bugfix on 0.3.3.1-alpha. Patch from Martin Kepplinger.
        - Fix a small memory leak when calling Tor with --dump-config. Fixes
          bug 27893; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (netflow padding):
        - Ensure circuitmux queues are empty before scheduling or sending
          padding. Fixes bug 25505; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (onion service v2):
        - Log at level "info", not "warning", in the case that we do not
          have a consensus when a .onion request comes in. This can happen
          normally while bootstrapping. Fixes bug 27040; bugfix
          on 0.2.8.2-alpha.
    
      o Minor bugfixes (onion service v3):
        - When deleting an ephemeral onion service (DEL_ONION), do not close
          any rendezvous circuits in order to let the existing client
          connections finish by themselves or closed by the application. The
          HS v2 is doing that already so now we have the same behavior for
          all versions. Fixes bug 28619; bugfix on 0.3.3.1-alpha.
        - Build the service descriptor's signing key certificate before
          uploading, so we always have a fresh one: leaving no chances for
          it to expire service side. Fixes bug 27838; bugfix
          on 0.3.2.1-alpha.
        - Stop dumping a stack trace when trying to connect to an intro
          point without having a descriptor for it. Fixes bug 27774; bugfix
          on 0.3.2.1-alpha.
        - When selecting a v3 rendezvous point, don't only look at the
          protover, but also check whether the curve25519 onion key is
          present. This way we avoid picking a relay that supports the v3
          rendezvous but for which we don't have the microdescriptor. Fixes
          bug 27797; bugfix on 0.3.2.1-alpha.
        - Close all SOCKS request (for the same .onion) if the newly fetched
          descriptor is unusable. Before that, we would close only the first
          one leaving the other hanging and let to time out by themselves.
          Fixes bug 27410; bugfix on 0.3.2.1-alpha.
        - When the onion service directory can't be created or has the wrong
          permissions, do not log a stack trace. Fixes bug 27335; bugfix
          on 0.3.2.1-alpha.
        - When replacing a descriptor in the client cache, make sure to
          close all client introduction circuits for the old descriptor, so
          we don't end up with unusable leftover circuits. Fixes bug 27471;
          bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (OS compatibility):
        - Properly handle configuration changes that move a listener to/from
          wildcard IP address. If the first attempt to bind a socket fails,
          close the old listener and try binding the socket again. Fixes bug
          17873; bugfix on 0.0.8pre-1.
    
      o Minor bugfixes (performance)::
        - Rework node_is_a_configured_bridge() to no longer call
          node_get_all_orports(), which was performing too many memory
          allocations. Fixes bug 27224; bugfix on 0.2.3.9.
    
      o Minor bugfixes (protover):
        - Reject protocol names containing bytes other than alphanumeric
          characters and hyphens ([A-Za-z0-9-]). Fixes bug 27316; bugfix
          on 0.2.9.4-alpha.
    
      o Minor bugfixes (protover, rust):
        - Reject extra commas in version strings. Fixes bug 27197; bugfix
          on 0.3.3.3-alpha.
        - protover_all_supported() would attempt to allocate up to 16GB on
          some inputs, leading to a potential memory DoS. Fixes bug 27206;
          bugfix on 0.3.3.5-rc.
        - Compute protover votes correctly in the rust version of the
          protover code. Previously, the protover rewrite in 24031 allowed
          repeated votes from the same voter for the same protocol version
          to be counted multiple times in protover_compute_vote(). Fixes bug
          27649; bugfix on 0.3.3.5-rc.
        - Reject protover names that contain invalid characters. Fixes bug
          27687; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (relay shutdown, systemd):
        - Notify systemd of ShutdownWaitLength so it can be set to longer
          than systemd's TimeoutStopSec. In Tor's systemd service file, set
          TimeoutSec to 60 seconds to allow Tor some time to shut down.
          Fixes bug 28113; bugfix on 0.2.6.2-alpha.
    
      o Minor bugfixes (relay statistics):
        - Update relay descriptor on bandwidth changes only when the uptime
          is smaller than 24h, in order to reduce the efficiency of guard
          discovery attacks. Fixes bug 24104; bugfix on 0.1.1.6-alpha.
    
      o Minor bugfixes (relay):
        - Consider the fact that we'll be making direct connections to our
          entry and guard nodes when computing the fraction of nodes that
          have their descriptors. Also, if we are using bridges and there is
          at least one bridge with a full descriptor, treat the fraction of
          guards available as 100%. Fixes bug 25886; bugfix on 0.2.4.10-alpha.
          Patch by Neel Chauhan.
        - Update the message logged on relays when DirCache is disabled.
          Since 0.3.3.5-rc, authorities require DirCache (V2Dir) for the
          Guard flag. Fixes bug 24312; bugfix on 0.3.3.5-rc.
    
      o Minor bugfixes (testing):
        - Stop running stem's unit tests as part of "make test-stem", but
          continue to run stem's unit and online tests during "make test-
          stem-full". Fixes bug 28568; bugfix on 0.2.6.3-alpha.
        - Stop leaking memory in an entry guard unit test. Fixes bug 28554;
          bugfix on 0.3.0.1-alpha.
        - Make the hs_service tests use the same time source when creating
          the introduction point and when testing it. Now tests work better
          on very slow systems like ARM or Travis. Fixes bug 27810; bugfix
          on 0.3.2.1-alpha.
        - Revise the "conditionvar_timeout" test so that it succeeds even on
          heavily loaded systems where the test threads are not scheduled
          within 200 msec. Fixes bug 27073; bugfix on 0.2.6.3-alpha.
        - Fix two unit tests to work when HOME environment variable is not
          set. Fixes bug 27096; bugfix on 0.2.8.1-alpha.
        - If a unit test running in a subprocess exits abnormally or with a
          nonzero status code, treat the test as having failed, even if the
          test reported success. Without this fix, memory leaks don't cause
          the tests to fail, even with LeakSanitizer. Fixes bug 27658;
          bugfix on 0.2.2.4-alpha.
        - When logging a version mismatch in our openssl_version tests,
          report the actual offending version strings. Fixes bug 26152;
          bugfix on 0.2.9.1-alpha.
        - Fix forking tests on Windows when there is a space somewhere in
          the path. Fixes bug 26437; bugfix on 0.2.2.4-alpha.
    
      o Minor bugfixes (Windows):
        - Correctly identify Windows 8.1, Windows 10, and Windows Server
          2008 and later from their NT versions. Fixes bug 28096; bugfix on
          0.2.2.34; reported by Keifer Bly.
        - On recent Windows versions, the GetVersionEx() function may report
          an earlier Windows version than the running OS. To avoid user
          confusion, add "[or later]" to Tor's version string on affected
          versions of Windows. Fixes bug 28096; bugfix on 0.2.2.34; reported
          by Keifer Bly.
        - Remove Windows versions that were never supported by the
          GetVersionEx() function. Stop duplicating the latest Windows
          version in get_uname(). Fixes bug 28096; bugfix on 0.2.2.34;
          reported by Keifer Bly.
    
      o Code simplification and refactoring:
        - When parsing a port configuration, make it more obvious to static
          analyzer tools that we always initialize the address. Closes
          ticket 28881.
        - Divide more large Tor source files -- especially ones that span
          multiple areas of functionality -- into smaller parts, including
          onion.c and main.c. Closes ticket 26747.
        - Divide the "routerparse.c" module into separate modules for each
          group of parsed objects. Closes ticket 27924.
        - Move protover_rust.c to the same place protover.c was moved to.
          Closes ticket 27814.
        - Split directory.c into separate pieces for client, server, and
          common functionality. Closes ticket 26744.
        - Split the non-statistics-related parts from the rephist.c and
          geoip.c modules. Closes ticket 27892.
        - Split the router.c file into relay-only and shared components, to
          help with future modularization. Closes ticket 27864.
        - Divide the routerlist.c and dirserv.c modules into smaller parts.
          Closes ticket 27799.
        - 'updateFallbackDirs.py' now ignores the blacklist file, as it's not
          longer needed. Closes ticket 26502.
        - Include paths to header files within Tor are now qualified by
          directory within the top-level src directory.
        - Many structures have been removed from the centralized "or.h"
          header, and moved into their own headers. This will allow us to
          reduce the number of places in the code that rely on each
          structure's contents and layout. Closes ticket 26383.
        - Remove ATTR_NONNULL macro from codebase. Resolves ticket 26527.
        - Remove GetAdaptersAddresses_fn_t. The code that used it was
          removed as part of the 26481 refactor. Closes ticket 27467.
        - Rework Tor SOCKS server code to use Trunnel and benefit from
          autogenerated functions for parsing and generating SOCKS wire
          format. New implementation is cleaner, more maintainable and
          should be less prone to heartbleed-style vulnerabilities.
          Implements a significant fraction of ticket 3569.
        - Split sampled_guards_update_from_consensus() and
          select_entry_guard_for_circuit() into subfunctions. In
          entry_guards_update_primary() unite three smartlist enumerations
          into one and move smartlist comparison code out of the function.
          Closes ticket 21349.
        - Tor now assumes that you have standards-conformant stdint.h and
          inttypes.h headers when compiling. Closes ticket 26626.
        - Unify our bloom filter logic. Previously we had two copies of this
          code: one for routerlist filtering, and one for address set
          calculations. Closes ticket 26510.
        - Use the simpler strcmpstart() helper in
          rend_parse_v2_service_descriptor instead of strncmp(). Closes
          ticket 27630.
        - Utility functions that can perform a DNS lookup are now wholly
          separated from those that can't, in separate headers and C
          modules. Closes ticket 26526.
    
      o Documentation:
        - In the tor-resolve(1) manpage, fix the reference to socks-
          extensions.txt by adding a web URL. Resolves ticket 27853.
        - Mention that we require Python to be 2.7 or newer for some
          integration tests that we ship with Tor. Resolves ticket 27677.
        - Copy paragraph and URL to Tor's code of conduct document from
          CONTRIBUTING to new CODE_OF_CONDUCT file. Resolves ticket 26638.
        - Remove old instructions from INSTALL document. Closes ticket 26588.
        - Warn users that they should not include MyFamily line(s) in their
          torrc when running Tor bridge. Closes ticket 26908.
    
      o Removed features:
        - Tor no longer supports building with the dmalloc library. For
          debugging memory issues, we suggest using gperftools or msan
          instead. Closes ticket 26426.
        - Tor no longer attempts to run on Windows environments without the
          GetAdaptersAddresses() function. This function has existed since
          Windows XP, which is itself already older than we support.
        - Remove Tor2web functionality for version 2 onion services. The
          Tor2webMode and Tor2webRendezvousPoints options are now obsolete.
          (This feature was never shipped in vanilla Tor and it was only
          possible to use this feature by building the support at compile
          time. Tor2webMode is not implemented for version 3 onion services.)
          Closes ticket 26367.
    
      o Testing:
        - Increase logging and tag all log entries with timestamps in
          test_rebind.py. Provides diagnostics for issue 28229.
    
      o Code simplification and refactoring (shared random, dirauth):
        - Change many tor_assert() to use BUG() instead. The idea is to not
          crash a dirauth but rather scream loudly with a stacktrace and let
          it continue run. The shared random subsystem is very resilient and
          if anything wrong happens with it, at worst a non coherent value
          will be put in the vote and discarded by the other authorities.
          Closes ticket 19566.
    
      o Documentation (onion services):
        - Improve HSv3 client authorization by making some options more
          explicit and detailed. Closes ticket 28026. Patch by Mike Tigas.
        - Document in the man page that changing ClientOnionAuthDir value or
          adding a new file in the directory will not work at runtime upon
          sending a HUP if Sandbox 1. Closes ticket 28128.
        - Note in the man page that the only real way to fully revoke an
          onion service v3 client authorization is by restarting the tor
          process. Closes ticket 28275.
    
    
    Changes in version 0.3.4.9 - 2018-11-02
      Tor 0.3.4.9 is the second stable release in its series; it backports
      numerous fixes, including a fix for a bandwidth management bug that
      was causing memory exhaustion on relays. Anyone running an earlier
      version of Tor 0.3.4.9 should upgrade.
    
      o Major bugfixes (compilation, backport from 0.3.5.3-alpha):
        - Fix compilation on ARM (and other less-used CPUs) when compiling
          with OpenSSL before 1.1. Fixes bug 27781; bugfix on 0.3.4.1-alpha.
    
      o Major bugfixes (mainloop, bootstrap, backport from 0.3.5.3-alpha):
        - Make sure Tor bootstraps and works properly if only the
          ControlPort is set. Prior to this fix, Tor would only bootstrap
          when a client port was set (Socks, Trans, NATD, DNS or HTTPTunnel
          port). Fixes bug 27849; bugfix on 0.3.4.1-alpha.
    
      o Major bugfixes (relay, backport from 0.3.5.3-alpha):
        - When our write bandwidth limit is exhausted, stop writing on the
          connection. Previously, we had a typo in the code that would make
          us stop reading instead, leading to relay connections being stuck
          indefinitely and consuming kernel RAM. Fixes bug 28089; bugfix
          on 0.3.4.1-alpha.
    
      o Major bugfixes (restart-in-process, backport from 0.3.5.1-alpha):
        - Fix a use-after-free error that could be caused by passing Tor an
          impossible set of options that would fail during options_act().
          Fixes bug 27708; bugfix on 0.3.3.1-alpha.
    
      o Minor features (continuous integration, backport from 0.3.5.1-alpha):
        - Don't do a distcheck with --disable-module-dirauth in Travis.
          Implements ticket 27252.
        - Only run one online rust build in Travis, to reduce network
          errors. Skip offline rust builds on Travis for Linux gcc, because
          they're redundant. Implements ticket 27252.
        - Skip gcc on OSX in Travis CI, because it's rarely used. Skip a
          duplicate hardening-off build in Travis on Tor 0.2.9. Skip gcc on
          Linux with default settings, because all the non-default builds
          use gcc on Linux. Implements ticket 27252.
    
      o Minor features (continuous integration, backport from 0.3.5.3-alpha):
        - Use the Travis Homebrew addon to install packages on macOS during
          Travis CI. The package list is the same, but the Homebrew addon
          does not do a `brew update` by default. Implements ticket 27738.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the October 9 2018 Maxmind GeoLite2
          Country database. Closes ticket 27991.
    
      o Minor bugfixes (32-bit OSX and iOS, timing, backport from 0.3.5.2-alpha):
        - Fix an integer overflow bug in our optimized 32-bit millisecond-
          difference algorithm for 32-bit Apple platforms. Previously, it
          would overflow when calculating the difference between two times
          more than 47 days apart. Fixes part of bug 27139; bugfix
          on 0.3.4.1-alpha.
        - Improve the precision of our 32-bit millisecond difference
          algorithm for 32-bit Apple platforms. Fixes part of bug 27139;
          bugfix on 0.3.4.1-alpha.
        - Relax the tolerance on the mainloop/update_time_jumps test when
          running on 32-bit Apple platforms. Fixes part of bug 27139; bugfix
          on 0.3.4.1-alpha.
    
      o Minor bugfixes (C correctness, to appear in 0.3.5.4-alpha):
        - Avoid undefined behavior in an end-of-string check when parsing
          the BEGIN line in a directory object. Fixes bug 28202; bugfix
          on 0.2.0.3-alpha.
    
      o Minor bugfixes (CI, appveyor, to appear in 0.3.5.4-alpha):
        - Only install the necessary mingw packages during our appveyor
          builds. This change makes the build a little faster, and prevents
          a conflict with a preinstalled mingw openssl that appveyor now
          ships. Fixes bugs 27943 and 27765; bugfix on 0.3.4.2-alpha.
    
      o Minor bugfixes (code safety, backport from 0.3.5.3-alpha):
        - Rewrite our assertion macros so that they no longer suppress the
          compiler's -Wparentheses warnings. Fixes bug 27709; bugfix
    
      o Minor bugfixes (continuous integration, backport from 0.3.5.1-alpha):
        - Stop reinstalling identical packages in our Windows CI. Fixes bug
          27464; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (directory authority, to appear in 0.3.5.4-alpha):
        - Log additional info when we get a relay that shares an ed25519 ID
          with a different relay, instead making a BUG() warning. Fixes bug
          27800; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (directory connection shutdown, backport from 0.3.5.1-alpha):
        - Avoid a double-close when shutting down a stalled directory
          connection. Fixes bug 26896; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (HTTP tunnel, backport from 0.3.5.1-alpha):
        - Fix a bug warning when closing an HTTP tunnel connection due to an
          HTTP request we couldn't handle. Fixes bug 26470; bugfix
          on 0.3.2.1-alpha.
    
      o Minor bugfixes (netflow padding, backport from 0.3.5.1-alpha):
        - Ensure circuitmux queues are empty before scheduling or sending
          padding. Fixes bug 25505; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (onion service v3, backport from 0.3.5.1-alpha):
        - When the onion service directory can't be created or has the wrong
          permissions, do not log a stack trace. Fixes bug 27335; bugfix
          on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion service v3, backport from 0.3.5.2-alpha):
        - Close all SOCKS request (for the same .onion) if the newly fetched
          descriptor is unusable. Before that, we would close only the first
          one leaving the other hanging and let to time out by themselves.
          Fixes bug 27410; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion service v3, backport from 0.3.5.3-alpha):
        - When selecting a v3 rendezvous point, don't only look at the
          protover, but also check whether the curve25519 onion key is
          present. This way we avoid picking a relay that supports the v3
          rendezvous but for which we don't have the microdescriptor. Fixes
          bug 27797; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (protover, backport from 0.3.5.3-alpha):
        - Reject protocol names containing bytes other than alphanumeric
          characters and hyphens ([A-Za-z0-9-]). Fixes bug 27316; bugfix
          on 0.2.9.4-alpha.
    
      o Minor bugfixes (rust, backport from 0.3.5.1-alpha):
        - Compute protover votes correctly in the rust version of the
          protover code. Previously, the protover rewrite in 24031 allowed
          repeated votes from the same voter for the same protocol version
          to be counted multiple times in protover_compute_vote(). Fixes bug
          27649; bugfix on 0.3.3.5-rc.
        - Reject protover names that contain invalid characters. Fixes bug
          27687; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (rust, backport from 0.3.5.2-alpha):
        - protover_all_supported() would attempt to allocate up to 16GB on
          some inputs, leading to a potential memory DoS. Fixes bug 27206;
          bugfix on 0.3.3.5-rc.
    
      o Minor bugfixes (rust, directory authority, to appear in 0.3.5.4-alpha):
        - Fix an API mismatch in the rust implementation of
          protover_compute_vote(). This bug could have caused crashes on any
          directory authorities running Tor with Rust (which we do not yet
          recommend). Fixes bug 27741; bugfix on 0.3.3.6.
    
      o Minor bugfixes (rust, to appear in 0.3.5.4-alpha):
        - Fix a potential null dereference in protover_all_supported(). Add
          a test for it. Fixes bug 27804; bugfix on 0.3.3.1-alpha.
        - Return a string that can be safely freed by C code, not one
          created by the rust allocator, in protover_all_supported(). Fixes
          bug 27740; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.3.5.1-alpha):
        - If a unit test running in a subprocess exits abnormally or with a
          nonzero status code, treat the test as having failed, even if the
          test reported success. Without this fix, memory leaks don't cause
          the tests to fail, even with LeakSanitizer. Fixes bug 27658;
          bugfix on 0.2.2.4-alpha.
    
      o Minor bugfixes (testing, backport from 0.3.5.3-alpha):
        - Make the hs_service tests use the same time source when creating
          the introduction point and when testing it. Now tests work better
          on very slow systems like ARM or Travis. Fixes bug 27810; bugfix
          on 0.3.2.1-alpha.
    
      o Minor bugfixes (testing, to appear in 0.3.5.4-alpha):
        - Treat backtrace test failures as expected on BSD-derived systems
          (NetBSD, OpenBSD, and macOS/Darwin) until we solve bug 17808.
          (FreeBSD failures have been treated as expected since 18204 in
          0.2.8.) Fixes bug 27948; bugfix on 0.2.5.2-alpha.
    
    
    Changes in version 0.2.9.17 - 2018-09-10
      Tor 0.2.9.17 backports numerous bugfixes from later versions of Tor.
    
      o Minor features (compatibility, backport from 0.3.4.8):
        - Tell OpenSSL to maintain backward compatibility with previous
          RSA1024/DH1024 users in Tor. With OpenSSL 1.1.1-pre6, these
          ciphers are disabled by default. Closes ticket 27344.
    
      o Minor features (continuous integration, backport from 0.3.4.7-rc):
        - Enable macOS builds in our Travis CI configuration. Closes
          ticket 24629.
        - Install libcap-dev and libseccomp2-dev so these optional
          dependencies get tested on Travis CI. Closes ticket 26560.
        - Run asciidoc during Travis CI. Implements ticket 27087.
        - Use ccache in our Travis CI configuration. Closes ticket 26952.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the August 7 2018 Maxmind GeoLite2
          Country database. Closes ticket 27089.
    
      o Minor bugfixes (compilation, backport from 0.3.4.6-rc):
        - When compiling with --enable-openbsd-malloc or --enable-tcmalloc,
          tell the compiler not to include the system malloc implementation.
          Fixes bug 20424; bugfix on 0.2.0.20-rc.
    
      o Minor bugfixes (compilation, backport from 0.3.4.7-rc):
        - Silence a spurious compiler warning on the GetAdaptersAddresses
          function pointer cast. This issue is already fixed by 26481 in
          0.3.5 and later, by removing the lookup and cast. Fixes bug 27465;
          bugfix on 0.2.3.11-alpha.
        - Stop calling SetProcessDEPPolicy() on 64-bit Windows. It is not
          supported, and always fails. Some compilers warn about the
          function pointer cast on 64-bit Windows. Fixes bug 27461; bugfix
          on 0.2.2.23-alpha.
    
      o Minor bugfixes (compilation, windows, backport from 0.3.4.7-rc):
        - Don't link or search for pthreads when building for Windows, even
          if we are using build environment (like mingw) that provides a
          pthreads library. Fixes bug 27081; bugfix on 0.1.0.1-rc.
    
      o Minor bugfixes (continuous integration, backport from 0.3.4.6-rc):
        - Skip a pair of unreliable key generation tests on Windows, until
          the underlying issue in bug 26076 is resolved. Fixes bug 26830 and
          bug 26853; bugfix on 0.2.7.3-rc and 0.3.2.1-alpha respectively.
    
      o Minor bugfixes (continuous integration, backport from 0.3.4.7-rc):
        - Pass the module flags to distcheck configure, and log the flags
          before running configure. (Backported to 0.2.9 and later as a
          precaution.) Fixes bug 27088; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (continuous integration, backport from 0.3.4.8):
        - When a Travis build fails, and showing a log fails, keep trying to
          show the other logs. Fixes bug 27453; bugfix on 0.3.4.7-rc.
        - When we use echo in Travis, don't pass a --flag as the first
          argument. Fixes bug 27418; bugfix on 0.3.4.7-rc.
    
      o Minor bugfixes (directory authority, backport from 0.3.4.6-rc):
        - When voting for recommended versions, make sure that all of the
          versions are well-formed and parsable. Fixes bug 26485; bugfix
          on 0.1.1.6-alpha.
    
      o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.4.7-rc):
        - Fix a bug in out sandboxing rules for the openat() syscall.
          Previously, no openat() call would be permitted, which would break
          filesystem operations on recent glibc versions. Fixes bug 25440;
          bugfix on 0.2.9.15. Diagnosis and patch from Daniel Pinto.
    
      o Minor bugfixes (onion services, backport from 0.3.4.8):
        - Silence a spurious compiler warning in
          rend_client_send_introduction(). Fixes bug 27463; bugfix
          on 0.1.1.2-alpha.
    
      o Minor bugfixes (single onion services, Tor2web, backport from 0.3.4.6-rc):
        - Log a protocol warning when single onion services or Tor2web clients
          fail to authenticate direct connections to relays.
          Fixes bug 26924; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.3.4.6-rc):
        - Disable core dumps in test_bt.sh, to avoid failures in "make
          distcheck". Fixes bug 26787; bugfix on 0.2.5.2-alpha.
    
      o Minor bugfixes (testing, chutney, backport from 0.3.4.8):
        - Before running make test-network-all, delete old logs and test
          result files, to avoid spurious failures. Fixes bug 27295; bugfix
          on 0.2.7.3-rc.
    
      o Minor bugfixes (testing, openssl compatibility, backport from 0.3.4.7-rc):
        - Our "tortls/cert_matches_key" unit test no longer relies on
          OpenSSL internals. Previously, it relied on unsupported OpenSSL
          behavior in a way that caused it to crash with OpenSSL 1.0.2p.
          Fixes bug 27226; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (Windows, compilation, backport from 0.3.4.7-rc):
        - Silence a compilation warning on MSVC 2017 and clang-cl. Fixes bug
          27185; bugfix on 0.2.2.2-alpha.
    
    
    Changes in version 0.3.2.12 - 2018-09-10
      Tor 0.3.2.12 backport numerous fixes from later versions of Tor.
    
      o Minor features (compatibility, backport from 0.3.4.8):
        - Tell OpenSSL to maintain backward compatibility with previous
          RSA1024/DH1024 users in Tor. With OpenSSL 1.1.1-pre6, these
          ciphers are disabled by default. Closes ticket 27344.
    
      o Minor features (continuous integration, backport from 0.3.4.7-rc):
        - Enable macOS builds in our Travis CI configuration. Closes
          ticket 24629.
        - Install libcap-dev and libseccomp2-dev so these optional
          dependencies get tested on Travis CI. Closes ticket 26560.
        - Run asciidoc during Travis CI. Implements ticket 27087.
        - Use ccache in our Travis CI configuration. Closes ticket 26952.
    
      o Minor features (continuous integration, rust, backport from 0.3.4.7-rc):
        - Use cargo cache in our Travis CI configuration. Closes
          ticket 26952.
    
      o Minor features (controller, backport from 0.3.4.6-rc):
        - The control port now exposes the list of HTTPTunnelPorts and
          ExtOrPorts via GETINFO net/listeners/httptunnel and
          net/listeners/extor respectively. Closes ticket 26647.
    
      o Minor features (directory authorities, backport from 0.3.4.7-rc):
        - Authorities no longer vote to make the subprotocol version
          "LinkAuth=1" a requirement: it is unsupportable with NSS, and
          hasn't been needed since Tor 0.3.0.1-alpha. Closes ticket 27286.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the August 7 2018 Maxmind GeoLite2
          Country database. Closes ticket 27089.
    
      o Minor bugfixes (compilation, backport from 0.3.4.6-rc):
        - When compiling with --enable-openbsd-malloc or --enable-tcmalloc,
          tell the compiler not to include the system malloc implementation.
          Fixes bug 20424; bugfix on 0.2.0.20-rc.
        - Don't try to use a pragma to temporarily disable the
          -Wunused-const-variable warning if the compiler doesn't support
          it. Fixes bug 26785; bugfix on 0.3.2.11.
    
      o Minor bugfixes (compilation, backport from 0.3.4.7-rc):
        - Silence a spurious compiler warning on the GetAdaptersAddresses
          function pointer cast. This issue is already fixed by 26481 in
          0.3.5 and later, by removing the lookup and cast. Fixes bug 27465;
          bugfix on 0.2.3.11-alpha.
        - Stop calling SetProcessDEPPolicy() on 64-bit Windows. It is not
          supported, and always fails. Some compilers warn about the
          function pointer cast on 64-bit Windows. Fixes bug 27461; bugfix
          on 0.2.2.23-alpha.
    
      o Minor bugfixes (compilation, windows, backport from 0.3.4.7-rc):
        - Don't link or search for pthreads when building for Windows, even
          if we are using build environment (like mingw) that provides a
          pthreads library. Fixes bug 27081; bugfix on 0.1.0.1-rc.
    
      o Minor bugfixes (continuous integration, backport from 0.3.4.6-rc):
        - Skip a pair of unreliable key generation tests on Windows, until
          the underlying issue in bug 26076 is resolved. Fixes bug 26830 and
          bug 26853; bugfix on 0.2.7.3-rc and 0.3.2.1-alpha respectively.
    
      o Minor bugfixes (continuous integration, backport from 0.3.4.7-rc):
        - Build with zstd on macOS. Fixes bug 27090; bugfix on 0.3.1.5-alpha.
        - Pass the module flags to distcheck configure, and log the flags
          before running configure. (Backported to 0.2.9 and later as a
          precaution.) Fixes bug 27088; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (continuous integration, backport from 0.3.4.8):
        - When a Travis build fails, and showing a log fails, keep trying to
          show the other logs. Fixes bug 27453; bugfix on 0.3.4.7-rc.
        - When we use echo in Travis, don't pass a --flag as the first
          argument. Fixes bug 27418; bugfix on 0.3.4.7-rc.
    
      o Minor bugfixes (directory authority, backport from 0.3.4.6-rc):
        - When voting for recommended versions, make sure that all of the
          versions are well-formed and parsable. Fixes bug 26485; bugfix
          on 0.1.1.6-alpha.
    
      o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.4.7-rc):
        - Fix a bug in out sandboxing rules for the openat() syscall.
          Previously, no openat() call would be permitted, which would break
          filesystem operations on recent glibc versions. Fixes bug 25440;
          bugfix on 0.2.9.15. Diagnosis and patch from Daniel Pinto.
    
      o Minor bugfixes (logging, backport from 0.3.4.6-rc):
        - Improve the log message when connection initiators fail to
          authenticate direct connections to relays. Fixes bug 26927; bugfix
          on 0.3.0.1-alpha.
    
      o Minor bugfixes (onion services, backport from 0.3.4.7-rc):
        - Fix bug that causes services to not ever rotate their descriptors
          if they were getting SIGHUPed often. Fixes bug 26932; bugfix
          on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion services, backport from 0.3.4.8):
        - Silence a spurious compiler warning in
          rend_client_send_introduction(). Fixes bug 27463; bugfix
          on 0.1.1.2-alpha.
    
      o Minor bugfixes (rust, backport from 0.3.4.7-rc):
        - Backport test_rust.sh from master. Fixes bug 26497; bugfix
          on 0.3.1.5-alpha.
        - Consistently use ../../.. as a fallback for $abs_top_srcdir in
          test_rust.sh. Fixes bug 27093; bugfix on 0.3.4.3-alpha.
        - Stop setting $CARGO_HOME. cargo will use the user's $CARGO_HOME, or
          $HOME/.cargo by default. Fixes bug 26497; bugfix on 0.3.1.5-alpha.
    
      o Minor bugfixes (single onion services, Tor2web, backport from 0.3.4.6-rc):
        - Log a protocol warning when single onion services or Tor2web clients
          fail to authenticate direct connections to relays.
          Fixes bug 26924; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.3.4.6-rc):
        - Disable core dumps in test_bt.sh, to avoid failures in "make
          distcheck". Fixes bug 26787; bugfix on 0.2.5.2-alpha.
    
      o Minor bugfixes (testing, chutney, backport from 0.3.4.8):
        - When running make test-network-all, use the mixed+hs-v2 network.
          (A previous fix to chutney removed v3 onion services from the
          mixed+hs-v23 network, so seeing "mixed+hs-v23" in tests is
          confusing.) Fixes bug 27345; bugfix on 0.3.2.1-alpha.
        - Before running make test-network-all, delete old logs and test
          result files, to avoid spurious failures. Fixes bug 27295; bugfix
          on 0.2.7.3-rc.
    
      o Minor bugfixes (testing, openssl compatibility):
        - Our "tortls/cert_matches_key" unit test no longer relies on OpenSSL
          internals.  Previously, it relied on unsupported OpenSSL behavior in
          a way that caused it to crash with OpenSSL 1.0.2p. Fixes bug 27226;
          bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (testing, openssl compatibility, backport from 0.3.4.7-rc):
        - Our "tortls/cert_matches_key" unit test no longer relies on
          OpenSSL internals. Previously, it relied on unsupported OpenSSL
          behavior in a way that caused it to crash with OpenSSL 1.0.2p.
          Fixes bug 27226; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (Windows, compilation, backport from 0.3.4.7-rc):
        - Silence a compilation warning on MSVC 2017 and clang-cl. Fixes bug
          27185; bugfix on 0.2.2.2-alpha.
    
    
    Changes in version 0.3.3.10 - 2018-09-10
      Tor 0.3.3.10 backports numerous fixes from later versions of Tor.
    
      o Minor features (bug workaround, backport from 0.3.4.7-rc):
        - Compile correctly on systems that provide the C11 stdatomic.h
          header, but where C11 atomic functions don't actually compile.
          Closes ticket 26779; workaround for Debian issue 903709.
    
      o Minor features (compatibility, backport from 0.3.4.8):
        - Tell OpenSSL to maintain backward compatibility with previous
          RSA1024/DH1024 users in Tor. With OpenSSL 1.1.1-pre6, these
          ciphers are disabled by default. Closes ticket 27344.
    
      o Minor features (continuous integration, backport from 0.3.4.7-rc):
        - Backport Travis rust distcheck to 0.3.3. Closes ticket 24629.
        - Enable macOS builds in our Travis CI configuration. Closes
          ticket 24629.
        - Install libcap-dev and libseccomp2-dev so these optional
          dependencies get tested on Travis CI. Closes ticket 26560.
        - Run asciidoc during Travis CI. Implements ticket 27087.
        - Use ccache in our Travis CI configuration. Closes ticket 26952.
    
      o Minor features (continuous integration, rust, backport from 0.3.4.7-rc):
        - Use cargo cache in our Travis CI configuration. Closes
          ticket 26952.
    
      o Minor features (controller, backport from 0.3.4.6-rc):
        - The control port now exposes the list of HTTPTunnelPorts and
          ExtOrPorts via GETINFO net/listeners/httptunnel and
          net/listeners/extor respectively. Closes ticket 26647.
    
      o Minor features (directory authorities, backport from 0.3.4.7-rc):
        - Authorities no longer vote to make the subprotocol version
          "LinkAuth=1" a requirement: it is unsupportable with NSS, and
          hasn't been needed since Tor 0.3.0.1-alpha. Closes ticket 27286.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the August 7 2018 Maxmind GeoLite2
          Country database. Closes ticket 27089.
    
      o Minor bugfixes (compilation, backport from 0.3.4.6-rc):
        - When compiling with --enable-openbsd-malloc or --enable-tcmalloc,
          tell the compiler not to include the system malloc implementation.
          Fixes bug 20424; bugfix on 0.2.0.20-rc.
        - Don't try to use a pragma to temporarily disable the
          -Wunused-const-variable warning if the compiler doesn't support
          it. Fixes bug 26785; bugfix on 0.3.2.11.
    
      o Minor bugfixes (compilation, backport from 0.3.4.7-rc):
        - Silence a spurious compiler warning on the GetAdaptersAddresses
          function pointer cast. This issue is already fixed by 26481 in
          0.3.5 and later, by removing the lookup and cast. Fixes bug 27465;
          bugfix on 0.2.3.11-alpha.
        - Stop calling SetProcessDEPPolicy() on 64-bit Windows. It is not
          supported, and always fails. Some compilers warn about the
          function pointer cast on 64-bit Windows. Fixes bug 27461; bugfix
          on 0.2.2.23-alpha.
    
      o Minor bugfixes (compilation, windows, backport from 0.3.4.7-rc):
        - Don't link or search for pthreads when building for Windows, even
          if we are using build environment (like mingw) that provides a
          pthreads library. Fixes bug 27081; bugfix on 0.1.0.1-rc.
    
      o Minor bugfixes (continuous integration, backport from 0.3.4.6-rc):
        - Skip a pair of unreliable key generation tests on Windows, until
          the underlying issue in bug 26076 is resolved. Fixes bug 26830 and
          bug 26853; bugfix on 0.2.7.3-rc and 0.3.2.1-alpha respectively.
    
      o Minor bugfixes (continuous integration, backport from 0.3.4.7-rc):
        - Build with zstd on macOS. Fixes bug 27090; bugfix on 0.3.1.5-alpha.
        - Pass the module flags to distcheck configure, and log the flags
          before running configure. (Backported to 0.2.9 and later as a
          precaution.) Fixes bug 27088; bugfix on 0.3.4.1-alpha.
    
      o Minor bugfixes (continuous integration, backport from 0.3.4.8):
        - When a Travis build fails, and showing a log fails, keep trying to
          show the other logs. Fixes bug 27453; bugfix on 0.3.4.7-rc.
        - When we use echo in Travis, don't pass a --flag as the first
          argument. Fixes bug 27418; bugfix on 0.3.4.7-rc.
    
      o Minor bugfixes (directory authority, backport from 0.3.4.6-rc):
        - When voting for recommended versions, make sure that all of the
          versions are well-formed and parsable. Fixes bug 26485; bugfix
          on 0.1.1.6-alpha.
    
      o Minor bugfixes (in-process restart, backport from 0.3.4.7-rc):
        - Always call tor_free_all() when leaving tor_run_main(). When we
          did not, restarting tor in-process would cause an assertion
          failure. Fixes bug 26948; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.4.7-rc):
        - Fix a bug in our sandboxing rules for the openat() syscall.
          Previously, no openat() call would be permitted, which would break
          filesystem operations on recent glibc versions. Fixes bug 25440;
          bugfix on 0.2.9.15. Diagnosis and patch from Daniel Pinto.
    
      o Minor bugfixes (logging, backport from 0.3.4.6-rc):
        - Improve the log message when connection initiators fail to
          authenticate direct connections to relays. Fixes bug 26927; bugfix
          on 0.3.0.1-alpha.
    
      o Minor bugfixes (onion services, backport from 0.3.4.7-rc):
        - Fix bug that causes services to not ever rotate their descriptors
          if they were getting SIGHUPed often. Fixes bug 26932; bugfix
          on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion services, backport from 0.3.4.8):
        - Silence a spurious compiler warning in
          rend_client_send_introduction(). Fixes bug 27463; bugfix
          on 0.1.1.2-alpha.
    
      o Minor bugfixes (portability, backport from 0.3.4.6-rc):
        - Work around two different bugs in the OS X 10.10 and later SDKs
          that would prevent us from successfully targeting earlier versions
          of OS X. Fixes bug 26876; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (portability, backport from 0.3.4.7-rc):
        - Fix compilation of the unit tests on GNU/Hurd, which does not
          define PATH_MAX. Fixes bug 26873; bugfix on 0.3.3.1-alpha. Patch
          from "paulusASol".
    
      o Minor bugfixes (rust, backport from 0.3.4.7-rc):
        - Backport test_rust.sh from master. Fixes bug 26497; bugfix
          on 0.3.1.5-alpha.
        - Consistently use ../../.. as a fallback for $abs_top_srcdir in
          test_rust.sh. Fixes bug 27093; bugfix on 0.3.4.3-alpha.
        - Protover parsing was accepting the presence of whitespace in
          version strings, which the C implementation would choke on, e.g.
          "Desc=1\t,2". Fixes bug 27177; bugfix on 0.3.3.5-rc.
        - Protover parsing was ignoring a 2nd hyphen and everything after
          it, accepting entries like "Link=1-5-foo". Fixes bug 27164; bugfix
          on 0.3.3.1-alpha.
        - Stop setting $CARGO_HOME. cargo will use the user's $CARGO_HOME, or
          $HOME/.cargo by default. Fixes bug 26497; bugfix on 0.3.1.5-alpha.
        - cd to ${abs_top_builddir}/src/rust before running cargo in
          src/test/test_rust.sh. This makes the working directory consistent
          between builds and tests. Fixes bug 26497; bugfix on 0.3.3.2-alpha.
    
      o Minor bugfixes (single onion services, Tor2web, backport from 0.3.4.6-rc):
        - Log a protocol warning when single onion services or Tor2web clients
          fail to authenticate direct connections to relays.
          Fixes bug 26924; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.3.4.6-rc):
        - Disable core dumps in test_bt.sh, to avoid failures in "make
          distcheck". Fixes bug 26787; bugfix on 0.2.5.2-alpha.
    
      o Minor bugfixes (testing, chutney, backport from 0.3.4.8):
        - When running make test-network-all, use the mixed+hs-v2 network.
          (A previous fix to chutney removed v3 onion services from the
          mixed+hs-v23 network, so seeing "mixed+hs-v23" in tests is
          confusing.) Fixes bug 27345; bugfix on 0.3.2.1-alpha.
        - Before running make test-network-all, delete old logs and test
          result files, to avoid spurious failures. Fixes bug 27295; bugfix
          on 0.2.7.3-rc.
    
      o Minor bugfixes (testing, openssl compatibility, backport from 0.3.4.7-rc):
        - Our "tortls/cert_matches_key" unit test no longer relies on
          OpenSSL internals. Previously, it relied on unsupported OpenSSL
          behavior in a way that caused it to crash with OpenSSL 1.0.2p.
          Fixes bug 27226; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (v3 onion services, backport from 0.3.4.6-rc):
        - Stop sending ed25519 link specifiers in v3 onion service introduce
          cells and descriptors, when the rendezvous or introduction point
          doesn't support ed25519 link authentication. Fixes bug 26627;
          bugfix on 0.3.2.4-alpha.
    
      o Minor bugfixes (Windows, compilation, backport from 0.3.4.7-rc):
        - Silence a compilation warning on MSVC 2017 and clang-cl. Fixes bug
          27185; bugfix on 0.2.2.2-alpha.
    
    
    Changes in version 0.3.4.8 - 2018-09-10
      Tor 0.3.4.8 is the first stable release in its series; it includes
      compilation and portability fixes.
    
      The Tor 0.3.4 series includes improvements for running Tor in
      low-power and embedded environments, which should help performance in
      general. We've begun work on better modularity, and included preliminary
      changes on the directory authority side to accommodate a new bandwidth
      measurement system.  We've also integrated more continuous-integration
      systems into our development process, and made corresponding changes to
      Tor's testing infrastructure.  Finally, we've continued to refine
      our anti-denial-of-service code.
    
      Below are the changes since 0.3.3.9. For a list of only the changes
      since 0.3.4.7-rc, see the ChangeLog file.
    
      o New system requirements:
        - Tor no longer tries to support old operating systems without
          mmap() or some local equivalent. Apparently, compilation on such
          systems has been broken for some time, without anybody noticing or
          complaining. Closes ticket 25398.
    
      o Major features (directory authority, modularization):
        - The directory authority subsystem has been modularized. The code
          is now located in src/or/dirauth/, and is compiled in by default.
          To disable the module, the configure option
          --disable-module-dirauth has been added. This module may be
          disabled by default in some future release. Closes ticket 25610.
    
      o Major features (main loop, CPU usage):
        - When Tor is disabled (via DisableNetwork or via hibernation), it
          no longer needs to run any per-second events. This change should
          make it easier for mobile applications to disable Tor while the
          device is sleeping, or Tor is not running. Closes ticket 26063.
        - Tor no longer enables all of its periodic events by default.
          Previously, Tor would enable all possible main loop events,
          regardless of whether it needed them. Furthermore, many of these
          events are now disabled when Tor is hibernating or DisableNetwork
          is set. This is a big step towards reducing client CPU usage by
          reducing the amount of wake-ups the daemon does. Closes tickets
          25376 and 25762.
        - The bandwidth-limitation logic has been refactored so that
          bandwidth calculations are performed on-demand, rather than every
          TokenBucketRefillInterval milliseconds. This change should improve
          the granularity of our bandwidth calculations, and limit the
          number of times that the Tor process needs to wake up when it is
          idle. Closes ticket 25373.
        - Move responsibility for many operations from a once-per-second
          callback to a callback that is only scheduled as needed. Moving
          this functionality has allowed us to disable the callback when
          Tor's network is disabled. Once enough items are removed from our
          once-per-second callback, we can eliminate it entirely to conserve
          CPU when idle. The functionality removed includes: closing
          connections, circuits, and channels (ticket 25932); consensus
          voting (25937); flushing log callbacks (25951); honoring delayed
          SIGNEWNYM requests (25949); rescanning the consensus cache
          (25931); saving the state file to disk (25948); warning relay
          operators about unreachable ports (25952); and keeping track of
          Tor's uptime (26009).
    
      o Minor features (accounting):
        - When Tor becomes dormant, it now uses a scheduled event to wake up
          at the right time. Previously, we would use the per-second timer
          to check whether to wake up, but we no longer have any per-second
          timers enabled when the network is disabled. Closes ticket 26064.
    
      o Minor features (bug workaround):
        - Compile correctly on systems that provide the C11 stdatomic.h
          header, but where C11 atomic functions don't actually compile.
          Closes ticket 26779; workaround for Debian issue 903709.
    
      o Minor features (code quality):
        - Add optional spell-checking for the Tor codebase, using the
          "misspell" program. To use this feature, run "make check-typos".
          Closes ticket 25024.
    
      o Minor features (compatibility):
        - Tell OpenSSL to maintain backward compatibility with previous
          RSA1024/DH1024 users in Tor. With OpenSSL 1.1.1-pre6, these
          ciphers are disabled by default. Closes ticket 27344.
        - Tor now detects versions of OpenSSL 1.1.0 and later compiled with
          the no-deprecated option, and builds correctly with them. Closes
          tickets 19429, 19981, and 25353.
    
      o Minor features (compilation):
        - When compiling with --enable-openbsd-malloc or --enable-tcmalloc,
          tell the compiler not to include the system malloc implementation.
          Fixes bug 20424; bugfix on 0.2.0.20-rc.
        - Don't try to use a pragma to temporarily disable the
          -Wunused-const-variable warning if the compiler doesn't support
          it. Fixes bug 26785; bugfix on 0.3.2.11.
        - When building Tor, prefer to use Python 3 over Python 2, and more
          recent (contemplated) versions over older ones. Closes
          ticket 26372.
    
      o Minor features (compression, zstd):
        - When running with zstd, Tor now considers using advanced functions
          that the zstd maintainers have labeled as potentially unstable. To
          prevent breakage, Tor will only use this functionality when the
          runtime version of the zstd library matches the version with which
          Tor was compiled. Closes ticket 25162.
    
      o Minor features (configuration):
        - The "DownloadSchedule" options have been renamed to end with
          "DownloadInitialDelay". The old names are still allowed, but will
          produce a warning. Comma-separated lists are still permitted for
          these options, but all values after the first are ignored (as they
          have been since 0.2.9). Closes ticket 23354.
    
      o Minor features (continuous integration):
        - Log the compiler path and version during Appveyor builds.
          Implements ticket 27449.
        - Show config.log and test-suite.log after failed Appveyor builds.
          Also upload the zipped full logs as a build artifact. Implements
          ticket 27430.
        - Backport Travis rust distcheck to 0.3.3. Closes ticket 24629.
        - Enable macOS builds in our Travis CI configuration. Closes
          ticket 24629.
        - Install libcap-dev and libseccomp2-dev so these optional
          dependencies get tested on Travis CI. Closes ticket 26560.
        - Only post Appveyor IRC notifications when the build fails.
          Implements ticket 27275.
        - Run asciidoc during Travis CI. Implements ticket 27087.
        - Use ccache in our Travis CI configuration. Closes ticket 26952.
        - Add the necessary configuration files for continuous integration
          testing on Windows, via the Appveyor platform. Closes ticket
          25549. Patches from Marcin Cieślak and Isis Lovecruft.
    
      o Minor features (continuous integration, rust):
        - Use cargo cache in our Travis CI configuration. Closes
          ticket 26952.
    
      o Minor features (control port):
        - Introduce GETINFO "current-time/{local,utc}" to return the local
          and UTC times respectively in ISO format. This helps a controller
          like Tor Browser detect a time-related error. Closes ticket 25511.
          Patch by Neel Chauhan.
        - Introduce new fields to the CIRC_BW event. There are two new
          fields in each of the read and written directions. The DELIVERED
          fields report the total valid data on the circuit, as measured by
          the payload sizes of verified and error-checked relay command
          cells. The OVERHEAD fields report the total unused bytes in each
          of these cells. Closes ticket 25903.
    
      o Minor features (controller):
        - The control port now exposes the list of HTTPTunnelPorts and
          ExtOrPorts via GETINFO net/listeners/httptunnel and
          net/listeners/extor respectively. Closes ticket 26647.
    
      o Minor features (directory authorities):
        - Stop warning about incomplete bw lines before the first complete
          bw line has been found, so that additional header lines can be
          ignored. Fixes bug 25960; bugfix on 0.2.2.1-alpha
        - Authorities no longer vote to make the subprotocol version
          "LinkAuth=1" a requirement: it is unsupportable with NSS, and
          hasn't been needed since Tor 0.3.0.1-alpha. Closes ticket 27286.
    
      o Minor features (directory authority):
        - Directory authorities now open their key-pinning files as O_SYNC,
          to limit their chances of accidentally writing partial lines.
          Closes ticket 23909.
    
      o Minor features (directory authority, forward compatibility):
        - Make the lines of the measured bandwidth file able to contain
          their entries in any order. Previously, the node_id entry needed
          to come first. Closes ticket 26004.
    
      o Minor features (entry guards):
        - Introduce a new torrc option NumPrimaryGuards for controlling the
          number of primary guards. Closes ticket 25843.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the August 7 2018 Maxmind GeoLite2
          Country database. Closes ticket 27089.
    
      o Minor features (performance):
        - Avoid a needless call to malloc() when processing an incoming
          relay cell. Closes ticket 24914.
        - Make our timing-wheel code run a tiny bit faster on 32-bit
          platforms, by preferring 32-bit math to 64-bit. Closes
          ticket 24688.
        - Avoid a needless malloc()/free() pair every time we handle an ntor
          handshake. Closes ticket 25150.
    
      o Minor features (Rust, portability):
        - Rust cross-compilation is now supported. Closes ticket 25895.
    
      o Minor features (testing):
        - Add a unit test for voting_schedule_get_start_of_next_interval().
          Closes ticket 26014, and helps make unit test coverage
          more deterministic.
        - A new unittests module specifically for testing the functions in
          the (new-ish) bridges.c module has been created with new
          unittests, raising the code coverage percentages. Closes 25425.
        - We now have improved testing for addressmap_get_virtual_address()
          function. This should improve our test coverage, and make our test
          coverage more deterministic. Closes ticket 25993.
    
      o Minor features (timekeeping, circuit scheduling):
        - When keeping track of how busy each circuit have been recently on
          a given connection, use coarse-grained monotonic timers rather
          than gettimeofday(). This change should marginally increase
          accuracy and performance. Implements part of ticket 25927.
    
      o Minor features (unit tests):
        - Test complete bandwidth measurements files, and test that
          incomplete bandwidth lines only give warnings when the end of the
          header has not been detected. Fixes bug 25947; bugfix
          on 0.2.2.1-alpha
    
      o Minor bugfixes (bandwidth management):
        - Consider ourselves "low on write bandwidth" if we have exhausted
          our write bandwidth some time in the last second. This was the
          documented behavior before, but the actual behavior was to change
          this value every TokenBucketRefillInterval. Fixes bug 25828;
          bugfix on 0.2.3.5-alpha.
    
      o Minor bugfixes (C correctness):
        - Add a missing lock acquisition in the shutdown code of the control
          subsystem. Fixes bug 25675; bugfix on 0.2.7.3-rc. Found by
          Coverity; this is CID 1433643.
    
      o Minor bugfixes (code style):
        - Fixed multiple includes of transports.h in src/or/connection.c
          Fixes bug 25261; bugfix on 0.2.5.1-alpha.
        - Remove the unused variable n_possible from the function
          channel_get_for_extend(). Fixes bug 25645; bugfix on 0.2.4.4-alpha
    
      o Minor bugfixes (compilation):
        - Silence a spurious compiler warning on the GetAdaptersAddresses
          function pointer cast. This issue is already fixed by 26481 in
          0.3.5 and later, by removing the lookup and cast. Fixes bug 27465;
          bugfix on 0.2.3.11-alpha.
        - Stop calling SetProcessDEPPolicy() on 64-bit Windows. It is not
          supported, and always fails. Some compilers warn about the
          function pointer cast on 64-bit Windows. Fixes bug 27461; bugfix
          on 0.2.2.23-alpha.
        - Fix a compilation warning on some versions of GCC when building
          code that calls routerinfo_get_my_routerinfo() twice, assuming
          that the second call will succeed if the first one did. Fixes bug
          26269; bugfix on 0.2.8.2-alpha.
        - Refrain from compiling unit testing related object files when
          --disable-unittests is set to configure script. Fixes bug 24891;
          bugfix on 0.2.5.1-alpha.
        - The --enable-fatal-warnings flag now affects Rust code as well.
          Closes ticket 26245.
        - Avoid a compiler warning when casting the return value of
          smartlist_len() to double with DEBUG_SMARTLIST enabled. Fixes bug
          26283; bugfix on 0.2.4.10-alpha.
    
      o Minor bugfixes (compilation, windows):
        - Don't link or search for pthreads when building for Windows, even
          if we are using build environment (like mingw) that provides a
          pthreads library. Fixes bug 27081; bugfix on 0.1.0.1-rc.
    
      o Minor bugfixes (continuous integration):
        - Build with zstd on macOS. Fixes bug 27090; bugfix on 0.3.1.5-alpha.
        - Skip a pair of unreliable key generation tests on Windows, until
          the underlying issue in bug 26076 is resolved. Fixes bug 26830 and
          bug 26853; bugfix on 0.2.7.3-rc and 0.3.2.1-alpha respectively.
    
      o Minor bugfixes (control port):
        - Respond with more human-readable error messages to GETINFO exit-
          policy/* requests. Also, let controller know if an error is
          transient (response code 551) or not (response code 552). Fixes
          bug 25852; bugfix on 0.2.8.1-alpha.
        - Parse the "HSADDRESS=" parameter in HSPOST commands properly.
          Previously, it was misparsed and ignored. Fixes bug 26523; bugfix
          on 0.3.3.1-alpha. Patch by "akwizgran".
        - Make CIRC_BW event reflect the total of all data sent on a
          circuit, including padding and dropped cells. Also fix a mis-
          counting bug when STREAM_BW events were enabled. Fixes bug 25400;
          bugfix on 0.2.5.2-alpha.
    
      o Minor bugfixes (correctness, flow control):
        - Upon receiving a stream-level SENDME cell, verify that our window
          has not grown too large. Fixes bug 26214; bugfix on svn
          r54 (pre-0.0.1).
    
      o Minor bugfixes (directory authority):
        - When voting for recommended versions, make sure that all of the
          versions are well-formed and parsable. Fixes bug 26485; bugfix
          on 0.1.1.6-alpha.
    
      o Minor bugfixes (directory client):
        - When unverified-consensus is verified, rename it to cached-
          consenus. Fixes bug 4187; bugfix on 0.2.0.3-alpha.
        - Fixed launching a certificate fetch always during the scheduled
          periodic consensus fetch by fetching only in those cases when
          consensus are waiting for certs. Fixes bug 24740; bugfix
          on 0.2.9.1-alpha.
    
      o Minor bugfixes (error reporting):
        - Improve tolerance for directory authorities with skewed clocks.
          Previously, an authority with a clock more than 60 seconds ahead
          could cause a client with a correct clock to warn that the
          client's clock was behind. Now the clocks of a majority of
          directory authorities have to be ahead of the client before this
          warning will occur. Fixes bug 25756; bugfix on 0.2.2.25-alpha.
    
      o Minor bugfixes (in-process restart):
        - Always call tor_free_all() when leaving tor_run_main(). When we
          did not, restarting tor in-process would cause an assertion
          failure. Fixes bug 26948; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (Linux seccomp2 sandbox):
        - Fix a bug in our sandboxing rules for the openat() syscall.
          Previously, no openat() call would be permitted, which would break
          filesystem operations on recent glibc versions. Fixes bug 25440;
          bugfix on 0.2.9.15. Diagnosis and patch from Daniel Pinto.
    
      o Minor bugfixes (logging):
        - Improve the log message when connection initiators fail to
          authenticate direct connections to relays. Fixes bug 26927; bugfix
          on 0.3.0.1-alpha.
    
      o Minor bugfixes (onion services):
        - Silence a spurious compiler warning in
          rend_client_send_introduction(). Fixes bug 27463; bugfix
          on 0.1.1.2-alpha.
        - Fix bug that causes services to not ever rotate their descriptors
          if they were getting SIGHUPed often. Fixes bug 26932; bugfix
          on 0.3.2.1-alpha.
        - Recompute some consensus information after detecting a clock jump,
          or after transitioning from a non-live consensus to a live
          consensus. We do this to avoid having an outdated state, and
          miscalculating the index for next-generation onion services. Fixes
          bug 24977; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (portability):
        - Fix compilation of the unit tests on GNU/Hurd, which does not
          define PATH_MAX. Fixes bug 26873; bugfix on 0.3.3.1-alpha. Patch
          from "paulusASol".
        - Work around two different bugs in the OS X 10.10 and later SDKs
          that would prevent us from successfully targeting earlier versions
          of OS X. Fixes bug 26876; bugfix on 0.3.3.1-alpha.
        - Do not align mmap length, as it is not required by POSIX, and the
          getpagesize function is deprecated. Fixes bug 25399; bugfix
          on 0.1.1.23.
    
      o Minor bugfixes (portability, FreeBSD):
        - In have_enough_mem_for_dircache(), the variable DIRCACHE_MIN_MEM_MB
          does not stringify on FreeBSD, so we switch to tor_asprintf().
          Fixes bug 20887; bugfix on 0.2.8.1-alpha. Patch by Neel Chauhan.
    
      o Minor bugfixes (relay statistics):
        - When a relay is collecting internal statistics about how many
          create cell requests it has seen of each type, accurately count
          the requests from relays that temporarily fall out of the
          consensus. (To be extra conservative, we were already ignoring
          requests from clients in our counts, and we continue ignoring them
          here.) Fixes bug 24910; bugfix on 0.2.4.17-rc.
    
      o Minor bugfixes (rust):
        - Backport test_rust.sh from master. Fixes bug 26497; bugfix
          on 0.3.1.5-alpha.
        - Protover parsing was accepting the presence of whitespace in
          version strings, which the C implementation would choke on, e.g.
          "Desc=1\t,2". Fixes bug 27177; bugfix on 0.3.3.5-rc.
        - Protover parsing was ignoring a 2nd hyphen and everything after
          it, accepting entries like "Link=1-5-foo". Fixes bug 27164; bugfix
          on 0.3.3.1-alpha.
        - Stop setting $CARGO_HOME. cargo will use the user's $CARGO_HOME, or
          $HOME/.cargo by default. Fixes bug 26497; bugfix on 0.3.1.5-alpha.
        - cd to ${abs_top_builddir}/src/rust before running cargo in
          src/test/test_rust.sh. This makes the working directory consistent
          between builds and tests. Fixes bug 26497; bugfix on 0.3.3.2-alpha.
    
      o Minor bugfixes (single onion services, Tor2web):
        - Log a protocol warning when single onion services or Tor2web
          clients fail to authenticate direct connections to relays. Fixes
          bug 26924; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (test coverage tools):
        - Update our "cov-diff" script to handle output from the latest
          version of gcov, and to remove extraneous timestamp information
          from its output. Fixes bugs 26101 and 26102; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (testing):
        - Disable core dumps in test_bt.sh, to avoid failures in "make
          distcheck". Fixes bug 26787; bugfix on 0.2.5.2-alpha.
        - When testing workqueue event-cancellation, make sure that we
          actually cancel an event, and that cancel each event with equal
          probability. (It was previously possible, though extremely
          unlikely, for our event-canceling test not to cancel any events.)
          Fixes bug 26008; bugfix on 0.2.6.3-alpha.
        - Repeat part of the test in test_client_pick_intro() a number of
          times, to give it consistent coverage. Fixes bug 25996; bugfix
          on 0.3.2.1-alpha.
        - Remove randomness from the hs_common/responsible_hsdirs test, so
          that it always takes the same path through the function it tests.
          Fixes bug 25997; bugfix on 0.3.2.1-alpha.
        - Change the behavior of the "channel/outbound" test so that it
          never causes a 10-second rollover for the EWMA circuitmux code.
          Previously, this behavior would happen randomly, and result in
          fluctuating test coverage. Fixes bug 25994; bugfix
          on 0.3.3.1-alpha.
        - Use X509_new() to allocate certificates that will be freed later
          with X509_free(). Previously, some parts of the unit tests had
          used tor_malloc_zero(), which is incorrect, and which caused test
          failures on Windows when they were built with extra hardening.
          Fixes bugs 25943 and 25944; bugfix on 0.2.8.1-alpha. Patch by
          Marcin Cieślak.
        - While running the circuit_timeout test, fix the PRNG to a
          deterministic AES stream, so that the test coverage from this test
          will itself be deterministic. Fixes bug 25995; bugfix
          on 0.2.2.2-alpha.
    
      o Minor bugfixes (testing, bootstrap):
        - When calculating bootstrap progress, check exit policies and the
          exit flag. Previously, Tor would only check the exit flag, which
          caused race conditions in small and fast networks like chutney.
          Fixes bug 27236; bugfix on 0.2.6.3-alpha.
    
      o Minor bugfixes (testing, chutney):
        - When running make test-network-all, use the mixed+hs-v2 network.
          (A previous fix to chutney removed v3 onion services from the
          mixed+hs-v23 network, so seeing "mixed+hs-v23" in tests is
          confusing.) Fixes bug 27345; bugfix on 0.3.2.1-alpha.
        - Before running make test-network-all, delete old logs and test
          result files, to avoid spurious failures. Fixes bug 27295; bugfix
          on 0.2.7.3-rc.
    
      o Minor bugfixes (testing, openssl compatibility):
        - Our "tortls/cert_matches_key" unit test no longer relies on
          OpenSSL internals. Previously, it relied on unsupported OpenSSL
          behavior in a way that caused it to crash with OpenSSL 1.0.2p.
          Fixes bug 27226; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (v3 onion services):
        - Stop sending ed25519 link specifiers in v3 onion service introduce
          cells and descriptors, when the rendezvous or introduction point
          doesn't support ed25519 link authentication. Fixes bug 26627;
          bugfix on 0.3.2.4-alpha.
    
      o Minor bugfixes (vanguards):
        - Allow the last hop in a vanguard circuit to be the same as our
          first, to prevent the adversary from influencing guard node choice
          by choice of last hop. Also prevent the creation of A - B - A
          paths, or A - A paths, which are forbidden by relays. Fixes bug
          25870; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (Windows, compilation):
        - Silence a compilation warning on MSVC 2017 and clang-cl. Fixes bug
          27185; bugfix on 0.2.2.2-alpha.
    
      o Code simplification and refactoring:
        - Remove duplicate code in parse_{c,s}method_line and bootstrap
          their functionalities into a single function. Fixes bug 6236;
          bugfix on 0.2.3.6-alpha.
        - We remove the PortForwarding and PortForwardingHelper options,
          related functions, and the port_forwarding tests. These options
          were used by the now-deprecated Vidalia to help ordinary users
          become Tor relays or bridges. Closes ticket 25409. Patch by
          Neel Chauhan.
        - In order to make the OR and dir checking function in router.c less
          confusing we renamed some functions and
          consider_testing_reachability() has been split into
          router_should_check_reachability() and
          router_do_reachability_checks(). Also we improved the documentation
          in some functions. Closes ticket 18918.
        - Initial work to isolate Libevent usage to a handful of modules in
          our codebase, to simplify our call structure, and so that we can
          more easily change event loops in the future if needed. Closes
          ticket 23750.
        - Introduce a function to call getsockname() and return tor_addr_t,
          to save a little complexity throughout the codebase. Closes
          ticket 18105.
        - Make hsdir_index in node_t a hsdir_index_t rather than a pointer
          as hsdir_index is always present. Also, we move hsdir_index_t into
          or.h. Closes ticket 23094. Patch by Neel Chauhan.
        - Merge functions used for describing nodes and suppress the
          functions that do not allocate memory for the output buffer
          string. NODE_DESC_BUF_LEN constant and format_node_description()
          function cannot be used externally from router.c module anymore.
          Closes ticket 25432. Patch by valentecaio.
        - Our main loop has been simplified so that all important operations
          happen inside events. Previously, some operations had to happen
          outside the event loop, to prevent infinite sequences of event
          activations. Closes ticket 25374.
        - Put a SHA1 public key digest in hs_service_intro_point_t, and use
          it in register_intro_circ() and service_intro_point_new(). This
          prevents the digest from being re-calculated each time. Closes
          ticket 23107. Patch by Neel Chauhan.
        - Refactor token-bucket implementations to use a common backend.
          Closes ticket 25766.
        - Remove extern declaration of stats_n_seconds_working variable from
          main, protecting its accesses with get_uptime() and reset_uptime()
          functions. Closes ticket 25081, patch by “valentecaio”.
        - Remove our previous logic for "cached gettimeofday()" -- our
          coarse monotonic timers are fast enough for this purpose, and far
          less error-prone. Implements part of ticket 25927.
        - Remove the return value for fascist_firewall_choose_address_base(),
          and sister functions such as fascist_firewall_choose_address_node()
          and fascist_firewall_choose_address_rs(). Also, while we're here,
          initialize the ap argument as leaving it uninitialized can pose a
          security hazard. Closes ticket 24734. Patch by Neel Chauhan.
        - Rename two fields of connection_t struct. timestamp_lastwritten is
          renamed to timestamp_last_write_allowed and timestamp_lastread is
          renamed to timestamp_last_read_allowed. Closes ticket 24714, patch
          by "valentecaio".
        - Since Tor requires C99, remove our old workaround code for libc
          implementations where free(NULL) doesn't work. Closes ticket 24484.
        - Use our standard rate-limiting code to deal with excessive
          libevent failures, rather than the hand-rolled logic we had
          before. Closes ticket 26016.
        - We remove the return value of node_get_prim_orport() and
          node_get_prim_dirport(), and introduce node_get_prim_orport() in
          node_ipv6_or_preferred() and node_ipv6_dir_preferred() in order to
          check for a null address. Closes ticket 23873. Patch by
          Neel Chauhan.
        - We switch to should_record_bridge_info() in
          geoip_note_client_seen() and options_need_geoip_info() instead of
          accessing the configuration values directly. Fixes bug 25290;
          bugfix on 0.2.1.6-alpha. Patch by Neel Chauhan.
    
      o Deprecated features:
        - As we are not recommending 0.2.5 anymore, we require relays that
          once had an ed25519 key associated with their RSA key to always
          have that key, instead of allowing them to drop back to a version
          that didn't support ed25519. This means they need to use a new RSA
          key if they want to downgrade to an older version of tor without
          ed25519. Closes ticket 20522.
    
      o Removed features:
        - Directory authorities will no longer support voting according to
          any consensus method before consensus method 25. This keeps
          authorities compatible with all authorities running 0.2.9.8 and
          later, and does not break any clients or relays. Implements ticket
          24378 and proposal 290.
        - The PortForwarding and PortForwardingHelper features have been
          removed. The reasoning is, given that implementations of NAT
          traversal protocols within common consumer grade routers are
          frequently buggy, and that the target audience for a NAT punching
          feature is a perhaps less-technically-inclined relay operator,
          when the helper fails to setup traversal the problems are usually
          deep, ugly, and very router specific, making them horrendously
          impossible for technical support to reliable assist with, and thus
          resulting in frustration all around. Unfortunately, relay
          operators who would like to run relays behind NATs will need to
          become more familiar with the port forwarding configurations on
          their local router. Closes 25409.
        - The TestingEnableTbEmptyEvent option has been removed. It was used
          in testing simulations to measure how often connection buckets
          were emptied, in order to improve our scheduling, but it has not
          been actively used in years. Closes ticket 25760.
        - The old "round-robin" circuit multiplexer (circuitmux)
          implementation has been removed, along with a fairly large set of
          code that existed to support it. It has not been the default
          circuitmux since we introduced the "EWMA" circuitmux in 0.2.4.x,
          but it still required an unreasonable amount of memory and CPU.
          Closes ticket 25268.
    
    
    Changes in version 0.3.3.9 - 2018-07-13
      Tor 0.3.3.9 moves to a new bridge authority, meaning people running
      bridge relays should upgrade.
    
      o Directory authority changes:
        - The "Bifroest" bridge authority has been retired; the new bridge
          authority is "Serge", and it is operated by George from the
          TorBSD project. Closes ticket 26771.
    
    
    Changes in version 0.3.2.11 - 2018-07-13
      Tor 0.3.2.11 moves to a new bridge authority, meaning people running
      bridge relays should upgrade. We also take this opportunity to backport
      other minor fixes.
    
      o Directory authority changes:
        - The "Bifroest" bridge authority has been retired; the new bridge
          authority is "Serge", and it is operated by George from the
          TorBSD project. Closes ticket 26771.
    
      o Directory authority changes (backport from 0.3.3.7):
        - Add an IPv6 address for the "dannenberg" directory authority.
          Closes ticket 26343.
    
      o Major bugfixes (directory authorities, backport from 0.3.4.1-alpha):
        - When directory authorities read a zero-byte bandwidth file, they
          would previously log a warning with the contents of an
          uninitialised buffer. They now log a warning about the empty file
          instead. Fixes bug 26007; bugfix on 0.2.2.1-alpha.
    
      o Major bugfixes (onion service, backport from 0.3.4.1-alpha):
        - Correctly detect when onion services get disabled after HUP. Fixes
          bug 25761; bugfix on 0.3.2.1.
    
      o Minor features (sandbox, backport from 0.3.3.4-alpha):
        - Explicitly permit the poll() system call when the Linux
          seccomp2-based sandbox is enabled: apparently, some versions of
          libc use poll() when calling getpwnam(). Closes ticket 25313.
    
      o Minor feature (continuous integration, backport from 0.3.3.5-rc):
        - Update the Travis CI configuration to use the stable Rust channel,
          now that we have decided to require that. Closes ticket 25714.
    
      o Minor features (continuous integration, backport from 0.3.4.1-alpha):
        - Our .travis.yml configuration now includes support for testing the
          results of "make distcheck". (It's not uncommon for "make check"
          to pass but "make distcheck" to fail.) Closes ticket 25814.
        - Our Travis CI configuration now integrates with the Coveralls
          coverage analysis tool. Closes ticket 25818.
    
      o Minor features (relay, diagnostic, backport from 0.3.4.3-alpha):
        - Add several checks to detect whether Tor relays are uploading
          their descriptors without specifying why they regenerated them.
          Diagnostic for ticket 25686.
    
      o Minor features (compilation, backport from 0.3.4.4-rc):
        - When building Tor, prefer to use Python 3 over Python 2, and more
          recent (contemplated) versions over older ones. Closes
          ticket 26372.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the July 3 2018 Maxmind GeoLite2
          Country database. Closes ticket 26674.
    
      o Minor bugfixes (correctness, client, backport from 0.3.4.1-alpha):
        - Upon receiving a malformed connected cell, stop processing the
          cell immediately. Previously we would mark the connection for
          close, but continue processing the cell as if the connection were
          open. Fixes bug 26072; bugfix on 0.2.4.7-alpha.
    
      o Minor bugfixes (Linux seccomp2 sandbox, backport from 0.3.4.1-alpha):
        - Allow the nanosleep() system call, which glibc uses to implement
          sleep() and usleep(). Fixes bug 24969; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (testing, compatibility, backport from 0.3.4.4-rc):
        - When running the hs_ntor_ref.py test, make sure only to pass
          strings (rather than "bytes" objects) to the Python subprocess
          module. Python 3 on Windows seems to require this. Fixes bug
          26535; bugfix on 0.3.1.1-alpha.
        - When running the ntor_ref.py test, make sure only to pass strings
          (rather than "bytes" objects) to the Python subprocess module.
          Python 3 on Windows seems to require this. Fixes bug 26535; bugfix
          on 0.2.5.5-alpha.
    
      o Minor bugfixes (compatibility, openssl, backport from 0.3.4.2-alpha):
        - Work around a change in OpenSSL 1.1.1 where return values that
          would previously indicate "no password" now indicate an empty
          password. Without this workaround, Tor instances running with
          OpenSSL 1.1.1 would accept descriptors that other Tor instances
          would reject. Fixes bug 26116; bugfix on 0.2.5.16.
    
      o Minor bugfixes (documentation, backport from 0.3.3.5-rc):
        - Document that the PerConnBW{Rate,Burst} options will fall back to
          their corresponding consensus parameters only if those parameters
          are set. Previously we had claimed that these values would always
          be set in the consensus. Fixes bug 25296; bugfix on 0.2.2.7-alpha.
    
      o Minor bugfixes (compilation, backport from 0.3.4.4-rc):
        - Fix a compilation warning on some versions of GCC when building
          code that calls routerinfo_get_my_routerinfo() twice, assuming
          that the second call will succeed if the first one did. Fixes bug
          26269; bugfix on 0.2.8.2-alpha.
    
      o Minor bugfixes (client, backport from 0.3.4.1-alpha):
        - Don't consider Tor running as a client if the ControlPort is open,
          but no actual client ports are open. Fixes bug 26062; bugfix
          on 0.2.9.4-alpha.
    
      o Minor bugfixes (hardening, backport from 0.3.4.2-alpha):
        - Prevent a possible out-of-bounds smartlist read in
          protover_compute_vote(). Fixes bug 26196; bugfix on 0.2.9.4-alpha.
    
      o Minor bugfixes (C correctness, backport from 0.3.3.4-alpha):
        - Fix a very unlikely (impossible, we believe) null pointer
          dereference. Fixes bug 25629; bugfix on 0.2.9.15. Found by
          Coverity; this is CID 1430932.
    
      o Minor bugfixes (onion service, backport from 0.3.4.1-alpha):
        - Fix a memory leak when a v3 onion service is configured and gets a
          SIGHUP signal. Fixes bug 25901; bugfix on 0.3.2.1-alpha.
        - When parsing the descriptor signature, look for the token plus an
          extra white-space at the end. This is more correct but also will
          allow us to support new fields that might start with "signature".
          Fixes bug 26069; bugfix on 0.3.0.1-alpha.
    
      o Minor bugfixes (relay, backport from 0.3.4.3-alpha):
        - Relays now correctly block attempts to re-extend to the previous
          relay by Ed25519 identity. Previously they would warn in this
          case, but not actually reject the attempt. Fixes bug 26158; bugfix
          on 0.3.0.1-alpha.
    
      o Minor bugfixes (relay, crash, backport from 0.3.4.1-alpha):
        - Avoid a crash when running with DirPort set but ORPort turned off.
          Fixes a case of bug 23693; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.3.4.2-alpha):
        - Silence unused-const-variable warnings in zstd.h with some GCC
          versions. Fixes bug 26272; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (testing, backport from 0.3.3.4-alpha):
        - Avoid intermittent test failures due to a test that had relied on
          onion service introduction point creation finishing within 5
          seconds of real clock time. Fixes bug 25450; bugfix
          on 0.3.1.3-alpha.
    
      o Minor bugfixes (compilation, backport from 0.3.3.4-alpha):
        - Fix a C99 compliance issue in our configuration script that caused
          compilation issues when compiling Tor with certain versions of
          xtools. Fixes bug 25474; bugfix on 0.3.2.5-alpha.
    
      o Minor bugfixes (memory, correctness, backport from 0.3.4.4-rc):
        - Fix a number of small memory leaks identified by coverity. Fixes
          bug 26467; bugfix on numerous Tor versions.
    
      o Code simplification and refactoring (backport from 0.3.3.5-rc):
        - Move the list of default directory authorities to its own file.
          Closes ticket 24854. Patch by "beastr0".
    
    
    Changes in version 0.2.9.16 - 2018-07-13
      Tor 0.2.9.16 moves to a new bridge authority, meaning people running
      bridge relays should upgrade. We also take this opportunity to backport
      other minor fixes.
    
      o Directory authority changes:
        - The "Bifroest" bridge authority has been retired; the new bridge
          authority is "Serge", and it is operated by George from the
          TorBSD project. Closes ticket 26771.
    
      o Directory authority changes (backport from 0.3.3.7):
        - Add an IPv6 address for the "dannenberg" directory authority.
          Closes ticket 26343.
    
      o Major bugfixes (directory authorities, backport from 0.3.4.1-alpha):
        - When directory authorities read a zero-byte bandwidth file, they
          would previously log a warning with the contents of an
          uninitialised buffer. They now log a warning about the empty file
          instead. Fixes bug 26007; bugfix on 0.2.2.1-alpha.
    
      o Minor features (sandbox, backport from 0.3.3.4-alpha):
        - Explicitly permit the poll() system call when the Linux
          seccomp2-based sandbox is enabled: apparently, some versions of
          libc use poll() when calling getpwnam(). Closes ticket 25313.
    
      o Minor features (continuous integration, backport from 0.3.4.1-alpha):
        - Our .travis.yml configuration now includes support for testing the
          results of "make distcheck". (It's not uncommon for "make check"
          to pass but "make distcheck" to fail.) Closes ticket 25814.
        - Our Travis CI configuration now integrates with the Coveralls
          coverage analysis tool. Closes ticket 25818.
    
      o Minor features (compilation, backport from 0.3.4.4-rc):
        - When building Tor, prefer to use Python 3 over Python 2, and more
          recent (contemplated) versions over older ones. Closes
          ticket 26372.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the July 3 2018 Maxmind GeoLite2
          Country database. Closes ticket 26674.
    
      o Minor bugfixes (correctness, client, backport from 0.3.4.1-alpha):
        - Upon receiving a malformed connected cell, stop processing the
          cell immediately. Previously we would mark the connection for
          close, but continue processing the cell as if the connection were
          open. Fixes bug 26072; bugfix on 0.2.4.7-alpha.
    
      o Minor bugfixes (Linux seccomp2 sandbox, backport from 0.3.4.1-alpha):
        - Allow the nanosleep() system call, which glibc uses to implement
          sleep() and usleep(). Fixes bug 24969; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (testing, compatibility, backport from 0.3.4.4-rc):
        - When running the ntor_ref.py test, make sure only to pass strings
          (rather than "bytes" objects) to the Python subprocess module.
          Python 3 on Windows seems to require this. Fixes bug 26535; bugfix
          on 0.2.5.5-alpha.
    
      o Minor bugfixes (compatibility, openssl, backport from 0.3.4.2-alpha):
        - Work around a change in OpenSSL 1.1.1 where return values that
          would previously indicate "no password" now indicate an empty
          password. Without this workaround, Tor instances running with
          OpenSSL 1.1.1 would accept descriptors that other Tor instances
          would reject. Fixes bug 26116; bugfix on 0.2.5.16.
    
      o Minor bugfixes (compilation, backport from 0.3.4.4-rc):
        - Fix a compilation warning on some versions of GCC when building
          code that calls routerinfo_get_my_routerinfo() twice, assuming
          that the second call will succeed if the first one did. Fixes bug
          26269; bugfix on 0.2.8.2-alpha.
    
      o Minor bugfixes (client, backport from 0.3.4.1-alpha):
        - Don't consider Tor running as a client if the ControlPort is open,
          but no actual client ports are open. Fixes bug 26062; bugfix
          on 0.2.9.4-alpha.
    
      o Minor bugfixes (hardening, backport from 0.3.4.2-alpha):
        - Prevent a possible out-of-bounds smartlist read in
          protover_compute_vote(). Fixes bug 26196; bugfix on 0.2.9.4-alpha.
    
      o Minor bugfixes (C correctness, backport from 0.3.3.4-alpha):
        - Fix a very unlikely (impossible, we believe) null pointer
          dereference. Fixes bug 25629; bugfix on 0.2.9.15. Found by
          Coverity; this is CID 1430932.
    
      o Minor bugfixes (memory, correctness, backport from 0.3.4.4-rc):
        - Fix a number of small memory leaks identified by coverity. Fixes
          bug 26467; bugfix on numerous Tor versions.
    
      o Code simplification and refactoring (backport from 0.3.3.5-rc):
        - Move the list of default directory authorities to its own file.
          Closes ticket 24854. Patch by "beastr0".
    
    
    Changes in version 0.3.3.8 - 2018-07-09
      Tor 0.3.3.8 backports several changes from the 0.3.4.x series, including
      fixes for a memory leak affecting directory authorities.
    
      o Major bugfixes (directory authority, backport from 0.3.4.3-alpha):
        - Stop leaking memory on directory authorities when planning to
          vote. This bug was crashing authorities by exhausting their
          memory. Fixes bug 26435; bugfix on 0.3.3.6.
    
      o Major bugfixes (rust, testing, backport from 0.3.4.3-alpha):
        - Make sure that failing tests in Rust will actually cause the build
          to fail: previously, they were ignored. Fixes bug 26258; bugfix
          on 0.3.3.4-alpha.
    
      o Minor features (compilation, backport from 0.3.4.4-rc):
        - When building Tor, prefer to use Python 3 over Python 2, and more
          recent (contemplated) versions over older ones. Closes
          ticket 26372.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the July 3 2018 Maxmind GeoLite2
          Country database. Closes ticket 26674.
    
      o Minor features (relay, diagnostic, backport from 0.3.4.3-alpha):
        - Add several checks to detect whether Tor relays are uploading
          their descriptors without specifying why they regenerated them.
          Diagnostic for ticket 25686.
    
      o Minor bugfixes (circuit path selection, backport from 0.3.4.1-alpha):
        - Don't count path selection failures as circuit build failures.
          This change should eliminate cases where Tor blames its guard or
          the network for situations like insufficient microdescriptors
          and/or overly restrictive torrc settings. Fixes bug 25705; bugfix
          on 0.3.3.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.3.4.4-rc):
        - Fix a compilation warning on some versions of GCC when building
          code that calls routerinfo_get_my_routerinfo() twice, assuming
          that the second call will succeed if the first one did. Fixes bug
          26269; bugfix on 0.2.8.2-alpha.
    
      o Minor bugfixes (control port, backport from 0.3.4.4-rc):
        - Handle the HSADDRESS= argument to the HSPOST command properly.
          (Previously, this argument was misparsed and thus ignored.) Fixes
          bug 26523; bugfix on 0.3.3.1-alpha. Patch by "akwizgran".
    
      o Minor bugfixes (memory, correctness, backport from 0.3.4.4-rc):
        - Fix a number of small memory leaks identified by coverity. Fixes
          bug 26467; bugfix on numerous Tor versions.
    
      o Minor bugfixes (relay, backport from 0.3.4.3-alpha):
        - Relays now correctly block attempts to re-extend to the previous
          relay by Ed25519 identity. Previously they would warn in this
          case, but not actually reject the attempt. Fixes bug 26158; bugfix
          on 0.3.0.1-alpha.
    
      o Minor bugfixes (restart-in-process, backport from 0.3.4.1-alpha):
        - When shutting down, Tor now clears all the flags in the control.c
          module. This should prevent a bug where authentication cookies are
          not generated on restart. Fixes bug 25512; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (testing, compatibility, backport from 0.3.4.4-rc):
        - When running the hs_ntor_ref.py test, make sure only to pass
          strings (rather than "bytes" objects) to the Python subprocess
          module. Python 3 on Windows seems to require this. Fixes bug
          26535; bugfix on 0.3.1.1-alpha.
        - When running the ntor_ref.py test, make sure only to pass strings
          (rather than "bytes" objects) to the Python subprocess module.
          Python 3 on Windows seems to require this. Fixes bug 26535; bugfix
          on 0.2.5.5-alpha.
    
    
    Changes in version 0.3.3.7 - 2018-06-12
      Tor 0.3.3.7 backports several changes from the 0.3.4.x series, including
      fixes for bugs affecting compatibility and stability.
    
      o Directory authority changes:
        - Add an IPv6 address for the "dannenberg" directory authority.
          Closes ticket 26343.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the June 7 2018 Maxmind GeoLite2
          Country database. Closes ticket 26351.
    
      o Minor bugfixes (compatibility, openssl, backport from 0.3.4.2-alpha):
        - Work around a change in OpenSSL 1.1.1 where return values that
          would previously indicate "no password" now indicate an empty
          password. Without this workaround, Tor instances running with
          OpenSSL 1.1.1 would accept descriptors that other Tor instances
          would reject. Fixes bug 26116; bugfix on 0.2.5.16.
    
      o Minor bugfixes (compilation, backport from 0.3.4.2-alpha):
        - Silence unused-const-variable warnings in zstd.h with some GCC
          versions. Fixes bug 26272; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (controller, backport from 0.3.4.2-alpha):
        - Improve accuracy of the BUILDTIMEOUT_SET control port event's
          TIMEOUT_RATE and CLOSE_RATE fields. (We were previously
          miscounting the total number of circuits for these field values.)
          Fixes bug 26121; bugfix on 0.3.3.1-alpha.
    
      o Minor bugfixes (hardening, backport from 0.3.4.2-alpha):
        - Prevent a possible out-of-bounds smartlist read in
          protover_compute_vote(). Fixes bug 26196; bugfix on 0.2.9.4-alpha.
    
      o Minor bugfixes (path selection, backport from 0.3.4.1-alpha):
        - Only select relays when they have the descriptors we prefer to use
          for them. This change fixes a bug where we could select a relay
          because it had _some_ descriptor, but reject it later with a
          nonfatal assertion error because it didn't have the exact one we
          wanted. Fixes bugs 25691 and 25692; bugfix on 0.3.3.4-alpha.
    
    
    Changes in version 0.3.3.6 - 2018-05-22
      Tor 0.3.3.6 is the first stable release in the 0.3.3 series. It
      backports several important fixes from the 0.3.4.1-alpha.
    
      The Tor 0.3.3 series includes controller support and other
      improvements for v3 onion services, official support for embedding Tor
      within other applications, and our first non-trivial module written in
      the Rust programming language. (Rust is still not enabled by default
      when building Tor.) And as usual, there are numerous other smaller
      bugfixes, features, and improvements.
    
      Below are the changes since 0.3.2.10. For a list of only the changes
      since 0.3.3.5-rc, see the ChangeLog file.
    
      o New system requirements:
        - When built with Rust, Tor now depends on version 0.2.39 of the
          libc crate. Closes tickets 25310 and 25664.
    
      o Major features (embedding):
        - There is now a documented stable API for programs that need to
          embed Tor. See tor_api.h for full documentation and known bugs.
          Closes ticket 23684.
        - Tor now has support for restarting in the same process.
          Controllers that run Tor using the "tor_api.h" interface can now
          restart Tor after Tor has exited. This support is incomplete,
          however: we fixed crash bugs that prevented it from working at
          all, but many bugs probably remain, including a possibility of
          security issues. Implements ticket 24581.
    
      o Major features (IPv6, directory documents):
        - Add consensus method 27, which adds IPv6 ORPorts to the microdesc
          consensus. This information makes it easier for IPv6 clients to
          bootstrap and choose reachable entry guards. Implements
          ticket 23826.
        - Add consensus method 28, which removes IPv6 ORPorts from
          microdescriptors. Now that the consensus contains IPv6 ORPorts,
          they are redundant in microdescs. This change will be used by Tor
          clients on 0.2.8.x and later. (That is to say, with all Tor
          clients that have IPv6 bootstrap and guard support.) Implements
          ticket 23828.
        - Expand the documentation for AuthDirHasIPv6Connectivity when it is
          set by different numbers of authorities. Fixes 23870
          on 0.2.4.1-alpha.
    
      o Major features (onion service v3, control port):
        - The control port now supports commands and events for v3 onion
          services. It is now possible to create ephemeral v3 services using
          ADD_ONION. Additionally, several events (HS_DESC, HS_DESC_CONTENT,
          CIRC and CIRC_MINOR) and commands (GETINFO, HSPOST, ADD_ONION and
          DEL_ONION) have been extended to support v3 onion services. Closes
          ticket 20699; implements proposal 284.
    
      o Major features (onion services):
        - Provide torrc options to pin the second and third hops of onion
          service circuits to a list of nodes. The option HSLayer2Guards
          pins the second hop, and the option HSLayer3Guards pins the third
          hop. These options are for use in conjunction with experiments
          with "vanguards" for preventing guard enumeration attacks. Closes
          ticket 13837.
        - When v3 onion service clients send introduce cells, they now
          include the IPv6 address of the rendezvous point, if it has one.
          Current v3 onion services running 0.3.2 ignore IPv6 addresses, but
          in future Tor versions, IPv6-only v3 single onion services will be
          able to use IPv6 addresses to connect directly to the rendezvous
          point. Closes ticket 23577. Patch by Neel Chauhan.
    
      o Major features (relay):
        - Implement an option, ReducedExitPolicy, to allow an Tor exit relay
          operator to use a more reasonable ("reduced") exit policy, rather
          than the default one. If you want to run an exit node without
          thinking too hard about which ports to allow, this one is for you.
          Closes ticket 13605. Patch from Neel Chauhan.
    
      o Major features (rust, portability, experimental):
        - Tor now ships with an optional implementation of one of its
          smaller modules (protover.c) in the Rust programming language. To
          try it out, install a Rust build environment, and configure Tor
          with "--enable-rust --enable-cargo-online-mode". This should not
          cause any user-visible changes, but should help us gain more
          experience with Rust, and plan future Rust integration work.
          Implementation by Chelsea Komlo. Closes ticket 22840.
    
      o Major bugfixes (directory authorities, security, backport from 0.3.4.1-alpha):
        - When directory authorities read a zero-byte bandwidth file, they
          would previously log a warning with the contents of an
          uninitialised buffer. They now log a warning about the empty file
          instead. Fixes bug 26007; bugfix on 0.2.2.1-alpha.
    
      o Major bugfixes (security, directory authority, denial-of-service):
        - Fix a bug that could have allowed an attacker to force a directory
          authority to use up all its RAM by passing it a maliciously
          crafted protocol versions string. Fixes bug 25517; bugfix on
          0.2.9.4-alpha. This issue is also tracked as TROVE-2018-005.
    
      o Major bugfixes (crash, backport from 0.3.4.1-alpha):
        - Avoid a rare assertion failure in the circuit build timeout code
          if we fail to allow any circuits to actually complete. Fixes bug
          25733; bugfix on 0.2.2.2-alpha.
    
      o Major bugfixes (netflow padding):
        - Stop adding unneeded channel padding right after we finish
          flushing to a connection that has been trying to flush for many
          seconds. Instead, treat all partial or complete flushes as
          activity on the channel, which will defer the time until we need
          to add padding. This fix should resolve confusing and scary log
          messages like "Channel padding timeout scheduled 221453ms in the
          past." Fixes bug 22212; bugfix on 0.3.1.1-alpha.
    
      o Major bugfixes (networking):
        - Tor will no longer reject IPv6 address strings from Tor Browser
          when they are passed as hostnames in SOCKS5 requests. Fixes bug
          25036, bugfix on Tor 0.3.1.2.
    
      o Major bugfixes (onion service, backport from 0.3.4.1-alpha):
        - Correctly detect when onion services get disabled after HUP. Fixes
          bug 25761; bugfix on 0.3.2.1.
    
      o Major bugfixes (performance, load balancing):
        - Directory authorities no longer vote in favor of the Guard flag
          for relays without directory support. Starting in Tor
          0.3.0.1-alpha, clients have been avoiding using such relays in the
          Guard position, leading to increasingly broken load balancing for
          the 5%-or-so of Guards that don't advertise directory support.
          Fixes bug 22310; bugfix on 0.3.0.6.
    
      o Major bugfixes (relay):
        - If we have failed to connect to a relay and received a connection
          refused, timeout, or similar error (at the TCP level), do not try
          that same address/port again for 60 seconds after the failure has
          occurred. Fixes bug 24767; bugfix on 0.0.6.
    
      o Major bugfixes (relay, denial of service, backport from 0.3.4.1-alpha):
        - Impose a limit on circuit cell queue size. The limit can be
          controlled by a consensus parameter. Fixes bug 25226; bugfix
          on 0.2.4.14-alpha.
    
      o Minor features (cleanup):
        - Tor now deletes the CookieAuthFile and ExtORPortCookieAuthFile
          when it stops. Closes ticket 23271.
    
      o Minor features (compatibility, backport from 0.3.4.1-alpha):
        - Avoid some compilation warnings with recent versions of LibreSSL.
          Closes ticket 26006.
    
      o Minor features (config options):
        - Change the way the default value for MaxMemInQueues is calculated.
          We now use 40% of the hardware RAM if the system has 8 GB RAM or
          more. Otherwise we use the former value of 75%. Closes
          ticket 24782.
    
      o Minor features (continuous integration):
        - Update the Travis CI configuration to use the stable Rust channel,
          now that we have decided to require that. Closes ticket 25714.
    
      o Minor features (continuous integration, backport from 0.3.4.1-alpha):
        - Our .travis.yml configuration now includes support for testing the
          results of "make distcheck". (It's not uncommon for "make check"
          to pass but "make distcheck" to fail.) Closes ticket 25814.
        - Our Travis CI configuration now integrates with the Coveralls
          coverage analysis tool. Closes ticket 25818.
    
      o Minor features (defensive programming):
        - Most of the functions in Tor that free objects have been replaced
          with macros that free the objects and set the corresponding
          pointers to NULL. This change should help prevent a large class of
          dangling pointer bugs. Closes ticket 24337.
        - Where possible, the tor_free() macro now only evaluates its input
          once. Part of ticket 24337.
        - Check that microdesc ed25519 ids are non-zero in
          node_get_ed25519_id() before returning them. Implements ticket
          24001, patch by "aruna1234".
    
      o Minor features (directory authority):
        - When directory authorities are unable to add signatures to a
          pending consensus, log the reason why. Closes ticket 24849.
    
      o Minor features (embedding):
        - Tor can now start with a preauthenticated control connection
          created by the process that launched it. This feature is meant for
          use by programs that want to launch and manage a Tor process
          without allowing other programs to manage it as well. For more
          information, see the __OwningControllerFD option documented in
          control-spec.txt. Closes ticket 23900.
        - On most errors that would cause Tor to exit, it now tries to
          return from the tor_main() function, rather than calling the
          system exit() function. Most users won't notice a difference here,
          but it should be significant for programs that run Tor inside a
          separate thread: they should now be able to survive Tor's exit
          conditions rather than having Tor shut down the entire process.
          Closes ticket 23848.
        - Applications that want to embed Tor can now tell Tor not to
          register any of its own POSIX signal handlers, using the
          __DisableSignalHandlers option. Closes ticket 24588.
    
      o Minor features (fallback directory list):
        - Avoid selecting fallbacks that change their IP addresses too
          often. Select more fallbacks by ignoring the Guard flag, and
          allowing lower cutoffs for the Running and V2Dir flags. Also allow
          a lower bandwidth, and a higher number of fallbacks per operator
          (5% of the list). Implements ticket 24785.
        - Update the fallback whitelist and blacklist based on opt-ins and
          relay changes. Closes tickets 22321, 24678, 22527, 24135,
          and 24695.
    
      o Minor features (fallback directory mirror configuration):
        - Add a nickname to each fallback in a C comment. This makes it
          easier for operators to find their relays, and allows stem to use
          nicknames to identify fallbacks. Implements ticket 24600.
        - Add a type and version header to the fallback directory mirror
          file. Also add a delimiter to the end of each fallback entry. This
          helps external parsers like stem and Relay Search. Implements
          ticket 24725.
        - Add an extrainfo cache flag for each fallback in a C comment. This
          allows stem to use fallbacks to fetch extra-info documents, rather
          than using authorities. Implements ticket 22759.
        - Add the generateFallbackDirLine.py script for automatically
          generating fallback directory mirror lines from relay fingerprints.
          No more typos! Add the lookupFallbackDirContact.py script for
          automatically looking up operator contact info from relay
          fingerprints. Implements ticket 24706, patch by teor and atagar.
        - Reject any fallback directory mirror that serves an expired
          consensus. Implements ticket 20942, patch by "minik".
        - Remove commas and equals signs from external string inputs to the
          fallback list. This avoids format confusion attacks. Implements
          ticket 24726.
        - Remove the "weight=10" line from fallback directory mirror
          entries. Ticket 24681 will maintain the current fallback weights
          by changing Tor's default fallback weight to 10. Implements
          ticket 24679.
        - Stop logging excessive information about fallback netblocks.
          Implements ticket 24791.
    
      o Minor features (forward-compatibility):
        - If a relay supports some link authentication protocol that we do
          not recognize, then include that relay's ed25519 key when telling
          other relays to extend to it. Previously, we treated future
          versions as if they were too old to support ed25519 link
          authentication. Closes ticket 20895.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the May 1 2018 Maxmind GeoLite2 Country
          database. Closes ticket 26104.
    
      o Minor features (heartbeat):
        - Add onion service information to our heartbeat logs, displaying
          stats about the activity of configured onion services. Closes
          ticket 24896.
    
      o Minor features (instrumentation, development):
        - Add the MainloopStats option to allow developers to get
          instrumentation information from the main event loop via the
          heartbeat messages. We hope to use this to improve Tor's behavior
          when it's trying to sleep. Closes ticket 24605.
    
      o Minor features (IPv6):
        - Make IPv6-only clients wait for microdescs for relays, even if we
          were previously using descriptors (or were using them as a bridge)
          and have a cached descriptor for them. Implements ticket 23827.
        - When a consensus has IPv6 ORPorts, make IPv6-only clients use
          them, rather than waiting to download microdescriptors. Implements
          ticket 23827.
    
      o Minor features (log messages):
        - Improve log message in the out-of-memory handler to include
          information about memory usage from the different compression
          backends. Closes ticket 25372.
        - Improve a warning message that happens when we fail to re-parse an
          old router because of an expired certificate. Closes ticket 20020.
        - Make the log more quantitative when we hit MaxMemInQueues
          threshold exposing some values. Closes ticket 24501.
    
      o Minor features (logging):
        - Clarify the log messages produced when getrandom() or a related
          entropy-generation mechanism gives an error. Closes ticket 25120.
        - Added support for the Android logging subsystem. Closes
          ticket 24362.
    
      o Minor features (performance):
        - Support predictive circuit building for onion service circuits
          with multiple layers of guards. Closes ticket 23101.
        - Use stdatomic.h where available, rather than mutexes, to implement
          atomic_counter_t. Closes ticket 23953.
    
      o Minor features (performance, 32-bit):
        - Improve performance on 32-bit systems by avoiding 64-bit division
          when calculating the timestamp in milliseconds for channel padding
          computations. Implements ticket 24613.
        - Improve performance on 32-bit systems by avoiding 64-bit division
          when timestamping cells and buffer chunks for OOM calculations.
          Implements ticket 24374.
    
      o Minor features (performance, OSX, iOS):
        - Use the mach_approximate_time() function (when available) to
          implement coarse monotonic time. Having a coarse time function
          should avoid a large number of system calls, and improve
          performance slightly, especially under load. Closes ticket 24427.
    
      o Minor features (performance, windows):
        - Improve performance on Windows Vista and Windows 7 by adjusting
          TCP send window size according to the recommendation from
          SIO_IDEAL_SEND_BACKLOG_QUERY. Closes ticket 22798. Patch
          from Vort.
    
      o Minor features (sandbox):
        - Explicitly permit the poll() system call when the Linux
          seccomp2-based sandbox is enabled: apparently, some versions of
          libc use poll() when calling getpwnam(). Closes ticket 25313.
    
      o Minor features (storage, configuration):
        - Users can store cached directory documents somewhere other than
          the DataDirectory by using the CacheDirectory option. Similarly,
          the storage location for relay's keys can be overridden with the
          KeyDirectory option. Closes ticket 22703.
    
      o Minor features (testing):
        - Add a "make test-rust" target to run the rust tests only. Closes
          ticket 25071.
    
      o Minor features (testing, debugging, embedding):
        - For development purposes, Tor now has a mode in which it runs for
          a few seconds, then stops, and starts again without exiting the
          process. This mode is meant to help us debug various issues with
          ticket 23847. To use this feature, compile with
          --enable-restart-debugging, and set the TOR_DEBUG_RESTART
          environment variable. This is expected to crash a lot, and is
          really meant for developers only. It will likely be removed in a
          future release. Implements ticket 24583.
    
      o Minor bugfixes (build, rust):
        - Fix output of autoconf checks to display success messages for Rust
          dependencies and a suitable rustc compiler version. Fixes bug
          24612; bugfix on 0.3.1.3-alpha.
        - Don't pass the --quiet option to cargo: it seems to suppress some
          errors, which is not what we want to do when building. Fixes bug
          24518; bugfix on 0.3.1.7.
        - Build correctly when building from outside Tor's source tree with
          the TOR_RUST_DEPENDENCIES option set. Fixes bug 22768; bugfix
          on 0.3.1.7.
    
      o Minor bugfixes (C correctness):
        - Fix a very unlikely (impossible, we believe) null pointer
          dereference. Fixes bug 25629; bugfix on 0.2.9.15. Found by
          Coverity; this is CID 1430932.
    
      o Minor bugfixes (channel, client):
        - Better identify client connection when reporting to the geoip
          client cache. Fixes bug 24904; bugfix on 0.3.1.7.
    
      o Minor bugfixes (circuit, cannibalization):
        - Don't cannibalize preemptively-built circuits if we no longer
          recognize their first hop. This situation can happen if our Guard
          relay went off the consensus after the circuit was created. Fixes
          bug 24469; bugfix on 0.0.6.
    
      o Minor bugfixes (client, backport from 0.3.4.1-alpha):
        - Don't consider Tor running as a client if the ControlPort is open,
          but no actual client ports are open. Fixes bug 26062; bugfix
          on 0.2.9.4-alpha.
    
      o Minor bugfixes (compilation):
        - Fix a C99 compliance issue in our configuration script that caused
          compilation issues when compiling Tor with certain versions of
          xtools. Fixes bug 25474; bugfix on 0.3.2.5-alpha.
    
      o Minor bugfixes (controller):
        - Restore the correct operation of the RESOLVE command, which had
          been broken since we added the ability to enable/disable DNS on
          specific listener ports. Fixes bug 25617; bugfix on 0.2.9.3-alpha.
        - Avoid a (nonfatal) assertion failure when extending a one-hop
          circuit from the controller to become a multihop circuit. Fixes
          bug 24903; bugfix on 0.2.5.2-alpha.
    
      o Minor bugfixes (correctness):
        - Remove a nonworking, unnecessary check to see whether a circuit
          hop's identity digest was set when the circuit failed. Fixes bug
          24927; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (correctness, client, backport from 0.3.4.1-alpha):
        - Upon receiving a malformed connected cell, stop processing the
          cell immediately. Previously we would mark the connection for
          close, but continue processing the cell as if the connection were
          open. Fixes bug 26072; bugfix on 0.2.4.7-alpha.
    
      o Minor bugfixes (directory authorities, IPv6):
        - When creating a routerstatus (vote) from a routerinfo (descriptor),
          set the IPv6 address to the unspecified IPv6 address, and
          explicitly initialize the port to zero. Fixes bug 24488; bugfix
          on 0.2.4.1-alpha.
    
      o Minor bugfixes (documentation):
        - Document that the PerConnBW{Rate,Burst} options will fall back to
          their corresponding consensus parameters only if those parameters
          are set. Previously we had claimed that these values would always
          be set in the consensus. Fixes bug 25296; bugfix on 0.2.2.7-alpha.
    
      o Minor bugfixes (documentation, backport from 0.3.4.1-alpha):
        - Stop saying in the manual that clients cache ipv4 dns answers from
          exit relays. We haven't used them since 0.2.6.3-alpha, and in
          ticket 24050 we stopped even caching them as of 0.3.2.6-alpha, but
          we forgot to say so in the man page. Fixes bug 26052; bugfix
          on 0.3.2.6-alpha.
    
      o Minor bugfixes (exit relay DNS retries):
        - Re-attempt timed-out DNS queries 3 times before failure, since our
          timeout is 5 seconds for them, but clients wait 10-15. Also allow
          slightly more timeouts per resolver when an exit has multiple
          resolvers configured. Fixes bug 21394; bugfix on 0.3.1.9.
    
      o Minor bugfixes (fallback directory mirrors):
        - Make updateFallbackDirs.py search harder for python. (Some OSs
          don't put it in /usr/bin.) Fixes bug 24708; bugfix
          on 0.2.8.1-alpha.
    
      o Minor bugfixes (hibernation, bandwidth accounting, shutdown):
        - When hibernating, close connections normally and allow them to
          flush. Fixes bug 23571; bugfix on 0.2.4.7-alpha. Also fixes
          bug 7267.
        - Do not attempt to launch self-reachability tests when entering
          hibernation. Fixes a case of bug 12062; bugfix on 0.0.9pre5.
        - Resolve several bugs related to descriptor fetching on bridge
          clients with bandwidth accounting enabled. (This combination is
          not recommended!) Fixes a case of bug 12062; bugfix
          on 0.2.0.3-alpha.
        - When hibernating, do not attempt to launch DNS checks. Fixes a
          case of bug 12062; bugfix on 0.1.2.2-alpha.
        - When hibernating, do not try to upload or download descriptors.
          Fixes a case of bug 12062; bugfix on 0.0.9pre5.
    
      o Minor bugfixes (IPv6, bridges):
        - Tor now always sets IPv6 preferences for bridges. Fixes bug 24573;
          bugfix on 0.2.8.2-alpha.
        - Tor now sets IPv6 address in the routerstatus as well as in the
          router descriptors when updating addresses for a bridge. Closes
          ticket 24572; bugfix on 0.2.4.5-alpha. Patch by "ffmancera".
    
      o Minor bugfixes (Linux seccomp2 sandbox):
        - When running with the sandbox enabled, reload configuration files
          correctly even when %include was used. Previously we would crash.
          Fixes bug 22605; bugfix on 0.3.1. Patch from Daniel Pinto.
    
      o Minor bugfixes (Linux seccomp2 sandbox, backport from 0.3.4.1-alpha):
        - Allow the nanosleep() system call, which glibc uses to implement
          sleep() and usleep(). Fixes bug 24969; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (logging):
        - Fix a (mostly harmless) race condition when invoking
          LOG_PROTOCOL_WARN message from a subthread while the torrc options
          are changing. Fixes bug 23954; bugfix on 0.1.1.9-alpha.
    
      o Minor bugfixes (man page, SocksPort):
        - Remove dead code from the old "SocksSocket" option, and rename
          SocksSocketsGroupWritable to UnixSocksGroupWritable. The old
          option still works, but is deprecated. Fixes bug 24343; bugfix
          on 0.2.6.3.
    
      o Minor bugfixes (memory leaks):
        - Avoid possible at-exit memory leaks related to use of Libevent's
          event_base_once() function. (This function tends to leak memory if
          the event_base is closed before the event fires.) Fixes bug 24584;
          bugfix on 0.2.8.1-alpha.
        - Fix a harmless memory leak in tor-resolve. Fixes bug 24582; bugfix
          on 0.2.1.1-alpha.
    
      o Minor bugfixes (network IPv6 test):
        - Tor's test scripts now check if "ping -6 ::1" works when the user
          runs "make test-network-all". Fixes bug 24677; bugfix on
          0.2.9.3-alpha. Patch by "ffmancera".
    
      o Minor bugfixes (networking):
        - string_is_valid_hostname() will not consider IP strings to be
          valid hostnames. Fixes bug 25055; bugfix on Tor 0.2.5.5.
    
      o Minor bugfixes (onion service v3):
        - Avoid an assertion failure when the next onion service descriptor
          rotation type is out of sync with the consensus's valid-after
          time. Instead, log a warning message with extra information, so we
          can better hunt down the cause of this assertion. Fixes bug 25306;
          bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (onion service, backport from 0.3.4.1-alpha):
        - Fix a memory leak when a v3 onion service is configured and gets a
          SIGHUP signal. Fixes bug 25901; bugfix on 0.3.2.1-alpha.
        - When parsing the descriptor signature, look for the token plus an
          extra white-space at the end. This is more correct but also will
          allow us to support new fields that might start with "signature".
          Fixes bug 26069; bugfix on 0.3.0.1-alpha.
    
      o Minor bugfixes (onion services):
        - If we are configured to offer a single onion service, don't log
          long-term established one hop rendezvous points in the heartbeat.
          Fixes bug 25116; bugfix on 0.2.9.6-rc.
    
      o Minor bugfixes (performance):
        - Reduce the number of circuits that will be opened at once during
          the circuit build timeout phase. This is done by increasing the
          idle timeout to 3 minutes, and lowering the maximum number of
          concurrent learning circuits to 10. Fixes bug 24769; bugfix
          on 0.3.1.1-alpha.
        - Avoid calling protocol_list_supports_protocol() from inside tight
          loops when running with cached routerinfo_t objects. Instead,
          summarize the relevant protocols as flags in the routerinfo_t, as
          we do for routerstatus_t objects. This change simplifies our code
          a little, and saves a large amount of short-term memory allocation
          operations. Fixes bug 25008; bugfix on 0.2.9.4-alpha.
    
      o Minor bugfixes (performance, timeouts):
        - Consider circuits for timeout as soon as they complete a hop. This
          is more accurate than applying the timeout in
          circuit_expire_building() because that function is only called
          once per second, which is now too slow for typical timeouts on the
          current network. Fixes bug 23114; bugfix on 0.2.2.2-alpha.
        - Use onion service circuits (and other circuits longer than 3 hops)
          to calculate a circuit build timeout. Previously, Tor only
          calculated its build timeout based on circuits that planned to be
          exactly 3 hops long. With this change, we include measurements
          from all circuits at the point where they complete their third
          hop. Fixes bug 23100; bugfix on 0.2.2.2-alpha.
    
      o Minor bugfixes (relay, crash, backport from 0.3.4.1-alpha):
        - Avoid a crash when running with DirPort set but ORPort turned off.
          Fixes a case of bug 23693; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (Rust FFI):
        - Fix a minor memory leak which would happen whenever the C code
          would call the Rust implementation of
          protover_get_supported_protocols(). This was due to the C version
          returning a static string, whereas the Rust version newly allocated
          a CString to pass across the FFI boundary. Consequently, the C
          code was not expecting to need to free() what it was given. Fixes
          bug 25127; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (spelling):
        - Use the "misspell" tool to detect and fix typos throughout the
          source code. Fixes bug 23650; bugfix on various versions of Tor.
          Patch from Deepesh Pathak.
    
      o Minor bugfixes (testing):
        - Avoid intermittent test failures due to a test that had relied on
          onion service introduction point creation finishing within 5
          seconds of real clock time. Fixes bug 25450; bugfix
          on 0.3.1.3-alpha.
        - Give out Exit flags in bootstrapping networks. Fixes bug 24137;
          bugfix on 0.2.3.1-alpha.
    
      o Minor bugfixes (unit test, monotonic time):
        - Increase a constant (1msec to 10msec) in the monotonic time test
          that makes sure the nsec/usec/msec times read are synchronized.
          This change was needed to accommodate slow systems like armel or
          when the clock_gettime() is not a VDSO on the running kernel.
          Fixes bug 25113; bugfix on 0.2.9.1.
    
      o Code simplification and refactoring:
        - Move the list of default directory authorities to its own file.
          Closes ticket 24854. Patch by "beastr0".
        - Remove the old (deterministic) directory retry logic entirely:
          We've used exponential backoff exclusively for some time. Closes
          ticket 23814.
        - Remove the unused nodelist_recompute_all_hsdir_indices(). Closes
          ticket 25108.
        - Remove a series of counters used to track circuit extend attempts
          and connection status but that in reality we aren't using for
          anything other than stats logged by a SIGUSR1 signal. Closes
          ticket 25163.
        - Remove /usr/athena from search path in configure.ac. Closes
          ticket 24363.
        - Remove duplicate code in node_has_curve25519_onion_key() and
          node_get_curve25519_onion_key(), and add a check for a zero
          microdesc curve25519 onion key. Closes ticket 23966, patch by
          "aruna1234" and teor.
        - Rewrite channel_rsa_id_group_set_badness to reduce temporary
          memory allocations with large numbers of OR connections (e.g.
          relays). Closes ticket 24119.
        - Separate the function that deletes ephemeral files when Tor
          stops gracefully.
        - Small changes to Tor's buf_t API to make it suitable for use as a
          general-purpose safe string constructor. Closes ticket 22342.
        - Switch -Wnormalized=id to -Wnormalized=nfkc in configure.ac to
          avoid source code identifier confusion. Closes ticket 24467.
        - The tor_git_revision[] constant no longer needs to be redeclared
          by everything that links against the rest of Tor. Done as part of
          ticket 23845, to simplify our external API.
        - We make extend_info_from_node() use node_get_curve25519_onion_key()
          introduced in ticket 23577 to access the curve25519 public keys
          rather than accessing it directly. Closes ticket 23760. Patch by
          Neel Chauhan.
        - Add a function to log channels' scheduler state changes to aid
          debugging efforts. Closes ticket 24531.
    
      o Documentation:
        - Improved the documentation of AccountingStart parameter. Closes
          ticket 23635.
        - Update the documentation for "Log" to include the current list of
          logging domains. Closes ticket 25378.
        - Add documentation on how to build tor with Rust dependencies
          without having to be online. Closes ticket 22907; bugfix
          on 0.3.0.3-alpha.
        - Clarify the behavior of RelayBandwidth{Rate,Burst} with client
          traffic. Closes ticket 24318.
        - Document that OutboundBindAddress doesn't apply to DNS requests.
          Closes ticket 22145. Patch from Aruna Maurya.
    
      o Code simplification and refactoring (channels):
        - Remove the incoming and outgoing channel queues. These were never
          used, but still took up a step in our fast path.
        - The majority of the channel unit tests have been rewritten and the
          code coverage has now been raised to 83.6% for channel.c. Closes
          ticket 23709.
        - Remove other dead code from the channel subsystem: All together,
          this cleanup has removed more than 1500 lines of code overall and
          adding very little except for unit test.
    
      o Code simplification and refactoring (circuit rendezvous):
        - Split the client-side rendezvous circuit lookup into two
          functions: one that returns only established circuits and another
          that returns all kinds of circuits. Closes ticket 23459.
    
      o Code simplification and refactoring (controller):
        - Make most of the variables in networkstatus_getinfo_by_purpose()
          const. Implements ticket 24489.
    
      o Documentation (backport from 0.3.4.1-alpha):
        - Correct an IPv6 error in the documentation for ExitPolicy. Closes
          ticket 25857. Patch from "CTassisF".
    
      o Documentation (man page):
        - The HiddenServiceVersion torrc option accepts only one number:
          either version 2 or 3. Closes ticket 25026; bugfix
          on 0.3.2.2-alpha.
    
      o Documentation (manpage, denial of service):
        - Provide more detail about the denial-of-service options, by
          listing each mitigation and explaining how they relate. Closes
          ticket 25248.
    
    
    Changes in version 0.3.1.10 - 2018-03-03
      Tor 0.3.1.10 backports a number of bugfixes, including important fixes for
      security issues.
    
      It includes an important security fix for a remote crash attack
      against directory authorities, tracked as TROVE-2018-001.
    
      This release also backports our new system for improved resistance to
      denial-of-service attacks against relays.
    
      This release also fixes several minor bugs and annoyances from
      earlier releases.
    
      All directory authorities should upgrade to one of the versions
      released today. Relays running 0.3.1.x may wish to update to one of
      the versions released today, for the DoS mitigations.
    
      Please note: according to our release calendar, Tor 0.3.1 will no
      longer be supported after 1 July 2018. If you will be running Tor
      after that date, you should make sure to plan to upgrade to the latest
      stable version, or downgrade to 0.2.9 (which will receive long-term
      support).
    
      o Major bugfixes (denial-of-service, directory authority, backport from 0.3.3.3-alpha):
        - Fix a protocol-list handling bug that could be used to remotely crash
          directory authorities with a null-pointer exception. Fixes bug 25074;
          bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-001 and
          CVE-2018-0490.
    
      o Major features (denial-of-service mitigation, backport from 0.3.3.2-alpha):
        - Give relays some defenses against the recent network overload. We
          start with three defenses (default parameters in parentheses).
          First: if a single client address makes too many concurrent
          connections (>100), hang up on further connections. Second: if a
          single client address makes circuits too quickly (more than 3 per
          second, with an allowed burst of 90) while also having too many
          connections open (3), refuse new create cells for the next while
          (1-2 hours). Third: if a client asks to establish a rendezvous
          point to you directly, ignore the request. These defenses can be
          manually controlled by new torrc options, but relays will also
          take guidance from consensus parameters, so there's no need to
          configure anything manually. Implements ticket 24902.
    
      o Minor features (linux seccomp2 sandbox, backport from 0.3.2.5-alpha):
        - Update the sandbox rules so that they should now work correctly
          with Glibc 2.26. Closes ticket 24315.
    
      o Major bugfixes (onion services, retry behavior, backport from 0.3.3.1-alpha):
        - Fix an "off by 2" error in counting rendezvous failures on the
          onion service side. While we thought we would stop the rendezvous
          attempt after one failed circuit, we were actually making three
          circuit attempts before giving up. Now switch to a default of 2,
          and allow the consensus parameter "hs_service_max_rdv_failures" to
          override. Fixes bug 24895; bugfix on 0.0.6.
    
      o Major bugfixes (protocol versions, backport from 0.3.3.2-alpha):
        - Add Link protocol version 5 to the supported protocols list. Fixes
          bug 25070; bugfix on 0.3.1.1-alpha.
    
      o Major bugfixes (relay, backport from 0.3.3.1-alpha):
        - Fix a set of false positives where relays would consider
          connections to other relays as being client-only connections (and
          thus e.g. deserving different link padding schemes) if those
          relays fell out of the consensus briefly. Now we look only at the
          initial handshake and whether the connection authenticated as a
          relay. Fixes bug 24898; bugfix on 0.3.1.1-alpha.
    
      o Minor features (denial-of-service avoidance, backport from 0.3.3.2-alpha):
        - Make our OOM handler aware of the geoip client history cache so it
          doesn't fill up the memory. This check is important for IPv6 and
          our DoS mitigation subsystem. Closes ticket 25122.
    
      o Minor feature (relay statistics, backport from 0.3.2.6-alpha):
        - Change relay bandwidth reporting stats interval from 4 hours to 24
          hours in order to reduce the efficiency of guard discovery
          attacks. Fixes ticket 23856.
    
      o Minor features (compatibility, OpenSSL, backport from 0.3.3.3-alpha):
        - Tor will now support TLS1.3 once OpenSSL 1.1.1 is released.
          Previous versions of Tor would not have worked with OpenSSL 1.1.1,
          since they neither disabled TLS 1.3 nor enabled any of the
          ciphersuites it requires. Now we enable the TLS 1.3 ciphersuites.
          Closes ticket 24978.
    
      o Minor features (fallback directory mirrors, backport from 0.3.2.9):
        - The fallback directory list has been re-generated based on the
          current status of the network. Tor uses fallback directories to
          bootstrap when it doesn't yet have up-to-date directory
          information. Closes ticket 24801.
        - Make the default DirAuthorityFallbackRate 0.1, so that clients
          prefer to bootstrap from fallback directory mirrors. This is a
          follow-up to 24679, which removed weights from the default
          fallbacks. Implements ticket 24681.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 7 2018 Maxmind GeoLite2
          Country database.
    
      o Minor bugfix (channel connection, backport from 0.3.3.2-alpha):
        - Use the actual observed address of an incoming relay connection,
          not the canonical address of the relay from its descriptor, when
          making decisions about how to handle the incoming connection.
          Fixes bug 24952; bugfix on 0.2.4.11-alpha. Patch by "ffmancera".
    
      o Minor bugfix (directory authority, backport from 0.3.3.2-alpha):
        - Directory authorities, when refusing a descriptor from a rejected
          relay, now explicitly tell the relay (in its logs) to set a valid
          ContactInfo address and contact the bad-relays@ mailing list.
          Fixes bug 25170; bugfix on 0.2.9.1.
    
      o Minor bugfixes (address selection, backport from 0.3.2.9):
        - When the fascist_firewall_choose_address_ functions don't find a
          reachable address, set the returned address to the null address
          and port. This is a precautionary measure, because some callers do
          not check the return value. Fixes bug 24736; bugfix
          on 0.2.8.2-alpha.
    
      o Major bugfixes (bootstrapping, backport from 0.3.2.5-alpha):
        - Fetch descriptors aggressively whenever we lack enough to build
          circuits, regardless of how many descriptors we are missing.
          Previously, we would delay launching the fetch when we had fewer
          than 15 missing descriptors, even if some of those descriptors
          were blocking circuits from building. Fixes bug 23985; bugfix on
          0.1.1.11-alpha. The effects of this bug became worse in
          0.3.0.3-alpha, when we began treating missing descriptors from our
          primary guards as a reason to delay circuits.
        - Don't try fetching microdescriptors from relays that have failed
          to deliver them in the past. Fixes bug 23817; bugfix
          on 0.3.0.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.3.2.7-rc):
        - Fix a signed/unsigned comparison warning introduced by our fix to
          TROVE-2017-009. Fixes bug 24480; bugfix on 0.2.5.16.
    
      o Minor bugfixes (control port, linux seccomp2 sandbox, backport from 0.3.2.5-alpha):
        - Avoid a crash when attempting to use the seccomp2 sandbox together
          with the OwningControllerProcess feature. Fixes bug 24198; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (denial-of-service, backport from 0.3.3.3-alpha):
        - Fix a possible crash on malformed consensus. If a consensus had
          contained an unparseable protocol line, it could have made clients
          and relays crash with a null-pointer exception. To exploit this
          issue, however, an attacker would need to be able to subvert the
          directory authority system. Fixes bug 25251; bugfix on
          0.2.9.4-alpha. Also tracked as TROVE-2018-004.
    
      o Minor bugfixes (directory cache, backport from 0.3.2.5-alpha):
        - Recover better from empty or corrupt files in the consensus cache
          directory. Fixes bug 24099; bugfix on 0.3.1.1-alpha.
        - When a consensus diff calculation is only partially successful,
          only record the successful parts as having succeeded. Partial
          success can happen if (for example) one compression method fails
          but the others succeed. Previously we misrecorded all the
          calculations as having succeeded, which would later cause a
          nonfatal assertion failure. Fixes bug 24086; bugfix
          on 0.3.1.1-alpha.
    
      o Minor bugfixes (entry guards, backport from 0.3.2.3-alpha):
        - Tor now updates its guard state when it reads a consensus
          regardless of whether it's missing descriptors. That makes tor use
          its primary guards to fetch descriptors in some edge cases where
          it would previously have used fallback directories. Fixes bug
          23862; bugfix on 0.3.0.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.3.3.2-alpha):
        - Don't treat inability to store a cached consensus object as a bug:
          it can happen normally when we are out of disk space. Fixes bug
          24859; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (memory usage, backport from 0.3.2.8-rc):
        - When queuing DESTROY cells on a channel, only queue the circuit-id
          and reason fields: not the entire 514-byte cell. This fix should
          help mitigate any bugs or attacks that fill up these queues, and
          free more RAM for other uses. Fixes bug 24666; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (network layer, backport from 0.3.2.5-alpha):
        - When closing a connection via close_connection_immediately(), we
          mark it as "not blocked on bandwidth", to prevent later calls from
          trying to unblock it, and give it permission to read. This fixes a
          backtrace warning that can happen on relays under various
          circumstances. Fixes bug 24167; bugfix on 0.1.0.1-rc.
    
      o Minor bugfixes (path selection, backport from 0.3.2.4-alpha):
        - When selecting relays by bandwidth, avoid a rounding error that
          could sometimes cause load to be imbalanced incorrectly.
          Previously, we would always round upwards; now, we round towards
          the nearest integer. This had the biggest effect when a relay's
          weight adjustments should have given it weight 0, but it got
          weight 1 instead. Fixes bug 23318; bugfix on 0.2.4.3-alpha.
        - When calculating the fraction of nodes that have descriptors, and
          all nodes in the network have zero bandwidths, count the number of
          nodes instead. Fixes bug 23318; bugfix on 0.2.4.10-alpha.
        - Actually log the total bandwidth in compute_weighted_bandwidths().
          Fixes bug 24170; bugfix on 0.2.4.3-alpha.
    
      o Minor bugfixes (performance, fragile-hardening, backport from 0.3.3.1-alpha):
        - Improve the performance of our consensus-diff application code
          when Tor is built with the --enable-fragile-hardening option set.
          Fixes bug 24826; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (OSX, backport from 0.3.3.1-alpha):
        - Don't exit the Tor process if setrlimit() fails to change the file
          limit (which can happen sometimes on some versions of OSX). Fixes
          bug 21074; bugfix on 0.0.9pre5.
    
      o Minor bugfixes (portability, msvc, backport from 0.3.2.9):
        - Fix a bug in the bit-counting parts of our timing-wheel code on
          MSVC. (Note that MSVC is still not a supported build platform, due
          to cyptographic timing channel risks.) Fixes bug 24633; bugfix
          on 0.2.9.1-alpha.
    
      o Minor bugfixes (relay, partial backport):
        - Make the internal channel_is_client() function look at what sort
          of connection handshake the other side used, rather than whether
          the other side ever sent a create_fast cell to us. Backports part
          of the fixes from bugs 22805 and 24898.
    
      o Minor bugfixes (spec conformance, backport from 0.3.3.3-alpha):
        - Forbid "-0" as a protocol version. Fixes part of bug 25249; bugfix on
          0.2.9.4-alpha.
        - Forbid UINT32_MAX as a protocol version. Fixes part of bug 25249;
          bugfix on 0.2.9.4-alpha.
    
      o Code simplification and refactoring (backport from 0.3.3.3-alpha):
        - Update the "rust dependencies" submodule to be a project-level
          repository, rather than a user repository. Closes ticket 25323.
    
    
    Changes in version 0.2.9.15 - 2018-03-03
      Tor 0.2.9.15 backports important security and stability bugfixes from
      later Tor releases.
    
      It includes an important security fix for a remote crash attack
      against directory authorities, tracked as TROVE-2018-001.
    
      This release also backports our new system for improved resistance to
      denial-of-service attacks against relays.
    
      This release also fixes several minor bugs and annoyances from
      earlier releases.
    
      All directory authorities should upgrade to one of the versions
      released today. Relays running 0.2.9.x may wish to update to one of
      the versions released today, for the DoS mitigations.
    
      o Major bugfixes (denial-of-service, directory authority, backport from 0.3.3.3-alpha):
        - Fix a protocol-list handling bug that could be used to remotely crash
          directory authorities with a null-pointer exception. Fixes bug 25074;
          bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-001 and
          CVE-2018-0490.
    
      o Major features (denial-of-service mitigation):
        - Give relays some defenses against the recent network overload. We
          start with three defenses (default parameters in parentheses).
          First: if a single client address makes too many concurrent
          connections (>100), hang up on further connections. Second: if a
          single client address makes circuits too quickly (more than 3 per
          second, with an allowed burst of 90) while also having too many
          connections open (3), refuse new create cells for the next while
          (1-2 hours). Third: if a client asks to establish a rendezvous
          point to you directly, ignore the request. These defenses can be
          manually controlled by new torrc options, but relays will also
          take guidance from consensus parameters, so there's no need to
          configure anything manually. Implements ticket 24902.
    
      o Major bugfixes (bootstrapping):
        - Fetch descriptors aggressively whenever we lack enough to build
          circuits, regardless of how many descriptors we are missing.
          Previously, we would delay launching the fetch when we had fewer
          than 15 missing descriptors, even if some of those descriptors
          were blocking circuits from building. Fixes bug 23985; bugfix on
          0.1.1.11-alpha. The effects of this bug became worse in
          0.3.0.3-alpha, when we began treating missing descriptors from our
          primary guards as a reason to delay circuits.
    
      o Major bugfixes (onion services, retry behavior):
        - Fix an "off by 2" error in counting rendezvous failures on the
          onion service side. While we thought we would stop the rendezvous
          attempt after one failed circuit, we were actually making three
          circuit attempts before giving up. Now switch to a default of 2,
          and allow the consensus parameter "hs_service_max_rdv_failures" to
          override. Fixes bug 24895; bugfix on 0.0.6.
    
      o Minor feature (relay statistics):
        - Change relay bandwidth reporting stats interval from 4 hours to 24
          hours in order to reduce the efficiency of guard discovery
          attacks. Fixes ticket 23856.
    
      o Minor features (compatibility, OpenSSL):
        - Tor will now support TLS1.3 once OpenSSL 1.1.1 is released.
          Previous versions of Tor would not have worked with OpenSSL 1.1.1,
          since they neither disabled TLS 1.3 nor enabled any of the
          ciphersuites it requires. Now we enable the TLS 1.3 ciphersuites.
          Closes ticket 24978.
    
      o Minor features (denial-of-service avoidance):
        - Make our OOM handler aware of the geoip client history cache so it
          doesn't fill up the memory. This check is important for IPv6 and
          our DoS mitigation subsystem. Closes ticket 25122.
    
      o Minor features (fallback directory mirrors):
        - The fallback directory list has been re-generated based on the
          current status of the network. Tor uses fallback directories to
          bootstrap when it doesn't yet have up-to-date directory
          information. Closes ticket 24801.
        - Make the default DirAuthorityFallbackRate 0.1, so that clients
          prefer to bootstrap from fallback directory mirrors. This is a
          follow-up to 24679, which removed weights from the default
          fallbacks. Implements ticket 24681.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 7 2018 Maxmind GeoLite2
          Country database.
    
      o Minor features (linux seccomp2 sandbox):
        - Update the sandbox rules so that they should now work correctly
          with Glibc 2.26. Closes ticket 24315.
    
      o Minor bugfix (channel connection):
        - Use the actual observed address of an incoming relay connection,
          not the canonical address of the relay from its descriptor, when
          making decisions about how to handle the incoming connection.
          Fixes bug 24952; bugfix on 0.2.4.11-alpha. Patch by "ffmancera".
    
      o Minor bugfix (directory authority):
        - Directory authorities, when refusing a descriptor from a rejected
          relay, now explicitly tell the relay (in its logs) to set a valid
          ContactInfo address and contact the bad-relays@ mailing list.
          Fixes bug 25170; bugfix on 0.2.9.1.
    
      o Minor bugfixes (address selection):
        - When the fascist_firewall_choose_address_ functions don't find a
          reachable address, set the returned address to the null address
          and port. This is a precautionary measure, because some callers do
          not check the return value. Fixes bug 24736; bugfix
          on 0.2.8.2-alpha.
    
      o Minor bugfixes (compilation):
        - Fix a signed/unsigned comparison warning introduced by our fix to
          TROVE-2017-009. Fixes bug 24480; bugfix on 0.2.5.16.
    
      o Minor bugfixes (control port, linux seccomp2 sandbox):
        - Avoid a crash when attempting to use the seccomp2 sandbox together
          with the OwningControllerProcess feature. Fixes bug 24198; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (denial-of-service, backport from 0.3.3.3-alpha):
        - Fix a possible crash on malformed consensus. If a consensus had
          contained an unparseable protocol line, it could have made clients
          and relays crash with a null-pointer exception. To exploit this
          issue, however, an attacker would need to be able to subvert the
          directory authority system. Fixes bug 25251; bugfix on
          0.2.9.4-alpha. Also tracked as TROVE-2018-004.
    
      o Minor bugfixes (memory usage):
        - When queuing DESTROY cells on a channel, only queue the circuit-id
          and reason fields: not the entire 514-byte cell. This fix should
          help mitigate any bugs or attacks that fill up these queues, and
          free more RAM for other uses. Fixes bug 24666; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (network layer):
        - When closing a connection via close_connection_immediately(), we
          mark it as "not blocked on bandwidth", to prevent later calls from
          trying to unblock it, and give it permission to read. This fixes a
          backtrace warning that can happen on relays under various
          circumstances. Fixes bug 24167; bugfix on 0.1.0.1-rc.
    
      o Minor bugfixes (OSX):
        - Don't exit the Tor process if setrlimit() fails to change the file
          limit (which can happen sometimes on some versions of OSX). Fixes
          bug 21074; bugfix on 0.0.9pre5.
    
      o Minor bugfixes (path selection):
        - When selecting relays by bandwidth, avoid a rounding error that
          could sometimes cause load to be imbalanced incorrectly.
          Previously, we would always round upwards; now, we round towards
          the nearest integer. This had the biggest effect when a relay's
          weight adjustments should have given it weight 0, but it got
          weight 1 instead. Fixes bug 23318; bugfix on 0.2.4.3-alpha.
        - When calculating the fraction of nodes that have descriptors, and
          all nodes in the network have zero bandwidths, count the number of
          nodes instead. Fixes bug 23318; bugfix on 0.2.4.10-alpha.
        - Actually log the total bandwidth in compute_weighted_bandwidths().
          Fixes bug 24170; bugfix on 0.2.4.3-alpha.
    
      o Minor bugfixes (portability, msvc):
        - Fix a bug in the bit-counting parts of our timing-wheel code on
          MSVC. (Note that MSVC is still not a supported build platform, due
          to cryptographic timing channel risks.) Fixes bug 24633; bugfix
          on 0.2.9.1-alpha.
    
      o Minor bugfixes (relay):
        - Make the internal channel_is_client() function look at what sort
          of connection handshake the other side used, rather than whether
          the other side ever sent a create_fast cell to us. Backports part
          of the fixes from bugs 22805 and 24898.
    
      o Minor bugfixes (spec conformance, backport from 0.3.3.3-alpha):
        - Forbid "-0" as a protocol version. Fixes part of bug 25249; bugfix on
          0.2.9.4-alpha.
        - Forbid UINT32_MAX as a protocol version. Fixes part of bug 25249;
          bugfix on 0.2.9.4-alpha.
    
    
    Changes in version 0.3.2.10 - 2018-03-03
      Tor 0.3.2.10 is the second stable release in the 0.3.2 series. It
      backports a number of bugfixes, including important fixes for security
      issues.
    
      It includes an important security fix for a remote crash attack
      against directory authorities, tracked as TROVE-2018-001.
    
      Additionally, it backports a fix for a bug whose severity we have
      upgraded: Bug 24700, which was fixed in 0.3.3.2-alpha, can be remotely
      triggered in order to crash relays with a use-after-free pattern. As
      such, we are now tracking that bug as TROVE-2018-002 and
      CVE-2018-0491, and backporting it to earlier releases. This bug
      affected versions 0.3.2.1-alpha through 0.3.2.9, as well as version
      0.3.3.1-alpha.
    
      This release also backports our new system for improved resistance to
      denial-of-service attacks against relays.
    
      This release also fixes several minor bugs and annoyances from
      earlier releases.
    
      Relays running 0.3.2.x SHOULD upgrade to one of the versions released
      today, for the fix to TROVE-2018-002. Directory authorities should
      also upgrade. (Relays on earlier versions might want to update too for
      the DoS mitigations.)
    
      o Major bugfixes (denial-of-service, directory authority, backport from 0.3.3.3-alpha):
        - Fix a protocol-list handling bug that could be used to remotely crash
          directory authorities with a null-pointer exception. Fixes bug 25074;
          bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-001 and
          CVE-2018-0490.
    
      o Major bugfixes (scheduler, KIST, denial-of-service, backport from 0.3.3.2-alpha):
        - Avoid adding the same channel twice in the KIST scheduler pending
          list, which could lead to remote denial-of-service use-after-free
          attacks against relays. Fixes bug 24700; bugfix on 0.3.2.1-alpha.
    
      o Major features (denial-of-service mitigation, backport from 0.3.3.2-alpha):
        - Give relays some defenses against the recent network overload. We
          start with three defenses (default parameters in parentheses).
          First: if a single client address makes too many concurrent
          connections (>100), hang up on further connections. Second: if a
          single client address makes circuits too quickly (more than 3 per
          second, with an allowed burst of 90) while also having too many
          connections open (3), refuse new create cells for the next while
          (1-2 hours). Third: if a client asks to establish a rendezvous
          point to you directly, ignore the request. These defenses can be
          manually controlled by new torrc options, but relays will also
          take guidance from consensus parameters, so there's no need to
          configure anything manually. Implements ticket 24902.
    
      o Major bugfixes (onion services, retry behavior, backport from 0.3.3.1-alpha):
        - Fix an "off by 2" error in counting rendezvous failures on the
          onion service side. While we thought we would stop the rendezvous
          attempt after one failed circuit, we were actually making three
          circuit attempts before giving up. Now switch to a default of 2,
          and allow the consensus parameter "hs_service_max_rdv_failures" to
          override. Fixes bug 24895; bugfix on 0.0.6.
        - New-style (v3) onion services now obey the "max rendezvous circuit
          attempts" logic. Previously they would make as many rendezvous
          circuit attempts as they could fit in the MAX_REND_TIMEOUT second
          window before giving up. Fixes bug 24894; bugfix on 0.3.2.1-alpha.
    
      o Major bugfixes (protocol versions, backport from 0.3.3.2-alpha):
        - Add Link protocol version 5 to the supported protocols list. Fixes
          bug 25070; bugfix on 0.3.1.1-alpha.
    
      o Major bugfixes (relay, backport from 0.3.3.1-alpha):
        - Fix a set of false positives where relays would consider
          connections to other relays as being client-only connections (and
          thus e.g. deserving different link padding schemes) if those
          relays fell out of the consensus briefly. Now we look only at the
          initial handshake and whether the connection authenticated as a
          relay. Fixes bug 24898; bugfix on 0.3.1.1-alpha.
    
      o Major bugfixes (scheduler, consensus, backport from 0.3.3.2-alpha):
        - The scheduler subsystem was failing to promptly notice changes in
          consensus parameters, making it harder to switch schedulers
          network-wide. Fixes bug 24975; bugfix on 0.3.2.1-alpha.
    
      o Minor features (denial-of-service avoidance, backport from 0.3.3.2-alpha):
        - Make our OOM handler aware of the geoip client history cache so it
          doesn't fill up the memory. This check is important for IPv6 and
          our DoS mitigation subsystem. Closes ticket 25122.
    
      o Minor features (compatibility, OpenSSL, backport from 0.3.3.3-alpha):
        - Tor will now support TLS1.3 once OpenSSL 1.1.1 is released.
          Previous versions of Tor would not have worked with OpenSSL 1.1.1,
          since they neither disabled TLS 1.3 nor enabled any of the
          ciphersuites it requires. Now we enable the TLS 1.3 ciphersuites.
          Closes ticket 24978.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 7 2018 Maxmind GeoLite2
          Country database.
    
      o Minor features (logging, diagnostic, backport from 0.3.3.2-alpha):
        - When logging a failure to create an onion service's descriptor,
          also log what the problem with the descriptor was. Diagnostic
          for ticket 24972.
    
      o Minor bugfix (channel connection, backport from 0.3.3.2-alpha):
        - Use the actual observed address of an incoming relay connection,
          not the canonical address of the relay from its descriptor, when
          making decisions about how to handle the incoming connection.
          Fixes bug 24952; bugfix on 0.2.4.11-alpha. Patch by "ffmancera".
    
      o Minor bugfixes (denial-of-service, backport from 0.3.3.3-alpha):
        - Fix a possible crash on malformed consensus. If a consensus had
          contained an unparseable protocol line, it could have made clients
          and relays crash with a null-pointer exception. To exploit this
          issue, however, an attacker would need to be able to subvert the
          directory authority system. Fixes bug 25251; bugfix on
          0.2.9.4-alpha. Also tracked as TROVE-2018-004.
    
      o Minor bugfix (directory authority, backport from 0.3.3.2-alpha):
        - Directory authorities, when refusing a descriptor from a rejected
          relay, now explicitly tell the relay (in its logs) to set a valid
          ContactInfo address and contact the bad-relays@ mailing list.
          Fixes bug 25170; bugfix on 0.2.9.1.
    
      o Minor bugfixes (build, rust, backport from 0.3.3.1-alpha):
        - When building with Rust on OSX, link against libresolv, to work
          around the issue at https://github.com/rust-lang/rust/issues/46797.
          Fixes bug 24652; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (onion services, backport from 0.3.3.2-alpha):
        - Remove a BUG() statement when a client fetches an onion descriptor
          that has a lower revision counter than the one in its cache. This
          can happen in normal circumstances due to HSDir desync. Fixes bug
          24976; bugfix on 0.3.2.1-alpha.
    
      o Minor bugfixes (logging, backport from 0.3.3.2-alpha):
        - Don't treat inability to store a cached consensus object as a bug:
          it can happen normally when we are out of disk space. Fixes bug
          24859; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (performance, fragile-hardening, backport from 0.3.3.1-alpha):
        - Improve the performance of our consensus-diff application code
          when Tor is built with the --enable-fragile-hardening option set.
          Fixes bug 24826; bugfix on 0.3.1.1-alpha.
    
      o Minor bugfixes (OSX, backport from 0.3.3.1-alpha):
        - Don't exit the Tor process if setrlimit() fails to change the file
          limit (which can happen sometimes on some versions of OSX). Fixes
          bug 21074; bugfix on 0.0.9pre5.
    
      o Minor bugfixes (spec conformance, backport from 0.3.3.3-alpha):
        - Forbid "-0" as a protocol version. Fixes part of bug 25249; bugfix on
          0.2.9.4-alpha.
        - Forbid UINT32_MAX as a protocol version. Fixes part of bug 25249;
          bugfix on 0.2.9.4-alpha.
    
      o Minor bugfixes (testing, backport from 0.3.3.1-alpha):
        - Fix a memory leak in the scheduler/loop_kist unit test. Fixes bug
          25005; bugfix on 0.3.2.7-rc.
    
      o Minor bugfixes (v3 onion services, backport from 0.3.3.2-alpha):
        - Look at the "HSRend" protocol version, not the "HSDir" protocol
          version, when deciding whether a consensus entry can support the
          v3 onion service protocol as a rendezvous point. Fixes bug 25105;
          bugfix on 0.3.2.1-alpha.
    
      o Code simplification and refactoring (backport from 0.3.3.3-alpha):
        - Update the "rust dependencies" submodule to be a project-level
          repository, rather than a user repository. Closes ticket 25323.
    
      o Documentation (backport from 0.3.3.1-alpha)
        - Document that operators who run more than one relay or bridge are
          expected to set MyFamily and ContactInfo correctly. Closes
          ticket 24526.
    
    
    Changes in version 0.3.2.9 - 2018-01-09
      Tor 0.3.2.9 is the first stable release in the 0.3.2 series.
    
      The 0.3.2 series includes our long-anticipated new onion service
      design, with numerous security features. (For more information, see
      our blog post at https://blog.torproject.org/fall-harvest.) We also
      have a new circuit scheduler algorithm for improved performance on
      relays everywhere (see https://blog.torproject.org/kist-and-tell),
      along with many smaller features and bugfixes.
    
      Per our stable release policy, we plan to support each stable release
      series for at least the next nine months, or for three months after
      the first stable release of the next series: whichever is longer. If
      you need a release with long-term support, we recommend that you stay
      with the 0.2.9 series.
    
      Below is a list of the changes since 0.3.1.7. For a list of all
      changes since 0.3.2.8-rc, see the ChangeLog file.
    
      o Directory authority changes:
        - Add "Bastet" as a ninth directory authority to the default list.
          Closes ticket 23910.
        - The directory authority "Longclaw" has changed its IP address.
          Closes ticket 23592.
        - Remove longclaw's IPv6 address, as it will soon change. Authority
          IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves
          3/8 directory authorities with IPv6 addresses, but there are also
          52 fallback directory mirrors with IPv6 addresses. Resolves 19760.
        - Add an IPv6 address for the "bastet" directory authority. Closes
          ticket 24394.
    
      o Major features (next-generation onion services):
        - Tor now supports the next-generation onion services protocol for
          clients and services! As part of this release, the core of
          proposal 224 has been implemented and is available for
          experimentation and testing by our users. This newer version of
          onion services ("v3") features many improvements over the legacy
          system, including:
    
          a) Better crypto (replaced SHA1/DH/RSA1024
          with SHA3/ed25519/curve25519)
    
          b) Improved directory protocol, leaking much less information to
          directory servers.
    
          c) Improved directory protocol, with smaller surface for
          targeted attacks.
    
          d) Better onion address security against impersonation.
    
          e) More extensible introduction/rendezvous protocol.
    
          f) A cleaner and more modular codebase.
    
          You can identify a next-generation onion address by its length:
          they are 56 characters long, as in
          "4acth47i6kxnvkewtm6q7ib2s3ufpo5sqbsnzjpbi7utijcltosqemad.onion".
    
          In the future, we will release more options and features for v3
          onion services, but we first need a testing period, so that the
          current codebase matures and becomes more robust. Planned features
          include: offline keys, advanced client authorization, improved
          guard algorithms, and statistics. For full details, see
          proposal 224.
    
          Legacy ("v2") onion services will still work for the foreseeable
          future, and will remain the default until this new codebase gets
          tested and hardened. Service operators who want to experiment with
          the new system can use the 'HiddenServiceVersion 3' torrc
          directive along with the regular onion service configuration
          options. For more information, see our blog post at
          "https://blog.torproject.org/fall-harvest". Enjoy!
    
      o Major feature (scheduler, channel):
        - Tor now uses new schedulers to decide which circuits should
          deliver cells first, in order to improve congestion at relays. The
          first type is called "KIST" ("Kernel Informed Socket Transport"),
          and is only available on Linux-like systems: it uses feedback from
          the kernel to prevent the kernel's TCP buffers from growing too
          full. The second new scheduler type is called "KISTLite": it
          behaves the same as KIST, but runs on systems without kernel
          support for inspecting TCP implementation details. The old
          scheduler is still available, under the name "Vanilla". To change
          the default scheduler preference order, use the new "Schedulers"
          option. (The default preference order is "KIST,KISTLite,Vanilla".)
    
          Matt Traudt implemented KIST, based on research by Rob Jansen,
          John Geddes, Christ Wacek, Micah Sherr, and Paul Syverson. For
          more information, see the design paper at
          http://www.robgjansen.com/publications/kist-sec2014.pdf and the
          followup implementation paper at https://arxiv.org/abs/1709.01044.
          Closes ticket 12541. For more information, see our blog post at
          "https://blog.torproject.org/kist-and-tell".
    
      o Major bugfixes (security, general):
        - Fix a denial of service bug where an attacker could use a
          malformed directory object to cause a Tor instance to pause while
          OpenSSL would try to read a passphrase from the terminal. (Tor
          instances run without a terminal, which is the case for most Tor
          packages, are not impacted.) Fixes bug 24246; bugfix on every
          version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821.
          Found by OSS-Fuzz as testcase 6360145429790720.
    
      o Major bugfixes (security, directory authority):
        - Fix a denial of service issue where an attacker could crash a
          directory authority using a malformed router descriptor. Fixes bug
          24245; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010
          and CVE-2017-8820.
    
      o Major bugfixes (security, onion service v2):
        - Fix a use-after-free error that could crash v2 Tor onion services
          when they failed to open circuits while expiring introduction
          points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is
          also tracked as TROVE-2017-013 and CVE-2017-8823.
        - When checking for replays in the INTRODUCE1 cell data for a
          (legacy) onion service, correctly detect replays in the RSA-
          encrypted part of the cell. We were previously checking for
          replays on the entire cell, but those can be circumvented due to
          the malleability of Tor's legacy hybrid encryption. This fix helps
          prevent a traffic confirmation attack. Fixes bug 24244; bugfix on
          0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009
          and CVE-2017-8819.
    
      o Major bugfixes (security, relay):
        - When running as a relay, make sure that we never build a path
          through ourselves, even in the case where we have somehow lost the
          version of our descriptor appearing in the consensus. Fixes part
          of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked
          as TROVE-2017-012 and CVE-2017-8822.
        - When running as a relay, make sure that we never choose ourselves
          as a guard. Fixes part of bug 21534; bugfix on 0.3.0.1-alpha. This
          issue is also tracked as TROVE-2017-012 and CVE-2017-8822.
    
      o Major bugfixes (bootstrapping):
        - Fetch descriptors aggressively whenever we lack enough to build
          circuits, regardless of how many descriptors we are missing.
          Previously, we would delay launching the fetch when we had fewer
          than 15 missing descriptors, even if some of those descriptors
          were blocking circuits from building. Fixes bug 23985; bugfix on
          0.1.1.11-alpha. The effects of this bug became worse in
          0.3.0.3-alpha, when we began treating missing descriptors from our
          primary guards as a reason to delay circuits.
        - Don't try fetching microdescriptors from relays that have failed
          to deliver them in the past. Fixes bug 23817; bugfix
          on 0.3.0.1-alpha.
    
      o Major bugfixes (circuit prediction):
        - Fix circuit prediction logic so that a client doesn't treat a port
          as being "handled" by a circuit if that circuit already has
          isolation settings on it. This change should make Tor clients more
          responsive by improving their chances of having a pre-created
          circuit ready for use when a request arrives. Fixes bug 18859;
          bugfix on 0.2.3.3-alpha.
    
      o Major bugfixes (exit relays, DNS):
        - Fix an issue causing DNS to fail on high-bandwidth exit nodes,
          making them nearly unusable. Fixes bugs 21394 and 18580; bugfix on
          0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for
          identifying and finding a workaround to this bug and to Moritz,
          Arthur Edelstein, and Roger for helping to track it down and
          analyze it.
    
      o Major bugfixes (relay, crash, assertion failure):
        - Fix a timing-based assertion failure that could occur when the
          circuit out-of-memory handler freed a connection's output buffer.
          Fixes bug 23690; bugfix on 0.2.6.1-alpha.
    
      o Major bugfixes (usability, control port):
        - Report trusted clock skew indications as bootstrap errors, so
          controllers can more easily alert users when their clocks are
          wrong. Fixes bug 23506; bugfix on 0.1.2.6-alpha.
    
      o Minor features (bridge):
        - Bridge relays can now set the BridgeDistribution config option to
          add a "bridge-distribution-request" line to their bridge
          descriptor, which tells BridgeDB how they'd like their bridge
          address to be given out. (Note that as of Oct 2017, BridgeDB does
          not yet implement this feature.) As a side benefit, this feature
          provides a way to distinguish bridge descriptors from non-bridge
          descriptors. Implements tickets 18329.
        - When handling the USERADDR command on an ExtOrPort, warn when the
          transports provides a USERADDR with no port. In a future version,
          USERADDR commands of this format may be rejected. Detects problems
          related to ticket 23080.
    
      o Minor features (bug detection):
        - Log a warning message with a stack trace for any attempt to call
          get_options() during option validation. This pattern has caused
          subtle bugs in the past. Closes ticket 22281.
    
      o Minor features (build, compilation):
        - The "check-changes" feature is now part of the "make check" tests;
          we'll use it to try to prevent misformed changes files from
          accumulating. Closes ticket 23564.
        - Tor builds should now fail if there are any mismatches between the
          C type representing a configuration variable and the C type the
          data-driven parser uses to store a value there. Previously, we
          needed to check these by hand, which sometimes led to mistakes.
          Closes ticket 23643.
    
      o Minor features (client):
        - You can now use Tor as a tunneled HTTP proxy: use the new
          HTTPTunnelPort option to open a port that accepts HTTP CONNECT
          requests. Closes ticket 22407.
        - Add an extra check to make sure that we always use the newer guard
          selection code for picking our guards. Closes ticket 22779.
        - When downloading (micro)descriptors, don't split the list into
          multiple requests unless we want at least 32 descriptors.
          Previously, we split at 4, not 32, which led to significant
          overhead in HTTP request size and degradation in compression
          performance. Closes ticket 23220.
        - Improve log messages when missing descriptors for primary guards.
          Resolves ticket 23670.
    
      o Minor features (command line):
        - Add a new commandline option, --key-expiration, which prints when
          the current signing key is going to expire. Implements ticket
          17639; patch by Isis Lovecruft.
    
      o Minor features (control port):
        - If an application tries to use the control port as an HTTP proxy,
          respond with a meaningful "This is the Tor control port" message,
          and log the event. Closes ticket 1667. Patch from Ravi
          Chandra Padmala.
        - Provide better error message for GETINFO desc/(id|name) when not
          fetching router descriptors. Closes ticket 5847. Patch by
          Kevin Butler.
        - Add GETINFO "{desc,md}/download-enabled", to inform the controller
          whether Tor will try to download router descriptors and
          microdescriptors respectively. Closes ticket 22684.
        - Added new GETINFO targets "ip-to-country/{ipv4,ipv6}-available",
          so controllers can tell whether the geoip databases are loaded.
          Closes ticket 23237.
        - Adds a timestamp field to the CIRC_BW and STREAM_BW bandwidth
          events. Closes ticket 19254. Patch by "DonnchaC".
    
      o Minor features (development support):
        - Developers can now generate a call-graph for Tor using the
          "calltool" python program, which post-processes object dumps. It
          should work okay on many Linux and OSX platforms, and might work
          elsewhere too. To run it, install calltool from
          https://gitweb.torproject.org/user/nickm/calltool.git and run
          "make callgraph". Closes ticket 19307.
    
      o Minor features (directory authority):
        - Make the "Exit" flag assignment only depend on whether the exit
          policy allows connections to ports 80 and 443. Previously relays
          would get the Exit flag if they allowed connections to one of
          these ports and also port 6667. Resolves ticket 23637.
    
      o Minor features (ed25519):
        - Add validation function to checks for torsion components in
          ed25519 public keys, used by prop224 client-side code. Closes
          ticket 22006. Math help by Ian Goldberg.
    
      o Minor features (exit relay, DNS):
        - Improve the clarity and safety of the log message from evdns when
          receiving an apparently spoofed DNS reply. Closes ticket 3056.
    
      o Minor features (fallback directory mirrors):
        - The fallback directory list has been re-generated based on the
          current status of the network. Tor uses fallback directories to
          bootstrap when it doesn't yet have up-to-date directory
          information. Closes ticket 24801.
        - Make the default DirAuthorityFallbackRate 0.1, so that clients
          prefer to bootstrap from fallback directory mirrors. This is a
          follow-up to 24679, which removed weights from the default
          fallbacks. Implements ticket 24681.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the January 5 2018 Maxmind GeoLite2
          Country database.
    
      o Minor features (integration, hardening):
        - Add a new NoExec option to prevent Tor from running other
          programs. When this option is set to 1, Tor will never try to run
          another program, regardless of the settings of
          PortForwardingHelper, ClientTransportPlugin, or
          ServerTransportPlugin. Once NoExec is set, it cannot be disabled
          without restarting Tor. Closes ticket 22976.
    
      o Minor features (linux seccomp2 sandbox):
        - Update the sandbox rules so that they should now work correctly
          with Glibc 2.26. Closes ticket 24315.
    
      o Minor features (logging):
        - Provide better warnings when the getrandom() syscall fails. Closes
          ticket 24500.
        - Downgrade a pair of log messages that could occur when an exit's
          resolver gave us an unusual (but not forbidden) response. Closes
          ticket 24097.
        - Improve the message we log when re-enabling circuit build timeouts
          after having received a consensus. Closes ticket 20963.
        - Log more circuit information whenever we are about to try to
          package a relay cell on a circuit with a nonexistent n_chan.
          Attempt to diagnose ticket 8185.
        - Improve info-level log identification of particular circuits, to
          help with debugging. Closes ticket 23645.
        - Improve the warning message for specifying a relay by nickname.
          The previous message implied that nickname registration was still
          part of the Tor network design, which it isn't. Closes
          ticket 20488.
        - If the sandbox filter fails to load, suggest to the user that
          their kernel might not support seccomp2. Closes ticket 23090.
    
      o Minor features (onion service, circuit, logging):
        - Improve logging of many callsite in the circuit subsystem to print
          the circuit identifier(s).
        - Log when we cleanup an intro point from a service so we know when
          and for what reason it happened. Closes ticket 23604.
    
      o Minor features (portability):
        - Tor now compiles correctly on arm64 with libseccomp-dev installed.
          (It doesn't yet work with the sandbox enabled.) Closes
          ticket 24424.
        - Check at configure time whether uint8_t is the same type as
          unsigned char. Lots of existing code already makes this
          assumption, and there could be strict aliasing issues if the
          assumption is violated. Closes ticket 22410.
    
      o Minor features (relay):
        - When choosing which circuits can be expired as unused, consider
          circuits from clients even if those clients used regular CREATE
          cells to make them; and do not consider circuits from relays even
          if they were made with CREATE_FAST. Part of ticket 22805.
        - Reject attempts to use relative file paths when RunAsDaemon is
          set. Previously, Tor would accept these, but the directory-
          changing step of RunAsDaemon would give strange and/or confusing
          results. Closes ticket 22731.
    
      o Minor features (relay statistics):
        - Change relay bandwidth reporting stats interval from 4 hours to 24
          hours in order to reduce the efficiency of guard discovery
          attacks. Fixes ticket 23856.
    
      o Minor features (reverted deprecations):
        - The ClientDNSRejectInternalAddresses flag can once again be set in
          non-testing Tor networks, so long as they do not use the default
          directory authorities. This change also removes the deprecation of
          this flag from 0.2.9.2-alpha. Closes ticket 21031.
    
      o Minor features (robustness):
        - Change several fatal assertions when flushing buffers into non-
          fatal assertions, to prevent any recurrence of 23690.
    
      o Minor features (startup, safety):
        - When configured to write a PID file, Tor now exits if it is unable
          to do so. Previously, it would warn and continue. Closes
          ticket 20119.
    
      o Minor features (static analysis):
        - The BUG() macro has been changed slightly so that Coverity no
          longer complains about dead code if the bug is impossible. Closes
          ticket 23054.
    
      o Minor features (testing):
        - Our fuzzing tests now test the encrypted portions of v3 onion
          service descriptors. Implements more of 21509.
        - Add a unit test to make sure that our own generated platform
          string will be accepted by directory authorities. Closes
          ticket 22109.
        - The default chutney network tests now include tests for the v3
          onion service design. Make sure you have the latest version of
          chutney if you want to run these. Closes ticket 22437.
        - Add a unit test to verify that we can parse a hardcoded v2 onion
          service descriptor. Closes ticket 15554.
    
      o Minor bugfixes (address selection):
        - When the fascist_firewall_choose_address_ functions don't find a
          reachable address, set the returned address to the null address
          and port. This is a precautionary measure, because some callers do
          not check the return value. Fixes bug 24736; bugfix
          on 0.2.8.2-alpha.
    
      o Minor bugfixes (bootstrapping):
        - When warning about state file clock skew, report the correct
          direction for the detected skew. Fixes bug 23606; bugfix
          on 0.2.8.1-alpha.
    
      o Minor bugfixes (bridge clients, bootstrap):
        - Retry directory downloads when we get our first bridge descriptor
          during bootstrap or while reconnecting to the network. Keep
          retrying every time we get a bridge descriptor, until we have a
          reachable bridge. Fixes part of bug 24367; bugfix on 0.2.0.3-alpha.
        - Stop delaying bridge descriptor fetches when we have cached bridge
          descriptors. Instead, only delay bridge descriptor fetches when we
          have at least one reachable bridge. Fixes part of bug 24367;
          bugfix on 0.2.0.3-alpha.
        - Stop delaying directory fetches when we have cached bridge
          descriptors. Instead, only delay bridge descriptor fetches when
          all our bridges are definitely unreachable. Fixes part of bug
          24367; bugfix on 0.2.0.3-alpha.
    
      o Minor bugfixes (bridge):
        - Overwrite the bridge address earlier in the process of retrieving
          its descriptor, to make sure we reach it on the configured
          address. Fixes bug 20532; bugfix on 0.2.0.10-alpha.
    
      o Minor bugfixes (build, compilation):
        - Fix a compilation warning when building with zstd support on
          32-bit platforms. Fixes bug 23568; bugfix on 0.3.1.1-alpha. Found
          and fixed by Andreas Stieger.
        - When searching for OpenSSL, don't accept any OpenSSL library that
          lacks TLSv1_1_method(): Tor doesn't build with those versions.
          Additionally, look in /usr/local/opt/openssl, if it's present.
          These changes together repair the default build on OSX systems
          with Homebrew installed. Fixes bug 23602; bugfix on 0.2.7.2-alpha.
        - Fix a signed/unsigned comparison warning introduced by our fix to
          TROVE-2017-009. Fixes bug 24480; bugfix on 0.2.5.16.
        - Fix a memory leak warning in one of the libevent-related
          configuration tests that could occur when manually specifying
          -fsanitize=address. Fixes bug 24279; bugfix on 0.3.0.2-alpha.
          Found and patched by Alex Xu.
        - Fix unused-variable warnings in donna's Curve25519 SSE2 code.
          Fixes bug 22895; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (certificate handling):
        - Fix a time handling bug in Tor certificates set to expire after
          the year 2106. Fixes bug 23055; bugfix on 0.3.0.1-alpha. Found by
          Coverity as CID 1415728.
    
      o Minor bugfixes (client):
        - By default, do not enable storage of client-side DNS values. These
          values were unused by default previously, but they should not have
          been cached at all. Fixes bug 24050; bugfix on 0.2.6.3-alpha.
    
      o Minor bugfixes (client, usability):
        - Refrain from needlessly rejecting SOCKS5-with-hostnames and
          SOCKS4a requests that contain IP address strings, even when
          SafeSocks in enabled, as this prevents user from connecting to
          known IP addresses without relying on DNS for resolving. SafeSocks
          still rejects SOCKS connections that connect to IP addresses when
          those addresses are _not_ encoded as hostnames. Fixes bug 22461;
          bugfix on Tor 0.2.6.2-alpha.
    
      o Minor bugfixes (code correctness):
        - Call htons() in extend_cell_format() for encoding a 16-bit value.
          Previously we used ntohs(), which happens to behave the same on
          all the platforms we support, but which isn't really correct.
          Fixes bug 23106; bugfix on 0.2.4.8-alpha.
        - For defense-in-depth, make the controller's write_escaped_data()
          function robust to extremely long inputs. Fixes bug 19281; bugfix
          on 0.1.1.1-alpha. Reported by Guido Vranken.
        - Fix several places in our codebase where a C compiler would be
          likely to eliminate a check, based on assuming that undefined
          behavior had not happened elsewhere in the code. These cases are
          usually a sign of redundant checking or dubious arithmetic. Found
          by Georg Koppen using the "STACK" tool from Wang, Zeldovich,
          Kaashoek, and Solar-Lezama. Fixes bug 24423; bugfix on various
          Tor versions.
    
      o Minor bugfixes (compression):
        - Handle a pathological case when decompressing Zstandard data when
          the output buffer size is zero. Fixes bug 23551; bugfix
          on 0.3.1.1-alpha.
    
      o Minor bugfixes (consensus expiry):
        - Check for adequate directory information correctly. Previously, Tor
          would reconsider whether it had sufficient directory information
          every 2 minutes. Fixes bug 23091; bugfix on 0.2.0.19-alpha.
    
      o Minor bugfixes (control port, linux seccomp2 sandbox):
        - Avoid a crash when attempting to use the seccomp2 sandbox together
          with the OwningControllerProcess feature. Fixes bug 24198; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (control port, onion services):
        - Report "FAILED" instead of "UPLOAD_FAILED" "FAILED" for the
          HS_DESC event when a service is not able to upload a descriptor.
          Fixes bug 24230; bugfix on 0.2.7.1-alpha.
    
      o Minor bugfixes (directory cache):
        - Recover better from empty or corrupt files in the consensus cache
          directory. Fixes bug 24099; bugfix on 0.3.1.1-alpha.
        - When a consensus diff calculation is only partially successful,
          only record the successful parts as having succeeded. Partial
          success can happen if (for example) one compression method fails
          but the others succeed. Previously we misrecorded all the
          calculations as having succeeded, which would later cause a
          nonfatal assertion failure. Fixes bug 24086; bugfix
          on 0.3.1.1-alpha.
    
      o Minor bugfixes (directory client):
        - On failure to download directory information, delay retry attempts
          by a random amount based on the "decorrelated jitter" algorithm.
          Our previous delay algorithm tended to produce extra-long delays
          too easily. Fixes bug 23816; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (directory protocol):
        - Directory servers now include a "Date:" http header for response
          codes other than 200. Clients starting with a skewed clock and a
          recent consensus were getting "304 Not modified" responses from
          directory authorities, so without the Date header, the client
          would never hear about a wrong clock. Fixes bug 23499; bugfix
          on 0.0.8rc1.
        - Make clients wait for 6 seconds before trying to download a
          consensus from an authority. Fixes bug 17750; bugfix
          on 0.2.8.1-alpha.
    
      o Minor bugfixes (documentation):
        - Document better how to read gcov, and what our gcov postprocessing
          scripts do. Fixes bug 23739; bugfix on 0.2.9.1-alpha.
        - Fix manpage to not refer to the obsolete (and misspelled)
          UseEntryGuardsAsDirectoryGuards parameter in the description of
          NumDirectoryGuards. Fixes bug 23611; bugfix on 0.2.4.8-alpha.
    
      o Minor bugfixes (DoS-resistance):
        - If future code asks if there are any running bridges, without
          checking if bridges are enabled, log a BUG warning rather than
          crashing. Fixes bug 23524; bugfix on 0.3.0.1-alpha.
    
      o Minor bugfixes (entry guards):
        - Tor now updates its guard state when it reads a consensus
          regardless of whether it's missing descriptors. That makes tor use
          its primary guards to fetch descriptors in some edge cases where
          it would previously have used fallback directories. Fixes bug
          23862; bugfix on 0.3.0.1-alpha.
    
      o Minor bugfixes (format strictness):
        - Restrict several data formats to decimal. Previously, the
          BuildTimeHistogram entries in the state file, the "bw=" entries in
          the bandwidth authority file, and the process IDs passed to the
          __OwningControllerProcess option could all be specified in hex or
          octal as well as in decimal. This was not an intentional feature.
          Fixes bug 22802; bugfixes on 0.2.2.1-alpha, 0.2.2.2-alpha,
          and 0.2.2.28-beta.
    
      o Minor bugfixes (heartbeat):
        - If we fail to write a heartbeat message, schedule a retry for the
          minimum heartbeat interval number of seconds in the future. Fixes
          bug 19476; bugfix on 0.2.3.1-alpha.
    
      o Minor bugfixes (logging):
        - Suppress a log notice when relay descriptors arrive. We already
          have a bootstrap progress for this so no need to log notice
          everytime tor receives relay descriptors. Microdescriptors behave
          the same. Fixes bug 23861; bugfix on 0.2.8.2-alpha.
        - Remove duplicate log messages regarding opening non-local
          SocksPorts upon parsing config and opening listeners at startup.
          Fixes bug 4019; bugfix on 0.2.3.3-alpha.
        - Use a more comprehensible log message when telling the user
          they've excluded every running exit node. Fixes bug 7890; bugfix
          on 0.2.2.25-alpha.
        - When logging the number of descriptors we intend to download per
          directory request, do not log a number higher than then the number
          of descriptors we're fetching in total. Fixes bug 19648; bugfix
          on 0.1.1.8-alpha.
        - When warning about a directory owned by the wrong user, log the
          actual name of the user owning the directory. Previously, we'd log
          the name of the process owner twice. Fixes bug 23487; bugfix
          on 0.2.9.1-alpha.
        - Fix some messages on unexpected errors from the seccomp2 library.
          Fixes bug 22750; bugfix on 0.2.5.1-alpha. Patch from "cypherpunks".
        - The tor specification says hop counts are 1-based, so fix two log
          messages that mistakenly logged 0-based hop counts. Fixes bug
          18982; bugfix on 0.2.6.2-alpha and 0.2.4.5-alpha. Patch by teor.
          Credit to Xiaofan Li for reporting this issue.
    
      o Minor bugfixes (logging, relay shutdown, annoyance):
        - When a circuit is marked for close, do not attempt to package any
          cells for channels on that circuit. Previously, we would detect
          this condition lower in the call stack, when we noticed that the
          circuit had no attached channel, and log an annoying message.
          Fixes bug 8185; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (memory safety, defensive programming):
        - Clear the target address when node_get_prim_orport() returns
          early. Fixes bug 23874; bugfix on 0.2.8.2-alpha.
    
      o Minor bugfixes (memory usage):
        - When queuing DESTROY cells on a channel, only queue the circuit-id
          and reason fields: not the entire 514-byte cell. This fix should
          help mitigate any bugs or attacks that fill up these queues, and
          free more RAM for other uses. Fixes bug 24666; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (network layer):
        - When closing a connection via close_connection_immediately(), we
          mark it as "not blocked on bandwidth", to prevent later calls from
          trying to unblock it, and give it permission to read. This fixes a
          backtrace warning that can happen on relays under various
          circumstances. Fixes bug 24167; bugfix on 0.1.0.1-rc.
    
      o Minor bugfixes (onion services):
        - The introduction circuit was being timed out too quickly while
          waiting for the rendezvous circuit to complete. Keep the intro
          circuit around longer instead of timing out and reopening new ones
          constantly. Fixes bug 23681; bugfix on 0.2.4.8-alpha.
        - Rename the consensus parameter "hsdir-interval" to "hsdir_interval"
          so it matches dir-spec.txt. Fixes bug 24262; bugfix
          on 0.3.1.1-alpha.
        - When handling multiple SOCKS request for the same .onion address,
          only fetch the service descriptor once.
        - Avoid a possible double close of a circuit by the intro point on
          error of sending the INTRO_ESTABLISHED cell. Fixes bug 23610;
          bugfix on 0.3.0.1-alpha.
        - When reloading configured onion services, copy all information
          from the old service object. Previously, some data was omitted,
          causing delays in descriptor upload, and other bugs. Fixes bug
          23790; bugfix on 0.2.1.9-alpha.
    
      o Minor bugfixes (path selection):
        - When selecting relays by bandwidth, avoid a rounding error that
          could sometimes cause load to be imbalanced incorrectly.
          Previously, we would always round upwards; now, we round towards
          the nearest integer. This had the biggest effect when a relay's
          weight adjustments should have given it weight 0, but it got
          weight 1 instead. Fixes bug 23318; bugfix on 0.2.4.3-alpha.
        - When calculating the fraction of nodes that have descriptors, and
          all nodes in the network have zero bandwidths, count the number of
          nodes instead. Fixes bug 23318; bugfix on 0.2.4.10-alpha.
        - Actually log the total bandwidth in compute_weighted_bandwidths().
          Fixes bug 24170; bugfix on 0.2.4.3-alpha.
    
      o Minor bugfixes (portability):
        - Stop using the PATH_MAX variable, which is not defined on GNU
          Hurd. Fixes bug 23098; bugfix on 0.3.1.1-alpha.
        - Fix a bug in the bit-counting parts of our timing-wheel code on
          MSVC. (Note that MSVC is still not a supported build platform, due
          to cryptographic timing channel risks.) Fixes bug 24633; bugfix
          on 0.2.9.1-alpha.
    
      o Minor bugfixes (relay):
        - When uploading our descriptor for the first time after startup,
          report the reason for uploading as "Tor just started" rather than
          leaving it blank. Fixes bug 22885; bugfix on 0.2.3.4-alpha.
        - Avoid unnecessary calls to directory_fetches_from_authorities() on
          relays, to prevent spurious address resolutions and descriptor
          rebuilds. This is a mitigation for bug 21789. Fixes bug 23470;
          bugfix on in 0.2.8.1-alpha.
        - Avoid a crash when transitioning from client mode to bridge mode.
          Previously, we would launch the worker threads whenever our
          "public server" mode changed, but not when our "server" mode
          changed. Fixes bug 23693; bugfix on 0.2.6.3-alpha.
    
      o Minor bugfixes (testing):
        - Fix a spurious fuzzing-only use of an uninitialized value. Found
          by Brian Carpenter. Fixes bug 24082; bugfix on 0.3.0.3-alpha.
        - Test that IPv6-only clients can use microdescriptors when running
          "make test-network-all". Requires chutney master 61c28b9 or later.
          Closes ticket 24109.
        - Prevent scripts/test/coverage from attempting to move gcov output
          to the root directory. Fixes bug 23741; bugfix on 0.2.5.1-alpha.
        - Capture and detect several "Result does not fit" warnings in unit
          tests on platforms with 32-bit time_t. Fixes bug 21800; bugfix
          on 0.2.9.3-alpha.
        - Fix additional channelpadding unit test failures by using mocked
          time instead of actual time for all tests. Fixes bug 23608; bugfix
          on 0.3.1.1-alpha.
        - Fix a bug in our fuzzing mock replacement for crypto_pk_checksig(),
          to correctly handle cases where a caller gives it an RSA key of
          under 160 bits. (This is not actually a bug in Tor itself, but
          rather in our fuzzing code.) Fixes bug 24247; bugfix on
          0.3.0.3-alpha. Found by OSS-Fuzz as issue 4177.
        - Fix a broken unit test for the OutboundAddress option: the parsing
          function was never returning an error on failure. Fixes bug 23366;
          bugfix on 0.3.0.3-alpha.
        - Fix a signed-integer overflow in the unit tests for
          dir/download_status_random_backoff, which was untriggered until we
          fixed bug 17750. Fixes bug 22924; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (usability, control port):
        - Stop making an unnecessary routerlist check in NETINFO clock skew
          detection; this was preventing clients from reporting NETINFO clock
          skew to controllers. Fixes bug 23532; bugfix on 0.2.4.4-alpha.
    
      o Code simplification and refactoring:
        - Remove various ways of testing circuits and connections for
          "clientness"; instead, favor channel_is_client(). Part of
          ticket 22805.
        - Extract the code for handling newly-open channels into a separate
          function from the general code to handle channel state
          transitions. This change simplifies our callgraph, reducing the
          size of the largest strongly connected component by roughly a
          factor of two. Closes ticket 22608.
        - Remove dead code for largely unused statistics on the number of
          times we've attempted various public key operations. Fixes bug
          19871; bugfix on 0.1.2.4-alpha. Fix by Isis Lovecruft.
        - Remove several now-obsolete functions for asking about old
          variants directory authority status. Closes ticket 22311; patch
          from "huyvq".
        - Remove some of the code that once supported "Named" and "Unnamed"
          routers. Authorities no longer vote for these flags. Closes
          ticket 22215.
        - Rename the obsolete malleable hybrid_encrypt functions used in TAP
          and old hidden services, to indicate that they aren't suitable for
          new protocols or formats. Closes ticket 23026.
        - Replace our STRUCT_OFFSET() macro with offsetof(). Closes ticket
          22521. Patch from Neel Chauhan.
        - Split the enormous circuit_send_next_onion_skin() function into
          multiple subfunctions. Closes ticket 22804.
        - Split the portions of the buffer.c module that handle particular
          protocols into separate modules. Part of ticket 23149.
        - Use our test macros more consistently, to produce more useful
          error messages when our unit tests fail. Add coccinelle patches to
          allow us to re-check for test macro uses. Closes ticket 22497.
    
      o Deprecated features:
        - The ReachableDirAddresses and ClientPreferIPv6DirPort options are
          now deprecated; they do not apply to relays, and they have had no
          effect on clients since 0.2.8.x. Closes ticket 19704.
        - Deprecate HTTPProxy/HTTPProxyAuthenticator config options. They
          only applies to direct unencrypted HTTP connections to your
          directory server, which your Tor probably isn't using. Closes
          ticket 20575.
    
      o Documentation:
        - Add notes in man page regarding OS support for the various
          scheduler types. Attempt to use less jargon in the scheduler
          section. Closes ticket 24254.
        - Clarify that the Address option is entirely about setting an
          advertised IPv4 address. Closes ticket 18891.
        - Clarify the manpage's use of the term "address" to clarify what
          kind of address is intended. Closes ticket 21405.
        - Document that onion service subdomains are allowed, and ignored.
          Closes ticket 18736.
        - Clarify in the manual that "Sandbox 1" is only supported on Linux
          kernels. Closes ticket 22677.
        - Document all values of PublishServerDescriptor in the manpage.
          Closes ticket 15645.
        - Improve the documentation for the directory port part of the
          DirAuthority line. Closes ticket 20152.
        - Restore documentation for the authorities' "approved-routers"
          file. Closes ticket 21148.
    
      o Removed features:
        - The AllowDotExit option has been removed as unsafe. It has been
          deprecated since 0.2.9.2-alpha. Closes ticket 23426.
        - The ClientDNSRejectInternalAddresses flag can no longer be set on
          non-testing networks. It has been deprecated since 0.2.9.2-alpha.
          Closes ticket 21031.
        - The controller API no longer includes an AUTHDIR_NEWDESCS event:
          nobody was using it any longer. Closes ticket 22377.
    
    
    Changes in version 0.3.1.9 - 2017-12-01:
      Tor 0.3.1.9 backports important security and stability fixes from the
      0.3.2 development series. All Tor users should upgrade to this
      release, or to another of the releases coming out today.
    
      o Major bugfixes (security, backport from 0.3.2.6-alpha):
        - Fix a denial of service bug where an attacker could use a
          malformed directory object to cause a Tor instance to pause while
          OpenSSL would try to read a passphrase from the terminal. (Tor
          instances run without a terminal, which is the case for most Tor
          packages, are not impacted.) Fixes bug 24246; bugfix on every
          version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821.
          Found by OSS-Fuzz as testcase 6360145429790720.
        - Fix a denial of service issue where an attacker could crash a
          directory authority using a malformed router descriptor. Fixes bug
          24245; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010
          and CVE-2017-8820.
        - When checking for replays in the INTRODUCE1 cell data for a
          (legacy) onion service, correctly detect replays in the RSA-
          encrypted part of the cell. We were previously checking for
          replays on the entire cell, but those can be circumvented due to
          the malleability of Tor's legacy hybrid encryption. This fix helps
          prevent a traffic confirmation attack. Fixes bug 24244; bugfix on
          0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009
          and CVE-2017-8819.
    
      o Major bugfixes (security, onion service v2, backport from 0.3.2.6-alpha):
        - Fix a use-after-free error that could crash v2 Tor onion services
          when they failed to open circuits while expiring introduction
          points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is
          also tracked as TROVE-2017-013 and CVE-2017-8823.
    
      o Major bugfixes (security, relay, backport from 0.3.2.6-alpha):
        - When running as a relay, make sure that we never build a path
          through ourselves, even in the case where we have somehow lost the
          version of our descriptor appearing in the consensus. Fixes part
          of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked
          as TROVE-2017-012 and CVE-2017-8822.
        - When running as a relay, make sure that we never choose ourselves
          as a guard. Fixes part of bug 21534; bugfix on 0.3.0.1-alpha. This
          issue is also tracked as TROVE-2017-012 and CVE-2017-8822.
    
      o Major bugfixes (exit relays, DNS, backport from 0.3.2.4-alpha):
        - Fix an issue causing DNS to fail on high-bandwidth exit nodes,
          making them nearly unusable. Fixes bugs 21394 and 18580; bugfix on
          0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for
          identifying and finding a workaround to this bug and to Moritz,
          Arthur Edelstein, and Roger for helping to track it down and
          analyze it.
    
      o Minor features (bridge):
        - Bridges now include notice in their descriptors that they are
          bridges, and notice of their distribution status, based on their
          publication settings. Implements ticket 18329. For more fine-
          grained control of how a bridge is distributed, upgrade to 0.3.2.x
          or later.
    
      o Minor features (directory authority, backport from 0.3.2.6-alpha):
        - Add an IPv6 address for the "bastet" directory authority. Closes
          ticket 24394.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfix (relay address resolution, backport from 0.3.2.1-alpha):
        - Avoid unnecessary calls to directory_fetches_from_authorities() on
          relays, to prevent spurious address resolutions and descriptor
          rebuilds. This is a mitigation for bug 21789. Fixes bug 23470;
          bugfix on in 0.2.8.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.3.2.1-alpha):
        - Fix unused variable warnings in donna's Curve25519 SSE2 code.
          Fixes bug 22895; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (logging, relay shutdown, annoyance, backport from 0.3.2.2-alpha):
        - When a circuit is marked for close, do not attempt to package any
          cells for channels on that circuit. Previously, we would detect
          this condition lower in the call stack, when we noticed that the
          circuit had no attached channel, and log an annoying message.
          Fixes bug 8185; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (onion service, backport from 0.3.2.5-alpha):
        - Rename the consensus parameter "hsdir-interval" to "hsdir_interval"
          so it matches dir-spec.txt. Fixes bug 24262; bugfix
          on 0.3.1.1-alpha.
    
      o Minor bugfixes (relay, crash, backport from 0.3.2.4-alpha):
        - Avoid a crash when transitioning from client mode to bridge mode.
          Previously, we would launch the worker threads whenever our
          "public server" mode changed, but not when our "server" mode
          changed. Fixes bug 23693; bugfix on 0.2.6.3-alpha.
    
    
    Changes in version 0.3.0.13 - 2017-12-01
      Tor 0.3.0.13 backports important security and stability bugfixes from
      later Tor releases. All Tor users should upgrade to this release, or
      to another of the releases coming out today.
    
      Note: the Tor 0.3.0 series will no longer be supported after 26 Jan
      2018. If you need a release with long-term support, please stick with
      the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later.
    
      o Major bugfixes (security, backport from 0.3.2.6-alpha):
        - Fix a denial of service bug where an attacker could use a
          malformed directory object to cause a Tor instance to pause while
          OpenSSL would try to read a passphrase from the terminal. (Tor
          instances run without a terminal, which is the case for most Tor
          packages, are not impacted.) Fixes bug 24246; bugfix on every
          version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821.
          Found by OSS-Fuzz as testcase 6360145429790720.
        - Fix a denial of service issue where an attacker could crash a
          directory authority using a malformed router descriptor. Fixes bug
          24245; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010
          and CVE-2017-8820.
        - When checking for replays in the INTRODUCE1 cell data for a
          (legacy) onion service, correctly detect replays in the RSA-
          encrypted part of the cell. We were previously checking for
          replays on the entire cell, but those can be circumvented due to
          the malleability of Tor's legacy hybrid encryption. This fix helps
          prevent a traffic confirmation attack. Fixes bug 24244; bugfix on
          0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009
          and CVE-2017-8819.
    
      o Major bugfixes (security, onion service v2, backport from 0.3.2.6-alpha):
        - Fix a use-after-free error that could crash v2 Tor onion services
          when they failed to open circuits while expiring introduction
          points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is
          also tracked as TROVE-2017-013 and CVE-2017-8823.
    
      o Major bugfixes (security, relay, backport from 0.3.2.6-alpha):
        - When running as a relay, make sure that we never build a path
          through ourselves, even in the case where we have somehow lost the
          version of our descriptor appearing in the consensus. Fixes part
          of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked
          as TROVE-2017-012 and CVE-2017-8822.
        - When running as a relay, make sure that we never choose ourselves
          as a guard. Fixes part of bug 21534; bugfix on 0.3.0.1-alpha. This
          issue is also tracked as TROVE-2017-012 and CVE-2017-8822.
    
      o Major bugfixes (exit relays, DNS, backport from 0.3.2.4-alpha):
        - Fix an issue causing DNS to fail on high-bandwidth exit nodes,
          making them nearly unusable. Fixes bugs 21394 and 18580; bugfix on
          0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for
          identifying and finding a workaround to this bug and to Moritz,
          Arthur Edelstein, and Roger for helping to track it down and
          analyze it.
    
      o Minor features (security, windows, backport from 0.3.1.1-alpha):
        - Enable a couple of pieces of Windows hardening: one
          (HeapEnableTerminationOnCorruption) that has been on-by-default
          since Windows 8, and unavailable before Windows 7; and one
          (PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION) which we believe doesn't
          affect us, but shouldn't do any harm. Closes ticket 21953.
    
      o Minor features (bridge, backport from 0.3.1.9):
        - Bridges now include notice in their descriptors that they are
          bridges, and notice of their distribution status, based on their
          publication settings. Implements ticket 18329. For more fine-
          grained control of how a bridge is distributed, upgrade to 0.3.2.x
          or later.
    
      o Minor features (directory authority, backport from 0.3.2.6-alpha):
        - Add an IPv6 address for the "bastet" directory authority. Closes
          ticket 24394.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfix (relay address resolution, backport from 0.3.2.1-alpha):
        - Avoid unnecessary calls to directory_fetches_from_authorities() on
          relays, to prevent spurious address resolutions and descriptor
          rebuilds. This is a mitigation for bug 21789. Fixes bug 23470;
          bugfix on in 0.2.8.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.3.2.1-alpha):
        - Fix unused variable warnings in donna's Curve25519 SSE2 code.
          Fixes bug 22895; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (logging, relay shutdown, annoyance, backport from 0.3.2.2-alpha):
        - When a circuit is marked for close, do not attempt to package any
          cells for channels on that circuit. Previously, we would detect
          this condition lower in the call stack, when we noticed that the
          circuit had no attached channel, and log an annoying message.
          Fixes bug 8185; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (relay, crash, backport from 0.3.2.4-alpha):
        - Avoid a crash when transitioning from client mode to bridge mode.
          Previously, we would launch the worker threads whenever our
          "public server" mode changed, but not when our "server" mode
          changed. Fixes bug 23693; bugfix on 0.2.6.3-alpha.
    
      o Minor bugfixes (testing, backport from 0.3.1.6-rc):
        - Fix an undersized buffer in test-memwipe.c. Fixes bug 23291;
          bugfix on 0.2.7.2-alpha. Found and patched by Ties Stuij.
    
    
    Changes in version 0.2.9.14 - 2017-12-01
      Tor 0.3.0.13 backports important security and stability bugfixes from
      later Tor releases. All Tor users should upgrade to this release, or
      to another of the releases coming out today.
    
      o Major bugfixes (exit relays, DNS, backport from 0.3.2.4-alpha):
        - Fix an issue causing DNS to fail on high-bandwidth exit nodes,
          making them nearly unusable. Fixes bugs 21394 and 18580; bugfix on
          0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for
          identifying and finding a workaround to this bug and to Moritz,
          Arthur Edelstein, and Roger for helping to track it down and
          analyze it.
    
      o Major bugfixes (security, backport from 0.3.2.6-alpha):
        - Fix a denial of service bug where an attacker could use a
          malformed directory object to cause a Tor instance to pause while
          OpenSSL would try to read a passphrase from the terminal. (Tor
          instances run without a terminal, which is the case for most Tor
          packages, are not impacted.) Fixes bug 24246; bugfix on every
          version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821.
          Found by OSS-Fuzz as testcase 6360145429790720.
        - Fix a denial of service issue where an attacker could crash a
          directory authority using a malformed router descriptor. Fixes bug
          24245; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010
          and CVE-2017-8820.
        - When checking for replays in the INTRODUCE1 cell data for a
          (legacy) onion service, correctly detect replays in the RSA-
          encrypted part of the cell. We were previously checking for
          replays on the entire cell, but those can be circumvented due to
          the malleability of Tor's legacy hybrid encryption. This fix helps
          prevent a traffic confirmation attack. Fixes bug 24244; bugfix on
          0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009
          and CVE-2017-8819.
    
      o Major bugfixes (security, onion service v2, backport from 0.3.2.6-alpha):
        - Fix a use-after-free error that could crash v2 Tor onion services
          when they failed to open circuits while expiring introduction
          points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is
          also tracked as TROVE-2017-013 and CVE-2017-8823.
    
      o Major bugfixes (security, relay, backport from 0.3.2.6-alpha):
        - When running as a relay, make sure that we never build a path
          through ourselves, even in the case where we have somehow lost the
          version of our descriptor appearing in the consensus. Fixes part
          of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked
          as TROVE-2017-012 and CVE-2017-8822.
    
      o Minor features (bridge, backport from 0.3.1.9):
        - Bridges now include notice in their descriptors that they are
          bridges, and notice of their distribution status, based on their
          publication settings. Implements ticket 18329. For more fine-
          grained control of how a bridge is distributed, upgrade to 0.3.2.x
          or later.
    
      o Minor features (directory authority, backport from 0.3.2.6-alpha):
        - Add an IPv6 address for the "bastet" directory authority. Closes
          ticket 24394.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2
          Country database.
    
      o Minor features (security, windows, backport from 0.3.1.1-alpha):
        - Enable a couple of pieces of Windows hardening: one
          (HeapEnableTerminationOnCorruption) that has been on-by-default
          since Windows 8, and unavailable before Windows 7; and one
          (PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION) which we believe doesn't
          affect us, but shouldn't do any harm. Closes ticket 21953.
    
      o Minor bugfix (relay address resolution, backport from 0.3.2.1-alpha):
        - Avoid unnecessary calls to directory_fetches_from_authorities() on
          relays, to prevent spurious address resolutions and descriptor
          rebuilds. This is a mitigation for bug 21789. Fixes bug 23470;
          bugfix on in 0.2.8.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.3.2.1-alpha):
        - Fix unused variable warnings in donna's Curve25519 SSE2 code.
          Fixes bug 22895; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (logging, relay shutdown, annoyance, backport from 0.3.2.2-alpha):
        - When a circuit is marked for close, do not attempt to package any
          cells for channels on that circuit. Previously, we would detect
          this condition lower in the call stack, when we noticed that the
          circuit had no attached channel, and log an annoying message.
          Fixes bug 8185; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (relay, crash, backport from 0.3.2.4-alpha):
        - Avoid a crash when transitioning from client mode to bridge mode.
          Previously, we would launch the worker threads whenever our
          "public server" mode changed, but not when our "server" mode
          changed. Fixes bug 23693; bugfix on 0.2.6.3-alpha.
    
      o Minor bugfixes (testing, backport from 0.3.1.6-rc):
        - Fix an undersized buffer in test-memwipe.c. Fixes bug 23291;
          bugfix on 0.2.7.2-alpha. Found and patched by Ties Stuij.
    
    
    Changes in version 0.2.8.17 - 2017-12-01
      Tor 0.2.8.17 backports important security and stability bugfixes from
      later Tor releases. All Tor users should upgrade to this release, or
      to another of the releases coming out today.
    
      Note: the Tor 0.2.8 series will no longer be supported after 1 Jan
      2018. If you need a release with long-term support, please upgrade with
      the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later.
    
      o Major bugfixes (security, backport from 0.3.2.6-alpha):
        - Fix a denial of service bug where an attacker could use a
          malformed directory object to cause a Tor instance to pause while
          OpenSSL would try to read a passphrase from the terminal. (Tor
          instances run without a terminal, which is the case for most Tor
          packages, are not impacted.) Fixes bug 24246; bugfix on every
          version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821.
          Found by OSS-Fuzz as testcase 6360145429790720.
        - When checking for replays in the INTRODUCE1 cell data for a
          (legacy) onion service, correctly detect replays in the RSA-
          encrypted part of the cell. We were previously checking for
          replays on the entire cell, but those can be circumvented due to
          the malleability of Tor's legacy hybrid encryption. This fix helps
          prevent a traffic confirmation attack. Fixes bug 24244; bugfix on
          0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009
          and CVE-2017-8819.
    
      o Major bugfixes (security, onion service v2, backport from 0.3.2.6-alpha):
        - Fix a use-after-free error that could crash v2 Tor onion services
          when they failed to open circuits while expiring introduction
          points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is
          also tracked as TROVE-2017-013 and CVE-2017-8823.
    
      o Major bugfixes (security, relay, backport from 0.3.2.6-alpha):
        - When running as a relay, make sure that we never build a path through
          ourselves, even in the case where we have somehow lost the version of
          our descriptor appearing in the consensus. Fixes part of bug 21534;
          bugfix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012
          and CVE-2017-8822.
    
      o Minor features (bridge, backport from 0.3.1.9):
        - Bridges now include notice in their descriptors that they are
          bridges, and notice of their distribution status, based on their
          publication settings. Implements ticket 18329. For more fine-
          grained control of how a bridge is distributed, upgrade to 0.3.2.x
          or later.
    
      o Minor features (directory authority, backport from 0.3.2.6-alpha):
        - Add an IPv6 address for the "bastet" directory authority. Closes
          ticket 24394.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (testing, backport from 0.3.1.6-rc):
        - Fix an undersized buffer in test-memwipe.c. Fixes bug 23291;
          bugfix on 0.2.7.2-alpha. Found and patched by Ties Stuij.
    
    
    Changes in version 0.2.5.16 - 2017-12-01
      Tor 0.2.5.13 backports important security and stability bugfixes from
      later Tor releases. All Tor users should upgrade to this release, or
      to another of the releases coming out today.
    
      Note: the Tor 0.2.5 series will no longer be supported after 1 May
      2018. If you need a release with long-term support, please upgrade to
      the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later.
    
      o Major bugfixes (security, backport from 0.3.2.6-alpha):
        - Fix a denial of service bug where an attacker could use a
          malformed directory object to cause a Tor instance to pause while
          OpenSSL would try to read a passphrase from the terminal. (Tor
          instances run without a terminal, which is the case for most Tor
          packages, are not impacted.) Fixes bug 24246; bugfix on every
          version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821.
          Found by OSS-Fuzz as testcase 6360145429790720.
        - When checking for replays in the INTRODUCE1 cell data for a
          (legacy) onion service, correctly detect replays in the RSA-
          encrypted part of the cell. We were previously checking for
          replays on the entire cell, but those can be circumvented due to
          the malleability of Tor's legacy hybrid encryption. This fix helps
          prevent a traffic confirmation attack. Fixes bug 24244; bugfix on
          0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009
          and CVE-2017-8819.
    
      o Major bugfixes (security, relay, backport from 0.3.2.6-alpha):
        - When running as a relay, make sure that we never build a path
          through ourselves, even in the case where we have somehow lost the
          version of our descriptor appearing in the consensus. Fixes part
          of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked
          as TROVE-2017-012 and CVE-2017-8822.
    
      o Minor features (bridge, backport from 0.3.1.9):
        - Bridges now include notice in their descriptors that they are
          bridges, and notice of their distribution status, based on their
          publication settings. Implements ticket 18329. For more fine-
          grained control of how a bridge is distributed, upgrade to 0.3.2.x
          or later.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.5.15 - 2017-10-25
      Tor 0.2.5.15 backports a collection of bugfixes from later Tor release
      series. It also adds a new directory authority, Bastet.
    
      Note: the Tor 0.2.5 series will no longer be supported after 1 May
      2018. If you need a release with long-term support, please upgrade to
      the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later.
    
      o Directory authority changes:
        - Add "Bastet" as a ninth directory authority to the default list.
          Closes ticket 23910.
        - The directory authority "Longclaw" has changed its IP address.
          Closes ticket 23592.
    
      o Major bugfixes (openbsd, denial-of-service, backport from 0.3.1.5-alpha):
        - Avoid an assertion failure bug affecting our implementation of
          inet_pton(AF_INET6) on certain OpenBSD systems whose strtol()
          handling of "0xx" differs from what we had expected. Fixes bug
          22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (defensive programming, undefined behavior, backport from 0.3.1.4-alpha):
        - Fix a memset() off the end of an array when packing cells. This
          bug should be harmless in practice, since the corrupted bytes are
          still in the same structure, and are always padding bytes,
          ignored, or immediately overwritten, depending on compiler
          behavior. Nevertheless, because the memset()'s purpose is to make
          sure that any other cell-handling bugs can't expose bytes to the
          network, we need to fix it. Fixes bug 22737; bugfix on
          0.2.4.11-alpha. Fixes CID 1401591.
    
      o Build features (backport from 0.3.1.5-alpha):
        - Tor's repository now includes a Travis Continuous Integration (CI)
          configuration file (.travis.yml). This is meant to help new
          developers and contributors who fork Tor to a Github repository be
          better able to test their changes, and understand what we expect
          to pass. To use this new build feature, you must fork Tor to your
          Github account, then go into the "Integrations" menu in the
          repository settings for your fork and enable Travis, then push
          your changes. Closes ticket 22636.
    
    
    Changes in version 0.2.8.16 - 2017-10-25
      Tor 0.2.8.16 backports a collection of bugfixes from later Tor release
      series, including a bugfix for a crash issue that had affected relays
      under memory pressure. It also adds a new directory authority, Bastet.
    
      Note: the Tor 0.2.8 series will no longer be supported after 1 Jan
      2018. If you need a release with long-term support, please stick with
      the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later.
    
      o Directory authority changes:
        - Add "Bastet" as a ninth directory authority to the default list.
          Closes ticket 23910.
        - The directory authority "Longclaw" has changed its IP address.
          Closes ticket 23592.
    
      o Major bugfixes (relay, crash, assertion failure, backport from 0.3.2.2-alpha):
        - Fix a timing-based assertion failure that could occur when the
          circuit out-of-memory handler freed a connection's output buffer.
          Fixes bug 23690; bugfix on 0.2.6.1-alpha.
    
      o Minor features (directory authorities, backport from 0.3.2.2-alpha):
        - Remove longclaw's IPv6 address, as it will soon change. Authority
          IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves
          3/8 directory authorities with IPv6 addresses, but there are also
          52 fallback directory mirrors with IPv6 addresses. Resolves 19760.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.9.13 - 2017-10-25
      Tor 0.2.9.13 backports a collection of bugfixes from later Tor release
      series, including a bugfix for a crash issue that had affected relays
      under memory pressure. It also adds a new directory authority, Bastet.
    
      o Directory authority changes:
        - Add "Bastet" as a ninth directory authority to the default list.
          Closes ticket 23910.
        - The directory authority "Longclaw" has changed its IP address.
          Closes ticket 23592.
    
      o Major bugfixes (relay, crash, assertion failure, backport from 0.3.2.2-alpha):
        - Fix a timing-based assertion failure that could occur when the
          circuit out-of-memory handler freed a connection's output buffer.
          Fixes bug 23690; bugfix on 0.2.6.1-alpha.
    
      o Minor features (directory authorities, backport from 0.3.2.2-alpha):
        - Remove longclaw's IPv6 address, as it will soon change. Authority
          IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves
          3/8 directory authorities with IPv6 addresses, but there are also
          52 fallback directory mirrors with IPv6 addresses. Resolves 19760.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (directory authority, backport from 0.3.1.5-alpha):
        - When a directory authority rejects a descriptor or extrainfo with
          a given digest, mark that digest as undownloadable, so that we do
          not attempt to download it again over and over. We previously
          tried to avoid downloading such descriptors by other means, but we
          didn't notice if we accidentally downloaded one anyway. This
          behavior became problematic in 0.2.7.2-alpha, when authorities
          began pinning Ed25519 keys. Fixes bug 22349; bugfix
          on 0.2.1.19-alpha.
    
      o Minor bugfixes (memory safety, backport from 0.3.2.3-alpha):
        - Clear the address when node_get_prim_orport() returns early.
          Fixes bug 23874; bugfix on 0.2.8.2-alpha.
    
      o Minor bugfixes (Windows service, backport from 0.3.1.6-rc):
        - When running as a Windows service, set the ID of the main thread
          correctly. Failure to do so made us fail to send log messages to
          the controller in 0.2.1.16-rc, slowed down controller event
          delivery in 0.2.7.3-rc and later, and crash with an assertion
          failure in 0.3.1.1-alpha. Fixes bug 23081; bugfix on 0.2.1.6-alpha.
          Patch and diagnosis from "Vort".
    
    
    Changes in version 0.3.0.12 - 2017-10-25
      Tor 0.3.0.12 backports a collection of bugfixes from later Tor release
      series, including a bugfix for a crash issue that had affected relays
      under memory pressure. It also adds a new directory authority, Bastet.
    
      Note: the Tor 0.3.0 series will no longer be supported after 26 Jan
      2018. If you need a release with long-term support, please stick with
      the 0.2.9 series. Otherwise, please upgrade to 0.3.1 or later.
    
      o Directory authority changes:
        - Add "Bastet" as a ninth directory authority to the default list.
          Closes ticket 23910.
        - The directory authority "Longclaw" has changed its IP address.
          Closes ticket 23592.
    
      o Major bugfixes (relay, crash, assertion failure, backport from 0.3.2.2-alpha):
        - Fix a timing-based assertion failure that could occur when the
          circuit out-of-memory handler freed a connection's output buffer.
          Fixes bug 23690; bugfix on 0.2.6.1-alpha.
    
      o Minor features (directory authorities, backport from 0.3.2.2-alpha):
        - Remove longclaw's IPv6 address, as it will soon change. Authority
          IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves
          3/8 directory authorities with IPv6 addresses, but there are also
          52 fallback directory mirrors with IPv6 addresses. Resolves 19760.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (directory authority, backport from 0.3.1.5-alpha):
        - When a directory authority rejects a descriptor or extrainfo with
          a given digest, mark that digest as undownloadable, so that we do
          not attempt to download it again over and over. We previously
          tried to avoid downloading such descriptors by other means, but we
          didn't notice if we accidentally downloaded one anyway. This
          behavior became problematic in 0.2.7.2-alpha, when authorities
          began pinning Ed25519 keys. Fixes bug 22349; bugfix
          on 0.2.1.19-alpha.
    
      o Minor bugfixes (hidden service, relay, backport from 0.3.2.2-alpha):
        - Avoid a possible double close of a circuit by the intro point on
          error of sending the INTRO_ESTABLISHED cell. Fixes bug 23610;
          bugfix on 0.3.0.1-alpha.
    
      o Minor bugfixes (memory safety, backport from 0.3.2.3-alpha):
        - Clear the address when node_get_prim_orport() returns early.
          Fixes bug 23874; bugfix on 0.2.8.2-alpha.
    
      o Minor bugfixes (Windows service, backport from 0.3.1.6-rc):
        - When running as a Windows service, set the ID of the main thread
          correctly. Failure to do so made us fail to send log messages to
          the controller in 0.2.1.16-rc, slowed down controller event
          delivery in 0.2.7.3-rc and later, and crash with an assertion
          failure in 0.3.1.1-alpha. Fixes bug 23081; bugfix on 0.2.1.6-alpha.
          Patch and diagnosis from "Vort".
    
    
    Changes in version 0.3.1.8 - 2017-10-25
      Tor 0.3.1.8 is the second stable release in the 0.3.1 series.
      It includes several bugfixes, including a bugfix for a crash issue
      that had affected relays under memory pressure. It also adds
      a new directory authority, Bastet.
    
      o Directory authority changes:
        - Add "Bastet" as a ninth directory authority to the default list.
          Closes ticket 23910.
        - The directory authority "Longclaw" has changed its IP address.
          Closes ticket 23592.
    
      o Major bugfixes (relay, crash, assertion failure, backport from 0.3.2.2-alpha):
        - Fix a timing-based assertion failure that could occur when the
          circuit out-of-memory handler freed a connection's output buffer.
          Fixes bug 23690; bugfix on 0.2.6.1-alpha.
    
      o Minor features (directory authorities, backport from 0.3.2.2-alpha):
        - Remove longclaw's IPv6 address, as it will soon change. Authority
          IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves
          3/8 directory authorities with IPv6 addresses, but there are also
          52 fallback directory mirrors with IPv6 addresses. Resolves 19760.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (compilation, backport from 0.3.2.2-alpha):
        - Fix a compilation warning when building with zstd support on
          32-bit platforms. Fixes bug 23568; bugfix on 0.3.1.1-alpha. Found
          and fixed by Andreas Stieger.
    
      o Minor bugfixes (compression, backport from 0.3.2.2-alpha):
        - Handle a pathological case when decompressing Zstandard data when
          the output buffer size is zero. Fixes bug 23551; bugfix
          on 0.3.1.1-alpha.
    
      o Minor bugfixes (directory authority, backport from 0.3.2.1-alpha):
        - Remove the length limit on HTTP status lines that authorities can
          send in their replies. Fixes bug 23499; bugfix on 0.3.1.6-rc.
    
      o Minor bugfixes (hidden service, relay, backport from 0.3.2.2-alpha):
        - Avoid a possible double close of a circuit by the intro point on
          error of sending the INTRO_ESTABLISHED cell. Fixes bug 23610;
          bugfix on 0.3.0.1-alpha.
    
      o Minor bugfixes (memory safety, backport from 0.3.2.3-alpha):
        - Clear the address when node_get_prim_orport() returns early.
          Fixes bug 23874; bugfix on 0.2.8.2-alpha.
    
      o Minor bugfixes (unit tests, backport from 0.3.2.2-alpha):
        - Fix additional channelpadding unit test failures by using mocked
          time instead of actual time for all tests. Fixes bug 23608; bugfix
          on 0.3.1.1-alpha.
    
    
    Changes in version 0.2.8.15 - 2017-09-18
      Tor 0.2.8.15 backports a collection of bugfixes from later
      Tor series.
    
      Most significantly, it includes a fix for TROVE-2017-008, a
      security bug that affects hidden services running with the
      SafeLogging option disabled. For more information, see
      https://trac.torproject.org/projects/tor/ticket/23490
    
      Note that Tor 0.2.8.x will no longer be supported after 1 Jan
      2018.  We suggest that you upgrade to the latest stable release if
      possible.  If you can't, we recommend that you upgrade at least to
      0.2.9, which will be supported until 2020.
    
      o Major bugfixes (openbsd, denial-of-service, backport from 0.3.1.5-alpha):
        - Avoid an assertion failure bug affecting our implementation of
          inet_pton(AF_INET6) on certain OpenBSD systems whose strtol()
          handling of "0xx" differs from what we had expected. Fixes bug
          22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007.
    
      o Minor features:
        - Update geoip and geoip6 to the September 6 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (compilation, mingw, backport from 0.3.1.1-alpha):
        - Backport a fix for an "unused variable" warning that appeared
          in some versions of mingw. Fixes bug 22838; bugfix on
          0.2.8.1-alpha.
    
      o Minor bugfixes (defensive programming, undefined behavior, backport from 0.3.1.4-alpha):
        - Fix a memset() off the end of an array when packing cells. This
          bug should be harmless in practice, since the corrupted bytes are
          still in the same structure, and are always padding bytes,
          ignored, or immediately overwritten, depending on compiler
          behavior. Nevertheless, because the memset()'s purpose is to make
          sure that any other cell-handling bugs can't expose bytes to the
          network, we need to fix it. Fixes bug 22737; bugfix on
          0.2.4.11-alpha. Fixes CID 1401591.
    
      o Build features (backport from 0.3.1.5-alpha):
        - Tor's repository now includes a Travis Continuous Integration (CI)
          configuration file (.travis.yml). This is meant to help new
          developers and contributors who fork Tor to a Github repository be
          better able to test their changes, and understand what we expect
          to pass. To use this new build feature, you must fork Tor to your
          Github account, then go into the "Integrations" menu in the
          repository settings for your fork and enable Travis, then push
          your changes. Closes ticket 22636.
    
    
    Changes in version 0.2.9.12 - 2017-09-18
      Tor 0.2.9.12 backports a collection of bugfixes from later
      Tor series.
    
      Most significantly, it includes a fix for TROVE-2017-008, a
      security bug that affects hidden services running with the
      SafeLogging option disabled. For more information, see
      https://trac.torproject.org/projects/tor/ticket/23490
    
      o Major features (security, backport from 0.3.0.2-alpha):
        - Change the algorithm used to decide DNS TTLs on client and server
          side, to better resist DNS-based correlation attacks like the
          DefecTor attack of Greschbach, Pulls, Roberts, Winter, and
          Feamster. Now relays only return one of two possible DNS TTL
          values, and clients are willing to believe DNS TTL values up to 3
          hours long. Closes ticket 19769.
    
      o Major bugfixes (crash, directory connections, backport from 0.3.0.5-rc):
        - Fix a rare crash when sending a begin cell on a circuit whose
          linked directory connection had already been closed. Fixes bug
          21576; bugfix on 0.2.9.3-alpha. Reported by Alec Muffett.
    
      o Major bugfixes (DNS, backport from 0.3.0.2-alpha):
        - Fix a bug that prevented exit nodes from caching DNS records for
          more than 60 seconds. Fixes bug 19025; bugfix on 0.2.4.7-alpha.
    
      o Major bugfixes (linux TPROXY support, backport from 0.3.1.1-alpha):
        - Fix a typo that had prevented TPROXY-based transparent proxying
          from working under Linux. Fixes bug 18100; bugfix on 0.2.6.3-alpha.
          Patch from "d4fq0fQAgoJ".
    
      o Major bugfixes (openbsd, denial-of-service, backport from 0.3.1.5-alpha):
        - Avoid an assertion failure bug affecting our implementation of
          inet_pton(AF_INET6) on certain OpenBSD systems whose strtol()
          handling of "0xx" differs from what we had expected. Fixes bug
          22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007.
    
      o Minor features (code style, backport from 0.3.1.3-alpha):
        - Add "Falls through" comments to our codebase, in order to silence
          GCC 7's -Wimplicit-fallthrough warnings. Patch from Andreas
          Stieger. Closes ticket 22446.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the September 6 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (bandwidth accounting, backport from 0.3.1.1-alpha):
        - Roll over monthly accounting at the configured hour and minute,
          rather than always at 00:00. Fixes bug 22245; bugfix on 0.0.9rc1.
          Found by Andrey Karpov with PVS-Studio.
    
      o Minor bugfixes (compilation, backport from 0.3.1.5-alpha):
        - Suppress -Wdouble-promotion warnings with clang 4.0. Fixes bug 22915;
          bugfix on 0.2.8.1-alpha.
        - Fix warnings when building with libscrypt and openssl scrypt support
          on Clang. Fixes bug 22916; bugfix on 0.2.7.2-alpha.
        - When building with certain versions the mingw C header files, avoid
          float-conversion warnings when calling the C functions isfinite(),
          isnan(), and signbit(). Fixes bug 22801; bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (compilation, backport from 0.3.1.7):
        - Avoid compiler warnings in the unit tests for running tor_sscanf()
          with wide string outputs. Fixes bug 15582; bugfix on 0.2.6.2-alpha.
    
      o Minor bugfixes (compilation, mingw, backport from 0.3.1.1-alpha):
        - Backport a fix for an "unused variable" warning that appeared
          in some versions of mingw. Fixes bug 22838; bugfix on
          0.2.8.1-alpha.
    
      o Minor bugfixes (controller, backport from 0.3.1.7):
        - Do not crash when receiving a HSPOST command with an empty body.
          Fixes part of bug 22644; bugfix on 0.2.7.1-alpha.
        - Do not crash when receiving a POSTDESCRIPTOR command with an
          empty body. Fixes part of bug 22644; bugfix on 0.2.0.1-alpha.
    
      o Minor bugfixes (coverity build support, backport from 0.3.1.5-alpha):
        - Avoid Coverity build warnings related to our BUG() macro. By
          default, Coverity treats BUG() as the Linux kernel does: an
          instant abort(). We need to override that so our BUG() macro
          doesn't prevent Coverity from analyzing functions that use it.
          Fixes bug 23030; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (defensive programming, undefined behavior, backport from 0.3.1.4-alpha):
        - Fix a memset() off the end of an array when packing cells. This
          bug should be harmless in practice, since the corrupted bytes are
          still in the same structure, and are always padding bytes,
          ignored, or immediately overwritten, depending on compiler
          behavior. Nevertheless, because the memset()'s purpose is to make
          sure that any other cell-handling bugs can't expose bytes to the
          network, we need to fix it. Fixes bug 22737; bugfix on
          0.2.4.11-alpha. Fixes CID 1401591.
    
      o Minor bugfixes (file limits, osx, backport from 0.3.1.5-alpha):
        - When setting the maximum number of connections allowed by the OS,
          always allow some extra file descriptors for other files. Fixes
          bug 22797; bugfix on 0.2.0.10-alpha.
    
      o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.1.5-alpha):
        - Avoid a sandbox failure when trying to re-bind to a socket and
          mark it as IPv6-only. Fixes bug 20247; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.1.4-alpha):
        - Permit the fchmod system call, to avoid crashing on startup when
          starting with the seccomp2 sandbox and an unexpected set of
          permissions on the data directory or its contents. Fixes bug
          22516; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (relay, backport from 0.3.0.5-rc):
        - Avoid a double-marked-circuit warning that could happen when we
          receive DESTROY cells under heavy load. Fixes bug 20059; bugfix
          on 0.1.0.1-rc.
    
      o Minor bugfixes (voting consistency, backport from 0.3.1.1-alpha):
        - Reject version numbers with non-numeric prefixes (such as +, -, or
          whitespace). Disallowing whitespace prevents differential version
          parsing between POSIX-based and Windows platforms. Fixes bug 21507
          and part of 21508; bugfix on 0.0.8pre1.
    
      o Build features (backport from 0.3.1.5-alpha):
        - Tor's repository now includes a Travis Continuous Integration (CI)
          configuration file (.travis.yml). This is meant to help new
          developers and contributors who fork Tor to a Github repository be
          better able to test their changes, and understand what we expect
          to pass. To use this new build feature, you must fork Tor to your
          Github account, then go into the "Integrations" menu in the
          repository settings for your fork and enable Travis, then push
          your changes. Closes ticket 22636.
    
    
    Changes in version 0.3.0.11 - 2017-09-18
      Tor 0.3.0.11 backports a collection of bugfixes from Tor the 0.3.1
      series.
    
      Most significantly, it includes a fix for TROVE-2017-008, a
      security bug that affects hidden services running with the
      SafeLogging option disabled. For more information, see
      https://trac.torproject.org/projects/tor/ticket/23490
    
      o Minor features (code style, backport from 0.3.1.7):
        - Add "Falls through" comments to our codebase, in order to silence
          GCC 7's -Wimplicit-fallthrough warnings. Patch from Andreas
          Stieger. Closes ticket 22446.
    
      o Minor features:
        - Update geoip and geoip6 to the September 6 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (compilation, backport from 0.3.1.7):
        - Avoid compiler warnings in the unit tests for calling tor_sscanf()
          with wide string outputs. Fixes bug 15582; bugfix on 0.2.6.2-alpha.
    
      o Minor bugfixes (controller, backport from 0.3.1.7):
        - Do not crash when receiving a HSPOST command with an empty body.
          Fixes part of bug 22644; bugfix on 0.2.7.1-alpha.
        - Do not crash when receiving a POSTDESCRIPTOR command with an empty
          body. Fixes part of bug 22644; bugfix on 0.2.0.1-alpha.
    
      o Minor bugfixes (file limits, osx, backport from 0.3.1.5-alpha):
        - When setting the maximum number of connections allowed by the OS,
          always allow some extra file descriptors for other files. Fixes
          bug 22797; bugfix on 0.2.0.10-alpha.
    
      o Minor bugfixes (logging, relay, backport from 0.3.1.6-rc):
        - Remove a forgotten debugging message when an introduction point
          successfully establishes a hidden service prop224 circuit with
          a client.
        - Change three other log_warn() for an introduction point to
          protocol warnings, because they can be failure from the network
          and are not relevant to the operator. Fixes bug 23078; bugfix on
          0.3.0.1-alpha and 0.3.0.2-alpha.
    
    
    Changes in version 0.3.1.7 - 2017-09-18
      Tor 0.3.1.7 is the first stable release in the 0.3.1 series.
    
      With the 0.3.1 series, Tor now serves and downloads directory
      information in more compact formats, to save on bandwidth overhead. It
      also contains a new padding system to resist netflow-based traffic
      analysis, and experimental support for building parts of Tor in Rust
      (though no parts of Tor are in Rust yet). There are also numerous
      small features, bugfixes on earlier release series, and groundwork for
      the hidden services revamp of 0.3.2.
    
      This release also includes a fix for TROVE-2017-008, a security bug
      that affects hidden services running with the SafeLogging option
      disabled. For more information, see
      https://trac.torproject.org/projects/tor/ticket/23490
    
      Per our stable release policy, we plan to support each stable release
      series for at least the next nine months, or for three months after
      the first stable release of the next series: whichever is longer. If
      you need a release with long-term support, we recommend that you stay
      with the 0.2.9 series.
    
      Below is a list of the changes since 0.3.0. For a list of all
      changes since 0.3.1.6-rc, see the ChangeLog file.
    
      o New dependencies:
        - To build with zstd and lzma support, Tor now requires the
          pkg-config tool at build time.
    
      o Major bugfixes (security, hidden services, loggging):
        - Fix a bug where we could log uninitialized stack when a certain
          hidden service error occurred while SafeLogging was disabled.
          Fixes bug #23490; bugfix on 0.2.7.2-alpha.
          This is also tracked as TROVE-2017-008 and CVE-2017-0380.
    
      o Major features (build system, continuous integration):
        - Tor's repository now includes a Travis Continuous Integration (CI)
          configuration file (.travis.yml). This is meant to help new
          developers and contributors who fork Tor to a Github repository be
          better able to test their changes, and understand what we expect
          to pass. To use this new build feature, you must fork Tor to your
          Github account, then go into the "Integrations" menu in the
          repository settings for your fork and enable Travis, then push
          your changes. Closes ticket 22636.
    
      o Major features (directory protocol):
        - Tor relays and authorities can now serve clients an abbreviated
          version of the consensus document, containing only the changes
          since an older consensus document that the client holds. Clients
          now request these documents when available. When both client and
          server use this new protocol, they will use far less bandwidth (up
          to 94% less) to keep the client's consensus up-to-date. Implements
          proposal 140; closes ticket 13339. Based on work by Daniel Martí.
        - Tor can now compress directory traffic with lzma or with zstd
          compression algorithms, which can deliver better bandwidth
          performance. Because lzma is computationally expensive, it's only
          used for documents that can be compressed once and served many
          times. Support for these algorithms requires that tor is built
          with the libzstd and/or liblzma libraries available. Implements
          proposal 278; closes ticket 21662.
        - Relays now perform the more expensive compression operations, and
          consensus diff generation, in worker threads. This separation
          avoids delaying the main thread when a new consensus arrives.
    
      o Major features (experimental):
        - Tor can now build modules written in Rust. To turn this on, pass
          the "--enable-rust" flag to the configure script. It's not time to
          get excited yet: currently, there is no actual Rust functionality
          beyond some simple glue code, and a notice at startup to tell you
          that Rust is running. Still, we hope that programmers and
          packagers will try building Tor with Rust support, so that we can
          find issues and solve portability problems. Closes ticket 22106.
    
      o Major features (traffic analysis resistance):
        - Connections between clients and relays now send a padding cell in
          each direction every 1.5 to 9.5 seconds (tunable via consensus
          parameters). This padding will not resist specialized
          eavesdroppers, but it should be enough to make many ISPs' routine
          network flow logging less useful in traffic analysis against
          Tor users.
    
          Padding is negotiated using Tor's link protocol, so both relays
          and clients must upgrade for this to take effect. Clients may
          still send padding despite the relay's version by setting
          ConnectionPadding 1 in torrc, and may disable padding by setting
          ConnectionPadding 0 in torrc. Padding may be minimized for mobile
          users with the torrc option ReducedConnectionPadding. Implements
          Proposal 251 and Section 2 of Proposal 254; closes ticket 16861.
        - Relays will publish 24 hour totals of padding and non-padding cell
          counts to their extra-info descriptors, unless PaddingStatistics 0
          is set in torrc. These 24 hour totals are also rounded to
          multiples of 10000.
    
      o Major bugfixes (hidden service, relay, security):
        - Fix a remotely triggerable assertion failure when a hidden service
          handles a malformed BEGIN cell. Fixes bug 22493, tracked as
          TROVE-2017-004 and as CVE-2017-0375; bugfix on 0.3.0.1-alpha.
        - Fix a remotely triggerable assertion failure caused by receiving a
          BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
          22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
          on 0.2.2.1-alpha.
    
      o Major bugfixes (path selection, security):
        - When choosing which guard to use for a circuit, avoid the exit's
          family along with the exit itself. Previously, the new guard
          selection logic avoided the exit, but did not consider its family.
          Fixes bug 22753; bugfix on 0.3.0.1-alpha. Tracked as TROVE-2017-
          006 and CVE-2017-0377.
    
      o Major bugfixes (connection usage):
        - We use NETINFO cells to try to determine if both relays involved
          in a connection will agree on the canonical status of that
          connection. We prefer the connections where this is the case for
          extend cells, and try to close connections where relays disagree
          on their canonical status early. Also, we now prefer the oldest
          valid connection for extend cells. These two changes should reduce
          the number of long-term connections that are kept open between
          relays. Fixes bug 17604; bugfix on 0.2.5.5-alpha.
        - Relays now log hourly statistics (look for
          "channel_check_for_duplicates" lines) on the total number of
          connections to other relays. If the number of connections per
          relay is unexpectedly large, this log message is at notice level.
          Otherwise it is at info.
    
      o Major bugfixes (entry guards):
        - When starting with an old consensus, do not add new entry guards
          unless the consensus is "reasonably live" (under 1 day old). Fixes
          one root cause of bug 22400; bugfix on 0.3.0.1-alpha.
        - Don't block bootstrapping when a primary bridge is offline and we
          can't get its descriptor. Fixes bug 22325; fixes one case of bug
          21969; bugfix on 0.3.0.3-alpha.
    
      o Major bugfixes (linux TPROXY support):
        - Fix a typo that had prevented TPROXY-based transparent proxying
          from working under Linux. Fixes bug 18100; bugfix on 0.2.6.3-alpha.
          Patch from "d4fq0fQAgoJ".
    
      o Major bugfixes (openbsd, denial-of-service):
        - Avoid an assertion failure bug affecting our implementation of
          inet_pton(AF_INET6) on certain OpenBSD systems whose strtol()
          handling of "0xx" differs from what we had expected. Fixes bug
          22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007.
    
      o Major bugfixes (relay, link handshake):
        - When performing the v3 link handshake on a TLS connection, report
          that we have the x509 certificate that we actually used on that
          connection, even if we have changed certificates since that
          connection was first opened. Previously, we would claim to have
          used our most recent x509 link certificate, which would sometimes
          make the link handshake fail. Fixes one case of bug 22460; bugfix
          on 0.2.3.6-alpha.
    
      o Major bugfixes (relays, key management):
        - Regenerate link and authentication certificates whenever the key
          that signs them changes; also, regenerate link certificates
          whenever the signed key changes. Previously, these processes were
          only weakly coupled, and we relays could (for minutes to hours)
          wind up with an inconsistent set of keys and certificates, which
          other relays would not accept. Fixes two cases of bug 22460;
          bugfix on 0.3.0.1-alpha.
        - When sending an Ed25519 signing->link certificate in a CERTS cell,
          send the certificate that matches the x509 certificate that we
          used on the TLS connection. Previously, there was a race condition
          if the TLS context rotated after we began the TLS handshake but
          before we sent the CERTS cell. Fixes a case of bug 22460; bugfix
          on 0.3.0.1-alpha.
    
      o Minor features (security, windows):
        - Enable a couple of pieces of Windows hardening: one
          (HeapEnableTerminationOnCorruption) that has been on-by-default
          since Windows 8, and unavailable before Windows 7; and one
          (PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION) which we believe doesn't
          affect us, but shouldn't do any harm. Closes ticket 21953.
    
      o Minor features (bridge authority):
        - Add "fingerprint" lines to the networkstatus-bridges file produced
          by bridge authorities. Closes ticket 22207.
    
      o Minor features (code style):
        - Add "Falls through" comments to our codebase, in order to silence
          GCC 7's -Wimplicit-fallthrough warnings. Patch from Andreas
          Stieger. Closes ticket 22446.
    
      o Minor features (config options):
        - Allow "%include" directives in torrc configuration files. These
          directives import the settings from other files, or from all the
          files in a directory. Closes ticket 1922. Code by Daniel Pinto.
        - Make SAVECONF return an error when overwriting a torrc that has
          includes. Using SAVECONF with the FORCE option will allow it to
          overwrite torrc even if includes are used. Related to ticket 1922.
        - Add "GETINFO config-can-saveconf" to tell controllers if SAVECONF
          will work without the FORCE option. Related to ticket 1922.
    
      o Minor features (controller):
        - Warn the first time that a controller requests data in the long-
          deprecated 'GETINFO network-status' format. Closes ticket 21703.
    
      o Minor features (defaults):
        - The default value for UseCreateFast is now 0: clients which
          haven't yet received a consensus document will now use a proper
          ntor handshake to talk to their directory servers whenever they
          can. Closes ticket 21407.
        - Onion key rotation and expiry intervals are now defined as a
          network consensus parameter, per proposal 274. The default
          lifetime of an onion key is increased from 7 to 28 days. Old onion
          keys will expire after 7 days by default. This change will make
          consensus diffs much smaller, and save significant bandwidth.
          Closes ticket 21641.
    
      o Minor features (defensive programming):
        - Create a pair of consensus parameters, nf_pad_tor2web and
          nf_pad_single_onion, to disable netflow padding in the consensus
          for non-anonymous connections in case the overhead is high. Closes
          ticket 17857.
    
      o Minor features (diagnostic):
        - Add a stack trace to the bug warnings that can be logged when
          trying to send an outgoing relay cell with n_chan == 0. Diagnostic
          attempt for bug 23105.
        - Add logging messages to try to diagnose a rare bug that seems to
          generate RSA->Ed25519 cross-certificates dated in the 1970s. We
          think this is happening because of incorrect system clocks, but
          we'd like to know for certain. Diagnostic for bug 22466.
        - Avoid an assertion failure, and log a better error message, when
          unable to remove a file from the consensus cache on Windows.
          Attempts to mitigate and diagnose bug 22752.
    
      o Minor features (directory authority):
        - Improve the message that authorities report to relays that present
          RSA/Ed25519 keypairs that conflict with previously pinned keys.
          Closes ticket 22348.
    
      o Minor features (directory cache, consensus diff):
        - Add a new MaxConsensusAgeForDiffs option to allow directory cache
          operators with low-resource environments to adjust the number of
          consensuses they'll store and generate diffs from. Most cache
          operators should leave it unchanged. Helps to work around
          bug 22883.
    
      o Minor features (fallback directory list):
        - Update the fallback directory mirror whitelist and blacklist based
          on operator emails. Closes task 21121.
        - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in
          December 2016 (of which ~126 were still functional) with a list of
          151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May
          2017. Resolves ticket 21564.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the September 6 2017 Maxmind GeoLite2
          Country database.
    
      o Minor features (hidden services, logging):
        - Log a message when a hidden service descriptor has fewer
          introduction points than specified in
          HiddenServiceNumIntroductionPoints. Closes tickets 21598.
        - Log a message when a hidden service reaches its introduction point
          circuit limit, and when that limit is reset. Follow up to ticket
          21594; closes ticket 21622.
        - Warn user if multiple entries in EntryNodes and at least one
          HiddenService are used together. Pinning EntryNodes along with a
          hidden service can be possibly harmful; for instance see ticket
          14917 or 21155. Closes ticket 21155.
    
      o Minor features (linux seccomp2 sandbox):
        - We now have a document storage backend compatible with the Linux
          seccomp2 sandbox. This backend is used for consensus documents and
          diffs between them; in the long term, we'd like to use it for
          unparseable directory material too. Closes ticket 21645
        - Increase the maximum allowed size passed to mprotect(PROT_WRITE)
          from 1MB to 16MB. This was necessary with the glibc allocator in
          order to allow worker threads to allocate more memory -- which in
          turn is necessary because of our new use of worker threads for
          compression. Closes ticket 22096.
    
      o Minor features (logging):
        - Log files are no longer created world-readable by default.
          (Previously, most distributors would store the logs in a non-
          world-readable location to prevent inappropriate access. This
          change is an extra precaution.) Closes ticket 21729; patch
          from toralf.
    
      o Minor features (performance):
        - Our Keccak (SHA-3) implementation now accesses memory more
          efficiently, especially on little-endian systems. Closes
          ticket 21737.
        - Add an O(1) implementation of channel_find_by_global_id(), to
          speed some controller functions.
    
      o Minor features (relay, configuration):
        - The MyFamily option may now be repeated as many times as desired,
          for relays that want to configure large families. Closes ticket
          4998; patch by Daniel Pinto.
    
      o Minor features (relay, performance):
        - Always start relays with at least two worker threads, to prevent
          priority inversion on slow tasks. Part of the fix for bug 22883.
        - Allow background work to be queued with different priorities, so
          that a big pile of slow low-priority jobs will not starve out
          higher priority jobs. This lays the groundwork for a fix for
          bug 22883.
    
      o Minor features (safety):
        - Add an explicit check to extrainfo_parse_entry_from_string() for
          NULL inputs. We don't believe this can actually happen, but it may
          help silence a warning from the Clang analyzer. Closes
          ticket 21496.
    
      o Minor features (testing):
        - Add more tests for compression backend initialization. Closes
          ticket 22286.
        - Add a "--disable-memory-sentinels" feature to help with fuzzing.
          When Tor is compiled with this option, we disable a number of
          redundant memory-safety failsafes that are intended to stop bugs
          from becoming security issues. This makes it easier to hunt for
          bugs that would be security issues without the failsafes turned
          on. Closes ticket 21439.
        - Add a general event-tracing instrumentation support to Tor. This
          subsystem will enable developers and researchers to add fine-
          grained instrumentation to their Tor instances, for use when
          examining Tor network performance issues. There are no trace
          events yet, and event-tracing is off by default unless enabled at
          compile time. Implements ticket 13802.
        - Improve our version parsing tests: add tests for typical version
          components, add tests for invalid versions, including numeric
          range and non-numeric prefixes. Unit tests 21278, 21450, and
          21507. Partially implements 21470.
    
      o Minor bugfixes (bandwidth accounting):
        - Roll over monthly accounting at the configured hour and minute,
          rather than always at 00:00. Fixes bug 22245; bugfix on 0.0.9rc1.
          Found by Andrey Karpov with PVS-Studio.
    
      o Minor bugfixes (code correctness):
        - Accurately identify client connections by their lack of peer
          authentication. This means that we bail out earlier if asked to
          extend to a client. Follow-up to 21407. Fixes bug 21406; bugfix
          on 0.2.4.23.
    
      o Minor bugfixes (compilation warnings):
        - Suppress -Wdouble-promotion warnings with clang 4.0. Fixes bug
          22915; bugfix on 0.2.8.1-alpha.
        - Fix warnings when building with libscrypt and openssl scrypt
          support on Clang. Fixes bug 22916; bugfix on 0.2.7.2-alpha.
        - When building with certain versions of the mingw C header files,
          avoid float-conversion warnings when calling the C functions
          isfinite(), isnan(), and signbit(). Fixes bug 22801; bugfix
          on 0.2.8.1-alpha.
    
      o Minor bugfixes (compilation):
        - Avoid compiler warnings in the unit tests for calling tor_sscanf()
          with wide string outputs. Fixes bug 15582; bugfix on 0.2.6.2-alpha.
    
      o Minor bugfixes (compression):
        - When spooling compressed data to an output buffer, don't try to
          spool more data when there is no more data to spool and we are not
          trying to flush the input. Previously, we would sometimes launch
          compression requests with nothing to do, which interferes with our
          22672 checks. Fixes bug 22719; bugfix on 0.2.0.16-alpha.
    
      o Minor bugfixes (configuration):
        - Do not crash when starting with LearnCircuitBuildTimeout 0. Fixes
          bug 22252; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (connection lifespan):
        - Allow more control over how long TLS connections are kept open:
          unify CircuitIdleTimeout and PredictedPortsRelevanceTime into a
          single option called CircuitsAvailableTimeout. Also, allow the
          consensus to control the default values for both this preference
          and the lifespan of relay-to-relay connections. Fixes bug 17592;
          bugfix on 0.2.5.5-alpha.
        - Increase the initial circuit build timeout testing frequency, to
          help ensure that ReducedConnectionPadding clients finish learning
          a timeout before their orconn would expire. The initial testing
          rate was set back in the days of TAP and before the Tor Browser
          updater, when we had to be much more careful about new clients
          making lots of circuits. With this change, a circuit build timeout
          is learned in about 15-20 minutes, instead of 100-120 minutes.
    
      o Minor bugfixes (controller):
        - Do not crash when receiving a HSPOST command with an empty body.
          Fixes part of bug 22644; bugfix on 0.2.7.1-alpha.
        - Do not crash when receiving a POSTDESCRIPTOR command with an empty
          body. Fixes part of bug 22644; bugfix on 0.2.0.1-alpha.
        - GETINFO onions/current and onions/detached no longer respond with
          551 on empty lists. Fixes bug 21329; bugfix on 0.2.7.1-alpha.
        - Trigger HS descriptor events on the control port when the client
          fails to pick a hidden service directory for a hidden service.
          This can happen if all the hidden service directories are in
          ExcludeNodes, or they have all been queried within the last 15
          minutes. Fixes bug 22042; bugfix on 0.2.5.2-alpha.
    
      o Minor bugfixes (correctness):
        - Avoid undefined behavior when parsing IPv6 entries from the geoip6
          file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.
    
      o Minor bugfixes (coverity build support):
        - Avoid Coverity build warnings related to our BUG() macro. By
          default, Coverity treats BUG() as the Linux kernel does: an
          instant abort(). We need to override that so our BUG() macro
          doesn't prevent Coverity from analyzing functions that use it.
          Fixes bug 23030; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (defensive programming):
        - Detect and break out of infinite loops in our compression code. We
          don't think that any such loops exist now, but it's best to be
          safe. Closes ticket 22672.
        - Fix a memset() off the end of an array when packing cells. This
          bug should be harmless in practice, since the corrupted bytes are
          still in the same structure, and are always padding bytes,
          ignored, or immediately overwritten, depending on compiler
          behavior. Nevertheless, because the memset()'s purpose is to make
          sure that any other cell-handling bugs can't expose bytes to the
          network, we need to fix it. Fixes bug 22737; bugfix on
          0.2.4.11-alpha. Fixes CID 1401591.
    
      o Minor bugfixes (directory authority):
        - When a directory authority rejects a descriptor or extrainfo with
          a given digest, mark that digest as undownloadable, so that we do
          not attempt to download it again over and over. We previously
          tried to avoid downloading such descriptors by other means, but we
          didn't notice if we accidentally downloaded one anyway. This
          behavior became problematic in 0.2.7.2-alpha, when authorities
          began pinning Ed25519 keys. Fixes bug 22349; bugfix
          on 0.2.1.19-alpha.
        - When rejecting a router descriptor for running an obsolete version
          of Tor without ntor support, warn about the obsolete tor version,
          not the missing ntor key. Fixes bug 20270; bugfix on 0.2.9.3-alpha.
        - Prevent the shared randomness subsystem from asserting when
          initialized by a bridge authority with an incomplete configuration
          file. Fixes bug 21586; bugfix on 0.2.9.8.
    
      o Minor bugfixes (error reporting, windows):
        - When formatting Windows error messages, use the English format to
          avoid codepage issues. Fixes bug 22520; bugfix on 0.1.2.8-alpha.
          Patch from "Vort".
    
      o Minor bugfixes (exit-side DNS):
        - Fix an untriggerable assertion that checked the output of a
          libevent DNS error, so that the assertion actually behaves as
          expected. Fixes bug 22244; bugfix on 0.2.0.20-rc. Found by Andrey
          Karpov using PVS-Studio.
    
      o Minor bugfixes (fallback directories):
        - Make the usage example in updateFallbackDirs.py actually work, and
          explain what it does. Fixes bug 22270; bugfix on 0.3.0.3-alpha.
        - Decrease the guard flag average required to be a fallback. This
          allows us to keep relays that have their guard flag removed when
          they restart. Fixes bug 20913; bugfix on 0.2.8.1-alpha.
        - Decrease the minimum number of fallbacks to 100. Fixes bug 20913;
          bugfix on 0.2.8.1-alpha.
        - Make sure fallback directory mirrors have the same address, port,
          and relay identity key for at least 30 days before they are
          selected. Fixes bug 20913; bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (file limits, osx):
        - When setting the maximum number of connections allowed by the OS,
          always allow some extra file descriptors for other files. Fixes
          bug 22797; bugfix on 0.2.0.10-alpha.
    
      o Minor bugfixes (hidden services):
        - Increase the number of circuits that a service is allowed to
          open over a specific period of time. The value was lower than it
          should be (8 vs 12) in the normal case of 3 introduction points.
          Fixes bug 22159; bugfix on 0.3.0.5-rc.
        - Fix a BUG warning during HSv3 descriptor decoding that could be
          cause by a specially crafted descriptor. Fixes bug 23233; bugfix
          on 0.3.0.1-alpha. Bug found by "haxxpop".
        - Stop printing a cryptic warning when a hidden service gets a
          request to connect to a virtual port that it hasn't configured.
          Fixes bug 16706; bugfix on 0.2.6.3-alpha.
        - Simplify hidden service descriptor creation by using an existing
          flag to check if an introduction point is established. Fixes bug
          21599; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (link handshake):
        - Lower the lifetime of the RSA->Ed25519 cross-certificate to six
          months, and regenerate it when it is within one month of expiring.
          Previously, we had generated this certificate at startup with a
          ten-year lifetime, but that could lead to weird behavior when Tor
          was started with a grossly inaccurate clock. Mitigates bug 22466;
          mitigation on 0.3.0.1-alpha.
    
      o Minor bugfixes (linux seccomp2 sandbox):
        - Avoid a sandbox failure when trying to re-bind to a socket and
          mark it as IPv6-only. Fixes bug 20247; bugfix on 0.2.5.1-alpha.
        - Permit the fchmod system call, to avoid crashing on startup when
          starting with the seccomp2 sandbox and an unexpected set of
          permissions on the data directory or its contents. Fixes bug
          22516; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (logging):
        - When decompressing, do not warn if we fail to decompress using a
          compression method that we merely guessed. Fixes part of bug
          22670; bugfix on 0.1.1.14-alpha.
        - When decompressing, treat mismatch between content-encoding and
          actual compression type as a protocol warning. Fixes part of bug
          22670; bugfix on 0.1.1.9-alpha.
        - Downgrade "assigned_to_cpuworker failed" message to info-level
          severity. In every case that can reach it, either a better warning
          has already been logged, or no warning is warranted. Fixes bug
          22356; bugfix on 0.2.6.3-alpha.
        - Log a better message when a directory authority replies to an
          upload with an unexpected status code. Fixes bug 11121; bugfix
          on 0.1.0.1-rc.
        - Downgrade a log statement about unexpected relay cells from "bug"
          to "protocol warning", because there is at least one use case
          where it can be triggered by a buggy tor implementation. Fixes bug
          21293; bugfix on 0.1.1.14-alpha.
    
      o Minor bugfixes (logging, relay):
        - Remove a forgotten debugging message when an introduction point
          successfully establishes a hidden service prop224 circuit with
          a client.
        - Change three other log_warn() for an introduction point to
          protocol warnings, because they can be failure from the network
          and are not relevant to the operator. Fixes bug 23078; bugfix on
          0.3.0.1-alpha and 0.3.0.2-alpha.
    
      o Minor bugfixes (relay):
        - Inform the geoip and rephist modules about all requests, even on
          relays that are only fetching microdescriptors. Fixes a bug
          related to 21585; bugfix on 0.3.0.1-alpha.
    
      o Minor bugfixes (memory leaks):
        - Fix a small memory leak at exit from the backtrace handler code.
          Fixes bug 21788; bugfix on 0.2.5.2-alpha. Patch from Daniel Pinto.
        - When directory authorities reject a router descriptor due to
          keypinning, free the router descriptor rather than leaking the
          memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha.
        - Fix a small memory leak when validating a configuration that uses
          two or more AF_UNIX sockets for the same port type. Fixes bug
          23053; bugfix on 0.2.6.3-alpha. This is CID 1415725.
    
      o Minor bugfixes (process behavior):
        - When exiting because of an error, always exit with a nonzero exit
          status. Previously, we would fail to report an error in our exit
          status in cases related to __OwningControllerProcess failure,
          lockfile contention, and Ed25519 key initialization. Fixes bug
          22720; bugfix on versions 0.2.1.6-alpha, 0.2.2.28-beta, and
          0.2.7.2-alpha respectively. Reported by "f55jwk4f"; patch
          from "huyvq".
    
      o Minor bugfixes (robustness, error handling):
        - Improve our handling of the cases where OpenSSL encounters a
          memory error while encoding keys and certificates. We haven't
          observed these errors in the wild, but if they do happen, we now
          detect and respond better. Fixes bug 19418; bugfix on all versions
          of Tor. Reported by Guido Vranken.
    
      o Minor bugfixes (testing):
        - Fix an undersized buffer in test-memwipe.c. Fixes bug 23291;
          bugfix on 0.2.7.2-alpha. Found and patched by Ties Stuij.
        - Use unbuffered I/O for utility functions around the
          process_handle_t type. This fixes unit test failures reported on
          OpenBSD and FreeBSD. Fixes bug 21654; bugfix on 0.2.3.1-alpha.
        - Make display of captured unit test log messages consistent. Fixes
          bug 21510; bugfix on 0.2.9.3-alpha.
        - Make test-network.sh always call chutney's test-network.sh.
          Previously, this only worked on systems which had bash installed,
          due to some bash-specific code in the script. Fixes bug 19699;
          bugfix on 0.3.0.4-rc. Follow-up to ticket 21581.
        - Fix a memory leak in the link-handshake/certs_ok_ed25519 test.
          Fixes bug 22803; bugfix on 0.3.0.1-alpha.
        - The unit tests now pass on systems where localhost is misconfigured
          to some IPv4 address other than 127.0.0.1. Fixes bug 6298; bugfix
          on 0.0.9pre2.
    
      o Minor bugfixes (voting consistency):
        - Reject version numbers with non-numeric prefixes (such as +, -, or
          whitespace). Disallowing whitespace prevents differential version
          parsing between POSIX-based and Windows platforms. Fixes bug 21507
          and part of 21508; bugfix on 0.0.8pre1.
    
      o Minor bugfixes (Windows service):
        - When running as a Windows service, set the ID of the main thread
          correctly. Failure to do so made us fail to send log messages to
          the controller in 0.2.1.16-rc, slowed down controller event
          delivery in 0.2.7.3-rc and later, and crash with an assertion
          failure in 0.3.1.1-alpha. Fixes bug 23081; bugfix on 0.2.1.6-alpha.
          Patch and diagnosis from "Vort".
    
      o Minor bugfixes (windows, relay):
        - Resolve "Failure from drain_fd: No error" warnings on Windows
          relays. Fixes bug 21540; bugfix on 0.2.6.3-alpha.
    
      o Code simplification and refactoring:
        - Break up the 630-line function connection_dir_client_reached_eof()
          into a dozen smaller functions. This change should help
          maintainability and readability of the client directory code.
        - Isolate our use of the openssl headers so that they are only
          included from our crypto wrapper modules, and from tests that
          examine those modules' internals. Closes ticket 21841.
        - Simplify our API to launch directory requests, making it more
          extensible and less error-prone. Now it's easier to add extra
          headers to directory requests. Closes ticket 21646.
        - Our base64 decoding functions no longer overestimate the output
          space that they need when parsing unpadded inputs. Closes
          ticket 17868.
        - Remove unused "ROUTER_ADDED_NOTIFY_GENERATOR" internal value.
          Resolves ticket 22213.
        - The logic that directory caches use to spool request to clients,
          serving them one part at a time so as not to allocate too much
          memory, has been refactored for consistency. Previously there was
          a separate spooling implementation per type of spoolable data. Now
          there is one common spooling implementation, with extensible data
          types. Closes ticket 21651.
        - Tor's compression module now supports multiple backends. Part of
          the implementation for proposal 278; closes ticket 21663.
    
      o Documentation:
        - Add a manpage description for the key-pinning-journal file. Closes
          ticket 22347.
        - Correctly note that bandwidth accounting values are stored in the
          state file, and the bw_accounting file is now obsolete. Closes
          ticket 16082.
        - Document more of the files in the Tor data directory, including
          cached-extrainfo, secret_onion_key{,_ntor}.old, hidserv-stats,
          approved-routers, sr-random, and diff-cache. Found while fixing
          ticket 22347.
        - Clarify the manpage for the (deprecated) torify script. Closes
          ticket 6892.
        - Clarify the behavior of the KeepAliveIsolateSOCKSAuth sub-option.
          Closes ticket 21873.
        - Correct documentation about the default DataDirectory value.
          Closes ticket 21151.
        - Document the default behavior of NumEntryGuards and
          NumDirectoryGuards correctly. Fixes bug 21715; bugfix
          on 0.3.0.1-alpha.
        - Document key=value pluggable transport arguments for Bridge lines
          in torrc. Fixes bug 20341; bugfix on 0.2.5.1-alpha.
        - Note that bandwidth-limiting options don't affect TCP headers or
          DNS. Closes ticket 17170.
    
      o Removed features (configuration options, all in ticket 22060):
        - These configuration options are now marked Obsolete, and no longer
          have any effect: AllowInvalidNodes, AllowSingleHopCircuits,
          AllowSingleHopExits, ExcludeSingleHopRelays, FastFirstHopPK,
          TLSECGroup, WarnUnsafeSocks. They were first marked as deprecated
          in 0.2.9.2-alpha and have now been removed. The previous default
          behavior is now always chosen; the previous (less secure) non-
          default behavior is now unavailable.
        - CloseHSClientCircuitsImmediatelyOnTimeout and
          CloseHSServiceRendCircuitsImmediatelyOnTimeout were deprecated in
          0.2.9.2-alpha and now have been removed. HS circuits never close
          on circuit build timeout; they have a longer timeout period.
        - {Control,DNS,Dir,Socks,Trans,NATD,OR}ListenAddress were deprecated
          in 0.2.9.2-alpha and now have been removed. Use the ORPort option
          (and others) to configure listen-only and advertise-only addresses.
    
      o Removed features (tools):
        - We've removed the tor-checkkey tool from src/tools. Long ago, we
          used it to help people detect RSA keys that were generated by
          versions of Debian affected by CVE-2008-0166. But those keys have
          been out of circulation for ages, and this tool is no longer
          required. Closes ticket 21842.
    
    
    Changes in version 0.3.0.10 - 2017-08-02
       Tor 0.3.0.10 backports a collection of small-to-medium bugfixes
       from the current Tor alpha series. OpenBSD users and TPROXY users
       should upgrade; others are probably okay sticking with 0.3.0.9.
    
      o Major features (build system, continuous integration, backport from 0.3.1.5-alpha):
        - Tor's repository now includes a Travis Continuous Integration (CI)
          configuration file (.travis.yml). This is meant to help new
          developers and contributors who fork Tor to a Github repository be
          better able to test their changes, and understand what we expect
          to pass. To use this new build feature, you must fork Tor to your
          Github account, then go into the "Integrations" menu in the
          repository settings for your fork and enable Travis, then push
          your changes. Closes ticket 22636.
    
      o Major bugfixes (linux TPROXY support, backport from 0.3.1.1-alpha):
        - Fix a typo that had prevented TPROXY-based transparent proxying
          from working under Linux. Fixes bug 18100; bugfix on 0.2.6.3-alpha.
          Patch from "d4fq0fQAgoJ".
    
      o Major bugfixes (openbsd, denial-of-service, backport from 0.3.1.5-alpha):
        - Avoid an assertion failure bug affecting our implementation of
          inet_pton(AF_INET6) on certain OpenBSD systems whose strtol()
          handling of "0xbar" differs from what we had expected. Fixes bug
          22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007.
    
      o Minor features (backport from 0.3.1.5-alpha):
        - Update geoip and geoip6 to the July 4 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (bandwidth accounting, backport from 0.3.1.2-alpha):
        - Roll over monthly accounting at the configured hour and minute,
          rather than always at 00:00. Fixes bug 22245; bugfix on 0.0.9rc1.
          Found by Andrey Karpov with PVS-Studio.
    
      o Minor bugfixes (compilation warnings, backport from 0.3.1.5-alpha):
        - Suppress -Wdouble-promotion warnings with clang 4.0. Fixes bug 22915;
          bugfix on 0.2.8.1-alpha.
        - Fix warnings when building with libscrypt and openssl scrypt
          support on Clang. Fixes bug 22916; bugfix on 0.2.7.2-alpha.
        - When building with certain versions of the mingw C header files,
          avoid float-conversion warnings when calling the C functions
          isfinite(), isnan(), and signbit(). Fixes bug 22801; bugfix
          on 0.2.8.1-alpha.
    
      o Minor bugfixes (compilation, mingw, backport from 0.3.1.1-alpha):
        - Backport a fix for an "unused variable" warning that appeared
          in some versions of mingw. Fixes bug 22838; bugfix on
          0.2.8.1-alpha.
    
      o Minor bugfixes (coverity build support, backport from 0.3.1.5-alpha):
        - Avoid Coverity build warnings related to our BUG() macro. By
          default, Coverity treats BUG() as the Linux kernel does: an
          instant abort(). We need to override that so our BUG() macro
          doesn't prevent Coverity from analyzing functions that use it.
          Fixes bug 23030; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (directory authority, backport from 0.3.1.1-alpha):
        - When rejecting a router descriptor for running an obsolete version
          of Tor without ntor support, warn about the obsolete tor version,
          not the missing ntor key. Fixes bug 20270; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.1.5-alpha):
        - Avoid a sandbox failure when trying to re-bind to a socket and
          mark it as IPv6-only. Fixes bug 20247; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (unit tests, backport from 0.3.1.5-alpha)
        - Fix a memory leak in the link-handshake/certs_ok_ed25519 test.
          Fixes bug 22803; bugfix on 0.3.0.1-alpha.
    
    
    Changes in version 0.3.0.9 - 2017-06-29
      Tor 0.3.0.9 fixes a path selection bug that would allow a client
      to use a guard that was in the same network family as a chosen exit
      relay. This is a security regression; all clients running earlier
      versions of 0.3.0.x or 0.3.1.x should upgrade to 0.3.0.9 or
      0.3.1.4-alpha.
    
      This release also backports several other bugfixes from the 0.3.1.x
      series.
    
      o Major bugfixes (path selection, security, backport from 0.3.1.4-alpha):
        - When choosing which guard to use for a circuit, avoid the exit's
          family along with the exit itself. Previously, the new guard
          selection logic avoided the exit, but did not consider its family.
          Fixes bug 22753; bugfix on 0.3.0.1-alpha. Tracked as TROVE-2017-
          006 and CVE-2017-0377.
    
      o Major bugfixes (entry guards, backport from 0.3.1.1-alpha):
        - Don't block bootstrapping when a primary bridge is offline and we
          can't get its descriptor. Fixes bug 22325; fixes one case of bug
          21969; bugfix on 0.3.0.3-alpha.
    
      o Major bugfixes (entry guards, backport from 0.3.1.4-alpha):
        - When starting with an old consensus, do not add new entry guards
          unless the consensus is "reasonably live" (under 1 day old). Fixes
          one root cause of bug 22400; bugfix on 0.3.0.1-alpha.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the June 8 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (voting consistency, backport from 0.3.1.1-alpha):
        - Reject version numbers with non-numeric prefixes (such as +, -, or
          whitespace). Disallowing whitespace prevents differential version
          parsing between POSIX-based and Windows platforms. Fixes bug 21507
          and part of 21508; bugfix on 0.0.8pre1.
    
      o Minor bugfixes (linux seccomp2 sandbox, backport from 0.3.1.4-alpha):
        - Permit the fchmod system call, to avoid crashing on startup when
          starting with the seccomp2 sandbox and an unexpected set of
          permissions on the data directory or its contents. Fixes bug
          22516; bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (defensive programming, backport from 0.3.1.4-alpha):
        - Fix a memset() off the end of an array when packing cells. This
          bug should be harmless in practice, since the corrupted bytes are
          still in the same structure, and are always padding bytes,
          ignored, or immediately overwritten, depending on compiler
          behavior. Nevertheless, because the memset()'s purpose is to make
          sure that any other cell-handling bugs can't expose bytes to the
          network, we need to fix it. Fixes bug 22737; bugfix on
          0.2.4.11-alpha. Fixes CID 1401591.
    
    
    Changes in version 0.3.0.8 - 2017-06-08
      Tor 0.3.0.8 fixes a pair of bugs that would allow an attacker to
      remotely crash a hidden service with an assertion failure. Anyone
      running a hidden service should upgrade to this version, or to some
      other version with fixes for TROVE-2017-004 and TROVE-2017-005.
    
      Tor 0.3.0.8 also includes fixes for several key management bugs
      that sometimes made relays unreliable, as well as several other
      bugfixes described below.
    
      o Major bugfixes (hidden service, relay, security, backport
        from 0.3.1.3-alpha):
        - Fix a remotely triggerable assertion failure when a hidden service
          handles a malformed BEGIN cell. Fixes bug 22493, tracked as
          TROVE-2017-004 and as CVE-2017-0375; bugfix on 0.3.0.1-alpha.
        - Fix a remotely triggerable assertion failure caused by receiving a
          BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
          22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
          on 0.2.2.1-alpha.
    
      o Major bugfixes (relay, link handshake, backport from 0.3.1.3-alpha):
        - When performing the v3 link handshake on a TLS connection, report
          that we have the x509 certificate that we actually used on that
          connection, even if we have changed certificates since that
          connection was first opened. Previously, we would claim to have
          used our most recent x509 link certificate, which would sometimes
          make the link handshake fail. Fixes one case of bug 22460; bugfix
          on 0.2.3.6-alpha.
    
      o Major bugfixes (relays, key management, backport from 0.3.1.3-alpha):
        - Regenerate link and authentication certificates whenever the key
          that signs them changes; also, regenerate link certificates
          whenever the signed key changes. Previously, these processes were
          only weakly coupled, and we relays could (for minutes to hours)
          wind up with an inconsistent set of keys and certificates, which
          other relays would not accept. Fixes two cases of bug 22460;
          bugfix on 0.3.0.1-alpha.
        - When sending an Ed25519 signing->link certificate in a CERTS cell,
          send the certificate that matches the x509 certificate that we
          used on the TLS connection. Previously, there was a race condition
          if the TLS context rotated after we began the TLS handshake but
          before we sent the CERTS cell. Fixes a case of bug 22460; bugfix
          on 0.3.0.1-alpha.
    
      o Major bugfixes (hidden service v3, backport from 0.3.1.1-alpha):
        - Stop rejecting v3 hidden service descriptors because their size
          did not match an old padding rule. Fixes bug 22447; bugfix on
          tor-0.3.0.1-alpha.
    
      o Minor features (fallback directory list, backport from 0.3.1.3-alpha):
        - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in
          December 2016 (of which ~126 were still functional) with a list of
          151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May
          2017. Resolves ticket 21564.
    
      o Minor bugfixes (configuration, backport from 0.3.1.1-alpha):
        - Do not crash when starting with LearnCircuitBuildTimeout 0. Fixes
          bug 22252; bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (correctness, backport from 0.3.1.3-alpha):
        - Avoid undefined behavior when parsing IPv6 entries from the geoip6
          file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.
    
      o Minor bugfixes (link handshake, backport from 0.3.1.3-alpha):
        - Lower the lifetime of the RSA->Ed25519 cross-certificate to six
          months, and regenerate it when it is within one month of expiring.
          Previously, we had generated this certificate at startup with a
          ten-year lifetime, but that could lead to weird behavior when Tor
          was started with a grossly inaccurate clock. Mitigates bug 22466;
          mitigation on 0.3.0.1-alpha.
    
      o Minor bugfixes (memory leak, directory authority, backport from
        0.3.1.2-alpha):
        - When directory authorities reject a router descriptor due to
          keypinning, free the router descriptor rather than leaking the
          memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha.
    
    
    Changes in version 0.2.9.11 - 2017-06-08
      Tor 0.2.9.11 backports a fix for a bug that would allow an attacker to
      remotely crash a hidden service with an assertion failure. Anyone
      running a hidden service should upgrade to this version, or to some
      other version with fixes for TROVE-2017-005. (Versions before 0.3.0
      are not affected by TROVE-2017-004.)
    
      Tor 0.2.9.11 also backports fixes for several key management bugs
      that sometimes made relays unreliable, as well as several other
      bugfixes described below.
    
      o Major bugfixes (hidden service, relay, security, backport
        from 0.3.1.3-alpha):
        - Fix a remotely triggerable assertion failure caused by receiving a
          BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
          22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
          on 0.2.2.1-alpha.
    
      o Major bugfixes (relay, link handshake, backport from 0.3.1.3-alpha):
        - When performing the v3 link handshake on a TLS connection, report
          that we have the x509 certificate that we actually used on that
          connection, even if we have changed certificates since that
          connection was first opened. Previously, we would claim to have
          used our most recent x509 link certificate, which would sometimes
          make the link handshake fail. Fixes one case of bug 22460; bugfix
          on 0.2.3.6-alpha.
    
      o Minor features (fallback directory list, backport from 0.3.1.3-alpha):
        - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in
          December 2016 (of which ~126 were still functional) with a list of
          151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May
          2017. Resolves ticket 21564.
    
      o Minor features (future-proofing, backport from 0.3.0.7):
        - Tor no longer refuses to download microdescriptors or descriptors if
          they are listed as "published in the future".  This change will
          eventually allow us to stop listing meaningful "published" dates
          in microdescriptor consensuses, and thereby allow us to reduce the
          resources required to download consensus diffs by over 50%.
          Implements part of ticket 21642; implements part of proposal 275.
    
      o Minor features (directory authorities, backport from 0.3.0.4-rc)
        - Directory authorities now reject relays running versions
          0.2.9.1-alpha through 0.2.9.4-alpha, because those relays
          suffer from bug 20499 and don't keep their consensus cache
          up-to-date. Resolves ticket 20509.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (control port, backport from 0.3.0.6):
        - The GETINFO extra-info/digest/<digest> command was broken because
          of a wrong base16 decode return value check, introduced when
          refactoring that API. Fixes bug 22034; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (correctness, backport from 0.3.1.3-alpha):
        - Avoid undefined behavior when parsing IPv6 entries from the geoip6
          file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.
    
      o Minor bugfixes (Linux seccomp2 sandbox, backport from 0.3.0.7):
        - The getpid() system call is now permitted under the Linux seccomp2
          sandbox, to avoid crashing with versions of OpenSSL (and other
          libraries) that attempt to learn the process's PID by using the
          syscall rather than the VDSO code. Fixes bug 21943; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (memory leak, directory authority, backport
        from 0.3.1.2-alpha):
        - When directory authorities reject a router descriptor due to
          keypinning, free the router descriptor rather than leaking the
          memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha.
    
    Changes in version 0.2.8.14 - 2017-06-08
      Tor 0.2.7.8 backports a fix for a bug that would allow an attacker to
      remotely crash a hidden service with an assertion failure. Anyone
      running a hidden service should upgrade to this version, or to some
      other version with fixes for TROVE-2017-005.  (Versions before 0.3.0
      are not affected by TROVE-2017-004.)
    
      o Major bugfixes (hidden service, relay, security):
        - Fix a remotely triggerable assertion failure caused by receiving a
          BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
          22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
          on 0.2.2.1-alpha.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
          Country database.
    
      o Minor features (fallback directory list, backport from 0.3.1.3-alpha):
        - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in
          December 2016 (of which ~126 were still functional) with a list of
          151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May
          2017. Resolves ticket 21564.
    
      o Minor bugfixes (correctness):
        - Avoid undefined behavior when parsing IPv6 entries from the geoip6
          file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.
    
    Changes in version 0.2.7.8 - 2017-06-08
      Tor 0.2.7.8 backports a fix for a bug that would allow an attacker to
      remotely crash a hidden service with an assertion failure. Anyone
      running a hidden service should upgrade to this version, or to some
      other version with fixes for TROVE-2017-005.  (Versions before 0.3.0
      are not affected by TROVE-2017-004.)
    
      o Major bugfixes (hidden service, relay, security):
        - Fix a remotely triggerable assertion failure caused by receiving a
          BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
          22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
          on 0.2.2.1-alpha.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (correctness):
        - Avoid undefined behavior when parsing IPv6 entries from the geoip6
          file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.
    
    
    Changes in version 0.2.6.12 - 2017-06-08
      Tor 0.2.6.12 backports a fix for a bug that would allow an attacker to
      remotely crash a hidden service with an assertion failure. Anyone
      running a hidden service should upgrade to this version, or to some
      other version with fixes for TROVE-2017-005.  (Versions before 0.3.0
      are not affected by TROVE-2017-004.)
    
      o Major bugfixes (hidden service, relay, security):
        - Fix a remotely triggerable assertion failure caused by receiving a
          BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
          22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
          on 0.2.2.1-alpha.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (correctness):
        - Avoid undefined behavior when parsing IPv6 entries from the geoip6
          file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.
    
    Changes in version 0.2.5.14 - 2017-06-08
      Tor 0.2.5.14 backports a fix for a bug that would allow an attacker to
      remotely crash a hidden service with an assertion failure. Anyone
      running a hidden service should upgrade to this version, or to some
      other version with fixes for TROVE-2017-005.  (Versions before 0.3.0
      are not affected by TROVE-2017-004.)
    
      o Major bugfixes (hidden service, relay, security):
        - Fix a remotely triggerable assertion failure caused by receiving a
          BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
          22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
          on 0.2.2.1-alpha.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (correctness):
        - Avoid undefined behavior when parsing IPv6 entries from the geoip6
          file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.
    
    Changes in version 0.2.4.29 - 2017-06-08
      Tor 0.2.4.29 backports a fix for a bug that would allow an attacker to
      remotely crash a hidden service with an assertion failure. Anyone
      running a hidden service should upgrade to this version, or to some
      other version with fixes for TROVE-2017-005.  (Versions before 0.3.0
      are not affected by TROVE-2017-004.)
    
      o Major bugfixes (hidden service, relay, security):
        - Fix a remotely triggerable assertion failure caused by receiving a
          BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
          22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
          on 0.2.2.1-alpha.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (correctness):
        - Avoid undefined behavior when parsing IPv6 entries from the geoip6
          file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.
    
    
    Changes in version 0.3.0.7 - 2017-05-15
      Tor 0.3.0.7 fixes a medium-severity security bug in earlier versions
      of Tor 0.3.0.x, where an attacker could cause a Tor relay process
      to exit. Relays running earlier versions of Tor 0.3.0.x should upgrade;
      clients are not affected.
    
      o Major bugfixes (hidden service directory, security):
        - Fix an assertion failure in the hidden service directory code, which
          could be used by an attacker to remotely cause a Tor relay process to
          exit. Relays running earlier versions of Tor 0.3.0.x should upgrade.
          should upgrade. This security issue is tracked as TROVE-2017-002.
          Fixes bug 22246; bugfix on 0.3.0.1-alpha.
    
      o Minor features:
        - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
          Country database.
    
      o Minor features (future-proofing):
        - Tor no longer refuses to download microdescriptors or descriptors
          if they are listed as "published in the future". This change will
          eventually allow us to stop listing meaningful "published" dates
          in microdescriptor consensuses, and thereby allow us to reduce the
          resources required to download consensus diffs by over 50%.
          Implements part of ticket 21642; implements part of proposal 275.
    
      o Minor bugfixes (Linux seccomp2 sandbox):
        - The getpid() system call is now permitted under the Linux seccomp2
          sandbox, to avoid crashing with versions of OpenSSL (and other
          libraries) that attempt to learn the process's PID by using the
          syscall rather than the VDSO code. Fixes bug 21943; bugfix
          on 0.2.5.1-alpha.
    
    
    Changes in version 0.3.0.6 - 2017-04-26
      Tor 0.3.0.6 is the first stable release of the Tor 0.3.0 series.
    
      With the 0.3.0 series, clients and relays now use Ed25519 keys to
      authenticate their link connections to relays, rather than the old
      RSA1024 keys that they used before. (Circuit crypto has been
      Curve25519-authenticated since 0.2.4.8-alpha.) We have also replaced
      the guard selection and replacement algorithm to behave more robustly
      in the presence of unreliable networks, and to resist guard-
      capture attacks.
    
      This series also includes numerous other small features and bugfixes,
      along with more groundwork for the upcoming hidden-services revamp.
    
      Per our stable release policy, we plan to support the Tor 0.3.0
      release series for at least the next nine months, or for three months
      after the first stable release of the 0.3.1 series: whichever is
      longer. If you need a release with long-term support, we recommend
      that you stay with the 0.2.9 series.
    
      Below are the changes since 0.2.9.10. For a list of only the changes
      since 0.3.0.5-rc, see the ChangeLog file.
    
      o Major features (directory authority, security):
        - The default for AuthDirPinKeys is now 1: directory authorities
          will reject relays where the RSA identity key matches a previously
          seen value, but the Ed25519 key has changed. Closes ticket 18319.
    
      o Major features (guard selection algorithm):
        - Tor's guard selection algorithm has been redesigned from the
          ground up, to better support unreliable networks and restrictive
          sets of entry nodes, and to better resist guard-capture attacks by
          hostile local networks. Implements proposal 271; closes
          ticket 19877.
    
      o Major features (next-generation hidden services):
        - Relays can now handle v3 ESTABLISH_INTRO cells as specified by
          prop224 aka "Next Generation Hidden Services". Service and clients
          don't use this functionality yet. Closes ticket 19043. Based on
          initial code by Alec Heifetz.
        - Relays now support the HSDir version 3 protocol, so that they can
          can store and serve v3 descriptors. This is part of the next-
          generation onion service work detailed in proposal 224. Closes
          ticket 17238.
    
      o Major features (protocol, ed25519 identity keys):
        - Clients now support including Ed25519 identity keys in the EXTEND2
          cells they generate. By default, this is controlled by a consensus
          parameter, currently disabled. You can turn this feature on for
          testing by setting ExtendByEd25519ID in your configuration. This
          might make your traffic appear different than the traffic
          generated by other users, however. Implements part of ticket
          15056; part of proposal 220.
        - Relays now understand requests to extend to other relays by their
          Ed25519 identity keys. When an Ed25519 identity key is included in
          an EXTEND2 cell, the relay will only extend the circuit if the
          other relay can prove ownership of that identity. Implements part
          of ticket 15056; part of proposal 220.
        - Relays now use Ed25519 to prove their Ed25519 identities and to
          one another, and to clients. This algorithm is faster and more
          secure than the RSA-based handshake we've been doing until now.
          Implements the second big part of proposal 220; Closes
          ticket 15055.
    
      o Major features (security):
        - Change the algorithm used to decide DNS TTLs on client and server
          side, to better resist DNS-based correlation attacks like the
          DefecTor attack of Greschbach, Pulls, Roberts, Winter, and
          Feamster. Now relays only return one of two possible DNS TTL
          values, and clients are willing to believe DNS TTL values up to 3
          hours long. Closes ticket 19769.
    
      o Major bugfixes (client, onion service, also in 0.2.9.9):
        - Fix a client-side onion service reachability bug, where multiple
          socks requests to an onion service (or a single slow request)
          could cause us to mistakenly mark some of the service's
          introduction points as failed, and we cache that failure so
          eventually we run out and can't reach the service. Also resolves a
          mysterious "Remote server sent bogus reason code 65021" log
          warning. The bug was introduced in ticket 17218, where we tried to
          remember the circuit end reason as a uint16_t, which mangled
          negative values. Partially fixes bug 21056 and fixes bug 20307;
          bugfix on 0.2.8.1-alpha.
    
      o Major bugfixes (crash, directory connections):
        - Fix a rare crash when sending a begin cell on a circuit whose
          linked directory connection had already been closed. Fixes bug
          21576; bugfix on 0.2.9.3-alpha. Reported by Alec Muffett.
    
      o Major bugfixes (directory authority):
        - During voting, when marking a relay as a probable sybil, do not
          clear its BadExit flag: sybils can still be bad in other ways
          too. (We still clear the other flags.) Fixes bug 21108; bugfix
          on 0.2.0.13-alpha.
    
      o Major bugfixes (DNS):
        - Fix a bug that prevented exit nodes from caching DNS records for
          more than 60 seconds. Fixes bug 19025; bugfix on 0.2.4.7-alpha.
    
      o Major bugfixes (IPv6 Exits):
        - Stop rejecting all IPv6 traffic on Exits whose exit policy rejects
          any IPv6 addresses. Instead, only reject a port over IPv6 if the
          exit policy rejects that port on more than an IPv6 /16 of
          addresses. This bug was made worse by 17027 in 0.2.8.1-alpha,
          which rejected a relay's own IPv6 address by default. Fixes bug
          21357; bugfix on commit 004f3f4e53 in 0.2.4.7-alpha.
    
      o Major bugfixes (parsing):
        - Fix an integer underflow bug when comparing malformed Tor
          versions. This bug could crash Tor when built with
          --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
          0.2.9.8, which were built with -ftrapv by default. In other cases
          it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
          on 0.0.8pre1. Found by OSS-Fuzz.
        - When parsing a malformed content-length field from an HTTP
          message, do not read off the end of the buffer. This bug was a
          potential remote denial-of-service attack against Tor clients and
          relays. A workaround was released in October 2016, to prevent this
          bug from crashing Tor. This is a fix for the underlying issue,
          which should no longer matter (if you applied the earlier patch).
          Fixes bug 20894; bugfix on 0.2.0.16-alpha. Bug found by fuzzing
          using AFL (http://lcamtuf.coredump.cx/afl/).
    
      o Major bugfixes (scheduler):
        - Actually compare circuit policies in ewma_cmp_cmux(). This bug
          caused the channel scheduler to behave more or less randomly,
          rather than preferring channels with higher-priority circuits.
          Fixes bug 20459; bugfix on 0.2.6.2-alpha.
    
      o Major bugfixes (security, also in 0.2.9.9):
        - Downgrade the "-ftrapv" option from "always on" to "only on when
          --enable-expensive-hardening is provided." This hardening option,
          like others, can turn survivable bugs into crashes--and having it
          on by default made a (relatively harmless) integer overflow bug
          into a denial-of-service bug. Fixes bug 21278 (TROVE-2017-001);
          bugfix on 0.2.9.1-alpha.
    
      o Minor feature (client):
        - Enable IPv6 traffic on the SocksPort by default. To disable this,
          a user will have to specify "NoIPv6Traffic". Closes ticket 21269.
    
      o Minor feature (fallback scripts):
        - Add a check_existing mode to updateFallbackDirs.py, which checks
          if fallbacks in the hard-coded list are working. Closes ticket
          20174. Patch by haxxpop.
    
      o Minor feature (protocol versioning):
        - Add new protocol version for proposal 224. HSIntro now advertises
          version "3-4" and HSDir version "1-2". Fixes ticket 20656.
    
      o Minor features (ciphersuite selection):
        - Allow relays to accept a wider range of ciphersuites, including
          chacha20-poly1305 and AES-CCM. Closes the other part of 15426.
        - Clients now advertise a list of ciphersuites closer to the ones
          preferred by Firefox. Closes part of ticket 15426.
    
      o Minor features (controller):
        - Add "GETINFO sr/current" and "GETINFO sr/previous" keys, to expose
          shared-random values to the controller. Closes ticket 19925.
        - When HSFETCH arguments cannot be parsed, say "Invalid argument"
          rather than "unrecognized." Closes ticket 20389; patch from
          Ivan Markin.
    
      o Minor features (controller, configuration):
        - Each of the *Port options, such as SocksPort, ORPort, ControlPort,
          and so on, now comes with a __*Port variant that will not be saved
          to the torrc file by the controller's SAVECONF command. This
          change allows TorBrowser to set up a single-use domain socket for
          each time it launches Tor. Closes ticket 20956.
        - The GETCONF command can now query options that may only be
          meaningful in context-sensitive lists. This allows the controller
          to query the mixed SocksPort/__SocksPort style options introduced
          in feature 20956. Implements ticket 21300.
    
      o Minor features (diagnostic, directory client):
        - Warn when we find an unexpected inconsistency in directory
          download status objects. Prevents some negative consequences of
          bug 20593.
    
      o Minor features (directory authorities):
        - Directory authorities now reject descriptors that claim to be
          malformed versions of Tor. Helps prevent exploitation of
          bug 21278.
        - Reject version numbers with components that exceed INT32_MAX.
          Otherwise 32-bit and 64-bit platforms would behave inconsistently.
          Fixes bug 21450; bugfix on 0.0.8pre1.
    
      o Minor features (directory authority):
        - Add a new authority-only AuthDirTestEd25519LinkKeys option (on by
          default) to control whether authorities should try to probe relays
          by their Ed25519 link keys. This option will go away in a few
          releases--unless we encounter major trouble in our ed25519 link
          protocol rollout, in which case it will serve as a safety option.
    
      o Minor features (directory cache):
        - Relays and bridges will now refuse to serve the consensus they
          have if they know it is too old for a client to use. Closes
          ticket 20511.
    
      o Minor features (ed25519 link handshake):
        - Advertise support for the ed25519 link handshake using the
          subprotocol-versions mechanism, so that clients can tell which
          relays can identity themselves by Ed25519 ID. Closes ticket 20552.
    
      o Minor features (entry guards):
        - Add UseEntryGuards to TEST_OPTIONS_DEFAULT_VALUES in order to not
          break regression tests.
        - Require UseEntryGuards when UseBridges is set, in order to make
          sure bridges aren't bypassed. Resolves ticket 20502.
    
      o Minor features (fallback directories):
        - Allow 3 fallback relays per operator, which is safe now that we
          are choosing 200 fallback relays. Closes ticket 20912.
        - Annotate updateFallbackDirs.py with the bandwidth and consensus
          weight for each candidate fallback. Closes ticket 20878.
        - Display the relay fingerprint when downloading consensuses from
          fallbacks. Closes ticket 20908.
        - Exclude relays affected by bug 20499 from the fallback list.
          Exclude relays from the fallback list if they are running versions
          known to be affected by bug 20499, or if in our tests they deliver
          a stale consensus (i.e. one that expired more than 24 hours ago).
          Closes ticket 20539.
        - Make it easier to change the output sort order of fallbacks.
          Closes ticket 20822.
        - Reduce the minimum fallback bandwidth to 1 MByte/s. Part of
          ticket 18828.
        - Require fallback directories to have the same address and port for
          7 days (now that we have enough relays with this stability).
          Relays whose OnionOO stability timer is reset on restart by bug
          18050 should upgrade to Tor 0.2.8.7 or later, which has a fix for
          this issue. Closes ticket 20880; maintains short-term fix
          in 0.2.8.2-alpha.
        - Require fallbacks to have flags for 90% of the time (weighted
          decaying average), rather than 95%. This allows at least 73% of
          clients to bootstrap in the first 5 seconds without contacting an
          authority. Part of ticket 18828.
        - Select 200 fallback directories for each release. Closes
          ticket 20881.
    
      o Minor features (fingerprinting resistance, authentication):
        - Extend the length of RSA keys used for TLS link authentication to
          2048 bits. (These weren't used for forward secrecy; for forward
          secrecy, we used P256.) Closes ticket 13752.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the April 4 2017 Maxmind GeoLite2
          Country database.
    
      o Minor features (geoip, also in 0.2.9.9):
        - Update geoip and geoip6 to the January 4 2017 Maxmind GeoLite2
          Country database.
    
      o Minor features (infrastructure):
        - Implement smartlist_add_strdup() function. Replaces the use of
          smartlist_add(sl, tor_strdup(str)). Closes ticket 20048.
    
      o Minor features (linting):
        - Enhance the changes file linter to warn on Tor versions that are
          prefixed with "tor-". Closes ticket 21096.
    
      o Minor features (logging):
        - In several places, describe unset ed25519 keys as "<unset>",
          rather than the scary "AAAAAAAA...AAA". Closes ticket 21037.
    
      o Minor features (portability, compilation):
        - Autoconf now checks to determine if OpenSSL structures are opaque,
          instead of explicitly checking for OpenSSL version numbers. Part
          of ticket 21359.
        - Support building with recent LibreSSL code that uses opaque
          structures. Closes ticket 21359.
    
      o Minor features (relay):
        - We now allow separation of exit and relay traffic to different
          source IP addresses, using the OutboundBindAddressExit and
          OutboundBindAddressOR options respectively. Closes ticket 17975.
          Written by Michael Sonntag.
    
      o Minor features (reliability, crash):
        - Try better to detect problems in buffers where they might grow (or
          think they have grown) over 2 GB in size. Diagnostic for
          bug 21369.
    
      o Minor features (testing):
        - During 'make test-network-all', if tor logs any warnings, ask
          chutney to output them. Requires a recent version of chutney with
          the 21572 patch. Implements 21570.
    
      o Minor bugfix (control protocol):
        - The reply to a "GETINFO config/names" request via the control
          protocol now spells the type "Dependent" correctly. This is a
          breaking change in the control protocol. (The field seems to be
          ignored by the most common known controllers.) Fixes bug 18146;
          bugfix on 0.1.1.4-alpha.
        - The GETINFO extra-info/digest/<digest> command was broken because
          of a wrong base16 decode return value check, introduced when
          refactoring that API. Fixes bug 22034; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfix (logging):
        - Don't recommend the use of Tor2web in non-anonymous mode.
          Recommending Tor2web is a bad idea because the client loses all
          anonymity. Tor2web should only be used in specific cases by users
          who *know* and understand the issues. Fixes bug 21294; bugfix
          on 0.2.9.3-alpha.
    
      o Minor bugfixes (bug resilience):
        - Fix an unreachable size_t overflow in base64_decode(). Fixes bug
          19222; bugfix on 0.2.0.9-alpha. Found by Guido Vranken; fixed by
          Hans Jerry Illikainen.
    
      o Minor bugfixes (build):
        - Replace obsolete Autoconf macros with their modern equivalent and
          prevent similar issues in the future. Fixes bug 20990; bugfix
          on 0.1.0.1-rc.
    
      o Minor bugfixes (certificate expiration time):
        - Avoid using link certificates that don't become valid till some
          time in the future. Fixes bug 21420; bugfix on 0.2.4.11-alpha
    
      o Minor bugfixes (client):
        - Always recover from failures in extend_info_from_node(), in an
          attempt to prevent any recurrence of bug 21242. Fixes bug 21372;
          bugfix on 0.2.3.1-alpha.
        - When clients that use bridges start up with a cached consensus on
          disk, they were ignoring it and downloading a new one. Now they
          use the cached one. Fixes bug 20269; bugfix on 0.2.3.12-alpha.
    
      o Minor bugfixes (code correctness):
        - Repair a couple of (unreachable or harmless) cases of the risky
          comparison-by-subtraction pattern that caused bug 21278.
    
      o Minor bugfixes (config):
        - Don't assert on startup when trying to get the options list and
          LearnCircuitBuildTimeout is set to 0: we are currently parsing the
          options so of course they aren't ready yet. Fixes bug 21062;
          bugfix on 0.2.9.3-alpha.
    
      o Minor bugfixes (configuration):
        - Accept non-space whitespace characters after the severity level in
          the `Log` option. Fixes bug 19965; bugfix on 0.2.1.1-alpha.
        - Support "TByte" and "TBytes" units in options given in bytes.
          "TB", "terabyte(s)", "TBit(s)" and "terabit(s)" were already
          supported. Fixes bug 20622; bugfix on 0.2.0.14-alpha.
    
      o Minor bugfixes (configure, autoconf):
        - Rename the configure option --enable-expensive-hardening to
          --enable-fragile-hardening. Expensive hardening makes the tor
          daemon abort when some kinds of issues are detected. Thus, it
          makes tor more at risk of remote crashes but safer against RCE or
          heartbleed bug category. We now try to explain this issue in a
          message from the configure script. Fixes bug 21290; bugfix
          on 0.2.5.4-alpha.
    
      o Minor bugfixes (consensus weight):
        - Add new consensus method that initializes bw weights to 1 instead
          of 0. This prevents a zero weight from making it all the way to
          the end (happens in small testing networks) and causing an error.
          Fixes bug 14881; bugfix on 0.2.2.17-alpha.
    
      o Minor bugfixes (crash prevention):
        - Fix an (currently untriggerable, but potentially dangerous) crash
          bug when base32-encoding inputs whose sizes are not a multiple of
          5. Fixes bug 21894; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (dead code):
        - Remove a redundant check for PidFile changes at runtime in
          options_transition_allowed(): this check is already performed
          regardless of whether the sandbox is active. Fixes bug 21123;
          bugfix on 0.2.5.4-alpha.
    
      o Minor bugfixes (descriptors):
        - Correctly recognise downloaded full descriptors as valid, even
          when using microdescriptors as circuits. This affects clients with
          FetchUselessDescriptors set, and may affect directory authorities.
          Fixes bug 20839; bugfix on 0.2.3.2-alpha.
    
      o Minor bugfixes (directory mirrors):
        - Allow relays to use directory mirrors without a DirPort: these
          relays need to be contacted over their ORPorts using a begindir
          connection. Fixes one case of bug 20711; bugfix on 0.2.8.2-alpha.
        - Clarify the message logged when a remote relay is unexpectedly
          missing an ORPort or DirPort: users were confusing this with a
          local port. Fixes another case of bug 20711; bugfix
          on 0.2.8.2-alpha.
    
      o Minor bugfixes (directory system):
        - Bridges and relays now use microdescriptors (like clients do)
          rather than old-style router descriptors. Now bridges will blend
          in with clients in terms of the circuits they build. Fixes bug
          6769; bugfix on 0.2.3.2-alpha.
        - Download all consensus flavors, descriptors, and authority
          certificates when FetchUselessDescriptors is set, regardless of
          whether tor is a directory cache or not. Fixes bug 20667; bugfix
          on all recent tor versions.
    
      o Minor bugfixes (documentation):
        - Update the tor manual page to document every option that can not
          be changed while tor is running. Fixes bug 21122.
    
      o Minor bugfixes (ed25519 certificates):
        - Correctly interpret ed25519 certificates that would expire some
          time after 19 Jan 2038. Fixes bug 20027; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (fallback directories):
        - Avoid checking fallback candidates' DirPorts if they are down in
          OnionOO. When a relay operator has multiple relays, this
          prioritizes relays that are up over relays that are down. Fixes
          bug 20926; bugfix on 0.2.8.3-alpha.
        - Stop failing when OUTPUT_COMMENTS is True in updateFallbackDirs.py.
          Fixes bug 20877; bugfix on 0.2.8.3-alpha.
        - Stop failing when a relay has no uptime data in
          updateFallbackDirs.py. Fixes bug 20945; bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (hidden service):
        - Clean up the code for expiring intro points with no associated
          circuits. It was causing, rarely, a service with some expiring
          introduction points to not open enough additional introduction
          points. Fixes part of bug 21302; bugfix on 0.2.7.2-alpha.
        - Resolve two possible underflows which could lead to creating and
          closing a lot of introduction point circuits in a non-stop loop.
          Fixes bug 21302; bugfix on 0.2.7.2-alpha.
        - Stop setting the torrc option HiddenServiceStatistics to "0" just
          because we're not a bridge or relay. Instead, we preserve whatever
          value the user set (or didn't set). Fixes bug 21150; bugfix
          on 0.2.6.2-alpha.
    
      o Minor bugfixes (hidden services):
        - Make hidden services check for failed intro point connections,
          even when they have exceeded their intro point creation limit.
          Fixes bug 21596; bugfix on 0.2.7.2-alpha. Reported by Alec Muffett.
        - Make hidden services with 8 to 10 introduction points check for
          failed circuits immediately after startup. Previously, they would
          wait for 5 minutes before performing their first checks. Fixes bug
          21594; bugfix on 0.2.3.9-alpha. Reported by Alec Muffett.
        - Stop ignoring misconfigured hidden services. Instead, refuse to
          start tor until the misconfigurations have been corrected. Fixes
          bug 20559; bugfix on multiple commits in 0.2.7.1-alpha
          and earlier.
    
      o Minor bugfixes (IPv6):
        - Make IPv6-using clients try harder to find an IPv6 directory
          server. Fixes bug 20999; bugfix on 0.2.8.2-alpha.
        - When IPv6 addresses have not been downloaded yet (microdesc
          consensus documents don't list relay IPv6 addresses), use hard-
          coded addresses for authorities, fallbacks, and configured
          bridges. Now IPv6-only clients can use microdescriptors. Fixes bug
          20996; bugfix on b167e82 from 19608 in 0.2.8.5-alpha.
    
      o Minor bugfixes (memory leak at exit):
        - Fix a small harmless memory leak at exit of the previously unused
          RSA->Ed identity cross-certificate. Fixes bug 17779; bugfix
          on 0.2.7.2-alpha.
    
      o Minor bugfixes (onion services):
        - Allow the number of introduction points to be as low as 0, rather
          than as low as 3. Fixes bug 21033; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (portability):
        - Use "OpenBSD" compiler macro instead of "OPENBSD" or "__OpenBSD__".
          It is supported by OpenBSD itself, and also by most OpenBSD
          variants (such as Bitrig). Fixes bug 20980; bugfix
          on 0.1.2.1-alpha.
    
      o Minor bugfixes (portability, also in 0.2.9.9):
        - Avoid crashing when Tor is built using headers that contain
          CLOCK_MONOTONIC_COARSE, but then tries to run on an older kernel
          without CLOCK_MONOTONIC_COARSE. Fixes bug 21035; bugfix
          on 0.2.9.1-alpha.
        - Fix Libevent detection on platforms without Libevent 1 headers
          installed. Fixes bug 21051; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (relay):
        - Avoid a double-marked-circuit warning that could happen when we
          receive DESTROY cells under heavy load. Fixes bug 20059; bugfix
          on 0.1.0.1-rc.
        - Honor DataDirectoryGroupReadable when tor is a relay. Previously,
          initializing the keys would reset the DataDirectory to 0700
          instead of 0750 even if DataDirectoryGroupReadable was set to 1.
          Fixes bug 19953; bugfix on 0.0.2pre16. Patch by "redfish".
    
      o Minor bugfixes (testing):
        - Fix Raspbian build issues related to missing socket errno in
          test_util.c. Fixes bug 21116; bugfix on 0.2.8.2. Patch by "hein".
        - Remove undefined behavior from the backtrace generator by removing
          its signal handler. Fixes bug 21026; bugfix on 0.2.5.2-alpha.
        - Use bash in src/test/test-network.sh. This ensures we reliably
          call chutney's newer tools/test-network.sh when available. Fixes
          bug 21562; bugfix on 0.2.9.1-alpha.
    
      o Minor bugfixes (tor-resolve):
        - The tor-resolve command line tool now rejects hostnames over 255
          characters in length. Previously, it would silently truncate them,
          which could lead to bugs. Fixes bug 21280; bugfix on 0.0.9pre5.
          Patch by "junglefowl".
    
      o Minor bugfixes (unit tests):
        - Allow the unit tests to pass even when DNS lookups of bogus
          addresses do not fail as expected. Fixes bug 20862 and 20863;
          bugfix on unit tests introduced in 0.2.8.1-alpha
          through 0.2.9.4-alpha.
    
      o Minor bugfixes (util):
        - When finishing writing a file to disk, if we were about to replace
          the file with the temporary file created before and we fail to
          replace it, remove the temporary file so it doesn't stay on disk.
          Fixes bug 20646; bugfix on 0.2.0.7-alpha. Patch by fk.
    
      o Minor bugfixes (Windows services):
        - Be sure to initialize the monotonic time subsystem before using
          it, even when running as an NT service. Fixes bug 21356; bugfix
          on 0.2.9.1-alpha.
    
      o Minor bugfixes (Windows):
        - Check for getpagesize before using it to mmap files. This fixes
          compilation in some MinGW environments. Fixes bug 20530; bugfix on
          0.1.2.1-alpha. Reported by "ice".
    
      o Code simplification and refactoring:
        - Abolish all global guard context in entrynodes.c; replace with new
          guard_selection_t structure as preparation for proposal 271.
          Closes ticket 19858.
        - Extract magic numbers in circuituse.c into defined variables.
        - Introduce rend_service_is_ephemeral() that tells if given onion
          service is ephemeral. Replace unclear NULL-checkings for service
          directory with this function. Closes ticket 20526.
        - Refactor circuit_is_available_for_use to remove unnecessary check.
        - Refactor circuit_predict_and_launch_new for readability and
          testability. Closes ticket 18873.
        - Refactor code to manipulate global_origin_circuit_list into
          separate functions. Closes ticket 20921.
        - Refactor large if statement in purpose_needs_anonymity to use
          switch statement instead. Closes part of ticket 20077.
        - Refactor the hashing API to return negative values for errors, as
          is done as throughout the codebase. Closes ticket 20717.
        - Remove data structures that were used to index or_connection
          objects by their RSA identity digests. These structures are fully
          redundant with the similar structures used in the
          channel abstraction.
        - Remove duplicate code in the channel_write_*cell() functions.
          Closes ticket 13827; patch from Pingl.
        - Remove redundant behavior of is_sensitive_dir_purpose, refactor to
          use only purpose_needs_anonymity. Closes part of ticket 20077.
        - The code to generate and parse EXTEND and EXTEND2 cells has been
          replaced with code automatically generated by the
          "trunnel" utility.
    
      o Documentation (formatting):
        - Clean up formatting of tor.1 man page and HTML doc, where <pre>
          blocks were incorrectly appearing. Closes ticket 20885.
    
      o Documentation (man page):
        - Clarify many options in tor.1 and add some min/max values for
          HiddenService options. Closes ticket 21058.
    
      o Documentation:
        - Change '1' to 'weight_scale' in consensus bw weights calculation
          comments, as that is reality. Closes ticket 20273. Patch
          from pastly.
        - Clarify that when ClientRejectInternalAddresses is enabled (which
          is the default), multicast DNS hostnames for machines on the local
          network (of the form *.local) are also rejected. Closes
          ticket 17070.
        - Correct the value for AuthDirGuardBWGuarantee in the manpage, from
          250 KBytes to 2 MBytes. Fixes bug 20435; bugfix on 0.2.5.6-alpha.
        - Include the "TBits" unit in Tor's man page. Fixes part of bug
          20622; bugfix on 0.2.5.1-alpha.
        - Small fixes to the fuzzing documentation. Closes ticket 21472.
        - Stop the man page from incorrectly stating that HiddenServiceDir
          must already exist. Fixes 20486.
        - Update the description of the directory server options in the
          manual page, to clarify that a relay no longer needs to set
          DirPort in order to be a directory cache. Closes ticket 21720.
    
      o Removed features:
        - The AuthDirMaxServersPerAuthAddr option no longer exists: The same
          limit for relays running on a single IP applies to authority IP
          addresses as well as to non-authority IP addresses. Closes
          ticket 20960.
        - The UseDirectoryGuards torrc option no longer exists: all users
          that use entry guards will also use directory guards. Related to
          proposal 271; implements part of ticket 20831.
    
      o Testing:
        - Add tests for networkstatus_compute_bw_weights_v10.
        - Add unit tests circuit_predict_and_launch_new.
        - Extract dummy_origin_circuit_new so it can be used by other
          test functions.
        - New unit tests for tor_htonll(). Closes ticket 19563. Patch
          from "overcaffeinated".
        - Perform the coding style checks when running the tests and fail
          when coding style violations are found. Closes ticket 5500.
    
    
    Changes in version 0.2.8.13 - 2017-03-03
      Tor 0.2.8.13 backports a security fix from later Tor
      releases.  Anybody running Tor 0.2.8.12 or earlier should upgrade to this
      this release, if for some reason they cannot upgrade to a later
      release series, and if they build Tor with the --enable-expensive-hardening
      option.
    
      Note that support for Tor 0.2.8.x is ending next year: we will not issue
      any fixes for the Tor 0.2.8.x series after 1 Jan 2018.  If you need
      a Tor release series with longer-term support, we recommend Tor 0.2.9.x.
    
      o Major bugfixes (parsing, backported from 0.3.0.4-rc):
        - Fix an integer underflow bug when comparing malformed Tor
          versions. This bug could crash Tor when built with
          --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
          0.2.9.8, which were built with -ftrapv by default. In other cases
          it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
          on 0.0.8pre1. Found by OSS-Fuzz.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.7.7 - 2017-03-03
      Tor 0.2.7.7 backports a number of security fixes from later Tor
      releases.  Anybody running Tor 0.2.7.6 or earlier should upgrade to
      this release, if for some reason they cannot upgrade to a later
      release series.
    
      Note that support for Tor 0.2.7.x is ending this year: we will not issue
      any fixes for the Tor 0.2.7.x series after 1 August 2017.  If you need
      a Tor release series with longer-term support, we recommend Tor 0.2.9.x.
    
      o Directory authority changes (backport from 0.2.8.5-rc):
        - Urras is no longer a directory authority. Closes ticket 19271.
    
      o Directory authority changes (backport from 0.2.9.2-alpha):
        - The "Tonga" bridge authority has been retired; the new bridge
          authority is "Bifroest". Closes tickets 19728 and 19690.
    
      o Directory authority key updates (backport from 0.2.8.1-alpha):
        - Update the V3 identity key for the dannenberg directory authority:
          it was changed on 18 November 2015. Closes task 17906. Patch
          by "teor".
    
      o Major bugfixes (parsing, security, backport from 0.2.9.8):
        - Fix a bug in parsing that could cause clients to read a single
          byte past the end of an allocated region. This bug could be used
          to cause hardened clients (built with --enable-expensive-hardening)
          to crash if they tried to visit a hostile hidden service. Non-
          hardened clients are only affected depending on the details of
          their platform's memory allocator. Fixes bug 21018; bugfix on
          0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
          2016-12-002 and as CVE-2016-1254.
    
      o Major bugfixes (security, client, DNS proxy, backport from 0.2.8.3-alpha):
        - Stop a crash that could occur when a client running with DNSPort
          received a query with multiple address types, and the first
          address type was not supported. Found and fixed by Scott Dial.
          Fixes bug 18710; bugfix on 0.2.5.4-alpha.
        - Prevent a class of security bugs caused by treating the contents
          of a buffer chunk as if they were a NUL-terminated string. At
          least one such bug seems to be present in all currently used
          versions of Tor, and would allow an attacker to remotely crash
          most Tor instances, especially those compiled with extra compiler
          hardening. With this defense in place, such bugs can't crash Tor,
          though we should still fix them as they occur. Closes ticket
          20384 (TROVE-2016-10-001).
    
      o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
        - Avoid a difficult-to-trigger heap corruption attack when extending
          a smartlist to contain over 16GB of pointers. Fixes bug 18162;
          bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
          Reported by Guido Vranken.
    
      o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
        - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
          bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".
    
      o Major bugfixes (key management, backport from 0.2.8.3-alpha):
        - If OpenSSL fails to generate an RSA key, do not retain a dangling
          pointer to the previous (uninitialized) key value. The impact here
          should be limited to a difficult-to-trigger crash, if OpenSSL is
          running an engine that makes key generation failures possible, or
          if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
          0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
          Baishakhi Ray.
    
      o Major bugfixes (parsing, backported from 0.3.0.4-rc):
        - Fix an integer underflow bug when comparing malformed Tor
          versions. This bug could crash Tor when built with
          --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
          0.2.9.8, which were built with -ftrapv by default. In other cases
          it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
          on 0.0.8pre1. Found by OSS-Fuzz.
    
      o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
        - Make memwipe() do nothing when passed a NULL pointer or buffer of
          zero size. Check size argument to memwipe() for underflow. Fixes
          bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
          patch by "teor".
    
      o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
        - Make Tor survive errors involving connections without a
          corresponding event object. Previously we'd fail with an
          assertion; now we produce a log message. Related to bug 16248.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.6.11 - 2017-03-03
      Tor 0.2.6.11 backports a number of security fixes from later Tor
      releases.  Anybody running Tor 0.2.6.10 or earlier should upgrade to
      this release, if for some reason they cannot upgrade to a later
      release series.
    
      Note that support for Tor 0.2.6.x is ending this year: we will not issue
      any fixes for the Tor 0.2.6.x series after 1 August 2017.  If you need
      a Tor release series with longer-term support, we recommend Tor 0.2.9.x.
    
      o Directory authority changes (backport from 0.2.8.5-rc):
        - Urras is no longer a directory authority. Closes ticket 19271.
    
      o Directory authority changes (backport from 0.2.9.2-alpha):
        - The "Tonga" bridge authority has been retired; the new bridge
          authority is "Bifroest". Closes tickets 19728 and 19690.
    
      o Directory authority key updates (backport from 0.2.8.1-alpha):
        - Update the V3 identity key for the dannenberg directory authority:
          it was changed on 18 November 2015. Closes task 17906. Patch
          by "teor".
    
      o Major features (security fixes, backport from 0.2.9.4-alpha):
        - Prevent a class of security bugs caused by treating the contents
          of a buffer chunk as if they were a NUL-terminated string. At
          least one such bug seems to be present in all currently used
          versions of Tor, and would allow an attacker to remotely crash
          most Tor instances, especially those compiled with extra compiler
          hardening. With this defense in place, such bugs can't crash Tor,
          though we should still fix them as they occur. Closes ticket
          20384 (TROVE-2016-10-001).
    
      o Major bugfixes (parsing, security, backport from 0.2.9.8):
        - Fix a bug in parsing that could cause clients to read a single
          byte past the end of an allocated region. This bug could be used
          to cause hardened clients (built with --enable-expensive-hardening)
          to crash if they tried to visit a hostile hidden service. Non-
          hardened clients are only affected depending on the details of
          their platform's memory allocator. Fixes bug 21018; bugfix on
          0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
          2016-12-002 and as CVE-2016-1254.
    
      o Major bugfixes (security, client, DNS proxy, backport from 0.2.8.3-alpha):
        - Stop a crash that could occur when a client running with DNSPort
          received a query with multiple address types, and the first
          address type was not supported. Found and fixed by Scott Dial.
          Fixes bug 18710; bugfix on 0.2.5.4-alpha.
    
      o Major bugfixes (security, correctness, backport from 0.2.7.4-rc):
        - Fix an error that could cause us to read 4 bytes before the
          beginning of an openssl string. This bug could be used to cause
          Tor to crash on systems with unusual malloc implementations, or
          systems with unusual hardening installed. Fixes bug 17404; bugfix
          on 0.2.3.6-alpha.
    
      o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
        - Avoid a difficult-to-trigger heap corruption attack when extending
          a smartlist to contain over 16GB of pointers. Fixes bug 18162;
          bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
          Reported by Guido Vranken.
    
      o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
        - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
          bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".
    
      o Major bugfixes (guard selection, backport from 0.2.7.6):
        - Actually look at the Guard flag when selecting a new directory
          guard. When we implemented the directory guard design, we
          accidentally started treating all relays as if they have the Guard
          flag during guard selection, leading to weaker anonymity and worse
          performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
          by Mohsen Imani.
    
      o Major bugfixes (key management, backport from 0.2.8.3-alpha):
        - If OpenSSL fails to generate an RSA key, do not retain a dangling
          pointer to the previous (uninitialized) key value. The impact here
          should be limited to a difficult-to-trigger crash, if OpenSSL is
          running an engine that makes key generation failures possible, or
          if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
          0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
          Baishakhi Ray.
    
      o Major bugfixes (parsing, backported from 0.3.0.4-rc):
        - Fix an integer underflow bug when comparing malformed Tor
          versions. This bug could crash Tor when built with
          --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
          0.2.9.8, which were built with -ftrapv by default. In other cases
          it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
          on 0.0.8pre1. Found by OSS-Fuzz.
    
      o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
        - Make memwipe() do nothing when passed a NULL pointer or buffer of
          zero size. Check size argument to memwipe() for underflow. Fixes
          bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
          patch by "teor".
    
      o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
        - Make Tor survive errors involving connections without a
          corresponding event object. Previously we'd fail with an
          assertion; now we produce a log message. Related to bug 16248.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (compilation, backport from 0.2.7.6):
        - Fix a compilation warning with Clang 3.6: Do not check the
          presence of an address which can never be NULL. Fixes bug 17781.
    
    
    Changes in version 0.2.5.13 - 2017-03-03
      Tor 0.2.5.13 backports a number of security fixes from later Tor
      releases.  Anybody running Tor 0.2.5.13 or earlier should upgrade to
      this release, if for some reason they cannot upgrade to a later
      release series.
    
      Note that support for Tor 0.2.5.x is ending next year: we will not issue
      any fixes for the Tor 0.2.5.x series after 1 May 2018.  If you need
      a Tor release series with longer-term support, we recommend Tor 0.2.9.x.
    
      o Directory authority changes (backport from 0.2.8.5-rc):
        - Urras is no longer a directory authority. Closes ticket 19271.
    
      o Directory authority changes (backport from 0.2.9.2-alpha):
        - The "Tonga" bridge authority has been retired; the new bridge
          authority is "Bifroest". Closes tickets 19728 and 19690.
    
      o Directory authority key updates (backport from 0.2.8.1-alpha):
        - Update the V3 identity key for the dannenberg directory authority:
          it was changed on 18 November 2015. Closes task 17906. Patch
          by "teor".
    
      o Major features (security fixes, backport from 0.2.9.4-alpha):
        - Prevent a class of security bugs caused by treating the contents
          of a buffer chunk as if they were a NUL-terminated string. At
          least one such bug seems to be present in all currently used
          versions of Tor, and would allow an attacker to remotely crash
          most Tor instances, especially those compiled with extra compiler
          hardening. With this defense in place, such bugs can't crash Tor,
          though we should still fix them as they occur. Closes ticket
          20384 (TROVE-2016-10-001).
    
      o Major bugfixes (parsing, security, backport from 0.2.9.8):
        - Fix a bug in parsing that could cause clients to read a single
          byte past the end of an allocated region. This bug could be used
          to cause hardened clients (built with --enable-expensive-hardening)
          to crash if they tried to visit a hostile hidden service. Non-
          hardened clients are only affected depending on the details of
          their platform's memory allocator. Fixes bug 21018; bugfix on
          0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
          2016-12-002 and as CVE-2016-1254.
    
      o Major bugfixes (security, client, DNS proxy, backport from 0.2.8.3-alpha):
        - Stop a crash that could occur when a client running with DNSPort
          received a query with multiple address types, and the first
          address type was not supported. Found and fixed by Scott Dial.
          Fixes bug 18710; bugfix on 0.2.5.4-alpha.
    
      o Major bugfixes (security, correctness, backport from 0.2.7.4-rc):
        - Fix an error that could cause us to read 4 bytes before the
          beginning of an openssl string. This bug could be used to cause
          Tor to crash on systems with unusual malloc implementations, or
          systems with unusual hardening installed. Fixes bug 17404; bugfix
          on 0.2.3.6-alpha.
    
      o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
        - Avoid a difficult-to-trigger heap corruption attack when extending
          a smartlist to contain over 16GB of pointers. Fixes bug 18162;
          bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
          Reported by Guido Vranken.
    
      o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
        - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
          bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".
    
      o Major bugfixes (guard selection, backport from 0.2.7.6):
        - Actually look at the Guard flag when selecting a new directory
          guard. When we implemented the directory guard design, we
          accidentally started treating all relays as if they have the Guard
          flag during guard selection, leading to weaker anonymity and worse
          performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
          by Mohsen Imani.
    
      o Major bugfixes (key management, backport from 0.2.8.3-alpha):
        - If OpenSSL fails to generate an RSA key, do not retain a dangling
          pointer to the previous (uninitialized) key value. The impact here
          should be limited to a difficult-to-trigger crash, if OpenSSL is
          running an engine that makes key generation failures possible, or
          if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
          0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
          Baishakhi Ray.
    
      o Major bugfixes (parsing, backported from 0.3.0.4-rc):
        - Fix an integer underflow bug when comparing malformed Tor
          versions. This bug could crash Tor when built with
          --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
          0.2.9.8, which were built with -ftrapv by default. In other cases
          it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
          on 0.0.8pre1. Found by OSS-Fuzz.
    
      o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
        - Make memwipe() do nothing when passed a NULL pointer or buffer of
          zero size. Check size argument to memwipe() for underflow. Fixes
          bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
          patch by "teor".
    
      o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
        - Make Tor survive errors involving connections without a
          corresponding event object. Previously we'd fail with an
          assertion; now we produce a log message. Related to bug 16248.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (compilation, backport from 0.2.7.6):
        - Fix a compilation warning with Clang 3.6: Do not check the
          presence of an address which can never be NULL. Fixes bug 17781.
    
      o Minor bugfixes (crypto error-handling, backport from 0.2.7.2-alpha):
        - Check for failures from crypto_early_init, and refuse to continue.
          A previous typo meant that we could keep going with an
          uninitialized crypto library, and would have OpenSSL initialize
          its own PRNG. Fixes bug 16360; bugfix on 0.2.5.2-alpha, introduced
          when implementing ticket 4900. Patch by "teor".
    
      o Minor bugfixes (hidden service, backport from 0.2.7.1-alpha):
        - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
          a client authorized hidden service. Fixes bug 15823; bugfix
          on 0.2.1.6-alpha.
    
    
    Changes in version 0.2.4.28 - 2017-03-03
      Tor 0.2.4.28 backports a number of security fixes from later Tor
      releases.  Anybody running Tor 0.2.4.27 or earlier should upgrade to
      this release, if for some reason they cannot upgrade to a later
      release series.
    
      Note that support for Tor 0.2.4.x is ending soon: we will not issue
      any fixes for the Tor 0.2.4.x series after 1 August 2017.  If you need
      a Tor release series with long-term support, we recommend Tor 0.2.9.x.
    
      o Directory authority changes (backport from 0.2.8.5-rc):
        - Urras is no longer a directory authority. Closes ticket 19271.
    
      o Directory authority changes (backport from 0.2.9.2-alpha):
        - The "Tonga" bridge authority has been retired; the new bridge
          authority is "Bifroest". Closes tickets 19728 and 19690.
    
      o Directory authority key updates (backport from 0.2.8.1-alpha):
        - Update the V3 identity key for the dannenberg directory authority:
          it was changed on 18 November 2015. Closes task 17906. Patch
          by "teor".
    
      o Major features (security fixes, backport from 0.2.9.4-alpha):
        - Prevent a class of security bugs caused by treating the contents
          of a buffer chunk as if they were a NUL-terminated string. At
          least one such bug seems to be present in all currently used
          versions of Tor, and would allow an attacker to remotely crash
          most Tor instances, especially those compiled with extra compiler
          hardening. With this defense in place, such bugs can't crash Tor,
          though we should still fix them as they occur. Closes ticket
          20384 (TROVE-2016-10-001).
    
      o Major bugfixes (parsing, security, backport from 0.2.9.8):
        - Fix a bug in parsing that could cause clients to read a single
          byte past the end of an allocated region. This bug could be used
          to cause hardened clients (built with --enable-expensive-hardening)
          to crash if they tried to visit a hostile hidden service. Non-
          hardened clients are only affected depending on the details of
          their platform's memory allocator. Fixes bug 21018; bugfix on
          0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
          2016-12-002 and as CVE-2016-1254.
    
      o Major bugfixes (security, correctness, backport from 0.2.7.4-rc):
        - Fix an error that could cause us to read 4 bytes before the
          beginning of an openssl string. This bug could be used to cause
          Tor to crash on systems with unusual malloc implementations, or
          systems with unusual hardening installed. Fixes bug 17404; bugfix
          on 0.2.3.6-alpha.
    
      o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
        - Avoid a difficult-to-trigger heap corruption attack when extending
          a smartlist to contain over 16GB of pointers. Fixes bug 18162;
          bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
          Reported by Guido Vranken.
    
      o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
        - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
          bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".
    
      o Major bugfixes (guard selection, backport from 0.2.7.6):
        - Actually look at the Guard flag when selecting a new directory
          guard. When we implemented the directory guard design, we
          accidentally started treating all relays as if they have the Guard
          flag during guard selection, leading to weaker anonymity and worse
          performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
          by Mohsen Imani.
    
      o Major bugfixes (key management, backport from 0.2.8.3-alpha):
        - If OpenSSL fails to generate an RSA key, do not retain a dangling
          pointer to the previous (uninitialized) key value. The impact here
          should be limited to a difficult-to-trigger crash, if OpenSSL is
          running an engine that makes key generation failures possible, or
          if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
          0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
          Baishakhi Ray.
    
      o Major bugfixes (parsing, backported from 0.3.0.4-rc):
        - Fix an integer underflow bug when comparing malformed Tor
          versions. This bug could crash Tor when built with
          --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
          0.2.9.8, which were built with -ftrapv by default. In other cases
          it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
          on 0.0.8pre1. Found by OSS-Fuzz.
    
      o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
        - Make memwipe() do nothing when passed a NULL pointer or buffer of
          zero size. Check size argument to memwipe() for underflow. Fixes
          bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
          patch by "teor".
    
      o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
        - Make Tor survive errors involving connections without a
          corresponding event object. Previously we'd fail with an
          assertion; now we produce a log message. Related to bug 16248.
    
      o Minor features (DoS-resistance, backport from 0.2.7.1-alpha):
        - Make it harder for attackers to overload hidden services with
          introductions, by blocking multiple introduction requests on the
          same circuit. Resolves ticket 15515.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (compilation, backport from 0.2.7.6):
        - Fix a compilation warning with Clang 3.6: Do not check the
          presence of an address which can never be NULL. Fixes bug 17781.
    
      o Minor bugfixes (hidden service, backport from 0.2.7.1-alpha):
        - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
          a client authorized hidden service. Fixes bug 15823; bugfix
          on 0.2.1.6-alpha.
    
    
    Changes in version 0.2.9.10 - 2017-03-01
      Tor 0.2.9.10 backports a security fix from later Tor release.  It also
      includes fixes for some major issues affecting directory authorities,
      LibreSSL compatibility, and IPv6 correctness.
    
      The Tor 0.2.9.x release series is now marked as a long-term-support
      series.  We intend to backport security fixes to 0.2.9.x until at
      least January of 2020.
    
      o Major bugfixes (directory authority, 0.3.0.3-alpha):
        - During voting, when marking a relay as a probable sybil, do not
          clear its BadExit flag: sybils can still be bad in other ways
          too. (We still clear the other flags.) Fixes bug 21108; bugfix
          on 0.2.0.13-alpha.
    
      o Major bugfixes (IPv6 Exits, backport from 0.3.0.3-alpha):
        - Stop rejecting all IPv6 traffic on Exits whose exit policy rejects
          any IPv6 addresses. Instead, only reject a port over IPv6 if the
          exit policy rejects that port on more than an IPv6 /16 of
          addresses. This bug was made worse by 17027 in 0.2.8.1-alpha,
          which rejected a relay's own IPv6 address by default. Fixes bug
          21357; bugfix on commit 004f3f4e53 in 0.2.4.7-alpha.
    
      o Major bugfixes (parsing, also in 0.3.0.4-rc):
        - Fix an integer underflow bug when comparing malformed Tor
          versions. This bug could crash Tor when built with
          --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
          0.2.9.8, which were built with -ftrapv by default. In other cases
          it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
          on 0.0.8pre1. Found by OSS-Fuzz.
    
      o Minor features (directory authorities, also in 0.3.0.4-rc):
        - Directory authorities now reject descriptors that claim to be
          malformed versions of Tor. Helps prevent exploitation of
          bug 21278.
        - Reject version numbers with components that exceed INT32_MAX.
          Otherwise 32-bit and 64-bit platforms would behave inconsistently.
          Fixes bug 21450; bugfix on 0.0.8pre1.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
          Country database.
    
      o Minor features (portability, compilation, backport from 0.3.0.3-alpha):
        - Autoconf now checks to determine if OpenSSL structures are opaque,
          instead of explicitly checking for OpenSSL version numbers. Part
          of ticket 21359.
        - Support building with recent LibreSSL code that uses opaque
          structures. Closes ticket 21359.
    
      o Minor bugfixes (code correctness, also in 0.3.0.4-rc):
        - Repair a couple of (unreachable or harmless) cases of the risky
          comparison-by-subtraction pattern that caused bug 21278.
    
      o Minor bugfixes (tor-resolve, backport from 0.3.0.3-alpha):
        - The tor-resolve command line tool now rejects hostnames over 255
          characters in length. Previously, it would silently truncate them,
          which could lead to bugs. Fixes bug 21280; bugfix on 0.0.9pre5.
          Patch by "junglefowl".
    
    
    Changes in version 0.2.9.9 - 2017-01-23
      Tor 0.2.9.9 fixes a denial-of-service bug where an attacker could
      cause relays and clients to crash, even if they were not built with
      the --enable-expensive-hardening option. This bug affects all 0.2.9.x
      versions, and also affects 0.3.0.1-alpha: all relays running an affected
      version should upgrade.
    
      This release also resolves a client-side onion service reachability
      bug, and resolves a pair of small portability issues.
    
      o Major bugfixes (security):
        - Downgrade the "-ftrapv" option from "always on" to "only on when
          --enable-expensive-hardening is provided." This hardening option,
          like others, can turn survivable bugs into crashes -- and having
          it on by default made a (relatively harmless) integer overflow bug
          into a denial-of-service bug. Fixes bug 21278 (TROVE-2017-001);
          bugfix on 0.2.9.1-alpha.
    
      o Major bugfixes (client, onion service):
        - Fix a client-side onion service reachability bug, where multiple
          socks requests to an onion service (or a single slow request)
          could cause us to mistakenly mark some of the service's
          introduction points as failed, and we cache that failure so
          eventually we run out and can't reach the service. Also resolves a
          mysterious "Remote server sent bogus reason code 65021" log
          warning. The bug was introduced in ticket 17218, where we tried to
          remember the circuit end reason as a uint16_t, which mangled
          negative values. Partially fixes bug 21056 and fixes bug 20307;
          bugfix on 0.2.8.1-alpha.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the January 4 2017 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (portability):
        - Avoid crashing when Tor is built using headers that contain
          CLOCK_MONOTONIC_COARSE, but then tries to run on an older kernel
          without CLOCK_MONOTONIC_COARSE. Fixes bug 21035; bugfix
          on 0.2.9.1-alpha.
        - Fix Libevent detection on platforms without Libevent 1 headers
          installed. Fixes bug 21051; bugfix on 0.2.9.1-alpha.
    
    
    Changes in version 0.2.8.12 - 2016-12-19
      Tor 0.2.8.12 backports a fix for a medium-severity issue (bug 21018
      below) where Tor clients could crash when attempting to visit a
      hostile hidden service. Clients are recommended to upgrade as packages
      become available for their systems.
    
      It also includes an updated list of fallback directories, backported
      from 0.2.9.
    
      Now that the Tor 0.2.9 series is stable, only major bugfixes will be
      backported to 0.2.8 in the future.
    
      o Major bugfixes (parsing, security, backported from 0.2.9.8):
        - Fix a bug in parsing that could cause clients to read a single
          byte past the end of an allocated region. This bug could be used
          to cause hardened clients (built with --enable-expensive-hardening)
          to crash if they tried to visit a hostile hidden service. Non-
          hardened clients are only affected depending on the details of
          their platform's memory allocator. Fixes bug 21018; bugfix on
          0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
          2016-12-002 and as CVE-2016-1254.
    
      o Minor features (fallback directory list, backported from 0.2.9.8):
        - Replace the 81 remaining fallbacks of the 100 originally
          introduced in Tor 0.2.8.3-alpha in March 2016, with a list of 177
          fallbacks (123 new, 54 existing, 27 removed) generated in December
          2016. Resolves ticket 20170.
    
      o Minor features (geoip, backported from 0.2.9.7-rc):
        - Update geoip and geoip6 to the December 7 2016 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.9.8 - 2016-12-19
      Tor 0.2.9.8 is the first stable release of the Tor 0.2.9 series.
    
      The Tor 0.2.9 series makes mandatory a number of security features
      that were formerly optional. It includes support for a new shared-
      randomness protocol that will form the basis for next generation
      hidden services, includes a single-hop hidden service mode for
      optimizing .onion services that don't actually want to be hidden,
      tries harder not to overload the directory authorities with excessive
      downloads, and supports a better protocol versioning scheme for
      improved compatibility with other implementations of the Tor protocol.
    
      And of course, there are numerous other bugfixes and improvements.
    
      This release also includes a fix for a medium-severity issue (bug
      21018 below) where Tor clients could crash when attempting to visit a
      hostile hidden service. Clients are recommended to upgrade as packages
      become available for their systems.
    
      Below are listed the changes since Tor 0.2.8.11.  For a list of
      changes since 0.2.9.7-rc, see the ChangeLog file.
    
      o New system requirements:
        - When building with OpenSSL, Tor now requires version 1.0.1 or
          later. OpenSSL 1.0.0 and earlier are no longer supported by the
          OpenSSL team, and should not be used. Closes ticket 20303.
        - Tor now requires Libevent version 2.0.10-stable or later. Older
          versions of Libevent have less efficient backends for several
          platforms, and lack the DNS code that we use for our server-side
          DNS support. This implements ticket 19554.
        - Tor now requires zlib version 1.2 or later, for security,
          efficiency, and (eventually) gzip support. (Back when we started,
          zlib 1.1 and zlib 1.0 were still found in the wild. 1.2 was
          released in 2003. We recommend the latest version.)
    
      o Deprecated features:
        - A number of DNS-cache-related sub-options for client ports are now
          deprecated for security reasons, and may be removed in a future
          version of Tor. (We believe that client-side DNS caching is a bad
          idea for anonymity, and you should not turn it on.) The options
          are: CacheDNS, CacheIPv4DNS, CacheIPv6DNS, UseDNSCache,
          UseIPv4Cache, and UseIPv6Cache.
        - A number of options are deprecated for security reasons, and may
          be removed in a future version of Tor. The options are:
          AllowDotExit, AllowInvalidNodes, AllowSingleHopCircuits,
          AllowSingleHopExits, ClientDNSRejectInternalAddresses,
          CloseHSClientCircuitsImmediatelyOnTimeout,
          CloseHSServiceRendCircuitsImmediatelyOnTimeout,
          ExcludeSingleHopRelays, FastFirstHopPK, TLSECGroup,
          UseNTorHandshake, and WarnUnsafeSocks.
        - The *ListenAddress options are now deprecated as unnecessary: the
          corresponding *Port options should be used instead. These options
          may someday be removed. The affected options are:
          ControlListenAddress, DNSListenAddress, DirListenAddress,
          NATDListenAddress, ORListenAddress, SocksListenAddress,
          and TransListenAddress.
    
      o Major bugfixes (parsing, security, new since 0.2.9.7-rc):
        - Fix a bug in parsing that could cause clients to read a single
          byte past the end of an allocated region. This bug could be used
          to cause hardened clients (built with --enable-expensive-hardening)
          to crash if they tried to visit a hostile hidden service. Non-
          hardened clients are only affected depending on the details of
          their platform's memory allocator. Fixes bug 21018; bugfix on
          0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
          2016-12-002 and as CVE-2016-1254.
    
      o Major features (build, hardening):
        - Tor now builds with -ftrapv by default on compilers that support
          it. This option detects signed integer overflow (which C forbids),
          and turns it into a hard-failure. We do not apply this option to
          code that needs to run in constant time to avoid side-channels;
          instead, we use -fwrapv in that code. Closes ticket 17983.
        - When --enable-expensive-hardening is selected, stop applying the
          clang/gcc sanitizers to code that needs to run in constant time.
          Although we are aware of no introduced side-channels, we are not
          able to prove that there are none. Related to ticket 17983.
    
      o Major features (circuit building, security):
        - Authorities, relays, and clients now require ntor keys in all
          descriptors, for all hops (except for rare hidden service protocol
          cases), for all circuits, and for all other roles. Part of
          ticket 19163.
        - Authorities, relays, and clients only use ntor, except for
          rare cases in the hidden service protocol. Part of ticket 19163.
    
      o Major features (compilation):
        - Our big list of extra GCC warnings is now enabled by default when
          building with GCC (or with anything like Clang that claims to be
          GCC-compatible). To make all warnings into fatal compilation
          errors, pass --enable-fatal-warnings to configure. Closes
          ticket 19044.
        - Use the Autoconf macro AC_USE_SYSTEM_EXTENSIONS to automatically
          turn on C and POSIX extensions. (Previously, we attempted to do
          this on an ad hoc basis.) Closes ticket 19139.
    
      o Major features (directory authorities, hidden services):
        - Directory authorities can now perform the shared randomness
          protocol specified by proposal 250. Using this protocol, directory
          authorities generate a global fresh random value every day. In the
          future, this value will be used by hidden services to select
          HSDirs. This release implements the directory authority feature;
          the hidden service side will be implemented in the future as part
          of proposal 224. Resolves ticket 16943; implements proposal 250.
    
      o Major features (downloading, random exponential backoff):
        - When we fail to download an object from a directory service, wait
          for an (exponentially increasing) randomized amount of time before
          retrying, rather than a fixed interval as we did before. This
          prevents a group of Tor instances from becoming too synchronized,
          or a single Tor instance from becoming too predictable, in its
          download schedule. Closes ticket 15942.
    
      o Major features (resource management):
        - Tor can now notice it is about to run out of sockets, and
          preemptively close connections of lower priority. (This feature is
          off by default for now, since the current prioritizing method is
          yet not mature enough. You can enable it by setting
          "DisableOOSCheck 0", but watch out: it might close some sockets
          you would rather have it keep.) Closes ticket 18640.
    
      o Major features (single-hop "hidden" services):
        - Add experimental HiddenServiceSingleHopMode and
          HiddenServiceNonAnonymousMode options. When both are set to 1,
          every hidden service on that Tor instance becomes a non-anonymous
          Single Onion Service. Single Onions make one-hop (direct)
          connections to their introduction and rendezvous points. One-hop
          circuits make Single Onion servers easily locatable, but clients
          remain location-anonymous. This is compatible with the existing
          hidden service implementation, and works on the current Tor
          network without any changes to older relays or clients. Implements
          proposal 260, completes ticket 17178. Patch by teor and asn.
    
      o Major features (subprotocol versions):
        - Tor directory authorities now vote on a set of recommended
          "subprotocol versions", and on a set of required subprotocol
          versions. Clients and relays that lack support for a _required_
          subprotocol version will not start; those that lack support for a
          _recommended_ subprotocol version will warn the user to upgrade.
          This change allows compatible implementations of the Tor protocol(s)
          to exist without pretending to be 100% bug-compatible with
          particular releases of Tor itself. Closes ticket 19958; implements
          part of proposal 264.
    
      o Major bugfixes (circuit building):
        - Hidden service client-to-intro-point and service-to-rendezvous-
          point circuits use the TAP key supplied by the protocol, to avoid
          epistemic attacks. Fixes bug 19163; bugfix on 0.2.4.18-rc.
    
      o Major bugfixes (download scheduling):
        - Avoid resetting download status for consensuses hourly, since we
          already have another, smarter retry mechanism. Fixes bug 8625;
          bugfix on 0.2.0.9-alpha.
        - If a consensus expires while we are waiting for certificates to
          download, stop waiting for certificates.
        - If we stop waiting for certificates less than a minute after we
          started downloading them, do not consider the certificate download
          failure a separate failure. Fixes bug 20533; bugfix
          on 0.2.0.9-alpha.
        - When using exponential backoff in test networks, use a lower
          exponent, so the delays do not vary as much. This helps test
          networks bootstrap consistently. Fixes bug 20597; bugfix on 20499.
    
      o Major bugfixes (exit policies):
        - Avoid disclosing exit outbound bind addresses, configured port
          bind addresses, and local interface addresses in relay descriptors
          by default under ExitPolicyRejectPrivate. Instead, only reject
          these (otherwise unlisted) addresses if
          ExitPolicyRejectLocalInterfaces is set. Fixes bug 18456; bugfix on
          0.2.7.2-alpha. Patch by teor.
    
      o Major bugfixes (hidden services):
        - Allow Tor clients with appropriate controllers to work with
          FetchHidServDescriptors set to 0. Previously, this option also
          disabled descriptor cache lookup, thus breaking hidden services
          entirely. Fixes bug 18704; bugfix on 0.2.0.20-rc. Patch by "twim".
        - Clients now require hidden services to include the TAP keys for
          their intro points in the hidden service descriptor. This prevents
          an inadvertent upgrade to ntor, which a malicious hidden service
          could use to distinguish clients by consensus version. Fixes bug
          20012; bugfix on 0.2.4.8-alpha. Patch by teor.
    
      o Major bugfixes (relay, resolver, logging):
        - For relays that don't know their own address, avoid attempting a
          local hostname resolve for each descriptor we download. This
          will cut down on the number of "Success: chose address 'x.x.x.x'"
          log lines, and also avoid confusing clock jumps if the resolver
          is slow. Fixes bugs 20423 and 20610; bugfix on 0.2.8.1-alpha.
    
      o Minor features (port flags):
        - Add new flags to the *Port options to give finer control over which
          requests are allowed. The flags are NoDNSRequest, NoOnionTraffic,
          and the synthetic flag OnionTrafficOnly, which is equivalent to
          NoDNSRequest, NoIPv4Traffic, and NoIPv6Traffic. Closes enhancement
          18693; patch by "teor".
    
      o Minor features (build, hardening):
        - Detect and work around a libclang_rt problem that would prevent
          clang from finding __mulodi4() on some 32-bit platforms, and thus
          keep -ftrapv from linking on those systems. Closes ticket 19079.
        - When building on a system without runtime support for the runtime
          hardening options, try to log a useful warning at configuration
          time, rather than an incomprehensible warning at link time. If
          expensive hardening was requested, this warning becomes an error.
          Closes ticket 18895.
    
      o Minor features (client, directory):
        - Since authorities now omit all routers that lack the Running and
          Valid flags, we assume that any relay listed in the consensus must
          have those flags. Closes ticket 20001; implements part of
          proposal 272.
    
      o Minor features (code safety):
        - In our integer-parsing functions, ensure that the maximum value we
          allow is no smaller than the minimum value. Closes ticket 19063;
          patch from "U+039b".
    
      o Minor features (compilation, portability):
        - Compile correctly on MacOS 10.12 (aka "Sierra"). Closes
          ticket 20241.
    
      o Minor features (config):
        - Warn users when descriptor and port addresses are inconsistent.
          Mitigates bug 13953; patch by teor.
    
      o Minor features (controller):
        - Allow controllers to configure basic client authorization on
          hidden services when they create them with the ADD_ONION controller
          command. Implements ticket 15588. Patch by "special".
        - Fire a STATUS_SERVER controller event whenever the hibernation
          status changes between "awake"/"soft"/"hard". Closes ticket 18685.
        - Implement new GETINFO queries for all downloads that use
          download_status_t to schedule retries. This allows controllers to
          examine the schedule for pending downloads. Closes ticket 19323.
    
      o Minor features (development tools, etags):
        - Teach the "make tags" Makefile target how to correctly find
          "MOCK_IMPL" function definitions. Patch from nherring; closes
          ticket 16869.
    
      o Minor features (directory authority):
        - After voting, if the authorities decide that a relay is not
          "Valid", they no longer include it in the consensus at all. Closes
          ticket 20002; implements part of proposal 272.
        - Directory authorities now only give the Guard flag to a relay if
          they are also giving it the Stable flag. This change allows us to
          simplify path selection for clients. It should have minimal effect
          in practice, since >99% of Guards already have the Stable flag.
          Implements ticket 18624.
        - Directory authorities now write their v3-status-votes file out to
          disk earlier in the consensus process, so we have a record of the
          votes even if we abort the consensus process. Resolves
          ticket 19036.
    
      o Minor features (fallback directory list, new since 0.2.9.7-rc):
        - Replace the 81 remaining fallbacks of the 100 originally
          introduced in Tor 0.2.8.3-alpha in March 2016, with a list of 177
          fallbacks (123 new, 54 existing, 27 removed) generated in December
          2016. Resolves ticket 20170.
    
      o Minor features (hidden service):
        - Stop being so strict about the payload length of "rendezvous1"
          cells. We used to be locked in to the "TAP" handshake length, and
          now we can handle better handshakes like "ntor". Resolves
          ticket 18998.
    
      o Minor features (infrastructure, time):
        - Tor now includes an improved timer backend, so that we can
          efficiently support tens or hundreds of thousands of concurrent
          timers, as will be needed for some of our planned anti-traffic-
          analysis work. This code is based on William Ahern's "timeout.c"
          project, which implements a "tickless hierarchical timing wheel".
          Closes ticket 18365.
        - Tor now uses the operating system's monotonic timers (where
          available) for internal fine-grained timing. Previously we would
          look at the system clock, and then attempt to compensate for the
          clock running backwards. Closes ticket 18908.
    
      o Minor features (logging):
        - Add a set of macros to check nonfatal assertions, for internal
          use. Migrating more of our checks to these should help us avoid
          needless crash bugs. Closes ticket 18613.
        - Provide a more useful warning message when configured with an
          invalid Nickname. Closes ticket 18300; patch from "icanhasaccount".
        - When dumping unparseable router descriptors, optionally store them
          in separate files, named by digest, up to a configurable size
          limit. You can change the size limit by setting the
          MaxUnparseableDescSizeToLog option, and disable this feature by
          setting that option to 0. Closes ticket 18322.
    
      o Minor features (performance):
        - Change the "optimistic data" extension from "off by default" to
          "on by default". The default was ordinarily overridden by a
          consensus option, but when clients were bootstrapping for the
          first time, they would not have a consensus to get the option
          from. Changing this default saves a round-trip during startup.
          Closes ticket 18815.
    
      o Minor features (relay, usability):
        - When the directory authorities refuse a bad relay's descriptor,
          encourage the relay operator to contact us. Many relay operators
          won't notice this line in their logs, but it's a win if even a few
          learn why we don't like what their relay was doing. Resolves
          ticket 18760.
    
      o Minor features (security, TLS):
        - Servers no longer support clients that lack AES ciphersuites.
          (3DES is no longer considered an acceptable cipher.) We believe
          that no such Tor clients currently exist, since Tor has required
          OpenSSL 0.9.7 or later since 2009. Closes ticket 19998.
    
      o Minor features (testing):
        - Disable memory protections on OpenBSD when performing our unit
          tests for memwipe(). The test deliberately invokes undefined
          behavior, and the OpenBSD protections interfere with this. Patch
          from "rubiate". Closes ticket 20066.
        - Move the test-network.sh script to chutney, and modify tor's test-
          network.sh to call the (newer) chutney version when available.
          Resolves ticket 19116. Patch by teor.
        - Use the lcov convention for marking lines as unreachable, so that
          we don't count them when we're generating test coverage data.
          Update our coverage tools to understand this convention. Closes
          ticket 16792.
        - Our link-handshake unit tests now check that when invalid
          handshakes fail, they fail with the error messages we expected.
        - Our unit testing code that captures log messages no longer
          prevents them from being written out if the user asked for them
          (by passing --debug or --info or --notice or --warn to the "test"
          binary). This change prevents us from missing unexpected log
          messages simply because we were looking for others. Related to
          ticket 19999.
        - The unit tests now log all warning messages with the "BUG" flag.
          Previously, they only logged errors by default. This change will
          help us make our testing code more correct, and make sure that we
          only hit this code when we mean to. In the meantime, however,
          there will be more warnings in the unit test logs than before.
          This is preparatory work for ticket 19999.
        - The unit tests now treat any failure of a "tor_assert_nonfatal()"
          assertion as a test failure.
        - We've done significant work to make the unit tests run faster.
    
      o Minor features (testing, ipv6):
        - Add the hs-ipv6 chutney target to make test-network-all's IPv6
          tests. Remove bridges+hs, as it's somewhat redundant. This
          requires a recent chutney version that supports IPv6 clients,
          relays, and authorities. Closes ticket 20069; patch by teor.
        - Add the single-onion and single-onion-ipv6 chutney targets to
          "make test-network-all". This requires a recent chutney version
          with the single onion network flavors (git c72a652 or later).
          Closes ticket 20072; patch by teor.
    
      o Minor features (Tor2web):
        - Make Tor2web clients respect ReachableAddresses. This feature was
          inadvertently enabled in 0.2.8.6, then removed by bugfix 19973 on
          0.2.8.7. Implements feature 20034. Patch by teor.
    
      o Minor features (unix domain sockets):
        - When configuring a unix domain socket for a SocksPort,
          ControlPort, or Hidden service, you can now wrap the address in
          quotes, using C-style escapes inside the quotes. This allows unix
          domain socket paths to contain spaces. Resolves ticket 18753.
    
      o Minor features (user interface):
        - Tor now supports the ability to declare options deprecated, so
          that we can recommend that people stop using them. Previously, this
          was done in an ad-hoc way. There is a new --list-deprecated-options
          command-line option to list all of the deprecated options. Closes
          ticket 19820.
    
      o Minor features (virtual addresses):
        - Increase the maximum number of bits for the IPv6 virtual network
          prefix from 16 to 104. In this way, the condition for address
          allocation is less restrictive. Closes ticket 20151; feature
          on 0.2.4.7-alpha.
    
      o Minor bug fixes (circuits):
        - Use the CircuitBuildTimeout option whenever
          LearnCircuitBuildTimeout is disabled. Previously, we would respect
          the option when a user disabled it, but not when it was disabled
          because some other option was set. Fixes bug 20073; bugfix on
          0.2.4.12-alpha. Patch by teor.
    
      o Minor bugfixes (build):
        - The current Git revision when building from a local repository is
          now detected correctly when using git worktrees. Fixes bug 20492;
          bugfix on 0.2.3.9-alpha.
    
      o Minor bugfixes (relay address discovery):
        - Stop reordering IP addresses returned by the OS. This makes it
          more likely that Tor will guess the same relay IP address every
          time. Fixes issue 20163; bugfix on 0.2.7.1-alpha, ticket 17027.
          Reported by René Mayrhofer, patch by "cypherpunks".
    
      o Minor bugfixes (memory allocation):
        - Change how we allocate memory for large chunks on buffers, to
          avoid a (currently impossible) integer overflow, and to waste less
          space when allocating unusually large chunks. Fixes bug 20081;
          bugfix on 0.2.0.16-alpha. Issue identified by Guido Vranken.
    
      o Minor bugfixes (bootstrap):
        - Remember the directory server we fetched the consensus or previous
          certificates from, and use it to fetch future authority
          certificates. This change improves bootstrapping performance.
          Fixes bug 18963; bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (circuits):
        - Make sure extend_info_from_router() is only called on servers.
          Fixes bug 19639; bugfix on 0.2.8.1-alpha.
    
      o Minor bugfixes (client, fascistfirewall):
        - Avoid spurious warnings when ReachableAddresses or FascistFirewall
          is set. Fixes bug 20306; bugfix on 0.2.8.2-alpha.
    
      o Minor bugfixes (client, unix domain sockets):
        - Disable IsolateClientAddr when using AF_UNIX backed SocksPorts as
          the client address is meaningless. Fixes bug 20261; bugfix
          on 0.2.6.3-alpha.
    
      o Minor bugfixes (code style):
        - Fix an integer signedness conversion issue in the case conversion
          tables. Fixes bug 19168; bugfix on 0.2.1.11-alpha.
    
      o Minor bugfixes (compilation):
        - Build correctly on versions of libevent2 without support for
          evutil_secure_rng_add_bytes(). Fixes bug 19904; bugfix
          on 0.2.5.4-alpha.
        - When building with Clang, use a full set of GCC warnings.
          (Previously, we included only a subset, because of the way we
          detected them.) Fixes bug 19216; bugfix on 0.2.0.1-alpha.
        - Detect Libevent2 functions correctly on systems that provide
          libevent2, but where libevent1 is linked with -levent. Fixes bug
          19904; bugfix on 0.2.2.24-alpha. Patch from Rubiate.
        - Run correctly when built on Windows build environments that
          require _vcsprintf(). Fixes bug 20560; bugfix on 0.2.2.11-alpha.
    
      o Minor bugfixes (configuration):
        - When parsing quoted configuration values from the torrc file,
          handle Windows line endings correctly. Fixes bug 19167; bugfix on
          0.2.0.16-alpha. Patch from "Pingl".
    
      o Minor bugfixes (directory authority):
        - Authorities now sort the "package" lines in their votes, for ease
          of debugging. (They are already sorted in consensus documents.)
          Fixes bug 18840; bugfix on 0.2.6.3-alpha.
        - Die with a more useful error when the operator forgets to place
          the authority_signing_key file into the keys directory. This
          avoids an uninformative assert & traceback about having an invalid
          key. Fixes bug 20065; bugfix on 0.2.0.1-alpha.
        - When allowing private addresses, mark Exits that only exit to
          private locations as such. Fixes bug 20064; bugfix
          on 0.2.2.9-alpha.
        - When parsing a detached signature, make sure we use the length of
          the digest algorithm instead of a hardcoded DIGEST256_LEN in
          order to avoid comparing bytes out-of-bounds with a smaller digest
          length such as SHA1. Fixes bug 19066; bugfix on 0.2.2.6-alpha.
    
      o Minor bugfixes (getpass):
        - Defensively fix a non-triggerable heap corruption at do_getpass()
          to protect ourselves from mistakes in the future. Fixes bug
          19223; bugfix on 0.2.7.3-rc. Bug found by Guido Vranken, patch
          by nherring.
    
      o Minor bugfixes (guard selection):
        - Don't mark guards as unreachable if connection_connect() fails.
          That function fails for local reasons, so it shouldn't reveal
          anything about the status of the guard. Fixes bug 14334; bugfix
          on 0.2.3.10-alpha.
        - Use a single entry guard even if the NumEntryGuards consensus
          parameter is not provided. Fixes bug 17688; bugfix
          on 0.2.5.6-alpha.
    
      o Minor bugfixes (hidden services):
        - Increase the minimum number of internal circuits we preemptively
          build from 2 to 3, so a circuit is available when a client
          connects to another onion service. Fixes bug 13239; bugfix
          on 0.1.0.1-rc.
        - Allow hidden services to run on IPv6 addresses even when the
          IPv6Exit option is not set. Fixes bug 18357; bugfix
          on 0.2.4.7-alpha.
        - Stop logging intro point details to the client log on certain
          error conditions. Fixed as part of bug 20012; bugfix on
          0.2.4.8-alpha. Patch by teor.
        - When deleting an ephemeral hidden service, close its intro points
          even if they are not completely open. Fixes bug 18604; bugfix
          on 0.2.7.1-alpha.
        - When configuring hidden services, check every hidden service
          directory's permissions. Previously, we only checked the last
          hidden service. Fixes bug 20529; bugfix on 0.2.6.2-alpha.
    
      o Minor bugfixes (IPv6, testing):
        - Check for IPv6 correctly on Linux when running test networks.
          Fixes bug 19905; bugfix on 0.2.7.3-rc; patch by teor.
    
      o Minor bugfixes (Linux seccomp2 sandbox):
        - Add permission to run the sched_yield() and sigaltstack() system
          calls, in order to support versions of Tor compiled with asan or
          ubsan code that use these calls. Now "sandbox 1" and
          "--enable-expensive-hardening" should be compatible on more
          systems. Fixes bug 20063; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (logging):
        - Downgrade a harmless log message about the
          pending_entry_connections list from "warn" to "info". Mitigates
          bug 19926.
        - Log a more accurate message when we fail to dump a microdescriptor.
          Fixes bug 17758; bugfix on 0.2.2.8-alpha. Patch from Daniel Pinto.
        - When logging a directory ownership mismatch, log the owning
          username correctly. Fixes bug 19578; bugfix on 0.2.2.29-beta.
        - When we are unable to remove the bw_accounting file, do not warn
          if the reason we couldn't remove it was that it didn't exist.
          Fixes bug 19964; bugfix on 0.2.5.4-alpha. Patch from pastly.
    
      o Minor bugfixes (memory leak):
        - Fix a series of slow memory leaks related to parsing torrc files
          and options. Fixes bug 19466; bugfix on 0.2.1.6-alpha.
        - Avoid a small memory leak when informing worker threads about
          rotated onion keys. Fixes bug 20401; bugfix on 0.2.6.3-alpha.
        - Fix a small memory leak when receiving AF_UNIX connections on a
          SocksPort. Fixes bug 20716; bugfix on 0.2.6.3-alpha.
        - When moving a signed descriptor object from a source to an
          existing destination, free the allocated memory inside that
          destination object. Fixes bug 20715; bugfix on 0.2.8.3-alpha.
        - Fix a memory leak and use-after-free error when removing entries
          from the sandbox's getaddrinfo() cache. Fixes bug 20710; bugfix on
          0.2.5.5-alpha. Patch from "cypherpunks".
        - Fix a small, uncommon memory leak that could occur when reading a
          truncated ed25519 key file. Fixes bug 18956; bugfix
          on 0.2.6.1-alpha.
    
      o Minor bugfixes (option parsing):
        - Count unix sockets when counting client listeners (SOCKS, Trans,
          NATD, and DNS). This has no user-visible behavior changes: these
          options are set once, and never read. Required for correct
          behavior in ticket 17178. Fixes bug 19677; bugfix on
          0.2.6.3-alpha. Patch by teor.
    
      o Minor bugfixes (options):
        - Check the consistency of UseEntryGuards and EntryNodes more
          reliably. Fixes bug 20074; bugfix on 0.2.4.12-alpha. Patch
          by teor.
        - Stop changing the configured value of UseEntryGuards on
          authorities and Tor2web clients. Fixes bug 20074; bugfix on
          commits 51fc6799 in 0.1.1.16-rc and acda1735 in 0.2.4.3-alpha.
          Patch by teor.
    
      o Minor bugfixes (relay):
        - Ensure relays don't make multiple connections during bootstrap.
          Fixes bug 20591; bugfix on 0.2.8.1-alpha.
        - Do not try to parallelize workers more than 16x without the user
          explicitly configuring us to do so, even if we do detect more than
          16 CPU cores. Fixes bug 19968; bugfix on 0.2.3.1-alpha.
    
      o Minor bugfixes (testing):
        - The test-stem and test-network makefile targets now depend only on
          the tor binary that they are testing. Previously, they depended on
          "make all". Fixes bug 18240; bugfix on 0.2.8.2-alpha. Based on a
          patch from "cypherpunks".
        - Allow clients to retry HSDirs much faster in test networks. Fixes
          bug 19702; bugfix on 0.2.7.1-alpha. Patch by teor.
        - Avoid a unit test failure on systems with over 16 detectable CPU
          cores. Fixes bug 19968; bugfix on 0.2.3.1-alpha.
        - Let backtrace tests work correctly under AddressSanitizer:
          disable ASAN's detection of segmentation faults while running
          test_bt.sh, so that we can make sure that our own backtrace
          generation code works. Fixes bug 18934; bugfix
          on 0.2.5.2-alpha. Patch from "cypherpunks".
        - Fix the test-network-all target on out-of-tree builds by using the
          correct path to the test driver script. Fixes bug 19421; bugfix
          on 0.2.7.3-rc.
        - Stop spurious failures in the local interface address discovery
          unit tests. Fixes bug 20634; bugfix on 0.2.8.1-alpha; patch by
          Neel Chauhan.
        - Use ECDHE ciphers instead of ECDH in tortls tests. LibreSSL has
          removed the ECDH ciphers which caused the tests to fail on
          platforms which use it. Fixes bug 20460; bugfix on 0.2.8.1-alpha.
        - The tor_tls_server_info_callback unit test no longer crashes when
          debug-level logging is turned on. Fixes bug 20041; bugfix
          on 0.2.8.1-alpha.
    
      o Minor bugfixes (time):
        - Improve overflow checks in tv_udiff and tv_mdiff. Fixes bug 19483;
          bugfix on all released tor versions.
        - When computing the difference between two times in milliseconds,
          we now round to the nearest millisecond correctly. Previously, we
          could sometimes round in the wrong direction. Fixes bug 19428;
          bugfix on 0.2.2.2-alpha.
    
      o Minor bugfixes (Tor2web):
        - Prevent Tor2web clients from running hidden services: these services
          are not anonymous due to the one-hop client paths. Fixes bug
          19678. Patch by teor.
    
      o Minor bugfixes (user interface):
        - Display a more accurate number of suppressed messages in the log
          rate-limiter. Previously, there was a potential integer overflow
          in the counter. Now, if the number of messages hits a maximum, the
          rate-limiter doesn't count any further. Fixes bug 19435; bugfix
          on 0.2.4.11-alpha.
        - Fix a typo in the passphrase prompt for the ed25519 identity key.
          Fixes bug 19503; bugfix on 0.2.7.2-alpha.
    
      o Code simplification and refactoring:
        - Remove redundant declarations of the MIN macro. Closes
          ticket 18889.
        - Rename tor_dup_addr() to tor_addr_to_str_dup() to avoid confusion.
          Closes ticket 18462; patch from "icanhasaccount".
        - Split the 600-line directory_handle_command_get function into
          separate functions for different URL types. Closes ticket 16698.
    
      o Documentation:
        - Add module-level internal documentation for 36 C files that
          previously didn't have a high-level overview. Closes ticket 20385.
        - Correct the IPv6 syntax in our documentation for the
          VirtualAddrNetworkIPv6 torrc option. Closes ticket 19743.
        - Correct the minimum bandwidth value in torrc.sample, and queue a
          corresponding change for torrc.minimal. Closes ticket 20085.
        - Fix spelling of "--enable-tor2web-mode" in the manpage. Closes
          ticket 19153. Patch from "U+039b".
        - Module-level documentation for several more modules. Closes
          tickets 19287 and 19290.
        - Document the --passphrase-fd option in the tor manpage. Fixes bug
          19504; bugfix on 0.2.7.3-rc.
        - Document the default PathsNeededToBuildCircuits value that's used
          by clients when the directory authorities don't set
          min_paths_for_circs_pct. Fixes bug 20117; bugfix on 0.2.4.10-alpha.
          Patch by teor, reported by Jesse V.
        - Fix manual for the User option: it takes a username, not a UID.
          Fixes bug 19122; bugfix on 0.0.2pre16 (the first version to have
          a manpage!).
        - Fix the description of the --passphrase-fd option in the
          tor-gencert manpage. The option is used to pass the number of a
          file descriptor to read the passphrase from, not to read the file
          descriptor from. Fixes bug 19505; bugfix on 0.2.0.20-alpha.
    
      o Removed code:
        - We no longer include the (dead, deprecated) bufferevent code in
          Tor. Closes ticket 19450. Based on a patch from "U+039b".
    
      o Removed features:
        - Remove support for "GET /tor/bytes.txt" DirPort request, and
          "GETINFO dir-usage" controller request, which were only available
          via a compile-time option in Tor anyway. Feature was added in
          0.2.2.1-alpha. Resolves ticket 19035.
        - There is no longer a compile-time option to disable support for
          TransPort. (If you don't want TransPort, just don't use it.) Patch
          from "U+039b". Closes ticket 19449.
    
      o Testing:
        - Run more workqueue tests as part of "make check". These had
          previously been implemented, but you needed to know special
          command-line options to enable them.
        - We now have unit tests for our code to reject zlib "compression
          bombs". (Fortunately, the code works fine.)
    
    
    Changes in version 0.2.8.11 - 2016-12-08
      Tor 0.2.8.11 backports fixes for additional portability issues that
      could prevent Tor from building correctly on OSX Sierra, or with
      OpenSSL 1.1. Affected users should upgrade; others can safely stay
      with 0.2.8.10.
    
      o Minor bugfixes (portability):
        - Avoid compilation errors when building on OSX Sierra. Sierra began
          to support the getentropy() and clock_gettime() APIs, but created
          a few problems in doing so. Tor 0.2.9 has a more thorough set of
          workarounds; in 0.2.8, we are just using the /dev/urandom and mach
          monotonic time interfaces. Fixes bug 20865. Bugfix
          on 0.2.8.1-alpha.
    
      o Minor bugfixes (portability, backport from 0.2.9.5-alpha):
        - Fix compilation with OpenSSL 1.1 and less commonly-used CPU
          architectures. Closes ticket 20588.
    
    
    Changes in version 0.2.8.10 - 2016-12-02
      Tor 0.2.8.10 backports a fix for a bug that would sometimes make clients
      unusable after they left standby mode. It also backports fixes for
      a few portability issues and a small but problematic memory leak.
    
      o Major bugfixes (client reliability, backport from 0.2.9.5-alpha):
        - When Tor leaves standby because of a new application request, open
          circuits as needed to serve that request. Previously, we would
          potentially wait a very long time. Fixes part of bug 19969; bugfix
          on 0.2.8.1-alpha.
    
      o Major bugfixes (client performance, backport from 0.2.9.5-alpha):
        - Clients now respond to new application stream requests immediately
          when they arrive, rather than waiting up to one second before
          starting to handle them. Fixes part of bug 19969; bugfix
          on 0.2.8.1-alpha.
    
      o Minor bugfixes (portability, backport from 0.2.9.6-rc):
        - Work around a bug in the OSX 10.12 SDK that would prevent us from
          successfully targeting earlier versions of OSX. Resolves
          ticket 20235.
    
      o Minor bugfixes (portability, backport from 0.2.9.5-alpha):
        - Fix implicit conversion warnings under OpenSSL 1.1. Fixes bug
          20551; bugfix on 0.2.1.1-alpha.
    
      o Minor bugfixes (relay, backport from 0.2.9.5-alpha):
        - Work around a memory leak in OpenSSL 1.1 when encoding public
          keys. Fixes bug 20553; bugfix on 0.0.2pre8.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the November 3 2016 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.8.9 - 2016-10-17
      Tor 0.2.8.9 backports a fix for a security hole in previous versions
      of Tor that would allow a remote attacker to crash a Tor client,
      hidden service, relay, or authority. All Tor users should upgrade to
      this version, or to 0.2.9.4-alpha. Patches will be released for older
      versions of Tor.
    
      o Major features (security fixes, also in 0.2.9.4-alpha):
        - Prevent a class of security bugs caused by treating the contents
          of a buffer chunk as if they were a NUL-terminated string. At
          least one such bug seems to be present in all currently used
          versions of Tor, and would allow an attacker to remotely crash
          most Tor instances, especially those compiled with extra compiler
          hardening. With this defense in place, such bugs can't crash Tor,
          though we should still fix them as they occur. Closes ticket
          20384 (TROVE-2016-10-001).
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the October 4 2016 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.8.8 - 2016-09-23
      Tor 0.2.8.8 fixes two crash bugs present in previous versions of the
      0.2.8.x series. Relays running 0.2.8.x should upgrade, as should users
      who select public relays as their bridges.
    
      o Major bugfixes (crash):
        - Fix a complicated crash bug that could affect Tor clients
          configured to use bridges when replacing a networkstatus consensus
          in which one of their bridges was mentioned. OpenBSD users saw
          more crashes here, but all platforms were potentially affected.
          Fixes bug 20103; bugfix on 0.2.8.2-alpha.
    
      o Major bugfixes (relay, OOM handler):
        - Fix a timing-dependent assertion failure that could occur when we
          tried to flush from a circuit after having freed its cells because
          of an out-of-memory condition. Fixes bug 20203; bugfix on
          0.2.8.1-alpha. Thanks to "cypherpunks" for help diagnosing
          this one.
    
      o Minor feature (fallback directories):
        - Remove broken fallbacks from the hard-coded fallback directory
          list. Closes ticket 20190; patch by teor.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the September 6 2016 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.8.7 - 2016-08-24
      Tor 0.2.8.7 fixes an important bug related to the ReachableAddresses
      option in 0.2.8.6, and replaces a retiring bridge authority. Everyone
      who sets the ReachableAddresses option, and all bridges, are strongly
      encouraged to upgrade.
    
      o Directory authority changes:
        - The "Tonga" bridge authority has been retired; the new bridge
          authority is "Bifroest". Closes tickets 19728 and 19690.
    
      o Major bugfixes (client, security):
        - Only use the ReachableAddresses option to restrict the first hop
          in a path. In earlier versions of 0.2.8.x, it would apply to
          every hop in the path, with a possible degradation in anonymity
          for anyone using an uncommon ReachableAddress setting. Fixes bug
          19973; bugfix on 0.2.8.2-alpha.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the August 2 2016 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (compilation):
        - Remove an inappropriate "inline" in tortls.c that was causing
          warnings on older versions of GCC. Fixes bug 19903; bugfix
          on 0.2.8.1-alpha.
    
      o Minor bugfixes (fallback directories):
        - Avoid logging a NULL string pointer when loading fallback
          directory information. Fixes bug 19947; bugfix on 0.2.4.7-alpha
          and 0.2.8.1-alpha. Report and patch by "rubiate".
    
    
    Changes in version 0.2.8.6 - 2016-08-02
    
      Tor 0.2.8.6 is the first stable version of the Tor 0.2.8 series.
    
      The Tor 0.2.8 series improves client bootstrapping performance,
      completes the authority-side implementation of improved identity
      keys for relays, and includes numerous bugfixes and performance
      improvements throughout the program. This release continues to
      improve the coverage of Tor's test suite.  For a full list of
      changes since Tor 0.2.7, see the ReleaseNotes file.
    
      Below is a list of the changes since Tor 0.2.7.
    
      o New system requirements:
        - Tor no longer attempts to support platforms where the "time_t"
          type is unsigned. (To the best of our knowledge, only OpenVMS does
          this, and Tor has never actually built on OpenVMS.) Closes
          ticket 18184.
        - Tor no longer supports versions of OpenSSL with a broken
          implementation of counter mode. (This bug was present in OpenSSL
          1.0.0, and was fixed in OpenSSL 1.0.0a.) Tor still detects, but no
          longer runs with, these versions.
        - Tor now uses Autoconf version 2.63 or later, and Automake 1.11 or
          later (released in 2008 and 2009 respectively). If you are
          building Tor from the git repository instead of from the source
          distribution, and your tools are older than this, you will need to
          upgrade. Closes ticket 17732.
    
      o Directory authority changes:
        - Update the V3 identity key for the dannenberg directory authority:
          it was changed on 18 November 2015. Closes task 17906. Patch
          by teor.
        - Urras is no longer a directory authority. Closes ticket 19271.
    
      o Major features (directory system):
        - Include a trial list of default fallback directories, based on an
          opt-in survey of suitable relays. Doing this should make clients
          bootstrap more quickly and reliably, and reduce the load on the
          directory authorities. Closes ticket 15775. Patch by teor.
          Candidates identified using an OnionOO script by weasel, teor,
          gsathya, and karsten.
        - Previously only relays that explicitly opened a directory port
          (DirPort) accepted directory requests from clients. Now all
          relays, with and without a DirPort, accept and serve tunneled
          directory requests that they receive through their ORPort. You can
          disable this behavior using the new DirCache option. Closes
          ticket 12538.
        - When bootstrapping multiple consensus downloads at a time, use the
          first one that starts downloading, and close the rest. This
          reduces failures when authorities or fallback directories are slow
          or down. Together with the code for feature 15775, this feature
          should reduces failures due to fallback churn. Implements ticket
          4483. Patch by teor. Implements IPv4 portions of proposal 210 by
          mikeperry and teor.
    
      o Major features (security, Linux):
        - When Tor starts as root on Linux and is told to switch user ID, it
          can now retain the capability to bind to low ports. By default,
          Tor will do this only when it's switching user ID and some low
          ports have been configured. You can change this behavior with the
          new option KeepBindCapabilities. Closes ticket 8195.
    
      o Major bugfixes (client, bootstrapping):
        - Check if bootstrap consensus downloads are still needed when the
          linked connection attaches. This prevents tor making unnecessary
          begindir-style connections, which are the only directory
          connections tor clients make since the fix for 18483 was merged.
        - Fix some edge cases where consensus download connections may not
          have been closed, even though they were not needed. Related to fix
          for 18809.
        - Make relays retry consensus downloads the correct number of times,
          rather than the more aggressive client retry count. Fixes part of
          ticket 18809.
    
      o Major bugfixes (dns proxy mode, crash):
        - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
          bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".
    
      o Major bugfixes (ed25519, voting):
        - Actually enable support for authorities to match routers by their
          Ed25519 identities. Previously, the code had been written, but
          some debugging code that had accidentally been left in the
          codebase made it stay turned off. Fixes bug 17702; bugfix
          on 0.2.7.2-alpha.
        - When collating votes by Ed25519 identities, authorities now
          include a "NoEdConsensus" flag if the ed25519 value (or lack
          thereof) for a server does not reflect the majority consensus.
          Related to bug 17668; bugfix on 0.2.7.2-alpha.
        - When generating a vote with keypinning disabled, never include two
          entries for the same ed25519 identity. This bug was causing
          authorities to generate votes that they could not parse when a
          router violated key pinning by changing its RSA identity but
          keeping its Ed25519 identity. Fixes bug 17668; fixes part of bug
          18318. Bugfix on 0.2.7.2-alpha.
    
      o Major bugfixes (key management):
        - If OpenSSL fails to generate an RSA key, do not retain a dangling
          pointer to the previous (uninitialized) key value. The impact here
          should be limited to a difficult-to-trigger crash, if OpenSSL is
          running an engine that makes key generation failures possible, or
          if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
          0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
          Baishakhi Ray.
    
      o Major bugfixes (security, client, DNS proxy):
        - Stop a crash that could occur when a client running with DNSPort
          received a query with multiple address types, and the first
          address type was not supported. Found and fixed by Scott Dial.
          Fixes bug 18710; bugfix on 0.2.5.4-alpha.
    
      o Major bugfixes (security, compilation):
        - Correctly detect compiler flags on systems where _FORTIFY_SOURCE
          is predefined. Previously, our use of -D_FORTIFY_SOURCE would
          cause a compiler warning, thereby making other checks fail, and
          needlessly disabling compiler-hardening support. Fixes one case of
          bug 18841; bugfix on 0.2.3.17-beta. Patch from "trudokal".
        - Repair hardened builds under the clang compiler. Previously, our
          use of _FORTIFY_SOURCE would conflict with clang's address
          sanitizer. Fixes bug 14821; bugfix on 0.2.5.4-alpha.
    
      o Major bugfixes (security, pointers):
        - Avoid a difficult-to-trigger heap corruption attack when extending
          a smartlist to contain over 16GB of pointers. Fixes bug 18162;
          bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
          Reported by Guido Vranken.
    
      o Major bugfixes (testing):
        - Fix a bug that would block 'make test-network-all' on systems where
          IPv6 packets were lost. Fixes bug 19008; bugfix on 0.2.7.3-rc.
    
      o Major bugfixes (user interface):
        - Correctly give a warning in the cases where a relay is specified
          by nickname, and one such relay is found, but it is not officially
          Named. Fixes bug 19203; bugfix on 0.2.3.1-alpha.
    
      o Minor features (accounting):
        - Added two modes to the AccountingRule option: One for limiting
          only the number of bytes sent ("AccountingRule out"), and one for
          limiting only the number of bytes received ("AccountingRule in").
          Closes ticket 15989; patch from "unixninja92".
    
      o Minor features (bug-resistance):
        - Make Tor survive errors involving connections without a
          corresponding event object. Previously we'd fail with an
          assertion; now we produce a log message. Related to bug 16248.
        - Use tor_snprintf() and tor_vsnprintf() even in external and low-
          level code, to harden against accidental failures to NUL-
          terminate. Part of ticket 17852. Patch from jsturgix. Found
          with Flawfinder.
    
      o Minor features (build):
        - Detect systems with FreeBSD-derived kernels (such as GNU/kFreeBSD)
          as having possible IPFW support. Closes ticket 18448. Patch from
          Steven Chamberlain.
        - Since our build process now uses "make distcheck", we no longer
          force "make dist" to depend on "make check". Closes ticket 17893;
          patch from "cypherpunks".
        - Tor now builds once again with the recent OpenSSL 1.1 development
          branch (tested against 1.1.0-pre5 and 1.1.0-pre6-dev). We have been
          tracking OpenSSL 1.1 development as it has progressed, and fixing
          numerous compatibility issues as they arose. See tickets
          17549, 17921, 17984, 19499, and 18286.
        - When building manual pages, set the timezone to "UTC", so that the
          output is reproducible. Fixes bug 19558; bugfix on 0.2.2.9-alpha.
          Patch from intrigeri.
    
      o Minor features (clients):
        - Make clients, onion services, and bridge relays always use an
          encrypted begindir connection for directory requests. Resolves
          ticket 18483. Patch by teor.
    
      o Minor features (controller):
        - Add 'GETINFO exit-policy/reject-private/[default,relay]', so
          controllers can examine the the reject rules added by
          ExitPolicyRejectPrivate. This makes it easier for stem to display
          exit policies.
        - Adds the FallbackDir entries to 'GETINFO config/defaults'. Closes
          tickets 16774 and 17817. Patch by George Tankersley.
        - New 'GETINFO hs/service/desc/id/' command to retrieve a hidden
          service descriptor from a service's local hidden service
          descriptor cache. Closes ticket 14846.
    
      o Minor features (crypto):
        - Add SHA3 and SHAKE support to crypto.c. Closes ticket 17783.
        - Add SHA512 support to crypto.c. Closes ticket 17663; patch from
          George Tankersley.
        - Improve performance when hashing non-multiple of 8 sized buffers,
          based on Andrew Moon's public domain SipHash-2-4 implementation.
          Fixes bug 17544; bugfix on 0.2.5.3-alpha.
        - Validate the hard-coded Diffie-Hellman parameters and ensure that
          p is a safe prime, and g is a suitable generator. Closes
          ticket 18221.
        - When allocating a digest state object, allocate no more space than
          we actually need. Previously, we would allocate as much space as
          the state for the largest algorithm would need. This change saves
          up to 672 bytes per circuit. Closes ticket 17796.
    
      o Minor features (directory downloads):
        - Add UseDefaultFallbackDirs, which enables any hard-coded fallback
          directory mirrors. The default is 1; set it to 0 to disable
          fallbacks. Implements ticket 17576. Patch by teor.
        - Wait for busy authorities and fallback directories to become non-
          busy when bootstrapping. (A similar change was made in 6c443e987d
          for directory caches chosen from the consensus.) Closes ticket
          17864; patch by teor.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the July 6 2016 Maxmind GeoLite2
          Country database.
    
      o Minor features (hidden service directory):
        - Streamline relay-side hsdir handling: when relays consider whether
          to accept an uploaded hidden service descriptor, they no longer
          check whether they are one of the relays in the network that is
          "supposed" to handle that descriptor. Implements ticket 18332.
    
      o Minor features (IPv6):
        - Add ClientPreferIPv6DirPort, which is set to 0 by default. If set
          to 1, tor prefers IPv6 directory addresses.
        - Add ClientUseIPv4, which is set to 1 by default. If set to 0, tor
          avoids using IPv4 for client OR and directory connections.
        - Add address policy assume_action support for IPv6 addresses.
        - Add an argument 'ipv6=address:orport' to the DirAuthority and
          FallbackDir torrc options, to specify an IPv6 address for an
          authority or fallback directory. Add hard-coded ipv6 addresses for
          directory authorities that have them. Closes ticket 17327; patch
          from Nick Mathewson and teor.
        - Allow users to configure directory authorities and fallback
          directory servers with IPv6 addresses and ORPorts. Resolves
          ticket 6027.
        - Limit IPv6 mask bits to 128.
        - Make tor_ersatz_socketpair work on IPv6-only systems. Fixes bug
          17638; bugfix on 0.0.2pre8. Patch by teor.
        - Try harder to obey the IP version restrictions "ClientUseIPv4 0",
          "ClientUseIPv6 0", "ClientPreferIPv6ORPort", and
          "ClientPreferIPv6DirPort". Closes ticket 17840; patch by teor.
        - Warn when comparing against an AF_UNSPEC address in a policy, it's
          almost always a bug. Closes ticket 17863; patch by teor.
        - routerset_parse now accepts IPv6 literal addresses. Fixes bug
          17060; bugfix on 0.2.1.3-alpha. Patch by teor.
    
      o Minor features (Linux seccomp2 sandbox):
        - Reject attempts to change our Address with "Sandbox 1" enabled.
          Changing Address with Sandbox turned on would never actually work,
          but previously it would fail in strange and confusing ways. Found
          while fixing 18548.
    
      o Minor features (logging):
        - When logging to syslog, allow a tag to be added to the syslog
          identity (the string prepended to every log message). The tag can
          be configured with SyslogIdentityTag and defaults to none. Setting
          it to "foo" will cause logs to be tagged as "Tor-foo". Closes
          ticket 17194.
    
      o Minor features (portability):
        - Use timingsafe_memcmp() where available. Closes ticket 17944;
          patch from <logan@hackers.mu>.
    
      o Minor features (relay, address discovery):
        - Add a family argument to get_interface_addresses_raw() and
          subfunctions to make network interface address interogation more
          efficient. Now Tor can specifically ask for IPv4, IPv6 or both
          types of interfaces from the operating system. Resolves
          ticket 17950.
        - When get_interface_address6_list(.,AF_UNSPEC,.) is called and
          fails to enumerate interface addresses using the platform-specific
          API, have it rely on the UDP socket fallback technique to try and
          find out what IP addresses (both IPv4 and IPv6) our machine has.
          Resolves ticket 17951.
    
      o Minor features (replay cache):
        - The replay cache now uses SHA256 instead of SHA1. Implements
          feature 8961. Patch by teor, issue reported by rransom.
    
      o Minor features (robustness):
        - Exit immediately with an error message if the code attempts to use
          Libevent without having initialized it. This should resolve some
          frequently-made mistakes in our unit tests. Closes ticket 18241.
    
      o Minor features (security, clock):
        - Warn when the system clock appears to move back in time (when the
          state file was last written in the future). Tor doesn't know that
          consensuses have expired if the clock is in the past. Patch by
          teor. Implements ticket 17188.
    
      o Minor features (security, exit policies):
        - ExitPolicyRejectPrivate now rejects more private addresses by
          default. Specifically, it now rejects the relay's outbound bind
          addresses (if configured), and the relay's configured port
          addresses (such as ORPort and DirPort). Fixes bug 17027; bugfix on
          0.2.0.11-alpha. Patch by teor.
    
      o Minor features (security, memory erasure):
        - Make memwipe() do nothing when passed a NULL pointer or buffer of
          zero size. Check size argument to memwipe() for underflow. Fixes
          bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
          patch by teor.
        - Set the unused entries in a smartlist to NULL. This helped catch
          a (harmless) bug, and shouldn't affect performance too much.
          Implements ticket 17026.
        - Use SecureMemoryWipe() function to securely clean memory on
          Windows. Previously we'd use OpenSSL's OPENSSL_cleanse() function.
          Implements feature 17986.
        - Use explicit_bzero or memset_s when present. Previously, we'd use
          OpenSSL's OPENSSL_cleanse() function. Closes ticket 7419; patches
          from <logan@hackers.mu> and <selven@hackers.mu>.
    
      o Minor features (security, RNG):
        - Adjust Tor's use of OpenSSL's RNG APIs so that they absolutely,
          positively are not allowed to fail. Previously we depended on
          internal details of OpenSSL's behavior. Closes ticket 17686.
        - Never use the system entropy output directly for anything besides
          seeding the PRNG. When we want to generate important keys, instead
          of using system entropy directly, we now hash it with the PRNG
          stream. This may help resist certain attacks based on broken OS
          entropy implementations. Closes part of ticket 17694.
        - Use modern system calls (like getentropy() or getrandom()) to
          generate strong entropy on platforms that have them. Closes
          ticket 13696.
    
      o Minor features (security, win32):
        - Set SO_EXCLUSIVEADDRUSE on Win32 to avoid a local port-stealing
          attack. Fixes bug 18123; bugfix on all tor versions. Patch
          by teor.
    
      o Minor features (unix domain sockets):
        - Add a new per-socket option, RelaxDirModeCheck, to allow creating
          Unix domain sockets without checking the permissions on the parent
          directory. (Tor checks permissions by default because some
          operating systems only check permissions on the parent directory.
          However, some operating systems do look at permissions on the
          socket, and tor's default check is unneeded.) Closes ticket 18458.
          Patch by weasel.
    
      o Minor features (unix file permissions):
        - Defer creation of Unix sockets until after setuid. This avoids
          needing CAP_CHOWN and CAP_FOWNER when using systemd's
          CapabilityBoundingSet, or chown and fowner when using SELinux.
          Implements part of ticket 17562. Patch from Jamie Nguyen.
        - If any directory created by Tor is marked as group readable, the
          filesystem group is allowed to be either the default GID or the
          root user. Allowing root to read the DataDirectory prevents the
          need for CAP_READ_SEARCH when using systemd's
          CapabilityBoundingSet, or dac_read_search when using SELinux.
          Implements part of ticket 17562. Patch from Jamie Nguyen.
        - Introduce a new DataDirectoryGroupReadable option. If it is set to
          1, the DataDirectory will be made readable by the default GID.
          Implements part of ticket 17562. Patch from Jamie Nguyen.
    
      o Minor bugfixes (accounting):
        - The max bandwidth when using 'AccountRule sum' is now correctly
          logged. Fixes bug 18024; bugfix on 0.2.6.1-alpha. Patch
          from "unixninja92".
    
      o Minor bugfixes (assert, portability):
        - Fix an assertion failure in memarea.c on systems where "long" is
          shorter than the size of a pointer. Fixes bug 18716; bugfix
          on 0.2.1.1-alpha.
    
      o Minor bugfixes (bootstrap):
        - Consistently use the consensus download schedule for authority
          certificates. Fixes bug 18816; bugfix on 0.2.4.13-alpha.
    
      o Minor bugfixes (build):
        - Avoid spurious failures from configure files related to calling
          exit(0) in TOR_SEARCH_LIBRARY. Fixes bug 18626; bugfix on
          0.2.0.1-alpha. Patch from "cypherpunks".
        - Do not link the unit tests against both the testing and non-
          testing versions of the static libraries. Fixes bug 18490; bugfix
          on 0.2.7.1-alpha.
        - Resolve warnings when building on systems that are concerned with
          signed char. Fixes bug 18728; bugfix on 0.2.7.2-alpha
          and 0.2.6.1-alpha.
        - Silence spurious clang-scan warnings in the ed25519_donna code by
          explicitly initializing some objects. Fixes bug 18384; bugfix on
          0.2.7.2-alpha. Patch by teor.
        - When libscrypt.h is found, but no libscrypt library can be linked,
          treat libscrypt as absent. Fixes bug 19161; bugfix
          on 0.2.6.1-alpha.
        - Cause the unit tests to compile correctly on mingw64 versions that
          lack sscanf. Fixes bug 19213; bugfix on 0.2.7.1-alpha.
        - Don't try to use the pthread_condattr_setclock() function unless
          it actually exists. Fixes compilation on NetBSD-6.x. Fixes bug
          17819; bugfix on 0.2.6.3-alpha.
        - Fix backtrace compilation on FreeBSD. Fixes bug 17827; bugfix
          on 0.2.5.2-alpha.
        - Fix search for libevent libraries on OpenBSD (and other systems
          that install libevent 1 and libevent 2 in parallel). Fixes bug
          16651; bugfix on 0.1.0.7-rc. Patch from "rubiate".
        - Isolate environment variables meant for tests from the rest of the
          build system. Fixes bug 17818; bugfix on 0.2.7.3-rc.
        - Mark all object files that include micro-revision.i as depending
          on it, so as to make parallel builds more reliable. Fixes bug
          17826; bugfix on 0.2.5.1-alpha.
        - Remove config.log only from make distclean, not from make clean.
          Fixes bug 17924; bugfix on 0.2.4.1-alpha.
        - Replace usage of 'INLINE' with 'inline'. Fixes bug 17804; bugfix
          on 0.0.2pre8.
        - Remove an #endif from configure.ac so that we correctly detect the
          presence of in6_addr.s6_addr32. Fixes bug 17923; bugfix
          on 0.2.0.13-alpha.
    
      o Minor bugfixes (client, bootstrap):
        - Count receipt of new microdescriptors as progress towards
          bootstrapping. Previously, with EntryNodes set, Tor might not
          successfully repopulate the guard set on bootstrapping. Fixes bug
          16825; bugfix on 0.2.3.1-alpha.
    
      o Minor bugfixes (code correctness):
        - Fix a bad memory handling bug that would occur if we had queued a
          cell on a channel's incoming queue. Fortunately, we can't actually
          queue a cell like that as our code is constructed today, but it's
          best to avoid this kind of error, even if there isn't any code
          that triggers it today. Fixes bug 18570; bugfix on 0.2.4.4-alpha.
        - Assert that allocated memory held by the reputation code is freed
          according to its internal counters. Fixes bug 17753; bugfix
          on 0.1.1.1-alpha.
        - Assert when the TLS contexts fail to initialize. Fixes bug 17683;
          bugfix on 0.0.6.
        - Update to the latest version of Trunnel, which tries harder to
          avoid generating code that can invoke memcpy(p,NULL,0). Bug found
          by clang address sanitizer. Fixes bug 18373; bugfix
          on 0.2.7.2-alpha.
        - When closing an entry connection, generate a warning if we should
          have sent an end cell for it but we haven't. Fixes bug 17876;
          bugfix on 0.2.3.2-alpha.
    
      o Minor bugfixes (configuration):
        - Fix a tiny memory leak when parsing a port configuration ending in
          ":auto". Fixes bug 18374; bugfix on 0.2.3.3-alpha.
    
      o Minor bugfixes (containers):
        - If we somehow attempt to construct a heap with more than
          1073741822 elements, avoid an integer overflow when maintaining
          the heap property. Fixes bug 18296; bugfix on 0.1.2.1-alpha.
    
      o Minor bugfixes (controller, microdescriptors):
        - Make GETINFO dir/status-vote/current/consensus conform to the
          control specification by returning "551 Could not open cached
          consensus..." when not caching consensuses. Fixes bug 18920;
          bugfix on 0.2.2.6-alpha.
    
      o Minor bugfixes (crypto):
        - Check the return value of HMAC() and assert on failure. Fixes bug
          17658; bugfix on 0.2.3.6-alpha. Patch by teor.
    
      o Minor bugfixes (directories):
        - When fetching extrainfo documents, compare their SHA256 digests
          and Ed25519 signing key certificates with the routerinfo that led
          us to fetch them, rather than with the most recent routerinfo.
          Otherwise we generate many spurious warnings about mismatches.
          Fixes bug 17150; bugfix on 0.2.7.2-alpha.
        - When generating a URL for a directory server on an IPv6 address,
          wrap the IPv6 address in square brackets. Fixes bug 18051; bugfix
          on 0.2.3.9-alpha. Patch from Malek.
    
      o Minor bugfixes (downloading):
        - Predict more correctly whether we'll be downloading over HTTP when
          we determine the maximum length of a URL. This should avoid a
          "BUG" warning about the Squid HTTP proxy and its URL limits. Fixes
          bug 19191.
    
      o Minor bugfixes (exit policies, security):
        - Refresh an exit relay's exit policy when interface addresses
          change. Previously, tor only refreshed the exit policy when the
          configured external address changed. Fixes bug 18208; bugfix on
          0.2.7.3-rc. Patch by teor.
    
      o Minor bugfixes (fallback directories):
        - Mark fallbacks as "too busy" when they return a 503 response,
          rather than just marking authorities. Fixes bug 17572; bugfix on
          0.2.4.7-alpha. Patch by teor.
        - When requesting extrainfo descriptors from a trusted directory
          server, check whether it is an authority or a fallback directory
          which supports extrainfo descriptors. Fixes bug 18489; bugfix on
          0.2.4.7-alpha. Reported by atagar, patch by teor.
    
      o Minor bugfixes (hidden service, client):
        - Handle the case where the user makes several fast consecutive
          requests to the same .onion address. Previously, the first six
          requests would each trigger a descriptor fetch, each picking a
          directory (there are 6 overall) and the seventh one would fail
          because no directories were left, thereby triggering a close on
          all current directory connections asking for the hidden service.
          The solution here is to not close the connections if we have
          pending directory fetches. Fixes bug 15937; bugfix
          on 0.2.7.1-alpha.
    
      o Minor bugfixes (hidden service, control port):
        - Add the onion address to the HS_DESC event for the UPLOADED action
          both on success or failure. It was previously hardcoded with
          UNKNOWN. Fixes bug 16023; bugfix on 0.2.7.2-alpha.
    
      o Minor bugfixes (hidden service, directory):
        - Bridges now refuse "rendezvous2" (hidden service descriptor)
          publish attempts. Suggested by ticket 18332.
    
      o Minor bugfixes (IPv6):
        - Update the limits in max_dl_per_request for IPv6 address length.
          Fixes bug 17573; bugfix on 0.2.1.5-alpha.
    
      o Minor bugfixes (Linux seccomp2 sandbox):
        - Allow more syscalls when running with "Sandbox 1" enabled:
          sysinfo, getsockopt(SO_SNDBUF), and setsockopt(SO_SNDBUFFORCE). On
          some systems, these are required for Tor to start. Fixes bug
          18397; bugfix on 0.2.5.1-alpha. Patch from Daniel Pinto.
        - Allow IPPROTO_UDP datagram sockets when running with "Sandbox 1",
          so that get_interface_address6_via_udp_socket_hack() can work.
          Fixes bug 19660; bugfix on 0.2.5.1-alpha.
        - Allow the setrlimit syscall, and the prlimit and prlimit64
          syscalls, which some libc implementations use under the hood.
          Fixes bug 15221; bugfix on 0.2.5.1-alpha.
        - Avoid a 10-second delay when starting as a client with "Sandbox 1"
          enabled and no DNS resolvers configured. This should help TAILS
          start up faster. Fixes bug 18548; bugfix on 0.2.5.1-alpha.
        - Fix a crash when using offline master ed25519 keys with the Linux
          seccomp2 sandbox enabled. Fixes bug 17675; bugfix on 0.2.7.3-rc.
        - Allow statistics to be written to disk when "Sandbox 1" is
          enabled. Fixes bugs 19556 and 19957; bugfix on 0.2.5.1-alpha and
          0.2.6.1-alpha respectively.
    
      o Minor bugfixes (logging):
        - In log messages that include a function name, use __FUNCTION__
          instead of __PRETTY_FUNCTION__. In GCC, these are synonymous, but
          with clang __PRETTY_FUNCTION__ has extra information we don't
          need. Fixes bug 16563; bugfix on 0.0.2pre8. Fix by Tom van
          der Woerdt.
        - Remove needless quotes from a log message about unparseable
          addresses. Fixes bug 17843; bugfix on 0.2.3.3-alpha.
        - Scrub service name in "unrecognized service ID" log messages.
          Fixes bug 18600; bugfix on 0.2.4.11-alpha.
        - When logging information about an unparsable networkstatus vote or
          consensus, do not say "vote" when we mean consensus. Fixes bug
          18368; bugfix on 0.2.0.8-alpha.
        - When we can't generate a signing key because OfflineMasterKey is
          set, do not imply that we should have been able to load it. Fixes
          bug 18133; bugfix on 0.2.7.2-alpha.
        - When logging a malformed hostname received through socks4, scrub
          it if SafeLogging says we should. Fixes bug 17419; bugfix
          on 0.1.1.16-rc.
    
      o Minor bugfixes (memory safety):
        - Avoid freeing an uninitialized pointer when opening a socket fails
          in get_interface_addresses_ioctl(). Fixes bug 18454; bugfix on
          0.2.3.11-alpha. Reported by toralf and "cypherpunks", patch
          by teor.
        - Fix a memory leak in "tor --list-fingerprint". Fixes part of bug
          18672; bugfix on 0.2.5.1-alpha.
        - Fix a memory leak in tor-gencert. Fixes part of bug 18672; bugfix
          on 0.2.0.1-alpha.
    
      o Minor bugfixes (pluggable transports):
        - Avoid reporting a spurious error when we decide that we don't need
          to terminate a pluggable transport because it has already exited.
          Fixes bug 18686; bugfix on 0.2.5.5-alpha.
    
      o Minor bugfixes (pointer arithmetic):
        - Fix a bug in memarea_alloc() that could have resulted in remote
          heap write access, if Tor had ever passed an unchecked size to
          memarea_alloc(). Fortunately, all the sizes we pass to
          memarea_alloc() are pre-checked to be less than 128 kilobytes.
          Fixes bug 19150; bugfix on 0.2.1.1-alpha. Bug found by
          Guido Vranken.
    
      o Minor bugfixes (private directory):
        - Prevent a race condition when creating private directories. Fixes
          part of bug 17852; bugfix on 0.0.2pre13. Part of ticket 17852.
          Patch from jsturgix. Found with Flawfinder.
    
      o Minor bugfixes (relays):
        - Check that both the ORPort and DirPort (if present) are reachable
          before publishing a relay descriptor. Otherwise, relays publish a
          descriptor with DirPort 0 when the DirPort reachability test takes
          longer than the ORPort reachability test. Fixes bug 18050; bugfix
          on 0.1.0.1-rc. Reported by "starlight", patch by teor.
        - Resolve some edge cases where we might launch an ORPort
          reachability check even when DisableNetwork is set. Noticed while
          fixing bug 18616; bugfix on 0.2.3.9-alpha.
    
      o Minor bugfixes (relays, hidden services):
        - Refuse connection requests to private OR addresses unless
          ExtendAllowPrivateAddresses is set. Previously, tor would connect,
          then refuse to send any cells to a private address. Fixes bugs
          17674 and 8976; bugfix on 0.2.3.21-rc. Patch by teor.
    
      o Minor bugfixes (security, hidden services):
        - Prevent hidden services connecting to client-supplied rendezvous
          addresses that are reserved as internal or multicast. Fixes bug
          8976; bugfix on 0.2.3.21-rc. Patch by dgoulet and teor.
    
      o Minor bugfixes (statistics):
        - Consistently check for overflow in round_*_to_next_multiple_of
          functions, and add unit tests with additional and maximal values.
          Fixes part of bug 13192; bugfix on 0.2.2.1-alpha.
        - Handle edge cases in the laplace functions: avoid division by
          zero, avoid taking the log of zero, and silence clang type
          conversion warnings using round and trunc. Add unit tests for edge
          cases with maximal values. Fixes part of bug 13192; bugfix
          on 0.2.6.2-alpha.
        - We now include consensus downloads via IPv6 in our directory-
          request statistics. Fixes bug 18460; bugfix on 0.2.3.14-alpha.
    
      o Minor bugfixes (test networks, IPv6):
        - Allow internal IPv6 addresses in descriptors in test networks.
          Fixes bug 17153; bugfix on 0.2.3.16-alpha. Patch by teor, reported
          by karsten.
    
      o Minor bugfixes (testing):
        - Check the full results of SHA256 and SHA512 digests in the unit
          tests. Bugfix on 0.2.2.4-alpha. Patch by teor.
        - Fix a memory leak in the ntor test. Fixes bug 17778; bugfix
          on 0.2.4.8-alpha.
        - Fix a small memory leak that would occur when the
          TestingEnableCellStatsEvent option was turned on. Fixes bug 18673;
          bugfix on 0.2.5.2-alpha.
        - Make unit tests pass on IPv6-only systems, and systems without
          localhost addresses (like some FreeBSD jails). Fixes bug 17632;
          bugfix on 0.2.7.3-rc. Patch by teor.
        - The test for log_heartbeat was incorrectly failing in timezones
          with non-integer offsets. Instead of comparing the end of the time
          string against a constant, compare it to the output of
          format_local_iso_time when given the correct input. Fixes bug
          18039; bugfix on 0.2.5.4-alpha.
        - We no longer disable assertions in the unit tests when coverage is
          enabled. Instead, we require you to say --disable-asserts-in-tests
          to the configure script if you need assertions disabled in the
          unit tests (for example, if you want to perform branch coverage).
          Fixes bug 18242; bugfix on 0.2.7.1-alpha.
    
      o Minor bugfixes (time handling):
        - When correcting a corrupt 'struct tm' value, fill in the tm_wday
          field. Otherwise, our unit tests crash on Windows. Fixes bug
          18977; bugfix on 0.2.2.25-alpha.
        - Avoid overflow in tor_timegm when parsing dates in and after 2038
          on platforms with 32-bit time_t. Fixes bug 18479; bugfix on
          0.0.2pre14. Patch by teor.
    
      o Minor bugfixes (tor-gencert):
        - Correctly handle the case where an authority operator enters a
          passphrase but sends an EOF before sending a newline. Fixes bug
          17443; bugfix on 0.2.0.20-rc. Found by junglefowl.
    
      o Code simplification and refactoring:
        - Clean up a little duplicated code in
          crypto_expand_key_material_TAP(). Closes ticket 17587; patch
          from "pfrankw".
        - Decouple the list of streams waiting to be attached to circuits
          from the overall connection list. This change makes it possible to
          attach streams quickly while simplifying Tor's callgraph and
          avoiding O(N) scans of the entire connection list. Closes
          ticket 17590.
        - Extract the more complicated parts of circuit_mark_for_close()
          into a new function that we run periodically before circuits are
          freed. This change removes more than half of the functions
          currently in the "blob". Closes ticket 17218.
        - Move logging of redundant policy entries in
          policies_parse_exit_policy_internal into its own function. Closes
          ticket 17608; patch from "juce".
        - Quote all the string interpolations in configure.ac -- even those
          which we are pretty sure can't contain spaces. Closes ticket
          17744. Patch from zerosion.
        - Remove code for configuring OpenSSL dynamic locks; OpenSSL doesn't
          use them. Closes ticket 17926.
        - Remove specialized code for non-inplace AES_CTR. 99% of our AES is
          inplace, so there's no need to have a separate implementation for
          the non-inplace code. Closes ticket 18258. Patch from Malek.
        - Simplify return types for some crypto functions that can't
          actually fail. Patch from Hassan Alsibyani. Closes ticket 18259.
        - When a direct directory request fails immediately on launch,
          instead of relaunching that request from inside the code that
          launches it, instead mark the connection for teardown. This change
          simplifies Tor's callback and prevents the directory-request
          launching code from invoking itself recursively. Closes
          ticket 17589.
    
      o Documentation:
        - Add a description of the correct use of the '--keygen' command-
          line option. Closes ticket 17583; based on text by 's7r'.
        - Change build messages to refer to "Fedora" instead of "Fedora
          Core", and "dnf" instead of "yum". Closes tickets 18459 and 18426.
          Patches from "icanhasaccount" and "cypherpunks".
        - Document the contents of the 'datadir/keys' subdirectory in the
          manual page. Closes ticket 17621.
        - Document the minimum HeartbeatPeriod value. Closes ticket 15638.
        - Explain actual minima for BandwidthRate. Closes ticket 16382.
        - Fix a minor formatting typo in the manpage. Closes ticket 17791.
        - Mention torspec URL in the manpage and point the reader to it
          whenever we mention a document that belongs in torspce. Fixes
          issue 17392.
        - Stop recommending use of nicknames to identify relays in our
          MapAddress documentation. Closes ticket 18312.
    
      o Removed features:
        - Remove client-side support for connecting to Tor relays running
          versions of Tor before 0.2.3.6-alpha. These relays didn't support
          the v3 TLS handshake protocol, and are no longer allowed on the
          Tor network. Implements the client side of ticket 11150. Based on
          patches by Tom van der Woerdt.
        - We no longer maintain an internal freelist in memarea.c.
          Allocators should be good enough to make this code unnecessary,
          and it's doubtful that it ever had any performance benefit.
    
      o Testing:
        - Add unit tests to check for common RNG failure modes, such as
          returning all zeroes, identical values, or incrementing values
          (OpenSSL's rand_predictable feature). Patch by teor.
        - Always test both ed25519 backends, so that we can be sure that our
          batch-open replacement code works. Part of ticket 16794.
        - Cover dns_resolve_impl() in dns.c with unit tests. Implements a
          portion of ticket 16831.
        - Fix several warnings from clang's address sanitizer produced in
          the unit tests.
        - Log more information when the backtrace tests fail. Closes ticket
          17892. Patch from "cypherpunks."
        - More unit tests for compat_libevent.c, procmon.c, tortls.c,
          util_format.c, directory.c, and options_validate.c. Closes tickets
          17075, 17082, 17084, 17003, and 17076 respectively. Patches from
          Ola Bini.
        - Treat backtrace test failures as expected on FreeBSD until we
          solve bug 17808. Closes ticket 18204.
        - Unit tests for directory_handle_command_get. Closes ticket 17004.
          Patch from Reinaldo de Souza Jr.
    
    
    Changes in version 0.2.7.6 - 2015-12-10
      Tor version 0.2.7.6 fixes a major bug in entry guard selection, as
      well as a minor bug in hidden service reliability.
    
      o Major bugfixes (guard selection):
        - Actually look at the Guard flag when selecting a new directory
          guard. When we implemented the directory guard design, we
          accidentally started treating all relays as if they have the Guard
          flag during guard selection, leading to weaker anonymity and worse
          performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
          by Mohsen Imani.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the December 1 2015 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (compilation):
        - When checking for net/pfvar.h, include netinet/in.h if possible.
          This fixes transparent proxy detection on OpenBSD. Fixes bug
          17551; bugfix on 0.1.2.1-alpha. Patch from "rubiate".
        - Fix a compilation warning with Clang 3.6: Do not check the
          presence of an address which can never be NULL. Fixes bug 17781.
    
      o Minor bugfixes (correctness):
        - When displaying an IPv6 exit policy, include the mask bits
          correctly even when the number is greater than 31. Fixes bug
          16056; bugfix on 0.2.4.7-alpha. Patch from "gturner".
        - The wrong list was used when looking up expired intro points in a
          rend service object, causing what we think could be reachability
          issues for hidden services, and triggering a BUG log. Fixes bug
          16702; bugfix on 0.2.7.2-alpha.
        - Fix undefined behavior in the tor_cert_checksig function. Fixes
          bug 17722; bugfix on 0.2.7.2-alpha.
    
    
    Changes in version 0.2.7.5 - 2015-11-20
      The Tor 0.2.7 release series is dedicated to the memory of Tor user
      and privacy advocate Caspar Bowden (1961-2015). Caspar worked
      tirelessly to advocate human rights regardless of national borders,
      and oppose the encroachments of mass surveillance. He opposed national
      exceptionalism, he brought clarity to legal and policy debates, he
      understood and predicted the impact of mass surveillance on the world,
      and he laid the groundwork for resisting it. While serving on the Tor
      Project's board of directors, he brought us his uncompromising focus
      on technical excellence in the service of humankind. Caspar was an
      inimitable force for good and a wonderful friend. He was kind,
      humorous, generous, gallant, and believed we should protect one
      another without exception. We honor him here for his ideals, his
      efforts, and his accomplishments. Please honor his memory with works
      that would make him proud.
    
      Tor 0.2.7.5 is the first stable release in the Tor 0.2.7 series.
    
      The 0.2.7 series adds a more secure identity key type for relays,
      improves cryptography performance, resolves several longstanding
      hidden-service performance issues, improves controller support for
      hidden services, and includes small bugfixes and performance
      improvements throughout the program. This release series also includes
      more tests than before, and significant simplifications to which parts
      of Tor invoke which others. For a full list of changes, see below.
    
      o New system requirements:
        - Tor no longer includes workarounds to support Libevent versions
          before 1.3e. Libevent 2.0 or later is recommended. Closes
          ticket 15248.
        - Tor no longer supports copies of OpenSSL that are missing support
          for Elliptic Curve Cryptography. (We began using ECC when
          available in 0.2.4.8-alpha, for more safe and efficient key
          negotiation.) In particular, support for at least one of P256 or
          P224 is now required, with manual configuration needed if only
          P224 is available. Resolves ticket 16140.
        - Tor no longer supports versions of OpenSSL before 1.0. (If you are
          on an operating system that has not upgraded to OpenSSL 1.0 or
          later, and you compile Tor from source, you will need to install a
          more recent OpenSSL to link Tor against.) These versions of
          OpenSSL are still supported by the OpenSSL, but the numerous
          cryptographic improvements in later OpenSSL releases makes them a
          clear choice. Resolves ticket 16034.
    
      o Major features (controller):
        - Add the ADD_ONION and DEL_ONION commands that allow the creation
          and management of hidden services via the controller. Closes
          ticket 6411.
        - New "GETINFO onions/current" and "GETINFO onions/detached"
          commands to get information about hidden services created via the
          controller. Part of ticket 6411.
        - New HSFETCH command to launch a request for a hidden service
          descriptor. Closes ticket 14847.
        - New HSPOST command to upload a hidden service descriptor. Closes
          ticket 3523. Patch by "DonnchaC".
    
      o Major features (Ed25519 identity keys, Proposal 220):
        - Add support for offline encrypted Ed25519 master keys. To use this
          feature on your tor relay, run "tor --keygen" to make a new master
          key (or to make a new signing key if you already have a master
          key). Closes ticket 13642.
        - All relays now maintain a stronger identity key, using the Ed25519
          elliptic curve signature format. This master key is designed so
          that it can be kept offline. Relays also generate an online
          signing key, and a set of other Ed25519 keys and certificates.
          These are all automatically regenerated and rotated as needed.
          Implements part of ticket 12498.
        - Directory authorities now vote on Ed25519 identity keys along with
          RSA1024 keys. Implements part of ticket 12498.
        - Directory authorities track which Ed25519 identity keys have been
          used with which RSA1024 identity keys, and do not allow them to
          vary freely. Implements part of ticket 12498.
        - Microdescriptors now include Ed25519 identity keys. Implements
          part of ticket 12498.
        - Add a --newpass option to allow changing or removing the
          passphrase of an encrypted key with tor --keygen. Implements part
          of ticket 16769.
        - Add a new OfflineMasterKey option to tell Tor never to try loading
          or generating a secret Ed25519 identity key. You can use this in
          combination with tor --keygen to manage offline and/or encrypted
          Ed25519 keys. Implements ticket 16944.
        - On receiving a HUP signal, check to see whether the Ed25519
          signing key has changed, and reload it if so. Closes ticket 16790.
        - Significant usability improvements for Ed25519 key management. Log
          messages are better, and the code can recover from far more
          failure conditions. Thanks to "s7r" for reporting and diagnosing
          so many of these!
    
      o Major features (ECC performance):
        - Improve the runtime speed of Ed25519 signature verification by
          using Ed25519-donna's batch verification support. Implements
          ticket 16533.
        - Improve the speed of Ed25519 operations and Curve25519 keypair
          generation when built targeting 32 bit x86 platforms with SSE2
          available. Implements ticket 16535.
        - Improve the runtime speed of Ed25519 operations by using the
          public-domain Ed25519-donna by Andrew M. ("floodyberry").
          Implements ticket 16467.
        - Improve the runtime speed of the ntor handshake by using an
          optimized curve25519 basepoint scalarmult implementation from the
          public-domain Ed25519-donna by Andrew M. ("floodyberry"), based on
          ideas by Adam Langley. Implements ticket 9663.
    
      o Major features (Hidden services):
        - Hidden services, if using the EntryNodes option, are required to
          use more than one EntryNode, in order to avoid a guard discovery
          attack. (This would only affect people who had configured hidden
          services and manually specified the EntryNodes option with a
          single entry-node. The impact was that it would be easy to
          remotely identify the guard node used by such a hidden service.
          See ticket for more information.) Fixes ticket 14917.
        - Add the torrc option HiddenServiceNumIntroductionPoints, to
          specify a fixed number of introduction points. Its maximum value
          is 10 and default is 3. Using this option can increase a hidden
          service's reliability under load, at the cost of making it more
          visible that the hidden service is facing extra load. Closes
          ticket 4862.
        - Remove the adaptive algorithm for choosing the number of
          introduction points, which used to change the number of
          introduction points (poorly) depending on the number of
          connections the HS sees. Closes ticket 4862.
    
      o Major features (onion key cross-certification):
        - Relay descriptors now include signatures of their own identity
          keys, made using the TAP and ntor onion keys. These signatures
          allow relays to prove ownership of their own onion keys. Because
          of this change, microdescriptors will no longer need to include
          RSA identity keys. Implements proposal 228; closes ticket 12499.
    
      o Major bugfixes (client-side privacy, also in 0.2.6.9):
        - Properly separate out each SOCKSPort when applying stream
          isolation. The error occurred because each port's session group
          was being overwritten by a default value when the listener
          connection was initialized. Fixes bug 16247; bugfix on
          0.2.6.3-alpha. Patch by "jojelino".
    
      o Major bugfixes (hidden service clients, stability, also in 0.2.6.10):
        - Stop refusing to store updated hidden service descriptors on a
          client. This reverts commit 9407040c59218 (which indeed fixed bug
          14219, but introduced a major hidden service reachability
          regression detailed in bug 16381). This is a temporary fix since
          we can live with the minor issue in bug 14219 (it just results in
          some load on the network) but the regression of 16381 is too much
          of a setback. First-round fix for bug 16381; bugfix
          on 0.2.6.3-alpha.
    
      o Major bugfixes (hidden services):
        - Revert commit that made directory authorities assign the HSDir
          flag to relays without a DirPort; this was bad because such relays
          can't handle BEGIN_DIR cells. Fixes bug 15850; bugfix
          on 0.2.6.3-alpha.
        - When cannibalizing a circuit for an introduction point, always
          extend to the chosen exit node (creating a 4 hop circuit).
          Previously Tor would use the current circuit exit node, which
          changed the original choice of introduction point, and could cause
          the hidden service to skip excluded introduction points or
          reconnect to a skipped introduction point. Fixes bug 16260; bugfix
          on 0.1.0.1-rc.
    
      o Major bugfixes (memory leaks):
        - Fix a memory leak in ed25519 batch signature checking. Fixes bug
          17398; bugfix on 0.2.6.1-alpha.
    
      o Major bugfixes (open file limit):
        - The open file limit wasn't checked before calling
          tor_accept_socket_nonblocking(), which would make Tor exceed the
          limit. Now, before opening a new socket, Tor validates the open
          file limit just before, and if the max has been reached, return an
          error. Fixes bug 16288; bugfix on 0.1.1.1-alpha.
    
      o Major bugfixes (security, correctness):
        - Fix an error that could cause us to read 4 bytes before the
          beginning of an openssl string. This bug could be used to cause
          Tor to crash on systems with unusual malloc implementations, or
          systems with unusual hardening installed. Fixes bug 17404; bugfix
          on 0.2.3.6-alpha.
    
      o Major bugfixes (stability, also in 0.2.6.10):
        - Stop crashing with an assertion failure when parsing certain kinds
          of malformed or truncated microdescriptors. Fixes bug 16400;
          bugfix on 0.2.6.1-alpha. Found by "torkeln"; fix based on a patch
          by "cypherpunks_backup".
        - Stop random client-side assertion failures that could occur when
          connecting to a busy hidden service, or connecting to a hidden
          service while a NEWNYM is in progress. Fixes bug 16013; bugfix
          on 0.1.0.1-rc.
    
      o Minor features (client, SOCKS):
        - Add GroupWritable and WorldWritable options to unix-socket based
          SocksPort and ControlPort options. These options apply to a single
          socket, and override {Control,Socks}SocketsGroupWritable. Closes
          ticket 15220.
        - Relax the validation done to hostnames in SOCKS5 requests, and
          allow a single trailing '.' to cope with clients that pass FQDNs
          using that syntax to explicitly indicate that the domain name is
          fully-qualified. Fixes bug 16674; bugfix on 0.2.6.2-alpha.
        - Relax the validation of hostnames in SOCKS5 requests, allowing the
          character '_' to appear, in order to cope with domains observed in
          the wild that are serving non-RFC compliant records. Resolves
          ticket 16430.
    
      o Minor features (client-side privacy):
        - New KeepAliveIsolateSOCKSAuth option to indefinitely extend circuit
          lifespan when IsolateSOCKSAuth and streams with SOCKS
          authentication are attached to the circuit. This allows
          applications like TorBrowser to manage circuit lifetime on their
          own. Implements feature 15482.
        - When logging malformed hostnames from SOCKS5 requests, respect
          SafeLogging configuration. Fixes bug 16891; bugfix on 0.1.1.16-rc.
    
      o Minor features (clock-jump tolerance):
        - Recover better when our clock jumps back many hours, like might
          happen for Tails or Whonix users who start with a very wrong
          hardware clock, use Tor to discover a more accurate time, and then
          fix their clock. Resolves part of ticket 8766.
    
      o Minor features (command-line interface):
        - Make --hash-password imply --hush to prevent unnecessary noise.
          Closes ticket 15542. Patch from "cypherpunks".
        - Print a warning whenever we find a relative file path being used
          as torrc option. Resolves issue 14018.
    
      o Minor features (compilation):
        - Give a warning as early as possible when trying to build with an
          unsupported OpenSSL version. Closes ticket 16901.
        - Use C99 variadic macros when the compiler is not GCC. This avoids
          failing compilations on MSVC, and fixes a log-file-based race
          condition in our old workarounds. Original patch from Gisle Vanem.
    
      o Minor features (control protocol):
        - Support network-liveness GETINFO key and NETWORK_LIVENESS event in
          the control protocol. Resolves ticket 15358.
    
      o Minor features (controller):
        - Add DirAuthority lines for default directory authorities to the
          output of the "GETINFO config/defaults" command if not already
          present. Implements ticket 14840.
        - Controllers can now use "GETINFO hs/client/desc/id/..." to
          retrieve items from the client's hidden service descriptor cache.
          Closes ticket 14845.
        - Implement a new controller command "GETINFO status/fresh-relay-
          descs" to fetch a descriptor/extrainfo pair that was generated on
          demand just for the controller's use. Implements ticket 14784.
    
      o Minor features (directory authorities):
        - Directory authorities no longer vote against the "Fast", "Stable",
          and "HSDir" flags just because they were going to vote against
          "Running": if the consensus turns out to be that the router was
          running, then the authority's vote should count. Patch from Peter
          Retzlaff; closes issue 8712.
    
      o Minor features (directory authorities, security, also in 0.2.6.9):
        - The HSDir flag given by authorities now requires the Stable flag.
          For the current network, this results in going from 2887 to 2806
          HSDirs. Also, it makes it harder for an attacker to launch a sybil
          attack by raising the effort for a relay to become Stable to
          require at the very least 7 days, while maintaining the 96 hours
          uptime requirement for HSDir. Implements ticket 8243.
    
      o Minor features (DoS-resistance):
        - Make it harder for attackers to overload hidden services with
          introductions, by blocking multiple introduction requests on the
          same circuit. Resolves ticket 15515.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the October 9 2015 Maxmind GeoLite2
          Country database.
    
      o Minor features (hidden services):
        - Add the new options "HiddenServiceMaxStreams" and
          "HiddenServiceMaxStreamsCloseCircuit" to allow hidden services to
          limit the maximum number of simultaneous streams per circuit, and
          optionally tear down the circuit when the limit is exceeded. Part
          of ticket 16052.
        - Client now uses an introduction point failure cache to know when
          to fetch or keep a descriptor in their cache. Previously, failures
          were recorded implicitly, but not explicitly remembered. Closes
          ticket 16389.
        - Relays need to have the Fast flag to get the HSDir flag. As this
          is being written, we'll go from 2745 HSDirs down to 2342, a ~14%
          drop. This change should make some attacks against the hidden
          service directory system harder. Fixes ticket 15963.
        - Turn on hidden service statistics collection by setting the torrc
          option HiddenServiceStatistics to "1" by default. (This keeps
          track only of the fraction of traffic used by hidden services, and
          the total number of hidden services in existence.) Closes
          ticket 15254.
        - To avoid leaking HS popularity, don't cycle the introduction point
          when we've handled a fixed number of INTRODUCE2 cells but instead
          cycle it when a random number of introductions is reached, thus
          making it more difficult for an attacker to find out the amount of
          clients that have used the introduction point for a specific HS.
          Closes ticket 15745.
    
      o Minor features (logging):
        - Include the Tor version in all LD_BUG log messages, since people
          tend to cut and paste those into the bugtracker. Implements
          ticket 15026.
    
      o Minor features (pluggable transports):
        - When launching managed pluggable transports on Linux systems,
          attempt to have the kernel deliver a SIGTERM on tor exit if the
          pluggable transport process is still running. Resolves
          ticket 15471.
        - When launching managed pluggable transports, setup a valid open
          stdin in the child process that can be used to detect if tor has
          terminated. The "TOR_PT_EXIT_ON_STDIN_CLOSE" environment variable
          can be used by implementations to detect this new behavior.
          Resolves ticket 15435.
    
      o Minor bugfixes (torrc exit policies):
        - In each instance above, usage advice is provided to avoid the
          message. Resolves ticket 16069. Patch by "teor". Fixes part of bug
          16069; bugfix on 0.2.4.7-alpha.
        - In torrc, "accept6 *" and "reject6 *" ExitPolicy lines now only
          produce IPv6 wildcard addresses. Previously they would produce
          both IPv4 and IPv6 wildcard addresses. Patch by "teor". Fixes part
          of bug 16069; bugfix on 0.2.4.7-alpha.
        - When parsing torrc ExitPolicies, we now issue an info-level
          message when expanding an "accept/reject *" line to include both
          IPv4 and IPv6 wildcard addresses. Related to ticket 16069.
        - When parsing torrc ExitPolicies, we now warn for a number of cases
          where the user's intent is likely to differ from Tor's actual
          behavior. These include: using an IPv4 address with an accept6 or
          reject6 line; using "private" on an accept6 or reject6 line; and
          including any ExitPolicy lines after accept *:* or reject *:*.
          Related to ticket 16069.
    
      o Minor bugfixes (command-line interface):
        - When "--quiet" is provided along with "--validate-config", do not
          write anything to stdout on success. Fixes bug 14994; bugfix
          on 0.2.3.3-alpha.
        - When complaining about bad arguments to "--dump-config", use
          stderr, not stdout.
        - Print usage information for --dump-config when it is used without
          an argument. Also, fix the error message to use different wording
          and add newline at the end. Fixes bug 15541; bugfix
          on 0.2.5.1-alpha.
    
      o Minor bugfixes (compilation):
        - Fix compilation of sandbox.c with musl-libc. Fixes bug 17347;
          bugfix on 0.2.5.1-alpha. Patch from 'jamestk'.
        - Repair compilation with the most recent (unreleased, alpha)
          vesions of OpenSSL 1.1. Fixes part of ticket 17237.
    
      o Minor bugfixes (compilation, also in 0.2.6.9):
        - Build with --enable-systemd correctly when libsystemd is
          installed, but systemd is not. Fixes bug 16164; bugfix on
          0.2.6.3-alpha. Patch from Peter Palfrader.
    
      o Minor bugfixes (configuration, unit tests):
        - Only add the default fallback directories when the DirAuthorities,
          AlternateDirAuthority, and FallbackDir directory config options
          are set to their defaults. The default fallback directory list is
          currently empty, this fix will only change tor's behavior when it
          has default fallback directories. Includes unit tests for
          consider_adding_dir_servers(). Fixes bug 15642; bugfix on
          90f6071d8dc0 in 0.2.4.7-alpha. Patch by "teor".
    
      o Minor bugfixes (controller):
        - Add the descriptor ID in each HS_DESC control event. It was
          missing, but specified in control-spec.txt. Fixes bug 15881;
          bugfix on 0.2.5.2-alpha.
    
      o Minor bugfixes (correctness):
        - For correctness, avoid modifying a constant string in
          handle_control_postdescriptor. Fixes bug 15546; bugfix
          on 0.1.1.16-rc.
        - Remove side-effects from tor_assert() calls. This was harmless,
          because we never disable assertions, but it is bad style and
          unnecessary. Fixes bug 15211; bugfix on 0.2.5.5, 0.2.2.36,
          and 0.2.0.10.
        - When calling channel_free_list(), avoid calling smartlist_remove()
          while inside a FOREACH loop. This partially reverts commit
          17356fe7fd96af where the correct SMARTLIST_DEL_CURRENT was
          incorrectly removed. Fixes bug 16924; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (crypto error-handling, also in 0.2.6.10):
        - Check for failures from crypto_early_init, and refuse to continue.
          A previous typo meant that we could keep going with an
          uninitialized crypto library, and would have OpenSSL initialize
          its own PRNG. Fixes bug 16360; bugfix on 0.2.5.2-alpha, introduced
          when implementing ticket 4900. Patch by "teor".
    
      o Minor bugfixes (hidden service):
        - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
          a client authorized hidden service. Fixes bug 15823; bugfix
          on 0.2.1.6-alpha.
        - Remove an extraneous newline character from the end of hidden
          service descriptors. Fixes bug 15296; bugfix on 0.2.0.10-alpha.
    
      o Minor bugfixes (Linux seccomp2 sandbox):
        - Use the sandbox in tor_open_cloexec whether or not O_CLOEXEC is
          defined. Patch by "teor". Fixes bug 16515; bugfix on 0.2.3.1-alpha.
        - Allow bridge authorities to run correctly under the seccomp2
          sandbox. Fixes bug 16964; bugfix on 0.2.5.1-alpha.
        - Add the "hidserv-stats" filename to our sandbox filter for the
          HiddenServiceStatistics option to work properly. Fixes bug 17354;
          bugfix on 0.2.6.2-alpha. Patch from David Goulet.
    
      o Minor bugfixes (Linux seccomp2 sandbox, also in 0.2.6.10):
        - Allow pipe() and pipe2() syscalls in the seccomp2 sandbox: we need
          these when eventfd2() support is missing. Fixes bug 16363; bugfix
          on 0.2.6.3-alpha. Patch from "teor".
    
      o Minor bugfixes (Linux seccomp2 sandbox, also in 0.2.6.9):
        - Allow systemd connections to work with the Linux seccomp2 sandbox
          code. Fixes bug 16212; bugfix on 0.2.6.2-alpha. Patch by
          Peter Palfrader.
        - Fix sandboxing to work when running as a relay, by allowing the
          renaming of secret_id_key, and allowing the eventfd2 and futex
          syscalls. Fixes bug 16244; bugfix on 0.2.6.1-alpha. Patch by
          Peter Palfrader.
    
      o Minor bugfixes (logging):
        - When building Tor under Clang, do not include an extra set of
          parentheses in log messages that include function names. Fixes bug
          15269; bugfix on every released version of Tor when compiled with
          recent enough Clang.
    
      o Minor bugfixes (network):
        - When attempting to use fallback technique for network interface
          lookup, disregard loopback and multicast addresses since they are
          unsuitable for public communications.
    
      o Minor bugfixes (open file limit):
        - Fix set_max_file_descriptors() to set by default the max open file
          limit to the current limit when setrlimit() fails. Fixes bug
          16274; bugfix on tor- 0.2.0.10-alpha. Patch by dgoulet.
    
      o Minor bugfixes (portability):
        - Check correctly for Windows socket errors in the workqueue
          backend. Fixes bug 16741; bugfix on 0.2.6.3-alpha.
        - Try harder to normalize the exit status of the Tor process to the
          standard-provided range. Fixes bug 16975; bugfix on every version
          of Tor ever.
        - Use libexecinfo on FreeBSD to enable backtrace support. Fixes part
          of bug 17151; bugfix on 0.2.5.2-alpha. Patch from Marcin Cieślak.
    
      o Minor bugfixes (relay):
        - Ensure that worker threads actually exit when a fatal error or
          shutdown is indicated. This fix doesn't currently affect the
          behavior of Tor, because Tor workers never indicates fatal error
          or shutdown except in the unit tests. Fixes bug 16868; bugfix
          on 0.2.6.3-alpha.
        - Fix a rarely-encountered memory leak when failing to initialize
          the thread pool. Fixes bug 16631; bugfix on 0.2.6.3-alpha. Patch
          from "cypherpunks".
        - Unblock threads before releasing the work queue mutex to ensure
          predictable scheduling behavior. Fixes bug 16644; bugfix
          on 0.2.6.3-alpha.
    
      o Minor bugfixes (security, exit policies):
        - ExitPolicyRejectPrivate now also rejects the relay's published
          IPv6 address (if any), and any publicly routable IPv4 or IPv6
          addresses on any local interfaces. ticket 17027. Patch by "teor".
          Fixes bug 17027; bugfix on 0.2.0.11-alpha.
    
      o Minor bugfixes (statistics):
        - Disregard the ConnDirectionStatistics torrc options when Tor is
          not a relay since in that mode of operation no sensible data is
          being collected and because Tor might run into measurement hiccups
          when running as a client for some time, then becoming a relay.
          Fixes bug 15604; bugfix on 0.2.2.35.
    
      o Minor bugfixes (systemd):
        - Tor's systemd unit file no longer contains extraneous spaces.
          These spaces would sometimes confuse tools like deb-systemd-
          helper. Fixes bug 16162; bugfix on 0.2.5.5-alpha.
    
      o Minor bugfixes (test networks):
        - When self-testing reachability, use ExtendAllowPrivateAddresses to
          determine if local/private addresses imply reachability. The
          previous fix used TestingTorNetwork, which implies
          ExtendAllowPrivateAddresses, but this excluded rare configurations
          where ExtendAllowPrivateAddresses is set but TestingTorNetwork is
          not. Fixes bug 15771; bugfix on 0.2.6.1-alpha. Patch by "teor",
          issue discovered by CJ Ess.
    
      o Minor bugfixes (tests, also in 0.2.6.9):
        - Fix a crash in the unit tests when built with MSVC2013. Fixes bug
          16030; bugfix on 0.2.6.2-alpha. Patch from "NewEraCracker".
    
      o Code simplification and refactoring:
        - Change the function that's called when we need to retry all
          downloads so that it only reschedules the downloads to happen
          immediately, rather than launching them all at once itself. This
          further simplifies Tor's callgraph.
        - Define WINVER and _WIN32_WINNT centrally, in orconfig.h, in order
          to ensure they remain consistent and visible everywhere.
        - Move some format-parsing functions out of crypto.c and
          crypto_curve25519.c into crypto_format.c and/or util_format.c.
        - Move the client-only parts of init_keys() into a separate
          function. Closes ticket 16763.
        - Move the hacky fallback code out of get_interface_address6() into
          separate function and get it covered with unit-tests. Resolves
          ticket 14710.
        - Refactor hidden service client-side cache lookup to intelligently
          report its various failure cases, and disentangle failure cases
          involving a lack of introduction points. Closes ticket 14391.
        - Remove some vestigial workarounds for the MSVC6 compiler. We
          haven't supported that in ages.
        - Remove the unused "nulterminate" argument from buf_pullup().
        - Simplify the microdesc_free() implementation so that it no longer
          appears (to code analysis tools) to potentially invoke a huge
          suite of other microdesc functions.
        - Simply the control graph further by deferring the inner body of
          directory_all_unreachable() into a callback. Closes ticket 16762.
        - The link authentication code has been refactored for better
          testability and reliability. It now uses code generated with the
          "trunnel" binary encoding generator, to reduce the risk of bugs
          due to programmer error. Done as part of ticket 12498.
        - Treat the loss of an owning controller as equivalent to a SIGTERM
          signal. This removes a tiny amount of duplicated code, and
          simplifies our callgraph. Closes ticket 16788.
        - Use our own Base64 encoder instead of OpenSSL's, to allow more
          control over the output. Part of ticket 15652.
        - When generating an event to send to the controller, we no longer
          put the event over the network immediately. Instead, we queue
          these events, and use a Libevent callback to deliver them. This
          change simplifies Tor's callgraph by reducing the number of
          functions from which all other Tor functions are reachable. Closes
          ticket 16695.
        - Wrap Windows-only C files inside '#ifdef _WIN32' so that tools
          that try to scan or compile every file on Unix won't decide that
          they are broken.
    
      o Documentation:
        - Fix capitalization of SOCKS in sample torrc. Closes ticket 15609.
        - Improve the descriptions of statistics-related torrc options in
          the manpage to describe rationale and possible uses cases. Fixes
          issue 15550.
        - Improve the layout and formatting of ./configure --help messages.
          Closes ticket 15024. Patch from "cypherpunks".
        - Include a specific and (hopefully) accurate documentation of the
          torrc file's meta-format in doc/torrc_format.txt. This is mainly
          of interest to people writing programs to parse or generate torrc
          files. This document is not a commitment to long-term
          compatibility; some aspects of the current format are a bit
          ridiculous. Closes ticket 2325.
        - Include the TUNING document in our source tarball. It is referred
          to in the ChangeLog and an error message. Fixes bug 16929; bugfix
          on 0.2.6.1-alpha.
        - Note that HiddenServicePorts can take a unix domain socket. Closes
          ticket 17364.
        - Recommend a 40 GB example AccountingMax in torrc.sample rather
          than a 4 GB max. Closes ticket 16742.
        - Standardize on the term "server descriptor" in the manual page.
          Previously, we had used "router descriptor", "server descriptor",
          and "relay descriptor" interchangeably. Part of ticket 14987.
        - Advise users on how to configure separate IPv4 and IPv6 exit
          policies in the manpage and sample torrcs. Related to ticket 16069.
        - Fix an error in the manual page and comments for
          TestingDirAuthVoteHSDir[IsStrict], which suggested that a HSDir
          required "ORPort connectivity". While this is true, it is in no
          way unique to the HSDir flag. Of all the flags, only HSDirs need a
          DirPort configured in order for the authorities to assign that
          particular flag. Patch by "teor". Fixed as part of 14882; bugfix
          on 0.2.6.3-alpha.
        - Fix the usage message of tor-resolve(1) so that it no longer lists
          the removed -F option. Fixes bug 16913; bugfix on 0.2.2.28-beta.
    
      o Removed code:
        - Remove `USE_OPENSSL_BASE64` and the corresponding fallback code
          and always use the internal Base64 decoder. The internal decoder
          has been part of tor since 0.2.0.10-alpha, and no one should
          be using the OpenSSL one. Part of ticket 15652.
        - Remove the 'tor_strclear()' function; use memwipe() instead.
          Closes ticket 14922.
        - Remove the code that would try to aggressively flush controller
          connections while writing to them. This code was introduced in
          0.1.2.7-alpha, in order to keep output buffers from exceeding
          their limits. But there is no longer a maximum output buffer size,
          and flushing data in this way caused some undesirable recursions
          in our call graph. Closes ticket 16480.
        - The internal pure-C tor-fw-helper tool is now removed from the Tor
          distribution, in favor of the pure-Go clone available from
          https://gitweb.torproject.org/tor-fw-helper.git/ . The libraries
          used by the C tor-fw-helper are not, in our opinion, very
          confidence- inspiring in their secure-programming techniques.
          Closes ticket 13338.
    
      o Removed features:
        - Remove the (seldom-used) DynamicDHGroups feature. For anti-
          fingerprinting we now recommend pluggable transports; for forward-
          secrecy in TLS, we now use the P-256 group. Closes ticket 13736.
        - Remove the HidServDirectoryV2 option. Now all relays offer to
          store hidden service descriptors. Related to 16543.
        - Remove the VoteOnHidServDirectoriesV2 option, since all
          authorities have long set it to 1. Closes ticket 16543.
        - Remove the undocumented "--digests" command-line option. It
          complicated our build process, caused subtle build issues on
          multiple platforms, and is now redundant since we started
          including git version identifiers. Closes ticket 14742.
        - Tor no longer contains checks for ancient directory cache versions
          that didn't know about microdescriptors.
        - Tor no longer contains workarounds for stat files generated by
          super-old versions of Tor that didn't choose guards sensibly.
    
      o Testing:
        - The test-network.sh script now supports performance testing.
          Requires corresponding chutney performance testing changes. Patch
          by "teor". Closes ticket 14175.
        - Add a new set of callgraph analysis scripts that use clang to
          produce a list of which Tor functions are reachable from which
          other Tor functions. We're planning to use these to help simplify
          our code structure by identifying illogical dependencies.
        - Add new 'test-full' and 'test-full-online' targets to run all
          tests, including integration tests with stem and chutney.
        - Autodetect CHUTNEY_PATH if the chutney and Tor sources are side-
          by-side in the same parent directory. Closes ticket 16903. Patch
          by "teor".
        - Document use of coverity, clang static analyzer, and clang dynamic
          undefined behavior and address sanitizers in doc/HACKING. Include
          detailed usage instructions in the blacklist. Patch by "teor".
          Closes ticket 15817.
        - Make "bridges+hs" the default test network. This tests almost all
          tor functionality during make test-network, while allowing tests
          to succeed on non-IPv6 systems. Requires chutney commit 396da92 in
          test-network-bridges-hs. Closes tickets 16945 (tor) and 16946
          (chutney). Patches by "teor".
        - Make the test-workqueue test work on Windows by initializing the
          network before we begin.
        - New make target (make test-network-all) to run multiple applicable
          chutney test cases. Patch from Teor; closes 16953.
        - Now that OpenSSL has its own scrypt implementation, add an unit
          test that checks for interoperability between libscrypt_scrypt()
          and OpenSSL's EVP_PBE_scrypt() so that we could not use libscrypt
          and rely on EVP_PBE_scrypt() whenever possible. Resolves
          ticket 16189.
        - The link authentication protocol code now has extensive tests.
        - The relay descriptor signature testing code now has
          extensive tests.
        - The test_workqueue program now runs faster, and is enabled by
          default as a part of "make check".
        - Unit test dns_resolve(), dns_clip_ttl() and dns_get_expiry_ttl()
          functions in dns.c. Implements a portion of ticket 16831.
        - Use environment variables rather than autoconf substitutions to
          send variables from the build system to the test scripts. This
          change should be easier to maintain, and cause 'make distcheck' to
          work better than before. Fixes bug 17148.
        - When building Tor with testing coverage enabled, run Chutney tests
          (if any) using the 'tor-cov' coverage binary.
        - When running test-network or test-stem, check for the absence of
          stem/chutney before doing any build operations.
        - Add a test to verify that the compiler does not eliminate our
          memwipe() implementation. Closes ticket 15377.
        - Add make rule `check-changes` to verify the format of changes
          files. Closes ticket 15180.
        - Add unit tests for control_event_is_interesting(). Add a compile-
          time check that the number of events doesn't exceed the capacity
          of control_event_t.event_mask. Closes ticket 15431, checks for
          bugs similar to 13085. Patch by "teor".
        - Command-line argument tests moved to Stem. Resolves ticket 14806.
        - Integrate the ntor, backtrace, and zero-length keys tests into the
          automake test suite. Closes ticket 15344.
        - Remove assertions during builds to determine Tor's test coverage.
          We don't want to trigger these even in assertions, so including
          them artificially makes our branch coverage look worse than it is.
          This patch provides the new test-stem-full and coverage-html-full
          configure options. Implements ticket 15400.
        - New TestingDirAuthVote{Exit,Guard,HSDir}IsStrict flags to
          explicitly manage consensus flags in testing networks. Patch by
          "robgjansen", modified by "teor". Implements part of ticket 14882.
        - Check for matching value in server response in ntor_ref.py. Fixes
          bug 15591; bugfix on 0.2.4.8-alpha. Reported and fixed
          by "joelanders".
        - Set the severity correctly when testing
          get_interface_addresses_ifaddrs() and
          get_interface_addresses_win32(), so that the tests fail gracefully
          instead of triggering an assertion. Fixes bug 15759; bugfix on
          0.2.6.3-alpha. Reported by Nicolas Derive.
    
    Changes in version 0.2.6.10 - 2015-07-12
      Tor version 0.2.6.10 fixes some significant stability and hidden
      service client bugs, bulletproofs the cryptography init process, and
      fixes a bug when using the sandbox code with some older versions of
      Linux. Everyone running an older version, especially an older version
      of 0.2.6, should upgrade.
    
      o Major bugfixes (hidden service clients, stability):
        - Stop refusing to store updated hidden service descriptors on a
          client. This reverts commit 9407040c59218 (which indeed fixed bug
          14219, but introduced a major hidden service reachability
          regression detailed in bug 16381). This is a temporary fix since
          we can live with the minor issue in bug 14219 (it just results in
          some load on the network) but the regression of 16381 is too much
          of a setback. First-round fix for bug 16381; bugfix
          on 0.2.6.3-alpha.
    
      o Major bugfixes (stability):
        - Stop crashing with an assertion failure when parsing certain kinds
          of malformed or truncated microdescriptors. Fixes bug 16400;
          bugfix on 0.2.6.1-alpha. Found by "torkeln"; fix based on a patch
          by "cypherpunks_backup".
        - Stop random client-side assertion failures that could occur when
          connecting to a busy hidden service, or connecting to a hidden
          service while a NEWNYM is in progress. Fixes bug 16013; bugfix
          on 0.1.0.1-rc.
    
      o Minor features (geoip):
        - Update geoip to the June 3 2015 Maxmind GeoLite2 Country database.
        - Update geoip6 to the June 3 2015 Maxmind GeoLite2 Country database.
    
      o Minor bugfixes (crypto error-handling):
        - Check for failures from crypto_early_init, and refuse to continue.
          A previous typo meant that we could keep going with an
          uninitialized crypto library, and would have OpenSSL initialize
          its own PRNG. Fixes bug 16360; bugfix on 0.2.5.2-alpha, introduced
          when implementing ticket 4900. Patch by "teor".
    
      o Minor bugfixes (Linux seccomp2 sandbox):
        - Allow pipe() and pipe2() syscalls in the seccomp2 sandbox: we need
          these when eventfd2() support is missing. Fixes bug 16363; bugfix
          on 0.2.6.3-alpha. Patch from "teor".
    
    
    Changes in version 0.2.6.9 - 2015-06-11
      Tor 0.2.6.9 fixes a regression in the circuit isolation code, increases the
      requirements for receiving an HSDir flag, and addresses some other small
      bugs in the systemd and sandbox code. Clients using circuit isolation
      should upgrade; all directory authorities should upgrade.
    
      o Major bugfixes (client-side privacy):
        - Properly separate out each SOCKSPort when applying stream
          isolation. The error occurred because each port's session group was
          being overwritten by a default value when the listener connection
          was initialized. Fixes bug 16247; bugfix on 0.2.6.3-alpha. Patch
          by "jojelino".
    
      o Minor feature (directory authorities, security):
        - The HSDir flag given by authorities now requires the Stable flag.
          For the current network, this results in going from 2887 to 2806
          HSDirs. Also, it makes it harder for an attacker to launch a sybil
          attack by raising the effort for a relay to become Stable which
          takes at the very least 7 days to do so and by keeping the 96
          hours uptime requirement for HSDir. Implements ticket 8243.
    
      o Minor bugfixes (compilation):
        - Build with --enable-systemd correctly when libsystemd is
          installed, but systemd is not. Fixes bug 16164; bugfix on
          0.2.6.3-alpha. Patch from Peter Palfrader.
    
      o Minor bugfixes (Linux seccomp2 sandbox):
        - Fix sandboxing to work when running as a relaymby renaming of
          secret_id_key, and allowing the eventfd2 and futex syscalls. Fixes
          bug 16244; bugfix on 0.2.6.1-alpha. Patch by Peter Palfrader.
        - Allow systemd connections to work with the Linux seccomp2 sandbox
          code. Fixes bug 16212; bugfix on 0.2.6.2-alpha. Patch by
          Peter Palfrader.
    
      o Minor bugfixes (tests):
        - Fix a crash in the unit tests when built with MSVC2013. Fixes bug
          16030; bugfix on 0.2.6.2-alpha. Patch from "NewEraCracker".
    
    
    Changes in version 0.2.6.8 - 2015-05-21
      Tor 0.2.6.8 fixes a bit of dodgy code in parsing INTRODUCE2 cells, and
      fixes an authority-side bug in assigning the HSDir flag. All directory
      authorities should upgrade.
    
      o Major bugfixes (hidden services, backport from 0.2.7.1-alpha):
        - Revert commit that made directory authorities assign the HSDir
          flag to relays without a DirPort; this was bad because such relays
          can't handle BEGIN_DIR cells. Fixes bug 15850; bugfix
          on 0.2.6.3-alpha.
    
      o Minor bugfixes (hidden service, backport from 0.2.7.1-alpha):
        - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
          a client authorized hidden service. Fixes bug 15823; bugfix
          on 0.2.1.6-alpha.
    
      o Minor features (geoip):
        - Update geoip to the April 8 2015 Maxmind GeoLite2 Country database.
        - Update geoip6 to the April 8 2015 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.6.7 - 2015-04-06
      Tor 0.2.6.7 fixes two security issues that could be used by an
      attacker to crash hidden services, or crash clients visiting hidden
      services. Hidden services should upgrade as soon as possible; clients
      should upgrade whenever packages become available.
    
      This release also contains two simple improvements to make hidden
      services a bit less vulnerable to denial-of-service attacks.
    
      o Major bugfixes (security, hidden service):
        - Fix an issue that would allow a malicious client to trigger an
          assertion failure and halt a hidden service. Fixes bug 15600;
          bugfix on 0.2.1.6-alpha. Reported by "disgleirio".
        - Fix a bug that could cause a client to crash with an assertion
          failure when parsing a malformed hidden service descriptor. Fixes
          bug 15601; bugfix on 0.2.1.5-alpha. Found by "DonnchaC".
    
      o Minor features (DoS-resistance, hidden service):
        - Introduction points no longer allow multiple INTRODUCE1 cells to
          arrive on the same circuit. This should make it more expensive for
          attackers to overwhelm hidden services with introductions.
          Resolves ticket 15515.
        - Decrease the amount of reattempts that a hidden service performs
          when its rendezvous circuits fail. This reduces the computational
          cost for running a hidden service under heavy load. Resolves
          ticket 11447.
    
    
    Changes in version 0.2.5.12 - 2015-04-06
      Tor 0.2.5.12 backports two fixes from 0.2.6.7 for security issues that
      could be used by an attacker to crash hidden services, or crash clients
      visiting hidden services. Hidden services should upgrade as soon as
      possible; clients should upgrade whenever packages become available.
    
      This release also backports a simple improvement to make hidden
      services a bit less vulnerable to denial-of-service attacks.
    
      o Major bugfixes (security, hidden service):
        - Fix an issue that would allow a malicious client to trigger an
          assertion failure and halt a hidden service. Fixes bug 15600;
          bugfix on 0.2.1.6-alpha. Reported by "disgleirio".
        - Fix a bug that could cause a client to crash with an assertion
          failure when parsing a malformed hidden service descriptor. Fixes
          bug 15601; bugfix on 0.2.1.5-alpha. Found by "DonnchaC".
    
      o Minor features (DoS-resistance, hidden service):
        - Introduction points no longer allow multiple INTRODUCE1 cells to
          arrive on the same circuit. This should make it more expensive for
          attackers to overwhelm hidden services with introductions.
          Resolves ticket 15515.
    
    
    Changes in version 0.2.4.27 - 2015-04-06
      Tor 0.2.4.27 backports two fixes from 0.2.6.7 for security issues that
      could be used by an attacker to crash hidden services, or crash clients
      visiting hidden services. Hidden services should upgrade as soon as
      possible; clients should upgrade whenever packages become available.
    
      This release also backports a simple improvement to make hidden
      services a bit less vulnerable to denial-of-service attacks.
    
      o Major bugfixes (security, hidden service):
        - Fix an issue that would allow a malicious client to trigger an
          assertion failure and halt a hidden service. Fixes bug 15600;
          bugfix on 0.2.1.6-alpha. Reported by "disgleirio".
        - Fix a bug that could cause a client to crash with an assertion
          failure when parsing a malformed hidden service descriptor. Fixes
          bug 15601; bugfix on 0.2.1.5-alpha. Found by "DonnchaC".
    
      o Minor features (DoS-resistance, hidden service):
        - Introduction points no longer allow multiple INTRODUCE1 cells to
          arrive on the same circuit. This should make it more expensive for
          attackers to overwhelm hidden services with introductions.
          Resolves ticket 15515.
    
    
    Changes in version 0.2.6.6 - 2015-03-24
      Tor 0.2.6.6 is the first stable release in the 0.2.6 series.
    
      It adds numerous safety, security, correctness, and performance
      improvements. Client programs can be configured to use more kinds of
      sockets, AutomapHosts works better, the multithreading backend is
      improved, cell transmission is refactored, test coverage is much
      higher, more denial-of-service attacks are handled, guard selection is
      improved to handle long-term guards better, pluggable transports
      should work a bit better, and some annoying hidden service performance
      bugs should be addressed.
    
      o New compiler and system requirements:
        - Tor 0.2.6.x requires that your compiler support more of the C99
          language standard than before. The 'configure' script now detects
          whether your compiler supports C99 mid-block declarations and
          designated initializers. If it does not, Tor will not compile.
    
          We may revisit this requirement if it turns out that a significant
          number of people need to build Tor with compilers that don't
          bother implementing a 15-year-old standard. Closes ticket 13233.
        - Tor no longer supports systems without threading support. When we
          began working on Tor, there were several systems that didn't have
          threads, or where the thread support wasn't able to run the
          threads of a single process on multiple CPUs. That no longer
          holds: every system where Tor needs to run well now has threading
          support. Resolves ticket 12439.
    
      o Deprecated versions and removed support:
        - Tor relays older than 0.2.4.18-rc are no longer allowed to
          advertise themselves on the network. Closes ticket 13555.
        - Tor clients no longer support connecting to hidden services
          running on Tor 0.2.2.x and earlier; the Support022HiddenServices
          option has been removed. (There shouldn't be any hidden services
          running these versions on the network.) Closes ticket 7803.
    
      o Directory authority changes:
        - The directory authority Faravahar has a new IP address. This
          closes ticket 14487.
        - Remove turtles as a directory authority.
        - Add longclaw as a new (v3) directory authority. This implements
          ticket 13296. This keeps the directory authority count at 9.
    
      o Major features (bridges):
        - Expose the outgoing upstream HTTP/SOCKS proxy to pluggable
          transports if they are configured via the "TOR_PT_PROXY"
          environment variable. Implements proposal 232. Resolves
          ticket 8402.
    
      o Major features (changed defaults):
        - Prevent relay operators from unintentionally running exits: When a
          relay is configured as an exit node, we now warn the user unless
          the "ExitRelay" option is set to 1. We warn even more loudly if
          the relay is configured with the default exit policy, since this
          can indicate accidental misconfiguration. Setting "ExitRelay 0"
          stops Tor from running as an exit relay. Closes ticket 10067.
    
      o Major features (client performance, hidden services):
        - Allow clients to use optimistic data when connecting to a hidden
          service, which should remove a round-trip from hidden service
          initialization. See proposal 181 for details. Implements
          ticket 13211.
    
      o Major features (directory system):
        - Upon receiving an unparseable directory object, if its digest
          matches what we expected, then don't try to download it again.
          Previously, when we got a descriptor we didn't like, we would keep
          trying to download it over and over. Closes ticket 11243.
        - When downloading server- or microdescriptors from a directory
          server, we no longer launch multiple simultaneous requests to the
          same server. This reduces load on the directory servers,
          especially when directory guards are in use. Closes ticket 9969.
        - When downloading server- or microdescriptors over a tunneled
          connection, do not limit the length of our requests to what the
          Squid proxy is willing to handle. Part of ticket 9969.
        - Authorities can now vote on the correct digests and latest
          versions for different software packages. This allows packages
          that include Tor to use the Tor authority system as a way to get
          notified of updates and their correct digests. Implements proposal
          227. Closes ticket 10395.
    
      o Major features (guards):
        - Introduce the Guardfraction feature to improves load balancing on
          guard nodes. Specifically, it aims to reduce the traffic gap that
          guard nodes experience when they first get the Guard flag. This is
          a required step if we want to increase the guard lifetime to 9
          months or greater.  Closes ticket 9321.
    
      o Major features (hidden services):
        - Make HS port scanning more difficult by immediately closing the
          circuit when a user attempts to connect to a nonexistent port.
          Closes ticket 13667.
        - Add a HiddenServiceStatistics option that allows Tor relays to
          gather and publish statistics about the overall size and volume of
          hidden service usage. Specifically, when this option is turned on,
          an HSDir will publish an approximate number of hidden services
          that have published descriptors to it the past 24 hours. Also, if
          a relay has acted as a hidden service rendezvous point, it will
          publish the approximate amount of rendezvous cells it has relayed
          the past 24 hours. The statistics themselves are obfuscated so
          that the exact values cannot be derived. For more details see
          proposal 238, "Better hidden service stats from Tor relays". This
          feature is currently disabled by default. Implements feature 13192.
    
      o Major features (performance):
        - Make the CPU worker implementation more efficient by avoiding the
          kernel and lengthening pipelines. The original implementation used
          sockets to transfer data from the main thread to the workers, and
          didn't allow any thread to be assigned more than a single piece of
          work at once. The new implementation avoids communications
          overhead by making requests in shared memory, avoiding kernel IO
          where possible, and keeping more requests in flight at once.
          Implements ticket 9682.
    
      o Major features (relay):
        - Raise the minimum acceptable configured bandwidth rate for bridges
          to 50 KiB/sec and for relays to 75 KiB/sec. (The old values were
          20 KiB/sec.) Closes ticket 13822.
        - Complete revision of the code that relays use to decide which cell
          to send next. Formerly, we selected the best circuit to write on
          each channel, but we didn't select among channels in any
          sophisticated way. Now, we choose the best circuits globally from
          among those whose channels are ready to deliver traffic.
    
          This patch implements a new inter-cmux comparison API, a global
          high/low watermark mechanism and a global scheduler loop for
          transmission prioritization across all channels as well as among
          circuits on one channel. This schedule is currently tuned to
          (tolerantly) avoid making changes in network performance, but it
          should form the basis for major circuit performance increases in
          the future. Code by Andrea; tuning by Rob Jansen; implements
          ticket 9262.
    
      o Major features (sample torrc):
        - Add a new, infrequently-changed "torrc.minimal". This file is
          similar to torrc.sample, but it will change as infrequently as
          possible, for the benefit of users whose systems prompt them for
          intervention whenever a default configuration file is changed.
          Making this change allows us to update torrc.sample to be a more
          generally useful "sample torrc".
    
      o Major features (security, unix domain sockets):
        - Allow SocksPort to be an AF_UNIX Unix Domain Socket. Now high risk
          applications can reach Tor without having to create AF_INET or
          AF_INET6 sockets, meaning they can completely disable their
          ability to make non-Tor network connections. To create a socket of
          this type, use "SocksPort unix:/path/to/socket". Implements
          ticket 12585.
        - Support mapping hidden service virtual ports to AF_UNIX sockets.
          The syntax is "HiddenServicePort 80 unix:/path/to/socket".
          Implements ticket 11485.
    
      o Major bugfixes (client, automap):
        - Repair automapping with IPv6 addresses. This automapping should
          have worked previously, but one piece of debugging code that we
          inserted to detect a regression actually caused the regression to
          manifest itself again. Fixes bug 13811 and bug 12831; bugfix on
          0.2.4.7-alpha. Diagnosed and fixed by Francisco Blas
          Izquierdo Riera.
    
      o Major bugfixes (crash, OSX, security):
        - Fix a remote denial-of-service opportunity caused by a bug in
          OSX's _strlcat_chk() function. Fixes bug 15205; bug first appeared
          in OSX 10.9.
    
      o Major bugfixes (directory authorities):
        - Do not assign the HSDir flag to relays if they are not Valid, or
          currently hibernating. Fixes 12573; bugfix on 0.2.0.10-alpha.
    
      o Major bugfixes (directory bandwidth performance):
        - Don't flush the zlib buffer aggressively when compressing
          directory information for clients. This should save about 7% of
          the bandwidth currently used for compressed descriptors and
          microdescriptors. Fixes bug 11787; bugfix on 0.1.1.23.
    
      o Major bugfixes (exit node stability):
        - Fix an assertion failure that could occur under high DNS load.
          Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr";
          diagnosed and fixed by "cypherpunks".
    
      o Major bugfixes (FreeBSD IPFW transparent proxy):
        - Fix address detection with FreeBSD transparent proxies, when
          "TransProxyType ipfw" is in use. Fixes bug 15064; bugfix
          on 0.2.5.4-alpha.
    
      o Major bugfixes (hidden services):
        - When closing an introduction circuit that was opened in parallel
          with others, don't mark the introduction point as unreachable.
          Previously, the first successful connection to an introduction
          point would make the other introduction points get marked as
          having timed out. Fixes bug 13698; bugfix on 0.0.6rc2.
    
      o Major bugfixes (Linux seccomp2 sandbox):
        - Upon receiving sighup with the seccomp2 sandbox enabled, do not
          crash during attempts to call wait4. Fixes bug 15088; bugfix on
          0.2.5.1-alpha. Patch from "sanic".
    
      o Major bugfixes (mixed relay-client operation):
        - When running as a relay and client at the same time (not
          recommended), if we decide not to use a new guard because we want
          to retry older guards, only close the locally-originating circuits
          passing through that guard. Previously we would close all the
          circuits through that guard. Fixes bug 9819; bugfix on
          0.2.1.1-alpha. Reported by "skruffy".
    
      o Major bugfixes (pluggable transports):
        - Initialize the extended OR Port authentication cookie before
          launching pluggable transports. This prevents a race condition
          that occurred when server-side pluggable transports would cache the
          authentication cookie before it has been (re)generated. Fixes bug
          15240; bugfix on 0.2.5.1-alpha.
    
      o Major bugfixes (relay, stability, possible security):
        - Fix a bug that could lead to a relay crashing with an assertion
          failure if a buffer of exactly the wrong layout is passed to
          buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on
          0.2.0.10-alpha. Patch from "cypherpunks".
        - Do not assert if the 'data' pointer on a buffer is advanced to the
          very end of the buffer; log a BUG message instead. Only assert if
          it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.
    
      o Minor features (build):
        - New --disable-system-torrc compile-time option to prevent Tor from
          looking for the system-wide torrc or torrc-defaults files.
          Resolves ticket 13037.
    
      o Minor features (client):
        - Clients are now willing to send optimistic data (before they
          receive a 'connected' cell) to relays of any version. (Relays
          without support for optimistic data are no longer supported on the
          Tor network.) Resolves ticket 13153.
    
      o Minor features (client):
        - Validate hostnames in SOCKS5 requests more strictly. If SafeSocks
          is enabled, reject requests with IP addresses as hostnames.
          Resolves ticket 13315.
    
      o Minor features (controller):
        - Add a "SIGNAL HEARTBEAT" controller command that tells Tor to
          write an unscheduled heartbeat message to the log. Implements
          feature 9503.
        - Include SOCKS_USERNAME and SOCKS_PASSWORD values in controller
          events so controllers can observe circuit isolation inputs. Closes
          ticket 8405.
        - ControlPort now supports the unix:/path/to/socket syntax as an
          alternative to the ControlSocket option, for consistency with
          SocksPort and HiddenServicePort. Closes ticket 14451.
        - New "GETINFO bw-event-cache" to get information about recent
          bandwidth events. Closes ticket 14128. Useful for controllers to
          get recent bandwidth history after the fix for ticket 13988.
        - Messages about problems in the bootstrap process now include
          information about the server we were trying to connect to when we
          noticed the problem. Closes ticket 15006.
    
      o Minor features (Denial of service resistance):
        - Count the total number of bytes used storing hidden service
          descriptors against the value of MaxMemInQueues. If we're low on
          memory, and more than 20% of our memory is used holding hidden
          service descriptors, free them until no more than 10% of our
          memory holds hidden service descriptors. Free the least recently
          fetched descriptors first. Resolves ticket 13806.
        - When we have recently been under memory pressure (over 3/4 of
          MaxMemInQueues is allocated), then allocate smaller zlib objects
          for small requests. Closes ticket 11791.
    
      o Minor features (directory authorities):
        - Don't list relays with a bandwidth estimate of 0 in the consensus.
          Implements a feature proposed during discussion of bug 13000.
        - In tor-gencert, report an error if the user provides the same
          argument more than once.
        - If a directory authority can't find a best consensus method in the
          votes that it holds, it now falls back to its favorite consensus
          method. Previously, it fell back to method 1. Neither of these is
          likely to get enough signatures, but "fall back to favorite"
          doesn't require us to maintain support an obsolete consensus
          method. Implements part of proposal 215.
    
      o Minor features (geoip):
        - Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
        - Update geoip6 to the March 3 2015 Maxmind GeoLite2
          Country database.
    
      o Minor features (guard nodes):
        - Reduce the time delay before saving guard status to disk from 10
          minutes to 30 seconds (or from one hour to 10 minutes if
          AvoidDiskWrites is set). Closes ticket 12485.
    
      o Minor features (heartbeat):
        - On relays, report how many connections we negotiated using each
          version of the Tor link protocols. This information will let us
          know if removing support for very old versions of the Tor
          protocols is harming the network. Closes ticket 15212.
    
      o Minor features (hidden service):
        - Make Sybil attacks against hidden services harder by changing the
          minimum time required to get the HSDir flag from 25 hours up to 96
          hours. Addresses ticket 14149.
        - New option "HiddenServiceAllowUnknownPorts" to allow hidden
          services to disable the anti-scanning feature introduced in
          0.2.6.2-alpha. With this option not set, a connection to an
          unlisted port closes the circuit. With this option set, only a
          RELAY_DONE cell is sent. Closes ticket 14084.
        - When re-enabling the network, don't try to build introduction
          circuits until we have successfully built a circuit. This makes
          hidden services come up faster when the network is re-enabled.
          Patch from "akwizgran". Closes ticket 13447.
        - When we fail to retrieve a hidden service descriptor, send the
          controller an "HS_DESC FAILED" controller event. Implements
          feature 13212.
        - New HiddenServiceDirGroupReadable option to cause hidden service
          directories and hostname files to be created group-readable. Patch
          from "anon", David Stainton, and "meejah". Closes ticket 11291.
    
      o Minor features (interface):
        - Implement "-f -" command-line option to read torrc configuration
          from standard input, if you don't want to store the torrc file in
          the file system. Implements feature 13865.
    
      o Minor features (logging):
        - Add a count of unique clients to the bridge heartbeat message.
          Resolves ticket 6852.
        - Suppress "router info incompatible with extra info" message when
          reading extrainfo documents from cache. (This message got loud
          around when we closed bug 9812 in 0.2.6.2-alpha.) Closes
          ticket 13762.
        - Elevate hidden service authorized-client message from DEBUG to
          INFO. Closes ticket 14015.
        - On Unix-like systems, you can now use named pipes as the target of
          the Log option, and other options that try to append to files.
          Closes ticket 12061. Patch from "carlo von lynX".
        - When opening a log file at startup, send it every log message that
          we generated between startup and opening it. Previously, log
          messages that were generated before opening the log file were only
          logged to stdout. Closes ticket 6938.
        - Add a TruncateLogFile option to overwrite logs instead of
          appending to them. Closes ticket 5583.
        - Quiet some log messages in the heartbeat and at startup. Closes
          ticket 14950.
    
      o Minor features (portability, Solaris):
        - Threads are no longer disabled by default on Solaris; we believe
          that the versions of Solaris with broken threading support are all
          obsolete by now. Resolves ticket 9495.
    
      o Minor features (relay):
        - Re-check our address after we detect a changed IP address from
          getsockname(). This ensures that the controller command "GETINFO
          address" will report the correct value. Resolves ticket 11582.
          Patch from "ra".
        - A new AccountingRule option lets Relays set whether they'd like
          AccountingMax to be applied separately to inbound and outbound
          traffic, or applied to the sum of inbound and outbound traffic.
          Resolves ticket 961. Patch by "chobe".
        - When identity keypair is generated for first time, log a
          congratulatory message that links to the new relay lifecycle
          document. Implements feature 10427.
    
      o Minor features (security, memory wiping):
        - Ensure we securely wipe keys from memory after
          crypto_digest_get_digest and init_curve25519_keypair_from_file
          have finished using them. Resolves ticket 13477.
    
      o Minor features (security, out-of-memory handling):
        - When handling an out-of-memory condition, allocate less memory for
          temporary data structures. Fixes issue 10115.
        - When handling an out-of-memory condition, consider more types of
          buffers, including those on directory connections, and zlib
          buffers. Resolves ticket 11792.
    
      o Minor features (stability):
        - Add assertions in our hash-table iteration code to check for
          corrupted values that could cause infinite loops. Closes
          ticket 11737.
    
      o Minor features (systemd):
        - Various improvements and modernizations in systemd hardening
          support. Closes ticket 13805. Patch from Craig Andrews.
        - Where supported, when running with systemd, report successful
          startup to systemd. Part of ticket 11016. Patch by Michael Scherer.
        - When running with systemd, support systemd watchdog messages. Part
          of ticket 11016. Patch by Michael Scherer.
    
      o Minor features (testing networks):
        - Add the TestingDirAuthVoteExit option, which lists nodes to assign
          the "Exit" flag regardless of their uptime, bandwidth, or exit
          policy. TestingTorNetwork must be set for this option to have any
          effect. Previously, authorities would take up to 35 minutes to
          give nodes the Exit flag in a test network. Partially implements
          ticket 13161.
        - Drop the minimum RendPostPeriod on a testing network to 5 seconds,
          and the default on a testing network to 2 minutes. Drop the
          MIN_REND_INITIAL_POST_DELAY on a testing network to 5 seconds, but
          keep the default on a testing network at 30 seconds. This reduces
          HS bootstrap time to around 25 seconds. Also, change the default
          time in test-network.sh to match. Closes ticket 13401. Patch
          by "teor".
        - Create TestingDirAuthVoteHSDir to correspond to
          TestingDirAuthVoteExit/Guard. Ensures that authorities vote the
          HSDir flag for the listed relays regardless of uptime or ORPort
          connectivity. Respects the value of VoteOnHidServDirectoriesV2.
          Partial implementation for ticket 14067. Patch by "teor".
    
      o Minor features (tor2web mode):
        - Introduce the config option Tor2webRendezvousPoints, which allows
          clients in Tor2webMode to select a specific Rendezvous Point to be
          used in HS circuits. This might allow better performance for
          Tor2Web nodes. Implements ticket 12844.
    
      o Minor features (transparent proxy):
        - Update the transparent proxy option checks to allow for both ipfw
          and pf on OS X. Closes ticket 14002.
        - Use the correct option when using IPv6 with transparent proxy
          support on Linux. Resolves 13808. Patch by Francisco Blas
          Izquierdo Riera.
    
      o Minor features (validation):
        - Check all date/time values passed to tor_timegm and
          parse_rfc1123_time for validity, taking leap years into account.
          Improves HTTP header validation. Implemented with bug 13476.
        - In correct_tm(), limit the range of values returned by system
          localtime(_r) and gmtime(_r) to be between the years 1 and 8099.
          This means we don't have to deal with negative or too large dates,
          even if a clock is wrong. Otherwise we might fail to read a file
          written by us which includes such a date. Fixes bug 13476.
        - Stop allowing invalid address patterns like "*/24" that contain
          both a wildcard address and a bit prefix length. This affects all
          our address-range parsing code. Fixes bug 7484; bugfix
          on 0.0.2pre14.
    
      o Minor bugfixes (bridge clients):
        - When configured to use a bridge without an identity digest (not
          recommended), avoid launching an extra channel to it when
          bootstrapping. Fixes bug 7733; bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (bridges):
        - When DisableNetwork is set, do not launch pluggable transport
          plugins, and if any are running, terminate them. Fixes bug 13213;
          bugfix on 0.2.3.6-alpha.
    
      o Minor bugfixes (C correctness):
        - Fix several instances of possible integer overflow/underflow/NaN.
          Fixes bug 13104; bugfix on 0.2.3.1-alpha and later. Patches
          from "teor".
        - In circuit_build_times_calculate_timeout() in circuitstats.c,
          avoid dividing by zero in the pareto calculations. This traps
          under clang's "undefined-trap" sanitizer. Fixes bug 13290; bugfix
          on 0.2.2.2-alpha.
        - Fix an integer overflow in format_time_interval(). Fixes bug
          13393; bugfix on 0.2.0.10-alpha.
        - Set the correct day of year value when the system's localtime(_r)
          or gmtime(_r) functions fail to set struct tm. Not externally
          visible. Fixes bug 13476; bugfix on 0.0.2pre14.
        - Avoid unlikely signed integer overflow in tor_timegm on systems
          with 32-bit time_t. Fixes bug 13476; bugfix on 0.0.2pre14.
    
      o Minor bugfixes (certificate handling):
        - If an authority operator accidentally makes a signing certificate
          with a future publication time, do not discard its real signing
          certificates. Fixes bug 11457; bugfix on 0.2.0.3-alpha.
        - Remove any old authority certificates that have been superseded
          for at least two days. Previously, we would keep superseded
          certificates until they expired, if they were published close in
          time to the certificate that superseded them. Fixes bug 11454;
          bugfix on 0.2.1.8-alpha.
    
      o Minor bugfixes (client):
        - Fix smartlist_choose_node_by_bandwidth() so that relays with the
          BadExit flag are not considered worthy candidates. Fixes bug
          13066; bugfix on 0.1.2.3-alpha.
        - Use the consensus schedule for downloading consensuses, and not
          the generic schedule. Fixes bug 11679; bugfix on 0.2.2.6-alpha.
        - Handle unsupported or malformed SOCKS5 requests properly by
          responding with the appropriate error message before closing the
          connection. Fixes bugs 12971 and 13314; bugfix on 0.0.2pre13.
    
      o Minor bugfixes (client, automapping):
        - Avoid crashing on torrc lines for VirtualAddrNetworkIPv[4|6] when
          no value follows the option. Fixes bug 14142; bugfix on
          0.2.4.7-alpha. Patch by "teor".
        - Fix a memory leak when using AutomapHostsOnResolve. Fixes bug
          14195; bugfix on 0.1.0.1-rc.
        - Prevent changes to other options from removing the wildcard value
          "." from "AutomapHostsSuffixes". Fixes bug 12509; bugfix
          on 0.2.0.1-alpha.
        - Allow MapAddress and AutomapHostsOnResolve to work together when
          an address is mapped into another address type (like .onion) that
          must be automapped at resolve time. Fixes bug 7555; bugfix
          on 0.2.0.1-alpha.
    
      o Minor bugfixes (client, bridges):
        - When we are using bridges and we had a network connectivity
          problem, only retry connecting to our currently configured
          bridges, not all bridges we know about and remember using. Fixes
          bug 14216; bugfix on 0.2.2.17-alpha.
    
      o Minor bugfixes (client, DNS):
        - Report the correct cached DNS expiration times on SOCKS port or in
          DNS replies. Previously, we would report everything as "never
          expires." Fixes bug 14193; bugfix on 0.2.3.17-beta.
        - Avoid a small memory leak when we find a cached answer for a
          reverse DNS lookup in a client-side DNS cache. (Remember, client-
          side DNS caching is off by default, and is not recommended.) Fixes
          bug 14259; bugfix on 0.2.0.1-alpha.
    
      o Minor bugfixes (client, IPv6):
        - Reject socks requests to literal IPv6 addresses when IPv6Traffic
          flag is not set; and not because the NoIPv4Traffic flag was set.
          Previously we'd looked at the NoIPv4Traffic flag for both types of
          literal addresses. Fixes bug 14280; bugfix on 0.2.4.7-alpha.
    
      o Minor bugfixes (client, microdescriptors):
        - Use a full 256 bits of the SHA256 digest of a microdescriptor when
          computing which microdescriptors to download. This keeps us from
          erroneous download behavior if two microdescriptor digests ever
          have the same first 160 bits. Fixes part of bug 13399; bugfix
          on 0.2.3.1-alpha.
        - Reset a router's status if its microdescriptor digest changes,
          even if the first 160 bits remain the same. Fixes part of bug
          13399; bugfix on 0.2.3.1-alpha.
    
      o Minor bugfixes (client, torrc):
        - Stop modifying the value of our DirReqStatistics torrc option just
          because we're not a bridge or relay. This bug was causing Tor
          Browser users to write "DirReqStatistics 0" in their torrc files
          as if they had chosen to change the config. Fixes bug 4244; bugfix
          on 0.2.3.1-alpha.
        - When GeoIPExcludeUnknown is enabled, do not incorrectly decide
          that our options have changed every time we SIGHUP. Fixes bug
          9801; bugfix on 0.2.4.10-alpha. Patch from "qwerty1".
    
      o Minor bugfixes (compilation):
        - Fix a compilation warning on s390. Fixes bug 14988; bugfix
          on 0.2.5.2-alpha.
        - Silence clang warnings under --enable-expensive-hardening,
          including implicit truncation of 64 bit values to 32 bit, const
          char assignment to self, tautological compare, and additional
          parentheses around equality tests. Fixes bug 13577; bugfix
          on 0.2.5.4-alpha.
        - Fix a clang warning about checking whether an address in the
          middle of a structure is NULL. Fixes bug 14001; bugfix
          on 0.2.1.2-alpha.
        - The address of an array in the middle of a structure will always
          be non-NULL. clang recognises this and complains. Disable the
          tautologous and redundant check to silence this warning. Fixes bug
          14001; bugfix on 0.2.1.2-alpha.
        - Compile correctly with (unreleased) OpenSSL 1.1.0 headers.
          Addresses ticket 14188.
        - Build without warnings with the stock OpenSSL srtp.h header, which
          has a duplicate declaration of SSL_get_selected_srtp_profile().
          Fixes bug 14220; this is OpenSSL's bug, not ours.
        - Do not compile any code related to Tor2Web mode when Tor2Web mode
          is not enabled at compile time. Previously, this code was included
          in a disabled state. See discussion on ticket 12844.
        - Allow our configure script to build correctly with autoconf 2.62
          again. Fixes bug 12693; bugfix on 0.2.5.2-alpha.
        - Improve the error message from ./configure to make it clear that
          when asciidoc has not been found, the user will have to either add
          --disable-asciidoc argument or install asciidoc. Resolves
          ticket 13228.
    
      o Minor bugfixes (controller):
        - Report "down" in response to the "GETINFO entry-guards" command
          when relays are down with an unreachable_since value. Previously,
          we would report "up". Fixes bug 14184; bugfix on 0.1.2.2-alpha.
        - Avoid crashing on a malformed EXTENDCIRCUIT command. Fixes bug
          14116; bugfix on 0.2.2.9-alpha.
    
      o Minor bugfixes (controller):
        - Return an error when the second or later arguments of the
          "setevents" controller command are invalid events. Previously we
          would return success while silently skipping invalid events. Fixes
          bug 13205; bugfix on 0.2.3.2-alpha. Reported by "fpxnns".
    
      o Minor bugfixes (directory authority):
        - Allow directory authorities to fetch more data from one another if
          they find themselves missing lots of votes. Previously, they had
          been bumping against the 10 MB queued data limit. Fixes bug 14261;
          bugfix on 0.1.2.5-alpha.
        - Do not attempt to download extrainfo documents which we will be
          unable to validate with a matching server descriptor. Fixes bug
          13762; bugfix on 0.2.0.1-alpha.
        - Fix a bug that was truncating AUTHDIR_NEWDESC events sent to the
          control port. Fixes bug 14953; bugfix on 0.2.0.1-alpha.
        - Enlarge the buffer to read bwauth generated files to avoid an
          issue when parsing the file in dirserv_read_measured_bandwidths().
          Fixes bug 14125; bugfix on 0.2.2.1-alpha.
        - When running as a v3 directory authority, advertise that you serve
          extra-info documents so that clients who want them can find them
          from you too. Fixes part of bug 11683; bugfix on 0.2.0.1-alpha.
    
      o Minor bugfixes (directory system):
        - Always believe that v3 directory authorities serve extra-info
          documents, whether they advertise "caches-extra-info" or not.
          Fixes part of bug 11683; bugfix on 0.2.0.1-alpha.
        - Check the BRIDGE_DIRINFO flag bitwise rather than using equality.
          Previously, directories offering BRIDGE_DIRINFO and some other
          flag (i.e. microdescriptors or extrainfo) would be ignored when
          looking for bridges. Partially fixes bug 13163; bugfix
          on 0.2.0.7-alpha.
    
      o Minor bugfixes (file handling):
        - Stop failing when key files are zero-length. Instead, generate new
          keys, and overwrite the empty key files. Fixes bug 13111; bugfix
          on all versions of Tor. Patch by "teor".
        - Stop generating a fresh .old RSA onion key file when the .old file
          is missing. Fixes part of 13111; bugfix on 0.0.6rc1.
        - Avoid overwriting .old key files with empty key files.
        - Skip loading zero-length extrainfo store, router store, stats,
          state, and key files.
        - Avoid crashing when trying to reload a torrc specified as a
          relative path with RunAsDaemon turned on. Fixes bug 13397; bugfix
          on 0.2.3.11-alpha.
    
      o Minor bugfixes (hidden services):
        - Close the introduction circuit when we have no more usable intro
          points, instead of waiting for it to time out. This also ensures
          that no follow-up HS descriptor fetch is triggered when the
          circuit eventually times out. Fixes bug 14224; bugfix on 0.0.6.
        - When fetching a hidden service descriptor for a down service that
          was recently up, do not keep refetching until we try the same
          replica twice in a row. Fixes bug 14219; bugfix on 0.2.0.10-alpha.
        - Correctly send a controller event when we find that a rendezvous
          circuit has finished. Fixes bug 13936; bugfix on 0.1.1.5-alpha.
        - Pre-check directory permissions for new hidden-services to avoid
          at least one case of "Bug: Acting on config options left us in a
          broken state. Dying." Fixes bug 13942; bugfix on 0.0.6pre1.
        - When fetching hidden service descriptors, we now check not only
          for whether we got the hidden service we had in mind, but also
          whether we got the particular descriptors we wanted. This prevents
          a class of inefficient but annoying DoS attacks by hidden service
          directories. Fixes bug 13214; bugfix on 0.2.1.6-alpha. Reported
          by "special".
    
      o Minor bugfixes (Linux seccomp2 sandbox):
        - Make transparent proxy support work along with the seccomp2
          sandbox. Fixes part of bug 13808; bugfix on 0.2.5.1-alpha. Patch
          by Francisco Blas Izquierdo Riera.
        - Fix a memory leak in tor-resolve when running with the sandbox
          enabled. Fixes bug 14050; bugfix on 0.2.5.9-rc.
        - Allow glibc fatal errors to be sent to stderr before Tor exits.
          Previously, glibc would try to write them to /dev/tty, and the
          sandbox would trap the call and make Tor exit prematurely. Fixes
          bug 14759; bugfix on 0.2.5.1-alpha.
    
      o Minor bugfixes (logging):
        - Avoid crashing when there are more log domains than entries in
          domain_list. Bugfix on 0.2.3.1-alpha.
        - Downgrade warnings about RSA signature failures to info log level.
          Emit a warning when an extra info document is found incompatible
          with a corresponding router descriptor. Fixes bug 9812; bugfix
          on 0.0.6rc3.
        - Make connection_ap_handshake_attach_circuit() log the circuit ID
          correctly. Fixes bug 13701; bugfix on 0.0.6.
    
      o Minor bugfixes (networking):
        - Check for orconns and use connection_or_close_for_error() rather
          than connection_mark_for_close() directly in the getsockopt()
          failure case of connection_handle_write_impl(). Fixes bug 11302;
          bugfix on 0.2.4.4-alpha.
    
      o Minor bugfixes (parsing):
        - Stop accepting milliseconds (or other junk) at the end of
          descriptor publication times. Fixes bug 9286; bugfix on 0.0.2pre25.
        - Support two-number and three-number version numbers correctly, in
          case we change the Tor versioning system in the future. Fixes bug
          13661; bugfix on 0.0.8pre1.
    
      o Minor bugfixes (portability):
        - Fix the ioctl()-based network interface lookup code so that it
          will work on systems that have variable-length struct ifreq, for
          example Mac OS X.
        - Use the correct datatype in the SipHash-2-4 function to prevent
          compilers from assuming any sort of alignment. Fixes bug 15436;
          bugfix on 0.2.5.3-alpha.
    
      o Minor bugfixes (preventative security, C safety):
        - When reading a hexadecimal, base-32, or base-64 encoded value from
          a string, always overwrite the whole output buffer. This prevents
          some bugs where we would look at (but fortunately, not reveal)
          uninitialized memory on the stack. Fixes bug 14013; bugfix on all
          versions of Tor.
        - Clear all memory targeted by tor_addr_{to,from}_sockaddr(), not
          just the part that's used. This makes it harder for data leak bugs
          to occur in the event of other programming failures. Resolves
          ticket 14041.
    
      o Minor bugfixes (relay):
        - When generating our family list, remove spaces from around the
          entries. Fixes bug 12728; bugfix on 0.2.1.7-alpha.
        - If our previous bandwidth estimate was 0 bytes, allow publishing a
          new relay descriptor immediately. Fixes bug 13000; bugfix
          on 0.1.1.6-alpha.
    
      o Minor bugfixes (shutdown):
        - When shutting down, always call event_del() on lingering read or
          write events before freeing them. Otherwise, we risk double-frees
          or read-after-frees in event_base_free(). Fixes bug 12985; bugfix
          on 0.1.0.2-rc.
    
      o Minor bugfixes (small memory leaks):
        - Avoid leaking memory when using IPv6 virtual address mappings.
          Fixes bug 14123; bugfix on 0.2.4.7-alpha. Patch by Tom van
          der Woerdt.
    
      o Minor bugfixes (statistics):
        - Increase period over which bandwidth observations are aggregated
          from 15 minutes to 4 hours. Fixes bug 13988; bugfix on 0.0.8pre1.
    
      o Minor bugfixes (systemd support):
        - Run correctly under systemd with the RunAsDaemon option set. Fixes
          part of bug 14141; bugfix on 0.2.5.7-rc. Patch from Tomasz Torcz.
        - Inform the systemd supervisor about more changes in the Tor
          process status. Implements part of ticket 14141. Patch from
          Tomasz Torcz.
    
      o Minor bugfixes (testing networks):
        - Fix TestingDirAuthVoteGuard to properly give out Guard flags in a
          testing network. Fixes bug 13064; bugfix on 0.2.5.2-alpha.
        - Stop using the default authorities in networks which provide both
          AlternateDirAuthority and AlternateBridgeAuthority. Partially
          fixes bug 13163; bugfix on 0.2.0.13-alpha.
    
      o Minor bugfixes (testing networks, fast startup):
        - Allow Tor to build circuits using a consensus with no exits. If
          the consensus has no exits (typical of a bootstrapping test
          network), allow Tor to build circuits once enough descriptors have
          been downloaded. This assists in bootstrapping a testing Tor
          network. Fixes bug 13718; bugfix on 0.2.4.10-alpha. Patch
          by "teor".
        - When V3AuthVotingInterval is low, give a lower If-Modified-Since
          header to directory servers. This allows us to obtain consensuses
          promptly when the consensus interval is very short. This assists
          in bootstrapping a testing Tor network. Fixes parts of bugs 13718
          and 13963; bugfix on 0.2.0.3-alpha. Patch by "teor".
        - Stop assuming that private addresses are local when checking
          reachability in a TestingTorNetwork. Instead, when testing, assume
          all OR connections are remote. (This is necessary due to many test
          scenarios running all relays on localhost.) This assists in
          bootstrapping a testing Tor network. Fixes bug 13924; bugfix on
          0.1.0.1-rc. Patch by "teor".
        - Avoid building exit circuits from a consensus with no exits. Now
          thanks to our fix for 13718, we accept a no-exit network as not
          wholly lost, but we need to remember not to try to build exit
          circuits on it. Closes ticket 13814; patch by "teor".
        - Stop requiring exits to have non-zero bandwithcapacity in a
          TestingTorNetwork. Instead, when TestingMinExitFlagThreshold is 0,
          ignore exit bandwidthcapacity. This assists in bootstrapping a
          testing Tor network. Fixes parts of bugs 13718 and 13839; bugfix
          on 0.2.0.3-alpha. Patch by "teor".
        - Add "internal" to some bootstrap statuses when no exits are
          available. If the consensus does not contain Exits, Tor will only
          build internal circuits. In this case, relevant statuses will
          contain the word "internal" as indicated in the Tor control-
           spec.txt. When bootstrap completes, Tor will be ready to build
          internal circuits. If a future consensus contains Exits, exit
          circuits may become available. Fixes part of bug 13718; bugfix on
          0.2.4.10-alpha. Patch by "teor".
        - Decrease minimum consensus interval to 10 seconds when
          TestingTorNetwork is set, or 5 seconds for the first consensus.
          Fix assumptions throughout the code that assume larger intervals.
          Fixes bugs 13718 and 13823; bugfix on 0.2.0.3-alpha. Patch
          by "teor".
        - Avoid excluding guards from path building in minimal test
          networks, when we're in a test network and excluding guards would
          exclude all relays. This typically occurs in incredibly small tor
          networks, and those using "TestingAuthVoteGuard *". Fixes part of
          bug 13718; bugfix on 0.1.1.11-alpha. Patch by "teor".
    
      o Minor bugfixes (testing):
        - Avoid a side-effect in a tor_assert() in the unit tests. Fixes bug
          15188; bugfix on 0.1.2.3-alpha. Patch from Tom van der Woerdt.
        - Stop spawn test failures due to a race condition between the
          SIGCHLD handler updating the process status, and the test reading
          it. Fixes bug 13291; bugfix on 0.2.3.3-alpha.
        - Avoid passing an extra backslash when creating a temporary
          directory for running the unit tests on Windows. Fixes bug 12392;
          bugfix on 0.2.2.25-alpha. Patch from Gisle Vanem.
    
      o Minor bugfixes (TLS):
        - Check more thoroughly throughout the TLS code for possible
          unlogged TLS errors. Possible diagnostic or fix for bug 13319.
    
      o Minor bugfixes (transparent proxy):
        - Use getsockname, not getsockopt, to retrieve the address for a
          TPROXY-redirected connection. Fixes bug 13796; bugfix
          on 0.2.5.2-alpha.
    
      o Minor bugfixes (windows):
        - Remove code to special-case handling of NTE_BAD_KEYSET when
          acquiring windows CryptoAPI context. This error can't actually
          occur for the parameters we're providing. Fixes bug 10816; bugfix
          on 0.0.2pre26.
    
      o Minor bugfixes (zlib):
        - Avoid truncating a zlib stream when trying to finalize it with an
          empty output buffer. Fixes bug 11824; bugfix on 0.1.1.23.
    
      o Code simplification and refactoring:
        - Change the entry_is_live() function to take named bitfield
          elements instead of an unnamed list of booleans. Closes
          ticket 12202.
        - Refactor and unit-test entry_is_time_to_retry() in entrynodes.c.
          Resolves ticket 12205.
        - Use calloc and reallocarray functions instead of multiply-
          then-malloc. This makes it less likely for us to fall victim to an
          integer overflow attack when allocating. Resolves ticket 12855.
        - Use the standard macro name SIZE_MAX, instead of our
          own SIZE_T_MAX.
        - Document usage of the NO_DIRINFO and ALL_DIRINFO flags clearly in
          functions which take them as arguments. Replace 0 with NO_DIRINFO
          in a function call for clarity. Seeks to prevent future issues
          like 13163.
        - Avoid 4 null pointer errors under clang static analysis by using
          tor_assert() to prove that the pointers aren't null. Fixes
          bug 13284.
        - Rework the API of policies_parse_exit_policy() to use a bitmask to
          represent parsing options, instead of a confusing mess of
          booleans. Resolves ticket 8197.
        - Introduce a helper function to parse ExitPolicy in
          or_options_t structure.
        - Move fields related to isolating and configuring client ports into
          a shared structure. Previously, they were duplicated across
          port_cfg_t, listener_connection_t, and edge_connection_t. Failure
          to copy them correctly had been the cause of at least one bug in
          the past. Closes ticket 8546.
        - Refactor the get_interface_addresses_raw() doom-function into
          multiple smaller and simpler subfunctions. Cover the resulting
          subfunctions with unit-tests. Fixes a significant portion of
          issue 12376.
        - Remove workaround in dirserv_thinks_router_is_hs_dir() that was
          only for version <= 0.2.2.24 which is now deprecated. Closes
          ticket 14202.
        - Remove a test for a long-defunct broken version-one
          directory server.
        - Refactor main loop to extract the 'loop' part. This makes it
          easier to run Tor under Shadow. Closes ticket 15176.
        - Stop using can_complete_circuits as a global variable; access it
          with a function instead.
        - Avoid using operators directly as macro arguments: this lets us
          apply coccinelle transformations to our codebase more directly.
          Closes ticket 13172.
        - Combine the functions used to parse ClientTransportPlugin and
          ServerTransportPlugin into a single function. Closes ticket 6456.
        - Add inline functions and convenience macros for inspecting channel
          state. Refactor the code to use convenience macros instead of
          checking channel state directly. Fixes issue 7356.
        - Document all members of was_router_added_t and rename
          ROUTER_WAS_NOT_NEW to ROUTER_IS_ALREADY_KNOWN to make it less
          confusable with ROUTER_WAS_TOO_OLD. Fixes issue 13644.
        - In connection_exit_begin_conn(), use END_CIRC_REASON_TORPROTOCOL
          constant instead of hardcoded value. Fixes issue 13840.
        - Refactor our generic strmap and digestmap types into a single
          implementation, so that we can add a new digest256map
          type trivially.
    
      o Documentation:
        - Add a doc/TUNING document with tips for handling large numbers of
          TCP connections when running busy Tor relay. Update the warning
          message to point to this file when running out of sockets
          operating system is allowing to use simultaneously. Resolves
          ticket 9708.
        - Adding section on OpenBSD to our TUNING document. Thanks to mmcc
          for writing the OpenBSD-specific tips. Resolves ticket 13702.
        - Make the tor-resolve documentation match its help string and its
          options. Resolves part of ticket 14325.
        - Log a more useful error message from tor-resolve when failing to
          look up a hidden service address. Resolves part of ticket 14325.
        - Document the bridge-authority-only 'networkstatus-bridges' file.
          Closes ticket 13713; patch from "tom".
        - Fix typo in PredictedPortsRelevanceTime option description in
          manpage. Resolves issue 13707.
        - Stop suggesting that users specify relays by nickname: it isn't a
          good idea. Also, properly cross-reference how to specify relays in
          all parts of manual documenting options that take a list of
          relays. Closes ticket 13381.
        - Clarify the HiddenServiceDir option description in manpage to make
          it clear that relative paths are taken with respect to the current
          working directory. Also clarify that this behavior is not
          guaranteed to remain indefinitely. Fixes issue 13913.
    
      o Distribution (systemd):
        - systemd unit file: only allow tor to write to /var/lib/tor and
          /var/log/tor. The rest of the filesystem is accessible for reading
          only. Patch by intrigeri; resolves ticket 12751.
        - systemd unit file: ensure that the process and all its children
          can never gain new privileges. Patch by intrigeri; resolves
          ticket 12939.
        - systemd unit file: set up /var/run/tor as writable for the Tor
          service. Patch by intrigeri; resolves ticket 13196.
    
      o Downgraded warnings:
        - Don't warn when we've attempted to contact a relay using the wrong
          ntor onion key. Closes ticket 9635.
    
      o Removed code:
        - Remove some lingering dead code that once supported mempools.
          Mempools were disabled by default in 0.2.5, and removed entirely
          in 0.2.6.3-alpha. Closes more of ticket 14848; patch
          by "cypherpunks".
    
      o Removed features (directory authorities):
        - Remove code that prevented authorities from listing Tor relays
          affected by CVE-2011-2769 as guards. These relays are already
          rejected altogether due to the minimum version requirement of
          0.2.3.16-alpha. Closes ticket 13152.
        - The "AuthDirRejectUnlisted" option no longer has any effect, as
          the fingerprints file (approved-routers) has been deprecated.
        - Directory authorities do not support being Naming dirauths anymore.
          The "NamingAuthoritativeDir" config option is now obsolete.
        - Directory authorities do not support giving out the BadDirectory
          flag anymore.
        - Directory authorities no longer advertise or support consensus
          methods 1 through 12 inclusive. These consensus methods were
          obsolete and/or insecure: maintaining the ability to support them
          served no good purpose. Implements part of proposal 215; closes
          ticket 10163.
    
      o Removed features:
        - To avoid confusion with the "ExitRelay" option, "ExitNode" is no
          longer silently accepted as an alias for "ExitNodes".
        - The --enable-mempool and --enable-buf-freelists options, which
          were originally created to work around bad malloc implementations,
          no longer exist. They were off-by-default in 0.2.5. Closes
          ticket 14848.
        - We no longer remind the user about configuration options that have
          been obsolete since 0.2.3.x or earlier. Patch by Adrien Bak.
        - Remove our old, non-weighted bandwidth-based node selection code.
          Previously, we used it as a fallback when we couldn't perform
          weighted bandwidth-based node selection. But that would only
          happen in the cases where we had no consensus, or when we had a
          consensus generated by buggy or ancient directory authorities. In
          either case, it's better to use the more modern, better maintained
          algorithm, with reasonable defaults for the weights. Closes
          ticket 13126.
        - Remove the --disable-curve25519 configure option. Relays and
          clients now are required to support curve25519 and the
          ntor handshake.
        - The old "StrictEntryNodes" and "StrictExitNodes" options, which
          used to be deprecated synonyms for "StrictNodes", are now marked
          obsolete. Resolves ticket 12226.
        - Clients don't understand the BadDirectory flag in the consensus
          anymore, and ignore it.
    
      o Removed platform support:
        - We no longer include special code to build on Windows CE; as far
          as we know, nobody has used Tor on Windows CE in a very long time.
          Closes ticket 11446.
    
      o Testing (test-network.sh):
        - Stop using "echo -n", as some shells' built-in echo doesn't
          support "-n". Instead, use "/bin/echo -n". Partially fixes
          bug 13161.
        - Stop an apparent test-network hang when used with make -j2. Fixes
          bug 13331.
        - Add a --delay option to test-network.sh, which configures the
          delay before the chutney network tests for data transmission.
          Partially implements ticket 13161.
    
      o Testing:
        - Test that tor does not fail when key files are zero-length. Check
          that tor generates new keys, and overwrites the empty key files.
        - Test that tor generates new keys when keys are missing
          (existing behavior).
        - Test that tor does not overwrite key files that already contain
          data (existing behavior). Tests bug 13111. Patch by "teor".
        - New "make test-stem" target to run stem integration tests.
          Requires that the "STEM_SOURCE_DIR" environment variable be set.
          Closes ticket 14107.
        - Make the test_cmdline_args.py script work correctly on Windows.
          Patch from Gisle Vanem.
        - Move the slower unit tests into a new "./src/test/test-slow"
          binary that can be run independently of the other tests. Closes
          ticket 13243.
        - New tests for many parts of channel, relay, and circuitmux
          functionality. Code by Andrea; part of 9262.
        - New tests for parse_transport_line(). Part of ticket 6456.
        - In the unit tests, use chgrp() to change the group of the unit
          test temporary directory to the current user, so that the sticky
          bit doesn't interfere with tests that check directory groups.
          Closes 13678.
        - Add unit tests for resolve_my_addr(). Part of ticket 12376; patch
          by 'rl1987'.
        - Refactor the function that chooses guard nodes so that it can more
          easily be tested; write some tests for it.
        - Fix and re-enable the fgets_eagain unit test. Fixes bug 12503;
          bugfix on 0.2.3.1-alpha. Patch from "cypherpunks."
        - Create unit tests for format_time_interval(). With bug 13393.
        - Add unit tests for tor_timegm signed overflow, tor_timegm and
          parse_rfc1123_time validity checks, correct_tm year clamping. Unit
          tests (visible) fixes in bug 13476.
        - Add a "coverage-html" make target to generate HTML-visualized
          coverage results when building with --enable-coverage. (Requires
          lcov.) Patch from Kevin Murray.
        - Enable the backtrace handler (where supported) when running the
          unit tests.
        - Revise all unit tests that used the legacy test_* macros to
          instead use the recommended tt_* macros. This patch was generated
          with coccinelle, to avoid manual errors. Closes ticket 13119.
    
    Changes in version 0.2.5.11 - 2015-03-17
      Tor 0.2.5.11 is the second stable release in the 0.2.5 series.
    
      It backports several bugfixes from the 0.2.6 branch, including a
      couple of medium-level security fixes for relays and exit nodes.
      It also updates the list of directory authorities.
    
      o Directory authority changes:
        - Remove turtles as a directory authority.
        - Add longclaw as a new (v3) directory authority. This implements
          ticket 13296. This keeps the directory authority count at 9.
        - The directory authority Faravahar has a new IP address. This
          closes ticket 14487.
    
      o Major bugfixes (crash, OSX, security):
        - Fix a remote denial-of-service opportunity caused by a bug in
          OSX's _strlcat_chk() function. Fixes bug 15205; bug first appeared
          in OSX 10.9.
    
      o Major bugfixes (relay, stability, possible security):
        - Fix a bug that could lead to a relay crashing with an assertion
          failure if a buffer of exactly the wrong layout was passed to
          buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on
          0.2.0.10-alpha. Patch from 'cypherpunks'.
        - Do not assert if the 'data' pointer on a buffer is advanced to the
          very end of the buffer; log a BUG message instead. Only assert if
          it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.
    
      o Major bugfixes (exit node stability):
        - Fix an assertion failure that could occur under high DNS load.
          Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr";
          diagnosed and fixed by "cypherpunks".
    
      o Major bugfixes (Linux seccomp2 sandbox):
        - Upon receiving sighup with the seccomp2 sandbox enabled, do not
          crash during attempts to call wait4. Fixes bug 15088; bugfix on
          0.2.5.1-alpha. Patch from "sanic".
    
      o Minor features (controller):
        - New "GETINFO bw-event-cache" to get information about recent
          bandwidth events. Closes ticket 14128. Useful for controllers to
          get recent bandwidth history after the fix for ticket 13988.
    
      o Minor features (geoip):
        - Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
        - Update geoip6 to the March 3 2015 Maxmind GeoLite2
          Country database.
    
      o Minor bugfixes (client, automapping):
        - Avoid crashing on torrc lines for VirtualAddrNetworkIPv[4|6] when
          no value follows the option. Fixes bug 14142; bugfix on
          0.2.4.7-alpha. Patch by "teor".
        - Fix a memory leak when using AutomapHostsOnResolve. Fixes bug
          14195; bugfix on 0.1.0.1-rc.
    
      o Minor bugfixes (compilation):
        - Build without warnings with the stock OpenSSL srtp.h header, which
          has a duplicate declaration of SSL_get_selected_srtp_profile().
          Fixes bug 14220; this is OpenSSL's bug, not ours.
    
      o Minor bugfixes (directory authority):
        - Allow directory authorities to fetch more data from one another if
          they find themselves missing lots of votes. Previously, they had
          been bumping against the 10 MB queued data limit. Fixes bug 14261;
          bugfix on 0.1.2.5-alpha.
        - Enlarge the buffer to read bwauth generated files to avoid an
          issue when parsing the file in dirserv_read_measured_bandwidths().
          Fixes bug 14125; bugfix on 0.2.2.1-alpha.
    
      o Minor bugfixes (statistics):
        - Increase period over which bandwidth observations are aggregated
          from 15 minutes to 4 hours. Fixes bug 13988; bugfix on 0.0.8pre1.
    
      o Minor bugfixes (preventative security, C safety):
        - When reading a hexadecimal, base-32, or base-64 encoded value from
          a string, always overwrite the whole output buffer. This prevents
          some bugs where we would look at (but fortunately, not reveal)
          uninitialized memory on the stack. Fixes bug 14013; bugfix on all
          versions of Tor.
    
    
    Changes in version 0.2.4.26 - 2015-03-17
      Tor 0.2.4.26 includes an updated list of directory authorities.  It
      also backports a couple of stability and security bugfixes from 0.2.5
      and beyond.
    
      o Directory authority changes:
        - Remove turtles as a directory authority.
        - Add longclaw as a new (v3) directory authority. This implements
          ticket 13296. This keeps the directory authority count at 9.
        - The directory authority Faravahar has a new IP address. This
          closes ticket 14487.
    
      o Major bugfixes (exit node stability, also in 0.2.6.3-alpha):
        - Fix an assertion failure that could occur under high DNS load.
          Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr";
          diagnosed and fixed by "cypherpunks".
    
      o Major bugfixes (relay, stability, possible security, also in 0.2.6.4-rc):
        - Fix a bug that could lead to a relay crashing with an assertion
          failure if a buffer of exactly the wrong layout was passed to
          buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on
          0.2.0.10-alpha. Patch from 'cypherpunks'.
        - Do not assert if the 'data' pointer on a buffer is advanced to the
          very end of the buffer; log a BUG message instead. Only assert if
          it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.
    
      o Minor features (geoip):
        - Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
        - Update geoip6 to the March 3 2015 Maxmind GeoLite2
          Country database.
    
    Changes in version 0.2.5.10 - 2014-10-24
      Tor 0.2.5.10 is the first stable release in the 0.2.5 series.
    
      It adds several new security features, including improved
      denial-of-service resistance for relays, new compiler hardening
      options, and a system-call sandbox for hardened installations on Linux
      (requires seccomp2). The controller protocol has several new features,
      resolving IPv6 addresses should work better than before, and relays
      should be a little more CPU-efficient. We've added support for more
      OpenBSD and FreeBSD transparent proxy types. We've improved the build
      system and testing infrastructure to allow unit testing of more parts
      of the Tor codebase. Finally, we've addressed several nagging pluggable
      transport usability issues, and included numerous other small bugfixes
      and features mentioned below.
    
      This release marks end-of-life for Tor 0.2.3.x; those Tor versions
      have accumulated many known flaws; everyone should upgrade.
    
      o Major features (security):
        - The ntor handshake is now on-by-default, no matter what the
          directory authorities recommend. Implements ticket 8561.
        - Make the "tor-gencert" tool used by directory authority operators
          create 2048-bit signing keys by default (rather than 1024-bit, since
          1024-bit is uncomfortably small these days). Addresses ticket 10324.
        - Warn about attempts to run hidden services and relays in the same
          process: that's probably not a good idea. Closes ticket 12908.
        - Disable support for SSLv3. All versions of OpenSSL in use with Tor
          today support TLS 1.0 or later, so we can safely turn off support
          for this old (and insecure) protocol. Fixes bug 13426.
    
      o Major features (relay security, DoS-resistance):
        - When deciding whether we have run out of memory and we need to
          close circuits, also consider memory allocated in buffers for
          streams attached to each circuit.
    
          This change, which extends an anti-DoS feature introduced in
          0.2.4.13-alpha and improved in 0.2.4.14-alpha, lets Tor exit relays
          better resist more memory-based DoS attacks than before. Since the
          MaxMemInCellQueues option now applies to all queues, it is renamed
          to MaxMemInQueues. This feature fixes bug 10169.
        - Avoid hash-flooding denial-of-service attacks by using the secure
          SipHash-2-4 hash function for our hashtables. Without this
          feature, an attacker could degrade performance of a targeted
          client or server by flooding their data structures with a large
          number of entries to be stored at the same hash table position,
          thereby slowing down the Tor instance. With this feature, hash
          table positions are derived from a randomized cryptographic key,
          and an attacker cannot predict which entries will collide. Closes
          ticket 4900.
        - If you don't specify MaxMemInQueues yourself, Tor now tries to
          pick a good value based on your total system memory. Previously,
          the default was always 8 GB. You can still override the default by
          setting MaxMemInQueues yourself. Resolves ticket 11396.
    
      o Major features (bridges and pluggable transports):
        - Add support for passing arguments to managed pluggable transport
          proxies. Implements ticket 3594.
        - Bridges now track GeoIP information and the number of their users
          even when pluggable transports are in use, and report usage
          statistics in their extra-info descriptors. Resolves tickets 4773
          and 5040.
        - Don't launch pluggable transport proxies if we don't have any
          bridges configured that would use them. Now we can list many
          pluggable transports, and Tor will dynamically start one when it
          hears a bridge address that needs it. Resolves ticket 5018.
        - The bridge directory authority now assigns status flags (Stable,
          Guard, etc) to bridges based on thresholds calculated over all
          Running bridges. Now bridgedb can finally make use of its features
          to e.g. include at least one Stable bridge in its answers. Fixes
          bug 9859.
    
      o Major features (controller):
        - Extend ORCONN controller event to include an "ID" parameter,
          and add four new controller event types CONN_BW, CIRC_BW,
          CELL_STATS, and TB_EMPTY that show connection and circuit usage.
          The new events are emitted in private Tor networks only, with the
          goal of being able to better track performance and load during
          full-network simulations. Implements proposal 218 and ticket 7359.
    
      o Major features (relay performance):
        - Speed up server-side lookups of rendezvous and introduction point
          circuits by using hashtables instead of linear searches. These
          functions previously accounted between 3 and 7% of CPU usage on
          some busy relays. Resolves ticket 9841.
        - Avoid wasting CPU when extending a circuit over a channel that is
          nearly out of circuit IDs. Previously, we would do a linear scan
          over possible circuit IDs before finding one or deciding that we
          had exhausted our possibilities. Now, we try at most 64 random
          circuit IDs before deciding that we probably won't succeed. Fixes
          a possible root cause of ticket 11553.
    
      o Major features (seccomp2 sandbox, Linux only):
        - Use the seccomp2 syscall filtering facility on Linux to limit
          which system calls Tor can invoke. This is an experimental,
          Linux-only feature to provide defense-in-depth against unknown
          attacks. To try turning it on, set "Sandbox 1" in your torrc
          file. Please be ready to report bugs. We hope to add support
          for better sandboxing in the future, including more fine-grained
          filters, better division of responsibility, and support for more
          platforms. This work has been done by Cristian-Matei Toader for
          Google Summer of Code. Resolves tickets 11351 and 11465.
    
      o Major features (testing networks):
        - Make testing Tor networks bootstrap better: lower directory fetch
          retry schedules and maximum interval without directory requests,
          and raise maximum download tries. Implements ticket 6752.
        - Add make target 'test-network' to run tests on a Chutney network.
          Implements ticket 8530.
    
      o Major features (other):
        - On some platforms (currently: recent OSX versions, glibc-based
          platforms that support the ELF format, and a few other
          Unix-like operating systems), Tor can now dump stack traces
          when a crash occurs or an assertion fails. By default, traces
          are dumped to stderr (if possible) and to any logs that are
          reporting errors. Implements ticket 9299.
    
      o Deprecated versions:
        - Tor 0.2.3.x has reached end-of-life; it has received no patches or
          attention for some while.
    
      o Major bugfixes (security, directory authorities):
        - Directory authorities now include a digest of each relay's
          identity key as a part of its microdescriptor.
    
          This is a workaround for bug 11743 (reported by "cypherpunks"),
          where Tor clients do not support receiving multiple
          microdescriptors with the same SHA256 digest in the same
          consensus. When clients receive a consensus like this, they only
          use one of the relays. Without this fix, a hostile relay could
          selectively disable some client use of target relays by
          constructing a router descriptor with a different identity and the
          same microdescriptor parameters and getting the authorities to
          list it in a microdescriptor consensus. This fix prevents an
          attacker from causing a microdescriptor collision, because the
          router's identity is not forgeable.
    
      o Major bugfixes (openssl bug workaround):
        - Avoid crashing when using OpenSSL version 0.9.8zc, 1.0.0o, or
          1.0.1j, built with the 'no-ssl3' configuration option. Fixes
          bug 13471. This is a workaround for an OpenSSL bug.
    
      o Major bugfixes (client):
        - Perform circuit cleanup operations even when circuit
          construction operations are disabled (because the network is
          disabled, or because there isn't enough directory information).
          Previously, when we were not building predictive circuits, we
          were not closing expired circuits either. Fixes bug 8387; bugfix on
          0.1.1.11-alpha. This bug became visible in 0.2.4.10-alpha when we
          became more strict about when we have "enough directory information
          to build circuits".
    
      o Major bugfixes (client, pluggable transports):
        - When managing pluggable transports, use OS notification facilities
          to learn if they have crashed, and don't attempt to kill any
          process that has already exited. Fixes bug 8746; bugfix
          on 0.2.3.6-alpha.
    
      o Major bugfixes (relay denial of service):
        - Instead of writing destroy cells directly to outgoing connection
          buffers, queue them and intersperse them with other outgoing cells.
          This can prevent a set of resource starvation conditions where too
          many pending destroy cells prevent data cells from actually getting
          delivered. Reported by "oftc_must_be_destroyed". Fixes bug 7912;
          bugfix on 0.2.0.1-alpha.
    
      o Major bugfixes (relay):
        - Avoid queuing or sending destroy cells for circuit ID zero when we
          fail to send a CREATE cell. Fixes bug 12848; bugfix on 0.0.8pre1.
          Found and fixed by "cypherpunks".
        - Fix ORPort reachability detection on relays running behind a
          proxy, by correctly updating the "local" mark on the controlling
          channel when changing the address of an or_connection_t after the
          handshake. Fixes bug 12160; bugfix on 0.2.4.4-alpha.
        - Use a direct dirport connection when uploading non-anonymous
          descriptors to the directory authorities. Previously, relays would
          incorrectly use tunnel connections under a fairly wide variety of
          circumstances. Fixes bug 11469; bugfix on 0.2.4.3-alpha.
        - When a circuit accidentally has the same circuit ID for its
          forward and reverse direction, correctly detect the direction of
          cells using that circuit. Previously, this bug made roughly one
          circuit in a million non-functional. Fixes bug 12195; this is a
          bugfix on every version of Tor.
    
      o Minor features (security):
        - New --enable-expensive-hardening option to enable security
          hardening options that consume nontrivial amounts of CPU and
          memory. Right now, this includes AddressSanitizer and UbSan, which
          are supported in newer versions of GCC and Clang. Closes ticket
          11477.
        - Authorities now assign the Guard flag to the fastest 25% of the
          network (it used to be the fastest 50%). Also raise the consensus
          weight that guarantees the Guard flag from 250 to 2000. For the
          current network, this results in about 1100 guards, down from 2500.
          This step paves the way for moving the number of entry guards
          down to 1 (proposal 236) while still providing reasonable expected
          performance for most users. Implements ticket 12690.
    
      o Minor features (security, memory management):
        - Memory allocation tricks (mempools and buffer freelists) are now
          disabled by default. You can turn them back on with
          --enable-mempools and --enable-buf-freelists respectively. We're
          disabling these features because malloc performance is good enough
          on most platforms, and a similar feature in OpenSSL exacerbated
          exploitation of the Heartbleed attack. Resolves ticket 11476.
    
      o Minor features (bridge client):
        - Report a more useful failure message when we can't connect to a
          bridge because we don't have the right pluggable transport
          configured. Resolves ticket 9665. Patch from Fábio J. Bertinatto.
    
      o Minor features (bridge):
        - Add an ExtORPortCookieAuthFileGroupReadable option to make the
          cookie file for the ExtORPort g+r by default.
    
      o Minor features (bridges, pluggable transports):
        - Bridges now write the SHA1 digest of their identity key
          fingerprint (that is, a hash of a hash of their public key) to
          notice-level logs, and to a new hashed-fingerprint file. This
          information will help bridge operators look up their bridge in
          Globe and similar tools. Resolves ticket 10884.
        - Improve the message that Tor displays when running as a bridge
          using pluggable transports without an Extended ORPort listener.
          Also, log the message in the log file too. Resolves ticket 11043.
        - Add threshold cutoffs to the networkstatus document created by
          the Bridge Authority. Fixes bug 1117.
        - On Windows, spawn background processes using the CREATE_NO_WINDOW
          flag. Now Tor Browser Bundle 3.5 with pluggable transports enabled
          doesn't pop up a blank console window. (In Tor Browser Bundle 2.x,
          Vidalia set this option for us.) Implements ticket 10297.
    
      o Minor features (build):
        - The configure script has a --disable-seccomp option to turn off
          support for libseccomp on systems that have it, in case it (or
          Tor's use of it) is broken. Resolves ticket 11628.
        - Assume that a user using ./configure --host wants to cross-compile,
          and give an error if we cannot find a properly named
          tool-chain. Add a --disable-tool-name-check option to proceed
          nevertheless. Addresses ticket 9869. Patch by Benedikt Gollatz.
        - If we run ./configure and the compiler recognizes -fstack-protector
          but the linker rejects it, warn the user about a potentially missing
          libssp package. Addresses ticket 9948. Patch from Benedikt Gollatz.
        - Add support for `--library-versions` flag. Implements ticket 6384.
        - Return the "unexpected sendme" warnings to a warn severity, but make
          them rate limited, to help diagnose ticket 8093.
        - Detect a missing asciidoc, and warn the user about it, during
          configure rather than at build time. Fixes issue 6506. Patch from
          Arlo Breault.
    
      o Minor features (client):
        - Add a new option, PredictedPortsRelevanceTime, to control how long
          after having received a request to connect to a given port Tor
          will try to keep circuits ready in anticipation of future requests
          for that port. Patch from "unixninja92"; implements ticket 9176.
    
      o Minor features (config options and command line):
        - Add an --allow-missing-torrc commandline option that tells Tor to
          run even if the configuration file specified by -f is not available.
          Implements ticket 10060.
        - Add support for the TPROXY transparent proxying facility on Linux.
          See documentation for the new TransProxyType option for more
          details. Implementation by "thomo". Closes ticket 10582.
    
      o Minor features (config options):
        - Config (torrc) lines now handle fingerprints which are missing
          their initial '$'. Resolves ticket 4341; improvement over 0.0.9pre5.
        - Support a --dump-config option to print some or all of the
          configured options. Mainly useful for debugging the command-line
          option parsing code. Helps resolve ticket 4647.
        - Raise awareness of safer logging: notify user of potentially
          unsafe config options, like logging more verbosely than severity
          "notice" or setting SafeLogging to 0. Resolves ticket 5584.
        - Add a new configuration option TestingV3AuthVotingStartOffset
          that bootstraps a network faster by changing the timing for
          consensus votes. Addresses ticket 8532.
        - Add a new torrc option "ServerTransportOptions" that allows
          bridge operators to pass configuration parameters to their
          pluggable transports. Resolves ticket 8929.
        - The config (torrc) file now accepts bandwidth and space limits in
          bits as well as bytes. (Anywhere that you can say "2 Kilobytes",
          you can now say "16 kilobits", and so on.) Resolves ticket 9214.
          Patch by CharlieB.
    
      o Minor features (controller):
        - Make the entire exit policy available from the control port via
          GETINFO exit-policy/*. Implements enhancement 7952. Patch from
          "rl1987".
        - Because of the fix for ticket 11396, the real limit for memory
          usage may no longer match the configured MaxMemInQueues value. The
          real limit is now exposed via GETINFO limits/max-mem-in-queues.
        - Add a new "HS_DESC" controller event that reports activities
          related to hidden service descriptors. Resolves ticket 8510.
        - New "DROPGUARDS" controller command to forget all current entry
          guards. Not recommended for ordinary use, since replacing guards
          too frequently makes several attacks easier. Resolves ticket 9934;
          patch from "ra".
        - Implement the TRANSPORT_LAUNCHED control port event that
          notifies controllers about new launched pluggable
          transports. Resolves ticket 5609.
    
      o Minor features (diagnostic):
        - When logging a warning because of bug 7164, additionally check the
          hash table for consistency (as proposed on ticket 11737). This may
          help diagnose bug 7164.
        - When we log a heartbeat, log how many one-hop circuits we have
          that are at least 30 minutes old, and log status information about
          a few of them. This is an attempt to track down bug 8387.
        - When encountering an unexpected CR while writing text to a file on
          Windows, log the name of the file. Should help diagnosing
          bug 11233.
        - Give more specific warnings when a client notices that an onion
          handshake has failed. Fixes ticket 9635.
        - Add significant new logging code to attempt to diagnose bug 12184,
          where relays seem to run out of available circuit IDs.
        - Improve the diagnostic log message for bug 8387 even further to
          try to improve our odds of figuring out why one-hop directory
          circuits sometimes do not get closed.
        - Add more log messages to diagnose bug 7164, which causes
          intermittent "microdesc_free() called but md was still referenced"
          warnings. We now include more information, to figure out why we
          might be cleaning a microdescriptor for being too old if it's
          still referenced by a live node_t object.
        - Log current accounting state (bytes sent and received + remaining
          time for the current accounting period) in the relay's heartbeat
          message. Implements ticket 5526; patch from Peter Retzlaff.
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the August 7 2014 Maxmind GeoLite2
          Country database.
    
      o Minor features (interface):
        - Generate a warning if any ports are listed in the SocksPolicy,
          DirPolicy, AuthDirReject, AuthDirInvalid, AuthDirBadDir, or
          AuthDirBadExit options. (These options only support address
          ranges.) Fixes part of ticket 11108.
    
      o Minor features (kernel API usage):
        - Use the SOCK_NONBLOCK socket type, if supported, to open nonblocking
          sockets in a single system call. Implements ticket 5129.
    
      o Minor features (log messages):
        - When ServerTransportPlugin is set on a bridge, Tor can write more
          useful statistics about bridge use in its extrainfo descriptors,
          but only if the Extended ORPort ("ExtORPort") is set too. Add a
          log message to inform the user in this case. Resolves ticket 9651.
        - When receiving a new controller connection, log the origin address.
          Resolves ticket 9698; patch from "sigpipe".
        - When logging OpenSSL engine status at startup, log the status of
          more engines. Fixes ticket 10043; patch from Joshua Datko.
    
      o Minor features (log verbosity):
        - Demote the message that we give when a flushing connection times
          out for too long from NOTICE to INFO. It was usually meaningless.
          Resolves ticket 5286.
        - Don't log so many notice-level bootstrapping messages at startup
          about downloading descriptors. Previously, we'd log a notice
          whenever we learned about more routers. Now, we only log a notice
          at every 5% of progress. Fixes bug 9963.
        - Warn less verbosely when receiving a malformed
          ESTABLISH_RENDEZVOUS cell. Fixes ticket 11279.
    
      o Minor features (performance):
        - If we're using the pure-C 32-bit curve25519_donna implementation
          of curve25519, build it with the -fomit-frame-pointer option to
          make it go faster on register-starved hosts. This improves our
          handshake performance by about 6% on i386 hosts without nacl.
          Closes ticket 8109.
    
      o Minor features (relay):
        - If a circuit timed out for at least 3 minutes, check if we have a
          new external IP address, and publish a new descriptor with the new
          IP address if it changed. Resolves ticket 2454.
    
      o Minor features (testing):
        - If Python is installed, "make check" now runs extra tests beyond
          the unit test scripts.
        - When bootstrapping a test network, sometimes very few relays get
          the Guard flag. Now a new option "TestingDirAuthVoteGuard" can
          specify a set of relays which should be voted Guard regardless of
          their uptime or bandwidth. Addresses ticket 9206.
    
      o Minor features (transparent proxy, *BSD):
        - Support FreeBSD's ipfw firewall interface for TransPort ports on
          FreeBSD. To enable it, set "TransProxyType ipfw". Resolves ticket
          10267; patch from "yurivict".
        - Support OpenBSD's divert-to rules with the pf firewall for
          transparent proxy ports. To enable it, set "TransProxyType
          pf-divert". This allows Tor to run a TransPort transparent proxy
          port on OpenBSD 4.4 or later without root privileges. See the
          pf.conf(5) manual page for information on configuring pf to use
          divert-to rules. Closes ticket 10896; patch from Dana Koch.
    
      o Minor bugfixes (bridge client):
        - Stop accepting bridge lines containing hostnames. Doing so would
          cause clients to perform DNS requests on the hostnames, which was
          not sensible behavior. Fixes bug 10801; bugfix on 0.2.0.1-alpha.
    
      o Minor bugfixes (bridges):
        - Avoid potential crashes or bad behavior when launching a
          server-side managed proxy with ORPort or ExtORPort temporarily
          disabled. Fixes bug 9650; bugfix on 0.2.3.16-alpha.
        - Fix a bug where the first connection works to a bridge that uses a
          pluggable transport with client-side parameters, but we don't send
          the client-side parameters on subsequent connections. (We don't
          use any pluggable transports with client-side parameters yet,
          but ScrambleSuit will soon become the first one.) Fixes bug 9162;
          bugfix on 0.2.0.3-alpha. Based on a patch from "rl1987".
    
      o Minor bugfixes (build, auxiliary programs):
        - Stop preprocessing the "torify" script with autoconf, since
          it no longer refers to LOCALSTATEDIR. Fixes bug 5505; patch
          from Guilhem.
        - The tor-fw-helper program now follows the standard convention and
          exits with status code "0" on success. Fixes bug 9030; bugfix on
          0.2.3.1-alpha. Patch by Arlo Breault.
        - Corrected ./configure advice for what openssl dev package you should
          install on Debian. Fixes bug 9207; bugfix on 0.2.0.1-alpha.
    
      o Minor bugfixes (client):
        - Avoid "Tried to open a socket with DisableNetwork set" warnings
          when starting a client with bridges configured and DisableNetwork
          set. (Tor launcher starts Tor with DisableNetwork set the first
          time it runs.) Fixes bug 10405; bugfix on 0.2.3.9-alpha.
        - Improve the log message when we can't connect to a hidden service
          because all of the hidden service directory nodes hosting its
          descriptor are excluded. Improves on our fix for bug 10722, which
          was a bugfix on 0.2.0.10-alpha.
        - Raise a control port warning when we fail to connect to all of
          our bridges. Previously, we didn't inform the controller, and
          the bootstrap process would stall. Fixes bug 11069; bugfix on
          0.2.1.2-alpha.
        - Exit immediately when a process-owning controller exits.
          Previously, tor relays would wait for a little while after their
          controller exited, as if they had gotten an INT signal -- but this
          was problematic, since there was no feedback for the user. To do a
          clean shutdown, controllers should send an INT signal and give Tor
          a chance to clean up. Fixes bug 10449; bugfix on 0.2.2.28-beta.
        - Stop attempting to connect to bridges before our pluggable
          transports are configured (harmless but resulted in some erroneous
          log messages). Fixes bug 11156; bugfix on 0.2.3.2-alpha.
        - Fix connections to IPv6 addresses over SOCKS5. Previously, we were
          generating incorrect SOCKS5 responses, and confusing client
          applications. Fixes bug 10987; bugfix on 0.2.4.7-alpha.
    
      o Minor bugfixes (client, DNSPort):
        - When using DNSPort, try to respond to AAAA requests with AAAA
          answers. Previously, we hadn't looked at the request type when
          deciding which answer type to prefer. Fixes bug 10468; bugfix on
          0.2.4.7-alpha.
        - When receiving a DNS query for an unsupported record type, reply
          with no answer rather than with a NOTIMPL error. This behavior
          isn't correct either, but it will break fewer client programs, we
          hope. Fixes bug 10268; bugfix on 0.2.0.1-alpha. Original patch
          from "epoch".
    
      o Minor bugfixes (client, logging during bootstrap):
        - Only report the first fatal bootstrap error on a given OR
          connection. This stops us from telling the controller bogus error
          messages like "DONE". Fixes bug 10431; bugfix on 0.2.1.1-alpha.
        - Avoid generating spurious warnings when starting with
          DisableNetwork enabled. Fixes bug 11200 and bug 10405; bugfix on
          0.2.3.9-alpha.
    
      o Minor bugfixes (closing OR connections):
        - If write_to_buf() in connection_write_to_buf_impl_() ever fails,
          check if it's an or_connection_t and correctly call
          connection_or_close_for_error() rather than
          connection_mark_for_close() directly. Fixes bug 11304; bugfix on
          0.2.4.4-alpha.
        - When closing all connections on setting DisableNetwork to 1, use
          connection_or_close_normally() rather than closing OR connections
          out from under the channel layer. Fixes bug 11306; bugfix on
          0.2.4.4-alpha.
    
      o Minor bugfixes (code correctness):
        - Previously we used two temporary files when writing descriptors to
          disk; now we only use one. Fixes bug 1376.
        - Remove an erroneous (but impossible and thus harmless) pointer
          comparison that would have allowed compilers to skip a bounds
          check in channeltls.c. Fixes bugs 10313 and 9980; bugfix on
          0.2.0.10-alpha. Noticed by Jared L Wong and David Fifield.
        - Fix an always-true assertion in pluggable transports code so it
          actually checks what it was trying to check. Fixes bug 10046;
          bugfix on 0.2.3.9-alpha. Found by "dcb".
    
      o Minor bugfixes (command line):
        - Use a single command-line parser for parsing torrc options on the
          command line and for finding special command-line options to avoid
          inconsistent behavior for torrc option arguments that have the same
          names as command-line options. Fixes bugs 4647 and 9578; bugfix on
          0.0.9pre5.
        - No longer allow 'tor --hash-password' with no arguments. Fixes bug
          9573; bugfix on 0.0.9pre5.
    
      o Minor bugfixes (compilation):
        - Compile correctly with builds and forks of OpenSSL (such as
          LibreSSL) that disable compression. Fixes bug 12602; bugfix on
          0.2.1.1-alpha. Patch from "dhill".
        - Restore the ability to compile Tor with V2_HANDSHAKE_SERVER
          turned off (that is, without support for v2 link handshakes). Fixes
          bug 4677; bugfix on 0.2.3.2-alpha. Patch from "piet".
        - In routerlist_assert_ok(), don't take the address of a
          routerinfo's cache_info member unless that routerinfo is non-NULL.
          Fixes bug 13096; bugfix on 0.1.1.9-alpha. Patch by "teor".
        - Fix a large number of false positive warnings from the clang
          analyzer static analysis tool. This should make real warnings
          easier for clang analyzer to find. Patch from "teor". Closes
          ticket 13036.
        - Resolve GCC complaints on OpenBSD about discarding constness in
          TO_{ORIGIN,OR}_CIRCUIT functions. Fixes part of bug 11633; bugfix
          on 0.1.1.23. Patch from Dana Koch.
        - Resolve clang complaints on OpenBSD with -Wshorten-64-to-32 due to
          treatment of long and time_t as comparable types. Fixes part of
          bug 11633. Patch from Dana Koch.
        - When deciding whether to build the 64-bit curve25519
          implementation, detect platforms where we can compile 128-bit
          arithmetic but cannot link it. Fixes bug 11729; bugfix on
          0.2.4.8-alpha. Patch from "conradev".
        - Fix compilation when DNS_CACHE_DEBUG is enabled. Fixes bug 11761;
          bugfix on 0.2.3.13-alpha. Found by "cypherpunks".
        - Fix compilation with dmalloc. Fixes bug 11605; bugfix
          on 0.2.4.10-alpha.
        - Build and run correctly on systems like OpenBSD-current that have
          patched OpenSSL to remove get_cipher_by_char and/or its
          implementations. Fixes issue 13325.
    
      o Minor bugfixes (controller and command-line):
        - If changing a config option via "setconf" fails in a recoverable
          way, we used to nonetheless write our new control ports to the
          file described by the "ControlPortWriteToFile" option. Now we only
          write out that file if we successfully switch to the new config
          option. Fixes bug 5605; bugfix on 0.2.2.26-beta. Patch from "Ryman".
    
      o Minor bugfixes (directory server):
        - No longer accept malformed http headers when parsing urls from
          headers. Now we reply with Bad Request ("400"). Fixes bug 2767;
          bugfix on 0.0.6pre1.
        - When sending a compressed set of descriptors or microdescriptors,
          make sure to finalize the zlib stream. Previously, we would write
          all the compressed data, but if the last descriptor we wanted to
          send was missing or too old, we would not mark the stream as
          finished. This caused problems for decompression tools. Fixes bug
          11648; bugfix on 0.1.1.23.
    
      o Minor bugfixes (hidden service):
        - Only retry attempts to connect to a chosen rendezvous point 8
          times, not 30. Fixes bug 4241; bugfix on 0.1.0.1-rc.
    
      o Minor bugfixes (interface):
        - Reject relative control socket paths and emit a warning. Previously,
          single-component control socket paths would be rejected, but Tor
          would not log why it could not validate the config. Fixes bug 9258;
          bugfix on 0.2.3.16-alpha.
    
      o Minor bugfixes (log messages):
        - Fix a bug where clients using bridges would report themselves
          as 50% bootstrapped even without a live consensus document.
          Fixes bug 9922; bugfix on 0.2.1.1-alpha.
        - Suppress a warning where, if there's only one directory authority
          in the network, we would complain that votes and signatures cannot
          be uploaded to other directory authorities. Fixes bug 10842;
          bugfix on 0.2.2.26-beta.
        - Report bootstrapping progress correctly when we're downloading
          microdescriptors. We had updated our "do we have enough microdescs
          to begin building circuits?" logic most recently in 0.2.4.10-alpha
          (see bug 5956), but we left the bootstrap status event logic at
          "how far through getting 1/4 of them are we?" Fixes bug 9958;
          bugfix on 0.2.2.36, which is where they diverged (see bug 5343).
    
      o Minor bugfixes (logging):
        - Downgrade "Unexpected onionskin length after decryption" warning
          to a protocol-warn, since there's nothing relay operators can do
          about a client that sends them a malformed create cell. Resolves
          bug 12996; bugfix on 0.0.6rc1.
        - Log more specific warnings when we get an ESTABLISH_RENDEZVOUS
          cell on a cannibalized or non-OR circuit. Resolves ticket 12997.
        - When logging information about an EXTEND2 or EXTENDED2 cell, log
          their names correctly. Fixes part of bug 12700; bugfix
          on 0.2.4.8-alpha.
        - When logging information about a relay cell whose command we don't
          recognize, log its command as an integer. Fixes part of bug 12700;
          bugfix on 0.2.1.10-alpha.
        - Escape all strings from the directory connection before logging
          them. Fixes bug 13071; bugfix on 0.1.1.15. Patch from "teor".
        - Squelch a spurious LD_BUG message "No origin circuit for
          successful SOCKS stream" in certain hidden service failure cases;
          fixes bug 10616.
        - Downgrade the severity of the 'unexpected sendme cell from client'
          from 'warn' to 'protocol warning'. Closes ticket 8093.
    
      o Minor bugfixes (misc code correctness):
        - In munge_extrainfo_into_routerinfo(), check the return value of
          memchr(). This would have been a serious issue if we ever passed
          it a non-extrainfo. Fixes bug 8791; bugfix on 0.2.0.6-alpha. Patch
          from Arlo Breault.
        - On the chance that somebody manages to build Tor on a
          platform where time_t is unsigned, correct the way that
          microdesc_add_to_cache() handles negative time arguments.
          Fixes bug 8042; bugfix on 0.2.3.1-alpha.
        - Fix various instances of undefined behavior in channeltls.c,
          tor_memmem(), and eventdns.c that would cause us to construct
          pointers to memory outside an allocated object. (These invalid
          pointers were not accessed, but C does not even allow them to
          exist.) Fixes bug 10363; bugfixes on 0.1.1.1-alpha, 0.1.2.1-alpha,
          0.2.0.10-alpha, and 0.2.3.6-alpha. Reported by "bobnomnom".
        - Use the AddressSanitizer and Ubsan sanitizers (in clang-3.4) to
          fix some miscellaneous errors in our tests and codebase. Fixes bug
          11232. Bugfixes on versions back as far as 0.2.1.11-alpha.
        - Always check return values for unlink, munmap, UnmapViewOfFile;
          check strftime return values more often. In some cases all we can
          do is report a warning, but this may help prevent deeper bugs from
          going unnoticed. Closes ticket 8787; bugfixes on many, many tor
          versions.
        - Fix numerous warnings from the clang "scan-build" static analyzer.
          Some of these are programming style issues; some of them are false
          positives that indicated awkward code; some are undefined behavior
          cases related to constructing (but not using) invalid pointers;
          some are assumptions about API behavior; some are (harmlessly)
          logging sizeof(ptr) bytes from a token when sizeof(*ptr) would be
          correct; and one or two are genuine bugs that weren't reachable
          from the rest of the program. Fixes bug 8793; bugfixes on many,
          many tor versions.
    
      o Minor bugfixes (node selection):
        - If ExcludeNodes is set, consider non-excluded hidden service
          directory servers before excluded ones. Do not consider excluded
          hidden service directory servers at all if StrictNodes is
          set. (Previously, we would sometimes decide to connect to those
          servers, and then realize before we initiated a connection that
          we had excluded them.) Fixes bug 10722; bugfix on 0.2.0.10-alpha.
          Reported by "mr-4".
        - If we set the ExitNodes option but it doesn't include any nodes
          that have the Exit flag, we would choose not to bootstrap. Now we
          bootstrap so long as ExitNodes includes nodes which can exit to
          some port. Fixes bug 10543; bugfix on 0.2.4.10-alpha.
    
      o Minor bugfixes (performance):
        - Avoid a bug where every successful connection made us recompute
          the flag telling us whether we have sufficient information to
          build circuits. Previously, we would forget our cached value
          whenever we successfully opened a channel (or marked a router as
          running or not running for any other reason), regardless of
          whether we had previously believed the router to be running. This
          forced us to run an expensive update operation far too often.
          Fixes bug 12170; bugfix on 0.1.2.1-alpha.
        - Avoid using tor_memeq() for checking relay cell integrity. This
          removes a possible performance bottleneck. Fixes part of bug
          12169; bugfix on 0.2.1.31.
    
      o Minor bugfixes (platform-specific):
        - When dumping a malformed directory object to disk, save it in
          binary mode on Windows, not text mode. Fixes bug 11342; bugfix on
          0.2.2.1-alpha.
        - Don't report failures from make_socket_reuseable() on incoming
          sockets on OSX: this can happen when incoming connections close
          early. Fixes bug 10081.
    
      o Minor bugfixes (pluggable transports):
        - Avoid another 60-second delay when starting Tor in a pluggable-
          transport-using configuration when we already have cached
          descriptors for our bridges. Fixes bug 11965; bugfix
          on 0.2.3.6-alpha.
    
      o Minor bugfixes (protocol correctness):
        - When receiving a VERSIONS cell with an odd number of bytes, close
          the connection immediately since the cell is malformed. Fixes bug
          10365; bugfix on 0.2.0.10-alpha. Spotted by "bobnomnom"; fix by
          "rl1987".
    
      o Minor bugfixes (relay, other):
        - We now drop CREATE cells for already-existent circuit IDs and for
          zero-valued circuit IDs, regardless of other factors that might
          otherwise have called for DESTROY cells. Fixes bug 12191; bugfix
          on 0.0.8pre1.
        - When rejecting DATA cells for stream_id zero, still count them
          against the circuit's deliver window so that we don't fail to send
          a SENDME. Fixes bug 11246; bugfix on 0.2.4.10-alpha.
    
      o Minor bugfixes (relay, threading):
        - Check return code on spawn_func() in cpuworker code, so that we
          don't think we've spawned a nonworking cpuworker and write junk to
          it forever. Fix related to bug 4345; bugfix on all released Tor
          versions. Found by "skruffy".
        - Use a pthread_attr to make sure that spawn_func() cannot return an
          error while at the same time launching a thread. Fix related to
          bug 4345; bugfix on all released Tor versions. Reported
          by "cypherpunks".
    
      o Minor bugfixes (relays and bridges):
        - Avoid crashing on a malformed resolv.conf file when running a
          relay using Libevent 1. Fixes bug 8788; bugfix on 0.1.1.23.
        - Non-exit relays no longer launch mock DNS requests to check for
          DNS hijacking. This has been unnecessary since 0.2.1.7-alpha, when
          non-exit relays stopped servicing DNS requests. Fixes bug 965;
          bugfix on 0.2.1.7-alpha. Patch from Matt Pagan.
        - Bridges now report complete directory request statistics. Related
          to bug 5824; bugfix on 0.2.2.1-alpha.
        - Bridges now never collect statistics that were designed for
          relays. Fixes bug 5824; bugfix on 0.2.3.8-alpha.
    
      o Minor bugfixes (testing):
        - Fix all valgrind warnings produced by the unit tests. There were
          over a thousand memory leak warnings previously, mostly produced
          by forgetting to free things in the unit test code. Fixes bug
          11618, bugfixes on many versions of Tor.
    
      o Minor bugfixes (tor-fw-helper):
        - Give a correct log message when tor-fw-helper fails to launch.
          (Previously, we would say something like "tor-fw-helper sent us a
          string we could not parse".) Fixes bug 9781; bugfix
          on 0.2.4.2-alpha.
    
      o Minor bugfixes (trivial memory leaks):
        - Fix a small memory leak when signing a directory object. Fixes bug
          11275; bugfix on 0.2.4.13-alpha.
        - Resolve some memory leaks found by coverity in the unit tests, on
          exit in tor-gencert, and on a failure to compute digests for our
          own keys when generating a v3 networkstatus vote. These leaks
          should never have affected anyone in practice.
    
      o Code simplification and refactoring:
        - Remove some old fallback code designed to keep Tor clients working
          in a network with only two working relays. Elsewhere in the code we
          have long since stopped supporting such networks, so there wasn't
          much point in keeping it around. Addresses ticket 9926.
        - Reject 0-length EXTEND2 cells more explicitly. Fixes bug 10536;
          bugfix on 0.2.4.8-alpha. Reported by "cypherpunks".
        - Extract the common duplicated code for creating a subdirectory
          of the data directory and writing to a file in it. Fixes ticket
          4282; patch from Peter Retzlaff.
        - Since OpenSSL 0.9.7, the i2d_*() functions support allocating output
          buffer. Avoid calling twice: i2d_RSAPublicKey(), i2d_DHparams(),
          i2d_X509(), and i2d_PublicKey(). Resolves ticket 5170.
        - Add a set of accessor functions for the circuit timeout data
          structure. Fixes ticket 6153; patch from "piet".
        - Clean up exit paths from connection_listener_new(). Closes ticket
          8789. Patch from Arlo Breault.
        - Since we rely on OpenSSL 0.9.8 now, we can use EVP_PKEY_cmp()
          and drop our own custom pkey_eq() implementation. Fixes bug 9043.
        - Use a doubly-linked list to implement the global circuit list.
          Resolves ticket 9108. Patch from Marek Majkowski.
        - Remove contrib/id_to_fp.c since it wasn't used anywhere.
        - Remove constants and tests for PKCS1 padding; it's insecure and
          shouldn't be used for anything new. Fixes bug 8792; patch
          from Arlo Breault.
        - Remove instances of strcpy() from the unit tests. They weren't
          hurting anything, since they were only in the unit tests, but it's
          embarrassing to have strcpy() in the code at all, and some analysis
          tools don't like it. Fixes bug 8790; bugfix on 0.2.3.6-alpha and
          0.2.3.8-alpha. Patch from Arlo Breault.
        - Remove is_internal_IP() function. Resolves ticket 4645.
        - Remove unused function circuit_dump_by_chan from circuitlist.c.
          Closes issue 9107; patch from "marek".
        - Change our use of the ENUM_BF macro to avoid declarations that
          confuse Doxygen.
        - Get rid of router->address, since in all cases it was just the
          string representation of router->addr. Resolves ticket 5528.
    
      o Documentation:
        - Adjust the URLs in the README to refer to the new locations of
          several documents on the website. Fixes bug 12830. Patch from
          Matt Pagan.
        - Document 'reject6' and 'accept6' ExitPolicy entries. Resolves
          ticket 12878.
        - Update manpage to describe some of the files you can expect to
          find in Tor's DataDirectory. Addresses ticket 9839.
        - Clean up several option names in the manpage to match their real
          names, add the missing documentation for a couple of testing and
          directory authority options, remove the documentation for a
          V2-directory fetching option that no longer exists. Resolves
          ticket 11634.
        - Correct the documentation so that it lists the correct directory
          for the stats files. (They are in a subdirectory called "stats",
          not "status".)
        - In the manpage, move more authority-only options into the
          directory authority section so that operators of regular directory
          caches don't get confused.
        - Fix the layout of the SOCKSPort flags in the manpage. Fixes bug
          11061; bugfix on 0.2.4.7-alpha.
        - Resolve warnings from Doxygen.
        - Document in the manpage that "KBytes" may also be written as
          "kilobytes" or "KB", that "Kbits" may also be written as
          "kilobits", and so forth. Closes ticket 9222.
        - Document that the ClientOnly config option overrides ORPort.
          Our old explanation made ClientOnly sound as though it did
          nothing at all. Resolves bug 9059.
        - Explain that SocksPolicy, DirPolicy, and similar options don't
          take port arguments. Fixes the other part of ticket 11108.
        - Fix a comment about the rend_server_descriptor_t.protocols field
          to more accurately describe its range. Also, make that field
          unsigned, to more accurately reflect its usage. Fixes bug 9099;
          bugfix on 0.2.1.5-alpha.
        - Fix the manpage's description of HiddenServiceAuthorizeClient:
          the maximum client name length is 16, not 19. Fixes bug 11118;
          bugfix on 0.2.1.6-alpha.
    
      o Package cleanup:
        - The contrib directory has been sorted and tidied. Before, it was
          an unsorted dumping ground for useful and not-so-useful things.
          Now, it is divided based on functionality, and the items which
          seemed to be nonfunctional or useless have been removed. Resolves
          ticket 8966; based on patches from "rl1987".
    
      o Removed code and features:
        - Clients now reject any directory authority certificates lacking
          a dir-key-crosscert element. These have been included since
          0.2.1.9-alpha, so there's no real reason for them to be optional
          any longer. Completes proposal 157. Resolves ticket 10162.
        - Remove all code that existed to support the v2 directory system,
          since there are no longer any v2 directory authorities. Resolves
          ticket 10758.
        - Remove the HSAuthoritativeDir and AlternateHSAuthority torrc
          options, which were used for designating authorities as "Hidden
          service authorities". There has been no use of hidden service
          authorities since 0.2.2.1-alpha, when we stopped uploading or
          downloading v0 hidden service descriptors. Fixes bug 10881; also
          part of a fix for bug 10841.
        - Remove /tor/dbg-stability.txt URL that was meant to help debug WFU
          and MTBF calculations, but that nobody was using. Fixes bug 11742.
        - The TunnelDirConns and PreferTunnelledDirConns options no longer
          exist; tunneled directory connections have been available since
          0.1.2.5-alpha, and turning them off is not a good idea. This is a
          brute-force fix for 10849, where "TunnelDirConns 0" would break
          hidden services.
        - Remove all code for the long unused v1 directory protocol.
          Resolves ticket 11070.
        - Remove all remaining code related to version-0 hidden service
          descriptors: they have not been in use since 0.2.2.1-alpha. Fixes
          the rest of bug 10841.
        - Remove migration code from when we renamed the "cached-routers"
          file to "cached-descriptors" back in 0.2.0.8-alpha. This
          incidentally resolves ticket 6502 by cleaning up the related code
          a bit. Patch from Akshay Hebbar.
    
      o Test infrastructure:
        - Tor now builds each source file in two modes: a mode that avoids
          exposing identifiers needlessly, and another mode that exposes
          more identifiers for testing. This lets the compiler do better at
          optimizing the production code, while enabling us to take more
          radical measures to let the unit tests test things.
        - The production builds no longer include functions used only in
          the unit tests; all functions exposed from a module only for
          unit-testing are now static in production builds.
        - Add an --enable-coverage configuration option to make the unit
          tests (and a new src/or/tor-cov target) to build with gcov test
          coverage support.
        - Update to the latest version of tinytest.
        - Improve the tinytest implementation of string operation tests so
          that comparisons with NULL strings no longer crash the tests; they
          now just fail, normally. Fixes bug 9004; bugfix on 0.2.2.4-alpha.
        - New macros in test.h to simplify writing mock-functions for unit
          tests. Part of ticket 11507. Patch from Dana Koch.
        - We now have rudimentary function mocking support that our unit
          tests can use to test functions in isolation. Function mocking
          lets the tests temporarily replace a function's dependencies with
          stub functions, so that the tests can check the function without
          invoking the other functions it calls.
    
      o Testing:
        - Complete tests for the status.c module. Resolves ticket 11507.
          Patch from Dana Koch.
        - Add more unit tests for the <circid,channel>->circuit map, and
          the destroy-cell-tracking code to fix bug 7912.
        - Unit tests for failing cases of the TAP onion handshake.
        - More unit tests for address-manipulation functions.
    
      o Distribution (systemd):
        - Include a tor.service file in contrib/dist for use with systemd.
          Some distributions will be able to use this file unmodified;
          others will need to tweak it, or write their own. Patch from Jamie
          Nguyen; resolves ticket 8368.
        - Verify configuration file via ExecStartPre in the systemd unit
          file. Patch from intrigeri; resolves ticket 12730.
        - Explicitly disable RunAsDaemon in the systemd unit file. Our
          current systemd unit uses "Type = simple", so systemd does not
          expect tor to fork. If the user has "RunAsDaemon 1" in their
          torrc, then things won't work as expected. This is e.g. the case
          on Debian (and derivatives), since there we pass "--defaults-torrc
          /usr/share/tor/tor-service-defaults-torrc" (that contains
          "RunAsDaemon 1") by default. Patch by intrigeri; resolves
          ticket 12731.
    
    
    Changes in version 0.2.4.25 - 2014-10-20
      Tor 0.2.4.25 disables SSL3 in response to the recent "POODLE" attack
      (even though POODLE does not affect Tor). It also works around a crash
      bug caused by some operating systems' response to the "POODLE" attack
      (which does affect Tor).
    
      o Major security fixes (also in 0.2.5.9-rc):
        - Disable support for SSLv3. All versions of OpenSSL in use with Tor
          today support TLS 1.0 or later, so we can safely turn off support
          for this old (and insecure) protocol. Fixes bug 13426.
    
      o Major bugfixes (openssl bug workaround, also in 0.2.5.9-rc):
        - Avoid crashing when using OpenSSL version 0.9.8zc, 1.0.0o, or
          1.0.1j, built with the 'no-ssl3' configuration option. Fixes bug
          13471. This is a workaround for an OpenSSL bug.
    
    
    Changes in version 0.2.4.24 - 2014-09-22
      Tor 0.2.4.24 fixes a bug that affects consistency and speed when
      connecting to hidden services, and it updates the location of one of
      the directory authorities.
    
      o Major bugfixes:
        - Clients now send the correct address for their chosen rendezvous
          point when trying to access a hidden service. They used to send
          the wrong address, which would still work some of the time because
          they also sent the identity digest of the rendezvous point, and if
          the hidden service happened to try connecting to the rendezvous
          point from a relay that already had a connection open to it,
          the relay would reuse that connection. Now connections to hidden
          services should be more robust and faster. Also, this bug meant
          that clients were leaking to the hidden service whether they were
          on a little-endian (common) or big-endian (rare) system, which for
          some users might have reduced their anonymity. Fixes bug 13151;
          bugfix on 0.2.1.5-alpha.
    
      o Directory authority changes:
        - Change IP address for gabelmoo (v3 directory authority).
    
      o Minor features (geoip):
        - Update geoip and geoip6 to the August 7 2014 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.4.23 - 2014-07-28
      Tor 0.2.4.23 brings us a big step closer to slowing down the risk from
      guard rotation, and also backports several important fixes from the
      Tor 0.2.5 alpha release series.
    
      o Major features:
        - Clients now look at the "usecreatefast" consensus parameter to
          decide whether to use CREATE_FAST or CREATE cells for the first hop
          of their circuit. This approach can improve security on connections
          where Tor's circuit handshake is stronger than the available TLS
          connection security levels, but the tradeoff is more computational
          load on guard relays. Implements proposal 221. Resolves ticket 9386.
        - Make the number of entry guards configurable via a new
          NumEntryGuards consensus parameter, and the number of directory
          guards configurable via a new NumDirectoryGuards consensus
          parameter. Implements ticket 12688.
    
      o Major bugfixes:
        - Fix a bug in the bounds-checking in the 32-bit curve25519-donna
          implementation that caused incorrect results on 32-bit
          implementations when certain malformed inputs were used along with
          a small class of private ntor keys. This bug does not currently
          appear to allow an attacker to learn private keys or impersonate a
          Tor server, but it could provide a means to distinguish 32-bit Tor
          implementations from 64-bit Tor implementations. Fixes bug 12694;
          bugfix on 0.2.4.8-alpha. Bug found by Robert Ransom; fix from
          Adam Langley.
    
      o Minor bugfixes:
        - Warn and drop the circuit if we receive an inbound 'relay early'
          cell. Those used to be normal to receive on hidden service circuits
          due to bug 1038, but the buggy Tor versions are long gone from
          the network so we can afford to resume watching for them. Resolves
          the rest of bug 1038; bugfix on 0.2.1.19.
        - Correct a confusing error message when trying to extend a circuit
          via the control protocol but we don't know a descriptor or
          microdescriptor for one of the specified relays. Fixes bug 12718;
          bugfix on 0.2.3.1-alpha.
        - Avoid an illegal read from stack when initializing the TLS
          module using a version of OpenSSL without all of the ciphers
          used by the v2 link handshake. Fixes bug 12227; bugfix on
          0.2.4.8-alpha.  Found by "starlight".
    
      o Minor features:
        - Update geoip and geoip6 to the July 10 2014 Maxmind GeoLite2
          Country database.
    
    
    Changes in version 0.2.4.22 - 2014-05-16
      Tor 0.2.4.22 backports numerous high-priority fixes from the Tor 0.2.5
      alpha release series. These include blocking all authority signing
      keys that may have been affected by the OpenSSL "heartbleed" bug,
      choosing a far more secure set of TLS ciphersuites by default, closing
      a couple of memory leaks that could be used to run a target relay out
      of RAM, and several others.
    
      o Major features (security, backport from 0.2.5.4-alpha):
        - Block authority signing keys that were used on authorities
          vulnerable to the "heartbleed" bug in OpenSSL (CVE-2014-0160). (We
          don't have any evidence that these keys _were_ compromised; we're
          doing this to be prudent.) Resolves ticket 11464.
    
      o Major bugfixes (security, OOM):
        - Fix a memory leak that could occur if a microdescriptor parse
          fails during the tokenizing step. This bug could enable a memory
          exhaustion attack by directory servers. Fixes bug 11649; bugfix
          on 0.2.2.6-alpha.
    
      o Major bugfixes (TLS cipher selection, backport from 0.2.5.4-alpha):
        - The relay ciphersuite list is now generated automatically based on
          uniform criteria, and includes all OpenSSL ciphersuites with
          acceptable strength and forward secrecy. Previously, we had left
          some perfectly fine ciphersuites unsupported due to omission or
          typo. Resolves bugs 11513, 11492, 11498, 11499. Bugs reported by
          'cypherpunks'. Bugfix on 0.2.4.8-alpha.
        - Relays now trust themselves to have a better view than clients of
          which TLS ciphersuites are better than others. (Thanks to bug
          11513, the relay list is now well-considered, whereas the client
          list has been chosen mainly for anti-fingerprinting purposes.)
          Relays prefer: AES over 3DES; then ECDHE over DHE; then GCM over
          CBC; then SHA384 over SHA256 over SHA1; and last, AES256 over
          AES128. Resolves ticket 11528.
        - Clients now try to advertise the same list of ciphersuites as
          Firefox 28. This change enables selection of (fast) GCM
          ciphersuites, disables some strange old ciphers, and stops
          advertising the ECDH (not to be confused with ECDHE) ciphersuites.
          Resolves ticket 11438.
    
      o Minor bugfixes (configuration, security):
        - When running a hidden service, do not allow TunneledDirConns 0:
          trying to set that option together with a hidden service would
          otherwise prevent the hidden service from running, and also make
          it publish its descriptors directly over HTTP. Fixes bug 10849;
          bugfix on 0.2.1.1-alpha.
    
      o Minor bugfixes (controller, backport from 0.2.5.4-alpha):
        - Avoid sending a garbage value to the controller when a circuit is
          cannibalized. Fixes bug 11519; bugfix on 0.2.3.11-alpha.
    
      o Minor bugfixes (exit relay, backport from 0.2.5.4-alpha):
        - Stop leaking memory when we successfully resolve a PTR record.
          Fixes bug 11437; bugfix on 0.2.4.7-alpha.
    
      o Minor bugfixes (bridge client, backport from 0.2.5.4-alpha):
        - Avoid 60-second delays in the bootstrapping process when Tor is
          launching for a second time while using bridges. Fixes bug 9229;
          bugfix on 0.2.0.3-alpha.
    
      o Minor bugfixes (relays and bridges, backport from 0.2.5.4-alpha):
        - Give the correct URL in the warning message when trying to run a
          relay on an ancient version of Windows. Fixes bug 9393.
    
      o Minor bugfixes (compilation):
        - Fix a compilation error when compiling with --disable-curve25519.
          Fixes bug 9700; bugfix on 0.2.4.17-rc.
    
      o Minor bugfixes:
        - Downgrade the warning severity for the the "md was still
          referenced 1 node(s)" warning. Tor 0.2.5.4-alpha has better code
          for trying to diagnose this bug, and the current warning in
          earlier versions of tor achieves nothing useful. Addresses warning
          from bug 7164.
    
      o Minor features (log verbosity, backport from 0.2.5.4-alpha):
        - When we run out of usable circuit IDs on a channel, log only one
          warning for the whole channel, and describe how many circuits
          there were on the channel. Fixes part of ticket 11553.
    
      o Minor features (security, backport from 0.2.5.4-alpha):
        - Decrease the lower limit of MaxMemInCellQueues to 256 MBytes (but
          leave the default at 8GBytes), to better support Raspberry Pi
          users. Fixes bug 9686; bugfix on 0.2.4.14-alpha.
    
      o Documentation (backport from 0.2.5.4-alpha):
        - Correctly document that we search for a system torrc file before
          looking in ~/.torrc. Fixes documentation side of 9213; bugfix on
          0.2.3.18-rc.
    
    
    Changes in version 0.2.4.21 - 2014-02-28
      Tor 0.2.4.21 further improves security against potential adversaries who
      find breaking 1024-bit crypto doable, and backports several stability
      and robustness patches from the 0.2.5 branch.
    
      o Major features (client security):
        - When we choose a path for a 3-hop circuit, make sure it contains
          at least one relay that supports the NTor circuit extension
          handshake. Otherwise, there is a chance that we're building
          a circuit that's worth attacking by an adversary who finds
          breaking 1024-bit crypto doable, and that chance changes the game
          theory. Implements ticket 9777.
    
      o Major bugfixes:
        - Do not treat streams that fail with reason
          END_STREAM_REASON_INTERNAL as indicating a definite circuit failure,
          since it could also indicate an ENETUNREACH connection error. Fixes
          part of bug 10777; bugfix on 0.2.4.8-alpha.
    
      o Code simplification and refactoring:
        - Remove data structures which were introduced to implement the
          CellStatistics option: they are now redundant with the new timestamp
          field in the regular packed_cell_t data structure, which we did
          in 0.2.4.18-rc in order to resolve bug 9093. Resolves ticket 10870.
    
      o Minor features:
        - Always clear OpenSSL bignums before freeing them -- even bignums
          that don't contain secrets. Resolves ticket 10793. Patch by
          Florent Daigniere.
        - Build without warnings under clang 3.4. (We have some macros that
          define static functions only some of which will get used later in
          the module. Starting with clang 3.4, these give a warning unless the
          unused attribute is set on them.) Resolves ticket 10904.
        - Update geoip and geoip6 files to the February 7 2014 Maxmind
          GeoLite2 Country database.
    
      o Minor bugfixes:
        - Set the listen() backlog limit to the largest actually supported
          on the system, not to the value in a header file. Fixes bug 9716;
          bugfix on every released Tor.
        - Treat ENETUNREACH, EACCES, and EPERM connection failures at an
          exit node as a NOROUTE error, not an INTERNAL error, since they
          can apparently happen when trying to connect to the wrong sort
          of netblocks. Fixes part of bug 10777; bugfix on 0.1.0.1-rc.
        - Fix build warnings about missing "a2x" comment when building the
          manpages from scratch on OpenBSD; OpenBSD calls it "a2x.py".
          Fixes bug 10929; bugfix on 0.2.2.9-alpha. Patch from Dana Koch.
        - Avoid a segfault on SIGUSR1, where we had freed a connection but did
          not entirely remove it from the connection lists. Fixes bug 9602;
          bugfix on 0.2.4.4-alpha.
        - Fix a segmentation fault in our benchmark code when running with
          Fedora's OpenSSL package, or any other OpenSSL that provides
          ECDH but not P224. Fixes bug 10835; bugfix on 0.2.4.8-alpha.
        - Turn "circuit handshake stats since last time" log messages into a
          heartbeat message. Fixes bug 10485; bugfix on 0.2.4.17-rc.
    
      o Documentation fixes:
        - Document that all but one DirPort entry must have the NoAdvertise
          flag set. Fixes bug 10470; bugfix on 0.2.3.3-alpha / 0.2.3.16-alpha.
    
    
    Changes in version 0.2.4.20 - 2013-12-22
      Tor 0.2.4.20 fixes potentially poor random number generation for users
      who 1) use OpenSSL 1.0.0 or later, 2) set "HardwareAccel 1" in their
      torrc file, 3) have "Sandy Bridge" or "Ivy Bridge" Intel processors,
      and 4) have no state file in their DataDirectory (as would happen on
      first start). Users who generated relay or hidden service identity
      keys in such a situation should discard them and generate new ones.
    
      This release also fixes a logic error that caused Tor clients to build
      many more preemptive circuits than they actually need.
    
      o Major bugfixes:
        - Do not allow OpenSSL engines to replace the PRNG, even when
          HardwareAccel is set. The only default builtin PRNG engine uses
          the Intel RDRAND instruction to replace the entire PRNG, and
          ignores all attempts to seed it with more entropy. That's
          cryptographically stupid: the right response to a new alleged
          entropy source is never to discard all previously used entropy
          sources. Fixes bug 10402; works around behavior introduced in
          OpenSSL 1.0.0. Diagnosis and investigation thanks to "coderman"
          and "rl1987".
        - Fix assertion failure when AutomapHostsOnResolve yields an IPv6
          address. Fixes bug 10465; bugfix on 0.2.4.7-alpha.
        - Avoid launching spurious extra circuits when a stream is pending.
          This fixes a bug where any circuit that _wasn't_ unusable for new
          streams would be treated as if it were, causing extra circuits to
          be launched. Fixes bug 10456; bugfix on 0.2.4.12-alpha.
    
      o Minor bugfixes:
        - Avoid a crash bug when starting with a corrupted microdescriptor
          cache file. Fixes bug 10406; bugfix on 0.2.2.6-alpha.
        - If we fail to dump a previously cached microdescriptor to disk, avoid
          freeing duplicate data later on. Fixes bug 10423; bugfix on
          0.2.4.13-alpha. Spotted by "bobnomnom".
    
    
    Changes in version 0.2.4.19 - 2013-12-11
      The Tor 0.2.4 release series is dedicated to the memory of Aaron Swartz
      (1986-2013). Aaron worked on diverse projects including helping to guide
      Creative Commons, playing a key role in stopping SOPA/PIPA, bringing
      transparency to the U.S government's PACER documents, and contributing
      design and development for Tor and Tor2Web. Aaron was one of the latest
      martyrs in our collective fight for civil liberties and human rights,
      and his death is all the more painful because he was one of us.
    
      Tor 0.2.4.19, the first stable release in the 0.2.4 branch, features
      a new circuit handshake and link encryption that use ECC to provide
      better security and efficiency; makes relays better manage circuit
      creation requests; uses "directory guards" to reduce client enumeration
      risks; makes bridges collect and report statistics about the pluggable
      transports they support; cleans up and improves our geoip database;
      gets much closer to IPv6 support for clients, bridges, and relays; makes
      directory authorities use measured bandwidths rather than advertised
      ones when computing flags and thresholds; disables client-side DNS
      caching to reduce tracking risks; and fixes a big bug in bridge
      reachability testing. This release introduces two new design
      abstractions in the code: a new "channel" abstraction between circuits
      and or_connections to allow for implementing alternate relay-to-relay
      transports, and a new "circuitmux" abstraction storing the queue of
      circuits for a channel. The release also includes many stability,
      security, and privacy fixes.
    
      o Major features (new circuit handshake):
        - Tor now supports a new circuit extension handshake designed by Ian
          Goldberg, Douglas Stebila, and Berkant Ustaoglu. Our original
          circuit extension handshake, later called "TAP", was a bit slow
          (especially on the relay side), had a fragile security proof, and
          used weaker keys than we'd now prefer. The new circuit handshake
          uses Dan Bernstein's "curve25519" elliptic-curve Diffie-Hellman
          function, making it significantly more secure than the older
          handshake, and significantly faster. Tor can use one of two built-in
          pure-C curve25519-donna implementations by Adam Langley, or it
          can link against the "nacl" library for a tuned version if present.
    
          The built-in version is very fast for 64-bit systems when building
          with GCC. The built-in 32-bit version is still faster than the
          old TAP protocol, but using libnacl is better on most such hosts.
    
          Implements proposal 216; closes ticket 7202.
    
      o Major features (better link encryption):
        - Relays can now enable the ECDHE TLS ciphersuites when available
          and appropriate. These ciphersuites let us negotiate forward-secure
          TLS secret keys more safely and more efficiently than with our
          previous use of Diffie-Hellman modulo a 1024-bit prime. By default,
          public relays prefer the (faster) P224 group, and bridges prefer
          the (more common) P256 group; you can override this with the
          TLSECGroup option.
    
          This feature requires clients running 0.2.3.17-beta or later,
          and requires both sides to be running OpenSSL 1.0.0 or later
          with ECC support. OpenSSL 1.0.1, with the compile-time option
          "enable-ec_nistp_64_gcc_128", is highly recommended.
    
          Implements the relay side of proposal 198; closes ticket 7200.
    
        - Re-enable TLS 1.1 and 1.2 when built with OpenSSL 1.0.1e or later.
          Resolves ticket 6055. (OpenSSL before 1.0.1 didn't have TLS 1.1 or
          1.2, and OpenSSL from 1.0.1 through 1.0.1d had bugs that prevented
          renegotiation from working with TLS 1.1 or 1.2, so we had disabled
          them to solve bug 6033.)
    
      o Major features (relay performance):
        - Instead of limiting the number of queued onionskins (aka circuit
          create requests) to a fixed, hard-to-configure number, we limit
          the size of the queue based on how many we expect to be able to
          process in a given amount of time. We estimate the time it will
          take to process an onionskin based on average processing time
          of previous onionskins. Closes ticket 7291. You'll never have to
          configure MaxOnionsPending again.
        - Relays process the new "NTor" circuit-level handshake requests
          with higher priority than the old "TAP" circuit-level handshake
          requests. We still process some TAP requests to not totally starve
          0.2.3 clients when NTor becomes popular. A new consensus parameter
          "NumNTorsPerTAP" lets us tune the balance later if we need to.
          Implements ticket 9574.
    
      o Major features (client bootstrapping resilience):
        - Add a new "FallbackDir" torrc option to use when we can't use
          a directory mirror from the consensus (either because we lack a
          consensus, or because they're all down). Currently, all authorities
          are fallbacks by default, and there are no other default fallbacks,
          but that will change. This option will allow us to give clients a
          longer list of servers to try to get a consensus from when first
          connecting to the Tor network, and thereby reduce load on the
          directory authorities. Implements proposal 206, "Preconfigured
          directory sources for bootstrapping". We also removed the old
          "FallbackNetworkstatus" option, since we never got it working well
          enough to use it. Closes bug 572.
        - If we have no circuits open, use a relaxed timeout (the
          95th-percentile cutoff) until a circuit succeeds. This heuristic
          should allow Tor to succeed at building circuits even when the
          network connection drastically changes. Should help with bug 3443.
    
      o Major features (use of guards):
        - Support directory guards (proposal 207): when possible, clients now
          use their entry guards for non-anonymous directory requests. This
          can help prevent client enumeration. Note that this behavior only
          works when we have a usable consensus directory, and when options
          about what to download are more or less standard. In the future we
          should re-bootstrap from our guards, rather than re-bootstrapping
          from the preconfigured list of directory sources that ships with
          Tor. Resolves ticket 6526.
        - Raise the default time that a client keeps an entry guard from
          "1-2 months" to "2-3 months", as suggested by Tariq Elahi's WPES
          2012 paper. (We would make it even longer, but we need better client
          load balancing first.) Also, make the guard lifetime controllable
          via a new GuardLifetime torrc option and a GuardLifetime consensus
          parameter. Start of a fix for bug 8240; bugfix on 0.1.1.11-alpha.
    
      o Major features (bridges with pluggable transports):
        - Bridges now report the pluggable transports they support to the
          bridge authority, so it can pass the supported transports on to
          bridgedb and/or eventually do reachability testing. Implements
          ticket 3589.
        - Automatically forward the TCP ports of pluggable transport
          proxies using tor-fw-helper if PortForwarding is enabled. Implements
          ticket 4567.
    
      o Major features (geoip database):
        - Maxmind began labelling Tor relays as being in country "A1",
          which breaks by-country node selection inside Tor. Now we use a
          script to replace "A1" ("Anonymous Proxy") entries in our geoip
          file with real country codes. This script fixes about 90% of "A1"
          entries automatically and uses manual country code assignments to
          fix the remaining 10%. See src/config/README.geoip for details.
          Fixes bug 6266.
        - Add GeoIP database for IPv6 addresses. The new config option
          is GeoIPv6File.
        - Update to the October 2 2013 Maxmind GeoLite Country database.
    
      o Major features (IPv6):
        - Clients who set "ClientUseIPv6 1" may connect to entry nodes over
          IPv6. Set "ClientPreferIPv6ORPort 1" to make this even more likely
          to happen. Implements ticket 5535.
        - All kind of relays, not just bridges, can now advertise an IPv6
          OR port. Implements ticket 6362.
        - Relays can now exit to IPv6 addresses: make sure that you have IPv6
          connectivity, then set the IPv6Exit flag to 1. Also make sure your
          exit policy reads as you would like: the address * applies to all
          address families, whereas *4 is IPv4 address only, and *6 is IPv6
          addresses only. On the client side, you'll need to wait for enough
          exits to support IPv6, apply the "IPv6Traffic" flag to a SocksPort,
          and use Socks5. Closes ticket 5547, implements proposal 117 as
          revised in proposal 208.
        - Bridge authorities now accept IPv6 bridge addresses and include
          them in network status documents. Implements ticket 5534.
        - Directory authorities vote on IPv6 OR ports. Implements ticket 6363.
    
      o Major features (directory authorities):
        - Directory authorities now prefer using measured bandwidths to
          advertised ones when computing flags and thresholds. Resolves
          ticket 8273.
        - Directory authorities that vote measured bandwidths about more
          than a threshold number of relays now treat relays with
          unmeasured bandwidths as having bandwidth 0 when computing their
          flags. Resolves ticket 8435.
        - Directory authorities now support a new consensus method (17)
          where they cap the published bandwidth of relays for which
          insufficient bandwidth measurements exist. Fixes part of bug 2286.
        - Directory authorities that set "DisableV2DirectoryInfo_ 1" no longer
          serve any v2 directory information. Now we can test disabling the
          old deprecated v2 directory format, and see whether doing so has
          any effect on network load. Begins to fix bug 6783.
    
      o Major features (build and portability):
        - Switch to a nonrecursive Makefile structure. Now instead of each
          Makefile.am invoking other Makefile.am's, there is a master
          Makefile.am that includes the others. This change makes our build
          process slightly more maintainable, and improves parallelism for
          building with make -j. Original patch by Stewart Smith; various
          fixes by Jim Meyering.
        - Where available, we now use automake's "silent" make rules by
          default, so that warnings are easier to spot. You can get the old
          behavior with "make V=1". Patch by Stewart Smith for ticket 6522.
        - Resume building correctly with MSVC and Makefile.nmake. This patch
          resolves numerous bugs and fixes reported by ultramage, including
          7305, 7308, 7309, 7310, 7312, 7313, 7315, 7316, and 7669.
    
      o Security features:
        - Switch to a completely time-invariant approach for picking nodes
          weighted by bandwidth. Our old approach would run through the
          part of the loop after it had made its choice slightly slower
          than it ran through the part of the loop before it had made its
          choice. Addresses ticket 6538.
        - Disable the use of Guard nodes when in Tor2WebMode. Guard usage
          by tor2web clients allows hidden services to identify tor2web
          clients through their repeated selection of the same rendezvous
          and introduction point circuit endpoints (their guards). Resolves
          ticket 6888.
    
      o Major bugfixes (relay denial of service):
        - When we have too much memory queued in circuits (according to a new
          MaxMemInCellQueues option), close the circuits that have the oldest
          queued cells, on the theory that those are most responsible for
          us running low on memory. This prevents us from running out of
          memory as a relay if circuits fill up faster than they can be
          drained. Fixes bugs 9063 and 9093; bugfix on the 54th commit of
          Tor. This bug is a further fix beyond bug 6252, whose fix was
          merged into 0.2.3.21-rc.
        - Reject bogus create and relay cells with 0 circuit ID or 0 stream
          ID: these could be used to create unexpected streams and circuits
          which would count as "present" to some parts of Tor but "absent"
          to others, leading to zombie circuits and streams or to a bandwidth
          denial-of-service. Fixes bug 7889; bugfix on every released version
          of Tor. Reported by "oftc_must_be_destroyed".
        - Avoid a bug where our response to TLS renegotiation under certain
          network conditions could lead to a busy-loop, with 100% CPU
          consumption. Fixes bug 5650; bugfix on 0.2.0.16-alpha.
    
      o Major bugfixes (asserts, crashes, leaks):
        - Prevent the get_freelists() function from running off the end of
          the list of freelists if it somehow gets an unrecognized
          allocation. Fixes bug 8844; bugfix on 0.2.0.16-alpha. Reported by
          eugenis.
        - Avoid a memory leak where we would leak a consensus body when we
          find that a consensus which we couldn't previously verify due to
          missing certificates is now verifiable. Fixes bug 8719; bugfix
          on 0.2.0.10-alpha.
        - If we are unable to save a microdescriptor to the journal, do not
          drop it from memory and then reattempt downloading it. Fixes bug
          9645; bugfix on 0.2.2.6-alpha.
        - Fix an assertion failure that would occur when disabling the
          ORPort setting on a running Tor process while accounting was
          enabled. Fixes bug 6979; bugfix on 0.2.2.18-alpha.
        - Avoid an assertion failure on OpenBSD (and perhaps other BSDs)
          when an exit connection with optimistic data succeeds immediately
          rather than returning EINPROGRESS. Fixes bug 9017; bugfix on
          0.2.3.1-alpha.
        - Fix a memory leak that would occur whenever a configuration
          option changed. Fixes bug 8718; bugfix on 0.2.3.3-alpha.
    
      o Major bugfixes (relay rate limiting):
        - When a TLS write is partially successful but incomplete, remember
          that the flushed part has been flushed, and notice that bytes were
          actually written. Reported and fixed pseudonymously. Fixes bug 7708;
          bugfix on Tor 0.1.0.5-rc.
        - Raise the default BandwidthRate/BandwidthBurst values from 5MB/10MB
          to 1GB/1GB. The previous defaults were intended to be "basically
          infinite", but it turns out they're now limiting our 100mbit+
          relays and bridges. Fixes bug 6605; bugfix on 0.2.0.10-alpha (the
          last time we raised it).
        - No longer stop reading or writing on cpuworker connections when
          our rate limiting buckets go empty. Now we should handle circuit
          handshake requests more promptly. Resolves bug 9731.
    
      o Major bugfixes (client-side privacy):
        - When we mark a circuit as unusable for new circuits, have it
          continue to be unusable for new circuits even if MaxCircuitDirtiness
          is increased too much at the wrong time, or the system clock jumps
          backwards. Fixes bug 6174; bugfix on 0.0.2pre26.
        - If ClientDNSRejectInternalAddresses ("do not believe DNS queries
          which have resolved to internal addresses") is set, apply that
          rule to IPv6 as well. Fixes bug 8475; bugfix on 0.2.0.7-alpha.
        - When an exit relay rejects a stream with reason "exit policy", but
          we only know an exit policy summary (e.g. from the microdesc
          consensus) for it, do not mark the relay as useless for all exiting.
          Instead, mark just the circuit as unsuitable for that particular
          address. Fixes part of bug 7582; bugfix on 0.2.3.2-alpha.
    
      o Major bugfixes (stream isolation):
        - Allow applications to get proper stream isolation with
          IsolateSOCKSAuth. Many SOCKS5 clients that want to offer
          username/password authentication also offer "no authentication". Tor
          had previously preferred "no authentication", so the applications
          never actually sent Tor their auth details. Now Tor selects
          username/password authentication if it's offered. You can disable
          this behavior on a per-SOCKSPort basis via PreferSOCKSNoAuth. Fixes
          bug 8117; bugfix on 0.2.3.3-alpha.
        - Follow the socks5 protocol when offering username/password
          authentication. The fix for bug 8117 exposed this bug, and it
          turns out real-world applications like Pidgin do care. Bugfix on
          0.2.3.2-alpha; fixes bug 8879.
    
      o Major bugfixes (client circuit building):
        - Alter circuit build timeout measurement to start at the point
          where we begin the CREATE/CREATE_FAST step (as opposed to circuit
          initialization). This should make our timeout measurements more
          uniform. Previously, we were sometimes including ORconn setup time
          in our circuit build time measurements. Should resolve bug 3443.
        - If the circuit build timeout logic is disabled (via the consensus,
          or because we are an authority), then don't build testing circuits.
          Fixes bug 9657; bugfix on 0.2.2.14-alpha.
    
      o Major bugfixes (client-side DNS):
        - Turn off the client-side DNS cache by default. Updating and using
          the DNS cache is now configurable on a per-client-port
          level. SOCKSPort, DNSPort, etc lines may now contain
          {No,}Cache{IPv4,IPv6,}DNS lines to indicate that we shouldn't
          cache these types of DNS answers when we receive them from an
          exit node in response to an application request on this port, and
          {No,}UseCached{IPv4,IPv6,DNS} lines to indicate that if we have
          cached DNS answers of these types, we shouldn't use them. It's
          potentially risky to use cached DNS answers at the client, since
          doing so can indicate to one exit what answers we've gotten
          for DNS lookups in the past. With IPv6, this becomes especially
          problematic. Using cached DNS answers for requests on the same
          circuit would present less linkability risk, since all traffic
          on a circuit is already linkable, but it would also provide
          little performance benefit: the exit node caches DNS replies
          too. Implements a simplified version of Proposal 205. Implements
          ticket 7570.
    
      o Major bugfixes (hidden service privacy):
        - Limit hidden service descriptors to at most ten introduction
          points, to slow one kind of guard enumeration. Fixes bug 9002;
          bugfix on 0.1.1.11-alpha.
    
      o Major bugfixes (directory fetching):
        - If the time to download the next old-style networkstatus is in
          the future, do not decline to consider whether to download the
          next microdescriptor networkstatus. Fixes bug 9564; bugfix on
          0.2.3.14-alpha.
        - We used to always request authority certificates by identity digest,
          meaning we'd get the newest one even when we wanted one with a
          different signing key. Then we would complain about being given
          a certificate we already had, and never get the one we really
          wanted. Now we use the "fp-sk/" resource as well as the "fp/"
          resource to request the one we want. Fixes bug 5595; bugfix on
          0.2.0.8-alpha.
    
      o Major bugfixes (bridge reachability):
        - Bridges now send AUTH_CHALLENGE cells during their v3 handshakes;
          previously they did not, which prevented them from receiving
          successful connections from relays for self-test or bandwidth
          testing. Also, when a relay is extending a circuit to a bridge,
          it needs to send a NETINFO cell, even when the bridge hasn't sent
          an AUTH_CHALLENGE cell. Fixes bug 9546; bugfix on 0.2.3.6-alpha.
    
      o Major bugfixes (control interface):
        - When receiving a new configuration file via the control port's
          LOADCONF command, do not treat the defaults file as absent.
          Fixes bug 9122; bugfix on 0.2.3.9-alpha.
    
      o Major bugfixes (directory authorities):
        - Stop marking every relay as having been down for one hour every
          time we restart a directory authority. These artificial downtimes
          were messing with our Stable and Guard flag calculations. Fixes
          bug 8218 (introduced by the fix for 1035). Bugfix on 0.2.2.23-alpha.
        - When computing directory thresholds, ignore any rejected-as-sybil
          nodes during the computation so that they can't influence Fast,
          Guard, etc. (We should have done this for proposal 109.) Fixes
          bug 8146.
        - When marking a node as a likely sybil, reset its uptime metrics
          to zero, so that it cannot time towards getting marked as Guard,
          Stable, or HSDir. (We should have done this for proposal 109.) Fixes
          bug 8147.
        - Fix a bug in the voting algorithm that could yield incorrect results
          when a non-naming authority declared too many flags. Fixes bug 9200;
          bugfix on 0.2.0.3-alpha.
    
      o Internal abstraction features:
        - Introduce new channel_t abstraction between circuits and
          or_connection_t to allow for implementing alternate OR-to-OR
          transports. A channel_t is an abstract object which can either be a
          cell-bearing channel, which is responsible for authenticating and
          handshaking with the remote OR and transmitting cells to and from
          it, or a listening channel, which spawns new cell-bearing channels
          at the request of remote ORs. Implements part of ticket 6465.
        - Make a channel_tls_t subclass of channel_t, adapting it to the
          existing or_connection_t code. The V2/V3 protocol handshaking
          code which formerly resided in command.c has been moved below the
          channel_t abstraction layer and may be found in channeltls.c now.
          Implements the rest of ticket 6465.
        - Introduce new circuitmux_t storing the queue of circuits for
          a channel; this encapsulates and abstracts the queue logic and
          circuit selection policy, and allows the latter to be overridden
          easily by switching out a policy object. The existing EWMA behavior
          is now implemented as a circuitmux_policy_t. Resolves ticket 6816.
    
      o New build requirements:
        - Tor now requires OpenSSL 0.9.8 or later. OpenSSL 1.0.0 or later is
          strongly recommended.
        - Tor maintainers now require Automake version 1.9 or later to build
          Tor from the Git repository. (Automake is not required when building
          from a source distribution.)
    
      o Minor features (protocol):
        - No longer include the "opt" prefix when generating routerinfos
          or v2 directories: it has been needless since Tor 0.1.2. Closes
          ticket 5124.
        - Reject EXTEND cells sent to nonexistent streams. According to the
          spec, an EXTEND cell sent to _any_ nonzero stream ID is invalid, but
          we were only checking for stream IDs that were currently in use.
          Found while hunting for more instances of bug 6271. Bugfix on
          0.0.2pre8, which introduced incremental circuit construction.
        - Tor relays and clients now support a better CREATE/EXTEND cell
          format, allowing the sender to specify multiple address, identity,
          and handshake types. Implements Robert Ransom's proposal 200;
          closes ticket 7199.
        - Reject as invalid most directory objects containing a NUL.
          Belt-and-suspender fix for bug 8037.
    
      o Minor features (security):
        - Clear keys and key-derived material left on the stack in
          rendservice.c and rendclient.c. Check return value of
          crypto_pk_write_private_key_to_string() in rend_service_load_keys().
          These fixes should make us more forward-secure against cold-boot
          attacks and the like. Fixes bug 2385.
        - Use our own weak RNG when we need a weak RNG. Windows's rand() and
          Irix's random() only return 15 bits; Solaris's random() returns more
          bits but its RAND_MAX says it only returns 15, and so on. Motivated
          by the fix for bug 7801; bugfix on 0.2.2.20-alpha.
    
      o Minor features (control protocol):
        - Add a "GETINFO signal/names" control port command. Implements
          ticket 3842.
        - Provide default values for all options via "GETINFO config/defaults".
          Implements ticket 4971.
        - Allow an optional $ before the node identity digest in the
          controller command GETINFO ns/id/<identity>, for consistency with
          md/id/<identity> and desc/id/<identity>. Resolves ticket 7059.
        - Add CACHED keyword to ADDRMAP events in the control protocol
          to indicate whether a DNS result will be cached or not. Resolves
          ticket 8596.
        - Generate bootstrapping status update events correctly when fetching
          microdescriptors. Fixes bug 9927.
    
      o Minor features (path selection):
        - When deciding whether we have enough descriptors to build circuits,
          instead of looking at raw relay counts, look at which fraction
          of (bandwidth-weighted) paths we're able to build. This approach
          keeps clients from building circuits if their paths are likely to
          stand out statistically. The default fraction of paths needed is
          taken from the consensus directory; you can override it with the
          new PathsNeededToBuildCircuits option. Fixes ticket 5956.
        - When any country code is listed in ExcludeNodes or ExcludeExitNodes,
          and we have GeoIP information, also exclude all nodes with unknown
          countries "??" and "A1". This behavior is controlled by the
          new GeoIPExcludeUnknown option: you can make such nodes always
          excluded with "GeoIPExcludeUnknown 1", and disable the feature
          with "GeoIPExcludeUnknown 0". Setting "GeoIPExcludeUnknown auto"
          gets you the default behavior. Implements feature 7706.
    
      o Minor features (hidden services):
        - Improve circuit build timeout handling for hidden services.
          In particular: adjust build timeouts more accurately depending
          upon the number of hop-RTTs that a particular circuit type
          undergoes. Additionally, launch intro circuits in parallel
          if they timeout, and take the first one to reply as valid.
        - The Tor client now ignores sub-domain components of a .onion
          address. This change makes HTTP "virtual" hosting
          possible: http://foo.aaaaaaaaaaaaaaaa.onion/ and
          http://bar.aaaaaaaaaaaaaaaa.onion/ can be two different websites
          hosted on the same hidden service. Implements proposal 204.
        - Enable Tor to read configuration, state, and key information from
          a FIFO. Previously Tor would only read from files with a positive
          stat.st_size. Code from meejah; fixes bug 6044.
    
      o Minor features (clients):
        - Teach bridge-using clients to avoid 0.2.2.x bridges when making
          microdescriptor-related dir requests, and only fall back to normal
          descriptors if none of their bridges can handle microdescriptors
          (as opposed to the fix in ticket 4013, which caused them to fall
          back to normal descriptors if *any* of their bridges preferred
          them). Resolves ticket 4994.
        - Tweak tor-fw-helper to accept an arbitrary amount of arbitrary
          TCP ports to forward. In the past it only accepted two ports:
          the ORPort and the DirPort.
    
      o Minor features (protecting client timestamps):
        - Clients no longer send timestamps in their NETINFO cells. These were
          not used for anything, and they provided one small way for clients
          to be distinguished from each other as they moved from network to
          network or behind NAT. Implements part of proposal 222.
        - Clients now round timestamps in INTRODUCE cells down to the nearest
          10 minutes. If a new Support022HiddenServices option is set to 0, or
          if it's set to "auto" and the feature is disabled in the consensus,
          the timestamp is sent as 0 instead. Implements part of proposal 222.
        - Stop sending timestamps in AUTHENTICATE cells. This is not such
          a big deal from a security point of view, but it achieves no actual
          good purpose, and isn't needed. Implements part of proposal 222.
        - Reduce down accuracy of timestamps in hidden service descriptors.
          Implements part of proposal 222.
    
      o Minor features (bridges):
        - Make bridge relays check once a minute for whether their IP
          address has changed, rather than only every 15 minutes. Resolves
          bugs 1913 and 1992.
        - Bridge statistics now count bridge clients connecting over IPv6:
          bridge statistics files now list "bridge-ip-versions" and
          extra-info documents list "geoip6-db-digest". The control protocol
          "CLIENTS_SEEN" and "ip-to-country" queries now support IPv6. Initial
          implementation by "shkoo", addressing ticket 5055.
        - Add a new torrc option "ServerTransportListenAddr" to let bridge
          operators select the address where their pluggable transports will
          listen for connections. Resolves ticket 7013.
        - Randomize the lifetime of our SSL link certificate, so censors can't
          use the static value for filtering Tor flows. Resolves ticket 8443;
          related to ticket 4014 which was included in 0.2.2.33.
    
      o Minor features (relays):
        - Option OutboundBindAddress can be specified multiple times and
          accepts IPv6 addresses. Resolves ticket 6876.
    
      o Minor features (IPv6, client side):
        - AutomapHostsOnResolve now supports IPv6 addresses. By default, we
          prefer to hand out virtual IPv6 addresses, since there are more of
          them and we can't run out. To override this behavior and make IPv4
          addresses preferred, set NoPreferIPv6Automap on whatever SOCKSPort
          or DNSPort you're using for resolving. Implements ticket 7571.
        - AutomapHostsOnResolve responses are now randomized, to avoid
          annoying situations where Tor is restarted and applications
          connect to the wrong addresses.
        - Never try more than 1000 times to pick a new virtual address when
          AutomapHostsOnResolve is set. That's good enough so long as we
          aren't close to handing out our entire virtual address space;
          if you're getting there, it's best to switch to IPv6 virtual
          addresses anyway.
    
      o Minor features (IPv6, relay/authority side):
        - New config option "AuthDirHasIPv6Connectivity 1" that directory
          authorities should set if they have IPv6 connectivity and want to
          do reachability tests for IPv6 relays. Implements feature 5974.
        - A relay with an IPv6 OR port now sends that address in NETINFO
          cells (in addition to its other address). Implements ticket 6364.
    
      o Minor features (directory authorities):
        - Directory authorities no long accept descriptors for any version of
          Tor before 0.2.2.35, or for any 0.2.3 release before 0.2.3.10-alpha.
          These versions are insecure, unsupported, or both. Implements
          ticket 6789.
        - When directory authorities are computing thresholds for flags,
          never let the threshold for the Fast flag fall below 4096
          bytes. Also, do not consider nodes with extremely low bandwidths
          when deciding thresholds for various directory flags. This change
          should raise our threshold for Fast relays, possibly in turn
          improving overall network performance; see ticket 1854. Resolves
          ticket 8145.
        - Directory authorities now include inside each vote a statement of
          the performance thresholds they used when assigning flags.
          Implements ticket 8151.
        - Add an "ignoring-advertised-bws" boolean to the flag-threshold lines
          in directory authority votes to describe whether they have enough
          measured bandwidths to ignore advertised (relay descriptor)
          bandwidth claims. Resolves ticket 8711.
    
      o Minor features (path bias detection):
        - Path Use Bias: Perform separate accounting for successful circuit
          use. Keep separate statistics on stream attempt rates versus stream
          success rates for each guard. Provide configurable thresholds to
          determine when to emit log messages or disable use of guards that
          fail too many stream attempts. Resolves ticket 7802.
        - Create three levels of Path Bias log messages, as opposed to just
          two. These are configurable via consensus as well as via the torrc
          options PathBiasNoticeRate, PathBiasWarnRate, PathBiasExtremeRate.
          The default values are 0.70, 0.50, and 0.30 respectively.
        - Separate the log message levels from the decision to drop guards,
          which also is available via torrc option PathBiasDropGuards.
          PathBiasDropGuards still defaults to 0 (off).
        - Deprecate PathBiasDisableRate in favor of PathBiasDropGuards
          in combination with PathBiasExtremeRate.
        - Increase the default values for PathBiasScaleThreshold and
          PathBiasCircThreshold from (200, 20) to (300, 150).
        - Add in circuit usage accounting to path bias. If we try to use a
          built circuit but fail for any reason, it counts as path bias.
          Certain classes of circuits where the adversary gets to pick your
          destination node are exempt from this accounting. Usage accounting
          can be specifically disabled via consensus parameter or torrc.
        - Convert all internal path bias state to double-precision floating
          point, to avoid roundoff error and other issues.
        - Only record path bias information for circuits that have completed
          *two* hops. Assuming end-to-end tagging is the attack vector, this
          makes us more resilient to ambient circuit failure without any
          detection capability loss.
    
      o Minor features (build):
        - Tor now builds correctly on Bitrig, an OpenBSD fork. Patch from
          dhill. Resolves ticket 6982.
        - Compile on win64 using mingw64. Fixes bug 7260; patches from
          "yayooo".
        - Work correctly on Unix systems where EAGAIN and EWOULDBLOCK are
          separate error codes; or at least, don't break for that reason.
          Fixes bug 7935. Reported by "oftc_must_be_destroyed".
    
      o Build improvements (autotools):
        - Warn if building on a platform with an unsigned time_t: there
          are too many places where Tor currently assumes that time_t can
          hold negative values. We'd like to fix them all, but probably
          some will remain.
        - Do not report status verbosely from autogen.sh unless the -v flag
          is specified. Fixes issue 4664. Patch from Onizuka.
        - Detect and reject attempts to build Tor with threading support
          when OpenSSL has been compiled without threading support.
          Fixes bug 6673.
        - Try to detect if we are ever building on a platform where
          memset(...,0,...) does not set the value of a double to 0.0. Such
          platforms are permitted by the C standard, though in practice
          they're pretty rare (since IEEE 754 is nigh-ubiquitous). We don't
          currently support them, but it's better to detect them and fail
          than to perform erroneously.
        - We no longer warn so much when generating manpages from their
          asciidoc source.
        - Use Ville Laurikari's implementation of AX_CHECK_SIGN() to determine
          the signs of types during autoconf. This is better than our old
          approach, which didn't work when cross-compiling.
    
      o Minor features (log messages, warnings):
        - Detect when we're running with a version of OpenSSL other than the
          one we compiled with. This conflict has occasionally given people
          hard-to-track-down errors.
        - Warn users who run hidden services on a Tor client with
          UseEntryGuards disabled that their hidden services will be
          vulnerable to http://freehaven.net/anonbib/#hs-attack06 (the
          attack which motivated Tor to support entry guards in the first
          place). Resolves ticket 6889.
        - Warn when we are binding low ports when hibernation is enabled;
          previously we had warned when we were _advertising_ low ports with
          hibernation enabled. Fixes bug 7285; bugfix on 0.2.3.9-alpha.
        - Issue a warning when running with the bufferevents backend enabled.
          It's still not stable, and people should know that they're likely
          to hit unexpected problems. Closes ticket 9147.
    
      o Minor features (log messages, notices):
        - Refactor resolve_my_address() so it returns the method by which we
          decided our public IP address (explicitly configured, resolved from
          explicit hostname, guessed from interfaces, learned by gethostname).
          Now we can provide more helpful log messages when a relay guesses
          its IP address incorrectly (e.g. due to unexpected lines in
          /etc/hosts). Resolves ticket 2267.
        - Track how many "TAP" and "NTor" circuit handshake requests we get,
          and how many we complete, and log it every hour to help relay
          operators follow trends in network load. Addresses ticket 9658.
    
      o Minor features (log messages, diagnostics):
        - If we fail to free a microdescriptor because of bug 7164, log
          the filename and line number from which we tried to free it.
        - We compute the overhead from passing onionskins back and forth to
          cpuworkers, and report it when dumping statistics in response to
          SIGUSR1. Supports ticket 7291.
        - Add another diagnostic to the heartbeat message: track and log
          overhead that TLS is adding to the data we write. If this is
          high, we are sending too little data to SSL_write at a time.
          Diagnostic for bug 7707.
        - Log packaged cell fullness as part of the heartbeat message.
          Diagnosis to try to determine the extent of bug 7743.
        - Add more detail to a log message about relaxed timeouts, to help
          track bug 7799.
        - When learning a fingerprint for a bridge, log its corresponding
          transport type. Implements ticket 7896.
        - Warn more aggressively when flushing microdescriptors to a
          microdescriptor cache fails, in an attempt to mitigate bug 8031,
          or at least make it more diagnosable.
        - Improve the log message when "Bug/attack: unexpected sendme cell
          from client" occurs, to help us track bug 8093.
        - Improve debugging output to help track down bug 8185 ("Bug:
          outgoing relay cell has n_chan==NULL. Dropping.")
    
      o Minor features (log messages, quieter bootstrapping):
        - Log fewer lines at level "notice" about our OpenSSL and Libevent
          versions and capabilities when everything is going right. Resolves
          part of ticket 6736.
        - Omit the first heartbeat log message, because it never has anything
          useful to say, and it clutters up the bootstrapping messages.
          Resolves ticket 6758.
        - Don't log about reloading the microdescriptor cache at startup. Our
          bootstrap warnings are supposed to tell the user when there's a
          problem, and our bootstrap notices say when there isn't. Resolves
          ticket 6759; bugfix on 0.2.2.6-alpha.
        - Don't log "I learned some more directory information" when we're
          reading cached directory information. Reserve it for when new
          directory information arrives in response to a fetch. Resolves
          ticket 6760.
        - Don't complain about bootstrapping problems while hibernating.
          These complaints reflect a general code problem, but not one
          with any problematic effects (no connections are actually
          opened). Fixes part of bug 7302; bugfix on 0.2.3.2-alpha.
    
      o Minor features (testing):
        - In our testsuite, create temporary directories with a bit more
          entropy in their name to make name collisions less likely. Fixes
          bug 8638.
        - Add benchmarks for DH (1024-bit multiplicative group) and ECDH
          (P-256) Diffie-Hellman handshakes to src/or/bench.
        - Add benchmark functions to test onion handshake performance.
    
      o Renamed options:
        - The DirServer option is now DirAuthority, for consistency with
          current naming patterns. You can still use the old DirServer form.
    
      o Minor bugfixes (protocol):
        - Fix the handling of a TRUNCATE cell when it arrives while the
          circuit extension is in progress. Fixes bug 7947; bugfix on 0.0.7.1.
        - When a Tor client gets a "truncated" relay cell, the first byte of
          its payload specifies why the circuit was truncated. We were
          ignoring this 'reason' byte when tearing down the circuit, resulting
          in the controller not being told why the circuit closed. Now we
          pass the reason from the truncated cell to the controller. Bugfix
          on 0.1.2.3-alpha; fixes bug 7039.
        - Fix a misframing issue when reading the version numbers in a
          VERSIONS cell. Previously we would recognize [00 01 00 02] as
          'version 1, version 2, and version 0x100', when it should have
          only included versions 1 and 2. Fixes bug 8059; bugfix on
          0.2.0.10-alpha. Reported pseudonymously.
        - Make the format and order of STREAM events for DNS lookups
          consistent among the various ways to launch DNS lookups. Fixes
          bug 8203; bugfix on 0.2.0.24-rc. Patch by "Desoxy".
    
      o Minor bugfixes (syscalls and disk interaction):
        - Always check the return values of functions fcntl() and
          setsockopt(). We don't believe these are ever actually failing in
          practice, but better safe than sorry. Also, checking these return
          values should please analysis tools like Coverity. Patch from
          'flupzor'. Fixes bug 8206; bugfix on all versions of Tor.
        - Avoid double-closing the listener socket in our socketpair()
          replacement (used on Windows) in the case where the addresses on
          our opened sockets don't match what we expected. Fixes bug 9400;
          bugfix on 0.0.2pre7. Found by Coverity.
        - Correctly store microdescriptors and extrainfo descriptors that
          include an internal NUL byte. Fixes bug 8037; bugfix on
          0.2.0.1-alpha. Bug reported by "cypherpunks".
        - If for some reason we fail to write a microdescriptor while
          rebuilding the cache, do not let the annotations from that
          microdescriptor linger in the cache file, and do not let the
          microdescriptor stay recorded as present in its old location.
          Fixes bug 9047; bugfix on 0.2.2.6-alpha.
        - Use direct writes rather than stdio when building microdescriptor
          caches, in an attempt to mitigate bug 8031, or at least make it
          less common.
    
      o Minor fixes (config options):
        - Warn and fail if a server is configured not to advertise any
          ORPorts at all. (We need *something* to put in our descriptor,
          or we just won't work.)
        - Behave correctly when the user disables LearnCircuitBuildTimeout
          but doesn't tell us what they would like the timeout to be. Fixes
          bug 6304; bugfix on 0.2.2.14-alpha.
        - Rename the (internal-use-only) UsingTestingNetworkDefaults option
          to start with a triple-underscore so the controller won't touch it.
          Patch by Meejah. Fixes bug 3155. Bugfix on 0.2.2.23-alpha.
        - Rename the (testing-use-only) _UseFilteringSSLBufferevents option
          so it doesn't start with _. Fixes bug 3155. Bugfix on 0.2.3.1-alpha.
        - When autodetecting the number of CPUs, use the number of available
          CPUs in preference to the number of configured CPUs. Inform the
          user if this reduces the number of available CPUs. Fixes bug 8002;
          bugfix on 0.2.3.1-alpha.
        - Command-line option "--version" implies "--quiet". Fixes bug 6997.
        - Make it an error when you set EntryNodes but disable UseGuardNodes,
          since it will (surprisingly to some users) ignore EntryNodes. Fixes
          bug 8180; bugfix on 0.2.3.11-alpha.
        - Avoid overflows when the user sets MaxCircuitDirtiness to a
          ridiculously high value, by imposing a (ridiculously high) 30-day
          maximum on MaxCircuitDirtiness.
    
      o Minor bugfixes (control protocol):
        - Stop sending a stray "(null)" in some cases for the server status
          "EXTERNAL_ADDRESS" controller event. Resolves bug 8200; bugfix
          on 0.1.2.6-alpha.
        - The ADDRMAP command can no longer generate an ill-formed error
          code on a failed MAPADDRESS. It now says "internal" rather than
          an English sentence fragment with spaces in the middle. Bugfix on
          Tor 0.2.0.19-alpha.
    
      o Minor bugfixes (clients / edges):
        - When we receive a RELAY_END cell with the reason DONE, or with no
          reason, before receiving a RELAY_CONNECTED cell, report the SOCKS
          status as "connection refused". Previously we reported these cases
          as success but then immediately closed the connection. Fixes bug
          7902; bugfix on 0.1.0.1-rc. Reported by "oftc_must_be_destroyed".
        - If the guard we choose first doesn't answer, we would try the
          second guard, but once we connected to the second guard we would
          abandon it and retry the first one, slowing down bootstrapping.
          The fix is to treat all our initially chosen guards as acceptable
          to use. Fixes bug 9946; bugfix on 0.1.1.11-alpha.
        - When choosing which stream on a formerly stalled circuit to wake
          first, make better use of the platform's weak RNG. Previously,
          we had been using the % ("modulo") operator to try to generate a
          1/N chance of picking each stream, but this behaves badly with
          many platforms' choice of weak RNG. Fixes bug 7801; bugfix on
          0.2.2.20-alpha.
    
      o Minor bugfixes (path bias detection):
        - If the state file's path bias counts are invalid (presumably from a
          buggy Tor prior to 0.2.4.10-alpha), make them correct. Also add
          additional checks and log messages to the scaling of Path Bias
          counts, in case there still are remaining issues with scaling.
          Should help resolve bug 8235.
        - Prevent rounding error in path bias counts when scaling
          them down, and use the correct scale factor default. Also demote
          some path bias related log messages down a level and make others
          less scary sounding. Fixes bug 6647. Bugfix on 0.2.3.17-beta.
        - Remove a source of rounding error during path bias count scaling;
          don't count cannibalized circuits as used for path bias until we
          actually try to use them; and fix a circuit_package_relay_cell()
          warning message about n_chan==NULL. Fixes bug 7802.
        - Paste the description for PathBias parameters from the man
          page into or.h, so the code documents them too. Fixes bug 7982;
          bugfix on 0.2.3.17-beta.
    
      o Minor bugfixes (relays):
        - Stop trying to resolve our hostname so often (e.g. every time we
          think about doing a directory fetch). Now we reuse the cached
          answer in some cases. Fixes bugs 1992 (bugfix on 0.2.0.20-rc)
          and 2410 (bugfix on 0.1.2.2-alpha).
        - When examining the list of network interfaces to find our address,
          do not consider non-running or disabled network interfaces. Fixes
          bug 9904; bugfix on 0.2.3.11-alpha. Patch from "hantwister".
    
      o Minor bugfixes (blocking resistance):
        - Only disable TLS session ticket support when running as a TLS
          server. Now clients will blend better with regular Firefox
          connections. Fixes bug 7189; bugfix on Tor 0.2.3.23-rc.
    
      o Minor bugfixes (IPv6):
        - Use square brackets around IPv6 addresses in numerous places
          that needed them, including log messages, HTTPS CONNECT proxy
          requests, TransportProxy statefile entries, and pluggable transport
          extra-info lines. Fixes bug 7011; patch by David Fifield.
    
      o Minor bugfixes (directory authorities):
        - Reject consensus votes with more than 64 known-flags. We aren't even
          close to that limit yet, and our code doesn't handle it correctly.
          Fixes bug 6833; bugfix on 0.2.0.1-alpha.
        - Correctly handle votes with more than 31 flags. Fixes bug 6853;
          bugfix on 0.2.0.3-alpha.
    
      o Minor bugfixes (memory leaks):
        - Avoid leaking memory if we fail to compute a consensus signature
          or we generate a consensus we can't parse. Bugfix on 0.2.0.5-alpha.
        - Fix a memory leak when receiving headers from an HTTPS proxy. Bugfix
          on 0.2.1.1-alpha; fixes bug 7816.
        - Fix a memory leak during safe-cookie controller authentication.
          Bugfix on 0.2.3.13-alpha; fixes bug 7816.
        - Free some more still-in-use memory at exit, to make hunting for
          memory leaks easier. Resolves bug 7029.
    
      o Minor bugfixes (code correctness):
        - Increase the width of the field used to remember a connection's
          link protocol version to two bytes. Harmless for now, since the
          only currently recognized versions are one byte long. Reported
          pseudonymously. Fixes bug 8062; bugfix on 0.2.0.10-alpha.
        - Fix a crash when debugging unit tests on Windows: deallocate a
          shared library with FreeLibrary, not CloseHandle. Fixes bug 7306;
          bugfix on 0.2.2.17-alpha. Reported by "ultramage".
        - When detecting the largest possible file descriptor (in order to
          close all file descriptors when launching a new program), actually
          use _SC_OPEN_MAX. The old code for doing this was very, very broken.
          Fixes bug 8209; bugfix on 0.2.3.1-alpha. Found by Coverity; this
          is CID 743383.
        - Avoid a crash if we fail to generate an extrainfo descriptor.
          Fixes bug 8208; bugfix on 0.2.3.16-alpha. Found by Coverity;
          this is CID 718634.
        - Avoid an off-by-one error when checking buffer boundaries when
          formatting the exit status of a pluggable transport helper.
          This is probably not an exploitable bug, but better safe than
          sorry. Fixes bug 9928; bugfix on 0.2.3.18-rc. Bug found by
          Pedro Ribeiro.
        - Get rid of a couple of harmless clang warnings, where we compared
          enums to ints. These warnings are newly introduced in clang 3.2.
    
      o Minor bugfixes (code cleanliness):
        - Avoid use of reserved identifiers in our C code. The C standard
          doesn't like us declaring anything that starts with an
          underscore, so let's knock it off before we get in trouble. Fix
          for bug 1031; bugfix on the first Tor commit.
        - Fix round_to_power_of_2() so it doesn't invoke undefined behavior
          with large values. This situation was untriggered, but nevertheless
          incorrect. Fixes bug 6831; bugfix on 0.2.0.1-alpha.
        - Fix an impossible buffer overrun in the AES unit tests. Fixes
          bug 8845; bugfix on 0.2.0.7-alpha. Found by eugenis.
        - Fix handling of rendezvous client authorization types over 8.
          Fixes bug 6861; bugfix on 0.2.1.5-alpha.
        - Remove a couple of extraneous semicolons that were upsetting the
          cparser library. Patch by Christian Grothoff. Fixes bug 7115;
          bugfix on 0.2.2.1-alpha.
        - When complaining about a client port on a public address, log
          which address we're complaining about. Fixes bug 4020; bugfix on
          0.2.3.3-alpha. Patch by Tom Fitzhenry.
    
      o Minor bugfixes (log messages, warnings):
        - If we encounter a write failure on a SOCKS connection before we
          finish our SOCKS handshake, don't warn that we closed the
          connection before we could send a SOCKS reply. Fixes bug 8427;
          bugfix on 0.1.0.1-rc.
        - Fix a directory authority warn caused when we have a large amount
          of badexit bandwidth. Fixes bug 8419; bugfix on 0.2.2.10-alpha.
        - Downgrade "Failed to hand off onionskin" messages to "debug"
          severity, since they're typically redundant with the "Your computer
          is too slow" messages. Fixes bug 7038; bugfix on 0.2.2.16-alpha.
        - Avoid spurious warnings when configuring multiple client ports of
          which only some are nonlocal. Previously, we had claimed that some
          were nonlocal when in fact they weren't. Fixes bug 7836; bugfix on
          0.2.3.3-alpha.
    
      o Minor bugfixes (log messages, other):
        - Fix log messages and comments to avoid saying "GMT" when we mean
          "UTC". Fixes bug 6113.
        - When rejecting a configuration because we were unable to parse a
          quoted string, log an actual error message. Fixes bug 7950; bugfix
          on 0.2.0.16-alpha.
        - Correctly recognize that [::1] is a loopback address. Fixes
          bug 8377; bugfix on 0.2.1.3-alpha.
        - Don't log inappropriate heartbeat messages when hibernating: a
          hibernating node is _expected_ to drop out of the consensus,
          decide it isn't bootstrapped, and so forth. Fixes bug 7302;
          bugfix on 0.2.3.1-alpha.
        - Eliminate several instances where we use "Nickname=ID" to refer to
          nodes in logs. Use "Nickname (ID)" instead. (Elsewhere, we still use
          "$ID=Nickname", which is also acceptable.) Fixes bug 7065. Bugfix
          on 0.2.3.21-rc.
    
      o Minor bugfixes (build):
        - Fix some bugs in tor-fw-helper-natpmp when trying to build and
          run it on Windows. More bugs likely remain. Patch from Gisle Vanem.
          Fixes bug 7280; bugfix on 0.2.3.1-alpha.
    
      o Documentation fixes:
        - Make the torify manpage no longer refer to tsocks; torify hasn't
          supported tsocks since 0.2.3.14-alpha.
        - Make the tor manpage no longer reference tsocks.
        - Fix the GeoIPExcludeUnknown documentation to refer to
          ExcludeExitNodes rather than the currently nonexistent
          ExcludeEntryNodes. Spotted by "hamahangi" on tor-talk.
        - Resolve a typo in torrc.sample.in. Fixes bug 6819; bugfix on
          0.2.3.14-alpha.
        - Say "KBytes" rather than "KB" in the man page (for various values
          of K), to further reduce confusion about whether Tor counts in
          units of memory or fractions of units of memory. Resolves ticket 7054.
        - Update tor-fw-helper.1.txt and tor-fw-helper.c to make option
          names match. Fixes bug 7768.
        - Fix the documentation of HeartbeatPeriod to say that the heartbeat
          message is logged at notice, not at info.
        - Clarify the usage and risks of setting the ContactInfo torrc line
          for your relay or bridge. Resolves ticket 9854.
        - Add anchors to the manpage so we can link to the html version of
          the documentation for specific options. Resolves ticket 9866.
        - Replace remaining references to DirServer in man page and
          log entries. Resolves ticket 10124.
    
      o Removed features:
        - Stop exporting estimates of v2 and v3 directory traffic shares
          in extrainfo documents. They were unneeded and sometimes inaccurate.
          Also stop exporting any v2 directory request statistics. Resolves
          ticket 5823.
        - Drop support for detecting and warning about versions of Libevent
          before 1.3e. Nothing reasonable ships with them any longer; warning
          the user about them shouldn't be needed. Resolves ticket 6826.
        - Now that all versions before 0.2.2.x are disallowed, we no longer
          need to work around their missing features. Remove a bunch of
          compatibility code.
    
      o Removed files:
        - The tor-tsocks.conf is no longer distributed or installed. We
          recommend that tsocks users use torsocks instead. Resolves
          ticket 8290.
        - Remove some of the older contents of doc/ as obsolete; move others
          to torspec.git. Fixes bug 8965.
    
      o Code simplification:
        - Avoid using character buffers when constructing most directory
          objects: this approach was unwieldy and error-prone. Instead,
          build smartlists of strings, and concatenate them when done.
        - Rename "isin" functions to "contains", for grammar. Resolves
          ticket 5285.
        - Rename Tor's logging function log() to tor_log(), to avoid conflicts
          with the natural logarithm function from the system libm. Resolves
          ticket 7599.
        - Start using OpenBSD's implementation of queue.h, so that we don't
          need to hand-roll our own pointer and list structures whenever we
          need them. (We can't rely on a sys/queue.h, since some operating
          systems don't have them, and the ones that do have them don't all
          present the same extensions.)
        - Start using OpenBSD's implementation of queue.h (originally by
          Niels Provos).
        - Enhance our internal sscanf replacement so that we can eliminate
          the last remaining uses of the system sscanf. (Though those uses
          of sscanf were safe, sscanf itself is generally error prone, so
          we want to eliminate when we can.) Fixes ticket 4195 and Coverity
          CID 448.
        - Replace all calls to snprintf() outside of src/ext with
          tor_snprintf(). Also remove the #define to replace snprintf with
          _snprintf on Windows; they have different semantics, and all of
          our callers should be using tor_snprintf() anyway. Fixes bug 7304.
    
      o Refactoring:
        - Add a wrapper function for the common "log a message with a
          rate-limit" case.
        - Split the onion.c file into separate modules for the onion queue
          and the different handshakes it supports.
        - Move the client-side address-map/virtual-address/DNS-cache code
          out of connection_edge.c into a new addressmap.c module.
        - Move the entry node code from circuitbuild.c to its own file.
        - Move the circuit build timeout tracking code from circuitbuild.c
          to its own file.
        - Source files taken from other packages now reside in src/ext;
          previously they were scattered around the rest of Tor.
        - Move the generic "config" code into a new file, and have "config.c"
          hold only torrc- and state-related code. Resolves ticket 6823.
        - Move the core of our "choose a weighted element at random" logic
          into its own function, and give it unit tests. Now the logic is
          testable, and a little less fragile too.
        - Move ipv6_preferred from routerinfo_t to node_t. Addresses bug 4620.
        - Move last_reachable and testing_since from routerinfo_t to node_t.
          Implements ticket 5529.
        - Add replaycache_t structure, functions and unit tests, then refactor
          rend_service_introduce() to be more clear to read, improve, debug,
          and test. Resolves bug 6177.
    
      o Removed code:
        - Remove some now-needless code that tried to aggressively flush
          OR connections as data was added to them. Since 0.2.0.1-alpha, our
          cell queue logic has saved us from the failure mode that this code
          was supposed to prevent. Removing this code will limit the number
          of baroque control flow paths through Tor's network logic. Reported
          pseudonymously on IRC. Fixes bug 6468; bugfix on 0.2.0.1-alpha.
        - Remove unused code for parsing v1 directories and "running routers"
          documents. Fixes bug 6887.
        - Remove the marshalling/unmarshalling code for sending requests to
          cpuworkers over a socket, and instead just send structs. The
          recipient will always be the same Tor binary as the sender, so
          any encoding is overkill.
        - Remove the testing_since field of node_t, which hasn't been used
          for anything since 0.2.0.9-alpha.
        - Finally remove support for malloc_good_size and malloc_usable_size.
          We had hoped that these functions would let us eke a little more
          memory out of our malloc implementation. Unfortunately, the only
          implementations that provided these functions are also ones that
          are already efficient about not overallocation: they never got us
          more than 7 or so bytes per allocation. Removing them saves us a
          little code complexity and a nontrivial amount of build complexity.
    
    
    Changes in version 0.2.3.25 - 2012-11-19
      The Tor 0.2.3 release series is dedicated to the memory of Len "rabbi"
      Sassaman (1980-2011), a long-time cypherpunk, anonymity researcher,
      Mixmaster maintainer, Pynchon Gate co-designer, CodeCon organizer,
      programmer, and friend. Unstinting in his dedication to the cause of
      freedom, he inspired and helped many of us as we began our work on
      anonymity, and inspires us still. Please honor his memory by writing
      software to protect people's freedoms, and by helping others to do so.
    
      Tor 0.2.3.25, the first stable release in the 0.2.3 branch, features
      significantly reduced directory overhead (via microdescriptors),
      enormous crypto performance improvements for fast relays on new
      enough hardware, a new v3 TLS handshake protocol that can better
      resist fingerprinting, support for protocol obfuscation plugins (aka
      pluggable transports), better scalability for hidden services, IPv6
      support for bridges, performance improvements like allowing clients
      to skip the first round-trip on the circuit ("optimistic data") and
      refilling token buckets more often, a new "stream isolation" design
      to isolate different applications on different circuits, and many
      stability, security, and privacy fixes.
    
      Major features (v3 directory protocol):
        - Clients now use microdescriptors instead of regular descriptors
          to build circuits. Microdescriptors are authority-generated
          summaries of regular descriptors' contents, designed to change very
          rarely (see proposal 158 for details). This feature is designed
          to save bandwidth, especially for clients on slow internet
          connections. Use "UseMicrodescriptors 0" to disable it.
        - Caches now download, cache, and serve microdescriptors, as well
          as multiple "flavors" of the consensus, including a flavor that
          describes microdescriptors.
    
      o Major features (build hardening):
        - Enable gcc and ld hardening by default. Resolves ticket 5210.
    
      o Major features (relay scaling):
        - When built to use OpenSSL 1.0.1, and built for an x86 or x86_64
          instruction set, take advantage of OpenSSL's AESNI, bitsliced, or
          vectorized AES implementations as appropriate. These can be much,
          much faster than other AES implementations.
        - When using OpenSSL 1.0.0 or later, use OpenSSL's counter mode
          implementation. It makes AES_CTR about 7% faster than our old one
          (which was about 10% faster than the one OpenSSL used to provide).
          Resolves ticket 4526.
        - Use OpenSSL's EVP interface for AES encryption, so that all AES
          operations can use hardware acceleration (if present). Resolves
          ticket 4442.
        - Unconditionally use OpenSSL's AES implementation instead of our
          old built-in one. OpenSSL's AES has been better for a while, and
          relatively few servers should still be on any version of OpenSSL
          that doesn't have good optimized assembly AES.
    
      o Major features (blocking resistance):
        - Update TLS cipher list to match Firefox 8 and later. Resolves
          ticket 4744.
        - Remove support for clients falsely claiming to support standard
          ciphersuites that they can actually provide. As of modern OpenSSL
          versions, it's not necessary to fake any standard ciphersuite,
          and doing so prevents us from using better ciphersuites in the
          future, since servers can't know whether an advertised ciphersuite
          is really supported or not. Some hosts -- notably, ones with very
          old versions of OpenSSL or where OpenSSL has been built with ECC
          disabled -- will stand out because of this change; TBB users should
          not be affected. Implements the client side of proposal 198.
        - Implement a new handshake protocol (v3) for authenticating Tors to
          each other over TLS. It should be more resistant to fingerprinting
          than previous protocols, and should require less TLS hacking for
          future Tor implementations. Implements proposal 176.
        - Allow variable-length padding cells, to disguise the length of
          Tor's TLS records. Implements part of proposal 184.
        - While we're trying to bootstrap, record how many TLS connections
          fail in each state, and report which states saw the most failures
          in response to any bootstrap failures. This feature may speed up
          diagnosis of censorship events. Implements ticket 3116.
    
      o Major features (pluggable transports):
        - Clients and bridges can now be configured to use a separate
          "transport" proxy. This approach makes the censorship arms race
          easier by allowing bridges to use protocol obfuscation plugins.
          Implements proposal 180 (tickets 2841 and 3472).
    
      o Major features (DoS resistance):
        - Now that Tor 0.2.0.x is completely deprecated, enable the final
          part of "Proposal 110: Avoiding infinite length circuits" by
          refusing all circuit-extend requests that do not use a relay_early
          cell. This change helps Tor resist a class of denial-of-service
          attacks by limiting the maximum circuit length.
        - Tear down the circuit if we get an unexpected SENDME cell. Clients
          could use this trick to make their circuits receive cells faster
          than our flow control would have allowed, or to gum up the network,
          or possibly to do targeted memory denial-of-service attacks on
          entry nodes. Fixes bug 6252. Bugfix on the 54th commit on Tor --
          from July 2002, before the release of Tor 0.0.0.
    
      o Major features (hidden services):
        - Adjust the number of introduction points that a hidden service
          will try to maintain based on how long its introduction points
          remain in use and how many introductions they handle. Fixes
          part of bug 3825.
        - Add a "tor2web mode" for clients that want to connect to hidden
          services non-anonymously (and possibly more quickly). As a safety
          measure to try to keep users from turning this on without knowing
          what they are doing, tor2web mode must be explicitly enabled at
          compile time, and a copy of Tor compiled to run in tor2web mode
          cannot be used as a normal Tor client. Implements feature 2553.
    
      o Major features (IPv6):
        - Clients can now connect to private bridges over IPv6. Bridges
          still need at least one IPv4 address in order to connect to
          other relays. Note that we don't yet handle the case where the
          user has two bridge lines for the same bridge (one IPv4, one
          IPv6). Implements parts of proposal 186.
    
      o Major features (directory authorities):
        - Use a more secure consensus parameter voting algorithm. Now at
          least three directory authorities or a majority of them must
          vote on a given parameter before it will be included in the
          consensus. Implements proposal 178.
        - Remove the artificially low cutoff of 20KB to guarantee the Fast
          flag. In the past few years the average relay speed has picked
          up, and while the "top 7/8 of the network get the Fast flag" and
          "all relays with 20KB or more of capacity get the Fast flag" rules
          used to have the same result, now the top 7/8 of the network has
          a capacity more like 32KB. Bugfix on 0.2.1.14-rc. Fixes bug 4489.
    
      o Major features (performance):
        - Exit nodes now accept and queue data on not-yet-connected streams.
          Previously, the client wasn't allowed to send data until the
          stream was connected, which slowed down all connections. This
          change will enable clients to perform a "fast-start" on streams
          and send data without having to wait for a confirmation that the
          stream has opened. Patch from Ian Goldberg; implements the server
          side of Proposal 174.
        - When using an exit relay running 0.2.3.x, clients can now
          "optimistically" send data before the exit relay reports that
          the stream has opened. This saves a round trip when starting
          connections where the client speaks first (such as web browsing).
          This behavior is controlled by a consensus parameter (currently
          disabled). To turn it on or off manually, use the "OptimisticData"
          torrc option. Implements proposal 181; code by Ian Goldberg.
        - Add a new TokenBucketRefillInterval option to refill token buckets
          more frequently than once per second. This should improve network
          performance, alleviate queueing problems, and make traffic less
          bursty. Implements proposal 183; closes ticket 3630. Design by
          Florian Tschorsch and Björn Scheuermann; implementation by
          Florian Tschorsch.
        - Raise the threshold of server descriptors needed (75%) and exit
          server descriptors needed (50%) before we will declare ourselves
          bootstrapped. This will make clients start building circuits a
          little later, but makes the initially constructed circuits less
          skewed and less in conflict with further directory fetches. Fixes
          ticket 3196.
    
      o Major features (relays):
        - Relays now try regenerating and uploading their descriptor more
          frequently if they are not listed in the consensus, or if the
          version of their descriptor listed in the consensus is too
          old. This fix should prevent situations where a server declines
          to re-publish itself because it has done so too recently, even
          though the authorities decided not to list its recent-enough
          descriptor. Fix for bug 3327.
    
      o Major features (stream isolation):
        - You can now configure Tor so that streams from different
          applications are isolated on different circuits, to prevent an
          attacker who sees your streams as they leave an exit node from
          linking your sessions to one another. To do this, choose some way
          to distinguish the applications: have them connect to different
          SocksPorts, or have one of them use SOCKS4 while the other uses
          SOCKS5, or have them pass different authentication strings to the
          SOCKS proxy. Then, use the new SocksPort syntax to configure the
          degree of isolation you need. This implements Proposal 171.
        - There's a new syntax for specifying multiple client ports (such as
          SOCKSPort, TransPort, DNSPort, NATDPort): you can now just declare
          multiple *Port entries with full addr:port syntax on each.
          The old *ListenAddress format is still supported, but you can't
          mix it with the new *Port syntax.
    
      o Major features (bufferevents):
        - Tor can now optionally build with the "bufferevents" buffered IO
          backend provided by Libevent 2. To use this feature, make sure you
          have the latest possible version of Libevent, and pass the
          --enable-bufferevents flag to configure when building Tor from
          source. This feature will make our networking code more flexible,
          let us stack layers on each other, and let us use more efficient
          zero-copy transports where available.
        - Add experimental support for running on Windows with IOCP and no
          kernel-space socket buffers. This feature is controlled by a new
          "UserspaceIOCPBuffers" config option (off by default), which has
          no effect unless Tor has been built with bufferevents enabled,
          you're running on Windows, and you've set "DisableIOCP 0". In the
          long run, this may help solve or mitigate bug 98.
    
      o Major features (path selection):
        - The EntryNodes option can now include country codes like {de} or IP
          addresses or network masks. Previously we had disallowed these
          options because we didn't have an efficient way to keep the list up
          to date. Addresses ticket 1982, but see bug 2798 for an unresolved
          issue here.
    
      o Major features (port forwarding):
        - Add support for automatic port mapping on the many home routers
          that support NAT-PMP or UPnP. To build the support code, you'll
          need to have the libnatpnp library and/or the libminiupnpc library,
          and you'll need to enable the feature specifically by passing
          "--enable-upnp" and/or "--enable-natpnp" to ./configure. To turn
          it on, use the new PortForwarding option.
    
      o Major features (logging):
        - Add a new 'Heartbeat' log message type to periodically log a message
          describing Tor's status at level Notice. This feature is meant for
          operators who log at notice, and want to make sure that their Tor
          server is still working. Implementation by George Kadianakis.
        - Make logging resolution configurable with a new LogTimeGranularity
          option, and change the default from 1 millisecond to 1 second.
          Implements enhancement 1668.
    
      o Major features (other):
        - New "DisableNetwork" config option to prevent Tor from launching any
          connections or accepting any connections except on a control port.
          Bundles and controllers can set this option before letting Tor talk
          to the rest of the network, for example to prevent any connections
          to a non-bridge address. Packages like Orbot can also use this
          option to instruct Tor to save power when the network is off.
        - Try to use system facilities for enumerating local interface
          addresses, before falling back to our old approach (which was
          binding a UDP socket, and calling getsockname() on it). That
          approach was scaring OS X users whose draconian firewall
          software warned about binding to UDP sockets regardless of
          whether packets were sent. Now we try to use getifaddrs(),
          SIOCGIFCONF, or GetAdaptersAddresses(), depending on what the
          system supports. Resolves ticket 1827.
        - Add experimental support for a "defaults" torrc file to be parsed
          before the regular torrc. Torrc options override the defaults file's
          options in the same way that the command line overrides the torrc.
          The SAVECONF controller command saves only those options which
          differ between the current configuration and the defaults file. HUP
          reloads both files. Implements task 4552.
    
      o New directory authorities:
        - Add Faravahar (run by Sina Rabbani) as the ninth v3 directory
          authority. Closes ticket 5749.
    
      o Security/privacy fixes:
        - Avoid read-from-freed-memory and double-free bugs that could occur
          when a DNS request fails while launching it. Fixes bug 6480;
          bugfix on 0.2.0.1-alpha.
        - Reject any attempt to extend to an internal address. Without
          this fix, a router could be used to probe addresses on an internal
          network to see whether they were accepting connections. Fixes bug
          6710; bugfix on 0.0.8pre1.
        - Close any connection that sends unrecognized junk before the TLS
          handshake. Solves an issue noted in bug 4369.
        - The advertised platform of a relay now includes only its operating
          system's name (e.g., "Linux", "Darwin", "Windows 7"), and not
          its service pack level (for Windows) or its CPU architecture
          (for Unix). Also drop the "git-XYZ" tag in the version. Packagers
          can insert an extra string in the platform line by setting the
          preprocessor variable TOR_BUILD_TAG. Resolves bug 2988.
        - Disable TLS session tickets. OpenSSL's implementation was giving
          our TLS session keys the lifetime of our TLS context objects, when
          perfect forward secrecy would want us to discard anything that
          could decrypt a link connection as soon as the link connection
          was closed. Fixes bug 7139; bugfix on all versions of Tor linked
          against OpenSSL 1.0.0 or later. Found by Florent Daignière.
        - Tor tries to wipe potentially sensitive data after using it, so
          that if some subsequent security failure exposes Tor's memory,
          the damage will be limited. But we had a bug where the compiler
          was eliminating these wipe operations when it decided that the
          memory was no longer visible to a (correctly running) program,
          hence defeating our attempt at defense in depth. We fix that
          by using OpenSSL's OPENSSL_cleanse() operation, which a compiler
          is unlikely to optimize away. Future versions of Tor may use
          a less ridiculously heavy approach for this. Fixes bug 7352.
          Reported in an article by Andrey Karpov.
    
      o Major bugfixes (crashes and asserts):
        - Avoid a pair of double-free and use-after-mark bugs that can
          occur with certain timings in canceled and re-received DNS
          requests. Fixes bug 6472; bugfix on 0.0.7rc1.
        - Fix a denial of service attack by which any directory authority
          could crash all the others, or by which a single v2 directory
          authority could crash everybody downloading v2 directory
          information. Fixes bug 7191; bugfix on 0.2.0.10-alpha.
        - Fix an assert that directory authorities could trigger on sighup
          during some configuration state transitions. We now don't treat
          it as a fatal error when the new descriptor we just generated in
          init_keys() isn't accepted. Fixes bug 4438; bugfix on 0.2.1.9-alpha.
        - Avoid segfault when starting up having run with an extremely old
          version of Tor and parsing its state file. Fixes bug 6801; bugfix
          on 0.2.2.23-alpha.
    
      o Major bugfixes (clients):
        - If we are unable to find any exit that supports our predicted ports,
          stop calling them predicted, so that we don't loop and build
          hopeless circuits indefinitely. Fixes bug 3296; bugfix on 0.0.9pre6,
          which introduced predicted ports.
        - Check at each new consensus whether our entry guards were picked
          long enough ago that we should rotate them. Previously, we only
          did this check at startup, which could lead to us holding a guard
          indefinitely. Fixes bug 5380; bugfix on 0.2.1.14-rc.
        - When fetching a bridge descriptor from a bridge authority,
          always do so anonymously, whether we have been able to open
          circuits or not. Partial fix for bug 1938; bugfix on 0.2.0.7-alpha.
          This behavior makes it *safer* to use UpdateBridgesFromAuthority,
          but we'll need to wait for bug 6010 before it's actually usable.
    
      o Major bugfixes (directory voting):
        - Check more thoroughly to prevent a rogue authority from
          double-voting on any consensus directory parameter. Previously,
          authorities would crash in this case if the total number of
          votes for any parameter exceeded the number of active voters,
          but would let it pass otherwise. Partially fixes bug 5786; bugfix
          on 0.2.2.2-alpha.
        - When computing weight parameters, behave more robustly in the
          presence of a bad bwweightscale value. Previously, the authorities
          would crash if they agreed on a sufficiently broken weight_scale
          value; now, they use a reasonable default and carry on. Fixes the
          rest of bug 5786; bugfix on 0.2.2.17-alpha.
        - If authorities are unable to get a v2 consensus document from other
          directory authorities, they no longer fall back to fetching
          them from regular directory caches. Fixes bug 5635; bugfix on
          0.2.2.26-beta, where routers stopped downloading v2 consensus
          documents entirely.
    
      o Major bugfixes (relays):
        - Fix a bug handling SENDME cells on nonexistent streams that could
          result in bizarre window values. Report and patch contributed
          pseudonymously. Fixes part of bug 6271. This bug was introduced
          before the first Tor release, in svn commit r152.
        - Don't update the AccountingSoftLimitHitAt state file entry whenever
          tor gets started. This prevents a wrong average bandwidth
          estimate, which would cause relays to always start a new accounting
          interval at the earliest possible moment. Fixes bug 2003; bugfix
          on 0.2.2.7-alpha. Reported by Bryon Eldridge, who also helped
          immensely in tracking this bug down.
        - Fix a possible crash bug when checking for deactivated circuits
          in connection_or_flush_from_first_active_circuit(). Fixes bug 6341;
          bugfix on 0.2.2.7-alpha. Bug report and fix received pseudonymously.
        - Set the SO_REUSEADDR socket option before we call bind() on outgoing
          connections. This change should allow busy exit relays to stop
          running out of available sockets as quickly. Fixes bug 4950;
          bugfix on 0.2.2.26-beta.
    
      o Major bugfixes (blocking resistance):
        - Bridges no longer include their address in NETINFO cells on outgoing
          OR connections, to allow them to blend in better with clients.
          Removes another avenue for enumerating bridges. Reported by
          "troll_un". Fixes bug 4348; bugfix on 0.2.0.10-alpha, when NETINFO
          cells were introduced.
        - Warn the user when HTTPProxy, but no other proxy type, is
          configured. This can cause surprising behavior: it doesn't send
          all of Tor's traffic over the HTTPProxy -- it sends unencrypted
          directory traffic only. Resolves ticket 4663.
    
      o Major bugfixes (hidden services):
        - Improve hidden service robustness: when an attempt to connect to
          a hidden service ends, be willing to refetch its hidden service
          descriptors from each of the HSDir relays responsible for them
          immediately. Previously, we would not consider refetching the
          service's descriptors from each HSDir for 15 minutes after the last
          fetch, which was inconvenient if the hidden service was not running
          during the first attempt. Bugfix on 0.2.0.18-alpha; fixes bug 3335.
        - Hidden services now ignore the timestamps on INTRODUCE2 cells.
          They used to check that the timestamp was within 30 minutes
          of their system clock, so they could cap the size of their
          replay-detection cache, but that approach unnecessarily refused
          service to clients with wrong clocks. Bugfix on 0.2.1.6-alpha, when
          the v3 intro-point protocol (the first one which sent a timestamp
          field in the INTRODUCE2 cell) was introduced; fixes bug 3460.
        - When one of a hidden service's introduction points appears to be
          unreachable, stop trying it. Previously, we would keep trying
          to build circuits to the introduction point until we lost the
          descriptor, usually because the user gave up and restarted Tor.
          Fixes part of bug 3825.
    
      o Changes to default torrc file:
        - Stop listing "socksport 9050" in torrc.sample. We open a socks
          port on 9050 by default anyway, so this should not change anything
          in practice.
        - Stop mentioning the deprecated *ListenAddress options in
          torrc.sample. Fixes bug 5438.
        - Document unit of bandwidth-related options in sample torrc.
          Fixes bug 5621.
        - Fix broken URLs in the sample torrc file, and tell readers about
          the OutboundBindAddress, ExitPolicyRejectPrivate, and
          PublishServerDescriptor options. Addresses bug 4652.
    
      o Minor features (directory authorities):
        - Consider new, removed or changed IPv6 OR ports a non-cosmetic
          change when the authority is deciding whether to accept a newly
          uploaded descriptor. Implements ticket 6423.
        - Directory authorities are now a little more lenient at accepting
          older router descriptors, or newer router descriptors that don't
          make big changes. This should help ameliorate past and future
          issues where routers think they have uploaded valid descriptors,
          but the authorities don't think so. Fix for ticket 2479.
        - Authority operators can now vote for all relays in a given
          set of countries to be BadDir/BadExit/Invalid/Rejected.
        - Provide two consensus parameters (FastFlagMinThreshold and
          FastFlagMaxThreshold) to control the range of allowable bandwidths
          for the Fast directory flag. These allow authorities to run
          experiments on appropriate requirements for being a "Fast" node.
          The AuthDirFastGuarantee config value still applies. Implements
          ticket 3946.
    
      o Minor features (bridges / bridge authorities):
        - Make bridge SSL certificates a bit more stealthy by using random
          serial numbers, in the same fashion as OpenSSL when generating
          self-signed certificates. Implements ticket 4584.
        - Tag a bridge's descriptor as "never to be sent unencrypted".
          This shouldn't matter, since bridges don't open non-anonymous
          connections to the bridge authority and don't allow unencrypted
          directory connections from clients, but we might as well make
          sure. Closes bug 5139.
        - The Bridge Authority now writes statistics on how many bridge
          descriptors it gave out in total, and how many unique descriptors
          it gave out. It also lists how often the most and least commonly
          fetched descriptors were given out, as well as the median and
          25th/75th percentile. Implements tickets 4200 and 4294.
    
      o Minor features (IPv6):
        - Make the code that clients use to detect an address change be
          IPv6-aware, so that it won't fill clients' logs with error
          messages when trying to get the IPv4 address of an IPv6
          connection. Implements ticket 5537.
        - Relays now understand an IPv6 address when they get one from a
          directory server. Resolves ticket 4875.
    
      o Minor features (hidden services):
        - Expire old or over-used hidden service introduction points.
          Required by fix for bug 3460.
        - Reduce the lifetime of elements of hidden services' Diffie-Hellman
          public key replay-detection cache from 60 minutes to 5 minutes. This
          replay-detection cache is now used only to detect multiple
          INTRODUCE2 cells specifying the same rendezvous point, so we can
          avoid launching multiple simultaneous attempts to connect to it.
        - When a hidden service's introduction point times out, consider
          trying it again during the next attempt to connect to the
          HS. Previously, we would not try it again unless a newly fetched
          descriptor contained it. Required by fixes for bugs 1297 and 3825.
    
      o Minor features (relays):
        - Relays now include a reason for regenerating their descriptors
          in an HTTP header when uploading to the authorities. This will
          make it easier to debug descriptor-upload issues in the future.
        - Turn on directory request statistics by default and include them in
          extra-info descriptors. Don't break if we have no GeoIP database.
        - Replace files in stats/ rather than appending to them. Now that we
          include statistics in extra-info descriptors, it makes no sense to
          keep old statistics forever. Implements ticket 2930.
        - Relays that set "ConnDirectionStatistics 1" write statistics on the
          bidirectional use of connections to disk every 24 hours.
        - Add a GeoIP file digest to the extra-info descriptor. Implements
          ticket 1883.
    
      o Minor features (new config options):
        - New config option "DynamicDHGroups" (disabled by default) provides
          each bridge with a unique prime DH modulus to be used during
          SSL handshakes. This option attempts to help against censors
          who might use the Apache DH modulus as a static identifier for
          bridges. Addresses ticket 4548.
        - New config option "DisableDebuggerAttachment" (on by default)
          to prevent basic debugging attachment attempts by other processes.
          Supports Mac OS X and Gnu/Linux. Resolves ticket 3313.
        - Ordinarily, Tor does not count traffic from private addresses (like
          127.0.0.1 or 10.0.0.1) when calculating rate limits or accounting.
          There is now a new option, CountPrivateBandwidth, to disable this
          behavior. Patch from Daniel Cagara.
    
      o Minor features (different behavior for old config options):
        - Allow MapAddress directives to specify matches against super-domains,
          as in "MapAddress *.torproject.org *.torproject.org.torserver.exit".
          Implements issue 933.
        - Don't disable the DirPort when we cannot exceed our AccountingMax
          limit during this interval because the effective bandwidthrate is
          low enough. This is useful in a situation where AccountMax is only
          used as an additional safeguard or to provide statistics.
        - Add port 6523 (Gobby) to LongLivedPorts. Patch by intrigeri;
          implements ticket 3439.
        - When configuring a large set of nodes in EntryNodes, and there are
          enough of them listed as Guard so that we don't need to consider
          the non-guard entries, prefer the ones listed with the Guard flag.
        - If you set the NumCPUs option to 0, Tor will now try to detect how
          many CPUs you have. This is the new default behavior.
        - The NodeFamily option -- which let you declare that you want to
          consider nodes to be part of a family whether they list themselves
          that way or not -- now allows IP address ranges and country codes.
    
      o Minor features (new command-line config behavior):
        - Slightly change behavior of "list" options (that is, config
          options that can appear more than once) when they appear both in
          torrc and on the command line. Previously, the command-line options
          would be appended to the ones from torrc. Now, the command-line
          options override the torrc options entirely. This new behavior
          allows the user to override list options (like exit policies and
          ports to listen on) from the command line, rather than simply
          appending to the list.
        - You can get the old (appending) command-line behavior for "list"
          options by prefixing the option name with a "+".
        - You can remove all the values for a "list" option from the command
          line without adding any new ones by prefixing the option name
          with a "/".
    
      o Minor features (controller, new events):
        - Extend the control protocol to report flags that control a circuit's
          path selection in CIRC events and in replies to 'GETINFO
          circuit-status'. Implements part of ticket 2411.
        - Extend the control protocol to report the hidden service address
          and current state of a hidden-service-related circuit in CIRC
          events and in replies to 'GETINFO circuit-status'. Implements part
          of ticket 2411.
        - Include the creation time of a circuit in CIRC and CIRC2
          control-port events and the list produced by the 'GETINFO
          circuit-status' control-port command.
        - Add a new CONF_CHANGED event so that controllers can be notified
          of any configuration changes made by other controllers, or by the
          user. Implements ticket 1692.
        - Add a new SIGNAL event to the controller interface so that
          controllers can be notified when Tor handles a signal. Resolves
          issue 1955. Patch by John Brooks.
    
      o Minor features (controller, new getinfo options):
        - Expose our view of whether we have gone dormant to the controller,
          via a new "GETINFO dormant" value. Torbutton and other controllers
          can use this to avoid doing periodic requests through Tor while
          it's dormant (bug 4718). Resolves ticket 5954.
        - Add a new GETINFO option to get total bytes read and written. Patch
          from pipe, revised by atagar. Resolves ticket 2345.
        - Implement new GETINFO controller fields to provide information about
          the Tor process's pid, euid, username, and resource limits.
    
      o Minor features (controller, other):
        - Allow controllers to request an event notification whenever a
          circuit is cannibalized or its purpose is changed. Implements
          part of ticket 3457.
        - Use absolute path names when reporting the torrc filename in the
          control protocol, so a controller can more easily find the torrc
          file. Resolves bug 1101.
        - When reporting the path to the cookie file to the controller,
          give an absolute path. Resolves ticket 4881.
    
      o Minor features (log messages):
        - Add more information to a log statement that might help track down
          bug 4091. If you're seeing "Bug: tor_addr_is_internal() called with a
          non-IP address" messages (or any Bug messages, for that matter!),
          please let us know about it.
        - If EntryNodes are given, but UseEntryGuards is set to 0, warn that
          EntryNodes will have no effect. Resolves issue 2571.
        - Try to make the introductory warning message that Tor prints on
          startup more useful for actually finding help and information.
          Resolves ticket 2474.
        - When the system call to create a listener socket fails, log the
          error message explaining why. This may help diagnose bug 4027.
    
      o Minor features (other):
        - When we fail to initialize Libevent, retry with IOCP disabled so we
          don't need to turn on multi-threading support in Libevent, which in
          turn requires a working socketpair(). This is a workaround for bug
          4457, which affects Libevent versions from 2.0.1-alpha through
          2.0.15-stable.
        - When starting as root and then changing our UID via the User
          control option, and we have a ControlSocket configured, make sure
          that the ControlSocket is owned by the same account that Tor will
          run under. Implements ticket 3421; fix by Jérémy Bobbio.
        - Accept attempts to include a password authenticator in the
          handshake, as supported by SOCKS5. This handles SOCKS clients that
          don't know how to omit a password when authenticating. Resolves
          bug 1666.
        - Check for and recover from inconsistency in the microdescriptor
          cache. This will make it harder for us to accidentally free a
          microdescriptor without removing it from the appropriate data
          structures. Fixes issue 3135; issue noted by "wanoskarnet".
        - Shorten links in the tor-exit-notice file. Patch by Christian Kujau.
    
      o Minor bugfixes (code security):
        - Prevent a null-pointer dereference when receiving a data cell
          for a nonexistent stream when the circuit in question has an
          empty deliver window. We don't believe this is triggerable,
          since we don't currently allow deliver windows to become empty,
          but the logic is tricky enough that it's better to make the code
          robust. Fixes bug 5541; bugfix on 0.0.2pre14.
        - Fix a (harmless) integer overflow in cell statistics reported by
          some fast relays. Fixes bug 5849; bugfix on 0.2.2.1-alpha.
        - Fix our implementation of crypto_random_hostname() so it can't
          overflow on ridiculously large inputs. (No Tor version has ever
          provided this kind of bad inputs, but let's be correct in depth.)
          Fixes bug 4413; bugfix on 0.2.2.9-alpha. Fix by Stephen Palmateer.
        - Add a (probably redundant) memory clear between iterations of
          the router status voting loop, to prevent future coding errors
          where data might leak between iterations of the loop. Resolves
          ticket 6514.
    
      o Minor bugfixes (wrapper functions):
        - Abort if tor_vasprintf() fails in connection_printf_to_buf() (a
          utility function used in the control-port code). This shouldn't
          ever happen unless Tor is completely out of memory, but if it did
          happen and Tor somehow recovered from it, Tor could have sent a log
          message to a control port in the middle of a reply to a controller
          command. Fixes part of bug 3428; bugfix on 0.1.2.3-alpha.
        - Fix some (not actually triggerable) buffer size checks in usage of
          tor_inet_ntop(). Fixes bug 4434; bugfix on Tor 0.2.0.1-alpha. Patch
          by Anders Sundman.
        - Fix parsing of some corner-cases with tor_inet_pton(). Fixes
          bug 4515; bugfix on 0.2.0.1-alpha; fix by Anders Sundman.
        - Enforce correct return behavior of tor_vsscanf() when the '%%'
          pattern is used. Fixes bug 5558. Bugfix on 0.2.1.13.
        - Make our replacement implementation of strtok_r() compatible with
          the standard behavior of strtok_r(). Patch by nils. Fixes bug 5091;
          bugfix on 0.2.2.1-alpha.
        - Find more places in the code that should have been testing for
          invalid sockets using the SOCKET_OK macro. Required for a fix
          for bug 4533. Bugfix on 0.2.2.28-beta.
    
      o Minor bugfixes (code correctness):
        - Check return value of fputs() when writing authority certificate
          file. Fixes Coverity issue 709056; bugfix on 0.2.0.1-alpha.
        - When building Tor on Windows with -DUNICODE (not default), ensure
          that error messages, filenames, and DNS server names are always
          NUL-terminated when we convert them to a single-byte encoding.
          Fixes bug 5909; bugfix on 0.2.2.16-alpha.
        - Fix a memory leak when trying to launch a DNS request when the
          nameservers are unconfigurable. Fixes bug 5916; bugfix on Tor
          0.1.2.1-alpha.
        - Correct file sizes when reading binary files on Cygwin, to avoid
          a bug where Tor would fail to read its state file. Fixes bug 6844;
          bugfix on 0.1.2.7-alpha.
        - Make sure to set *socket_error in all error cases in
          connection_connect(), so it can't produce a warning about
          errno being zero from errno_to_orconn_end_reason(). Bugfix on
          0.2.1.1-alpha; resolves ticket 6028.
        - Initialize conn->addr to a valid state in spawn_cpuworker(). Fixes
          bug 4532; found by "troll_un".
    
      o Minor bugfixes (clients):
        - Allow one-hop directory-fetching circuits the full "circuit build
          timeout" period, rather than just half of it, before failing them
          and marking the relay down. This fix should help reduce cases where
          clients declare relays (or worse, bridges) unreachable because
          the TLS handshake takes a few seconds to complete. Fixes bug 6743;
          bugfix on 0.2.2.2-alpha, where we changed the timeout from a static
          30 seconds.
        - Ensure we don't cannibalize circuits that are longer than three hops
          already, so we don't end up making circuits with 5 or more
          hops. Patch contributed by wanoskarnet. Fixes bug 5231; bugfix on
          0.1.0.1-rc which introduced cannibalization.
    
      o Minor bugfixes (relays):
        - Don't publish a new relay descriptor when we reload our onion key,
          unless the onion key has actually changed. Fixes bug 3263 and
          resolves another cause of bug 1810. Bugfix on 0.1.1.11-alpha.
        - When relays refuse a "create" cell because their queue of pending
          create cells is too big (typically because their cpu can't keep up
          with the arrival rate), send back reason "resource limit" rather
          than reason "internal", so network measurement scripts can get a
          more accurate picture. Bugfix on 0.1.1.11-alpha; fixes bug 7037.
        - Exit nodes don't need to fetch certificates for authorities that
          they don't recognize; only directory authorities, bridges,
          and caches need to do that. Fixes part of bug 2297; bugfix on
          0.2.2.11-alpha.
    
      o Minor bugfixes (directory authority / mirrors):
        - Avoid O(n^2) performance characteristics when parsing a large
          extrainfo cache. Fixes bug 5828; bugfix on 0.2.0.1-alpha.
        - Authorities no longer include any router in their microdescriptor
          consensuses for which they couldn't generate or agree on a
          microdescriptor. Fixes the second piece of bug 6404; fix on
          0.2.2.6-alpha.
        - When checking for requested signatures on the latest consensus
          before serving it to a client, make sure to check the right
          consensus flavor. Bugfix on 0.2.2.6-alpha.
        - Fix an edge case where TestingTorNetwork is set but the authorities
          and relays all have an uptime of zero, so the private Tor network
          could briefly lack support for hidden services. Fixes bug 3886;
          bugfix on 0.2.2.18-alpha.
        - Directory caches no longer refuse to clean out descriptors because
          of missing v2 networkstatus documents, unless they're configured
          to retrieve v2 networkstatus documents. Fixes bug 4838; bugfix on
          0.2.2.26-beta. Patch by Daniel Bryg.
        - Don't serve or accept v2 hidden service descriptors over a relay's
          DirPort. It's never correct to do so, and disabling it might
          make it more annoying to exploit any bugs that turn up in the
          descriptor-parsing code. Fixes bug 7149.
    
      o Minor bugfixes (hidden services, client-side):
        - Assert that hidden-service-related operations are not performed
          using single-hop circuits. Previously, Tor would assert that
          client-side streams are not attached to single-hop circuits,
          but not that other sensitive operations on the client and service
          side are not performed using single-hop circuits. Fixes bug 3332;
          bugfix on 0.0.6.
        - Avoid undefined behavior when parsing the list of supported
          rendezvous/introduction protocols in a hidden service descriptor.
          Previously, Tor would have confused (as-yet-unused) protocol version
          numbers greater than 32 with lower ones on many platforms. Fixes
          bug 6827; bugfix on 0.2.0.10-alpha. Found by George Kadianakis.
        - Don't close hidden service client circuits which have almost
          finished connecting to their destination when they reach
          the normal circuit-build timeout. Previously, we would close
          introduction circuits which are waiting for an acknowledgement
          from the introduction point, and rendezvous circuits which have
          been specified in an INTRODUCE1 cell sent to a hidden service,
          after the normal CBT. Now, we mark them as 'timed out', and launch
          another rendezvous attempt in parallel. This behavior change can
          be disabled using the new CloseHSClientCircuitsImmediatelyOnTimeout
          option. Fixes part of bug 1297; bugfix on 0.2.2.2-alpha.
    
      o Minor bugfixes (hidden services, service-side):
        - Don't close hidden-service-side rendezvous circuits when they
          reach the normal circuit-build timeout. This behavior change can
          be disabled using the new
          CloseHSServiceRendCircuitsImmediatelyOnTimeout option. Fixes the
          remaining part of bug 1297; bugfix on 0.2.2.2-alpha.
        - Don't launch more than 10 service-side introduction-point circuits
          for a hidden service in five minutes. Previously, we would consider
          launching more introduction-point circuits if at least one second
          had passed without any introduction-point circuits failing. Fixes
          bug 4607; bugfix on 0.0.7pre1.
    
      o Minor bugfixes (config option behavior):
        - If the user tries to set MyFamily on a bridge, refuse to
          do so, and warn about the security implications. Fixes bug 4657;
          bugfix on 0.2.0.3-alpha.
        - The "--quiet" and "--hush" options now apply not only to Tor's
          behavior before logs are configured, but also to Tor's behavior in
          the absence of configured logs. Fixes bug 3550; bugfix on
          0.2.0.10-alpha.
        - Change the AllowDotExit rules so they should actually work.
          We now enforce AllowDotExit only immediately after receiving an
          address via SOCKS or DNSPort: other sources are free to provide
          .exit addresses after the resolution occurs. Fixes bug 3940;
          bugfix on 0.2.2.1-alpha.
        - Make "LearnCircuitBuildTimeout 0" work more reliably. Specifically,
          don't depend on the consensus parameters or compute adaptive
          timeouts when it is disabled. Fixes bug 5049; bugfix on
          0.2.2.14-alpha.
        - After we pick a directory mirror, we would refuse to use it if
          it's in our ExcludeExitNodes list, resulting in mysterious failures
          to bootstrap for people who just wanted to avoid exiting from
          certain locations. Fixes bug 5623; bugfix on 0.2.2.25-alpha.
        - When told to add a bridge with the same digest as a preexisting
          bridge but a different addr:port, change the addr:port as
          requested. Previously we would not notice the change. Fixes half
          of bug 5603; fix on 0.2.2.26-beta.
    
      o Minor bugfixes (controller):
        - Allow manual 'authenticate' commands to the controller interface
          from netcat (nc) as well as telnet. We were rejecting them because
          they didn't come with the expected whitespace at the end of the
          command. Bugfix on 0.1.1.1-alpha; fixes bug 2893.
        - Report a real bootstrap problem to the controller on router
          identity mismatch. Previously we just said "foo", which probably
          made a lot of sense at the time. Fixes bug 4169; bugfix on
          0.2.1.1-alpha.
        - When we receive a SIGHUP and the controller __ReloadTorrcOnSIGHUP
          option is set to 0 (which Vidalia version 0.2.16 now does when
          a SAVECONF attempt fails), perform other actions that SIGHUP
          usually causes (like reopening the logs). Fixes bug 5095; bugfix
          on 0.2.1.9-alpha.
        - Correctly handle checking the permissions on the parent
          directory of a control socket in the root directory. Bug found
          by Esteban Manchado Velázquez. Fixes bug 5089; bugfix on Tor
          0.2.2.26-beta.
        - End AUTHCHALLENGE error messages (in the control protocol) with
          a CRLF. Fixes bug 5760; bugfix on 0.2.2.36.
    
      o Minor bugfixes (network reading/writing):
        - Disable writing on marked-for-close connections when they are
          blocked on bandwidth, to prevent busy-looping in Libevent. Fixes
          bug 5263; bugfix on 0.0.2pre13, where we first added a special
          case for flushing marked connections.
        - Make sure that there are no unhandled pending TLS errors before
          reading from a TLS stream. We had checks in 0.1.0.3-rc, but
          lost them in 0.1.0.5-rc when we refactored read_to_buf_tls().
          Bugfix on 0.1.0.5-rc; fixes bug 4528.
        - Detect SSL handshake even when the initial attempt to write the
          server hello fails. Fixes bug 4592; bugfix on 0.2.0.13-alpha.
        - If the client fails to set a reasonable set of ciphersuites
          during its v2 handshake renegotiation, allow the renegotiation to
          continue nevertheless (i.e. send all the required certificates).
          Fixes bug 4591; bugfix on 0.2.0.20-rc.
    
      o Minor bugfixes (other):
        - Exit nodes now correctly report EADDRINUSE and EADDRNOTAVAIL as
          resource exhaustion, so that clients can adjust their load to
          try other exits. Fixes bug 4710; bugfix on 0.1.0.1-rc, which
          started using END_STREAM_REASON_RESOURCELIMIT.
        - Don't check for whether the address we're using for outbound
          connections has changed until after the outbound connection has
          completed. On Windows, getsockname() doesn't succeed until the
          connection is finished. Fixes bug 5374; bugfix on 0.1.1.14-alpha.
        - Don't hold a Windows file handle open for every file mapping;
          the file mapping handle is sufficient. Fixes bug 5951; bugfix on
          0.1.2.1-alpha.
        - Fix wrong TCP port range in parse_port_range(). Fixes bug 6218;
          bugfix on 0.2.1.10-alpha.
        - If we fail to write a microdescriptor to the disk cache, do not
          continue replacing the old microdescriptor file. Fixes bug 2954;
          bugfix on 0.2.2.6-alpha.
    
      o Minor bugfixes (log messages, path selection):
        - Downgrade "set buildtimeout to low value" messages to "info"
          severity; they were never an actual problem, there was never
          anything reasonable to do about them, and they tended to spam logs
          from time to time. Fixes bug 6251; bugfix on 0.2.2.2-alpha.
        - Rate-limit the "Weighted bandwidth is 0.000000" message, and add
          more information to it, so that we can track it down in case it
          returns again. Mitigates bug 5235.
        - Check CircuitBuildTimeout and LearnCircuitBuildTimeout in
          options_validate(); warn if LearnCircuitBuildTimeout is disabled and
          CircuitBuildTimeout is set unreasonably low. Resolves ticket 5452.
        - Issue a log message if a guard completes less than 40% of your
          circuits. Threshold is configurable by torrc option
          PathBiasNoticeRate and consensus parameter pb_noticepct. There is
          additional, off-by-default code to disable guards which fail too
          many circuits. Addresses ticket 5458.
    
      o Minor bugfixes (log messages, client):
        - Downgrade "Got a certificate, but we already have it" log messages
          from warning to info, except when we're a dirauth. Fixes bug 5238;
          bugfix on 0.2.1.7-alpha.
        - Fix the log message describing how we work around discovering
          that our version is the ill-fated OpenSSL 0.9.8l. Fixes bug
          4837; bugfix on 0.2.2.9-alpha.
        - When logging about a disallowed .exit name, do not also call it
          an "invalid onion address". Fixes bug 3325; bugfix on 0.2.2.9-alpha.
        - Fix a log message suggesting that people contact a non-existent
          email address. Fixes bug 3448.
        - Rephrase the log message emitted if the TestSocks check is
          successful. Patch from Fabian Keil; fixes bug 4094.
        - Log (at debug level) whenever a circuit's purpose is changed.
        - Log SSL state transitions at log level DEBUG, log domain
          HANDSHAKE. This can be useful for debugging censorship events.
          Implements ticket 3264.
        - We now log which torrc file we're using on startup. Implements
          ticket 2444.
        - Rate-limit log messages when asked to connect anonymously to
          a private address. When these hit, they tended to hit fast and
          often. Also, don't bother trying to connect to addresses that we
          are sure will resolve to 127.0.0.1: getting 127.0.0.1 in a directory
          reply makes us think we have been lied to, even when the address the
          client tried to connect to was "localhost." Resolves ticket 2822.
    
      o Minor bugfixes (log messages, non-client):
        - Downgrade "eventdns rejected address" message to LOG_PROTOCOL_WARN.
          Fixes bug 5932; bugfix on 0.2.2.7-alpha.
        - Don't log that we have "decided to publish new relay descriptor"
          unless we are actually publishing a descriptor. Fixes bug 3942;
          bugfix on 0.2.2.28-beta.
        - Log which authority we're missing votes from when we go to fetch
          them from the other auths.
        - Replace "Sending publish request" log messages with "Launching
          upload", so that they no longer confusingly imply that we're
          sending something to a directory we might not even be connected
          to yet. Fixes bug 3311; bugfix on 0.2.0.10-alpha.
        - Warn when Tor is configured to use accounting in a way that can
          link a hidden service to some other hidden service or public
          address. Resolves ticket 6490.
        - Fix a minor formatting issue in one of tor-gencert's error messages.
          Fixes bug 4574.
    
      o Testing:
        - Update to the latest version of the tinytest unit testing framework.
          This includes a couple of bugfixes that can be relevant for
          running forked unit tests on Windows, and removes all reserved
          identifiers.
        - Avoid a false positive in the util/threads unit test by increasing
          the maximum timeout time. Fixes bug 6227; bugfix on 0.2.0.4-alpha.
        - Make it possible to set the TestingTorNetwork configuration
          option using AlternateDirAuthority and AlternateBridgeAuthority
          as an alternative to setting DirServer. Addresses ticket 6377.
        - Add a unit test for the environment_variable_names_equal() function.
        - A wide variety of new unit tests by Esteban Manchado Velázquez.
        - Numerous new unit tests for functions in util.c and address.c by
          Anders Sundman.
        - The long-disabled benchmark tests are now split into their own
          ./src/test/bench binary.
        - The benchmark tests can now use more accurate timers than
          gettimeofday() when such timers are available.
        - Use tt_assert(), not tor_assert(), for checking for test failures.
          This makes the unit tests more able to go on in the event that
          one of them fails.
    
      o Build improvements:
        - Use the dead_strip option when building Tor on OS X. This reduces
          binary size by almost 19% when linking openssl and libevent
          statically, which we do for Tor Browser Bundle.
        - Provide a better error message about possible OSX Asciidoc failure
          reasons. Fixes bug 6436.
        - Detect attempts to build Tor on (as yet hypothetical) versions
          of Windows where sizeof(intptr_t) != sizeof(SOCKET). Partial
          fix for bug 4533. Bugfix on 0.2.2.28-beta.
        - On Windows, we now define the _WIN32_WINNT macros only if they
          are not already defined. This lets the person building Tor decide,
          if they want, to require a later version of Windows.
        - Our autogen.sh script now uses autoreconf to launch autoconf,
          automake, and so on. This is more robust against some of the failure
          modes associated with running the autotools pieces on their own.
        - Running "make version" now displays the version of Tor that
          we're about to build. Idea from katmagic; resolves issue 4400.
        - Make 'tor --digests' list hashes of all Tor source files. Bugfix
          on 0.2.2.4-alpha; fixes bug 3427.
        - New --enable-static-tor configure option for building Tor as
          statically as possible. Idea, general hackery and thoughts from
          Alexei Czeskis, John Gilmore, Jacob Appelbaum. Implements ticket
          2702.
        - Limited, experimental support for building with nmake and MSVC.
    
      o Build requirements:
        - Building Tor with bufferevent support now requires Libevent
          2.0.13-stable or later. Previous versions of Libevent had bugs in
          SSL-related bufferevents and related issues that would make Tor
          work badly with bufferevents. Requiring 2.0.13-stable also allows
          Tor with bufferevents to take advantage of Libevent APIs
          introduced after 2.0.8-rc.
        - Our build system requires automake 1.6 or later to create the
          Makefile.in files. Previously, you could have used 1.4.
          This only affects developers and people building Tor from git;
          people who build Tor from the source distribution without changing
          the Makefile.am files should be fine.
        - Detect when we try to build on a platform that doesn't define
          AF_UNSPEC to 0. We don't work there, so refuse to compile.
    
      o Build fixes (compile/link):
        - Format more doubles with %f, not %lf. Patch from grarpamp to make
          Tor build correctly on older BSDs again. Fixes bug 3894; bugfix on
          Tor 0.2.0.8-alpha.
        - When building with --enable-static-tor on OpenBSD, do not
          erroneously attempt to link -lrt. Fixes bug 5103.
        - Set _WIN32_WINNT to 0x0501 consistently throughout the code, so
          that IPv6 stuff will compile on MSVC, and compilation issues
          will be easier to track down. Fixes bug 5861.
        - Fix build and 64-bit compile warnings from --enable-openbsd-malloc.
          Fixes bug 6379. Bugfix on 0.2.0.20-rc.
        - Make Tor build correctly again with -DUNICODE -D_UNICODE defined.
          Fixes bug 6097; bugfix on 0.2.2.16-alpha.
    
      o Build fixes (other):
        - Use the _WIN32 macro throughout our code to detect Windows.
          (Previously we had used the obsolete 'WIN32' and the idiosyncratic
          'MS_WINDOWS'.)
        - Properly handle the case where the build-tree is not the same
          as the source tree when generating src/common/common_sha1.i,
          src/or/micro-revision.i, and src/or/or_sha1.i. Fixes bug 3953;
          bugfix on 0.2.0.1-alpha.
        - During configure, search for library containing cos function as
          libm lives in libcore on some platforms (BeOS/Haiku). Linking
          against libm was hard-coded before. Fixes the first part of bug
          4727; bugfix on 0.2.2.2-alpha. Patch and analysis by Martin Hebnes
          Pedersen.
        - Prevent a false positive from the check-spaces script, by disabling
          the "whitespace between function name and (" check for functions
          named 'op()'.
    
      o Packaging (RPM) changes:
        - Update our default RPM spec files to work with mock and rpmbuild
          on RHEL/Fedora. They have an updated set of dependencies and
          conflicts, a fix for an ancient typo when creating the "_tor"
          user, and better instructions. Thanks to Ondrej Mikle for the
          patch series. Fixes bug 6043.
        - On OpenSUSE, create the /var/run/tor directory on startup if it
          is not already created. Patch from Andreas Stieger. Fixes bug 2573.
    
      o Code refactoring (safety):
        - Do not use SMARTLIST_FOREACH for any loop whose body exceeds
          10 lines. Also, don't nest them. Doing so in the past has
          led to hard-to-debug code. The new style is to use the
          SMARTLIST_FOREACH_{BEGIN,END} pair. Addresses issue 6400.
        - Use macros to indicate OpenSSL versions, so we don't need to worry
          about accidental hexadecimal bit shifts.
        - Use tor_sscanf() in place of scanf() in more places through the
          code. This makes us a little more locale-independent, and
          should help shut up code-analysis tools that can't tell
          a safe sscanf string from a dangerous one.
        - Convert more instances of tor_snprintf+tor_strdup into tor_asprintf.
        - Use the smartlist_add_asprintf() alias more consistently.
    
      o Code refactoring (consolidate):
        - A major revision to our internal node-selecting and listing logic.
          Tor already had at least two major ways to look at the question of
          "which Tor servers do we know about": a list of router descriptors,
          and a list of entries in the current consensus. With
          microdescriptors, we're adding a third. Having so many systems
          without an abstraction layer over them was hurting the codebase.
          Now, we have a new "node_t" abstraction that presents a consistent
          interface to a client's view of a Tor node, and holds (nearly) all
          of the mutable state formerly in routerinfo_t and routerstatus_t.
        - Move tor_gettimeofday_cached() into compat_libevent.c, and use
          Libevent's notion of cached time when possible.
        - Remove duplicate code for invoking getrlimit() from control.c.
        - Use OpenSSL's built-in SSL_state_string_long() instead of our
          own homebrewed ssl_state_to_string() replacement. Patch from
          Emile Snyder. Fixes bug 4653.
        - Change the symmetric cipher interface so that creating and
          initializing a stream cipher are no longer separate functions.
    
      o Code refactoring (separate):
        - Make a new "entry connection" struct as an internal subtype of "edge
          connection", to simplify the code and make exit connections smaller.
        - Split connection_about_to_close() into separate functions for each
          connection type.
        - Rewrite the listener-selection logic so that parsing which ports
          we want to listen on is now separate from binding to the ports
          we want.
    
      o Code refactoring (name changes):
        - Rename a handful of old identifiers, mostly related to crypto
          structures and crypto functions. By convention, our "create an
          object" functions are called "type_new()", our "free an object"
          functions are called "type_free()", and our types indicate that
          they are types only with a final "_t". But a handful of older
          types and functions broke these rules, with function names like
          "type_create" or "subsystem_op_type", or with type names like
          type_env_t.
        - Rename Tor functions that turn strings into addresses, so that
          "parse" indicates that no hostname resolution occurs, and
          "lookup" indicates that hostname resolution may occur. This
          should help prevent mistakes in the future. Fixes bug 3512.
        - Use the name "CERTS" consistently to refer to the new cell type;
          we were calling it CERT in some places and CERTS in others.
        - Use a TOR_INVALID_SOCKET macro when initializing a socket to an
          invalid value, rather than just -1.
        - Rename the bench_{aes,dmap} functions to test_*, so that tinytest
          can pick them up when the tests aren't disabled. Bugfix on
          0.2.2.4-alpha which introduced tinytest.
    
      o Code refactoring (other):
        - Defensively refactor rend_mid_rendezvous() so that protocol
          violations and length checks happen in the beginning. Fixes
          bug 5645.
        - Remove the pure attribute from all functions that used it
          previously. In many cases we assigned it incorrectly, because the
          functions might assert or call impure functions, and we don't have
          evidence that keeping the pure attribute is worthwhile. Implements
          changes suggested in ticket 4421.
        - Move the replay-detection cache for the RSA-encrypted parts of
          INTRODUCE2 cells to the introduction point data structures.
          Previously, we would use one replay-detection cache per hidden
          service. Required by fix for bug 3460.
        - The helper programs tor-gencert, tor-resolve, and tor-checkkey
          no longer link against Libevent: they never used it, but
          our library structure used to force them to link it.
    
      o Removed features and files:
        - Remove all internal support for unpadded RSA. We never used it, and
          it would be a bad idea to start.
        - Remove some workaround code for OpenSSL 0.9.6 (which is no longer
          supported).
        - Remove some redundant #include directives throughout the code.
          Patch from Andrea Gelmini.
        - Remove some old code to remember statistics about which descriptors
          we've served as a directory mirror. The feature wasn't used and
          is outdated now that microdescriptors are around.
        - Remove some old code to work around even older versions of Tor that
          used forked processes to handle DNS requests. Such versions of Tor
          are no longer in use as relays.
        - The "torify" script no longer supports the "tsocks" socksifier
          tool, since tsocks doesn't support DNS and UDP right for Tor.
          Everyone should be using torsocks instead. Fixes bugs 3530 and
          5180. Based on a patch by "ugh".
        - Remove the torrc.bridge file: we don't use it for anything, and
          it had become badly desynchronized from torrc.sample. Resolves
          bug 5622.
    
      o Documentation:
        - Begin a doc/state-contents.txt file to explain the contents of
          the Tor state file. Fixes bug 2987.
        - Clarify the documentation for the Alternate*Authority options.
          Fixes bug 6387.
        - Document the --defaults-torrc option, and the new semantics for
          overriding, extending, and clearing lists of options. Closes
          bug 4748.
        - Add missing man page documentation for consensus and microdesc
          files. Resolves ticket 6732.
        - Fix some typos in the manpages. Patch from A. Costa. Fixes bug 6500.
    
      o Documentation fixes:
        - Improve the manual's documentation for the NT Service command-line
          options. Addresses ticket 3964.
        - Clarify SessionGroup documentation slightly; resolves ticket 5437.
        - Document the changes to the ORPort and DirPort options, and the
          fact that {OR/Dir}ListenAddress is now unnecessary (and
          therefore deprecated). Resolves ticket 5597.
        - Correct a broken faq link in the INSTALL file. Fixes bug 2307.
        - Clarify that hidden services are TCP only. Fixes bug 6024.
    
    
    Changes in version 0.2.2.39 - 2012-09-11
      Tor 0.2.2.39 fixes two more opportunities for remotely triggerable
      assertions.
    
      o Security fixes:
        - Fix an assertion failure in tor_timegm() that could be triggered
          by a badly formatted directory object. Bug found by fuzzing with
          Radamsa. Fixes bug 6811; bugfix on 0.2.0.20-rc.
        - Do not crash when comparing an address with port value 0 to an
          address policy. This bug could have been used to cause a remote
          assertion failure by or against directory authorities, or to
          allow some applications to crash clients. Fixes bug 6690; bugfix
          on 0.2.1.10-alpha.
    
    
    Changes in version 0.2.2.38 - 2012-08-12
      Tor 0.2.2.38 fixes a remotely triggerable crash bug, and fixes a timing
      attack that could in theory leak path information.
    
      o Security fixes:
        - Avoid an uninitialized memory read when reading a vote or consensus
          document that has an unrecognized flavor name. This read could
          lead to a remote crash bug. Fixes bug 6530; bugfix on 0.2.2.6-alpha.
        - Try to leak less information about what relays a client is
          choosing to a side-channel attacker. Previously, a Tor client would
          stop iterating through the list of available relays as soon as it
          had chosen one, thus finishing a little earlier when it picked
          a router earlier in the list. If an attacker can recover this
          timing information (nontrivial but not proven to be impossible),
          they could learn some coarse-grained information about which relays
          a client was picking (middle nodes in particular are likelier to
          be affected than exits). The timing attack might be mitigated by
          other factors (see bug 6537 for some discussion), but it's best
          not to take chances. Fixes bug 6537; bugfix on 0.0.8rc1.
    
    
    Changes in version 0.2.2.37 - 2012-06-06
      Tor 0.2.2.37 introduces a workaround for a critical renegotiation
      bug in OpenSSL 1.0.1 (where 20% of the Tor network can't talk to itself
      currently).
    
      o Major bugfixes:
        - Work around a bug in OpenSSL that broke renegotiation with TLS
          1.1 and TLS 1.2. Without this workaround, all attempts to speak
          the v2 Tor connection protocol when both sides were using OpenSSL
          1.0.1 would fail. Resolves ticket 6033.
        - When waiting for a client to renegotiate, don't allow it to add
          any bytes to the input buffer. This fixes a potential DoS issue.
          Fixes bugs 5934 and 6007; bugfix on 0.2.0.20-rc.
        - Fix an edge case where if we fetch or publish a hidden service
          descriptor, we might build a 4-hop circuit and then use that circuit
          for exiting afterwards -- even if the new last hop doesn't obey our
          ExitNodes config option. Fixes bug 5283; bugfix on 0.2.0.10-alpha.
    
      o Minor bugfixes:
        - Fix a build warning with Clang 3.1 related to our use of vasprintf.
          Fixes bug 5969. Bugfix on 0.2.2.11-alpha.
    
      o Minor features:
        - Tell GCC and Clang to check for any errors in format strings passed
          to the tor_v*(print|scan)f functions.
    
    
    Changes in version 0.2.2.36 - 2012-05-24
      Tor 0.2.2.36 updates the addresses for two of the eight directory
      authorities, fixes some potential anonymity and security issues,
      and fixes several crash bugs.
    
      Tor 0.2.1.x has reached its end-of-life. Those Tor versions have many
      known flaws, and nobody should be using them. You should upgrade. If
      you're using a Linux or BSD and its packages are obsolete, stop using
      those packages and upgrade anyway.
    
      o Directory authority changes:
        - Change IP address for maatuska (v3 directory authority).
        - Change IP address for ides (v3 directory authority), and rename
          it to turtles.
    
      o Security fixes:
        - When building or running with any version of OpenSSL earlier
          than 0.9.8s or 1.0.0f, disable SSLv3 support. These OpenSSL
          versions have a bug (CVE-2011-4576) in which their block cipher
          padding includes uninitialized data, potentially leaking sensitive
          information to any peer with whom they make a SSLv3 connection. Tor
          does not use SSL v3 by default, but a hostile client or server
          could force an SSLv3 connection in order to gain information that
          they shouldn't have been able to get. The best solution here is to
          upgrade to OpenSSL 0.9.8s or 1.0.0f (or later). But when building
          or running with a non-upgraded OpenSSL, we disable SSLv3 entirely
          to make sure that the bug can't happen.
        - Never use a bridge or a controller-supplied node as an exit, even
          if its exit policy allows it. Found by wanoskarnet. Fixes bug
          5342. Bugfix on 0.1.1.15-rc (for controller-purpose descriptors)
          and 0.2.0.3-alpha (for bridge-purpose descriptors).
        - Only build circuits if we have a sufficient threshold of the total
          descriptors that are marked in the consensus with the "Exit"
          flag. This mitigates an attack proposed by wanoskarnet, in which
          all of a client's bridges collude to restrict the exit nodes that
          the client knows about. Fixes bug 5343.
        - Provide controllers with a safer way to implement the cookie
          authentication mechanism. With the old method, if another locally
          running program could convince a controller that it was the Tor
          process, then that program could trick the controller into telling
          it the contents of an arbitrary 32-byte file. The new "SAFECOOKIE"
          authentication method uses a challenge-response approach to prevent
          this attack. Fixes bug 5185; implements proposal 193.
    
      o Major bugfixes:
        - Avoid logging uninitialized data when unable to decode a hidden
          service descriptor cookie. Fixes bug 5647; bugfix on 0.2.1.5-alpha.
        - Avoid a client-side assertion failure when receiving an INTRODUCE2
          cell on a general purpose circuit. Fixes bug 5644; bugfix on
          0.2.1.6-alpha.
        - Fix builds when the path to sed, openssl, or sha1sum contains
          spaces, which is pretty common on Windows. Fixes bug 5065; bugfix
          on 0.2.2.1-alpha.
        - Correct our replacements for the timeradd() and timersub() functions
          on platforms that lack them (for example, Windows). The timersub()
          function is used when expiring circuits, while timeradd() is
          currently unused. Bug report and patch by Vektor. Fixes bug 4778;
          bugfix on 0.2.2.24-alpha.
        - Fix the SOCKET_OK test that we use to tell when socket
          creation fails so that it works on Win64. Fixes part of bug 4533;
          bugfix on 0.2.2.29-beta. Bug found by wanoskarnet.
    
      o Minor bugfixes:
        - Reject out-of-range times like 23:59:61 in parse_rfc1123_time().
          Fixes bug 5346; bugfix on 0.0.8pre3.
        - Make our number-parsing functions always treat too-large values
          as an error, even when those values exceed the width of the
          underlying type. Previously, if the caller provided these
          functions with minima or maxima set to the extreme values of the
          underlying integer type, these functions would return those
          values on overflow rather than treating overflow as an error.
          Fixes part of bug 5786; bugfix on 0.0.9.
        - Older Linux kernels erroneously respond to strange nmap behavior
          by having accept() return successfully with a zero-length
          socket. When this happens, just close the connection. Previously,
          we would try harder to learn the remote address: but there was
          no such remote address to learn, and our method for trying to
          learn it was incorrect. Fixes bugs 1240, 4745, and 4747. Bugfix
          on 0.1.0.3-rc. Reported and diagnosed by "r1eo".
        - Correct parsing of certain date types in parse_http_time().
          Without this patch, If-Modified-Since would behave
          incorrectly. Fixes bug 5346; bugfix on 0.2.0.2-alpha. Patch from
          Esteban Manchado Velázques.
        - Change the BridgePassword feature (part of the "bridge community"
          design, which is not yet implemented) to use a time-independent
          comparison. The old behavior might have allowed an adversary
          to use timing to guess the BridgePassword value. Fixes bug 5543;
          bugfix on 0.2.0.14-alpha.
        - Detect and reject certain misformed escape sequences in
          configuration values. Previously, these values would cause us
          to crash if received in a torrc file or over an authenticated
          control port. Bug found by Esteban Manchado Velázquez, and
          independently by Robert Connolly from Matta Consulting who further
          noted that it allows a post-authentication heap overflow. Patch
          by Alexander Schrijver. Fixes bugs 5090 and 5402 (CVE 2012-1668);
          bugfix on 0.2.0.16-alpha.
        - Fix a compile warning when using the --enable-openbsd-malloc
          configure option. Fixes bug 5340; bugfix on 0.2.0.20-rc.
        - During configure, detect when we're building with clang version
          3.0 or lower and disable the -Wnormalized=id and -Woverride-init
          CFLAGS. clang doesn't support them yet.
        - When sending an HTTP/1.1 proxy request, include a Host header.
          Fixes bug 5593; bugfix on 0.2.2.1-alpha.
        - Fix a NULL-pointer dereference on a badly formed SETCIRCUITPURPOSE
          command. Found by mikeyc. Fixes bug 5796; bugfix on 0.2.2.9-alpha.
        - If we hit the error case where routerlist_insert() replaces an
          existing (old) server descriptor, make sure to remove that
          server descriptor from the old_routers list. Fix related to bug
          1776. Bugfix on 0.2.2.18-alpha.
    
      o Minor bugfixes (documentation and log messages):
        - Fix a typo in a log message in rend_service_rendezvous_has_opened().
          Fixes bug 4856; bugfix on Tor 0.0.6.
        - Update "ClientOnly" man page entry to explain that there isn't
          really any point to messing with it. Resolves ticket 5005.
        - Document the GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays
          directory authority option (introduced in Tor 0.2.2.34).
        - Downgrade the "We're missing a certificate" message from notice
          to info: people kept mistaking it for a real problem, whereas it
          is seldom the problem even when we are failing to bootstrap. Fixes
          bug 5067; bugfix on 0.2.0.10-alpha.
        - Correctly spell "connect" in a log message on failure to create a
          controlsocket. Fixes bug 4803; bugfix on 0.2.2.26-beta.
        - Clarify the behavior of MaxCircuitDirtiness with hidden service
          circuits. Fixes issue 5259.
    
      o Minor features:
        - Directory authorities now reject versions of Tor older than
          0.2.1.30, and Tor versions between 0.2.2.1-alpha and 0.2.2.20-alpha
          inclusive. These versions accounted for only a small fraction of
          the Tor network, and have numerous known security issues. Resolves
          issue 4788.
        - Update to the May 1 2012 Maxmind GeoLite Country database.
    
      - Feature removal:
        - When sending or relaying a RELAY_EARLY cell, we used to convert
          it to a RELAY cell if the connection was using the v1 link
          protocol. This was a workaround for older versions of Tor, which
          didn't handle RELAY_EARLY cells properly. Now that all supported
          versions can handle RELAY_EARLY cells, and now that we're enforcing
          the "no RELAY_EXTEND commands except in RELAY_EARLY cells" rule,
          remove this workaround. Addresses bug 4786.
    
    
    Changes in version 0.2.2.35 - 2011-12-16
      Tor 0.2.2.35 fixes a critical heap-overflow security issue in Tor's
      buffers code. Absolutely everybody should upgrade.
    
      The bug relied on an incorrect calculation when making data continuous
      in one of our IO buffers, if the first chunk of the buffer was
      misaligned by just the wrong amount. The miscalculation would allow an
      attacker to overflow a piece of heap-allocated memory. To mount this
      attack, the attacker would need to either open a SOCKS connection to
      Tor's SocksPort (usually restricted to localhost), or target a Tor
      instance configured to make its connections through a SOCKS proxy
      (which Tor does not do by default).
    
      Good security practice requires that all heap-overflow bugs should be
      presumed to be exploitable until proven otherwise, so we are treating
      this as a potential code execution attack. Please upgrade immediately!
      This bug does not affect bufferevents-based builds of Tor. Special
      thanks to "Vektor" for reporting this issue to us!
    
      Tor 0.2.2.35 also fixes several bugs in previous versions, including
      crash bugs for unusual configurations, and a long-term bug that
      would prevent Tor from starting on Windows machines with draconian
      AV software.
    
      With this release, we remind everyone that 0.2.0.x has reached its
      formal end-of-life. Those Tor versions have many known flaws, and
      nobody should be using them. You should upgrade -- ideally to the
      0.2.2.x series. If you're using a Linux or BSD and its packages are
      obsolete, stop using those packages and upgrade anyway.
    
      The Tor 0.2.1.x series is also approaching its end-of-life: it will no
      longer receive support after some time in early 2012.
    
      o Major bugfixes:
        - Fix a heap overflow bug that could occur when trying to pull
          data into the first chunk of a buffer, when that chunk had
          already had some data drained from it. Fixes CVE-2011-2778;
          bugfix on 0.2.0.16-alpha. Reported by "Vektor".
        - Initialize Libevent with the EVENT_BASE_FLAG_NOLOCK flag enabled, so
          that it doesn't attempt to allocate a socketpair. This could cause
          some problems on Windows systems with overzealous firewalls. Fix for
          bug 4457; workaround for Libevent versions 2.0.1-alpha through
          2.0.15-stable.
        - If we mark an OR connection for close based on a cell we process,
          don't process any further cells on it. We already avoid further
          reads on marked-for-close connections, but now we also discard the
          cells we'd already read. Fixes bug 4299; bugfix on 0.2.0.10-alpha,
          which was the first version where we might mark a connection for
          close based on processing a cell on it.
        - Correctly sanity-check that we don't underflow on a memory
          allocation (and then assert) for hidden service introduction
          point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410;
          bugfix on 0.2.1.5-alpha.
        - Fix a memory leak when we check whether a hidden service
          descriptor has any usable introduction points left. Fixes bug
          4424. Bugfix on 0.2.2.25-alpha.
        - Don't crash when we're running as a relay and don't have a GeoIP
          file. Bugfix on 0.2.2.34; fixes bug 4340. This backports a fix
          we've had in the 0.2.3.x branch already.
        - When running as a client, do not print a misleading (and plain
          wrong) log message that we're collecting "directory request"
          statistics: clients don't collect statistics. Also don't create a
          useless (because empty) stats file in the stats/ directory. Fixes
          bug 4353; bugfix on 0.2.2.34.
    
      o Minor bugfixes:
        - Detect failure to initialize Libevent. This fix provides better
          detection for future instances of bug 4457.
        - Avoid frequent calls to the fairly expensive cull_wedged_cpuworkers
          function. This was eating up hideously large amounts of time on some
          busy servers. Fixes bug 4518; bugfix on 0.0.9.8.
        - Resolve an integer overflow bug in smartlist_ensure_capacity().
          Fixes bug 4230; bugfix on Tor 0.1.0.1-rc. Based on a patch by
          Mansour Moufid.
        - Don't warn about unused log_mutex in log.c when building with
          --disable-threads using a recent GCC. Fixes bug 4437; bugfix on
          0.1.0.6-rc which introduced --disable-threads.
        - When configuring, starting, or stopping an NT service, stop
          immediately after the service configuration attempt has succeeded
          or failed. Fixes bug 3963; bugfix on 0.2.0.7-alpha.
        - When sending a NETINFO cell, include the original address
          received for the other side, not its canonical address. Found
          by "troll_un"; fixes bug 4349; bugfix on 0.2.0.10-alpha.
        - Fix a typo in a hibernation-related log message. Fixes bug 4331;
          bugfix on 0.2.2.23-alpha; found by "tmpname0901".
        - Fix a memory leak in launch_direct_bridge_descriptor_fetch() that
          occurred when a client tried to fetch a descriptor for a bridge
          in ExcludeNodes. Fixes bug 4383; bugfix on 0.2.2.25-alpha.
        - Backport fixes for a pair of compilation warnings on Windows.
          Fixes bug 4521; bugfix on 0.2.2.28-beta and on 0.2.2.29-beta.
        - If we had ever tried to call tor_addr_to_str on an address of
          unknown type, we would have done a strdup on an uninitialized
          buffer. Now we won't. Fixes bug 4529; bugfix on 0.2.1.3-alpha.
          Reported by "troll_un".
        - Correctly detect and handle transient lookup failures from
          tor_addr_lookup. Fixes bug 4530; bugfix on 0.2.1.5-alpha.
          Reported by "troll_un".
        - Fix null-pointer access that could occur if TLS allocation failed.
          Fixes bug 4531; bugfix on 0.2.0.20-rc. Found by "troll_un".
        - Use tor_socket_t type for listener argument to accept(). Fixes bug
          4535; bugfix on 0.2.2.28-beta. Found by "troll_un".
    
      o Minor features:
        - Add two new config options for directory authorities:
          AuthDirFastGuarantee sets a bandwidth threshold for guaranteeing the
          Fast flag, and AuthDirGuardBWGuarantee sets a bandwidth threshold
          that is always sufficient to satisfy the bandwidth requirement for
          the Guard flag. Now it will be easier for researchers to simulate
          Tor networks with different values. Resolves ticket 4484.
        - When Tor ignores a hidden service specified in its configuration,
          include the hidden service's directory in the warning message.
          Previously, we would only tell the user that some hidden service
          was ignored. Bugfix on 0.0.6; fixes bug 4426.
        - Update to the December 6 2011 Maxmind GeoLite Country database.
    
      o Packaging changes:
        - Make it easier to automate expert package builds on Windows,
          by removing an absolute path from makensis.exe command.
    
    
    Changes in version 0.2.1.32 - 2011-12-16
      Tor 0.2.1.32 backports important security and privacy fixes for
      oldstable. This release is intended only for package maintainers and
      others who cannot use the 0.2.2 stable series. All others should be
      using Tor 0.2.2.x or newer.
    
      The Tor 0.2.1.x series will reach formal end-of-life some time in
      early 2012; we will stop releasing patches for it then.
    
      o Major bugfixes (also included in 0.2.2.x):
        - Correctly sanity-check that we don't underflow on a memory
          allocation (and then assert) for hidden service introduction
          point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410;
          bugfix on 0.2.1.5-alpha.
        - Fix a heap overflow bug that could occur when trying to pull
          data into the first chunk of a buffer, when that chunk had
          already had some data drained from it. Fixes CVE-2011-2778;
          bugfix on 0.2.0.16-alpha. Reported by "Vektor".
    
      o Minor features:
        - Update to the December 6 2011 Maxmind GeoLite Country database.
    
    
    Changes in version 0.2.2.34 - 2011-10-26
      Tor 0.2.2.34 fixes a critical anonymity vulnerability where an attacker
      can deanonymize Tor users. Everybody should upgrade.
    
      The attack relies on four components: 1) Clients reuse their TLS cert
      when talking to different relays, so relays can recognize a user by
      the identity key in her cert. 2) An attacker who knows the client's
      identity key can probe each guard relay to see if that identity key
      is connected to that guard relay right now. 3) A variety of active
      attacks in the literature (starting from "Low-Cost Traffic Analysis
      of Tor" by Murdoch and Danezis in 2005) allow a malicious website to
      discover the guard relays that a Tor user visiting the website is using.
      4) Clients typically pick three guards at random, so the set of guards
      for a given user could well be a unique fingerprint for her. This
      release fixes components #1 and #2, which is enough to block the attack;
      the other two remain as open research problems. Special thanks to
      "frosty_un" for reporting the issue to us!
    
      Clients should upgrade so they are no longer recognizable by the TLS
      certs they present. Relays should upgrade so they no longer allow a
      remote attacker to probe them to test whether unpatched clients are
      currently connected to them.
    
      This release also fixes several vulnerabilities that allow an attacker
      to enumerate bridge relays. Some bridge enumeration attacks still
      remain; see for example proposal 188.
    
      o Privacy/anonymity fixes (clients):
        - Clients and bridges no longer send TLS certificate chains on
          outgoing OR connections. Previously, each client or bridge would
          use the same cert chain for all outgoing OR connections until
          its IP address changes, which allowed any relay that the client
          or bridge contacted to determine which entry guards it is using.
          Fixes CVE-2011-2768. Bugfix on 0.0.9pre5; found by "frosty_un".
        - If a relay receives a CREATE_FAST cell on a TLS connection, it
          no longer considers that connection as suitable for satisfying a
          circuit EXTEND request. Now relays can protect clients from the
          CVE-2011-2768 issue even if the clients haven't upgraded yet.
        - Directory authorities no longer assign the Guard flag to relays
          that haven't upgraded to the above "refuse EXTEND requests
          to client connections" fix. Now directory authorities can
          protect clients from the CVE-2011-2768 issue even if neither
          the clients nor the relays have upgraded yet. There's a new
          "GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays" config option
          to let us transition smoothly, else tomorrow there would be no
          guard relays.
    
      o Privacy/anonymity fixes (bridge enumeration):
        - Bridge relays now do their directory fetches inside Tor TLS
          connections, like all the other clients do, rather than connecting
          directly to the DirPort like public relays do. Removes another
          avenue for enumerating bridges. Fixes bug 4115; bugfix on 0.2.0.35.
        - Bridges relays now build circuits for themselves in a more similar
          way to how clients build them. Removes another avenue for
          enumerating bridges. Fixes bug 4124; bugfix on 0.2.0.3-alpha,
          when bridges were introduced.
        - Bridges now refuse CREATE or CREATE_FAST cells on OR connections
          that they initiated. Relays could distinguish incoming bridge
          connections from client connections, creating another avenue for
          enumerating bridges. Fixes CVE-2011-2769. Bugfix on 0.2.0.3-alpha.
          Found by "frosty_un".
    
      o Major bugfixes:
        - Fix a crash bug when changing node restrictions while a DNS lookup
          is in-progress. Fixes bug 4259; bugfix on 0.2.2.25-alpha. Bugfix
          by "Tey'".
        - Don't launch a useless circuit after failing to use one of a
          hidden service's introduction points. Previously, we would
          launch a new introduction circuit, but not set the hidden service
          which that circuit was intended to connect to, so it would never
          actually be used. A different piece of code would then create a
          new introduction circuit correctly. Bug reported by katmagic and
          found by Sebastian Hahn. Bugfix on 0.2.1.13-alpha; fixes bug 4212.
    
      o Minor bugfixes:
        - Change an integer overflow check in the OpenBSD_Malloc code so
          that GCC is less likely to eliminate it as impossible. Patch
          from Mansour Moufid. Fixes bug 4059.
        - When a hidden service turns an extra service-side introduction
          circuit into a general-purpose circuit, free the rend_data and
          intro_key fields first, so we won't leak memory if the circuit
          is cannibalized for use as another service-side introduction
          circuit. Bugfix on 0.2.1.7-alpha; fixes bug 4251.
        - Bridges now skip DNS self-tests, to act a little more stealthily.
          Fixes bug 4201; bugfix on 0.2.0.3-alpha, which first introduced
          bridges. Patch by "warms0x".
        - Fix internal bug-checking logic that was supposed to catch
          failures in digest generation so that it will fail more robustly
          if we ask for a nonexistent algorithm. Found by Coverity Scan.
          Bugfix on 0.2.2.1-alpha; fixes Coverity CID 479.
        - Report any failure in init_keys() calls launched because our
          IP address has changed. Spotted by Coverity Scan. Bugfix on
          0.1.1.4-alpha; fixes CID 484.
    
      o Minor bugfixes (log messages and documentation):
        - Remove a confusing dollar sign from the example fingerprint in the
          man page, and also make the example fingerprint a valid one. Fixes
          bug 4309; bugfix on 0.2.1.3-alpha.
        - The next version of Windows will be called Windows 8, and it has
          a major version of 6, minor version of 2. Correctly identify that
          version instead of calling it "Very recent version". Resolves
          ticket 4153; reported by funkstar.
        - Downgrade log messages about circuit timeout calibration from
          "notice" to "info": they don't require or suggest any human
          intervention. Patch from Tom Lowenthal. Fixes bug 4063;
          bugfix on 0.2.2.14-alpha.
    
      o Minor features:
        - Turn on directory request statistics by default and include them in
          extra-info descriptors. Don't break if we have no GeoIP database.
          Backported from 0.2.3.1-alpha; implements ticket 3951.
        - Update to the October 4 2011 Maxmind GeoLite Country database.
    
    
    Changes in version 0.2.1.31 - 2011-10-26
      Tor 0.2.1.31 backports important security and privacy fixes for
      oldstable. This release is intended only for package maintainers and
      others who cannot use the 0.2.2 stable series. All others should be
      using Tor 0.2.2.x or newer.
    
      o Security fixes (also included in 0.2.2.x):
        - Replace all potentially sensitive memory comparison operations
          with versions whose runtime does not depend on the data being
          compared. This will help resist a class of attacks where an
          adversary can use variations in timing information to learn
          sensitive data. Fix for one case of bug 3122. (Safe memcmp
          implementation by Robert Ransom based partially on code by DJB.)
        - Fix an assert in parsing router descriptors containing IPv6
          addresses. This one took down the directory authorities when
          somebody tried some experimental code. Bugfix on 0.2.1.3-alpha.
    
      o Privacy/anonymity fixes (also included in 0.2.2.x):
        - Clients and bridges no longer send TLS certificate chains on
          outgoing OR connections. Previously, each client or bridge would
          use the same cert chain for all outgoing OR connections until
          its IP address changes, which allowed any relay that the client
          or bridge contacted to determine which entry guards it is using.
          Fixes CVE-2011-2768. Bugfix on 0.0.9pre5; found by "frosty_un".
        - If a relay receives a CREATE_FAST cell on a TLS connection, it
          no longer considers that connection as suitable for satisfying a
          circuit EXTEND request. Now relays can protect clients from the
          CVE-2011-2768 issue even if the clients haven't upgraded yet.
        - Bridges now refuse CREATE or CREATE_FAST cells on OR connections
          that they initiated. Relays could distinguish incoming bridge
          connections from client connections, creating another avenue for
          enumerating bridges. Fixes CVE-2011-2769. Bugfix on 0.2.0.3-alpha.
          Found by "frosty_un".
        - When receiving a hidden service descriptor, check that it is for
          the hidden service we wanted. Previously, Tor would store any
          hidden service descriptors that a directory gave it, whether it
          wanted them or not. This wouldn't have let an attacker impersonate
          a hidden service, but it did let directories pre-seed a client
          with descriptors that it didn't want. Bugfix on 0.0.6.
        - Avoid linkability based on cached hidden service descriptors: forget
          all hidden service descriptors cached as a client when processing a
          SIGNAL NEWNYM command. Fixes bug 3000; bugfix on 0.0.6.
        - Make the bridge directory authority refuse to answer directory
          requests for "all" descriptors. It used to include bridge
          descriptors in its answer, which was a major information leak.
          Found by "piebeer". Bugfix on 0.2.0.3-alpha.
        - Don't attach new streams to old rendezvous circuits after SIGNAL
          NEWNYM. Previously, we would keep using an existing rendezvous
          circuit if it remained open (i.e. if it were kept open by a
          long-lived stream, or if a new stream were attached to it before
          Tor could notice that it was old and no longer in use). Bugfix on
          0.1.1.15-rc; fixes bug 3375.
    
      o Minor bugfixes (also included in 0.2.2.x):
        - When we restart our relay, we might get a successful connection
          from the outside before we've started our reachability tests,
          triggering a warning: "ORPort found reachable, but I have no
          routerinfo yet. Failing to inform controller of success." This
          bug was harmless unless Tor is running under a controller
          like Vidalia, in which case the controller would never get a
          REACHABILITY_SUCCEEDED status event. Bugfix on 0.1.2.6-alpha;
          fixes bug 1172.
        - Build correctly on OSX with zlib 1.2.4 and higher with all warnings
          enabled. Fixes bug 1526.
        - Remove undocumented option "-F" from tor-resolve: it hasn't done
          anything since 0.2.1.16-rc.
        - Avoid signed/unsigned comparisons by making SIZE_T_CEILING unsigned.
          None of the cases where we did this before were wrong, but by making
          this change we avoid warnings. Fixes bug 2475; bugfix on 0.2.1.28.
        - Fix a rare crash bug that could occur when a client was configured
          with a large number of bridges. Fixes bug 2629; bugfix on
          0.2.1.2-alpha. Bugfix by trac user "shitlei".
        - Correct the warning displayed when a rendezvous descriptor exceeds
          the maximum size. Fixes bug 2750; bugfix on 0.2.1.5-alpha. Found by
          John Brooks.
        - Fix an uncommon assertion failure when running with DNSPort under
          heavy load. Fixes bug 2933; bugfix on 0.2.0.1-alpha.
        - When warning about missing zlib development packages during compile,
          give the correct package names. Bugfix on 0.2.0.1-alpha.
        - Require that introduction point keys and onion keys have public
          exponent 65537. Bugfix on 0.2.0.10-alpha.
        - Do not crash when our configuration file becomes unreadable, for
          example due to a permissions change, between when we start up
          and when a controller calls SAVECONF. Fixes bug 3135; bugfix
          on 0.0.9pre6.
        - Fix warnings from GCC 4.6's "-Wunused-but-set-variable" option.
          Fixes bug 3208.
        - Always NUL-terminate the sun_path field of a sockaddr_un before
          passing it to the kernel. (Not a security issue: kernels are
          smart enough to reject bad sockaddr_uns.) Found by Coverity;
          CID #428. Bugfix on Tor 0.2.0.3-alpha.
        - Don't stack-allocate the list of supplementary GIDs when we're
          about to log them. Stack-allocating NGROUPS_MAX gid_t elements
          could take up to 256K, which is way too much stack. Found by
          Coverity; CID #450. Bugfix on 0.2.1.7-alpha.
    
      o Minor bugfixes (only in 0.2.1.x):
        - Resume using micro-version numbers in 0.2.1.x: our Debian packages
          rely on them. Bugfix on 0.2.1.30.
        - Use git revisions instead of svn revisions when generating our
          micro-version numbers. Bugfix on 0.2.1.15-rc; fixes bug 2402.
    
      o Minor features (also included in 0.2.2.x):
        - Adjust the expiration time on our SSL session certificates to
          better match SSL certs seen in the wild. Resolves ticket 4014.
        - Allow nameservers with IPv6 address. Resolves bug 2574.
        - Update to the October 4 2011 Maxmind GeoLite Country database.
    
    
    Changes in version 0.2.2.33 - 2011-09-13
      Tor 0.2.2.33 fixes several bugs, and includes a slight tweak to Tor's
      TLS handshake that makes relays and bridges that run this new version
      reachable from Iran again.
    
      o Major bugfixes:
        - Avoid an assertion failure when reloading a configuration with
          TrackExitHosts changes. Found and fixed by 'laruldan'. Fixes bug
          3923; bugfix on 0.2.2.25-alpha.
    
      o Minor features (security):
        - Check for replays of the public-key encrypted portion of an
          INTRODUCE1 cell, in addition to the current check for replays of
          the g^x value. This prevents a possible class of active attacks
          by an attacker who controls both an introduction point and a
          rendezvous point, and who uses the malleability of AES-CTR to
          alter the encrypted g^x portion of the INTRODUCE1 cell. We think
          that these attacks are infeasible (requiring the attacker to send
          on the order of zettabytes of altered cells in a short interval),
          but we'd rather block them off in case there are any classes of
          this attack that we missed. Reported by Willem Pinckaers.
    
      o Minor features:
        - Adjust the expiration time on our SSL session certificates to
          better match SSL certs seen in the wild. Resolves ticket 4014.
        - Change the default required uptime for a relay to be accepted as
          a HSDir (hidden service directory) from 24 hours to 25 hours.
          Improves on 0.2.0.10-alpha; resolves ticket 2649.
        - Add a VoteOnHidServDirectoriesV2 config option to allow directory
          authorities to abstain from voting on assignment of the HSDir
          consensus flag. Related to bug 2649.
        - Update to the September 6 2011 Maxmind GeoLite Country database.
    
      o Minor bugfixes (documentation and log messages):
        - Correct the man page to explain that HashedControlPassword and
          CookieAuthentication can both be set, in which case either method
          is sufficient to authenticate to Tor. Bugfix on 0.2.0.7-alpha,
          when we decided to allow these config options to both be set. Issue
          raised by bug 3898.
        - Demote the 'replay detected' log message emitted when a hidden
          service receives the same Diffie-Hellman public key in two different
          INTRODUCE2 cells to info level. A normal Tor client can cause that
          log message during its normal operation. Bugfix on 0.2.1.6-alpha;
          fixes part of bug 2442.
        - Demote the 'INTRODUCE2 cell is too {old,new}' log message to info
          level. There is nothing that a hidden service's operator can do
          to fix its clients' clocks. Bugfix on 0.2.1.6-alpha; fixes part
          of bug 2442.
        - Clarify a log message specifying the characters permitted in
          HiddenServiceAuthorizeClient client names. Previously, the log
          message said that "[A-Za-z0-9+-_]" were permitted; that could have
          given the impression that every ASCII character between "+" and "_"
          was permitted. Now we say "[A-Za-z0-9+_-]". Bugfix on 0.2.1.5-alpha.
    
      o Build fixes:
        - Provide a substitute implementation of lround() for MSVC, which
          apparently lacks it. Patch from Gisle Vanem.
        - Clean up some code issues that prevented Tor from building on older
          BSDs. Fixes bug 3894; reported by "grarpamp".
        - Search for a platform-specific version of "ar" when cross-compiling.
          Should fix builds on iOS. Resolves bug 3909, found by Marco Bonetti.
    
    
    Changes in version 0.2.2.32 - 2011-08-27
      The Tor 0.2.2 release series is dedicated to the memory of Andreas
      Pfitzmann (1958-2010), a pioneer in anonymity and privacy research,
      a founder of the PETS community, a leader in our field, a mentor,
      and a friend. He left us with these words: "I had the possibility
      to contribute to this world that is not as it should be. I hope I
      could help in some areas to make the world a better place, and that
      I could also encourage other people to be engaged in improving the
      world. Please, stay engaged. This world needs you, your love, your
      initiative -- now I cannot be part of that anymore."
    
      Tor 0.2.2.32, the first stable release in the 0.2.2 branch, is finally
      ready. More than two years in the making, this release features improved
      client performance and hidden service reliability, better compatibility
      for Android, correct behavior for bridges that listen on more than
      one address, more extensible and flexible directory object handling,
      better reporting of network statistics, improved code security, and
      many many other features and bugfixes.
    
      o Major features (client performance):
        - When choosing which cells to relay first, relays now favor circuits
          that have been quiet recently, to provide lower latency for
          low-volume circuits. By default, relays enable or disable this
          feature based on a setting in the consensus. They can override
          this default by using the new "CircuitPriorityHalflife" config
          option. Design and code by Ian Goldberg, Can Tang, and Chris
          Alexander.
        - Directory authorities now compute consensus weightings that instruct
          clients how to weight relays flagged as Guard, Exit, Guard+Exit,
          and no flag. Clients use these weightings to distribute network load
          more evenly across these different relay types. The weightings are
          in the consensus so we can change them globally in the future. Extra
          thanks to "outofwords" for finding some nasty security bugs in
          the first implementation of this feature.
    
      o Major features (client performance, circuit build timeout):
        - Tor now tracks how long it takes to build client-side circuits
          over time, and adapts its timeout to local network performance.
          Since a circuit that takes a long time to build will also provide
          bad performance, we get significant latency improvements by
          discarding the slowest 20% of circuits. Specifically, Tor creates
          circuits more aggressively than usual until it has enough data
          points for a good timeout estimate. Implements proposal 151.
        - Circuit build timeout constants can be controlled by consensus
          parameters. We set good defaults for these parameters based on
          experimentation on broadband and simulated high-latency links.
        - Circuit build time learning can be disabled via consensus parameter
          or by the client via a LearnCircuitBuildTimeout config option. We
          also automatically disable circuit build time calculation if either
          AuthoritativeDirectory is set, or if we fail to write our state
          file. Implements ticket 1296.
    
      o Major features (relays use their capacity better):
        - Set SO_REUSEADDR socket option on all sockets, not just
          listeners. This should help busy exit nodes avoid running out of
          useable ports just because all the ports have been used in the
          near past. Resolves issue 2850.
        - Relays now save observed peak bandwidth throughput rates to their
          state file (along with total usage, which was already saved),
          so that they can determine their correct estimated bandwidth on
          restart. Resolves bug 1863, where Tor relays would reset their
          estimated bandwidth to 0 after restarting.
        - Lower the maximum weighted-fractional-uptime cutoff to 98%. This
          should give us approximately 40-50% more Guard-flagged nodes,
          improving the anonymity the Tor network can provide and also
          decreasing the dropoff in throughput that relays experience when
          they first get the Guard flag.
        - Directory authorities now take changes in router IP address and
          ORPort into account when determining router stability. Previously,
          if a router changed its IP or ORPort, the authorities would not
          treat it as having any downtime for the purposes of stability
          calculation, whereas clients would experience downtime since the
          change would take a while to propagate to them. Resolves issue 1035.
        - New AccelName and AccelDir options add support for dynamic OpenSSL
          hardware crypto acceleration engines.
    
      o Major features (relays control their load better):
        - Exit relays now try harder to block exit attempts from unknown
          relays, to make it harder for people to use them as one-hop proxies
          a la tortunnel. Controlled by the refuseunknownexits consensus
          parameter (currently enabled), or you can override it on your
          relay with the RefuseUnknownExits torrc option. Resolves bug 1751;
          based on a variant of proposal 163.
        - Add separate per-conn write limiting to go with the per-conn read
          limiting. We added a global write limit in Tor 0.1.2.5-alpha,
          but never per-conn write limits.
        - New consensus params "bwconnrate" and "bwconnburst" to let us
          rate-limit client connections as they enter the network. It's
          controlled in the consensus so we can turn it on and off for
          experiments. It's starting out off. Based on proposal 163.
    
      o Major features (controllers):
        - Export GeoIP information on bridge usage to controllers even if we
          have not yet been running for 24 hours. Now Vidalia bridge operators
          can get more accurate and immediate feedback about their
          contributions to the network.
        - Add an __OwningControllerProcess configuration option and a
          TAKEOWNERSHIP control-port command. Now a Tor controller can ensure
          that when it exits, Tor will shut down. Implements feature 3049.
    
      o Major features (directory authorities):
        - Directory authorities now create, vote on, and serve multiple
          parallel formats of directory data as part of their voting process.
          Partially implements Proposal 162: "Publish the consensus in
          multiple flavors".
        - Directory authorities now agree on and publish small summaries
          of router information that clients can use in place of regular
          server descriptors. This transition will allow Tor 0.2.3 clients
          to use far less bandwidth for downloading information about the
          network. Begins the implementation of Proposal 158: "Clients
          download consensus + microdescriptors".
        - The directory voting system is now extensible to use multiple hash
          algorithms for signatures and resource selection. Newer formats
          are signed with SHA256, with a possibility for moving to a better
          hash algorithm in the future.
        - Directory authorities can now vote on arbitrary integer values as
          part of the consensus process. This is designed to help set
          network-wide parameters. Implements proposal 167.
    
      o Major features and bugfixes (node selection):
        - Revise and reconcile the meaning of the ExitNodes, EntryNodes,
          ExcludeEntryNodes, ExcludeExitNodes, ExcludeNodes, and Strict*Nodes
          options. Previously, we had been ambiguous in describing what
          counted as an "exit" node, and what operations exactly "StrictNodes
          0" would permit. This created confusion when people saw nodes built
          through unexpected circuits, and made it hard to tell real bugs from
          surprises. Now the intended behavior is:
            . "Exit", in the context of ExitNodes and ExcludeExitNodes, means
              a node that delivers user traffic outside the Tor network.
            . "Entry", in the context of EntryNodes, means a node used as the
              first hop of a multihop circuit. It doesn't include direct
              connections to directory servers.
            . "ExcludeNodes" applies to all nodes.
            . "StrictNodes" changes the behavior of ExcludeNodes only. When
              StrictNodes is set, Tor should avoid all nodes listed in
              ExcludeNodes, even when it will make user requests fail. When
              StrictNodes is *not* set, then Tor should follow ExcludeNodes
              whenever it can, except when it must use an excluded node to
              perform self-tests, connect to a hidden service, provide a
              hidden service, fulfill a .exit request, upload directory
              information, or fetch directory information.
          Collectively, the changes to implement the behavior fix bug 1090.
        - If EntryNodes, ExitNodes, ExcludeNodes, or ExcludeExitNodes
          change during a config reload, mark and discard all our origin
          circuits. This fix should address edge cases where we change the
          config options and but then choose a circuit that we created before
          the change.
        - Make EntryNodes config option much more aggressive even when
          StrictNodes is not set. Before it would prepend your requested
          entrynodes to your list of guard nodes, but feel free to use others
          after that. Now it chooses only from your EntryNodes if any of
          those are available, and only falls back to others if a) they're
          all down and b) StrictNodes is not set.
        - Now we refresh your entry guards from EntryNodes at each consensus
          fetch -- rather than just at startup and then they slowly rot as
          the network changes.
        - Add support for the country code "{??}" in torrc options like
          ExcludeNodes, to indicate all routers of unknown country. Closes
          bug 1094.
        - ExcludeNodes now takes precedence over EntryNodes and ExitNodes: if
          a node is listed in both, it's treated as excluded.
        - ExcludeNodes now applies to directory nodes -- as a preference if
          StrictNodes is 0, or an absolute requirement if StrictNodes is 1.
          Don't exclude all the directory authorities and set StrictNodes to 1
          unless you really want your Tor to break.
        - ExcludeNodes and ExcludeExitNodes now override exit enclaving.
        - ExcludeExitNodes now overrides .exit requests.
        - We don't use bridges listed in ExcludeNodes.
        - When StrictNodes is 1:
           . We now apply ExcludeNodes to hidden service introduction points
             and to rendezvous points selected by hidden service users. This
             can make your hidden service less reliable: use it with caution!
           . If we have used ExcludeNodes on ourself, do not try relay
             reachability self-tests.
           . If we have excluded all the directory authorities, we will not
             even try to upload our descriptor if we're a relay.
           . Do not honor .exit requests to an excluded node.
        - When the set of permitted nodes changes, we now remove any mappings
          introduced via TrackExitHosts to now-excluded nodes. Bugfix on
          0.1.0.1-rc.
        - We never cannibalize a circuit that had excluded nodes on it, even
          if StrictNodes is 0. Bugfix on 0.1.0.1-rc.
        - Improve log messages related to excluded nodes.
    
      o Major features (misc):
        - Numerous changes, bugfixes, and workarounds from Nathan Freitas
          to help Tor build correctly for Android phones.
        - The options SocksPort, ControlPort, and so on now all accept a
          value "auto" that opens a socket on an OS-selected port. A
          new ControlPortWriteToFile option tells Tor to write its
          actual control port or ports to a chosen file. If the option
          ControlPortFileGroupReadable is set, the file is created as
          group-readable. Now users can run two Tor clients on the same
          system without needing to manually mess with parameters. Resolves
          part of ticket 3076.
        - Tor now supports tunneling all of its outgoing connections over
          a SOCKS proxy, using the SOCKS4Proxy and/or SOCKS5Proxy
          configuration options. Code by Christopher Davis.
    
      o Code security improvements:
        - Replace all potentially sensitive memory comparison operations
          with versions whose runtime does not depend on the data being
          compared. This will help resist a class of attacks where an
          adversary can use variations in timing information to learn
          sensitive data. Fix for one case of bug 3122. (Safe memcmp
          implementation by Robert Ransom based partially on code by DJB.)
        - Enable Address Space Layout Randomization (ASLR) and Data Execution
          Prevention (DEP) by default on Windows to make it harder for
          attackers to exploit vulnerabilities. Patch from John Brooks.
        - New "--enable-gcc-hardening" ./configure flag (off by default)
          to turn on gcc compile time hardening options. It ensures
          that signed ints have defined behavior (-fwrapv), enables
          -D_FORTIFY_SOURCE=2 (requiring -O2), adds stack smashing protection
          with canaries (-fstack-protector-all), turns on ASLR protection if
          supported by the kernel (-fPIE, -pie), and adds additional security
          related warnings. Verified to work on Mac OS X and Debian Lenny.
        - New "--enable-linker-hardening" ./configure flag (off by default)
          to turn on ELF specific hardening features (relro, now). This does
          not work with Mac OS X or any other non-ELF binary format.
        - Always search the Windows system directory for system DLLs, and
          nowhere else. Bugfix on 0.1.1.23; fixes bug 1954.
        - New DisableAllSwap option. If set to 1, Tor will attempt to lock all
          current and future memory pages via mlockall(). On supported
          platforms (modern Linux and probably BSD but not Windows or OS X),
          this should effectively disable any and all attempts to page out
          memory. This option requires that you start your Tor as root --
          if you use DisableAllSwap, please consider using the User option
          to properly reduce the privileges of your Tor.
    
      o Major bugfixes (crashes):
        - Fix crash bug on platforms where gmtime and localtime can return
          NULL. Windows 7 users were running into this one. Fixes part of bug
          2077. Bugfix on all versions of Tor. Found by boboper.
        - Introduce minimum/maximum values that clients will believe
          from the consensus. Now we'll have a better chance to avoid crashes
          or worse when a consensus param has a weird value.
        - Fix a rare crash bug that could occur when a client was configured
          with a large number of bridges. Fixes bug 2629; bugfix on
          0.2.1.2-alpha. Bugfix by trac user "shitlei".
        - Do not crash when our configuration file becomes unreadable, for
          example due to a permissions change, between when we start up
          and when a controller calls SAVECONF. Fixes bug 3135; bugfix
          on 0.0.9pre6.
        - If we're in the pathological case where there's no exit bandwidth
          but there is non-exit bandwidth, or no guard bandwidth but there
          is non-guard bandwidth, don't crash during path selection. Bugfix
          on 0.2.0.3-alpha.
        - Fix a crash bug when trying to initialize the evdns module in
          Libevent 2. Bugfix on 0.2.1.16-rc.
    
      o Major bugfixes (stability):
        - Fix an assert in parsing router descriptors containing IPv6
          addresses. This one took down the directory authorities when
          somebody tried some experimental code. Bugfix on 0.2.1.3-alpha.
        - Fix an uncommon assertion failure when running with DNSPort under
          heavy load. Fixes bug 2933; bugfix on 0.2.0.1-alpha.
        - Treat an unset $HOME like an empty $HOME rather than triggering an
          assert. Bugfix on 0.0.8pre1; fixes bug 1522.
        - More gracefully handle corrupt state files, removing asserts
          in favor of saving a backup and resetting state.
        - Instead of giving an assertion failure on an internal mismatch
          on estimated freelist size, just log a BUG warning and try later.
          Mitigates but does not fix bug 1125.
        - Fix an assert that got triggered when using the TestingTorNetwork
          configuration option and then issuing a GETINFO config-text control
          command. Fixes bug 2250; bugfix on 0.2.1.2-alpha.
        - If the cached cert file is unparseable, warn but don't exit.
    
      o Privacy fixes (relays/bridges):
        - Don't list Windows capabilities in relay descriptors. We never made
          use of them, and maybe it's a bad idea to publish them. Bugfix
          on 0.1.1.8-alpha.
        - If the Nickname configuration option isn't given, Tor would pick a
          nickname based on the local hostname as the nickname for a relay.
          Because nicknames are not very important in today's Tor and the
          "Unnamed" nickname has been implemented, this is now problematic
          behavior: It leaks information about the hostname without being
          useful at all. Fixes bug 2979; bugfix on 0.1.2.2-alpha, which
          introduced the Unnamed nickname. Reported by tagnaq.
        - Maintain separate TLS contexts and certificates for incoming and
          outgoing connections in bridge relays. Previously we would use the
          same TLS contexts and certs for incoming and outgoing connections.
          Bugfix on 0.2.0.3-alpha; addresses bug 988.
        - Maintain separate identity keys for incoming and outgoing TLS
          contexts in bridge relays. Previously we would use the same
          identity keys for incoming and outgoing TLS contexts. Bugfix on
          0.2.0.3-alpha; addresses the other half of bug 988.
        - Make the bridge directory authority refuse to answer directory
          requests for "all descriptors". It used to include bridge
          descriptors in its answer, which was a major information leak.
          Found by "piebeer". Bugfix on 0.2.0.3-alpha.
    
      o Privacy fixes (clients):
        - When receiving a hidden service descriptor, check that it is for
          the hidden service we wanted. Previously, Tor would store any
          hidden service descriptors that a directory gave it, whether it
          wanted them or not. This wouldn't have let an attacker impersonate
          a hidden service, but it did let directories pre-seed a client
          with descriptors that it didn't want. Bugfix on 0.0.6.
        - Start the process of disabling ".exit" address notation, since it
          can be used for a variety of esoteric application-level attacks
          on users. To reenable it, set "AllowDotExit 1" in your torrc. Fix
          on 0.0.9rc5.
        - Reject attempts at the client side to open connections to private
          IP addresses (like 127.0.0.1, 10.0.0.1, and so on) with
          a randomly chosen exit node. Attempts to do so are always
          ill-defined, generally prevented by exit policies, and usually
          in error. This will also help to detect loops in transparent
          proxy configurations. You can disable this feature by setting
          "ClientRejectInternalAddresses 0" in your torrc.
        - Log a notice when we get a new control connection. Now it's easier
          for security-conscious users to recognize when a local application
          is knocking on their controller door. Suggested by bug 1196.
    
      o Privacy fixes (newnym):
        - Avoid linkability based on cached hidden service descriptors: forget
          all hidden service descriptors cached as a client when processing a
          SIGNAL NEWNYM command. Fixes bug 3000; bugfix on 0.0.6.
        - On SIGHUP, do not clear out all TrackHostExits mappings, client
          DNS cache entries, and virtual address mappings: that's what
          NEWNYM is for. Fixes bug 1345; bugfix on 0.1.0.1-rc.
        - Don't attach new streams to old rendezvous circuits after SIGNAL
          NEWNYM. Previously, we would keep using an existing rendezvous
          circuit if it remained open (i.e. if it were kept open by a
          long-lived stream, or if a new stream were attached to it before
          Tor could notice that it was old and no longer in use). Bugfix on
          0.1.1.15-rc; fixes bug 3375.
    
      o Major bugfixes (relay bandwidth accounting):
        - Fix a bug that could break accounting on 64-bit systems with large
          time_t values, making them hibernate for impossibly long intervals.
          Fixes bug 2146. Bugfix on 0.0.9pre6; fix by boboper.
        - Fix a bug in bandwidth accounting that could make us use twice
          the intended bandwidth when our interval start changes due to
          daylight saving time. Now we tolerate skew in stored vs computed
          interval starts: if the start of the period changes by no more than
          50% of the period's duration, we remember bytes that we transferred
          in the old period. Fixes bug 1511; bugfix on 0.0.9pre5.
    
      o Major bugfixes (bridges):
        - Bridges now use "reject *:*" as their default exit policy. Bugfix
          on 0.2.0.3-alpha. Fixes bug 1113.
        - If you configure your bridge with a known identity fingerprint,
          and the bridge authority is unreachable (as it is in at least
          one country now), fall back to directly requesting the descriptor
          from the bridge. Finishes the feature started in 0.2.0.10-alpha;
          closes bug 1138.
        - Fix a bug where bridge users who configure the non-canonical
          address of a bridge automatically switch to its canonical
          address. If a bridge listens at more than one address, it
          should be able to advertise those addresses independently and
          any non-blocked addresses should continue to work. Bugfix on Tor
          0.2.0.3-alpha. Fixes bug 2510.
        - If you configure Tor to use bridge A, and then quit and
          configure Tor to use bridge B instead (or if you change Tor
          to use bridge B via the controller), it would happily continue
          to use bridge A if it's still reachable. While this behavior is
          a feature if your goal is connectivity, in some scenarios it's a
          dangerous bug. Bugfix on Tor 0.2.0.1-alpha; fixes bug 2511.
        - When the controller configures a new bridge, don't wait 10 to 60
          seconds before trying to fetch its descriptor. Bugfix on
          0.2.0.3-alpha; fixes bug 3198 (suggested by 2355).
    
      o Major bugfixes (directory authorities):
        - Many relays have been falling out of the consensus lately because
          not enough authorities know about their descriptor for them to get
          a majority of votes. When we deprecated the v2 directory protocol,
          we got rid of the only way that v3 authorities can hear from each
          other about other descriptors. Now authorities examine every v3
          vote for new descriptors, and fetch them from that authority. Bugfix
          on 0.2.1.23.
        - Authorities could be tricked into giving out the Exit flag to relays
          that didn't allow exiting to any ports. This bug could screw
          with load balancing and stats. Bugfix on 0.1.1.6-alpha; fixes bug
          1238. Bug discovered by Martin Kowalczyk.
        - If all authorities restart at once right before a consensus vote,
          nobody will vote about "Running", and clients will get a consensus
          with no usable relays. Instead, authorities refuse to build a
          consensus if this happens. Bugfix on 0.2.0.10-alpha; fixes bug 1066.
    
      o Major bugfixes (stream-level fairness):
        - When receiving a circuit-level SENDME for a blocked circuit, try
          to package cells fairly from all the streams that had previously
          been blocked on that circuit. Previously, we had started with the
          oldest stream, and allowed each stream to potentially exhaust
          the circuit's package window. This gave older streams on any
          given circuit priority over newer ones. Fixes bug 1937. Detected
          originally by Camilo Viecco. This bug was introduced before the
          first Tor release, in svn commit r152: it is the new winner of
          the longest-lived bug prize.
        - Fix a stream fairness bug that would cause newer streams on a given
          circuit to get preference when reading bytes from the origin or
          destination. Fixes bug 2210. Fix by Mashael AlSabah. This bug was
          introduced before the first Tor release, in svn revision r152.
        - When the exit relay got a circuit-level sendme cell, it started
          reading on the exit streams, even if had 500 cells queued in the
          circuit queue already, so the circuit queue just grew and grew in
          some cases. We fix this by not re-enabling reading on receipt of a
          sendme cell when the cell queue is blocked. Fixes bug 1653. Bugfix
          on 0.2.0.1-alpha. Detected by Mashael AlSabah. Original patch by
          "yetonetime".
        - Newly created streams were allowed to read cells onto circuits,
          even if the circuit's cell queue was blocked and waiting to drain.
          This created potential unfairness, as older streams would be
          blocked, but newer streams would gladly fill the queue completely.
          We add code to detect this situation and prevent any stream from
          getting more than one free cell. Bugfix on 0.2.0.1-alpha. Partially
          fixes bug 1298.
    
      o Major bugfixes (hidden services):
        - Apply circuit timeouts to opened hidden-service-related circuits
          based on the correct start time. Previously, we would apply the
          circuit build timeout based on time since the circuit's creation;
          it was supposed to be applied based on time since the circuit
          entered its current state. Bugfix on 0.0.6; fixes part of bug 1297.
        - Improve hidden service robustness: When we find that we have
          extended a hidden service's introduction circuit to a relay not
          listed as an introduction point in the HS descriptor we currently
          have, retry with an introduction point from the current
          descriptor. Previously we would just give up. Fixes bugs 1024 and
          1930; bugfix on 0.2.0.10-alpha.
        - Directory authorities now use data collected from their own
          uptime observations when choosing whether to assign the HSDir flag
          to relays, instead of trusting the uptime value the relay reports in
          its descriptor. This change helps prevent an attack where a small
          set of nodes with frequently-changing identity keys can blackhole
          a hidden service. (Only authorities need upgrade; others will be
          fine once they do.) Bugfix on 0.2.0.10-alpha; fixes bug 2709.
        - Stop assigning the HSDir flag to relays that disable their
          DirPort (and thus will refuse to answer directory requests). This
          fix should dramatically improve the reachability of hidden services:
          hidden services and hidden service clients pick six HSDir relays
          to store and retrieve the hidden service descriptor, and currently
          about half of the HSDir relays will refuse to work. Bugfix on
          0.2.0.10-alpha; fixes part of bug 1693.
    
      o Major bugfixes (misc):
        - Clients now stop trying to use an exit node associated with a given
          destination by TrackHostExits if they fail to reach that exit node.
          Fixes bug 2999. Bugfix on 0.2.0.20-rc.
        - Fix a regression that caused Tor to rebind its ports if it receives
          SIGHUP while hibernating. Bugfix in 0.1.1.6-alpha; closes bug 919.
        - Remove an extra pair of quotation marks around the error
          message in control-port STATUS_GENERAL BUG events. Bugfix on
          0.1.2.6-alpha; fixes bug 3732.
    
      o Minor features (relays):
        - Ensure that no empty [dirreq-](read|write)-history lines are added
          to an extrainfo document. Implements ticket 2497.
        - When bandwidth accounting is enabled, be more generous with how
          much bandwidth we'll use up before entering "soft hibernation".
          Previously, we'd refuse new connections and circuits once we'd
          used up 95% of our allotment. Now, we use up 95% of our allotment,
          AND make sure that we have no more than 500MB (or 3 hours of
          expected traffic, whichever is lower) remaining before we enter
          soft hibernation.
        - Relays now log the reason for publishing a new relay descriptor,
          so we have a better chance of hunting down instances of bug 1810.
          Resolves ticket 3252.
        - Log a little more clearly about the times at which we're no longer
          accepting new connections (e.g. due to hibernating). Resolves
          bug 2181.
        - When AllowSingleHopExits is set, print a warning to explain to the
          relay operator why most clients are avoiding her relay.
        - Send END_STREAM_REASON_NOROUTE in response to EHOSTUNREACH errors.
          Clients before 0.2.1.27 didn't handle NOROUTE correctly, but such
          clients are already deprecated because of security bugs.
    
      o Minor features (network statistics):
        - Directory mirrors that set "DirReqStatistics 1" write statistics
          about directory requests to disk every 24 hours. As compared to the
          "--enable-geoip-stats" ./configure flag in 0.2.1.x, there are a few
          improvements: 1) stats are written to disk exactly every 24 hours;
          2) estimated shares of v2 and v3 requests are determined as mean
          values, not at the end of a measurement period; 3) unresolved
          requests are listed with country code '??'; 4) directories also
          measure download times.
        - Exit nodes that set "ExitPortStatistics 1" write statistics on the
          number of exit streams and transferred bytes per port to disk every
          24 hours.
        - Relays that set "CellStatistics 1" write statistics on how long
          cells spend in their circuit queues to disk every 24 hours.
        - Entry nodes that set "EntryStatistics 1" write statistics on the
          rough number and origins of connecting clients to disk every 24
          hours.
        - Relays that write any of the above statistics to disk and set
          "ExtraInfoStatistics 1" include the past 24 hours of statistics in
          their extra-info documents. Implements proposal 166.
    
      o Minor features (GeoIP and statistics):
        - Provide a log message stating which geoip file we're parsing
          instead of just stating that we're parsing the geoip file.
          Implements ticket 2432.
        - Make sure every relay writes a state file at least every 12 hours.
          Previously, a relay could go for weeks without writing its state
          file, and on a crash could lose its bandwidth history, capacity
          estimates, client country statistics, and so on. Addresses bug 3012.
        - Relays report the number of bytes spent on answering directory
          requests in extra-info descriptors similar to {read,write}-history.
          Implements enhancement 1790.
        - Report only the top 10 ports in exit-port stats in order not to
          exceed the maximum extra-info descriptor length of 50 KB. Implements
          task 2196.
        - If writing the state file to disk fails, wait up to an hour before
          retrying again, rather than trying again each second. Fixes bug
          2346; bugfix on Tor 0.1.1.3-alpha.
        - Delay geoip stats collection by bridges for 6 hours, not 2 hours,
          when we switch from being a public relay to a bridge. Otherwise
          there will still be clients that see the relay in their consensus,
          and the stats will end up wrong. Bugfix on 0.2.1.15-rc; fixes
          bug 932.
        - Update to the August 2 2011 Maxmind GeoLite Country database.
    
      o Minor features (clients):
        - When expiring circuits, use microsecond timers rather than
          one-second timers. This can avoid an unpleasant situation where a
          circuit is launched near the end of one second and expired right
          near the beginning of the next, and prevent fluctuations in circuit
          timeout values.
        - If we've configured EntryNodes and our network goes away and/or all
          our entrynodes get marked down, optimistically retry them all when
          a new socks application request appears. Fixes bug 1882.
        - Always perform router selections using weighted relay bandwidth,
          even if we don't need a high capacity circuit at the time. Non-fast
          circuits now only differ from fast ones in that they can use relays
          not marked with the Fast flag. This "feature" could turn out to
          be a horrible bug; we should investigate more before it goes into
          a stable release.
        - When we run out of directory information such that we can't build
          circuits, but then get enough that we can build circuits, log when
          we actually construct a circuit, so the user has a better chance of
          knowing what's going on. Fixes bug 1362.
        - Log SSL state transitions at debug level during handshake, and
          include SSL states in error messages. This may help debug future
          SSL handshake issues.
    
      o Minor features (directory authorities):
        - When a router changes IP address or port, authorities now launch
          a new reachability test for it. Implements ticket 1899.
        - Directory authorities now reject relays running any versions of
          Tor between 0.2.1.3-alpha and 0.2.1.18 inclusive; they have
          known bugs that keep RELAY_EARLY cells from working on rendezvous
          circuits. Followup to fix for bug 2081.
        - Directory authorities now reject relays running any version of Tor
          older than 0.2.0.26-rc. That version is the earliest that fetches
          current directory information correctly. Fixes bug 2156.
        - Directory authorities now do an immediate reachability check as soon
          as they hear about a new relay. This change should slightly reduce
          the time between setting up a relay and getting listed as running
          in the consensus. It should also improve the time between setting
          up a bridge and seeing use by bridge users.
        - Directory authorities no longer launch a TLS connection to every
          relay as they startup. Now that we have 2k+ descriptors cached,
          the resulting network hiccup is becoming a burden. Besides,
          authorities already avoid voting about Running for the first half
          hour of their uptime.
        - Directory authorities now log the source of a rejected POSTed v3
          networkstatus vote, so we can track failures better.
        - Backport code from 0.2.3.x that allows directory authorities to
          clean their microdescriptor caches. Needed to resolve bug 2230.
    
      o Minor features (hidden services):
        - Use computed circuit-build timeouts to decide when to launch
          parallel introduction circuits for hidden services. (Previously,
          we would retry after 15 seconds.)
        - Don't allow v0 hidden service authorities to act as clients.
          Required by fix for bug 3000.
        - Ignore SIGNAL NEWNYM commands on relay-only Tor instances. Required
          by fix for bug 3000.
        - Make hidden services work better in private Tor networks by not
          requiring any uptime to join the hidden service descriptor
          DHT. Implements ticket 2088.
        - Log (at info level) when purging pieces of hidden-service-client
          state because of SIGNAL NEWNYM.
    
      o Minor features (controller interface):
        - New "GETINFO net/listeners/(type)" controller command to return
          a list of addresses and ports that are bound for listeners for a
          given connection type. This is useful when the user has configured
          "SocksPort auto" and the controller needs to know which port got
          chosen. Resolves another part of ticket 3076.
        - Have the controller interface give a more useful message than
          "Internal Error" in response to failed GETINFO requests.
        - Add a TIMEOUT_RATE keyword to the BUILDTIMEOUT_SET control port
          event, to give information on the current rate of circuit timeouts
          over our stored history.
        - The 'EXTENDCIRCUIT' control port command can now be used with
          a circ id of 0 and no path. This feature will cause Tor to build
          a new 'fast' general purpose circuit using its own path selection
          algorithms.
        - Added a BUILDTIMEOUT_SET controller event to describe changes
          to the circuit build timeout.
        - New controller command "getinfo config-text". It returns the
          contents that Tor would write if you send it a SAVECONF command,
          so the controller can write the file to disk itself.
    
      o Minor features (controller protocol):
        - Add a new ControlSocketsGroupWritable configuration option: when
          it is turned on, ControlSockets are group-writeable by the default
          group of the current user. Patch by Jérémy Bobbio; implements
          ticket 2972.
        - Tor now refuses to create a ControlSocket in a directory that is
          world-readable (or group-readable if ControlSocketsGroupWritable
          is 0). This is necessary because some operating systems do not
          enforce permissions on an AF_UNIX sockets. Permissions on the
          directory holding the socket, however, seems to work everywhere.
        - Warn when CookieAuthFileGroupReadable is set but CookieAuthFile is
          not. This would lead to a cookie that is still not group readable.
          Closes bug 1843. Suggested by katmagic.
        - Future-proof the controller protocol a bit by ignoring keyword
          arguments we do not recognize.
    
      o Minor features (more useful logging):
        - Revise most log messages that refer to nodes by nickname to
          instead use the "$key=nickname at address" format. This should be
          more useful, especially since nicknames are less and less likely
          to be unique. Resolves ticket 3045.
        - When an HTTPS proxy reports "403 Forbidden", we now explain
          what it means rather than calling it an unexpected status code.
          Closes bug 2503. Patch from Michael Yakubovich.
        - Rate-limit a warning about failures to download v2 networkstatus
          documents. Resolves part of bug 1352.
        - Rate-limit the "your application is giving Tor only an IP address"
          warning. Addresses bug 2000; bugfix on 0.0.8pre2.
        - Rate-limit "Failed to hand off onionskin" warnings.
        - When logging a rate-limited warning, we now mention how many messages
          got suppressed since the last warning.
        - Make the formerly ugly "2 unknown, 7 missing key, 0 good, 0 bad,
          2 no signature, 4 required" messages about consensus signatures
          easier to read, and make sure they get logged at the same severity
          as the messages explaining which keys are which. Fixes bug 1290.
        - Don't warn when we have a consensus that we can't verify because
          of missing certificates, unless those certificates are ones
          that we have been trying and failing to download. Fixes bug 1145.
    
      o Minor features (log domains):
        - Add documentation for configuring logging at different severities in
          different log domains. We've had this feature since 0.2.1.1-alpha,
          but for some reason it never made it into the manpage. Fixes
          bug 2215.
        - Make it simpler to specify "All log domains except for A and B".
          Previously you needed to say "[*,~A,~B]". Now you can just say
          "[~A,~B]".
        - Add a "LogMessageDomains 1" option to include the domains of log
          messages along with the messages. Without this, there's no way
          to use log domains without reading the source or doing a lot
          of guessing.
        - Add a new "Handshake" log domain for activities that happen
          during the TLS handshake.
    
      o Minor features (build process):
        - Make compilation with clang possible when using
          "--enable-gcc-warnings" by removing two warning options that clang
          hasn't implemented yet and by fixing a few warnings. Resolves
          ticket 2696.
        - Detect platforms that brokenly use a signed size_t, and refuse to
          build there. Found and analyzed by doorss and rransom.
        - Fix a bunch of compile warnings revealed by mingw with gcc 4.5.
          Resolves bug 2314.
        - Add support for statically linking zlib by specifying
          "--enable-static-zlib", to go with our support for statically
          linking openssl and libevent. Resolves bug 1358.
        - Instead of adding the svn revision to the Tor version string, report
          the git commit (when we're building from a git checkout).
        - Rename the "log.h" header to "torlog.h" so as to conflict with fewer
          system headers.
        - New --digests command-line switch to output the digests of the
          source files Tor was built with.
        - Generate our manpage and HTML documentation using Asciidoc. This
          change should make it easier to maintain the documentation, and
          produce nicer HTML. The build process fails if asciidoc cannot
          be found and building with asciidoc isn't disabled (via the
          "--disable-asciidoc" argument to ./configure. Skipping the manpage
          speeds up the build considerably.
    
      o Minor features (options / torrc):
        - Warn when the same option is provided more than once in a torrc
          file, on the command line, or in a single SETCONF statement, and
          the option is one that only accepts a single line. Closes bug 1384.
        - Warn when the user configures two HiddenServiceDir lines that point
          to the same directory. Bugfix on 0.0.6 (the version introducing
          HiddenServiceDir); fixes bug 3289.
        - Add new "perconnbwrate" and "perconnbwburst" consensus params to
          do individual connection-level rate limiting of clients. The torrc
          config options with the same names trump the consensus params, if
          both are present. Replaces the old "bwconnrate" and "bwconnburst"
          consensus params which were broken from 0.2.2.7-alpha through
          0.2.2.14-alpha. Closes bug 1947.
        - New config option "WarnUnsafeSocks 0" disables the warning that
          occurs whenever Tor receives a socks handshake using a version of
          the socks protocol that can only provide an IP address (rather
          than a hostname). Setups that do DNS locally over Tor are fine,
          and we shouldn't spam the logs in that case.
        - New config option "CircuitStreamTimeout" to override our internal
          timeout schedule for how many seconds until we detach a stream from
          a circuit and try a new circuit. If your network is particularly
          slow, you might want to set this to a number like 60.
        - New options for SafeLogging to allow scrubbing only log messages
          generated while acting as a relay. Specify "SafeLogging relay" if
          you want to ensure that only messages known to originate from
          client use of the Tor process will be logged unsafely.
        - Time and memory units in the configuration file can now be set to
          fractional units. For example, "2.5 GB" is now a valid value for
          AccountingMax.
        - Support line continuations in the torrc config file. If a line
          ends with a single backslash character, the newline is ignored, and
          the configuration value is treated as continuing on the next line.
          Resolves bug 1929.
    
      o Minor features (unit tests):
        - Revise our unit tests to use the "tinytest" framework, so we
          can run tests in their own processes, have smarter setup/teardown
          code, and so on. The unit test code has moved to its own
          subdirectory, and has been split into multiple modules.
        - Add a unit test for cross-platform directory-listing code.
        - Add some forgotten return value checks during unit tests. Found
          by coverity.
        - Use GetTempDir to find the proper temporary directory location on
          Windows when generating temporary files for the unit tests. Patch
          by Gisle Vanem.
    
      o Minor features (misc):
        - The "torify" script now uses torsocks where available.
        - Make Libevent log messages get delivered to controllers later,
          and not from inside the Libevent log handler. This prevents unsafe
          reentrant Libevent calls while still letting the log messages
          get through.
        - Certain Tor clients (such as those behind check.torproject.org) may
          want to fetch the consensus in an extra early manner. To enable this
          a user may now set FetchDirInfoExtraEarly to 1. This also depends on
          setting FetchDirInfoEarly to 1. Previous behavior will stay the same
          as only certain clients who must have this information sooner should
          set this option.
        - Expand homedirs passed to tor-checkkey. This should silence a
          coverity complaint about passing a user-supplied string into
          open() without checking it.
        - Make sure to disable DirPort if running as a bridge. DirPorts aren't
          used on bridges, and it makes bridge scanning somewhat easier.
        - Create the /var/run/tor directory on startup on OpenSUSE if it is
          not already created. Patch from Andreas Stieger. Fixes bug 2573.
    
      o Minor bugfixes (relays):
        - When a relay decides that its DNS is too broken for it to serve
          as an exit server, it advertised itself as a non-exit, but
          continued to act as an exit. This could create accidental
          partitioning opportunities for users. Instead, if a relay is
          going to advertise reject *:* as its exit policy, it should
          really act with exit policy "reject *:*". Fixes bug 2366.
          Bugfix on Tor 0.1.2.5-alpha. Bugfix by user "postman" on trac.
        - Publish a router descriptor even if generating an extra-info
          descriptor fails. Previously we would not publish a router
          descriptor without an extra-info descriptor; this can cause fast
          exit relays collecting exit-port statistics to drop from the
          consensus. Bugfix on 0.1.2.9-rc; fixes bug 2195.
        - When we're trying to guess whether we know our IP address as
          a relay, we would log various ways that we failed to guess
          our address, but never log that we ended up guessing it
          successfully. Now add a log line to help confused and anxious
          relay operators. Bugfix on 0.1.2.1-alpha; fixes bug 1534.
        - For bandwidth accounting, calculate our expected bandwidth rate
          based on the time during which we were active and not in
          soft-hibernation during the last interval. Previously, we were
          also considering the time spent in soft-hibernation. If this
          was a long time, we would wind up underestimating our bandwidth
          by a lot, and skewing our wakeup time towards the start of the
          accounting interval. Fixes bug 1789. Bugfix on 0.0.9pre5.
        - Demote a confusing TLS warning that relay operators might get when
          someone tries to talk to their ORPort. It is not the operator's
          fault, nor can they do anything about it. Fixes bug 1364; bugfix
          on 0.2.0.14-alpha.
        - Change "Application request when we're believed to be offline."
          notice to "Application request when we haven't used client
          functionality lately.", to clarify that it's not an error. Bugfix
          on 0.0.9.3; fixes bug 1222.
    
      o Minor bugfixes (bridges):
        - When a client starts or stops using bridges, never use a circuit
          that was built before the configuration change. This behavior could
          put at risk a user who uses bridges to ensure that her traffic
          only goes to the chosen addresses. Bugfix on 0.2.0.3-alpha; fixes
          bug 3200.
        - Do not reset the bridge descriptor download status every time we
          re-parse our configuration or get a configuration change. Fixes
          bug 3019; bugfix on 0.2.0.3-alpha.
        - Users couldn't configure a regular relay to be their bridge. It
          didn't work because when Tor fetched the bridge descriptor, it found
          that it already had it, and didn't realize that the purpose of the
          descriptor had changed. Now we replace routers with a purpose other
          than bridge with bridge descriptors when fetching them. Bugfix on
          0.1.1.9-alpha. Fixes bug 1776.
        - In the special case where you configure a public exit relay as your
          bridge, Tor would be willing to use that exit relay as the last
          hop in your circuit as well. Now we fail that circuit instead.
          Bugfix on 0.2.0.12-alpha. Fixes bug 2403. Reported by "piebeer".
    
      o Minor bugfixes (clients):
        - We now ask the other side of a stream (the client or the exit)
          for more data on that stream when the amount of queued data on
          that stream dips low enough. Previously, we wouldn't ask the
          other side for more data until either it sent us more data (which
          it wasn't supposed to do if it had exhausted its window!) or we
          had completely flushed all our queued data. This flow control fix
          should improve throughput. Fixes bug 2756; bugfix on the earliest
          released versions of Tor (svn commit r152).
        - When a client finds that an origin circuit has run out of 16-bit
          stream IDs, we now mark it as unusable for new streams. Previously,
          we would try to close the entire circuit. Bugfix on 0.0.6.
        - Make it explicit that we don't cannibalize one-hop circuits. This
          happens in the wild, but doesn't turn out to be a problem because
          we fortunately don't use those circuits. Many thanks to outofwords
          for the initial analysis and to swissknife who confirmed that
          two-hop circuits are actually created.
        - Resolve an edge case in path weighting that could make us misweight
          our relay selection. Fixes bug 1203; bugfix on 0.0.8rc1.
        - Make the DNSPort option work with libevent 2.x. Don't alter the
          behavior for libevent 1.x. Fixes bug 1143. Found by SwissTorExit.
    
      o Minor bugfixes (directory authorities):
        - Make directory authorities more accurate at recording when
          relays that have failed several reachability tests became
          unreachable, so we can provide more accuracy at assigning Stable,
          Guard, HSDir, etc flags. Bugfix on 0.2.0.6-alpha. Resolves bug 2716.
        - Directory authorities are now more robust to hops back in time
          when calculating router stability. Previously, if a run of uptime
          or downtime appeared to be negative, the calculation could give
          incorrect results. Bugfix on 0.2.0.6-alpha; noticed when fixing
          bug 1035.
        - Directory authorities will now attempt to download consensuses
          if their own efforts to make a live consensus have failed. This
          change means authorities that restart will fetch a valid
          consensus, and it means authorities that didn't agree with the
          current consensus will still fetch and serve it if it has enough
          signatures. Bugfix on 0.2.0.9-alpha; fixes bug 1300.
        - Never vote for a server as "Running" if we have a descriptor for
          it claiming to be hibernating, and that descriptor was published
          more recently than our last contact with the server. Bugfix on
          0.2.0.3-alpha; fixes bug 911.
        - Directory authorities no longer change their opinion of, or vote on,
          whether a router is Running, unless they have themselves been
          online long enough to have some idea. Bugfix on 0.2.0.6-alpha.
          Fixes bug 1023.
    
      o Minor bugfixes (hidden services):
        - Log malformed requests for rendezvous descriptors as protocol
          warnings, not warnings. Also, use a more informative log message
          in case someone sees it at log level warning without prior
          info-level messages. Fixes bug 2748; bugfix on 0.2.0.10-alpha.
        - Accept hidden service descriptors if we think we might be a hidden
          service directory, regardless of what our consensus says. This
          helps robustness, since clients and hidden services can sometimes
          have a more up-to-date view of the network consensus than we do,
          and if they think that the directory authorities list us a HSDir,
          we might actually be one. Related to bug 2732; bugfix on
          0.2.0.10-alpha.
        - Correct the warning displayed when a rendezvous descriptor exceeds
          the maximum size. Fixes bug 2750; bugfix on 0.2.1.5-alpha. Found by
          John Brooks.
        - Clients and hidden services now use HSDir-flagged relays for hidden
          service descriptor downloads and uploads even if the relays have no
          DirPort set and the client has disabled TunnelDirConns. This will
          eventually allow us to give the HSDir flag to relays with no
          DirPort. Fixes bug 2722; bugfix on 0.2.1.6-alpha.
        - Only limit the lengths of single HS descriptors, even when multiple
          HS descriptors are published to an HSDir relay in a single POST
          operation. Fixes bug 2948; bugfix on 0.2.1.5-alpha. Found by hsdir.
    
      o Minor bugfixes (controllers):
        - Allow GETINFO fingerprint to return a fingerprint even when
          we have not yet built a router descriptor. Fixes bug 3577;
          bugfix on 0.2.0.1-alpha.
        - Send a SUCCEEDED stream event to the controller when a reverse
          resolve succeeded. Fixes bug 3536; bugfix on 0.0.8pre1. Issue
          discovered by katmagic.
        - Remove a trailing asterisk from "exit-policy/default" in the
          output of the control port command "GETINFO info/names". Bugfix
          on 0.1.2.5-alpha.
        - Make the SIGNAL DUMP controller command work on FreeBSD. Fixes bug
          2917. Bugfix on 0.1.1.1-alpha.
        - When we restart our relay, we might get a successful connection
          from the outside before we've started our reachability tests,
          triggering a warning: "ORPort found reachable, but I have no
          routerinfo yet. Failing to inform controller of success." This
          bug was harmless unless Tor is running under a controller
          like Vidalia, in which case the controller would never get a
          REACHABILITY_SUCCEEDED status event. Bugfix on 0.1.2.6-alpha;
          fixes bug 1172.
        - When a controller changes TrackHostExits, remove mappings for
          hosts that should no longer have their exits tracked. Bugfix on
          0.1.0.1-rc.
        - When a controller changes VirtualAddrNetwork, remove any mappings
          for hosts that were automapped to the old network. Bugfix on
          0.1.1.19-rc.
        - When a controller changes one of the AutomapHosts* options, remove
          any mappings for hosts that should no longer be automapped. Bugfix
          on 0.2.0.1-alpha.
        - Fix an off-by-one error in calculating some controller command
          argument lengths. Fortunately, this mistake is harmless since
          the controller code does redundant NUL termination too. Found by
          boboper. Bugfix on 0.1.1.1-alpha.
        - Fix a bug in the controller interface where "GETINFO ns/asdaskljkl"
          would return "551 Internal error" rather than "552 Unrecognized key
          ns/asdaskljkl". Bugfix on 0.1.2.3-alpha.
        - Don't spam the controller with events when we have no file
          descriptors available. Bugfix on 0.2.1.5-alpha. (Rate-limiting
          for log messages was already solved from bug 748.)
        - Emit a GUARD DROPPED controller event for a case we missed.
        - Ensure DNS requests launched by "RESOLVE" commands from the
          controller respect the __LeaveStreamsUnattached setconf options. The
          same goes for requests launched via DNSPort or transparent
          proxying. Bugfix on 0.2.0.1-alpha; fixes bug 1525.
    
      o Minor bugfixes (config options):
        - Tor used to limit HttpProxyAuthenticator values to 48 characters.
          Change the limit to 512 characters by removing base64 newlines.
          Fixes bug 2752. Fix by Michael Yakubovich.
        - Complain if PublishServerDescriptor is given multiple arguments that
          include 0 or 1. This configuration will be rejected in the future.
          Bugfix on 0.2.0.1-alpha; closes bug 1107.
        - Disallow BridgeRelay 1 and ORPort 0 at once in the configuration.
          Bugfix on 0.2.0.13-alpha; closes bug 928.
    
      o Minor bugfixes (log subsystem fixes):
        - When unable to format an address as a string, report its value
          as "???" rather than reusing the last formatted address. Bugfix
          on 0.2.1.5-alpha.
        - Be more consistent in our treatment of file system paths. "~" should
          get expanded to the user's home directory in the Log config option.
          Fixes bug 2971; bugfix on 0.2.0.1-alpha, which introduced the
          feature for the -f and --DataDirectory options.
    
      o Minor bugfixes (memory management):
        - Don't stack-allocate the list of supplementary GIDs when we're
          about to log them. Stack-allocating NGROUPS_MAX gid_t elements
          could take up to 256K, which is way too much stack. Found by
          Coverity; CID #450. Bugfix on 0.2.1.7-alpha.
        - Save a couple bytes in memory allocation every time we escape
          certain characters in a string. Patch from Florian Zumbiehl.
    
      o Minor bugfixes (protocol correctness):
        - When checking for 1024-bit keys, check for 1024 bits, not 128
          bytes. This allows Tor to correctly discard keys of length 1017
          through 1023. Bugfix on 0.0.9pre5.
        - Require that introduction point keys and onion handshake keys
          have a public exponent of 65537. Starts to fix bug 3207; bugfix
          on 0.2.0.10-alpha.
        - Handle SOCKS messages longer than 128 bytes long correctly, rather
          than waiting forever for them to finish. Fixes bug 2330; bugfix
          on 0.2.0.16-alpha. Found by doorss.
        - Never relay a cell for a circuit we have already destroyed.
          Between marking a circuit as closeable and finally closing it,
          it may have been possible for a few queued cells to get relayed,
          even though they would have been immediately dropped by the next
          OR in the circuit. Fixes bug 1184; bugfix on 0.2.0.1-alpha.
        - Never queue a cell for a circuit that's already been marked
          for close.
        - Fix a spec conformance issue: the network-status-version token
          must be the first token in a v3 consensus or vote. Discovered by
          "parakeep". Bugfix on 0.2.0.3-alpha.
        - A networkstatus vote must contain exactly one signature. Spec
          conformance issue. Bugfix on 0.2.0.3-alpha.
        - When asked about a DNS record type we don't support via a
          client DNSPort, reply with NOTIMPL rather than an empty
          reply. Patch by intrigeri. Fixes bug 3369; bugfix on 2.0.1-alpha.
        - Make more fields in the controller protocol case-insensitive, since
          control-spec.txt said they were.
    
      o Minor bugfixes (log messages):
        - Fix a log message that said "bits" while displaying a value in
          bytes. Found by wanoskarnet. Fixes bug 3318; bugfix on
          0.2.0.1-alpha.
        - Downgrade "no current certificates known for authority" message from
          Notice to Info. Fixes bug 2899; bugfix on 0.2.0.10-alpha.
        - Correctly describe errors that occur when generating a TLS object.
          Previously we would attribute them to a failure while generating a
          TLS context. Patch by Robert Ransom. Bugfix on 0.1.0.4-rc; fixes
          bug 1994.
        - Fix an instance where a Tor directory mirror might accidentally
          log the IP address of a misbehaving Tor client. Bugfix on
          0.1.0.1-rc.
        - Stop logging at severity 'warn' when some other Tor client tries
          to establish a circuit with us using weak DH keys. It's a protocol
          violation, but that doesn't mean ordinary users need to hear about
          it. Fixes the bug part of bug 1114. Bugfix on 0.1.0.13.
        - If your relay can't keep up with the number of incoming create
          cells, it would log one warning per failure into your logs. Limit
          warnings to 1 per minute. Bugfix on 0.0.2pre10; fixes bug 1042.
    
      o Minor bugfixes (build fixes):
        - Fix warnings from GCC 4.6's "-Wunused-but-set-variable" option.
        - When warning about missing zlib development packages during compile,
          give the correct package names. Bugfix on 0.2.0.1-alpha.
        - Fix warnings that newer versions of autoconf produce during
          ./autogen.sh. These warnings appear to be harmless in our case,
          but they were extremely verbose. Fixes bug 2020.
        - Squash a compile warning on OpenBSD. Reported by Tas; fixes
          bug 1848.
    
      o Minor bugfixes (portability):
        - Write several files in text mode, on OSes that distinguish text
          mode from binary mode (namely, Windows). These files are:
          'buffer-stats', 'dirreq-stats', and 'entry-stats' on relays
          that collect those statistics; 'client_keys' and 'hostname' for
          hidden services that use authentication; and (in the tor-gencert
          utility) newly generated identity and signing keys. Previously,
          we wouldn't specify text mode or binary mode, leading to an
          assertion failure. Fixes bug 3607. Bugfix on 0.2.1.1-alpha (when
          the DirRecordUsageByCountry option which would have triggered
          the assertion failure was added), although this assertion failure
          would have occurred in tor-gencert on Windows in 0.2.0.1-alpha.
        - Selectively disable deprecation warnings on OS X because Lion
          started deprecating the shipped copy of openssl. Fixes bug 3643.
        - Use a wide type to hold sockets when built for 64-bit Windows.
          Fixes bug 3270.
        - Fix an issue that prevented static linking of libevent on
          some platforms (notably Linux). Fixes bug 2698; bugfix on 0.2.1.23,
          where we introduced the "--with-static-libevent" configure option.
        - Fix a bug with our locking implementation on Windows that couldn't
          correctly detect when a file was already locked. Fixes bug 2504,
          bugfix on 0.2.1.6-alpha.
        - Build correctly on OSX with zlib 1.2.4 and higher with all warnings
          enabled.
        - Fix IPv6-related connect() failures on some platforms (BSD, OS X).
          Bugfix on 0.2.0.3-alpha; fixes first part of bug 2660. Patch by
          "piebeer".
    
      o Minor bugfixes (code correctness):
        - Always NUL-terminate the sun_path field of a sockaddr_un before
          passing it to the kernel. (Not a security issue: kernels are
          smart enough to reject bad sockaddr_uns.) Found by Coverity;
          CID #428. Bugfix on Tor 0.2.0.3-alpha.
        - Make connection_printf_to_buf()'s behavior sane. Its callers
          expect it to emit a CRLF iff the format string ends with CRLF;
          it actually emitted a CRLF iff (a) the format string ended with
          CRLF or (b) the resulting string was over 1023 characters long or
          (c) the format string did not end with CRLF *and* the resulting
          string was 1021 characters long or longer. Bugfix on 0.1.1.9-alpha;
          fixes part of bug 3407.
        - Make send_control_event_impl()'s behavior sane. Its callers
          expect it to always emit a CRLF at the end of the string; it
          might have emitted extra control characters as well. Bugfix on
          0.1.1.9-alpha; fixes another part of bug 3407.
        - Make crypto_rand_int() check the value of its input correctly.
          Previously, it accepted values up to UINT_MAX, but could return a
          negative number if given a value above INT_MAX+1. Found by George
          Kadianakis. Fixes bug 3306; bugfix on 0.2.2pre14.
        - Fix a potential null-pointer dereference while computing a
          consensus. Bugfix on 0.2.0.3-alpha, found with the help of
          clang's analyzer.
        - If we fail to compute the identity digest of a v3 legacy keypair,
          warn, and don't use a buffer-full of junk instead. Bugfix on
          0.2.1.1-alpha; fixes bug 3106.
        - Resolve an untriggerable issue in smartlist_string_num_isin(),
          where if the function had ever in the future been used to check
          for the presence of a too-large number, it would have given an
          incorrect result. (Fortunately, we only used it for 16-bit
          values.) Fixes bug 3175; bugfix on 0.1.0.1-rc.
        - Be more careful about reporting the correct error from a failed
          connect() system call. Under some circumstances, it was possible to
          look at an incorrect value for errno when sending the end reason.
          Bugfix on 0.1.0.1-rc.
        - Correctly handle an "impossible" overflow cases in connection byte
          counting, where we write or read more than 4GB on an edge connection
          in a single second. Bugfix on 0.1.2.8-beta.
        - Avoid a double mark-for-free warning when failing to attach a
          transparent proxy connection. Bugfix on 0.1.2.1-alpha. Fixes
          bug 2279.
        - Correctly detect failure to allocate an OpenSSL BIO. Fixes bug 2378;
          found by "cypherpunks". This bug was introduced before the first
          Tor release, in svn commit r110.
        - Fix a bug in bandwidth history state parsing that could have been
          triggered if a future version of Tor ever changed the timing
          granularity at which bandwidth history is measured. Bugfix on
          Tor 0.1.1.11-alpha.
        - Add assertions to check for overflow in arguments to
          base32_encode() and base32_decode(); fix a signed-unsigned
          comparison there too. These bugs are not actually reachable in Tor,
          but it's good to prevent future errors too. Found by doorss.
        - Avoid a bogus overlapped memcpy in tor_addr_copy(). Reported by
          "memcpyfail".
        - Set target port in get_interface_address6() correctly. Bugfix
          on 0.1.1.4-alpha and 0.2.0.3-alpha; fixes second part of bug 2660.
        - Fix an impossible-to-actually-trigger buffer overflow in relay
          descriptor generation. Bugfix on 0.1.0.15.
        - Fix numerous small code-flaws found by Coverity Scan Rung 3.
    
      o Minor bugfixes (code improvements):
        - After we free an internal connection structure, overwrite it
          with a different memory value than we use for overwriting a freed
          internal circuit structure. Should help with debugging. Suggested
          by bug 1055.
        - If OpenSSL fails to make a duplicate of a private or public key, log
          an error message and try to exit cleanly. May help with debugging
          if bug 1209 ever remanifests.
        - Some options used different conventions for uppercasing of acronyms
          when comparing manpage and source. Fix those in favor of the
          manpage, as it makes sense to capitalize acronyms.
        - Take a first step towards making or.h smaller by splitting out
          function definitions for all source files in src/or/. Leave
          structures and defines in or.h for now.
        - Remove a few dead assignments during router parsing. Found by
          coverity.
        - Don't use 1-bit wide signed bit fields. Found by coverity.
        - Avoid signed/unsigned comparisons by making SIZE_T_CEILING unsigned.
          None of the cases where we did this before were wrong, but by making
          this change we avoid warnings. Fixes bug 2475; bugfix on 0.2.1.28.
        - The memarea code now uses a sentinel value at the end of each area
          to make sure nothing writes beyond the end of an area. This might
          help debug some conceivable causes of bug 930.
        - Always treat failure to allocate an RSA key as an unrecoverable
          allocation error.
        - Add some more defensive programming for architectures that can't
          handle unaligned integer accesses. We don't know of any actual bugs
          right now, but that's the best time to fix them. Fixes bug 1943.
    
      o Minor bugfixes (misc):
        - Fix a rare bug in rend_fn unit tests: we would fail a test when
          a randomly generated port is 0. Diagnosed by Matt Edman. Bugfix
          on 0.2.0.10-alpha; fixes bug 1808.
        - Where available, use Libevent 2.0's periodic timers so that our
          once-per-second cleanup code gets called even more closely to
          once per second than it would otherwise. Fixes bug 943.
        - Ignore OutboundBindAddress when connecting to localhost.
          Connections to localhost need to come _from_ localhost, or else
          local servers (like DNS and outgoing HTTP/SOCKS proxies) will often
          refuse to listen.
        - Update our OpenSSL 0.9.8l fix so that it works with OpenSSL 0.9.8m
          too.
        - If any of the v3 certs we download are unparseable, we should
          actually notice the failure so we don't retry indefinitely. Bugfix
          on 0.2.0.x; reported by "rotator".
        - When Tor fails to parse a descriptor of any kind, dump it to disk.
          Might help diagnosing bug 1051.
        - Make our 'torify' script more portable; if we have only one of
          'torsocks' or 'tsocks' installed, don't complain to the user;
          and explain our warning about tsocks better.
        - Fix some urls in the exit notice file and make it XHTML1.1 strict
          compliant. Based on a patch from Christian Kujau.
    
      o Documentation changes:
        - Modernize the doxygen configuration file slightly. Fixes bug 2707.
        - Resolve all doxygen warnings except those for missing documentation.
          Fixes bug 2705.
        - Add doxygen documentation for more functions, fields, and types.
        - Convert the HACKING file to asciidoc, and add a few new sections
          to it, explaining how we use Git, how we make changelogs, and
          what should go in a patch.
        - Document the default socks host and port (127.0.0.1:9050) for
          tor-resolve.
        - Removed some unnecessary files from the source distribution. The
          AUTHORS file has now been merged into the people page on the
          website. The roadmaps and design doc can now be found in the
          projects directory in svn.
    
      o Deprecated and removed features (config):
        - Remove the torrc.complete file. It hasn't been kept up to date
          and users will have better luck checking out the manpage.
        - Remove the HSAuthorityRecordStats option that version 0 hidden
          service authorities could use to track statistics of overall v0
          hidden service usage.
        - Remove the obsolete "NoPublish" option; it has been flagged
          as obsolete and has produced a warning since 0.1.1.18-rc.
        - Caches no longer download and serve v2 networkstatus documents
          unless FetchV2Networkstatus flag is set: these documents haven't
          haven't been used by clients or relays since 0.2.0.x. Resolves
          bug 3022.
    
      o Deprecated and removed features (controller):
        - The controller no longer accepts the old obsolete "addr-mappings/"
          or "unregistered-servers-" GETINFO values.
        - The EXTENDED_EVENTS and VERBOSE_NAMES controller features are now
          always on; using them is necessary for correct forward-compatible
          controllers.
    
      o Deprecated and removed features (misc):
        - Hidden services no longer publish version 0 descriptors, and clients
          do not request or use version 0 descriptors. However, the old hidden
          service authorities still accept and serve version 0 descriptors
          when contacted by older hidden services/clients.
        - Remove undocumented option "-F" from tor-resolve: it hasn't done
          anything since 0.2.1.16-rc.
        - Remove everything related to building the expert bundle for OS X.
          It has confused many users, doesn't work right on OS X 10.6,
          and is hard to get rid of once installed. Resolves bug 1274.
        - Remove support for .noconnect style addresses. Nobody was using
          them, and they provided another avenue for detecting Tor users
          via application-level web tricks.
        - When we fixed bug 1038 we had to put in a restriction not to send
          RELAY_EARLY cells on rend circuits. This was necessary as long
          as relays using Tor 0.2.1.3-alpha through 0.2.1.18-alpha were
          active. Now remove this obsolete check. Resolves bug 2081.
        - Remove workaround code to handle directory responses from servers
          that had bug 539 (they would send HTTP status 503 responses _and_
          send a body too). Since only server versions before
          0.2.0.16-alpha/0.1.2.19 were affected, there is no longer reason to
          keep the workaround in place.
        - Remove the old 'fuzzy time' logic. It was supposed to be used for
          handling calculations where we have a known amount of clock skew and
          an allowed amount of unknown skew. But we only used it in three
          places, and we never adjusted the known/unknown skew values. This is
          still something we might want to do someday, but if we do, we'll
          want to do it differently.
        - Remove the "--enable-iphone" option to ./configure. According to
          reports from Marco Bonetti, Tor builds fine without any special
          tweaking on recent iPhone SDK versions.
    
    
    Changes in version 0.2.1.30 - 2011-02-23
      Tor 0.2.1.30 fixes a variety of less critical bugs. The main other
      change is a slight tweak to Tor's TLS handshake that makes relays
      and bridges that run this new version reachable from Iran again.
      We don't expect this tweak will win the arms race long-term, but it
      buys us time until we roll out a better solution.
    
      o Major bugfixes:
        - Stop sending a CLOCK_SKEW controller status event whenever
          we fetch directory information from a relay that has a wrong clock.
          Instead, only inform the controller when it's a trusted authority
          that claims our clock is wrong. Bugfix on 0.1.2.6-alpha; fixes
          the rest of bug 1074.
        - Fix a bounds-checking error that could allow an attacker to
          remotely crash a directory authority. Bugfix on 0.2.1.5-alpha.
          Found by "piebeer".
        - If relays set RelayBandwidthBurst but not RelayBandwidthRate,
          Tor would ignore their RelayBandwidthBurst setting,
          potentially using more bandwidth than expected. Bugfix on
          0.2.0.1-alpha. Reported by Paul Wouters. Fixes bug 2470.
        - Ignore and warn if the user mistakenly sets "PublishServerDescriptor
          hidserv" in her torrc. The 'hidserv' argument never controlled
          publication of hidden service descriptors. Bugfix on 0.2.0.1-alpha.
    
      o Minor features:
        - Adjust our TLS Diffie-Hellman parameters to match those used by
          Apache's mod_ssl.
        - Update to the February 1 2011 Maxmind GeoLite Country database.
    
      o Minor bugfixes:
        - Check for and reject overly long directory certificates and
          directory tokens before they have a chance to hit any assertions.
          Bugfix on 0.2.1.28. Found by "doorss".
        - Bring the logic that gathers routerinfos and assesses the
          acceptability of circuits into line. This prevents a Tor OP from
          getting locked in a cycle of choosing its local OR as an exit for a
          path (due to a .exit request) and then rejecting the circuit because
          its OR is not listed yet. It also prevents Tor clients from using an
          OR running in the same instance as an exit (due to a .exit request)
          if the OR does not meet the same requirements expected of an OR
          running elsewhere. Fixes bug 1859; bugfix on 0.1.0.1-rc.
    
      o Packaging changes:
        - Stop shipping the Tor specs files and development proposal documents
          in the tarball. They are now in a separate git repository at
          git://git.torproject.org/torspec.git
        - Do not include Git version tags as though they are SVN tags when
          generating a tarball from inside a repository that has switched
          between branches. Bugfix on 0.2.1.15-rc; fixes bug 2402.
    
    
    Changes in version 0.2.1.29 - 2011-01-15
      Tor 0.2.1.29 continues our recent code security audit work. The main
      fix resolves a remote heap overflow vulnerability that can allow remote
      code execution. Other fixes address a variety of assert and crash bugs,
      most of which we think are hard to exploit remotely.
    
      o Major bugfixes (security):
        - Fix a heap overflow bug where an adversary could cause heap
          corruption. This bug probably allows remote code execution
          attacks. Reported by "debuger". Fixes CVE-2011-0427. Bugfix on
          0.1.2.10-rc.
        - Prevent a denial-of-service attack by disallowing any
          zlib-compressed data whose compression factor is implausibly
          high. Fixes part of bug 2324; reported by "doorss".
        - Zero out a few more keys in memory before freeing them. Fixes
          bug 2384 and part of bug 2385. These key instances found by
          "cypherpunks", based on Andrew Case's report about being able
          to find sensitive data in Tor's memory space if you have enough
          permissions. Bugfix on 0.0.2pre9.
    
      o Major bugfixes (crashes):
        - Prevent calls to Libevent from inside Libevent log handlers.
          This had potential to cause a nasty set of crashes, especially
          if running Libevent with debug logging enabled, and running
          Tor with a controller watching for low-severity log messages.
          Bugfix on 0.1.0.2-rc. Fixes bug 2190.
        - Add a check for SIZE_T_MAX to tor_realloc() to try to avoid
          underflow errors there too. Fixes the other part of bug 2324.
        - Fix a bug where we would assert if we ever had a
          cached-descriptors.new file (or another file read directly into
          memory) of exactly SIZE_T_CEILING bytes. Fixes bug 2326; bugfix
          on 0.2.1.25. Found by doorss.
        - Fix some potential asserts and parsing issues with grossly
          malformed router caches. Fixes bug 2352; bugfix on Tor 0.2.1.27.
          Found by doorss.
    
      o Minor bugfixes (other):
        - Fix a bug with handling misformed replies to reverse DNS lookup
          requests in DNSPort. Bugfix on Tor 0.2.0.1-alpha. Related to a
          bug reported by doorss.
        - Fix compilation on mingw when a pthreads compatibility library
          has been installed. (We don't want to use it, so we shouldn't
          be including pthread.h.) Fixes bug 2313; bugfix on 0.1.0.1-rc.
        - Fix a bug where we would declare that we had run out of virtual
          addresses when the address space was only half-exhausted. Bugfix
          on 0.1.2.1-alpha.
        - Correctly handle the case where AutomapHostsOnResolve is set but
          no virtual addresses are available. Fixes bug 2328; bugfix on
          0.1.2.1-alpha. Bug found by doorss.
        - Correctly handle wrapping around when we run out of virtual
          address space. Found by cypherpunks; bugfix on 0.2.0.5-alpha.
    
      o Minor features:
        - Update to the January 1 2011 Maxmind GeoLite Country database.
        - Introduce output size checks on all of our decryption functions.
    
      o Build changes:
        - Tor does not build packages correctly with Automake 1.6 and earlier;
          added a check to Makefile.am to make sure that we're building with
          Automake 1.7 or later.
        - The 0.2.1.28 tarball was missing src/common/OpenBSD_malloc_Linux.c
          because we built it with a too-old version of automake. Thus that
          release broke ./configure --enable-openbsd-malloc, which is popular
          among really fast exit relays on Linux.
    
    
    Changes in version 0.2.1.28 - 2010-12-17
      Tor 0.2.1.28 does some code cleanup to reduce the risk of remotely
      exploitable bugs. We also took this opportunity to change the IP address
      for one of our directory authorities, and to update the geoip database
      we ship.
    
      o Major bugfixes:
        - Fix a remotely exploitable bug that could be used to crash instances
          of Tor remotely by overflowing on the heap. Remote-code execution
          hasn't been confirmed, but can't be ruled out. Everyone should
          upgrade. Bugfix on the 0.1.1 series and later.
    
      o Directory authority changes:
        - Change IP address and ports for gabelmoo (v3 directory authority).
    
      o Minor features:
        - Update to the December 1 2010 Maxmind GeoLite Country database.
    
    
    Changes in version 0.2.1.27 - 2010-11-23
      Yet another OpenSSL security patch broke its compatibility with Tor:
      Tor 0.2.1.27 makes relays work with openssl 0.9.8p and 1.0.0.b. We
      also took this opportunity to fix several crash bugs, integrate a new
      directory authority, and update the bundled GeoIP database.
    
      o Major bugfixes:
        - Resolve an incompatibility with OpenSSL 0.9.8p and OpenSSL 1.0.0b:
          No longer set the tlsext_host_name extension on server SSL objects;
          but continue to set it on client SSL objects. Our goal in setting
          it was to imitate a browser, not a vhosting server. Fixes bug 2204;
          bugfix on 0.2.1.1-alpha.
        - Do not log messages to the controller while shrinking buffer
          freelists. Doing so would sometimes make the controller connection
          try to allocate a buffer chunk, which would mess up the internals
          of the freelist and cause an assertion failure. Fixes bug 1125;
          fixed by Robert Ransom. Bugfix on 0.2.0.16-alpha.
        - Learn our external IP address when we're a relay or bridge, even if
          we set PublishServerDescriptor to 0. Bugfix on 0.2.0.3-alpha,
          where we introduced bridge relays that don't need to publish to
          be useful. Fixes bug 2050.
        - Do even more to reject (and not just ignore) annotations on
          router descriptors received anywhere but from the cache. Previously
          we would ignore such annotations at first, but cache them to disk
          anyway. Bugfix on 0.2.0.8-alpha. Found by piebeer.
        - When you're using bridges and your network goes away and your
          bridges get marked as down, recover when you attempt a new socks
          connection (if the network is back), rather than waiting up to an
          hour to try fetching new descriptors for your bridges. Bugfix on
          0.2.0.3-alpha; fixes bug 1981.
    
      o Major features:
        - Move to the November 2010 Maxmind GeoLite country db (rather
          than the June 2009 ip-to-country GeoIP db) for our statistics that
          count how many users relays are seeing from each country. Now we'll
          have more accurate data, especially for many African countries.
    
      o New directory authorities:
        - Set up maatuska (run by Linus Nordberg) as the eighth v3 directory
          authority.
    
      o Minor bugfixes:
        - Fix an assertion failure that could occur in directory caches or
          bridge users when using a very short voting interval on a testing
          network. Diagnosed by Robert Hogan. Fixes bug 1141; bugfix on
          0.2.0.8-alpha.
        - Enforce multiplicity rules when parsing annotations. Bugfix on
          0.2.0.8-alpha. Found by piebeer.
        - Allow handshaking OR connections to take a full KeepalivePeriod
          seconds to handshake. Previously, we would close them after
          IDLE_OR_CONN_TIMEOUT (180) seconds, the same timeout as if they
          were open. Bugfix on 0.2.1.26; fixes bug 1840. Thanks to mingw-san
          for analysis help.
        - When building with --enable-gcc-warnings on OpenBSD, disable
          warnings in system headers. This makes --enable-gcc-warnings
          pass on OpenBSD 4.8.
    
      o Minor features:
        - Exit nodes didn't recognize EHOSTUNREACH as a plausible error code,
          and so sent back END_STREAM_REASON_MISC. Clients now recognize a new
          stream ending reason for this case: END_STREAM_REASON_NOROUTE.
          Servers can start sending this code when enough clients recognize
          it. Bugfix on 0.1.0.1-rc; fixes part of bug 1793.
        - Build correctly on mingw with more recent versions of OpenSSL 0.9.8.
          Patch from mingw-san.
    
      o Removed files:
        - Remove the old debian/ directory from the main Tor distribution.
          The official Tor-for-debian git repository lives at the URL
          https://git.torproject.org/debian/tor.git
        - Stop shipping the old doc/website/ directory in the tarball. We
          changed the website format in late 2010, and what we shipped in
          0.2.1.26 really wasn't that useful anyway.
    
    
    Changes in version 0.2.1.26 - 2010-05-02
      Tor 0.2.1.26 addresses the recent connection and memory overload
      problems we've been seeing on relays, especially relays with their
      DirPort open. If your relay has been crashing, or you turned it off
      because it used too many resources, give this release a try.
    
      This release also fixes yet another instance of broken OpenSSL libraries
      that was causing some relays to drop out of the consensus.
    
      o Major bugfixes:
        - Teach relays to defend themselves from connection overload. Relays
          now close idle circuits early if it looks like they were intended
          for directory fetches. Relays are also more aggressive about closing
          TLS connections that have no circuits on them. Such circuits are
          unlikely to be re-used, and tens of thousands of them were piling
          up at the fast relays, causing the relays to run out of sockets
          and memory. Bugfix on 0.2.0.22-rc (where clients started tunneling
          their directory fetches over TLS).
        - Fix SSL renegotiation behavior on OpenSSL versions like on Centos
          that claim to be earlier than 0.9.8m, but which have in reality
          backported huge swaths of 0.9.8m or 0.9.8n renegotiation
          behavior. Possible fix for some cases of bug 1346.
        - Directory mirrors were fetching relay descriptors only from v2
          directory authorities, rather than v3 authorities like they should.
          Only 2 v2 authorities remain (compared to 7 v3 authorities), leading
          to a serious bottleneck. Bugfix on 0.2.0.9-alpha. Fixes bug 1324.
    
      o Minor bugfixes:
        - Finally get rid of the deprecated and now harmful notion of "clique
          mode", where directory authorities maintain TLS connections to
          every other relay.
    
      o Testsuite fixes:
        - In the util/threads test, no longer free the test_mutex before all
          worker threads have finished. Bugfix on 0.2.1.6-alpha.
        - The master thread could starve the worker threads quite badly on
          certain systems, causing them to run only partially in the allowed
          window. This resulted in test failures. Now the master thread sleeps
          occasionally for a few microseconds while the two worker-threads
          compete for the mutex. Bugfix on 0.2.0.1-alpha.
    
    
    Changes in version 0.2.1.25 - 2010-03-16
      Tor 0.2.1.25 fixes a regression introduced in 0.2.1.23 that could
      prevent relays from guessing their IP address correctly. It also fixes
      several minor potential security bugs.
    
      o Major bugfixes:
        - Fix a regression from our patch for bug 1244 that caused relays
          to guess their IP address incorrectly if they didn't set Address
          in their torrc and/or their address fails to resolve. Bugfix on
          0.2.1.23; fixes bug 1269.
        - When freeing a session key, zero it out completely. We only zeroed
          the first ptrsize bytes. Bugfix on 0.0.2pre8. Discovered and
          patched by ekir. Fixes bug 1254.
    
      o Minor bugfixes:
        - Fix a dereference-then-NULL-check sequence when publishing
          descriptors. Bugfix on 0.2.1.5-alpha. Discovered by ekir; fixes
          bug 1255.
        - Fix another dereference-then-NULL-check sequence. Bugfix on
          0.2.1.14-rc. Discovered by ekir; fixes bug 1256.
        - Make sure we treat potentially not NUL-terminated strings correctly.
          Bugfix on 0.1.1.13-alpha. Discovered by rieo; fixes bug 1257.
    
    
    Changes in version 0.2.1.24 - 2010-02-21
      Tor 0.2.1.24 makes Tor work again on the latest OS X -- this time
      for sure!
    
      o Minor bugfixes:
        - Work correctly out-of-the-box with even more vendor-patched versions
          of OpenSSL. In particular, make it so Debian and OS X don't need
          customized patches to run/build.
    
    
    Changes in version 0.2.1.23 - 2010-02-13
      Tor 0.2.1.23 fixes a huge client-side performance bug, makes Tor work
      again on the latest OS X, and updates the location of a directory
      authority.
    
      o Major bugfixes (performance):
        - We were selecting our guards uniformly at random, and then weighting
          which of our guards we'd use uniformly at random. This imbalance
          meant that Tor clients were severely limited on throughput (and
          probably latency too) by the first hop in their circuit. Now we
          select guards weighted by currently advertised bandwidth. We also
          automatically discard guards picked using the old algorithm. Fixes
          bug 1217; bugfix on 0.2.1.3-alpha. Found by Mike Perry.
    
      o Major bugfixes:
        - Make Tor work again on the latest OS X: when deciding whether to
          use strange flags to turn TLS renegotiation on, detect the OpenSSL
          version at run-time, not compile time. We need to do this because
          Apple doesn't update its dev-tools headers when it updates its
          libraries in a security patch.
        - Fix a potential buffer overflow in lookup_last_hid_serv_request()
          that could happen on 32-bit platforms with 64-bit time_t. Also fix
          a memory leak when requesting a hidden service descriptor we've
          requested before. Fixes bug 1242, bugfix on 0.2.0.18-alpha. Found
          by aakova.
    
      o Minor bugfixes:
        - Refactor resolve_my_address() to not use gethostbyname() anymore.
          Fixes bug 1244; bugfix on 0.0.2pre25. Reported by Mike Mestnik.
    
      o Minor features:
        - Avoid a mad rush at the beginning of each month when each client
          rotates half of its guards. Instead we spread the rotation out
          throughout the month, but we still avoid leaving a precise timestamp
          in the state file about when we first picked the guard. Improves
          over the behavior introduced in 0.1.2.17.
    
    
    Changes in version 0.2.1.22 - 2010-01-19
      Tor 0.2.1.22 fixes a critical privacy problem in bridge directory
      authorities -- it would tell you its whole history of bridge descriptors
      if you make the right directory request. This stable update also
      rotates two of the seven v3 directory authority keys and locations.
    
      o Directory authority changes:
        - Rotate keys (both v3 identity and relay identity) for moria1
          and gabelmoo.
    
      o Major bugfixes:
        - Stop bridge directory authorities from answering dbg-stability.txt
          directory queries, which would let people fetch a list of all
          bridge identities they track. Bugfix on 0.2.1.6-alpha.
    
    
    Changes in version 0.2.1.21 - 2009-12-21
      Tor 0.2.1.21 fixes an incompatibility with the most recent OpenSSL
      library. If you use Tor on Linux / Unix and you're getting SSL
      renegotiation errors, upgrading should help. We also recommend an
      upgrade if you're an exit relay.
    
      o Major bugfixes:
        - Work around a security feature in OpenSSL 0.9.8l that prevents our
          handshake from working unless we explicitly tell OpenSSL that we
          are using SSL renegotiation safely. We are, of course, but OpenSSL
          0.9.8l won't work unless we say we are.
        - Avoid crashing if the client is trying to upload many bytes and the
          circuit gets torn down at the same time, or if the flip side
          happens on the exit relay. Bugfix on 0.2.0.1-alpha; fixes bug 1150.
    
      o Minor bugfixes:
        - Do not refuse to learn about authority certs and v2 networkstatus
          documents that are older than the latest consensus. This bug might
          have degraded client bootstrapping. Bugfix on 0.2.0.10-alpha.
          Spotted and fixed by xmux.
        - Fix a couple of very-hard-to-trigger memory leaks, and one hard-to-
          trigger platform-specific option misparsing case found by Coverity
          Scan.
        - Fix a compilation warning on Fedora 12 by removing an impossible-to-
          trigger assert. Fixes bug 1173.
    
    
    Changes in version 0.2.1.20 - 2009-10-15
      Tor 0.2.1.20 fixes a crash bug when you're accessing many hidden
      services at once, prepares for more performance improvements, and
      fixes a bunch of smaller bugs.
    
      The Windows and OS X bundles also include a more recent Vidalia,
      and switch from Privoxy to Polipo.
    
      The OS X installers are now drag and drop. It's best to un-install
      Tor/Vidalia and then install this new bundle, rather than upgrade. If
      you want to upgrade, you'll need to update the paths for Tor and Polipo
      in the Vidalia Settings window.
    
      o Major bugfixes:
        - Send circuit or stream sendme cells when our window has decreased
          by 100 cells, not when it has decreased by 101 cells. Bug uncovered
          by Karsten when testing the "reduce circuit window" performance
          patch. Bugfix on the 54th commit on Tor -- from July 2002,
          before the release of Tor 0.0.0. This is the new winner of the
          oldest-bug prize.
        - Fix a remotely triggerable memory leak when a consensus document
          contains more than one signature from the same voter. Bugfix on
          0.2.0.3-alpha.
        - Avoid segfault in rare cases when finishing an introduction circuit
          as a client and finding out that we don't have an introduction key
          for it. Fixes bug 1073. Reported by Aaron Swartz.
    
      o Major features:
        - Tor now reads the "circwindow" parameter out of the consensus,
          and uses that value for its circuit package window rather than the
          default of 1000 cells. Begins the implementation of proposal 168.
    
      o New directory authorities:
        - Set up urras (run by Jacob Appelbaum) as the seventh v3 directory
          authority.
        - Move moria1 and tonga to alternate IP addresses.
    
      o Minor bugfixes:
        - Fix a signed/unsigned compile warning in 0.2.1.19.
        - Fix possible segmentation fault on directory authorities. Bugfix on
          0.2.1.14-rc.
        - Fix an extremely rare infinite recursion bug that could occur if
          we tried to log a message after shutting down the log subsystem.
          Found by Matt Edman. Bugfix on 0.2.0.16-alpha.
        - Fix an obscure bug where hidden services on 64-bit big-endian
          systems might mis-read the timestamp in v3 introduce cells, and
          refuse to connect back to the client. Discovered by "rotor".
          Bugfix on 0.2.1.6-alpha.
        - We were triggering a CLOCK_SKEW controller status event whenever
          we connect via the v2 connection protocol to any relay that has
          a wrong clock. Instead, we should only inform the controller when
          it's a trusted authority that claims our clock is wrong. Bugfix
          on 0.2.0.20-rc; starts to fix bug 1074. Reported by SwissTorExit.
        - We were telling the controller about CHECKING_REACHABILITY and
          REACHABILITY_FAILED status events whenever we launch a testing
          circuit or notice that one has failed. Instead, only tell the
          controller when we want to inform the user of overall success or
          overall failure. Bugfix on 0.1.2.6-alpha. Fixes bug 1075. Reported
          by SwissTorExit.
        - Don't warn when we're using a circuit that ends with a node
          excluded in ExcludeExitNodes, but the circuit is not used to access
          the outside world. This should help fix bug 1090. Bugfix on
          0.2.1.6-alpha.
        - Work around a small memory leak in some versions of OpenSSL that
          stopped the memory used by the hostname TLS extension from being
          freed.
    
      o Minor features:
        - Add a "getinfo status/accepted-server-descriptor" controller
          command, which is the recommended way for controllers to learn
          whether our server descriptor has been successfully received by at
          least on directory authority. Un-recommend good-server-descriptor
          getinfo and status events until we have a better design for them.
    
    
    Changes in version 0.2.1.19 - 2009-07-28
      Tor 0.2.1.19 fixes a major bug with accessing and providing hidden
      services.
    
      o Major bugfixes:
        - Make accessing hidden services on 0.2.1.x work right again.
          Bugfix on 0.2.1.3-alpha; workaround for bug 1038. Diagnosis and
          part of patch provided by "optimist".
    
      o Minor features:
        - When a relay/bridge is writing out its identity key fingerprint to
          the "fingerprint" file and to its logs, write it without spaces. Now
          it will look like the fingerprints in our bridges documentation,
          and confuse fewer users.
    
      o Minor bugfixes:
        - Relays no longer publish a new server descriptor if they change
          their MaxAdvertisedBandwidth config option but it doesn't end up
          changing their advertised bandwidth numbers. Bugfix on 0.2.0.28-rc;
          fixes bug 1026. Patch from Sebastian.
        - Avoid leaking memory every time we get a create cell but we have
          so many already queued that we refuse it. Bugfix on 0.2.0.19-alpha;
          fixes bug 1034. Reported by BarkerJr.
    
    
    Changes in version 0.2.1.18 - 2009-07-24
      Tor 0.2.1.18 lays the foundations for performance improvements,
      adds status events to help users diagnose bootstrap problems, adds
      optional authentication/authorization for hidden services, fixes a
      variety of potential anonymity problems, and includes a huge pile of
      other features and bug fixes.
    
      o Major features (clients):
        - Start sending "bootstrap phase" status events to the controller,
          so it can keep the user informed of progress fetching directory
          information and establishing circuits. Also inform the controller
          if we think we're stuck at a particular bootstrap phase. Implements
          proposal 137.
        - Clients replace entry guards that were chosen more than a few months
          ago. This change should significantly improve client performance,
          especially once more people upgrade, since relays that have been
          a guard for a long time are currently overloaded.
        - Network status consensus documents and votes now contain bandwidth
          information for each relay. Clients use the bandwidth values
          in the consensus, rather than the bandwidth values in each
          relay descriptor. This approach opens the door to more accurate
          bandwidth estimates once the directory authorities start doing
          active measurements. Implements part of proposal 141.
    
      o Major features (relays):
        - Disable and refactor some debugging checks that forced a linear scan
          over the whole server-side DNS cache. These accounted for over 50%
          of CPU time on a relatively busy exit node's gprof profile. Also,
          disable some debugging checks that appeared in exit node profile
          data. Found by Jacob.
        - New DirPortFrontPage option that takes an html file and publishes
          it as "/" on the DirPort. Now relay operators can provide a
          disclaimer without needing to set up a separate webserver. There's
          a sample disclaimer in contrib/tor-exit-notice.html.
    
      o Major features (hidden services):
        - Make it possible to build hidden services that only certain clients
          are allowed to connect to. This is enforced at several points,
          so that unauthorized clients are unable to send INTRODUCE cells
          to the service, or even (depending on the type of authentication)
          to learn introduction points. This feature raises the bar for
          certain kinds of active attacks against hidden services. Design
          and code by Karsten Loesing. Implements proposal 121.
        - Relays now store and serve v2 hidden service descriptors by default,
          i.e., the new default value for HidServDirectoryV2 is 1. This is
          the last step in proposal 114, which aims to make hidden service
          lookups more reliable.
    
      o Major features (path selection):
        - ExitNodes and Exclude*Nodes config options now allow you to restrict
          by country code ("{US}") or IP address or address pattern
          ("255.128.0.0/16"). Patch from Robert Hogan. It still needs some
          refinement to decide what config options should take priority if
          you ask to both use a particular node and exclude it.
    
      o Major features (misc):
        - When building a consensus, do not include routers that are down.
          This cuts down 30% to 40% on consensus size. Implements proposal
          138.
        - New TestingTorNetwork config option to allow adjustment of
          previously constant values that could slow bootstrapping. Implements
          proposal 135. Patch from Karsten.
        - Convert many internal address representations to optionally hold
          IPv6 addresses. Generate and accept IPv6 addresses in many protocol
          elements. Make resolver code handle nameservers located at IPv6
          addresses.
        - More work on making our TLS handshake blend in: modify the list
          of ciphers advertised by OpenSSL in client mode to even more
          closely resemble a common web browser. We cheat a little so that
          we can advertise ciphers that the locally installed OpenSSL doesn't
          know about.
        - Use the TLS1 hostname extension to more closely resemble browser
          behavior.
    
      o Security fixes (anonymity/entropy):
        - Never use a connection with a mismatched address to extend a
          circuit, unless that connection is canonical. A canonical
          connection is one whose address is authenticated by the router's
          identity key, either in a NETINFO cell or in a router descriptor.
        - Implement most of proposal 110: The first K cells to be sent
          along a circuit are marked as special "early" cells; only K "early"
          cells will be allowed. Once this code is universal, we can block
          certain kinds of denial-of-service attack by requiring that EXTEND
          commands must be sent using an "early" cell.
        - Resume using OpenSSL's RAND_poll() for better (and more portable)
          cross-platform entropy collection again. We used to use it, then
          stopped using it because of a bug that could crash systems that
          called RAND_poll when they had a lot of fds open. It looks like the
          bug got fixed in late 2006. Our new behavior is to call RAND_poll()
          at startup, and to call RAND_poll() when we reseed later only if
          we have a non-buggy OpenSSL version.
        - When the client is choosing entry guards, now it selects at most
          one guard from a given relay family. Otherwise we could end up with
          all of our entry points into the network run by the same operator.
          Suggested by Camilo Viecco. Fix on 0.1.1.11-alpha.
        - Do not use or believe expired v3 authority certificates. Patch
          from Karsten. Bugfix in 0.2.0.x. Fixes bug 851.
        - Drop begin cells to a hidden service if they come from the middle
          of a circuit. Patch from lark.
        - When we erroneously receive two EXTEND cells for the same circuit
          ID on the same connection, drop the second. Patch from lark.
        - Authorities now vote for the Stable flag for any router whose
          weighted MTBF is at least 5 days, regardless of the mean MTBF.
        - Clients now never report any stream end reason except 'MISC'.
          Implements proposal 148.
    
      o Major bugfixes (crashes):
        - Parse dates and IPv4 addresses in a locale- and libc-independent
          manner, to avoid platform-dependent behavior on malformed input.
        - Fix a crash that occurs on exit nodes when a nameserver request
          timed out. Bugfix on 0.1.2.1-alpha; our CLEAR debugging code had
          been suppressing the bug since 0.1.2.10-alpha. Partial fix for
          bug 929.
        - Do not assume that a stack-allocated character array will be
          64-bit aligned on platforms that demand that uint64_t access is
          aligned. Possible fix for bug 604.
        - Resolve a very rare crash bug that could occur when the user forced
          a nameserver reconfiguration during the middle of a nameserver
          probe. Fixes bug 526. Bugfix on 0.1.2.1-alpha.
        - Avoid a "0 divided by 0" calculation when calculating router uptime
          at directory authorities. Bugfix on 0.2.0.8-alpha.
        - Fix an assertion bug in parsing policy-related options; possible fix
          for bug 811.
        - Rate-limit too-many-sockets messages: when they happen, they happen
          a lot and end up filling up the disk. Resolves bug 748.
        - Fix a race condition that could cause crashes or memory corruption
          when running as a server with a controller listening for log
          messages.
        - Avoid crashing when we have a policy specified in a DirPolicy or
          SocksPolicy or ReachableAddresses option with ports set on it,
          and we re-load the policy. May fix bug 996.
        - Fix an assertion failure on 64-bit platforms when we allocated
          memory right up to the end of a memarea, then realigned the memory
          one step beyond the end. Fixes a possible cause of bug 930.
        - Protect the count of open sockets with a mutex, so we can't
          corrupt it when two threads are closing or opening sockets at once.
          Fix for bug 939. Bugfix on 0.2.0.1-alpha.
    
      o Major bugfixes (clients):
        - Discard router descriptors as we load them if they are more than
          five days old. Otherwise if Tor is off for a long time and then
          starts with cached descriptors, it will try to use the onion keys
          in those obsolete descriptors when building circuits. Fixes bug 887.
        - When we choose to abandon a new entry guard because we think our
          older ones might be better, close any circuits pending on that
          new entry guard connection. This fix should make us recover much
          faster when our network is down and then comes back. Bugfix on
          0.1.2.8-beta; found by lodger.
        - When Tor clients restart after 1-5 days, they discard all their
          cached descriptors as too old, but they still use the cached
          consensus document. This approach is good for robustness, but
          bad for performance: since they don't know any bandwidths, they
          end up choosing at random rather than weighting their choice by
          speed. Fixed by the above feature of putting bandwidths in the
          consensus.
    
      o Major bugfixes (relays):
        - Relays were falling out of the networkstatus consensus for
          part of a day if they changed their local config but the
          authorities discarded their new descriptor as "not sufficiently
          different". Now directory authorities accept a descriptor as changed
          if BandwidthRate or BandwidthBurst changed. Partial fix for bug 962;
          patch by Sebastian.
        - Ensure that two circuits can never exist on the same connection
          with the same circuit ID, even if one is marked for close. This
          is conceivably a bugfix for bug 779; fixes a bug on 0.1.0.4-rc.
        - Directory authorities were neglecting to mark relays down in their
          internal histories if the relays fall off the routerlist without
          ever being found unreachable. So there were relays in the histories
          that haven't been seen for eight months, and are listed as being
          up for eight months. This wreaked havoc on the "median wfu" and
          "median mtbf" calculations, in turn making Guard and Stable flags
          wrong, hurting network performance. Fixes bugs 696 and 969. Bugfix
          on 0.2.0.6-alpha.
    
      o Major bugfixes (hidden services):
        - When establishing a hidden service, introduction points that
          originate from cannibalized circuits were completely ignored
          and not included in rendezvous service descriptors. This might
          have been another reason for delay in making a hidden service
          available. Bugfix from long ago (0.0.9.x?)
    
      o Major bugfixes (memory and resource management):
        - Fixed some memory leaks -- some quite frequent, some almost
          impossible to trigger -- based on results from Coverity.
        - Speed up parsing and cut down on memory fragmentation by using
          stack-style allocations for parsing directory objects. Previously,
          this accounted for over 40% of allocations from within Tor's code
          on a typical directory cache.
        - Use a Bloom filter rather than a digest-based set to track which
          descriptors we need to keep around when we're cleaning out old
          router descriptors. This speeds up the computation significantly,
          and may reduce fragmentation.
    
      o New/changed config options:
        - Now NodeFamily and MyFamily config options allow spaces in
          identity fingerprints, so it's easier to paste them in.
          Suggested by Lucky Green.
        - Allow ports 465 and 587 in the default exit policy again. We had
          rejected them in 0.1.0.15, because back in 2005 they were commonly
          misconfigured and ended up as spam targets. We hear they are better
          locked down these days.
        - Make TrackHostExit mappings expire a while after their last use, not
          after their creation. Patch from Robert Hogan.
        - Add an ExcludeExitNodes option so users can list a set of nodes
          that should be be excluded from the exit node position, but
          allowed elsewhere. Implements proposal 151.
        - New --hush command-line option similar to --quiet. While --quiet
          disables all logging to the console on startup, --hush limits the
          output to messages of warning and error severity.
        - New configure/torrc options (--enable-geoip-stats,
          DirRecordUsageByCountry) to record how many IPs we've served
          directory info to in each country code, how many status documents
          total we've sent to each country code, and what share of the total
          directory requests we should expect to see.
        - Make outbound DNS packets respect the OutboundBindAddress setting.
          Fixes the bug part of bug 798. Bugfix on 0.1.2.2-alpha.
        - Allow separate log levels to be configured for different logging
          domains. For example, this allows one to log all notices, warnings,
          or errors, plus all memory management messages of level debug or
          higher, with: Log [MM] debug-err [*] notice-err file /var/log/tor.
        - Update to the "June 3 2009" ip-to-country file.
    
      o Minor features (relays):
        - Raise the minimum rate limiting to be a relay from 20000 bytes
          to 20480 bytes (aka 20KB/s), to match our documentation. Also
          update directory authorities so they always assign the Fast flag
          to relays with 20KB/s of capacity. Now people running relays won't
          suddenly find themselves not seeing any use, if the network gets
          faster on average.
        - If we're a relay and we change our IP address, be more verbose
          about the reason that made us change. Should help track down
          further bugs for relays on dynamic IP addresses.
        - Exit servers can now answer resolve requests for ip6.arpa addresses.
        - Implement most of Proposal 152: allow specialized servers to permit
          single-hop circuits, and clients to use those servers to build
          single-hop circuits when using a specialized controller. Patch
          from Josh Albrecht. Resolves feature request 768.
        - When relays do their initial bandwidth measurement, don't limit
          to just our entry guards for the test circuits. Otherwise we tend
          to have multiple test circuits going through a single entry guard,
          which makes our bandwidth test less accurate. Fixes part of bug 654;
          patch contributed by Josh Albrecht.
    
      o Minor features (directory authorities):
        - Try not to open more than one descriptor-downloading connection
          to an authority at once. This should reduce load on directory
          authorities. Fixes bug 366.
        - Add cross-certification to newly generated certificates, so that
          a signing key is enough information to look up a certificate. Start
          serving certificates by <identity digest, signing key digest>
          pairs. Implements proposal 157.
        - When a directory authority downloads a descriptor that it then
          immediately rejects, do not retry downloading it right away. Should
          save some bandwidth on authorities. Fix for bug 888. Patch by
          Sebastian Hahn.
        - Directory authorities now serve a /tor/dbg-stability.txt URL to
          help debug WFU and MTBF calculations.
        - In directory authorities' approved-routers files, allow
          fingerprints with or without space.
    
      o Minor features (directory mirrors):
        - When a download gets us zero good descriptors, do not notify
          Tor that new directory information has arrived.
        - Servers support a new URL scheme for consensus downloads that
          allows the client to specify which authorities are trusted.
          The server then only sends the consensus if the client will trust
          it. Otherwise a 404 error is sent back. Clients use this
          new scheme when the server supports it (meaning it's running
          0.2.1.1-alpha or later). Implements proposal 134.
    
      o Minor features (bridges):
        - If the bridge config line doesn't specify a port, assume 443.
          This makes bridge lines a bit smaller and easier for users to
          understand.
        - If we're using bridges and our network goes away, be more willing
          to forgive our bridges and try again when we get an application
          request.
    
      o Minor features (hidden services):
        - When the client launches an introduction circuit, retry with a
          new circuit after 30 seconds rather than 60 seconds.
        - Launch a second client-side introduction circuit in parallel
          after a delay of 15 seconds (based on work by Christian Wilms).
        - Hidden services start out building five intro circuits rather
          than three, and when the first three finish they publish a service
          descriptor using those. Now we publish our service descriptor much
          faster after restart.
        - Drop the requirement to have an open dir port for storing and
          serving v2 hidden service descriptors.
    
      o Minor features (build and packaging):
        - On Linux, use the prctl call to re-enable core dumps when the User
          option is set.
        - Try to make sure that the version of Libevent we're running with
          is binary-compatible with the one we built with. May address bug
          897 and others.
        - Add a new --enable-local-appdata configuration switch to change
          the default location of the datadir on win32 from APPDATA to
          LOCAL_APPDATA. In the future, we should migrate to LOCAL_APPDATA
          entirely. Patch from coderman.
        - Build correctly against versions of OpenSSL 0.9.8 or later that
          are built without support for deprecated functions.
        - On platforms with a maximum syslog string length, truncate syslog
          messages to that length ourselves, rather than relying on the
          system to do it for us.
        - Automatically detect MacOSX versions earlier than 10.4.0, and
          disable kqueue from inside Tor when running with these versions.
          We previously did this from the startup script, but that was no
          help to people who didn't use the startup script. Resolves bug 863.
        - Build correctly when configured to build outside the main source
          path. Patch from Michael Gold.
        - Disable GCC's strict alias optimization by default, to avoid the
          likelihood of its introducing subtle bugs whenever our code violates
          the letter of C99's alias rules.
        - Change the contrib/tor.logrotate script so it makes the new
          logs as "_tor:_tor" rather than the default, which is generally
          "root:wheel". Fixes bug 676, reported by Serge Koksharov.
        - Change our header file guard macros to be less likely to conflict
          with system headers. Adam Langley noticed that we were conflicting
          with log.h on Android.
        - Add a couple of extra warnings to --enable-gcc-warnings for GCC 4.3,
          and stop using a warning that had become unfixably verbose under
          GCC 4.3.
        - Use a lockfile to make sure that two Tor processes are not
          simultaneously running with the same datadir.
        - Allow OpenSSL to use dynamic locks if it wants.
        - Add LIBS=-lrt to Makefile.am so the Tor RPMs use a static libevent.
    
      o Minor features (controllers):
        - When generating circuit events with verbose nicknames for
          controllers, try harder to look up nicknames for routers on a
          circuit. (Previously, we would look in the router descriptors we had
          for nicknames, but not in the consensus.) Partial fix for bug 941.
        - New controller event NEWCONSENSUS that lists the networkstatus
          lines for every recommended relay. Now controllers like Torflow
          can keep up-to-date on which relays they should be using.
        - New controller event "clients_seen" to report a geoip-based summary
          of which countries we've seen clients from recently. Now controllers
          like Vidalia can show bridge operators that they're actually making
          a difference.
        - Add a 'getinfo status/clients-seen' controller command, in case
          controllers want to hear clients_seen events but connect late.
        - New CONSENSUS_ARRIVED event to note when a new consensus has
          been fetched and validated.
        - Add an internal-use-only __ReloadTorrcOnSIGHUP option for
          controllers to prevent SIGHUP from reloading the configuration.
          Fixes bug 856.
        - Return circuit purposes in response to GETINFO circuit-status.
          Fixes bug 858.
        - Serve the latest v3 networkstatus consensus via the control
          port. Use "getinfo dir/status-vote/current/consensus" to fetch it.
        - Add a "GETINFO /status/bootstrap-phase" controller option, so the
          controller can query our current bootstrap state in case it attaches
          partway through and wants to catch up.
        - Provide circuit purposes along with circuit events to the controller.
    
      o Minor features (tools):
        - Do not have tor-resolve automatically refuse all .onion addresses;
          if AutomapHostsOnResolve is set in your torrc, this will work fine.
        - Add a -p option to tor-resolve for specifying the SOCKS port: some
          people find host:port too confusing.
        - Print the SOCKS5 error message string as well as the error code
          when a tor-resolve request fails. Patch from Jacob.
    
      o Minor bugfixes (memory and resource management):
        - Clients no longer cache certificates for authorities they do not
          recognize. Bugfix on 0.2.0.9-alpha.
        - Do not use C's stdio library for writing to log files. This will
          improve logging performance by a minute amount, and will stop
          leaking fds when our disk is full. Fixes bug 861.
        - Stop erroneous use of O_APPEND in cases where we did not in fact
          want to re-seek to the end of a file before every last write().
        - Fix a small alignment and memory-wasting bug on buffer chunks.
          Spotted by rovv.
        - Add a malloc_good_size implementation to OpenBSD_malloc_linux.c,
          to avoid unused RAM in buffer chunks and memory pools.
        - Reduce the default smartlist size from 32 to 16; it turns out that
          most smartlists hold around 8-12 elements tops.
        - Make dumpstats() log the fullness and size of openssl-internal
          buffers.
        - If the user has applied the experimental SSL_MODE_RELEASE_BUFFERS
          patch to their OpenSSL, turn it on to save memory on servers. This
          patch will (with any luck) get included in a mainline distribution
          before too long.
        - Fix a memory leak when v3 directory authorities load their keys
          and cert from disk. Bugfix on 0.2.0.1-alpha.
        - Stop using malloc_usable_size() to use more area than we had
          actually allocated: it was safe, but made valgrind really unhappy.
        - Make the assert_circuit_ok() function work correctly on circuits that
          have already been marked for close.
        - Fix uninitialized size field for memory area allocation: may improve
          memory performance during directory parsing.
    
      o Minor bugfixes (clients):
        - Stop reloading the router list from disk for no reason when we
          run out of reachable directory mirrors. Once upon a time reloading
          it would set the 'is_running' flag back to 1 for them. It hasn't
          done that for a long time.
        - When we had picked an exit node for a connection, but marked it as
          "optional", and it turned out we had no onion key for the exit,
          stop wanting that exit and try again. This situation may not
          be possible now, but will probably become feasible with proposal
          158. Spotted by rovv. Fixes another case of bug 752.
        - Fix a bug in address parsing that was preventing bridges or hidden
          service targets from being at IPv6 addresses.
        - Do not remove routers as too old if we do not have any consensus
          document. Bugfix on 0.2.0.7-alpha.
        - When an exit relay resolves a stream address to a local IP address,
          do not just keep retrying that same exit relay over and
          over. Instead, just close the stream. Addresses bug 872. Bugfix
          on 0.2.0.32. Patch from rovv.
        - Made Tor a little less aggressive about deleting expired
          certificates. Partial fix for bug 854.
        - Treat duplicate certificate fetches as failures, so that we do
          not try to re-fetch an expired certificate over and over and over.
        - Do not say we're fetching a certificate when we'll in fact skip it
          because of a pending download.
        - If we have correct permissions on $datadir, we complain to stdout
          and fail to start. But dangerous permissions on
          $datadir/cached-status/ would cause us to open a log and complain
          there. Now complain to stdout and fail to start in both cases. Fixes
          bug 820, reported by seeess.
    
      o Minor bugfixes (bridges):
        - When we made bridge authorities stop serving bridge descriptors over
          unencrypted links, we also broke DirPort reachability testing for
          bridges. So bridges with a non-zero DirPort were printing spurious
          warns to their logs. Bugfix on 0.2.0.16-alpha. Fixes bug 709.
        - Don't allow a bridge to publish its router descriptor to a
          non-bridge directory authority. Fixes part of bug 932.
        - When we change to or from being a bridge, reset our counts of
          client usage by country. Fixes bug 932.
    
      o Minor bugfixes (relays):
        - Log correct error messages for DNS-related network errors on
          Windows.
        - Actually return -1 in the error case for read_bandwidth_usage().
          Harmless bug, since we currently don't care about the return value
          anywhere. Bugfix on 0.2.0.9-alpha.
        - Provide a more useful log message if bug 977 (related to buffer
          freelists) ever reappears, and do not crash right away.
        - We were already rejecting relay begin cells with destination port
          of 0. Now also reject extend cells with destination port or address
          of 0. Suggested by lark.
        - When we can't transmit a DNS request due to a network error, retry
          it after a while, and eventually transmit a failing response to
          the RESOLVED cell. Bugfix on 0.1.2.5-alpha.
        - Solve a bug that kept hardware crypto acceleration from getting
          enabled when accounting was turned on. Fixes bug 907. Bugfix on
          0.0.9pre6.
        - When a canonical connection appears later in our internal list
          than a noncanonical one for a given OR ID, always use the
          canonical one. Bugfix on 0.2.0.12-alpha. Fixes bug 805.
          Spotted by rovv.
        - Avoid some nasty corner cases in the logic for marking connections
          as too old or obsolete or noncanonical for circuits. Partial
          bugfix on bug 891.
        - Fix another interesting corner-case of bug 891 spotted by rovv:
          Previously, if two hosts had different amounts of clock drift, and
          one of them created a new connection with just the wrong timing,
          the other might decide to deprecate the new connection erroneously.
          Bugfix on 0.1.1.13-alpha.
        - If one win32 nameserver fails to get added, continue adding the
          rest, and don't automatically fail.
        - Fix a bug where an unreachable relay would establish enough
          reachability testing circuits to do a bandwidth test -- if
          we already have a connection to the middle hop of the testing
          circuit, then it could establish the last hop by using the existing
          connection. Bugfix on 0.1.2.2-alpha, exposed when we made testing
          circuits no longer use entry guards in 0.2.1.3-alpha.
    
      o Minor bugfixes (directory authorities):
        - Limit uploaded directory documents to be 16M rather than 500K.
          The directory authorities were refusing v3 consensus votes from
          other authorities, since the votes are now 504K. Fixes bug 959;
          bugfix on 0.0.2pre17 (where we raised it from 50K to 500K ;).
        - Directory authorities should never send a 503 "busy" response to
          requests for votes or keys. Bugfix on 0.2.0.8-alpha; exposed by
          bug 959.
        - Fix code so authorities _actually_ send back X-Descriptor-Not-New
          headers. Bugfix on 0.2.0.10-alpha.
    
      o Minor bugfixes (hidden services):
        - When we can't find an intro key for a v2 hidden service descriptor,
          fall back to the v0 hidden service descriptor and log a bug message.
          Workaround for bug 1024.
        - In very rare situations new hidden service descriptors were
          published earlier than 30 seconds after the last change to the
          service. (We currently think that a hidden service descriptor
          that's been stable for 30 seconds is worth publishing.)
        - If a hidden service sends us an END cell, do not consider
          retrying the connection; just close it. Patch from rovv.
        - If we are not using BEGIN_DIR cells, don't attempt to contact hidden
          service directories if they have no advertised dir port. Bugfix
          on 0.2.0.10-alpha.
    
      o Minor bugfixes (tools):
        - In the torify(1) manpage, mention that tsocks will leak your
          DNS requests.
    
      o Minor bugfixes (controllers):
        - If the controller claimed responsibility for a stream, but that
          stream never finished making its connection, it would live
          forever in circuit_wait state. Now we close it after SocksTimeout
          seconds. Bugfix on 0.1.2.7-alpha; reported by Mike Perry.
        - Make DNS resolved controller events into "CLOSED", not
          "FAILED". Bugfix on 0.1.2.5-alpha. Fix by Robert Hogan. Resolves
          bug 807.
        - The control port would close the connection before flushing long
          replies, such as the network consensus, if a QUIT command was issued
          before the reply had completed. Now, the control port flushes all
          pending replies before closing the connection. Also fix a spurious
          warning when a QUIT command is issued after a malformed or rejected
          AUTHENTICATE command, but before the connection was closed. Patch
          by Marcus Griep. Fixes bugs 1015 and 1016.
        - Fix a bug that made stream bandwidth get misreported to the
          controller.
    
      o Deprecated and removed features:
        - The old "tor --version --version" command, which would print out
          the subversion "Id" of most of the source files, is now removed. It
          turned out to be less useful than we'd expected, and harder to
          maintain.
        - RedirectExits has been removed. It was deprecated since
          0.2.0.3-alpha.
        - Finally remove deprecated "EXTENDED_FORMAT" controller feature. It
          has been called EXTENDED_EVENTS since 0.1.2.4-alpha.
        - Cell pools are now always enabled; --disable-cell-pools is ignored.
        - Directory mirrors no longer fetch the v1 directory or
          running-routers files. They are obsolete, and nobody asks for them
          anymore. This is the first step to making v1 authorities obsolete.
        - Take out the TestVia config option, since it was a workaround for
          a bug that was fixed in Tor 0.1.1.21.
        - Mark RendNodes, RendExcludeNodes, HiddenServiceNodes, and
          HiddenServiceExcludeNodes as obsolete: they never worked properly,
          and nobody seems to be using them. Fixes bug 754. Bugfix on
          0.1.0.1-rc. Patch from Christian Wilms.
        - Remove all backward-compatibility code for relays running
          versions of Tor so old that they no longer work at all on the
          Tor network.
    
      o Code simplifications and refactoring:
        - Tool-assisted documentation cleanup. Nearly every function or
          static variable in Tor should have its own documentation now.
        - Rename the confusing or_is_obsolete field to the more appropriate
          is_bad_for_new_circs, and move it to or_connection_t where it
          belongs.
        - Move edge-only flags from connection_t to edge_connection_t: not
          only is this better coding, but on machines of plausible alignment,
          it should save 4-8 bytes per connection_t. "Every little bit helps."
        - Rename ServerDNSAllowBrokenResolvConf to ServerDNSAllowBrokenConfig
          for consistency; keep old option working for backward compatibility.
        - Simplify the code for finding connections to use for a circuit.
        - Revise the connection_new functions so that a more typesafe variant
          exists. This will work better with Coverity, and let us find any
          actual mistakes we're making here.
        - Refactor unit testing logic so that dmalloc can be used sensibly
          with unit tests to check for memory leaks.
        - Move all hidden-service related fields from connection and circuit
          structure to substructures: this way they won't eat so much memory.
        - Squeeze 2-5% out of client performance (according to oprofile) by
          improving the implementation of some policy-manipulation functions.
        - Change the implementation of ExcludeNodes and ExcludeExitNodes to
          be more efficient. Formerly it was quadratic in the number of
          servers; now it should be linear. Fixes bug 509.
        - Save 16-22 bytes per open circuit by moving the n_addr, n_port,
          and n_conn_id_digest fields into a separate structure that's
          only needed when the circuit has not yet attached to an n_conn.
        - Optimize out calls to time(NULL) that occur for every IO operation,
          or for every cell. On systems like Windows where time() is a
          slow syscall, this fix will be slightly helpful.
    
    
    Changes in version 0.2.0.35 - 2009-06-24
      o Security fix:
        - Avoid crashing in the presence of certain malformed descriptors.
          Found by lark, and by automated fuzzing.
        - Fix an edge case where a malicious exit relay could convince a
          controller that the client's DNS question resolves to an internal IP
          address. Bug found and fixed by "optimist"; bugfix on 0.1.2.8-beta.
    
      o Major bugfixes:
        - Finally fix the bug where dynamic-IP relays disappear when their
          IP address changes: directory mirrors were mistakenly telling
          them their old address if they asked via begin_dir, so they
          never got an accurate answer about their new address, so they
          just vanished after a day. For belt-and-suspenders, relays that
          don't set Address in their config now avoid using begin_dir for
          all direct connections. Should fix bugs 827, 883, and 900.
        - Fix a timing-dependent, allocator-dependent, DNS-related crash bug
          that would occur on some exit nodes when DNS failures and timeouts
          occurred in certain patterns. Fix for bug 957.
    
      o Minor bugfixes:
        - When starting with a cache over a few days old, do not leak
          memory for the obsolete router descriptors in it. Bugfix on
          0.2.0.33; fixes bug 672.
        - Hidden service clients didn't use a cached service descriptor that
          was older than 15 minutes, but wouldn't fetch a new one either,
          because there was already one in the cache. Now, fetch a v2
          descriptor unless the same descriptor was added to the cache within
          the last 15 minutes. Fixes bug 997; reported by Marcus Griep.
    
    
    Changes in version 0.2.0.34 - 2009-02-08
      Tor 0.2.0.34 features several more security-related fixes. You should
      upgrade, especially if you run an exit relay (remote crash) or a
      directory authority (remote infinite loop), or you're on an older
      (pre-XP) or not-recently-patched Windows (remote exploit).
    
      This release marks end-of-life for Tor 0.1.2.x. Those Tor versions
      have many known flaws, and nobody should be using them. You should
      upgrade. If you're using a Linux or BSD and its packages are obsolete,
      stop using those packages and upgrade anyway.
    
      o Security fixes:
        - Fix an infinite-loop bug on handling corrupt votes under certain
          circumstances. Bugfix on 0.2.0.8-alpha.
        - Fix a temporary DoS vulnerability that could be performed by
          a directory mirror. Bugfix on 0.2.0.9-alpha; reported by lark.
        - Avoid a potential crash on exit nodes when processing malformed
          input. Remote DoS opportunity. Bugfix on 0.2.0.33.
        - Do not accept incomplete ipv4 addresses (like 192.168.0) as valid.
          Spec conformance issue. Bugfix on Tor 0.0.2pre27.
    
      o Minor bugfixes:
        - Fix compilation on systems where time_t is a 64-bit integer.
          Patch from Matthias Drochner.
        - Don't consider expiring already-closed client connections. Fixes
          bug 893. Bugfix on 0.0.2pre20.
    
    
    Changes in version 0.2.0.33 - 2009-01-21
      Tor 0.2.0.33 fixes a variety of bugs that were making relays less
      useful to users. It also finally fixes a bug where a relay or client
      that's been off for many days would take a long time to bootstrap.
    
      This update also fixes an important security-related bug reported by
      Ilja van Sprundel. You should upgrade. (We'll send out more details
      about the bug once people have had some time to upgrade.)
    
      o Security fixes:
        - Fix a heap-corruption bug that may be remotely triggerable on
          some platforms. Reported by Ilja van Sprundel.
    
      o Major bugfixes:
        - When a stream at an exit relay is in state "resolving" or
          "connecting" and it receives an "end" relay cell, the exit relay
          would silently ignore the end cell and not close the stream. If
          the client never closes the circuit, then the exit relay never
          closes the TCP connection. Bug introduced in Tor 0.1.2.1-alpha;
          reported by "wood".
        - When sending CREATED cells back for a given circuit, use a 64-bit
          connection ID to find the right connection, rather than an addr:port
          combination. Now that we can have multiple OR connections between
          the same ORs, it is no longer possible to use addr:port to uniquely
          identify a connection.
        - Bridge relays that had DirPort set to 0 would stop fetching
          descriptors shortly after startup, and then briefly resume
          after a new bandwidth test and/or after publishing a new bridge
          descriptor. Bridge users that try to bootstrap from them would
          get a recent networkstatus but would get descriptors from up to
          18 hours earlier, meaning most of the descriptors were obsolete
          already. Reported by Tas; bugfix on 0.2.0.13-alpha.
        - Prevent bridge relays from serving their 'extrainfo' document
          to anybody who asks, now that extrainfo docs include potentially
          sensitive aggregated client geoip summaries. Bugfix on
          0.2.0.13-alpha.
        - If the cached networkstatus consensus is more than five days old,
          discard it rather than trying to use it. In theory it could be
          useful because it lists alternate directory mirrors, but in practice
          it just means we spend many minutes trying directory mirrors that
          are long gone from the network. Also discard router descriptors as
          we load them if they are more than five days old, since the onion
          key is probably wrong by now. Bugfix on 0.2.0.x. Fixes bug 887.
    
      o Minor bugfixes:
        - Do not mark smartlist_bsearch_idx() function as ATTR_PURE. This bug
          could make gcc generate non-functional binary search code. Bugfix
          on 0.2.0.10-alpha.
        - Build correctly on platforms without socklen_t.
        - Compile without warnings on solaris.
        - Avoid potential crash on internal error during signature collection.
          Fixes bug 864. Patch from rovv.
        - Correct handling of possible malformed authority signing key
          certificates with internal signature types. Fixes bug 880.
          Bugfix on 0.2.0.3-alpha.
        - Fix a hard-to-trigger resource leak when logging credential status.
          CID 349.
        - When we can't initialize DNS because the network is down, do not
          automatically stop Tor from starting. Instead, we retry failed
          dns_init() every 10 minutes, and change the exit policy to reject
          *:* until one succeeds. Fixes bug 691.
        - Use 64 bits instead of 32 bits for connection identifiers used with
          the controller protocol, to greatly reduce risk of identifier reuse.
        - When we're choosing an exit node for a circuit, and we have
          no pending streams, choose a good general exit rather than one that
          supports "all the pending streams". Bugfix on 0.1.1.x. Fix by rovv.
        - Fix another case of assuming, when a specific exit is requested,
          that we know more than the user about what hosts it allows.
          Fixes one case of bug 752. Patch from rovv.
        - Clip the MaxCircuitDirtiness config option to a minimum of 10
          seconds. Warn the user if lower values are given in the
          configuration. Bugfix on 0.1.0.1-rc. Patch by Sebastian.
        - Clip the CircuitBuildTimeout to a minimum of 30 seconds. Warn the
          user if lower values are given in the configuration. Bugfix on
          0.1.1.17-rc. Patch by Sebastian.
        - Fix a memory leak when we decline to add a v2 rendezvous descriptor to
          the cache because we already had a v0 descriptor with the same ID.
          Bugfix on 0.2.0.18-alpha.
        - Fix a race condition when freeing keys shared between main thread
          and CPU workers that could result in a memory leak. Bugfix on
          0.1.0.1-rc. Fixes bug 889.
        - Send a valid END cell back when a client tries to connect to a
          nonexistent hidden service port. Bugfix on 0.1.2.15. Fixes bug
          840. Patch from rovv.
        - Check which hops rendezvous stream cells are associated with to
          prevent possible guess-the-streamid injection attacks from
          intermediate hops. Fixes another case of bug 446. Based on patch
          from rovv.
        - If a broken client asks a non-exit router to connect somewhere,
          do not even do the DNS lookup before rejecting the connection.
          Fixes another case of bug 619. Patch from rovv.
        - When a relay gets a create cell it can't decrypt (e.g. because it's
          using the wrong onion key), we were dropping it and letting the
          client time out. Now actually answer with a destroy cell. Fixes
          bug 904. Bugfix on 0.0.2pre8.
    
      o Minor bugfixes (hidden services):
        - Do not throw away existing introduction points on SIGHUP. Bugfix on
          0.0.6pre1. Patch by Karsten. Fixes bug 874.
    
      o Minor features:
        - Report the case where all signatures in a detached set are rejected
          differently than the case where there is an error handling the
          detached set.
        - When we realize that another process has modified our cached
          descriptors, print out a more useful error message rather than
          triggering an assertion. Fixes bug 885. Patch from Karsten.
        - Implement the 0x20 hack to better resist DNS poisoning: set the
          case on outgoing DNS requests randomly, and reject responses that do
          not match the case correctly. This logic can be disabled with the
          ServerDNSRandomizeCase setting, if you are using one of the 0.3%
          of servers that do not reliably preserve case in replies. See
          "Increased DNS Forgery Resistance through 0x20-Bit Encoding"
          for more info.
        - Check DNS replies for more matching fields to better resist DNS
          poisoning.
        - Never use OpenSSL compression: it wastes RAM and CPU trying to
          compress cells, which are basically all encrypted, compressed, or
          both.
    
    
    Changes in version 0.2.0.32 - 2008-11-20
      Tor 0.2.0.32 fixes a major security problem in Debian and Ubuntu
      packages (and maybe other packages) noticed by Theo de Raadt, fixes
      a smaller security flaw that might allow an attacker to access local
      services, further improves hidden service performance, and fixes a
      variety of other issues.
    
      o Security fixes:
        - The "User" and "Group" config options did not clear the
          supplementary group entries for the Tor process. The "User" option
          is now more robust, and we now set the groups to the specified
          user's primary group. The "Group" option is now ignored. For more
          detailed logging on credential switching, set CREDENTIAL_LOG_LEVEL
          in common/compat.c to LOG_NOTICE or higher. Patch by Jacob Appelbaum
          and Steven Murdoch. Bugfix on 0.0.2pre14. Fixes bug 848 and 857.
        - The "ClientDNSRejectInternalAddresses" config option wasn't being
          consistently obeyed: if an exit relay refuses a stream because its
          exit policy doesn't allow it, we would remember what IP address
          the relay said the destination address resolves to, even if it's
          an internal IP address. Bugfix on 0.2.0.7-alpha; patch by rovv.
    
      o Major bugfixes:
        - Fix a DOS opportunity during the voting signature collection process
          at directory authorities. Spotted by rovv. Bugfix on 0.2.0.x.
    
      o Major bugfixes (hidden services):
        - When fetching v0 and v2 rendezvous service descriptors in parallel,
          we were failing the whole hidden service request when the v0
          descriptor fetch fails, even if the v2 fetch is still pending and
          might succeed. Similarly, if the last v2 fetch fails, we were
          failing the whole hidden service request even if a v0 fetch is
          still pending. Fixes bug 814. Bugfix on 0.2.0.10-alpha.
        - When extending a circuit to a hidden service directory to upload a
          rendezvous descriptor using a BEGIN_DIR cell, almost 1/6 of all
          requests failed, because the router descriptor has not been
          downloaded yet. In these cases, do not attempt to upload the
          rendezvous descriptor, but wait until the router descriptor is
          downloaded and retry. Likewise, do not attempt to fetch a rendezvous
          descriptor from a hidden service directory for which the router
          descriptor has not yet been downloaded. Fixes bug 767. Bugfix
          on 0.2.0.10-alpha.
    
      o Minor bugfixes:
        - Fix several infrequent memory leaks spotted by Coverity.
        - When testing for libevent functions, set the LDFLAGS variable
          correctly. Found by Riastradh.
        - Avoid a bug where the FastFirstHopPK 0 option would keep Tor from
          bootstrapping with tunneled directory connections. Bugfix on
          0.1.2.5-alpha. Fixes bug 797. Found by Erwin Lam.
        - When asked to connect to A.B.exit:80, if we don't know the IP for A
          and we know that server B rejects most-but-not all connections to
          port 80, we would previously reject the connection. Now, we assume
          the user knows what they were asking for. Fixes bug 752. Bugfix
          on 0.0.9rc5. Diagnosed by BarkerJr.
        - If we overrun our per-second write limits a little, count this as
          having used up our write allocation for the second, and choke
          outgoing directory writes. Previously, we had only counted this when
          we had met our limits precisely. Fixes bug 824. Patch from by rovv.
          Bugfix on 0.2.0.x (??).
        - Remove the old v2 directory authority 'lefkada' from the default
          list. It has been gone for many months.
        - Stop doing unaligned memory access that generated bus errors on
          sparc64. Bugfix on 0.2.0.10-alpha. Fixes bug 862.
        - Make USR2 log-level switch take effect immediately. Bugfix on
          0.1.2.8-beta.
    
      o Minor bugfixes (controller):
        - Make DNS resolved events into "CLOSED", not "FAILED". Bugfix on
          0.1.2.5-alpha. Fix by Robert Hogan. Resolves bug 807.
    
    
    Changes in version 0.2.0.31 - 2008-09-03
      Tor 0.2.0.31 addresses two potential anonymity issues, starts to fix
      a big bug we're seeing where in rare cases traffic from one Tor stream
      gets mixed into another stream, and fixes a variety of smaller issues.
    
      o Major bugfixes:
        - Make sure that two circuits can never exist on the same connection
          with the same circuit ID, even if one is marked for close. This
          is conceivably a bugfix for bug 779. Bugfix on 0.1.0.4-rc.
        - Relays now reject risky extend cells: if the extend cell includes
          a digest of all zeroes, or asks to extend back to the relay that
          sent the extend cell, tear down the circuit. Ideas suggested
          by rovv.
        - If not enough of our entry guards are available so we add a new
          one, we might use the new one even if it overlapped with the
          current circuit's exit relay (or its family). Anonymity bugfix
          pointed out by rovv.
    
      o Minor bugfixes:
        - Recover 3-7 bytes that were wasted per memory chunk. Fixes bug
          794; bug spotted by rovv. Bugfix on 0.2.0.1-alpha.
        - Correctly detect the presence of the linux/netfilter_ipv4.h header
          when building against recent kernels. Bugfix on 0.1.2.1-alpha.
        - Pick size of default geoip filename string correctly on windows.
          Fixes bug 806. Bugfix on 0.2.0.30.
        - Make the autoconf script accept the obsolete --with-ssl-dir
          option as an alias for the actually-working --with-openssl-dir
          option. Fix the help documentation to recommend --with-openssl-dir.
          Based on a patch by "Dave". Bugfix on 0.2.0.1-alpha.
        - When using the TransPort option on OpenBSD, and using the User
          option to change UID and drop privileges, make sure to open
          /dev/pf before dropping privileges. Fixes bug 782. Patch from
          Christopher Davis. Bugfix on 0.1.2.1-alpha.
        - Try to attach connections immediately upon receiving a RENDEZVOUS2
          or RENDEZVOUS_ESTABLISHED cell. This can save a second or two
          on the client side when connecting to a hidden service. Bugfix
          on 0.0.6pre1. Found and fixed by Christian Wilms; resolves bug 743.
        - When closing an application-side connection because its circuit is
          getting torn down, generate the stream event correctly. Bugfix on
          0.1.2.x. Anonymous patch.
    
    
    Changes in version 0.2.0.30 - 2008-07-15
      This new stable release switches to a more efficient directory
      distribution design, adds features to make connections to the Tor
      network harder to block, allows Tor to act as a DNS proxy, adds separate
      rate limiting for relayed traffic to make it easier for clients to
      become relays, fixes a variety of potential anonymity problems, and
      includes the usual huge pile of other features and bug fixes.
    
      o New v3 directory design:
        - Tor now uses a new way to learn about and distribute information
          about the network: the directory authorities vote on a common
          network status document rather than each publishing their own
          opinion. Now clients and caches download only one networkstatus
          document to bootstrap, rather than downloading one for each
          authority. Clients only download router descriptors listed in
          the consensus. Implements proposal 101; see doc/spec/dir-spec.txt
          for details.
        - Set up moria1, tor26, and dizum as v3 directory authorities
          in addition to being v2 authorities. Also add three new ones:
          ides (run by Mike Perry), gabelmoo (run by Karsten Loesing), and
          dannenberg (run by CCC).
        - Switch to multi-level keys for directory authorities: now their
          long-term identity key can be kept offline, and they periodically
          generate a new signing key. Clients fetch the "key certificates"
          to keep up to date on the right keys. Add a standalone tool
          "tor-gencert" to generate key certificates. Implements proposal 103.
        - Add a new V3AuthUseLegacyKey config option to make it easier for
          v3 authorities to change their identity keys if another bug like
          Debian's OpenSSL RNG flaw appears.
        - Authorities and caches fetch the v2 networkstatus documents
          less often, now that v3 is recommended.
    
      o Make Tor connections stand out less on the wire:
        - Use an improved TLS handshake designed by Steven Murdoch in proposal
          124, as revised in proposal 130. The new handshake is meant to
          be harder for censors to fingerprint, and it adds the ability
          to detect certain kinds of man-in-the-middle traffic analysis
          attacks. The new handshake format includes version negotiation for
          OR connections as described in proposal 105, which will allow us
          to improve Tor's link protocol more safely in the future.
        - Enable encrypted directory connections by default for non-relays,
          so censor tools that block Tor directory connections based on their
          plaintext patterns will no longer work. This means Tor works in
          certain censored countries by default again.
        - Stop including recognizeable strings in the commonname part of
          Tor's x509 certificates.
    
      o Implement bridge relays:
        - Bridge relays (or "bridges" for short) are Tor relays that aren't
          listed in the main Tor directory. Since there is no complete public
          list of them, even an ISP that is filtering connections to all the
          known Tor relays probably won't be able to block all the bridges.
          See doc/design-paper/blocking.pdf and proposal 125 for details.
        - New config option BridgeRelay that specifies you want to be a
          bridge relay rather than a normal relay. When BridgeRelay is set
          to 1, then a) you cache dir info even if your DirPort ins't on,
          and b) the default for PublishServerDescriptor is now "bridge"
          rather than "v2,v3".
        - New config option "UseBridges 1" for clients that want to use bridge
          relays instead of ordinary entry guards. Clients then specify
          bridge relays by adding "Bridge" lines to their config file. Users
          can learn about a bridge relay either manually through word of
          mouth, or by one of our rate-limited mechanisms for giving out
          bridge addresses without letting an attacker easily enumerate them
          all. See https://www.torproject.org/bridges for details.
        - Bridge relays behave like clients with respect to time intervals
          for downloading new v3 consensus documents -- otherwise they
          stand out. Bridge users now wait until the end of the interval,
          so their bridge relay will be sure to have a new consensus document.
    
      o Implement bridge directory authorities:
        - Bridge authorities are like normal directory authorities, except
          they don't serve a list of known bridges. Therefore users that know
          a bridge's fingerprint can fetch a relay descriptor for that bridge,
          including fetching updates e.g. if the bridge changes IP address,
          yet an attacker can't just fetch a list of all the bridges.
        - Set up Tonga as the default bridge directory authority.
        - Bridge authorities refuse to serve bridge descriptors or other
          bridge information over unencrypted connections (that is, when
          responding to direct DirPort requests rather than begin_dir cells.)
        - Bridge directory authorities do reachability testing on the
          bridges they know. They provide router status summaries to the
          controller via "getinfo ns/purpose/bridge", and also dump summaries
          to a file periodically, so we can keep internal stats about which
          bridges are functioning.
        - If bridge users set the UpdateBridgesFromAuthority config option,
          but the digest they ask for is a 404 on the bridge authority,
          they fall back to contacting the bridge directly.
        - Bridges always use begin_dir to publish their server descriptor to
          the bridge authority using an anonymous encrypted tunnel.
        - Early work on a "bridge community" design: if bridge authorities set
          the BridgePassword config option, they will serve a snapshot of
          known bridge routerstatuses from their DirPort to anybody who
          knows that password. Unset by default.
        - Tor now includes an IP-to-country GeoIP file, so bridge relays can
          report sanitized aggregated summaries in their extra-info documents
          privately to the bridge authority, listing which countries are
          able to reach them. We hope this mechanism will let us learn when
          certain countries start trying to block bridges.
        - Bridge authorities write bridge descriptors to disk, so they can
          reload them after a reboot. They can also export the descriptors
          to other programs, so we can distribute them to blocked users via
          the BridgeDB interface, e.g. via https://bridges.torproject.org/
          and bridges@torproject.org.
    
      o Tor can be a DNS proxy:
        - The new client-side DNS proxy feature replaces the need for
          dns-proxy-tor: Just set "DNSPort 9999", and Tor will now listen
          for DNS requests on port 9999, use the Tor network to resolve them
          anonymously, and send the reply back like a regular DNS server.
          The code still only implements a subset of DNS.
        - Add a new AutomapHostsOnResolve option: when it is enabled, any
          resolve request for hosts matching a given pattern causes Tor to
          generate an internal virtual address mapping for that host. This
          allows DNSPort to work sensibly with hidden service users. By
          default, .exit and .onion addresses are remapped; the list of
          patterns can be reconfigured with AutomapHostsSuffixes.
        - Add an "-F" option to tor-resolve to force a resolve for a .onion
          address. Thanks to the AutomapHostsOnResolve option, this is no
          longer a completely silly thing to do.
    
      o Major features (relay usability):
        - New config options RelayBandwidthRate and RelayBandwidthBurst:
          a separate set of token buckets for relayed traffic. Right now
          relayed traffic is defined as answers to directory requests, and
          OR connections that don't have any local circuits on them. See
          proposal 111 for details.
        - Create listener connections before we setuid to the configured
          User and Group. Now non-Windows users can choose port values
          under 1024, start Tor as root, and have Tor bind those ports
          before it changes to another UID. (Windows users could already
          pick these ports.)
        - Added a new ConstrainedSockets config option to set SO_SNDBUF and
          SO_RCVBUF on TCP sockets. Hopefully useful for Tor servers running
          on "vserver" accounts. Patch from coderman.
    
      o Major features (directory authorities):
        - Directory authorities track weighted fractional uptime and weighted
          mean-time-between failures for relays. WFU is suitable for deciding
          whether a node is "usually up", while MTBF is suitable for deciding
          whether a node is "likely to stay up." We need both, because
          "usually up" is a good requirement for guards, while "likely to
          stay up" is a good requirement for long-lived connections.
        - Directory authorities use a new formula for selecting which relays
          to advertise as Guards: they must be in the top 7/8 in terms of
          how long we have known about them, and above the median of those
          nodes in terms of weighted fractional uptime.
        - Directory authorities use a new formula for selecting which relays
          to advertise as Stable: when we have 4 or more days of data, use
          median measured MTBF rather than median declared uptime. Implements
          proposal 108.
        - Directory authorities accept and serve "extra info" documents for
          routers. Routers now publish their bandwidth-history lines in the
          extra-info docs rather than the main descriptor. This step saves
          60% (!) on compressed router descriptor downloads. Servers upload
          extra-info docs to any authority that accepts them; directory
          authorities now allow multiple router descriptors and/or extra
          info documents to be uploaded in a single go. Authorities, and
          caches that have been configured to download extra-info documents,
          download them as needed. Implements proposal 104.
        - Authorities now list relays who have the same nickname as
          a different named relay, but list them with a new flag:
          "Unnamed". Now we can make use of relays that happen to pick the
          same nickname as a server that registered two years ago and then
          disappeared. Implements proposal 122.
        - Store routers in a file called cached-descriptors instead of in
          cached-routers. Initialize cached-descriptors from cached-routers
          if the old format is around. The new format allows us to store
          annotations along with descriptors, to record the time we received
          each descriptor, its source, and its purpose: currently one of
          general, controller, or bridge.
    
      o Major features (other):
        - New config options WarnPlaintextPorts and RejectPlaintextPorts so
          Tor can warn and/or refuse connections to ports commonly used with
          vulnerable-plaintext protocols. Currently we warn on ports 23,
          109, 110, and 143, but we don't reject any. Based on proposal 129
          by Kevin Bauer and Damon McCoy.
        - Integrate Karsten Loesing's Google Summer of Code project to publish
          hidden service descriptors on a set of redundant relays that are a
          function of the hidden service address. Now we don't have to rely
          on three central hidden service authorities for publishing and
          fetching every hidden service descriptor. Implements proposal 114.
        - Allow tunnelled directory connections to ask for an encrypted
          "begin_dir" connection or an anonymized "uses a full Tor circuit"
          connection independently. Now we can make anonymized begin_dir
          connections for (e.g.) more secure hidden service posting and
          fetching.
    
      o Major bugfixes (crashes and assert failures):
        - Stop imposing an arbitrary maximum on the number of file descriptors
          used for busy servers. Bug reported by Olaf Selke; patch from
          Sebastian Hahn.
        - Avoid possible failures when generating a directory with routers
          with over-long versions strings, or too many flags set.
        - Fix a rare assert error when we're closing one of our threads:
          use a mutex to protect the list of logs, so we never write to the
          list as it's being freed. Fixes the very rare bug 575, which is
          kind of the revenge of bug 222.
        - Avoid segfault in the case where a badly behaved v2 versioning
          directory sends a signed networkstatus with missing client-versions.
        - When we hit an EOF on a log (probably because we're shutting down),
          don't try to remove the log from the list: just mark it as
          unusable. (Bulletproofs against bug 222.)
    
      o Major bugfixes (code security fixes):
        - Detect size overflow in zlib code. Reported by Justin Ferguson and
          Dan Kaminsky.
        - Rewrite directory tokenization code to never run off the end of
          a string. Fixes bug 455. Patch from croup.
        - Be more paranoid about overwriting sensitive memory on free(),
          as a defensive programming tactic to ensure forward secrecy.
    
      o Major bugfixes (anonymity fixes):
        - Reject requests for reverse-dns lookup of names that are in
          a private address space. Patch from lodger.
        - Never report that we've used more bandwidth than we're willing to
          relay: it leaks how much non-relay traffic we're using. Resolves
          bug 516.
        - As a client, do not believe any server that tells us that an
          address maps to an internal address space.
        - Warn about unsafe ControlPort configurations.
        - Directory authorities now call routers Fast if their bandwidth is
          at least 100KB/s, and consider their bandwidth adequate to be a
          Guard if it is at least 250KB/s, no matter the medians. This fix
          complements proposal 107.
        - Directory authorities now never mark more than 2 servers per IP as
          Valid and Running (or 5 on addresses shared by authorities).
          Implements proposal 109, by Kevin Bauer and Damon McCoy.
        - If we're a relay, avoid picking ourselves as an introduction point,
          a rendezvous point, or as the final hop for internal circuits. Bug
          reported by taranis and lodger.
        - Exit relays that are used as a client can now reach themselves
          using the .exit notation, rather than just launching an infinite
          pile of circuits. Fixes bug 641. Reported by Sebastian Hahn.
        - Fix a bug where, when we were choosing the 'end stream reason' to
          put in our relay end cell that we send to the exit relay, Tor
          clients on Windows were sometimes sending the wrong 'reason'. The
          anonymity problem is that exit relays may be able to guess whether
          the client is running Windows, thus helping partition the anonymity
          set. Down the road we should stop sending reasons to exit relays,
          or otherwise prevent future versions of this bug.
        - Only update guard status (usable / not usable) once we have
          enough directory information. This was causing us to discard all our
          guards on startup if we hadn't been running for a few weeks. Fixes
          bug 448.
        - When our directory information has been expired for a while, stop
          being willing to build circuits using it. Fixes bug 401.
    
      o Major bugfixes (peace of mind for relay operators)
        - Non-exit relays no longer answer "resolve" relay cells, so they
          can't be induced to do arbitrary DNS requests. (Tor clients already
          avoid using non-exit relays for resolve cells, but now servers
          enforce this too.) Fixes bug 619. Patch from lodger.
        - When we setconf ClientOnly to 1, close any current OR and Dir
          listeners. Reported by mwenge.
    
      o Major bugfixes (other):
        - If we only ever used Tor for hidden service lookups or posts, we
          would stop building circuits and start refusing connections after
          24 hours, since we falsely believed that Tor was dormant. Reported
          by nwf.
        - Add a new __HashedControlSessionPassword option for controllers
          to use for one-off session password hashes that shouldn't get
          saved to disk by SAVECONF --- Vidalia users were accumulating a
          pile of HashedControlPassword lines in their torrc files, one for
          each time they had restarted Tor and then clicked Save. Make Tor
          automatically convert "HashedControlPassword" to this new option but
          only when it's given on the command line. Partial fix for bug 586.
        - Patch from "Andrew S. Lists" to catch when we contact a directory
          mirror at IP address X and he says we look like we're coming from
          IP address X. Otherwise this would screw up our address detection.
        - Reject uploaded descriptors and extrainfo documents if they're
          huge. Otherwise we'll cache them all over the network and it'll
          clog everything up. Suggested by Aljosha Judmayer.
        - When a hidden service was trying to establish an introduction point,
          and Tor *did* manage to reuse one of the preemptively built
          circuits, it didn't correctly remember which one it used,
          so it asked for another one soon after, until there were no
          more preemptive circuits, at which point it launched one from
          scratch. Bugfix on 0.0.9.x.
    
      o Rate limiting and load balancing improvements:
        - When we add data to a write buffer in response to the data on that
          write buffer getting low because of a flush, do not consider the
          newly added data as a candidate for immediate flushing, but rather
          make it wait until the next round of writing. Otherwise, we flush
          and refill recursively, and a single greedy TLS connection can
          eat all of our bandwidth.
        - When counting the number of bytes written on a TLS connection,
          look at the BIO actually used for writing to the network, not
          at the BIO used (sometimes) to buffer data for the network.
          Looking at different BIOs could result in write counts on the
          order of ULONG_MAX. Fixes bug 614.
        - If we change our MaxAdvertisedBandwidth and then reload torrc,
          Tor won't realize it should publish a new relay descriptor. Fixes
          bug 688, reported by mfr.
        - Avoid using too little bandwidth when our clock skips a few seconds.
        - Choose which bridge to use proportional to its advertised bandwidth,
          rather than uniformly at random. This should speed up Tor for
          bridge users. Also do this for people who set StrictEntryNodes.
    
      o Bootstrapping faster and building circuits more intelligently:
        - Fix bug 660 that was preventing us from knowing that we should
          preemptively build circuits to handle expected directory requests.
        - When we're checking if we have enough dir info for each relay
          to begin establishing circuits, make sure that we actually have
          the descriptor listed in the consensus, not just any descriptor.
        - Correctly notify one-hop connections when a circuit build has
          failed. Possible fix for bug 669. Found by lodger.
        - Clients now hold circuitless TLS connections open for 1.5 times
          MaxCircuitDirtiness (15 minutes), since it is likely that they'll
          rebuild a new circuit over them within that timeframe. Previously,
          they held them open only for KeepalivePeriod (5 minutes).
    
      o Performance improvements (memory):
        - Add OpenBSD malloc code from "phk" as an optional malloc
          replacement on Linux: some glibc libraries do very poorly with
          Tor's memory allocation patterns. Pass --enable-openbsd-malloc to
          ./configure to get the replacement malloc code.
        - Switch our old ring buffer implementation for one more like that
          used by free Unix kernels. The wasted space in a buffer with 1mb
          of data will now be more like 8k than 1mb. The new implementation
          also avoids realloc();realloc(); patterns that can contribute to
          memory fragmentation.
        - Change the way that Tor buffers data that it is waiting to write.
          Instead of queueing data cells in an enormous ring buffer for each
          client->OR or OR->OR connection, we now queue cells on a separate
          queue for each circuit. This lets us use less slack memory, and
          will eventually let us be smarter about prioritizing different kinds
          of traffic.
        - Reference-count and share copies of address policy entries; only 5%
          of them were actually distinct.
        - Tune parameters for cell pool allocation to minimize amount of
          RAM overhead used.
        - Keep unused 4k and 16k buffers on free lists, rather than wasting 8k
          for every single inactive connection_t. Free items from the
          4k/16k-buffer free lists when they haven't been used for a while.
        - Make memory debugging information describe more about history
          of cell allocation, so we can help reduce our memory use.
        - Be even more aggressive about releasing RAM from small
          empty buffers. Thanks to our free-list code, this shouldn't be too
          performance-intensive.
        - Log malloc statistics from mallinfo() on platforms where it exists.
        - Use memory pools to allocate cells with better speed and memory
          efficiency, especially on platforms where malloc() is inefficient.
        - Add a --with-tcmalloc option to the configure script to link
          against tcmalloc (if present). Does not yet search for non-system
          include paths.
    
      o Performance improvements (socket management):
        - Count the number of open sockets separately from the number of
          active connection_t objects. This will let us avoid underusing
          our allocated connection limit.
        - We no longer use socket pairs to link an edge connection to an
          anonymous directory connection or a DirPort test connection.
          Instead, we track the link internally and transfer the data
          in-process. This saves two sockets per "linked" connection (at the
          client and at the server), and avoids the nasty Windows socketpair()
          workaround.
        - We were leaking a file descriptor if Tor started with a zero-length
          cached-descriptors file. Patch by "freddy77".
    
      o Performance improvements (CPU use):
        - Never walk through the list of logs if we know that no log target
          is interested in a given message.
        - Call routerlist_remove_old_routers() much less often. This should
          speed startup, especially on directory caches.
        - Base64 decoding was actually showing up on our profile when parsing
          the initial descriptor file; switch to an in-process all-at-once
          implementation that's about 3.5x times faster than calling out to
          OpenSSL.
        - Use a slightly simpler string hashing algorithm (copying Python's
          instead of Java's) and optimize our digest hashing algorithm to take
          advantage of 64-bit platforms and to remove some possibly-costly
          voodoo.
        - When implementing AES counter mode, update only the portions of the
          counter buffer that need to change, and don't keep separate
          network-order and host-order counters on big-endian hosts (where
          they are the same).
        - Add an in-place version of aes_crypt() so that we can avoid doing a
          needless memcpy() call on each cell payload.
        - Use Critical Sections rather than Mutexes for synchronizing threads
          on win32; Mutexes are heavier-weight, and designed for synchronizing
          between processes.
    
      o Performance improvements (bandwidth use):
        - Don't try to launch new descriptor downloads quite so often when we
          already have enough directory information to build circuits.
        - Version 1 directories are no longer generated in full. Instead,
          authorities generate and serve "stub" v1 directories that list
          no servers. This will stop Tor versions 0.1.0.x and earlier from
          working, but (for security reasons) nobody should be running those
          versions anyway.
        - Avoid going directly to the directory authorities even if you're a
          relay, if you haven't found yourself reachable yet or if you've
          decided not to advertise your dirport yet. Addresses bug 556.
        - If we've gone 12 hours since our last bandwidth check, and we
          estimate we have less than 50KB bandwidth capacity but we could
          handle more, do another bandwidth test.
        - Support "If-Modified-Since" when answering HTTP requests for
          directories, running-routers documents, and v2 and v3 networkstatus
          documents. (There's no need to support it for router descriptors,
          since those are downloaded by descriptor digest.)
        - Stop fetching directory info so aggressively if your DirPort is
          on but your ORPort is off; stop fetching v2 dir info entirely.
          You can override these choices with the new FetchDirInfoEarly
          config option.
    
      o Changed config option behavior (features):
        - Configuration files now accept C-style strings as values. This
          helps encode characters not allowed in the current configuration
          file format, such as newline or #. Addresses bug 557.
        - Add hidden services and DNSPorts to the list of things that make
          Tor accept that it has running ports. Change starting Tor with no
          ports from a fatal error to a warning; we might change it back if
          this turns out to confuse anybody. Fixes bug 579.
        - Make PublishServerDescriptor default to 1, so the default doesn't
          have to change as we invent new directory protocol versions.
        - Allow people to say PreferTunnelledDirConns rather than
          PreferTunneledDirConns, for those alternate-spellers out there.
        - Raise the default BandwidthRate/BandwidthBurst to 5MB/10MB, to
          accommodate the growing number of servers that use the default
          and are reaching it.
        - Make it possible to enable HashedControlPassword and
          CookieAuthentication at the same time.
        - When a TrackHostExits-chosen exit fails too many times in a row,
          stop using it. Fixes bug 437.
    
      o Changed config option behavior (bugfixes):
        - Do not read the configuration file when we've only been told to
          generate a password hash. Fixes bug 643. Bugfix on 0.0.9pre5. Fix
          based on patch from Sebastian Hahn.
        - Actually validate the options passed to AuthDirReject,
          AuthDirInvalid, AuthDirBadDir, and AuthDirBadExit.
        - Make "ClientOnly 1" config option disable directory ports too.
        - Don't stop fetching descriptors when FetchUselessDescriptors is
          set, even if we stop asking for circuits. Bug reported by tup
          and ioerror.
        - Servers used to decline to publish their DirPort if their
          BandwidthRate or MaxAdvertisedBandwidth were below a threshold. Now
          they look only at BandwidthRate and RelayBandwidthRate.
        - Treat "2gb" when given in torrc for a bandwidth as meaning 2gb,
          minus 1 byte: the actual maximum declared bandwidth.
        - Make "TrackHostExits ." actually work. Bugfix on 0.1.0.x.
        - Make the NodeFamilies config option work. (Reported by
          lodger -- it has never actually worked, even though we added it
          in Oct 2004.)
        - If Tor is invoked from something that isn't a shell (e.g. Vidalia),
          now we expand "-f ~/.tor/torrc" correctly. Suggested by Matt Edman.
    
      o New config options:
        - New configuration options AuthDirMaxServersPerAddr and
          AuthDirMaxServersperAuthAddr to override default maximum number
          of servers allowed on a single IP address. This is important for
          running a test network on a single host.
        - Three new config options (AlternateDirAuthority,
          AlternateBridgeAuthority, and AlternateHSAuthority) that let the
          user selectively replace the default directory authorities by type,
          rather than the all-or-nothing replacement that DirServer offers.
        - New config options AuthDirBadDir and AuthDirListBadDirs for
          authorities to mark certain relays as "bad directories" in the
          networkstatus documents. Also supports the "!baddir" directive in
          the approved-routers file.
        - New config option V2AuthoritativeDirectory that all v2 directory
          authorities must set. This lets v3 authorities choose not to serve
          v2 directory information.
    
      o Minor features (other):
        - When we're not serving v2 directory information, there is no reason
          to actually keep any around. Remove the obsolete files and directory
          on startup if they are very old and we aren't going to serve them.
        - When we negotiate a v2 link-layer connection (not yet implemented),
          accept RELAY_EARLY cells and turn them into RELAY cells if we've
          negotiated a v1 connection for their next step. Initial steps for
          proposal 110.
        - When we have no consensus, check FallbackNetworkstatusFile (defaults
          to $PREFIX/share/tor/fallback-consensus) for a consensus. This way
          we can start out knowing some directory caches. We don't ship with
          a fallback consensus by default though, because it was making
          bootstrapping take too long while we tried many down relays.
        - Authorities send back an X-Descriptor-Not-New header in response to
          an accepted-but-discarded descriptor upload. Partially implements
          fix for bug 535.
        - If we find a cached-routers file that's been sitting around for more
          than 28 days unmodified, then most likely it's a leftover from
          when we upgraded to 0.2.0.8-alpha. Remove it. It has no good
          routers anyway.
        - When we (as a cache) download a descriptor because it was listed
          in a consensus, remember when the consensus was supposed to expire,
          and don't expire the descriptor until then.
        - Optionally (if built with -DEXPORTMALLINFO) export the output
          of mallinfo via http, as tor/mallinfo.txt. Only accessible
          from localhost.
        - Tag every guard node in our state file with the version that
          we believe added it, or with our own version if we add it. This way,
          if a user temporarily runs an old version of Tor and then switches
          back to a new one, she doesn't automatically lose her guards.
        - When somebody requests a list of statuses or servers, and we have
          none of those, return a 404 rather than an empty 200.
        - Merge in some (as-yet-unused) IPv6 address manipulation code. (Patch
          from croup.)
        - Add an HSAuthorityRecordStats option that hidden service authorities
          can use to track statistics of overall hidden service usage without
          logging information that would be as useful to an attacker.
        - Allow multiple HiddenServicePort directives with the same virtual
          port; when they occur, the user is sent round-robin to one
          of the target ports chosen at random.  Partially fixes bug 393 by
          adding limited ad-hoc round-robining.
        - Revamp file-writing logic so we don't need to have the entire
          contents of a file in memory at once before we write to disk. Tor,
          meet stdio.
    
      o Minor bugfixes (other):
        - Alter the code that tries to recover from unhandled write
          errors, to not try to flush onto a socket that's given us
          unhandled errors.
        - Directory mirrors no longer include a guess at the client's IP
          address if the connection appears to be coming from the same /24
          network; it was producing too many wrong guesses.
        - If we're trying to flush the last bytes on a connection (for
          example, when answering a directory request), reset the
          time-to-give-up timeout every time we manage to write something
          on the socket.
        - Reject router descriptors with out-of-range bandwidthcapacity or
          bandwidthburst values.
        - If we can't expand our list of entry guards (e.g. because we're
          using bridges or we have StrictEntryNodes set), don't mark relays
          down when they fail a directory request. Otherwise we're too quick
          to mark all our entry points down.
        - Authorities no longer send back "400 you're unreachable please fix
          it" errors to Tor servers that aren't online all the time. We're
          supposed to tolerate these servers now.
        - Let directory authorities startup even when they can't generate
          a descriptor immediately, e.g. because they don't know their
          address.
        - Correctly enforce that elements of directory objects do not appear
          more often than they are allowed to appear.
        - Stop allowing hibernating servers to be "stable" or "fast".
        - On Windows, we were preventing other processes from reading
          cached-routers while Tor was running. (Reported by janbar)
        - Check return values from pthread_mutex functions.
        - When opening /dev/null in finish_daemonize(), do not pass the
          O_CREAT flag. Fortify was complaining, and correctly so. Fixes
          bug 742; fix from Michael Scherer. Bugfix on 0.0.2pre19.
    
      o Controller features:
        - The GETCONF command now escapes and quotes configuration values
          that don't otherwise fit into the torrc file.
        - The SETCONF command now handles quoted values correctly.
        - Add "GETINFO/desc-annotations/id/<OR digest>" so controllers can
          ask about source, timestamp of arrival, purpose, etc. We need
          something like this to help Vidalia not do GeoIP lookups on bridge
          addresses.
        - Allow multiple HashedControlPassword config lines, to support
          multiple controller passwords.
        - Accept LF instead of CRLF on controller, since some software has a
          hard time generating real Internet newlines.
        - Add GETINFO values for the server status events
          "REACHABILITY_SUCCEEDED" and "GOOD_SERVER_DESCRIPTOR". Patch from
          Robert Hogan.
        - There is now an ugly, temporary "desc/all-recent-extrainfo-hack"
          GETINFO for Torstat to use until it can switch to using extrainfos.
        - New config option CookieAuthFile to choose a new location for the
          cookie authentication file, and config option
          CookieAuthFileGroupReadable to make it group-readable.
        - Add a SOURCE_ADDR field to STREAM NEW events so that controllers can
          match requests to applications. Patch from Robert Hogan.
        - Add a RESOLVE command to launch hostname lookups. Original patch
          from Robert Hogan.
        - Add GETINFO status/enough-dir-info to let controllers tell whether
          Tor has downloaded sufficient directory information. Patch from Tup.
        - You can now use the ControlSocket option to tell Tor to listen for
          controller connections on Unix domain sockets on systems that
          support them. Patch from Peter Palfrader.
        - New "GETINFO address-mappings/*" command to get address mappings
          with expiry information. "addr-mappings/*" is now deprecated.
          Patch from Tup.
        - Add a new config option __DisablePredictedCircuits designed for
          use by the controller, when we don't want Tor to build any circuits
          preemptively.
        - Let the controller specify HOP=%d as an argument to ATTACHSTREAM,
          so we can exit from the middle of the circuit.
        - Implement "getinfo status/circuit-established".
        - Implement "getinfo status/version/..." so a controller can tell
          whether the current version is recommended, and whether any versions
          are good, and how many authorities agree. Patch from "shibz".
        - Controllers should now specify cache=no or cache=yes when using
          the +POSTDESCRIPTOR command.
        - Add a "PURPOSE=" argument to "STREAM NEW" events, as suggested by
          Robert Hogan. Fixes the first part of bug 681.
        - When reporting clock skew, and we know that the clock is _at least
          as skewed_ as some value, but we don't know the actual value,
          report the value as a "minimum skew."
    
      o Controller bugfixes:
        - Generate "STATUS_SERVER" events rather than misspelled
          "STATUS_SEVER" events. Caught by mwenge.
        - Reject controller commands over 1MB in length, so rogue
          processes can't run us out of memory.
        - Change the behavior of "getinfo status/good-server-descriptor"
          so it doesn't return failure when any authority disappears.
        - Send NAMESERVER_STATUS messages for a single failed nameserver
          correctly.
        - When the DANGEROUS_VERSION controller status event told us we're
          running an obsolete version, it used the string "OLD" to describe
          it. Yet the "getinfo" interface used the string "OBSOLETE". Now use
          "OBSOLETE" in both cases.
        - Respond to INT and TERM SIGNAL commands before we execute the
          signal, in case the signal shuts us down. We had a patch in
          0.1.2.1-alpha that tried to do this by queueing the response on
          the connection's buffer before shutting down, but that really
          isn't the same thing at all. Bug located by Matt Edman.
        - Provide DNS expiry times in GMT, not in local time. For backward
          compatibility, ADDRMAP events only provide GMT expiry in an extended
          field. "GETINFO address-mappings" always does the right thing.
        - Use CRLF line endings properly in NS events.
        - Make 'getinfo fingerprint' return a 551 error if we're not a
          server, so we match what the control spec claims we do. Reported
          by daejees.
        - Fix a typo in an error message when extendcircuit fails that
          caused us to not follow the \r\n-based delimiter protocol. Reported
          by daejees.
        - When tunneling an encrypted directory connection, and its first
          circuit fails, do not leave it unattached and ask the controller
          to deal. Fixes the second part of bug 681.
        - Treat some 403 responses from directory servers as INFO rather than
          WARN-severity events.
    
      o Portability / building / compiling:
        - When building with --enable-gcc-warnings, check for whether Apple's
          warning "-Wshorten-64-to-32" is available.
        - Support compilation to target iPhone; patch from cjacker huang.
          To build for iPhone, pass the --enable-iphone option to configure.
        - Port Tor to build and run correctly on Windows CE systems, using
          the wcecompat library. Contributed by Valerio Lupi.
        - Detect non-ASCII platforms (if any still exist) and refuse to
          build there: some of our code assumes that 'A' is 65 and so on.
        - Clear up some MIPSPro compiler warnings.
        - Make autoconf search for libevent, openssl, and zlib consistently.
        - Update deprecated macros in configure.in.
        - When warning about missing headers, tell the user to let us
          know if the compile succeeds anyway, so we can downgrade the
          warning.
        - Include the current subversion revision as part of the version
          string: either fetch it directly if we're in an SVN checkout, do
          some magic to guess it if we're in an SVK checkout, or use
          the last-detected version if we're building from a .tar.gz.
          Use this version consistently in log messages.
        - Correctly report platform name on Windows 95 OSR2 and Windows 98 SE.
        - Read resolv.conf files correctly on platforms where read() returns
          partial results on small file reads.
        - Build without verbose warnings even on gcc 4.2 and 4.3.
        - On Windows, correctly detect errors when listing the contents of
          a directory. Fix from lodger.
        - Run 'make test' as part of 'make dist', so we stop releasing so
          many development snapshots that fail their unit tests.
        - Add support to detect Libevent versions in the 1.4.x series
          on mingw.
        - Add command-line arguments to unit-test executable so that we can
          invoke any chosen test from the command line rather than having
          to run the whole test suite at once; and so that we can turn on
          logging for the unit tests.
        - Do not automatically run configure from autogen.sh. This
          non-standard behavior tended to annoy people who have built other
          programs.
        - Fix a macro/CPP interaction that was confusing some compilers:
          some GCCs don't like #if/#endif pairs inside macro arguments.
          Fixes bug 707.
        - Fix macro collision between OpenSSL 0.9.8h and Windows headers.
          Fixes bug 704; fix from Steven Murdoch.
        - Correctly detect transparent proxy support on Linux hosts that
          require in.h to be included before netfilter_ipv4.h.  Patch
          from coderman.
    
      o Logging improvements:
        - When we haven't had any application requests lately, don't bother
          logging that we have expired a bunch of descriptors.
        - When attempting to open a logfile fails, tell us why.
        - Only log guard node status when guard node status has changed.
        - Downgrade the 3 most common "INFO" messages to "DEBUG". This will
          make "INFO" 75% less verbose.
        - When SafeLogging is disabled, log addresses along with all TLS
          errors.
        - Report TLS "zero return" case as a "clean close" and "IO error"
          as a "close". Stop calling closes "unexpected closes": existing
          Tors don't use SSL_close(), so having a connection close without
          the TLS shutdown handshake is hardly unexpected.
        - When we receive a consensus from the future, warn about skew.
        - Make "not enough dir info yet" warnings describe *why* Tor feels
          it doesn't have enough directory info yet.
        - On the USR1 signal, when dmalloc is in use, log the top 10 memory
          consumers. (We already do this on HUP.)
        - Give more descriptive well-formedness errors for out-of-range
          hidden service descriptor/protocol versions.
        - Stop recommending that every server operator send mail to tor-ops.
          Resolves bug 597. Bugfix on 0.1.2.x.
        - Improve skew reporting: try to give the user a better log message
          about how skewed they are, and how much this matters.
        - New --quiet command-line option to suppress the default console log.
          Good in combination with --hash-password.
        - Don't complain that "your server has not managed to confirm that its
          ports are reachable" if we haven't been able to build any circuits
          yet.
        - Detect the reason for failing to mmap a descriptor file we just
          wrote, and give a more useful log message.  Fixes bug 533.
        - Always prepend "Bug: " to any log message about a bug.
        - When dumping memory usage, list bytes used in buffer memory
          free-lists.
        - When running with dmalloc, dump more stats on hup and on exit.
        - Put a platform string (e.g. "Linux i686") in the startup log
          message, so when people paste just their logs, we know if it's
          OpenBSD or Windows or what.
        - When logging memory usage, break down memory used in buffers by
          buffer type.
        - When we are reporting the DirServer line we just parsed, we were
          logging the second stanza of the key fingerprint, not the first.
        - Even though Windows is equally happy with / and \ as path separators,
          try to use \ consistently on Windows and / consistently on Unix: it
          makes the log messages nicer.
         - On OSX, stop warning the user that kqueue support in libevent is
          "experimental", since it seems to have worked fine for ages.
    
      o Contributed scripts and tools:
        - Update linux-tor-prio.sh script to allow QoS based on the uid of
          the Tor process. Patch from Marco Bonetti with tweaks from Mike
          Perry.
        - Include the "tor-ctrl.sh" bash script by Stefan Behte to provide
          Unix users an easy way to script their Tor process (e.g. by
          adjusting bandwidth based on the time of the day).
        - In the exitlist script, only consider the most recently published
          server descriptor for each server. Also, when the user requests
          a list of servers that _reject_ connections to a given address,
          explicitly exclude the IPs that also have servers that accept
          connections to that address. Resolves bug 405.
        - Include a new contrib/tor-exit-notice.html file that exit relay
          operators can put on their website to help reduce abuse queries.
    
      o Newly deprecated features:
        - The status/version/num-versioning and status/version/num-concurring
          GETINFO controller options are no longer useful in the v3 directory
          protocol: treat them as deprecated, and warn when they're used.
        - The RedirectExits config option is now deprecated.
    
      o Removed features:
        - Drop the old code to choke directory connections when the
          corresponding OR connections got full: thanks to the cell queue
          feature, OR conns don't get full any more.
        - Remove the old "dns worker" server DNS code: it hasn't been default
          since 0.1.2.2-alpha, and all the servers are using the new
          eventdns code.
        - Remove the code to generate the oldest (v1) directory format.
        - Remove support for the old bw_accounting file: we've been storing
          bandwidth accounting information in the state file since
          0.1.2.5-alpha. This may result in bandwidth accounting errors
          if you try to upgrade from 0.1.1.x or earlier, or if you try to
          downgrade to 0.1.1.x or earlier.
        - Drop support for OpenSSL version 0.9.6. Just about nobody was using
          it, it had no AES, and it hasn't seen any security patches since
          2004.
        - Stop overloading the circuit_t.onionskin field for both "onionskin
          from a CREATE cell that we are waiting for a cpuworker to be
          assigned" and "onionskin from an EXTEND cell that we are going to
          send to an OR as soon as we are connected". Might help with bug 600.
        - Remove the tor_strpartition() function: its logic was confused,
          and it was only used for one thing that could be implemented far
          more easily.
        - Remove the contrib scripts ExerciseServer.py, PathDemo.py,
          and TorControl.py, as they use the old v0 controller protocol,
          and are obsoleted by TorFlow anyway.
        - Drop support for v1 rendezvous descriptors, since we never used
          them anyway, and the code has probably rotted by now. Based on
          patch from Karsten Loesing.
        - Stop allowing address masks that do not correspond to bit prefixes.
          We have warned about these for a really long time; now it's time
          to reject them. (Patch from croup.)
        - Remove an optimization in the AES counter-mode code that assumed
          that the counter never exceeded 2^68. When the counter can be set
          arbitrarily as an IV (as it is by Karsten's new hidden services
          code), this assumption no longer holds.
        - Disable the SETROUTERPURPOSE controller command: it is now
          obsolete.
    
    
    Changes in version 0.1.2.19 - 2008-01-17
      Tor 0.1.2.19 fixes a huge memory leak on exit relays, makes the default
      exit policy a little bit more conservative so it's safer to run an
      exit relay on a home system, and fixes a variety of smaller issues.
    
      o Security fixes:
        - Exit policies now reject connections that are addressed to a
          relay's public (external) IP address too, unless
          ExitPolicyRejectPrivate is turned off. We do this because too
          many relays are running nearby to services that trust them based
          on network address.
    
      o Major bugfixes:
        - When the clock jumps forward a lot, do not allow the bandwidth
          buckets to become negative. Fixes bug 544.
        - Fix a memory leak on exit relays; we were leaking a cached_resolve_t
          on every successful resolve. Reported by Mike Perry.
        - Purge old entries from the "rephist" database and the hidden
          service descriptor database even when DirPort is zero.
        - Stop thinking that 0.1.2.x directory servers can handle "begin_dir"
          requests. Should ease bugs 406 and 419 where 0.1.2.x relays are
          crashing or mis-answering these requests.
        - When we decide to send a 503 response to a request for servers, do
          not then also send the server descriptors: this defeats the whole
          purpose. Fixes bug 539.
    
      o Minor bugfixes:
        - Changing the ExitPolicyRejectPrivate setting should cause us to
          rebuild our server descriptor.
        - Fix handling of hex nicknames when answering controller requests for
          networkstatus by name, or when deciding whether to warn about
          unknown routers in a config option. (Patch from mwenge.)
        - Fix a couple of hard-to-trigger autoconf problems that could result
          in really weird results on platforms whose sys/types.h files define
          nonstandard integer types.
        - Don't try to create the datadir when running --verify-config or
          --hash-password. Resolves bug 540.
        - If we were having problems getting a particular descriptor from the
          directory caches, and then we learned about a new descriptor for
          that router, we weren't resetting our failure count. Reported
          by lodger.
        - Although we fixed bug 539 (where servers would send HTTP status 503
          responses _and_ send a body too), there are still servers out there
          that haven't upgraded. Therefore, make clients parse such bodies
          when they receive them.
        - Run correctly on systems where rlim_t is larger than unsigned long.
          This includes some 64-bit systems.
        - Run correctly on platforms (like some versions of OS X 10.5) where
          the real limit for number of open files is OPEN_FILES, not rlim_max
          from getrlimit(RLIMIT_NOFILES).
        - Avoid a spurious free on base64 failure.
        - Avoid segfaults on certain complex invocations of
          router_get_by_hexdigest().
        - Fix rare bug on REDIRECTSTREAM control command when called with no
          port set: it could erroneously report an error when none had
          happened.
    
    
    Changes in version 0.1.2.18 - 2007-10-28
      Tor 0.1.2.18 fixes many problems including crash bugs, problems with
      hidden service introduction that were causing huge delays, and a big
      bug that was causing some servers to disappear from the network status
      lists for a few hours each day.
    
      o Major bugfixes (crashes):
        - If a connection is shut down abruptly because of something that
          happened inside connection_flushed_some(), do not call
          connection_finished_flushing(). Should fix bug 451:
          "connection_stop_writing: Assertion conn->write_event failed"
          Bugfix on 0.1.2.7-alpha.
        - Fix possible segfaults in functions called from
          rend_process_relay_cell().
    
      o Major bugfixes (hidden services):
        - Hidden services were choosing introduction points uniquely by
          hexdigest, but when constructing the hidden service descriptor
          they merely wrote the (potentially ambiguous) nickname.
        - Clients now use the v2 intro format for hidden service
          connections: they specify their chosen rendezvous point by identity
          digest rather than by (potentially ambiguous) nickname. These
          changes could speed up hidden service connections dramatically.
    
      o Major bugfixes (other):
        - Stop publishing a new server descriptor just because we get a
          HUP signal. This led (in a roundabout way) to some servers getting
          dropped from the networkstatus lists for a few hours each day.
        - When looking for a circuit to cannibalize, consider family as well
          as identity. Fixes bug 438. Bugfix on 0.1.0.x (which introduced
          circuit cannibalization).
        - When a router wasn't listed in a new networkstatus, we were leaving
          the flags for that router alone -- meaning it remained Named,
          Running, etc -- even though absence from the networkstatus means
          that it shouldn't be considered to exist at all anymore. Now we
          clear all the flags for routers that fall out of the networkstatus
          consensus. Fixes bug 529.
    
      o Minor bugfixes:
        - Don't try to access (or alter) the state file when running
          --list-fingerprint or --verify-config or --hash-password. Resolves
          bug 499.
        - When generating information telling us how to extend to a given
          router, do not try to include the nickname if it is
          absent. Resolves bug 467.
        - Fix a user-triggerable segfault in expand_filename(). (There isn't
          a way to trigger this remotely.)
        - When sending a status event to the controller telling it that an
          OR address is reachable, set the port correctly. (Previously we
          were reporting the dir port.)
        - Fix a minor memory leak whenever a controller sends the PROTOCOLINFO
          command. Bugfix on 0.1.2.17.
        - When loading bandwidth history, do not believe any information in
          the future. Fixes bug 434.
        - When loading entry guard information, do not believe any information
          in the future.
        - When we have our clock set far in the future and generate an
          onion key, then re-set our clock to be correct, we should not stop
          the onion key from getting rotated.
        - On some platforms, accept() can return a broken address. Detect
          this more quietly, and deal accordingly. Fixes bug 483.
        - It's not actually an error to find a non-pending entry in the DNS
          cache when canceling a pending resolve. Don't log unless stuff
          is fishy. Resolves bug 463.
        - Don't reset trusted dir server list when we set a configuration
          option. Patch from Robert Hogan.
    
    
    Changes in version 0.1.2.17 - 2007-08-30
      Tor 0.1.2.17 features a new Vidalia version in the Windows and OS
      X bundles. Vidalia 0.0.14 makes authentication required for the
      ControlPort in the default configuration, which addresses important
      security risks. Everybody who uses Vidalia (or another controller)
      should upgrade.
    
      In addition, this Tor update fixes major load balancing problems with
      path selection, which should speed things up a lot once many people
      have upgraded.
    
      o Major bugfixes (security):
        - We removed support for the old (v0) control protocol. It has been
          deprecated since Tor 0.1.1.1-alpha, and keeping it secure has
          become more of a headache than it's worth.
    
      o Major bugfixes (load balancing):
        - When choosing nodes for non-guard positions, weight guards
          proportionally less, since they already have enough load. Patch
          from Mike Perry.
        - Raise the "max believable bandwidth" from 1.5MB/s to 10MB/s. This
          will allow fast Tor servers to get more attention.
        - When we're upgrading from an old Tor version, forget our current
          guards and pick new ones according to the new weightings. These
          three load balancing patches could raise effective network capacity
          by a factor of four. Thanks to Mike Perry for measurements.
    
      o Major bugfixes (stream expiration):
        - Expire not-yet-successful application streams in all cases if
          they've been around longer than SocksTimeout. Right now there are
          some cases where the stream will live forever, demanding a new
          circuit every 15 seconds. Fixes bug 454; reported by lodger.
    
      o Minor features (controller):
        - Add a PROTOCOLINFO controller command. Like AUTHENTICATE, it
          is valid before any authentication has been received. It tells
          a controller what kind of authentication is expected, and what
          protocol is spoken. Implements proposal 119.
    
      o Minor bugfixes (performance):
        - Save on most routerlist_assert_ok() calls in routerlist.c, thus
          greatly speeding up loading cached-routers from disk on startup.
        - Disable sentinel-based debugging for buffer code: we squashed all
          the bugs that this was supposed to detect a long time ago, and now
          its only effect is to change our buffer sizes from nice powers of
          two (which platform mallocs tend to like) to values slightly over
          powers of two (which make some platform mallocs sad).
    
      o Minor bugfixes (misc):
        - If exit bandwidth ever exceeds one third of total bandwidth, then
          use the correct formula to weight exit nodes when choosing paths.
          Based on patch from Mike Perry.
        - Choose perfectly fairly among routers when choosing by bandwidth and
          weighting by fraction of bandwidth provided by exits. Previously, we
          would choose with only approximate fairness, and correct ourselves
          if we ran off the end of the list.
        - If we require CookieAuthentication but we fail to write the
          cookie file, we would warn but not exit, and end up in a state
          where no controller could authenticate. Now we exit.
        - If we require CookieAuthentication, stop generating a new cookie
          every time we change any piece of our config.
        - Refuse to start with certain directory authority keys, and
          encourage people using them to stop.
        - Terminate multi-line control events properly. Original patch
          from tup.
        - Fix a minor memory leak when we fail to find enough suitable
          servers to choose a circuit.
        - Stop leaking part of the descriptor when we run into a particularly
          unparseable piece of it.
    
    
    Changes in version 0.1.2.16 - 2007-08-01
      Tor 0.1.2.16 fixes a critical security vulnerability that allows a
      remote attacker in certain situations to rewrite the user's torrc
      configuration file. This can completely compromise anonymity of users
      in most configurations, including those running the Vidalia bundles,
      TorK, etc. Or worse.
    
      o Major security fixes:
        - Close immediately after missing authentication on control port;
          do not allow multiple authentication attempts.
    
    
    Changes in version 0.1.2.15 - 2007-07-17
      Tor 0.1.2.15 fixes several crash bugs, fixes some anonymity-related
      problems, fixes compilation on BSD, and fixes a variety of other
      bugs. Everybody should upgrade.
    
      o Major bugfixes (compilation):
        - Fix compile on FreeBSD/NetBSD/OpenBSD. Oops.
    
      o Major bugfixes (crashes):
        - Try even harder not to dereference the first character after
          an mmap(). Reported by lodger.
        - Fix a crash bug in directory authorities when we re-number the
          routerlist while inserting a new router.
        - When the cached-routers file is an even multiple of the page size,
          don't run off the end and crash. (Fixes bug 455; based on idea
          from croup.)
        - Fix eventdns.c behavior on Solaris: It is critical to include
          orconfig.h _before_ sys/types.h, so that we can get the expected
          definition of _FILE_OFFSET_BITS.
    
      o Major bugfixes (security):
        - Fix a possible buffer overrun when using BSD natd support. Bug
          found by croup.
        - When sending destroy cells from a circuit's origin, don't include
          the reason for tearing down the circuit. The spec says we didn't,
          and now we actually don't. Reported by lodger.
        - Keep streamids from different exits on a circuit separate. This
          bug may have allowed other routers on a given circuit to inject
          cells into streams. Reported by lodger; fixes bug 446.
        - If there's a never-before-connected-to guard node in our list,
          never choose any guards past it. This way we don't expand our
          guard list unless we need to.
    
      o Minor bugfixes (guard nodes):
        - Weight guard selection by bandwidth, so that low-bandwidth nodes
          don't get overused as guards.
    
      o Minor bugfixes (directory):
        - Correctly count the number of authorities that recommend each
          version. Previously, we were under-counting by 1.
        - Fix a potential crash bug when we load many server descriptors at
          once and some of them make others of them obsolete. Fixes bug 458.
    
      o Minor bugfixes (hidden services):
        - Stop tearing down the whole circuit when the user asks for a
          connection to a port that the hidden service didn't configure.
          Resolves bug 444.
    
      o Minor bugfixes (misc):
        - On Windows, we were preventing other processes from reading
          cached-routers while Tor was running. Reported by janbar.
        - Fix a possible (but very unlikely) bug in picking routers by
          bandwidth. Add a log message to confirm that it is in fact
          unlikely. Patch from lodger.
        - Backport a couple of memory leak fixes.
        - Backport miscellaneous cosmetic bugfixes.
    
    
    Changes in version 0.1.2.14 - 2007-05-25
      Tor 0.1.2.14 changes the addresses of two directory authorities (this
      change especially affects those who serve or use hidden services),
      and fixes several other crash- and security-related bugs.
    
      o Directory authority changes:
        - Two directory authorities (moria1 and moria2) just moved to new
          IP addresses. This change will particularly affect those who serve
          or use hidden services.
    
      o Major bugfixes (crashes):
        - If a directory server runs out of space in the connection table
          as it's processing a begin_dir request, it will free the exit stream
          but leave it attached to the circuit, leading to unpredictable
          behavior. (Reported by seeess, fixes bug 425.)
        - Fix a bug in dirserv_remove_invalid() that would cause authorities
          to corrupt memory under some really unlikely scenarios.
        - Tighten router parsing rules. (Bugs reported by Benedikt Boss.)
        - Avoid segfaults when reading from mmaped descriptor file. (Reported
          by lodger.)
    
      o Major bugfixes (security):
        - When choosing an entry guard for a circuit, avoid using guards
          that are in the same family as the chosen exit -- not just guards
          that are exactly the chosen exit. (Reported by lodger.)
    
      o Major bugfixes (resource management):
        - If a directory authority is down, skip it when deciding where to get
          networkstatus objects or descriptors. Otherwise we keep asking
          every 10 seconds forever. Fixes bug 384.
        - Count it as a failure if we fetch a valid network-status but we
          don't want to keep it. Otherwise we'll keep fetching it and keep
          not wanting to keep it. Fixes part of bug 422.
        - If all of our dirservers have given us bad or no networkstatuses
          lately, then stop hammering them once per minute even when we
          think they're failed. Fixes another part of bug 422.
    
      o Minor bugfixes:
        - Actually set the purpose correctly for descriptors inserted with
          purpose=controller.
        - When we have k non-v2 authorities in our DirServer config,
          we ignored the last k authorities in the list when updating our
          network-statuses.
        - Correctly back-off from requesting router descriptors that we are
          having a hard time downloading.
        - Read resolv.conf files correctly on platforms where read() returns
          partial results on small file reads.
        - Don't rebuild the entire router store every time we get 32K of
          routers: rebuild it when the journal gets very large, or when
          the gaps in the store get very large.
    
      o Minor features:
        - When routers publish SVN revisions in their router descriptors,
          authorities now include those versions correctly in networkstatus
          documents.
        - Warn when using a version of libevent before 1.3b to run a server on
          OSX or BSD: these versions interact badly with userspace threads.
    
    
    Changes in version 0.1.2.13 - 2007-04-24
      This release features some major anonymity fixes, such as safer path
      selection; better client performance; faster bootstrapping, better
      address detection, and better DNS support for servers; write limiting as
      well as read limiting to make servers easier to run; and a huge pile of
      other features and bug fixes. The bundles also ship with Vidalia 0.0.11.
    
      Tor 0.1.2.13 is released in memory of Rob Levin (1955-2006), aka lilo
      of the Freenode IRC network, remembering his patience and vision for
      free speech on the Internet.
    
      o Major features, client performance:
        - Weight directory requests by advertised bandwidth. Now we can
          let servers enable write limiting but still allow most clients to
          succeed at their directory requests. (We still ignore weights when
          choosing a directory authority; I hope this is a feature.)
        - Stop overloading exit nodes -- avoid choosing them for entry or
          middle hops when the total bandwidth available from non-exit nodes
          is much higher than the total bandwidth available from exit nodes.
        - Rather than waiting a fixed amount of time between retrying
          application connections, we wait only 10 seconds for the first,
          10 seconds for the second, and 15 seconds for each retry after
          that. Hopefully this will improve the expected user experience.
        - Sometimes we didn't bother sending a RELAY_END cell when an attempt
          to open a stream fails; now we do in more cases. This should
          make clients able to find a good exit faster in some cases, since
          unhandleable requests will now get an error rather than timing out.
    
      o Major features, client functionality:
        - Implement BEGIN_DIR cells, so we can connect to a directory
          server via TLS to do encrypted directory requests rather than
          plaintext. Enable via the TunnelDirConns and PreferTunneledDirConns
          config options if you like. For now, this feature only works if
          you already have a descriptor for the destination dirserver.
        - Add support for transparent application connections: this basically
          bundles the functionality of trans-proxy-tor into the Tor
          mainline. Now hosts with compliant pf/netfilter implementations
          can redirect TCP connections straight to Tor without diverting
          through SOCKS. (Based on patch from tup.)
        - Add support for using natd; this allows FreeBSDs earlier than
          5.1.2 to have ipfw send connections through Tor without using
          SOCKS. (Patch from Zajcev Evgeny with tweaks from tup.)
    
      o Major features, servers:
        - Setting up a dyndns name for your server is now optional: servers
          with no hostname or IP address will learn their IP address by
          asking the directory authorities. This code only kicks in when you
          would normally have exited with a "no address" error. Nothing's
          authenticated, so use with care.
        - Directory servers now spool server descriptors, v1 directories,
          and v2 networkstatus objects to buffers as needed rather than en
          masse. They also mmap the cached-routers files. These steps save
          lots of memory.
        - Stop requiring clients to have well-formed certificates, and stop
          checking nicknames in certificates. (Clients have certificates so
          that they can look like Tor servers, but in the future we might want
          to allow them to look like regular TLS clients instead. Nicknames
          in certificates serve no purpose other than making our protocol
          easier to recognize on the wire.) Implements proposal 106.
    
      o Improvements on DNS support:
        - Add "eventdns" asynchronous dns library originally based on code
          from Adam Langley. Now we can discard the old rickety dnsworker
          concept, and support a wider variety of DNS functions. Allows
          multithreaded builds on NetBSD and OpenBSD again.
        - Add server-side support for "reverse" DNS lookups (using PTR
          records so clients can determine the canonical hostname for a given
          IPv4 address). Only supported by servers using eventdns; servers
          now announce in their descriptors if they don't support eventdns.
        - Workaround for name servers (like Earthlink's) that hijack failing
          DNS requests and replace the no-such-server answer with a "helpful"
          redirect to an advertising-driven search portal. Also work around
          DNS hijackers who "helpfully" decline to hijack known-invalid
          RFC2606 addresses. Config option "ServerDNSDetectHijacking 0"
          lets you turn it off.
        - Servers now check for the case when common DNS requests are going to
          wildcarded addresses (i.e. all getting the same answer), and change
          their exit policy to reject *:* if it's happening.
        - When asked to resolve a hostname, don't use non-exit servers unless
          requested to do so. This allows servers with broken DNS to be
          useful to the network.
        - Start passing "ipv4" hints to getaddrinfo(), so servers don't do
          useless IPv6 DNS resolves.
        - Specify and implement client-side SOCKS5 interface for reverse DNS
          lookups (see doc/socks-extensions.txt). Also cache them.
        - When we change nameservers or IP addresses, reset and re-launch
          our tests for DNS hijacking.
    
      o Improvements on reachability testing:
        - Servers send out a burst of long-range padding cells once they've
          established that they're reachable. Spread them over 4 circuits,
          so hopefully a few will be fast. This exercises bandwidth and
          bootstraps them into the directory more quickly.
        - When we find our DirPort to be reachable, publish a new descriptor
          so we'll tell the world (reported by pnx).
        - Directory authorities now only decide that routers are reachable
          if their identity keys are as expected.
        - Do DirPort reachability tests less often, since a single test
          chews through many circuits before giving up.
        - Avoid some false positives during reachability testing: don't try
          to test via a server that's on the same /24 network as us.
        - Start publishing one minute or so after we find our ORPort
          to be reachable. This will help reduce the number of descriptors
          we have for ourselves floating around, since it's quite likely
          other things (e.g. DirPort) will change during that minute too.
        - Routers no longer try to rebuild long-term connections to directory
          authorities, and directory authorities no longer try to rebuild
          long-term connections to all servers. We still don't hang up
          connections in these two cases though -- we need to look at it
          more carefully to avoid flapping, and we likely need to wait til
          0.1.1.x is obsolete.
    
      o Improvements on rate limiting:
        - Enable write limiting as well as read limiting. Now we sacrifice
          capacity if we're pushing out lots of directory traffic, rather
          than overrunning the user's intended bandwidth limits.
        - Include TLS overhead when counting bandwidth usage; previously, we
          would count only the bytes sent over TLS, but not the bytes used
          to send them.
        - Servers decline directory requests much more aggressively when
          they're low on bandwidth. Otherwise they end up queueing more and
          more directory responses, which can't be good for latency.
        - But never refuse directory requests from local addresses.
        - Be willing to read or write on local connections (e.g. controller
          connections) even when the global rate limiting buckets are empty.
        - Flush local controller connection buffers periodically as we're
          writing to them, so we avoid queueing 4+ megabytes of data before
          trying to flush.
        - Revise and clean up the torrc.sample that we ship with; add
          a section for BandwidthRate and BandwidthBurst.
    
      o Major features, NT services:
        - Install as NT_AUTHORITY\LocalService rather than as SYSTEM; add a
          command-line flag so that admins can override the default by saying
          "tor --service install --user "SomeUser"". This will not affect
          existing installed services. Also, warn the user that the service
          will look for its configuration file in the service user's
          %appdata% directory. (We can't do the "hardwire the user's appdata
          directory" trick any more, since we may not have read access to that
          directory.)
        - Support running the Tor service with a torrc not in the same
          directory as tor.exe and default to using the torrc located in
          the %appdata%\Tor\ of the user who installed the service. Patch
          from Matt Edman.
        - Add an --ignore-missing-torrc command-line option so that we can
          get the "use sensible defaults if the configuration file doesn't
          exist" behavior even when specifying a torrc location on the
          command line.
        - When stopping an NT service, wait up to 10 sec for it to actually
          stop. (Patch from Matt Edman; resolves bug 295.)
    
      o Directory authority improvements:
        - Stop letting hibernating or obsolete servers affect uptime and
          bandwidth cutoffs.
        - Stop listing hibernating servers in the v1 directory.
        - Authorities no longer recommend exits as guards if this would shift
          too much load to the exit nodes.
        - Authorities now specify server versions in networkstatus. This adds
          about 2% to the size of compressed networkstatus docs, and allows
          clients to tell which servers support BEGIN_DIR and which don't.
          The implementation is forward-compatible with a proposed future
          protocol version scheme not tied to Tor versions.
        - DirServer configuration lines now have an orport= option so
          clients can open encrypted tunnels to the authorities without
          having downloaded their descriptors yet. Enabled for moria1,
          moria2, tor26, and lefkada now in the default configuration.
        - Add a BadDirectory flag to network status docs so that authorities
          can (eventually) tell clients about caches they believe to be
          broken. Not used yet.
        - Allow authorities to list nodes as bad exits in their
          approved-routers file by fingerprint or by address. If most
          authorities set a BadExit flag for a server, clients don't think
          of it as a general-purpose exit. Clients only consider authorities
          that advertise themselves as listing bad exits.
        - Patch from Steve Hildrey: Generate network status correctly on
          non-versioning dirservers.
        - Have directory authorities allow larger amounts of drift in uptime
          without replacing the server descriptor: previously, a server that
          restarted every 30 minutes could have 48 "interesting" descriptors
          per day.
        - Reserve the nickname "Unnamed" for routers that can't pick
          a hostname: any router can call itself Unnamed; directory
          authorities will never allocate Unnamed to any particular router;
          clients won't believe that any router is the canonical Unnamed.
    
      o Directory mirrors and clients:
        - Discard any v1 directory info that's over 1 month old (for
          directories) or over 1 week old (for running-routers lists).
        - Clients track responses with status 503 from dirservers. After a
          dirserver has given us a 503, we try not to use it until an hour has
          gone by, or until we have no dirservers that haven't given us a 503.
        - When we get a 503 from a directory, and we're not a server, we no
          longer count the failure against the total number of failures
          allowed for the object we're trying to download.
        - Prepare for servers to publish descriptors less often: never
          discard a descriptor simply for being too old until either it is
          recommended by no authorities, or until we get a better one for
          the same router. Make caches consider retaining old recommended
          routers for even longer.
        - Directory servers now provide 'Pragma: no-cache' and 'Expires'
          headers for content, so that we can work better in the presence of
          caching HTTP proxies.
        - Stop fetching descriptors if you're not a dir mirror and you
          haven't tried to establish any circuits lately. (This currently
          causes some dangerous behavior, because when you start up again
          you'll use your ancient server descriptors.)
    
      o Major fixes, crashes:
        - Stop crashing when the controller asks us to resetconf more than
          one config option at once. (Vidalia 0.0.11 does this.)
        - Fix a longstanding obscure crash bug that could occur when we run
          out of DNS worker processes, if we're not using eventdns. (Resolves
          bug 390.)
        - Fix an assert that could trigger if a controller quickly set then
          cleared EntryNodes. (Bug found by Udo van den Heuvel.)
        - Avoid crash when telling controller about stream-status and a
          stream is detached.
        - Avoid sending junk to controllers or segfaulting when a controller
          uses EVENT_NEW_DESC with verbose nicknames.
        - Stop triggering asserts if the controller tries to extend hidden
          service circuits (reported by mwenge).
        - If we start a server with ClientOnly 1, then set ClientOnly to 0
          and hup, stop triggering an assert based on an empty onion_key.
        - Mask out all signals in sub-threads; only the libevent signal
          handler should be processing them. This should prevent some crashes
          on some machines using pthreads. (Patch from coderman.)
        - Disable kqueue on OS X 10.3 and earlier, to fix bug 371.
    
      o Major fixes, anonymity/security:
        - Automatically avoid picking more than one node from the same
          /16 network when constructing a circuit. Add an
          "EnforceDistinctSubnets" option to let people disable it if they
          want to operate private test networks on a single subnet.
        - When generating bandwidth history, round down to the nearest
          1k. When storing accounting data, round up to the nearest 1k.
        - When we're running as a server, remember when we last rotated onion
          keys, so that we will rotate keys once they're a week old even if
          we never stay up for a week ourselves.
        - If a client asked for a server by name, and there's a named server
          in our network-status but we don't have its descriptor yet, we
          could return an unnamed server instead.
        - Reject (most) attempts to use Tor circuits with length one. (If
          many people start using Tor as a one-hop proxy, exit nodes become
          a more attractive target for compromise.)
        - Just because your DirPort is open doesn't mean people should be
          able to remotely teach you about hidden service descriptors. Now
          only accept rendezvous posts if you've got HSAuthoritativeDir set.
        - Fix a potential race condition in the rpm installer. Found by
          Stefan Nordhausen.
        - Do not log IPs with TLS failures for incoming TLS
          connections. (Fixes bug 382.)
    
      o Major fixes, other:
        - If our system clock jumps back in time, don't publish a negative
          uptime in the descriptor.
        - When we start during an accounting interval before it's time to wake
          up, remember to wake up at the correct time. (May fix bug 342.)
        - Previously, we would cache up to 16 old networkstatus documents
          indefinitely, if they came from nontrusted authorities. Now we
          discard them if they are more than 10 days old.
        - When we have a state file we cannot parse, tell the user and
          move it aside. Now we avoid situations where the user starts
          Tor in 1904, Tor writes a state file with that timestamp in it,
          the user fixes her clock, and Tor refuses to start.
        - Publish a new descriptor after we hup/reload. This is important
          if our config has changed such that we'll want to start advertising
          our DirPort now, etc.
        - If we are using an exit enclave and we can't connect, e.g. because
          its webserver is misconfigured to not listen on localhost, then
          back off and try connecting from somewhere else before we fail.
    
      o New config options or behaviors:
        - When EntryNodes are configured, rebuild the guard list to contain,
          in order: the EntryNodes that were guards before; the rest of the
          EntryNodes; the nodes that were guards before.
        - Do not warn when individual nodes in the configuration's EntryNodes,
          ExitNodes, etc are down: warn only when all possible nodes
          are down. (Fixes bug 348.)
        - Put a lower-bound on MaxAdvertisedBandwidth.
        - Start using the state file to store bandwidth accounting data:
          the bw_accounting file is now obsolete. We'll keep generating it
          for a while for people who are still using 0.1.2.4-alpha.
        - Try to batch changes to the state file so that we do as few
          disk writes as possible while still storing important things in
          a timely fashion.
        - The state file and the bw_accounting file get saved less often when
          the AvoidDiskWrites config option is set.
        - Make PIDFile work on Windows.
        - Add internal descriptions for a bunch of configuration options:
          accessible via controller interface and in comments in saved
          options files.
        - Reject *:563 (NNTPS) in the default exit policy. We already reject
          NNTP by default, so this seems like a sensible addition.
        - Clients now reject hostnames with invalid characters. This should
          avoid some inadvertent info leaks. Add an option
          AllowNonRFC953Hostnames to disable this behavior, in case somebody
          is running a private network with hosts called @, !, and #.
        - Check for addresses with invalid characters at the exit as well,
          and warn less verbosely when they fail. You can override this by
          setting ServerDNSAllowNonRFC953Addresses to 1.
        - Remove some options that have been deprecated since at least
          0.1.0.x: AccountingMaxKB, LogFile, DebugLogFile, LogLevel, and
          SysLog. Use AccountingMax instead of AccountingMaxKB, and use Log
          to set log options. Mark PathlenCoinWeight as obsolete.
        - Stop accepting certain malformed ports in configured exit policies.
        - When the user uses bad syntax in the Log config line, stop
          suggesting other bad syntax as a replacement.
        - Add new config option "ResolvConf" to let the server operator
          choose an alternate resolve.conf file when using eventdns.
        - If one of our entry guards is on the ExcludeNodes list, or the
          directory authorities don't think it's a good guard, treat it as
          if it were unlisted: stop using it as a guard, and throw it off
          the guards list if it stays that way for a long time.
        - Allow directory authorities to be marked separately as authorities
          for the v1 directory protocol, the v2 directory protocol, and
          as hidden service directories, to make it easier to retire old
          authorities. V1 authorities should set "HSAuthoritativeDir 1"
          to continue being hidden service authorities too.
        - Remove 8888 as a LongLivedPort, and add 6697 (IRCS).
        - Make TrackExitHosts case-insensitive, and fix the behavior of
          ".suffix" TrackExitHosts items to avoid matching in the middle of
          an address.
        - New DirPort behavior: if you have your dirport set, you download
          descriptors aggressively like a directory mirror, whether or not
          your ORPort is set.
    
      o Docs:
        - Create a new file ReleaseNotes which was the old ChangeLog. The
          new ChangeLog file now includes the notes for all development
          versions too.
        - Add a new address-spec.txt document to describe our special-case
          addresses: .exit, .onion, and .noconnnect.
        - Fork the v1 directory protocol into its own spec document,
          and mark dir-spec.txt as the currently correct (v2) spec.
    
      o Packaging, porting, and contrib
        - "tor --verify-config" now exits with -1(255) or 0 depending on
          whether the config options are bad or good.
        - The Debian package now uses --verify-config when (re)starting,
          to distinguish configuration errors from other errors.
        - Adapt a patch from goodell to let the contrib/exitlist script
          take arguments rather than require direct editing.
        - Prevent the contrib/exitlist script from printing the same
          result more than once.
        - Add support to tor-resolve tool for reverse lookups and SOCKS5.
        - In the hidden service example in torrc.sample, stop recommending
          esoteric and discouraged hidden service options.
        - Patch from Michael Mohr to contrib/cross.sh, so it checks more
          values before failing, and always enables eventdns.
        - Try to detect Windows correctly when cross-compiling.
        - Libevent-1.2 exports, but does not define in its headers, strlcpy.
          Try to fix this in configure.in by checking for most functions
          before we check for libevent.
        - Update RPMs to require libevent 1.2.
        - Experimentally re-enable kqueue on OSX when using libevent 1.1b
          or later. Log when we are doing this, so we can diagnose it when
          it fails. (Also, recommend libevent 1.1b for kqueue and
          win32 methods; deprecate libevent 1.0b harder; make libevent
          recommendation system saner.)
        - Build with recent (1.3+) libevents on platforms that do not
          define the nonstandard types "u_int8_t" and friends.
        - Remove architecture from OS X builds. The official builds are
          now universal binaries.
        - Run correctly on OS X platforms with case-sensitive filesystems.
        - Correctly set maximum connection limit on Cygwin. (This time
          for sure!)
        - Start compiling on MinGW on Windows (patches from Mike Chiussi
          and many others).
        - Start compiling on MSVC6 on Windows (patches from Frediano Ziglio).
        - Finally fix the openssl warnings from newer gccs that believe that
          ignoring a return value is okay, but casting a return value and
          then ignoring it is a sign of madness.
        - On architectures where sizeof(int)>4, still clamp declarable
          bandwidth to INT32_MAX.
    
      o Minor features, controller:
        - Warn the user when an application uses the obsolete binary v0
          control protocol. We're planning to remove support for it during
          the next development series, so it's good to give people some
          advance warning.
        - Add STREAM_BW events to report per-entry-stream bandwidth
          use. (Patch from Robert Hogan.)
        - Rate-limit SIGNEWNYM signals in response to controllers that
          impolitely generate them for every single stream. (Patch from
          mwenge; closes bug 394.)
        - Add a REMAP status to stream events to note that a stream's
          address has changed because of a cached address or a MapAddress
          directive.
        - Make REMAP stream events have a SOURCE (cache or exit), and
          make them generated in every case where we get a successful
          connected or resolved cell.
        - Track reasons for OR connection failure; make these reasons
          available via the controller interface. (Patch from Mike Perry.)
        - Add a SOCKS_BAD_HOSTNAME client status event so controllers
          can learn when clients are sending malformed hostnames to Tor.
        - Specify and implement some of the controller status events.
        - Have GETINFO dir/status/* work on hosts with DirPort disabled.
        - Reimplement GETINFO so that info/names stays in sync with the
          actual keys.
        - Implement "GETINFO fingerprint".
        - Implement "SETEVENTS GUARD" so controllers can get updates on
          entry guard status as it changes.
        - Make all connections to addresses of the form ".noconnect"
          immediately get closed. This lets application/controller combos
          successfully test whether they're talking to the same Tor by
          watching for STREAM events.
        - Add a REASON field to CIRC events; for backward compatibility, this
          field is sent only to controllers that have enabled the extended
          event format. Also, add additional reason codes to explain why
          a given circuit has been destroyed or truncated. (Patches from
          Mike Perry)
        - Add a REMOTE_REASON field to extended CIRC events to tell the
          controller why a remote OR told us to close a circuit.
        - Stream events also now have REASON and REMOTE_REASON fields,
          working much like those for circuit events.
        - There's now a GETINFO ns/... field so that controllers can ask Tor
          about the current status of a router.
        - A new event type "NS" to inform a controller when our opinion of
          a router's status has changed.
        - Add a GETINFO events/names and GETINFO features/names so controllers
          can tell which events and features are supported.
        - A new CLEARDNSCACHE signal to allow controllers to clear the
          client-side DNS cache without expiring circuits.
        - Fix CIRC controller events so that controllers can learn the
          identity digests of non-Named servers used in circuit paths.
        - Let controllers ask for more useful identifiers for servers. Instead
          of learning identity digests for un-Named servers and nicknames
          for Named servers, the new identifiers include digest, nickname,
          and indication of Named status. Off by default; see control-spec.txt
          for more information.
        - Add a "getinfo address" controller command so it can display Tor's
          best guess to the user.
        - New controller event to alert the controller when our server
          descriptor has changed.
        - Give more meaningful errors on controller authentication failure.
        - Export the default exit policy via the control port, so controllers
          don't need to guess what it is / will be later.
    
      o Minor bugfixes, controller:
        - When creating a circuit via the controller, send a 'launched'
          event when we're done, so we follow the spec better.
        - Correct the control spec to match how the code actually responds
          to 'getinfo addr-mappings/*'. Reported by daejees.
        - The control spec described a GUARDS event, but the code
          implemented a GUARD event. Standardize on GUARD, but let people
          ask for GUARDS too. Reported by daejees.
        - Give the controller END_STREAM_REASON_DESTROY events _before_ we
          clear the corresponding on_circuit variable, and remember later
          that we don't need to send a redundant CLOSED event. (Resolves part
          3 of bug 367.)
        - Report events where a resolve succeeded or where we got a socks
          protocol error correctly, rather than calling both of them
          "INTERNAL".
        - Change reported stream target addresses to IP consistently when
          we finally get the IP from an exit node.
        - Send log messages to the controller even if they happen to be very
          long.
        - Flush ERR-level controller status events just like we currently
          flush ERR-level log events, so that a Tor shutdown doesn't prevent
          the controller from learning about current events.
        - Report the circuit number correctly in STREAM CLOSED events. Bug
          reported by Mike Perry.
        - Do not report bizarre values for results of accounting GETINFOs
          when the last second's write or read exceeds the allotted bandwidth.
        - Report "unrecognized key" rather than an empty string when the
          controller tries to fetch a networkstatus that doesn't exist.
        - When the controller does a "GETINFO network-status", tell it
          about even those routers whose descriptors are very old, and use
          long nicknames where appropriate.
        - Fix handling of verbose nicknames with ORCONN controller events:
          make them show up exactly when requested, rather than exactly when
          not requested.
        - Controller signals now work on non-Unix platforms that don't define
          SIGUSR1 and SIGUSR2 the way we expect.
        - Respond to SIGNAL command before we execute the signal, in case
          the signal shuts us down. Suggested by Karsten Loesing.
        - Handle reporting OR_CONN_EVENT_NEW events to the controller.
    
      o Minor features, code performance:
        - Major performance improvement on inserting descriptors: change
          algorithm from O(n^2) to O(n).
        - Do not rotate onion key immediately after setting it for the first
          time.
        - Call router_have_min_dir_info half as often. (This is showing up in
          some profiles, but not others.)
        - When using GCC, make log_debug never get called at all, and its
          arguments never get evaluated, when no debug logs are configured.
          (This is showing up in some profiles, but not others.)
        - Statistics dumped by -USR2 now include a breakdown of public key
          operations, for profiling.
        - Make the common memory allocation path faster on machines where
          malloc(0) returns a pointer.
        - Split circuit_t into origin_circuit_t and or_circuit_t, and
          split connection_t into edge, or, dir, control, and base structs.
          These will save quite a bit of memory on busy servers, and they'll
          also help us track down bugs in the code and bugs in the spec.
        - Use OpenSSL's AES implementation on platforms where it's faster.
          This could save us as much as 10% CPU usage.
    
      o Minor features, descriptors and descriptor handling:
        - Avoid duplicate entries on MyFamily line in server descriptor.
        - When Tor receives a router descriptor that it asked for, but
          no longer wants (because it has received fresh networkstatuses
          in the meantime), do not warn the user. Cache the descriptor if
          we're a cache; drop it if we aren't.
        - Servers no longer ever list themselves in their "family" line,
          even if configured to do so. This makes it easier to configure
          family lists conveniently.
    
      o Minor fixes, confusing/misleading log messages:
        - Display correct results when reporting which versions are
          recommended, and how recommended they are. (Resolves bug 383.)
        - Inform the server operator when we decide not to advertise a
          DirPort due to AccountingMax enabled or a low BandwidthRate.
        - Only include function names in log messages for info/debug messages.
          For notice/warn/err, the content of the message should be clear on
          its own, and printing the function name only confuses users.
        - Remove even more protocol-related warnings from Tor server logs,
          such as bad TLS handshakes and malformed begin cells.
        - Fix bug 314: Tor clients issued "unsafe socks" warnings even
          when the IP address is mapped through MapAddress to a hostname.
        - Fix misleading log messages: an entry guard that is "unlisted",
          as well as not known to be "down" (because we've never heard
          of it), is not therefore "up".
    
      o Minor fixes, old/obsolete behavior:
        - Start assuming we can use a create_fast cell if we don't know
          what version a router is running.
        - We no longer look for identity and onion keys in "identity.key" and
          "onion.key" -- these were replaced by secret_id_key and
          secret_onion_key in 0.0.8pre1.
        - We no longer require unrecognized directory entries to be
          preceded by "opt".
        - Drop compatibility with obsolete Tors that permit create cells
          to have the wrong circ_id_type.
        - Remove code to special-case "-cvs" ending, since it has not
          actually mattered since 0.0.9.
        - Don't re-write the fingerprint file every restart, unless it has
          changed.
    
      o Minor fixes, misc client-side behavior:
        - Always remove expired routers and networkstatus docs before checking
          whether we have enough information to build circuits. (Fixes
          bug 373.)
        - When computing clock skew from directory HTTP headers, consider what
          time it was when we finished asking for the directory, not what
          time it is now.
        - Make our socks5 handling more robust to broken socks clients:
          throw out everything waiting on the buffer in between socks
          handshake phases, since they can't possibly (so the theory
          goes) have predicted what we plan to respond to them.
        - Expire socks connections if they spend too long waiting for the
          handshake to finish. Previously we would let them sit around for
          days, if the connecting application didn't close them either.
        - And if the socks handshake hasn't started, don't send a
          "DNS resolve socks failed" handshake reply; just close it.
        - If the user asks to use invalid exit nodes, be willing to use
          unstable ones.
        - Track unreachable entry guards correctly: don't conflate
          'unreachable by us right now' with 'listed as down by the directory
          authorities'. With the old code, if a guard was unreachable by us
          but listed as running, it would clog our guard list forever.
        - Behave correctly in case we ever have a network with more than
          2GB/s total advertised capacity.
        - Claim a commonname of Tor, rather than TOR, in TLS handshakes.
        - Fix a memory leak when we ask for "all" networkstatuses and we
          get one we don't recognize.
    
    
    Changes in version 0.1.1.26 - 2006-12-14
      o Security bugfixes:
        - Stop sending the HttpProxyAuthenticator string to directory
          servers when directory connections are tunnelled through Tor.
        - Clients no longer store bandwidth history in the state file.
        - Do not log introduction points for hidden services if SafeLogging
          is set.
    
      o Minor bugfixes:
        - Fix an assert failure when a directory authority sets
          AuthDirRejectUnlisted and then receives a descriptor from an
          unlisted router (reported by seeess).
    
    
    Changes in version 0.1.1.25 - 2006-11-04
      o Major bugfixes:
        - When a client asks us to resolve (rather than connect to)
          an address, and we have a cached answer, give them the cached
          answer. Previously, we would give them no answer at all.
        - We were building exactly the wrong circuits when we predict
          hidden service requirements, meaning Tor would have to build all
          its circuits on demand.
        - If none of our live entry guards have a high uptime, but we
          require a guard with a high uptime, try adding a new guard before
          we give up on the requirement. This patch should make long-lived
          connections more stable on average.
        - When testing reachability of our DirPort, don't launch new
          tests when there's already one in progress -- unreachable
          servers were stacking up dozens of testing streams.
    
      o Security bugfixes:
        - When the user sends a NEWNYM signal, clear the client-side DNS
          cache too. Otherwise we continue to act on previous information.
    
      o Minor bugfixes:
        - Avoid a memory corruption bug when creating a hash table for
          the first time.
        - Avoid possibility of controller-triggered crash when misusing
          certain commands from a v0 controller on platforms that do not
          handle printf("%s",NULL) gracefully.
        - Avoid infinite loop on unexpected controller input.
        - Don't log spurious warnings when we see a circuit close reason we
          don't recognize; it's probably just from a newer version of Tor.
        - Add Vidalia to the OS X uninstaller script, so when we uninstall
          Tor/Privoxy we also uninstall Vidalia.
    
    
    Changes in version 0.1.1.24 - 2006-09-29
      o Major bugfixes:
        - Allow really slow clients to not hang up five minutes into their
          directory downloads (suggested by Adam J. Richter).
        - Fix major performance regression from 0.1.0.x: instead of checking
          whether we have enough directory information every time we want to
          do something, only check when the directory information has changed.
          This should improve client CPU usage by 25-50%.
        - Don't crash if, after a server has been running for a while,
          it can't resolve its hostname.
        - When a client asks us to resolve (not connect to) an address,
          and we have a cached answer, give them the cached answer.
          Previously, we would give them no answer at all.
    
      o Minor bugfixes:
        - Allow Tor to start when RunAsDaemon is set but no logs are set.
        - Don't crash when the controller receives a third argument to an
          "extendcircuit" request.
        - Controller protocol fixes: fix encoding in "getinfo addr-mappings"
          response; fix error code when "getinfo dir/status/" fails.
        - Fix configure.in to not produce broken configure files with
          more recent versions of autoconf. Thanks to Clint for his auto*
          voodoo.
        - Fix security bug on NetBSD that could allow someone to force
          uninitialized RAM to be sent to a server's DNS resolver. This
          only affects NetBSD and other platforms that do not bounds-check
          tolower().
        - Warn user when using libevent 1.1a or earlier with win32 or kqueue
          methods: these are known to be buggy.
        - If we're a directory mirror and we ask for "all" network status
          documents, we would discard status documents from authorities
          we don't recognize.
    
    
    Changes in version 0.1.1.23 - 2006-07-30
      o Major bugfixes:
        - Fast Tor servers, especially exit nodes, were triggering asserts
          due to a bug in handling the list of pending DNS resolves. Some
          bugs still remain here; we're hunting them.
        - Entry guards could crash clients by sending unexpected input.
        - More fixes on reachability testing: if you find yourself reachable,
          then don't ever make any client requests (so you stop predicting
          circuits), then hup or have your clock jump, then later your IP
          changes, you won't think circuits are working, so you won't try to
          test reachability, so you won't publish.
    
      o Minor bugfixes:
        - Avoid a crash if the controller does a resetconf firewallports
          and then a setconf fascistfirewall=1.
        - Avoid an integer underflow when the dir authority decides whether
          a router is stable: we might wrongly label it stable, and compute
          a slightly wrong median stability, when a descriptor is published
          later than now.
        - Fix a place where we might trigger an assert if we can't build our
          own server descriptor yet.
    
    
    Changes in version 0.1.1.22 - 2006-07-05
      o Major bugfixes:
        - Fix a big bug that was causing servers to not find themselves
          reachable if they changed IP addresses. Since only 0.1.1.22+
          servers can do reachability testing correctly, now we automatically
          make sure to test via one of these.
        - Fix to allow clients and mirrors to learn directory info from
          descriptor downloads that get cut off partway through.
        - Directory authorities had a bug in deciding if a newly published
          descriptor was novel enough to make everybody want a copy -- a few
          servers seem to be publishing new descriptors many times a minute.
      o Minor bugfixes:
        - Fix a rare bug that was causing some servers to complain about
          "closing wedged cpuworkers" and skip some circuit create requests.
        - Make the Exit flag in directory status documents actually work.
    
    
    Changes in version 0.1.1.21 - 2006-06-10
      o Crash and assert fixes from 0.1.1.20:
        - Fix a rare crash on Tor servers that have enabled hibernation.
        - Fix a seg fault on startup for Tor networks that use only one
          directory authority.
        - Fix an assert from a race condition that occurs on Tor servers
          while exiting, where various threads are trying to log that they're
          exiting, and delete the logs, at the same time.
        - Make our unit tests pass again on certain obscure platforms.
    
      o Other fixes:
        - Add support for building SUSE RPM packages.
        - Speed up initial bootstrapping for clients: if we are making our
          first ever connection to any entry guard, then don't mark it down
          right after that.
        - When only one Tor server in the network is labelled as a guard,
          and we've already picked him, we would cycle endlessly picking him
          again, being unhappy about it, etc. Now we specifically exclude
          current guards when picking a new guard.
        - Servers send create cells more reliably after the TLS connection
          is established: we were sometimes forgetting to send half of them
          when we had more than one pending.
        - If we get a create cell that asks us to extend somewhere, but the
          Tor server there doesn't match the expected digest, we now send
          a destroy cell back, rather than silently doing nothing.
        - Make options->RedirectExit work again.
        - Make cookie authentication for the controller work again.
        - Stop being picky about unusual characters in the arguments to
          mapaddress. It's none of our business.
        - Add a new config option "TestVia" that lets you specify preferred
          middle hops to use for test circuits. Perhaps this will let me
          debug the reachability problems better.
    
      o Log / documentation fixes:
        - If we're a server and some peer has a broken TLS certificate, don't
          log about it unless ProtocolWarnings is set, i.e., we want to hear
          about protocol violations by others.
        - Fix spelling of VirtualAddrNetwork in man page.
        - Add a better explanation at the top of the autogenerated torrc file
          about what happened to our old torrc.
    
    
    Changes in version 0.1.1.20 - 2006-05-23
      o Crash and assert fixes from 0.1.0.17:
        - Fix assert bug in close_logs() on exit: when we close and delete
          logs, remove them all from the global "logfiles" list.
        - Fix an assert error when we're out of space in the connection_list
          and we try to post a hidden service descriptor (reported by Peter
          Palfrader).
        - Fix a rare assert error when we've tried all intro points for
          a hidden service and we try fetching the service descriptor again:
          "Assertion conn->state != AP_CONN_STATE_RENDDESC_WAIT failed".
        - Setconf SocksListenAddress kills Tor if it fails to bind. Now back
          out and refuse the setconf if it would fail.
        - If you specify a relative torrc path and you set RunAsDaemon in
          your torrc, then it chdir()'s to the new directory. If you then
          HUP, it tries to load the new torrc location, fails, and exits.
          The fix: no longer allow a relative path to torrc when using -f.
        - Check for integer overflows in more places, when adding elements
          to smartlists. This could possibly prevent a buffer overflow
          on malicious huge inputs.
    
      o Security fixes, major:
        - When we're printing strings from the network, don't try to print
          non-printable characters. Now we're safer against shell escape
          sequence exploits, and also against attacks to fool users into
          misreading their logs.
        - Implement entry guards: automatically choose a handful of entry
          nodes and stick with them for all circuits. Only pick new guards
          when the ones you have are unsuitable, and if the old guards
          become suitable again, switch back. This will increase security
          dramatically against certain end-point attacks. The EntryNodes
          config option now provides some hints about which entry guards you
          want to use most; and StrictEntryNodes means to only use those.
          Fixes CVE-2006-0414.
        - Implement exit enclaves: if we know an IP address for the
          destination, and there's a running Tor server at that address
          which allows exit to the destination, then extend the circuit to
          that exit first. This provides end-to-end encryption and end-to-end
          authentication. Also, if the user wants a .exit address or enclave,
          use 4 hops rather than 3, and cannibalize a general circ for it
          if you can.
        - Obey our firewall options more faithfully:
          . If we can't get to a dirserver directly, try going via Tor.
          . Don't ever try to connect (as a client) to a place our
            firewall options forbid.
          . If we specify a proxy and also firewall options, obey the
            firewall options even when we're using the proxy: some proxies
            can only proxy to certain destinations.
        - Make clients regenerate their keys when their IP address changes.
        - For the OS X package's modified privoxy config file, comment
          out the "logfile" line so we don't log everything passed
          through privoxy.
        - Our TLS handshakes were generating a single public/private
          keypair for the TLS context, rather than making a new one for
          each new connection. Oops. (But we were still rotating them
          periodically, so it's not so bad.)
        - When we were cannibalizing a circuit with a particular exit
          node in mind, we weren't checking to see if that exit node was
          already present earlier in the circuit. Now we are.
        - Require server descriptors to list IPv4 addresses -- hostnames
          are no longer allowed. This also fixes potential vulnerabilities
          to servers providing hostnames as their address and then
          preferentially resolving them so they can partition users.
        - Our logic to decide if the OR we connected to was the right guy
          was brittle and maybe open to a mitm for invalid routers.
    
      o Security fixes, minor:
        - Adjust tor-spec.txt to parameterize cell and key lengths. Now
          Ian Goldberg can prove things about our handshake protocol more
          easily.
        - Make directory authorities generate a separate "guard" flag to
          mean "would make a good entry guard". Clients now honor the
          is_guard flag rather than looking at is_fast or is_stable.
        - Try to list MyFamily elements by key, not by nickname, and warn
          if we've not heard of a server.
        - Start using RAND_bytes rather than RAND_pseudo_bytes from
          OpenSSL. Also, reseed our entropy every hour, not just at
          startup. And add entropy in 512-bit chunks, not 160-bit chunks.
        - Refuse server descriptors where the fingerprint line doesn't match
          the included identity key. Tor doesn't care, but other apps (and
          humans) might actually be trusting the fingerprint line.
        - We used to kill the circuit when we receive a relay command we
          don't recognize. Now we just drop that cell.
        - Fix a bug found by Lasse Overlier: when we were making internal
          circuits (intended to be cannibalized later for rendezvous and
          introduction circuits), we were picking them so that they had
          useful exit nodes. There was no need for this, and it actually
          aids some statistical attacks.
        - Start treating internal circuits and exit circuits separately.
          It's important to keep them separate because internal circuits
          have their last hops picked like middle hops, rather than like
          exit hops. So exiting on them will break the user's expectations.
        - Fix a possible way to DoS dirservers.
        - When the client asked for a rendezvous port that the hidden
          service didn't want to provide, we were sending an IP address
          back along with the end cell. Fortunately, it was zero. But stop
          that anyway.
    
      o Packaging improvements:
        - Implement --with-libevent-dir option to ./configure. Improve
          search techniques to find libevent, and use those for openssl too.
        - Fix a couple of bugs in OpenSSL detection. Deal better when
          there are multiple SSLs installed with different versions.
        - Avoid warnings about machine/limits.h on Debian GNU/kFreeBSD.
        - On non-gcc compilers (e.g. Solaris's cc), use "-g -O" instead of
          "-Wall -g -O2".
        - Make unit tests (and other invocations that aren't the real Tor)
          run without launching listeners, creating subdirectories, and so on.
        - The OS X installer was adding a symlink for tor_resolve but
          the binary was called tor-resolve (reported by Thomas Hardly).
        - Now we can target arch and OS in rpm builds (contributed by
          Phobos). Also make the resulting dist-rpm filename match the
          target arch.
        - Apply Matt Ghali's --with-syslog-facility patch to ./configure
          if you log to syslog and want something other than LOG_DAEMON.
        - Fix the torify (tsocks) config file to not use Tor for localhost
          connections.
        - Start shipping socks-extensions.txt, tor-doc-unix.html,
          tor-doc-server.html, and stylesheet.css in the tarball.
        - Stop shipping tor-doc.html, INSTALL, and README in the tarball.
          They are useless now.
        - Add Peter Palfrader's contributed check-tor script. It lets you
          easily check whether a given server (referenced by nickname)
          is reachable by you.
        - Add BSD-style contributed startup script "rc.subr" from Peter
          Thoenen.
    
      o Directory improvements -- new directory protocol:
        - See tor/doc/dir-spec.txt for all the juicy details. Key points:
        - Authorities and caches publish individual descriptors (by
          digest, by fingerprint, by "all", and by "tell me yours").
        - Clients don't download or use the old directory anymore. Now they
          download network-statuses from the directory authorities, and
          fetch individual server descriptors as needed from mirrors.
        - Clients don't download descriptors of non-running servers.
        - Download descriptors by digest, not by fingerprint. Caches try to
          download all listed digests from authorities; clients try to
          download "best" digests from caches. This avoids partitioning
          and isolating attacks better.
        - Only upload a new server descriptor when options change, 18
          hours have passed, uptime is reset, or bandwidth changes a lot.
        - Directory authorities silently throw away new descriptors that
          haven't changed much if the timestamps are similar. We do this to
          tolerate older Tor servers that upload a new descriptor every 15
          minutes. (It seemed like a good idea at the time.)
        - Clients choose directory servers from the network status lists,
          not from their internal list of router descriptors. Now they can
          go to caches directly rather than needing to go to authorities
          to bootstrap the first set of descriptors.
        - When picking a random directory, prefer non-authorities if any
          are known.
        - Add a new flag to network-status indicating whether the server
          can answer v2 directory requests too.
        - Directory mirrors now cache up to 16 unrecognized network-status
          docs, so new directory authorities will be cached too.
        - Stop parsing, storing, or using running-routers output (but
          mirrors still cache and serve it).
        - Clients consider a threshold of "versioning" directory authorities
          before deciding whether to warn the user that he's obsolete.
        - Authorities publish separate sorted lists of recommended versions
          for clients and for servers.
        - Change DirServers config line to note which dirs are v1 authorities.
        - Put nicknames on the DirServer line, so we can refer to them
          without requiring all our users to memorize their IP addresses.
        - Remove option when getting directory cache to see whether they
          support running-routers; they all do now. Replace it with one
          to see whether caches support v2 stuff.
        - Stop listing down or invalid nodes in the v1 directory. This
          reduces its bulk by about 1/3, and reduces load on mirrors.
        - Mirrors no longer cache the v1 directory as often.
        - If we as a directory mirror don't know of any v1 directory
          authorities, then don't try to cache any v1 directories.
    
      o Other directory improvements:
        - Add lefkada.eecs.harvard.edu and tor.dizum.com as fourth and
          fifth authoritative directory servers.
        - Directory authorities no longer require an open connection from
          a server to consider him "reachable". We need this change because
          when we add new directory authorities, old servers won't know not
          to hang up on them.
        - Dir authorities now do their own external reachability testing
          of each server, and only list as running the ones they found to
          be reachable. We also send back warnings to the server's logs if
          it uploads a descriptor that we already believe is unreachable.
        - Spread the directory authorities' reachability testing over the
          entire testing interval, so we don't try to do 500 TLS's at once
          every 20 minutes.
        - Make the "stable" router flag in network-status be the median of
          the uptimes of running valid servers, and make clients pay
          attention to the network-status flags. Thus the cutoff adapts
          to the stability of the network as a whole, making IRC, IM, etc
          connections more reliable.
        - Make the v2 dir's "Fast" flag based on relative capacity, just
          like "Stable" is based on median uptime. Name everything in the
          top 7/8 Fast, and only the top 1/2 gets to be a Guard.
        - Retry directory requests if we fail to get an answer we like
          from a given dirserver (we were retrying before, but only if
          we fail to connect).
        - Return a robots.txt on our dirport to discourage google indexing.
    
      o Controller protocol improvements:
        - Revised controller protocol (version 1) that uses ascii rather
          than binary: tor/doc/control-spec.txt. Add supporting libraries
          in python and java and c# so you can use the controller from your
          applications without caring how our protocol works.
        - Allow the DEBUG controller event to work again. Mark certain log
          entries as "don't tell this to controllers", so we avoid cycles.
        - New controller function "getinfo accounting", to ask how
          many bytes we've used in this time period.
        - Add a "resetconf" command so you can set config options like
          AllowUnverifiedNodes and LongLivedPorts to "". Also, if you give
          a config option in the torrc with no value, then it clears it
          entirely (rather than setting it to its default).
        - Add a "getinfo config-file" to tell us where torrc is. Also
          expose guard nodes, config options/names.
        - Add a "quit" command (when when using the controller manually).
        - Add a new signal "newnym" to "change pseudonyms" -- that is, to
          stop using any currently-dirty circuits for new streams, so we
          don't link new actions to old actions. This also occurs on HUP
          or "signal reload".
        - If we would close a stream early (e.g. it asks for a .exit that
          we know would refuse it) but the LeaveStreamsUnattached config
          option is set by the controller, then don't close it.
        - Add a new controller event type "authdir_newdescs" that allows
          controllers to get all server descriptors that were uploaded to
          a router in its role as directory authority.
        - New controller option "getinfo desc/all-recent" to fetch the
          latest server descriptor for every router that Tor knows about.
        - Fix the controller's "attachstream 0" command to treat conn like
          it just connected, doing address remapping, handling .exit and
          .onion idioms, and so on. Now we're more uniform in making sure
          that the controller hears about new and closing connections.
        - Permit transitioning from ORPort==0 to ORPort!=0, and back, from
          the controller. Also, rotate dns and cpu workers if the controller
          changes options that will affect them; and initialize the dns
          worker cache tree whether or not we start out as a server.
        - Add a new circuit purpose 'controller' to let the controller ask
          for a circuit that Tor won't try to use. Extend the "extendcircuit"
          controller command to let you specify the purpose if you're starting
          a new circuit.  Add a new "setcircuitpurpose" controller command to
          let you change a circuit's purpose after it's been created.
        - Let the controller ask for "getinfo dir/server/foo" so it can ask
          directly rather than connecting to the dir port. "getinfo
          dir/status/foo" also works, but currently only if your DirPort
          is enabled.
        - Let the controller tell us about certain router descriptors
          that it doesn't want Tor to use in circuits. Implement
          "setrouterpurpose" and modify "+postdescriptor" to do this.
        - If the controller's *setconf commands fail, collect an error
          message in a string and hand it back to the controller -- don't
          just tell them to go read their logs.
    
      o Scalability, resource management, and performance:
        - Fix a major load balance bug: we were round-robin reading in 16 KB
          chunks, and servers with bandwidthrate of 20 KB, while downloading
          a 600 KB directory, would starve their other connections. Now we
          try to be a bit more fair.
        - Be more conservative about whether to advertise our DirPort.
          The main change is to not advertise if we're running at capacity
          and either a) we could hibernate ever or b) our capacity is low
          and we're using a default DirPort.
        - We weren't cannibalizing circuits correctly for
          CIRCUIT_PURPOSE_C_ESTABLISH_REND and
          CIRCUIT_PURPOSE_S_ESTABLISH_INTRO, so we were being forced to
          build those from scratch. This should make hidden services faster.
        - Predict required circuits better, with an eye toward making hidden
          services faster on the service end.
        - Compress exit policies even more: look for duplicate lines and
          remove them.
        - Generate 18.0.0.0/8 address policy format in descs when we can;
          warn when the mask is not reducible to a bit-prefix.
        - There used to be two ways to specify your listening ports in a
          server descriptor: on the "router" line and with a separate "ports"
          line. Remove support for the "ports" line.
        - Reduce memory requirements in our structs by changing the order
          of fields. Replace balanced trees with hash tables. Inline
          bottleneck smartlist functions. Add a "Map from digest to void*"
          abstraction so we can do less hex encoding/decoding, and use it
          in router_get_by_digest(). Many other CPU and memory improvements.
        - Allow tor_gzip_uncompress to extract as much as possible from
          truncated compressed data. Try to extract as many
          descriptors as possible from truncated http responses (when
          purpose is DIR_PURPOSE_FETCH_ROUTERDESC).
        - Make circ->onionskin a pointer, not a static array. moria2 was using
          125000 circuit_t's after it had been up for a few weeks, which
          translates to 20+ megs of wasted space.
        - The private half of our EDH handshake keys are now chosen out
          of 320 bits, not 1024 bits. (Suggested by Ian Goldberg.)
        - Stop doing the complex voodoo overkill checking for insecure
          Diffie-Hellman keys. Just check if it's in [2,p-2] and be happy.
        - Do round-robin writes for TLS of at most 16 kB per write. This
          might be more fair on loaded Tor servers.
        - Do not use unaligned memory access on alpha, mips, or mipsel.
          It *works*, but is very slow, so we treat them as if it doesn't.
    
      o Other bugfixes and improvements:
        - Start storing useful information to $DATADIR/state, so we can
          remember things across invocations of Tor. Retain unrecognized
          lines so we can be forward-compatible, and write a TorVersion line
          so we can be backward-compatible.
        - If ORPort is set, Address is not explicitly set, and our hostname
          resolves to a private IP address, try to use an interface address
          if it has a public address. Now Windows machines that think of
          themselves as localhost can guess their address.
        - Regenerate our local descriptor if it's dirty and we try to use
          it locally (e.g. if it changes during reachability detection).
          This was causing some Tor servers to keep publishing the same
          initial descriptor forever.
        - Tor servers with dynamic IP addresses were needing to wait 18
          hours before they could start doing reachability testing using
          the new IP address and ports. This is because they were using
          the internal descriptor to learn what to test, yet they were only
          rebuilding the descriptor once they decided they were reachable.
        - It turns out we couldn't bootstrap a network since we added
          reachability detection in 0.1.0.1-rc. Good thing the Tor network
          has never gone down. Add an AssumeReachable config option to let
          servers and authorities bootstrap. When we're trying to build a
          high-uptime or high-bandwidth circuit but there aren't enough
          suitable servers, try being less picky rather than simply failing.
        - Newly bootstrapped Tor networks couldn't establish hidden service
          circuits until they had nodes with high uptime. Be more tolerant.
        - Really busy servers were keeping enough circuits open on stable
          connections that they were wrapping around the circuit_id
          space. (It's only two bytes.) This exposed a bug where we would
          feel free to reuse a circuit_id even if it still exists but has
          been marked for close. Try to fix this bug. Some bug remains.
        - When we fail to bind or listen on an incoming or outgoing
          socket, we now close it before refusing, rather than just
          leaking it. (Thanks to Peter Palfrader for finding.)
        - Fix a file descriptor leak in start_daemon().
        - On Windows, you can't always reopen a port right after you've
          closed it. So change retry_listeners() to only close and re-open
          ports that have changed.
        - Workaround a problem with some http proxies that refuse GET
          requests that specify "Content-Length: 0". Reported by Adrian.
        - Recover better from TCP connections to Tor servers that are
          broken but don't tell you (it happens!); and rotate TLS
          connections once a week.
        - Fix a scary-looking but apparently harmless bug where circuits
          would sometimes start out in state CIRCUIT_STATE_OR_WAIT at
          servers, and never switch to state CIRCUIT_STATE_OPEN.
        - Check for even more Windows version flags when writing the platform
          string in server descriptors, and note any we don't recognize.
        - Add reasons to DESTROY and RELAY_TRUNCATED cells, so clients can
          get a better idea of why their circuits failed. Not used yet.
        - Add TTLs to RESOLVED, CONNECTED, and END_REASON_EXITPOLICY cells.
          We don't use them yet, but maybe one day our DNS resolver will be
          able to discover them.
        - Let people type "tor --install" as well as "tor -install" when they
          want to make it an NT service.
        - Looks like we were never delivering deflated (i.e. compressed)
          running-routers lists, even when asked. Oops.
        - We were leaking some memory every time the client changed IPs.
        - Clean up more of the OpenSSL memory when exiting, so we can detect
          memory leaks better.
        - Never call free() on tor_malloc()d memory. This will help us
          use dmalloc to detect memory leaks.
        - Some Tor servers process billions of cells per day. These
          statistics are now uint64_t's.
        - Check [X-]Forwarded-For headers in HTTP requests when generating
          log messages. This lets people run dirservers (and caches) behind
          Apache but still know which IP addresses are causing warnings.
        - Fix minor integer overflow in calculating when we expect to use up
          our bandwidth allocation before hibernating.
        - Lower the minimum required number of file descriptors to 1000,
          so we can have some overhead for Valgrind on Linux, where the
          default ulimit -n is 1024.
        - Stop writing the "router.desc" file, ever. Nothing uses it anymore,
          and its existence is confusing some users.
    
      o Config option fixes:
        - Add a new config option ExitPolicyRejectPrivate which defaults
          to on. Now all exit policies will begin with rejecting private
          addresses, unless the server operator explicitly turns it off.
        - Bump the default bandwidthrate to 3 MB, and burst to 6 MB.
        - Add new ReachableORAddresses and ReachableDirAddresses options
          that understand address policies. FascistFirewall is now a synonym
          for "ReachableORAddresses *:443", "ReachableDirAddresses *:80".
        - Start calling it FooListenAddress rather than FooBindAddress,
          since few of our users know what it means to bind an address
          or port.
        - If the user gave Tor an odd number of command-line arguments,
          we were silently ignoring the last one. Now we complain and fail.
          This wins the oldest-bug prize -- this bug has been present since
          November 2002, as released in Tor 0.0.0.
        - If you write "HiddenServicePort 6667 127.0.0.1 6668" in your
          torrc rather than "HiddenServicePort 6667 127.0.0.1:6668",
          it would silently ignore the 6668.
        - If we get a linelist or linelist_s config option from the torrc,
          e.g. ExitPolicy, and it has no value, warn and skip rather than
          silently resetting it to its default.
        - Setconf was appending items to linelists, not clearing them.
        - Add MyFamily to torrc.sample in the server section, so operators
          will be more likely to learn that it exists.
        - Make ContactInfo mandatory for authoritative directory servers.
        - MaxConn has been obsolete for a while now. Document the ConnLimit
          config option, which is a *minimum* number of file descriptors
          that must be available else Tor refuses to start.
        - Get rid of IgnoreVersion undocumented config option, and make us
          only warn, never exit, when we're running an obsolete version.
        - Make MonthlyAccountingStart config option truly obsolete now.
        - Correct the man page entry on TrackHostExitsExpire.
        - Let directory authorities start even if they don't specify an
          Address config option.
        - Change "AllowUnverifiedNodes" to "AllowInvalidNodes", to
          reflect the updated flags in our v2 dir protocol.
    
      o Config option features:
        - Add a new config option FastFirstHopPK (on by default) so clients
          do a trivial crypto handshake for their first hop, since TLS has
          already taken care of confidentiality and authentication.
        - Let the user set ControlListenAddress in the torrc. This can be
          dangerous, but there are some cases (like a secured LAN) where it
          makes sense.
        - New config options to help controllers: FetchServerDescriptors
          and FetchHidServDescriptors for whether to fetch server
          info and hidserv info or let the controller do it, and
          PublishServerDescriptor and PublishHidServDescriptors.
        - Also let the controller set the __AllDirActionsPrivate config
          option if you want all directory fetches/publishes to happen via
          Tor (it assumes your controller bootstraps your circuits).
        - Add "HardwareAccel" config option: support for crypto hardware
          accelerators via OpenSSL. Off by default, until we find somebody
          smart who can test it for us. (It appears to produce seg faults
          in at least some cases.)
        - New config option "AuthDirRejectUnlisted" for directory authorities
          as a panic button: if we get flooded with unusable servers we can
          revert to only listing servers in the approved-routers file.
        - Directory authorities can now reject/invalidate by key and IP,
          with the config options "AuthDirInvalid" and "AuthDirReject", or
          by marking a fingerprint as "!reject" or "!invalid" (as its
          nickname) in the approved-routers file. This is useful since
          currently we automatically list servers as running and usable
          even if we know they're jerks.
        - Add a new config option TestSocks so people can see whether their
          applications are using socks4, socks4a, socks5-with-ip, or
          socks5-with-fqdn. This way they don't have to keep mucking
          with tcpdump and wondering if something got cached somewhere.
        - Add "private:*" as an alias in configuration for policies. Now
          you can simplify your exit policy rather than needing to list
          every single internal or nonroutable network space.
        - Accept "private:*" in routerdesc exit policies; not generated yet
          because older Tors do not understand it.
        - Add configuration option "V1AuthoritativeDirectory 1" which
          moria1, moria2, and tor26 have set.
        - Implement an option, VirtualAddrMask, to set which addresses
          get handed out in response to mapaddress requests. This works
          around a bug in tsocks where 127.0.0.0/8 is never socksified.
        - Add a new config option FetchUselessDescriptors, off by default,
          for when you plan to run "exitlist" on your client and you want
          to know about even the non-running descriptors.
        - SocksTimeout: How long do we let a socks connection wait
          unattached before we fail it?
        - CircuitBuildTimeout: Cull non-open circuits that were born
          at least this many seconds ago.
        - CircuitIdleTimeout: Cull open clean circuits that were born
          at least this many seconds ago.
        - New config option SafeSocks to reject all application connections
          using unsafe socks protocols. Defaults to off.
    
      o Improved and clearer log messages:
        - Reduce clutter in server logs. We're going to try to make
          them actually usable now. New config option ProtocolWarnings that
          lets you hear about how _other Tors_ are breaking the protocol. Off
          by default.
        - Divide log messages into logging domains. Once we put some sort
          of interface on this, it will let people looking at more verbose
          log levels specify the topics they want to hear more about.
        - Log server fingerprint on startup, so new server operators don't
          have to go hunting around their filesystem for it.
        - Provide dire warnings to any users who set DirServer manually;
          move it out of torrc.sample and into torrc.complete.
        - Make the log message less scary when all the dirservers are
          temporarily unreachable.
        - When tor_socketpair() fails in Windows, give a reasonable
          Windows-style errno back.
        - Improve tor_gettimeofday() granularity on windows.
        - We were printing the number of idle dns workers incorrectly when
          culling them.
        - Handle duplicate lines in approved-routers files without warning.
        - We were whining about using socks4 or socks5-with-local-lookup
          even when it's an IP address in the "virtual" range we designed
          exactly for this case.
        - Check for named servers when looking them up by nickname;
          warn when we're calling a non-named server by its nickname;
          don't warn twice about the same name.
        - Downgrade the dirserver log messages when whining about
          unreachability.
        - Correct "your server is reachable" log entries to indicate that
          it was self-testing that told us so.
        - If we're trying to be a Tor server and running Windows 95/98/ME
          as a server, explain that we'll likely crash.
        - Provide a more useful warn message when our onion queue gets full:
          the CPU is too slow or the exit policy is too liberal.
        - Don't warn when we receive a 503 from a dirserver/cache -- this
          will pave the way for them being able to refuse if they're busy.
        - When we fail to bind a listener, try to provide a more useful
          log message: e.g., "Is Tor already running?"
        - Only start testing reachability once we've established a
          circuit. This will make startup on dir authorities less noisy.
        - Don't try to upload hidden service descriptors until we have
          established a circuit.
        - Tor didn't warn when it failed to open a log file.
        - Warn when listening on a public address for socks. We suspect a
          lot of people are setting themselves up as open socks proxies,
          and they have no idea that jerks on the Internet are using them,
          since they simply proxy the traffic into the Tor network.
        - Give a useful message when people run Tor as the wrong user,
          rather than telling them to start chowning random directories.
        - Fix a harmless bug that was causing Tor servers to log
          "Got an end because of misc error, but we're not an AP. Closing."
        - Fix wrong log message when you add a "HiddenServiceNodes" config
          line without any HiddenServiceDir line (reported by Chris Thomas).
        - Directory authorities now stop whining so loudly about bad
          descriptors that they fetch from other dirservers. So when there's
          a log complaint, it's for sure from a freshly uploaded descriptor.
        - When logging via syslog, include the pid whenever we provide
          a log entry. Suggested by Todd Fries.
        - When we're shutting down and we do something like try to post a
          server descriptor or rendezvous descriptor, don't complain that
          we seem to be unreachable. Of course we are, we're shutting down.
        - Change log line for unreachability to explicitly suggest /etc/hosts
          as the culprit. Also make it clearer what IP address and ports we're
          testing for reachability.
        - Put quotes around user-supplied strings when logging so users are
          more likely to realize if they add bad characters (like quotes)
          to the torrc.
        - NT service patch from Matt Edman to improve error messages on Win32.
    
    
    Changes in version 0.1.0.17 - 2006-02-17
      o Crash bugfixes on 0.1.0.x:
        - When servers with a non-zero DirPort came out of hibernation,
          sometimes they would trigger an assert.
    
      o Other important bugfixes:
        - On platforms that don't have getrlimit (like Windows), we were
          artificially constraining ourselves to a max of 1024
          connections. Now just assume that we can handle as many as 15000
          connections. Hopefully this won't cause other problems.
    
      o Backported features:
        - When we're a server, a client asks for an old-style directory,
          and our write bucket is empty, don't give it to him. This way
          small servers can continue to serve the directory *sometimes*,
          without getting overloaded.
        - Whenever you get a 503 in response to a directory fetch, try
          once more. This will become important once servers start sending
          503's whenever they feel busy.
        - Fetch a new directory every 120 minutes, not every 40 minutes.
          Now that we have hundreds of thousands of users running the old
          directory algorithm, it's starting to hurt a lot.
        - Bump up the period for forcing a hidden service descriptor upload
          from 20 minutes to 1 hour.
    
    
    Changes in version 0.1.0.16 - 2006-01-02
      o Crash bugfixes on 0.1.0.x:
        - On Windows, build with a libevent patch from "I-M Weasel" to avoid
          corrupting the heap, losing FDs, or crashing when we need to resize
          the fd_sets. (This affects the Win32 binaries, not Tor's sources.)
        - It turns out sparc64 platforms crash on unaligned memory access
          too -- so detect and avoid this.
        - Handle truncated compressed data correctly (by detecting it and
          giving an error).
        - Fix possible-but-unlikely free(NULL) in control.c.
        - When we were closing connections, there was a rare case that
          stomped on memory, triggering seg faults and asserts.
        - Avoid potential infinite recursion when building a descriptor. (We
          don't know that it ever happened, but better to fix it anyway.)
        - We were neglecting to unlink marked circuits from soon-to-close OR
          connections, which caused some rare scribbling on freed memory.
        - Fix a memory stomping race bug when closing the joining point of two
          rendezvous circuits.
        - Fix an assert in time parsing found by Steven Murdoch.
    
      o Other bugfixes on 0.1.0.x:
        - When we're doing reachability testing, provide more useful log
          messages so the operator knows what to expect.
        - Do not check whether DirPort is reachable when we are suppressing
          advertising it because of hibernation.
        - When building with -static or on Solaris, we sometimes needed -ldl.
        - One of the dirservers (tor26) changed its IP address.
        - When we're deciding whether a stream has enough circuits around
          that can handle it, count the freshly dirty ones and not the ones
          that are so dirty they won't be able to handle it.
        - When we're expiring old circuits, we had a logic error that caused
          us to close new rendezvous circuits rather than old ones.
        - Give a more helpful log message when you try to change ORPort via
          the controller: you should upgrade Tor if you want that to work.
        - We were failing to parse Tor versions that start with "Tor ".
        - Tolerate faulty streams better: when a stream fails for reason
          exitpolicy, stop assuming that the router is lying about his exit
          policy. When a stream fails for reason misc, allow it to retry just
          as if it was resolvefailed. When a stream has failed three times,
          reset its failure count so we can try again and get all three tries.
    
    
    Changes in version 0.1.0.15 - 2005-09-23
      o Bugfixes on 0.1.0.x:
        - Reject ports 465 and 587 (spam targets) in default exit policy.
        - Don't crash when we don't have any spare file descriptors and we
          try to spawn a dns or cpu worker.
        - Get rid of IgnoreVersion undocumented config option, and make us
          only warn, never exit, when we're running an obsolete version.
        - Don't try to print a null string when your server finds itself to
          be unreachable and the Address config option is empty.
        - Make the numbers in read-history and write-history into uint64s,
          so they don't overflow and publish negatives in the descriptor.
        - Fix a minor memory leak in smartlist_string_remove().
        - We were only allowing ourselves to upload a server descriptor at
          most every 20 minutes, even if it changed earlier than that.
        - Clean up log entries that pointed to old URLs.
    
    
    Changes in version 0.1.0.14 - 2005-08-08
      o Bugfixes on 0.1.0.x:
          - Fix the other half of the bug with crypto handshakes
            (CVE-2005-2643).
          - Fix an assert trigger if you send a 'signal term' via the
            controller when it's listening for 'event info' messages.
    
    
    Changes in version 0.1.0.13 - 2005-08-04
      o Bugfixes on 0.1.0.x:
        - Fix a critical bug in the security of our crypto handshakes.
        - Fix a size_t underflow in smartlist_join_strings2() that made
          it do bad things when you hand it an empty smartlist.
        - Fix Windows installer to ship Tor license (thanks to Aphex for
          pointing out this oversight) and put a link to the doc directory
          in the start menu.
        - Explicitly set no-unaligned-access for sparc: it turns out the
          new gcc's let you compile broken code, but that doesn't make it
          not-broken.
    
    
    Changes in version 0.1.0.12 - 2005-07-18
      o New directory servers:
          - tor26 has changed IP address.
    
      o Bugfixes on 0.1.0.x:
        - Fix a possible double-free in tor_gzip_uncompress().
        - When --disable-threads is set, do not search for or link against
          pthreads libraries.
        - Don't trigger an assert if an authoritative directory server
          claims its dirport is 0.
        - Fix bug with removing Tor as an NT service: some people were
          getting "The service did not return an error." Thanks to Matt
          Edman for the fix.
    
    
    Changes in version 0.1.0.11 - 2005-06-30
      o Bugfixes on 0.1.0.x:
        - Fix major security bug: servers were disregarding their
          exit policies if clients behaved unexpectedly.
        - Make OS X init script check for missing argument, so we don't
          confuse users who invoke it incorrectly.
        - Fix a seg fault in "tor --hash-password foo".
        - The MAPADDRESS control command was broken.
    
    
    Changes in version 0.1.0.10 - 2005-06-14
      o Fixes on Win32:
        - Make NT services work and start on startup on Win32 (based on
          patch by Matt Edman). See the FAQ entry for details.
        - Make 'platform' string in descriptor more accurate for Win32
          servers, so it's not just "unknown platform".
        - REUSEADDR on normal platforms means you can rebind to the port
          right after somebody else has let it go. But REUSEADDR on Win32
          means you can bind to the port _even when somebody else already
          has it bound_! So, don't do that on Win32.
        - Clean up the log messages when starting on Win32 with no config
          file.
        - Allow seeding the RNG on Win32 even when you're not running as
          Administrator. If seeding the RNG on Win32 fails, quit.
    
      o Assert / crash bugs:
        - Refuse relay cells that claim to have a length larger than the
          maximum allowed. This prevents a potential attack that could read
          arbitrary memory (e.g. keys) from an exit server's process
          (CVE-2005-2050).
        - If unofficial Tor clients connect and send weird TLS certs, our
          Tor server triggers an assert. Stop asserting, and start handling
          TLS errors better in other situations too.
        - Fix a race condition that can trigger an assert when we have a
          pending create cell and an OR connection attempt fails.
    
      o Resource leaks:
        - Use pthreads for worker processes rather than forking. This was
          forced because when we forked, we ended up wasting a lot of
          duplicate ram over time.
          - Also switch to foo_r versions of some library calls to allow
            reentry and threadsafeness.
          - Implement --disable-threads configure option. Disable threads on
            netbsd and openbsd by default, because they have no reentrant
            resolver functions (!), and on solaris since it has other
            threading issues.
        - Fix possible bug on threading platforms (e.g. win32) which was
          leaking a file descriptor whenever a cpuworker or dnsworker died.
        - Fix a minor memory leak when somebody establishes an introduction
          point at your Tor server.
        - Fix possible memory leak in tor_lookup_hostname(). (Thanks to
          Adam Langley.)
        - Add ./configure --with-dmalloc option, to track memory leaks.
        - And try to free all memory on closing, so we can detect what
          we're leaking.
    
      o Protocol correctness:
        - When we've connected to an OR and handshaked but didn't like
          the result, we were closing the conn without sending destroy
          cells back for pending circuits. Now send those destroys.
        - Start sending 'truncated' cells back rather than destroy cells
          if the circuit closes in front of you. This means we won't have
          to abandon partially built circuits.
        - Handle changed router status correctly when dirserver reloads
          fingerprint file. We used to be dropping all unverified descriptors
          right then. The bug was hidden because we would immediately
          fetch a directory from another dirserver, which would include the
          descriptors we just dropped.
        - Revise tor-spec to add more/better stream end reasons.
        - Revise all calls to connection_edge_end to avoid sending 'misc',
          and to take errno into account where possible.
        - Client now retries when streams end early for 'hibernating' or
          'resource limit' reasons, rather than failing them.
        - Try to be more zealous about calling connection_edge_end when
          things go bad with edge conns in connection.c.
    
      o Robustness improvements:
        - Better handling for heterogeneous / unreliable nodes:
          - Annotate circuits with whether they aim to contain high uptime
            nodes and/or high capacity nodes. When building circuits, choose
            appropriate nodes.
          - This means that every single node in an intro rend circuit,
            not just the last one, will have a minimum uptime.
          - New config option LongLivedPorts to indicate application streams
            that will want high uptime circuits.
          - Servers reset uptime when a dir fetch entirely fails. This
            hopefully reflects stability of the server's network connectivity.
          - If somebody starts his tor server in Jan 2004 and then fixes his
            clock, don't make his published uptime be a year.
          - Reset published uptime when we wake up from hibernation.
        - Introduce a notion of 'internal' circs, which are chosen without
          regard to the exit policy of the last hop. Intro and rendezvous
          circs must be internal circs, to avoid leaking information. Resolve
          and connect streams can use internal circs if they want.
        - New circuit pooling algorithm: keep track of what destination ports
          we've used recently (start out assuming we'll want to use 80), and
          make sure to have enough circs around to satisfy these ports. Also
          make sure to have 2 internal circs around if we've required internal
          circs lately (and with high uptime if we've seen that lately too).
        - Turn addr_policy_compare from a tristate to a quadstate; this should
          help address our "Ah, you allow 1.2.3.4:80. You are a good choice
          for google.com" problem.
        - When a client asks us for a dir mirror and we don't have one,
          launch an attempt to get a fresh one.
        - First cut at support for "create-fast" cells. Clients can use
          these when extending to their first hop, since the TLS already
          provides forward secrecy and authentication. Not enabled on
          clients yet.
    
      o Reachability testing.
        - Your Tor server will automatically try to see if its ORPort and
          DirPort are reachable from the outside, and it won't upload its
          descriptor until it decides at least ORPort is reachable (when
          DirPort is not yet found reachable, publish it as zero).
        - When building testing circs for ORPort testing, use only
          high-bandwidth nodes, so fewer circuits fail.
        - Notice when our IP changes, and reset stats/uptime/reachability.
        - Authdirservers don't do ORPort reachability detection, since
          they're in clique mode, so it will be rare to find a server not
          already connected to them.
        - Authdirservers now automatically approve nodes running 0.1.0.2-rc
          or later.
    
      o Dirserver fixes:
        - Now we allow two unverified servers with the same nickname
          but different keys. But if a nickname is verified, only that
          nickname+key are allowed.
        - If you're an authdirserver connecting to an address:port,
          and it's not the OR you were expecting, forget about that
          descriptor. If he *was* the one you were expecting, then forget
          about all other descriptors for that address:port.
        - Allow servers to publish descriptors from 12 hours in the future.
          Corollary: only whine about clock skew from the dirserver if
          he's a trusted dirserver (since now even verified servers could
          have quite wrong clocks).
        - Require servers that use the default dirservers to have public IP
          addresses. We have too many servers that are configured with private
          IPs and their admins never notice the log entries complaining that
          their descriptors are being rejected.
    
      o Efficiency improvements:
        - Use libevent. Now we can use faster async cores (like epoll, kpoll,
          and /dev/poll), and hopefully work better on Windows too.
          - Apple's OS X 10.4.0 ships with a broken kqueue API, and using
            kqueue on 10.3.9 causes kernel panics. Don't use kqueue on OS X.
          - Find libevent even if it's hiding in /usr/local/ and your
            CFLAGS and LDFLAGS don't tell you to look there.
          - Be able to link with libevent as a shared library (the default
            after 1.0d), even if it's hiding in /usr/local/lib and even
            if you haven't added /usr/local/lib to your /etc/ld.so.conf,
            assuming you're running gcc. Otherwise fail and give a useful
            error message.
        - Switch to a new buffer management algorithm, which tries to avoid
          reallocing and copying quite as much. In first tests it looks like
          it uses *more* memory on average, but less cpu.
        - Switch our internal buffers implementation to use a ring buffer,
          to hopefully improve performance for fast servers a lot.
        - Reenable the part of the code that tries to flush as soon as an
          OR outbuf has a full TLS record available. Perhaps this will make
          OR outbufs not grow as huge except in rare cases, thus saving lots
          of CPU time plus memory.
        - Improve performance for dirservers: stop re-parsing the whole
          directory every time you regenerate it.
        - Keep a big splay tree of (circid,orconn)->circuit mappings to make
          it much faster to look up a circuit for each relay cell.
        - Remove most calls to assert_all_pending_dns_resolves_ok(),
          since they're eating our cpu on exit nodes.
        - Stop wasting time doing a case insensitive comparison for every
          dns name every time we do any lookup. Canonicalize the names to
          lowercase when you first see them.
    
      o Hidden services:
        - Handle unavailable hidden services better. Handle slow or busy
          hidden services better.
        - Cannibalize GENERAL circs to be C_REND, C_INTRO, S_INTRO, and S_REND
          circ as necessary, if there are any completed ones lying around
          when we try to launch one.
        - Make hidden services try to establish a rendezvous for 30 seconds
          after fetching the descriptor, rather than for n (where n=3)
          attempts to build a circuit.
        - Adjust maximum skew and age for rendezvous descriptors: let skew
          be 48 hours rather than 90 minutes.
        - Reject malformed .onion addresses rather then passing them on as
          normal web requests.
    
      o Controller:
        - More Tor controller support. See
          http://tor.eff.org/doc/control-spec.txt for all the new features,
          including signals to emulate unix signals from any platform;
          redirectstream; extendcircuit; mapaddress; getinfo; postdescriptor;
          closestream; closecircuit; etc.
        - Encode hashed controller passwords in hex instead of base64,
          to make it easier to write controllers.
        - Revise control spec and implementation to allow all log messages to
          be sent to controller with their severities intact (suggested by
          Matt Edman). Disable debug-level logs while delivering a debug-level
          log to the controller, to prevent loop. Update TorControl to handle
          new log event types.
    
      o New config options/defaults:
        - Begin scrubbing sensitive strings from logs by default. Turn off
          the config option SafeLogging if you need to do debugging.
        - New exit policy: accept most low-numbered ports, rather than
          rejecting most low-numbered ports.
        - Put a note in the torrc about abuse potential with the default
          exit policy.
        - Add support for CONNECTing through https proxies, with "HttpsProxy"
          config option.
        - Add HttpProxyAuthenticator and HttpsProxyAuthenticator support
          based on patch from Adam Langley (basic auth only).
        - Bump the default BandwidthRate from 1 MB to 2 MB, to accommodate
          the fast servers that have been joining lately. (Clients are now
          willing to load balance over up to 2 MB of advertised bandwidth
          capacity too.)
        - New config option MaxAdvertisedBandwidth which lets you advertise
          a low bandwidthrate (to not attract as many circuits) while still
          allowing a higher bandwidthrate in reality.
        - Require BandwidthRate to be at least 20kB/s for servers.
        - Add a NoPublish config option, so you can be a server (e.g. for
          testing running Tor servers in other Tor networks) without
          publishing your descriptor to the primary dirservers.
        - Add a new AddressMap config directive to rewrite incoming socks
          addresses. This lets you, for example, declare an implicit
          required exit node for certain sites.
        - Add a new TrackHostExits config directive to trigger addressmaps
          for certain incoming socks addresses -- for sites that break when
          your exit keeps changing (based on patch from Mike Perry).
        - Split NewCircuitPeriod option into NewCircuitPeriod (30 secs),
          which describes how often we retry making new circuits if current
          ones are dirty, and MaxCircuitDirtiness (10 mins), which describes
          how long we're willing to make use of an already-dirty circuit.
        - Change compiled-in SHUTDOWN_WAIT_LENGTH from a fixed 30 secs to
          a config option "ShutdownWaitLength" (when using kill -INT on
          servers).
        - Fix an edge case in parsing config options: if they say "--"
          on the commandline, it's not a config option (thanks weasel).
        - New config option DirAllowPrivateAddresses for authdirservers.
          Now by default they refuse router descriptors that have non-IP or
          private-IP addresses.
        - Change DirFetchPeriod/StatusFetchPeriod to have a special "Be
          smart" default value: low for servers and high for clients.
        - Some people were putting "Address  " in their torrc, and they had
          a buggy resolver that resolved " " to 0.0.0.0. Oops.
        - If DataDir is ~/.tor, and that expands to /.tor, then default to
          LOCALSTATEDIR/tor instead.
        - Implement --verify-config command-line option to check if your torrc
          is valid without actually launching Tor.
    
      o Logging improvements:
        - When dirservers refuse a server descriptor, we now log its
          contactinfo, platform, and the poster's IP address.
        - Only warn once per nickname from add_nickname_list_to_smartlist()
          per failure, so an entrynode or exitnode choice that's down won't
          yell so much.
        - When we're connecting to an OR and he's got a different nickname/key
          than we were expecting, only complain loudly if we're an OP or a
          dirserver. Complaining loudly to the OR admins just confuses them.
        - Whine at you if you're a server and you don't set your contactinfo.
        - Warn when exit policy implicitly allows local addresses.
        - Give a better warning when some other server advertises an
          ORPort that is actually an apache running ssl.
        - If we get an incredibly skewed timestamp from a dirserver mirror
          that isn't a verified OR, don't warn -- it's probably him that's
          wrong.
        - When a dirserver causes you to give a warn, mention which dirserver
          it was.
        - Initialize libevent later in the startup process, so the logs are
          already established by the time we start logging libevent warns.
        - Use correct errno on win32 if libevent fails.
        - Check and warn about known-bad/slow libevent versions.
        - Stop warning about sigpipes in the logs. We're going to
          pretend that getting these occasionally is normal and fine.
    
      o New contrib scripts:
        - New experimental script tor/contrib/exitlist: a simple python
          script to parse directories and find Tor nodes that exit to listed
          addresses/ports.
        - New experimental script tor/contrib/ExerciseServer.py (needs more
          work) that uses the controller interface to build circuits and
          fetch pages over them. This will help us bootstrap servers that
          have lots of capacity but haven't noticed it yet.
        - New experimental script tor/contrib/PathDemo.py (needs more work)
          that uses the controller interface to let you choose whole paths
          via addresses like
          "<hostname>.<path,separated by dots>.<length of path>.path"
        - New contributed script "privoxy-tor-toggle" to toggle whether
          Privoxy uses Tor. Seems to be configured for Debian by default.
        - Have torctl.in/tor.sh.in check for location of su binary (needed
          on FreeBSD)
    
      o Misc bugfixes:
        - chdir() to your datadirectory at the *end* of the daemonize process,
          not the beginning. This was a problem because the first time you
          run tor, if your datadir isn't there, and you have runasdaemon set
          to 1, it will try to chdir to it before it tries to create it. Oops.
        - Fix several double-mark-for-close bugs, e.g. where we were finding
          a conn for a cell even if that conn is already marked for close.
        - Stop most cases of hanging up on a socks connection without sending
          the socks reject.
        - Fix a bug in the RPM package: set home directory for _tor to
          something more reasonable when first installing.
        - Stop putting nodename in the Platform string in server descriptors.
          It doesn't actually help, and it is confusing/upsetting some people.
        - When using preferred entry or exit nodes, ignore whether the
          circuit wants uptime or capacity. They asked for the nodes, they
          get the nodes.
        - Tie MAX_DIR_SIZE to MAX_BUF_SIZE, so now directory sizes won't get
          artificially capped at 500kB.
        - Cache local dns resolves correctly even when they're .exit
          addresses.
        - If we're hibernating and we get a SIGINT, exit immediately.
        - tor-resolve requests were ignoring .exit if there was a working circuit
          they could use instead.
        - Pay more attention to the ClientOnly config option.
        - Resolve OS X installer bugs: stop claiming to be 0.0.9.2 in certain
          installer screens; and don't put stuff into StartupItems unless
          the user asks you to.
    
      o Misc features:
        - Rewrite address "serifos.exit" to "externalIP.serifos.exit"
          rather than just rejecting it.
        - If our clock jumps forward by 100 seconds or more, assume something
          has gone wrong with our network and abandon all not-yet-used circs.
        - When an application is using socks5, give him the whole variety of
          potential socks5 responses (connect refused, host unreachable, etc),
          rather than just "success" or "failure".
        - A more sane version numbering system. See
          http://tor.eff.org/cvs/tor/doc/version-spec.txt for details.
        - Change version parsing logic: a version is "obsolete" if it is not
          recommended and (1) there is a newer recommended version in the
          same series, or (2) there are no recommended versions in the same
          series, but there are some recommended versions in a newer series.
          A version is "new" if it is newer than any recommended version in
          the same series.
        - Report HTTP reasons to client when getting a response from directory
          servers -- so you can actually know what went wrong.
        - Reject odd-looking addresses at the client (e.g. addresses that
          contain a colon), rather than having the server drop them because
          they're malformed.
        - Stop publishing socksport in the directory, since it's not
          actually meant to be public. For compatibility, publish a 0 there
          for now.
        - Since we ship our own Privoxy on OS X, tweak it so it doesn't write
          cookies to disk and doesn't log each web request to disk. (Thanks
          to Brett Carrington for pointing this out.)
        - Add OSX uninstall instructions. An actual uninstall script will
          come later.
        - Add "opt hibernating 1" to server descriptor to make it clearer
          whether the server is hibernating.
    
    
    Changes in version 0.0.9.10 - 2005-06-16
      o Bugfixes on 0.0.9.x (backported from 0.1.0.10):
        - Refuse relay cells that claim to have a length larger than the
          maximum allowed. This prevents a potential attack that could read
          arbitrary memory (e.g. keys) from an exit server's process
          (CVE-2005-2050).
    
    
    Changes in version 0.0.9.9 - 2005-04-23
      o Bugfixes on 0.0.9.x:
        - If unofficial Tor clients connect and send weird TLS certs, our
          Tor server triggers an assert. This release contains a minimal
          backport from the broader fix that we put into 0.1.0.4-rc.
    
    
    Changes in version 0.0.9.8 - 2005-04-07
      o Bugfixes on 0.0.9.x:
        - We have a bug that I haven't found yet. Sometimes, very rarely,
          cpuworkers get stuck in the 'busy' state, even though the cpuworker
          thinks of itself as idle. This meant that no new circuits ever got
          established. Here's a workaround to kill any cpuworker that's been
          busy for more than 100 seconds.
    
    
    Changes in version 0.0.9.7 - 2005-04-01
      o Bugfixes on 0.0.9.x:
        - Fix another race crash bug (thanks to Glenn Fink for reporting).
        - Compare identity to identity, not to nickname, when extending to
          a router not already in the directory. This was preventing us from
          extending to unknown routers. Oops.
        - Make sure to create OS X Tor user in <500 range, so we aren't
          creating actual system users.
        - Note where connection-that-hasn't-sent-end was marked, and fix
          a few really loud instances of this harmless bug (it's fixed more
          in 0.1.0.x).
    
    
    Changes in version 0.0.9.6 - 2005-03-24
      o Bugfixes on 0.0.9.x (crashes and asserts):
        - Add new end stream reasons to maintenance branch. Fix bug where
          reason (8) could trigger an assert.  Prevent bug from recurring.
        - Apparently win32 stat wants paths to not end with a slash.
        - Fix assert triggers in assert_cpath_layer_ok(), where we were
          blowing away the circuit that conn->cpath_layer points to, then
          checking to see if the circ is well-formed. Backport check to make
          sure we dont use the cpath on a closed connection.
        - Prevent circuit_resume_edge_reading_helper() from trying to package
          inbufs for marked-for-close streams.
        - Don't crash on hup if your options->address has become unresolvable.
        - Some systems (like OS X) sometimes accept() a connection and tell
          you the remote host is 0.0.0.0:0. If this happens, due to some
          other mis-features, we get confused; so refuse the conn for now.
    
      o Bugfixes on 0.0.9.x (other):
        - Fix harmless but scary "Unrecognized content encoding" warn message.
        - Add new stream error reason: TORPROTOCOL reason means "you are not
          speaking a version of Tor I understand; say bye-bye to your stream."
        - Be willing to cache directories from up to ROUTER_MAX_AGE seconds
          into the future, now that we are more tolerant of skew. This
          resolves a bug where a Tor server would refuse to cache a directory
          because all the directories it gets are too far in the future;
          yet the Tor server never logs any complaints about clock skew.
        - Mac packaging magic: make man pages useable, and do not overwrite
          existing torrc files.
        - Make OS X log happily to /var/log/tor/tor.log
    
    
    Changes in version 0.0.9.5 - 2005-02-22
      o Bugfixes on 0.0.9.x:
        - Fix an assert race at exit nodes when resolve requests fail.
        - Stop picking unverified dir mirrors--it only leads to misery.
        - Patch from Matt Edman to make NT services work better. Service
          support is still not compiled into the executable by default.
        - Patch from Dmitri Bely so the Tor service runs better under
          the win32 SYSTEM account.
        - Make tor-resolve actually work (?) on Win32.
        - Fix a sign bug when getrlimit claims to have 4+ billion
          file descriptors available.
        - Stop refusing to start when bandwidthburst == bandwidthrate.
        - When create cells have been on the onion queue more than five
          seconds, just send back a destroy and take them off the list.
    
    
    Changes in version 0.0.9.4 - 2005-02-03
      o Bugfixes on 0.0.9:
        - Fix an assert bug that took down most of our servers: when
          a server claims to have 1 GB of bandwidthburst, don't
          freak out.
        - Don't crash as badly if we have spawned the max allowed number
          of dnsworkers, or we're out of file descriptors.
        - Block more file-sharing ports in the default exit policy.
        - MaxConn is now automatically set to the hard limit of max
          file descriptors we're allowed (ulimit -n), minus a few for
          logs, etc.
        - Give a clearer message when servers need to raise their
          ulimit -n when they start running out of file descriptors.
        - SGI Compatibility patches from Jan Schaumann.
        - Tolerate a corrupt cached directory better.
        - When a dirserver hasn't approved your server, list which one.
        - Go into soft hibernation after 95% of the bandwidth is used,
          not 99%. This is especially important for daily hibernators who
          have a small accounting max. Hopefully it will result in fewer
          cut connections when the hard hibernation starts.
        - Load-balance better when using servers that claim more than
          800kB/s of capacity.
        - Make NT services work (experimental, only used if compiled in).
    
    
    Changes in version 0.0.9.3 - 2005-01-21
      o Bugfixes on 0.0.9:
        - Backport the cpu use fixes from main branch, so busy servers won't
          need as much processor time.
        - Work better when we go offline and then come back, or when we
          run Tor at boot before the network is up. We do this by
          optimistically trying to fetch a new directory whenever an
          application request comes in and we think we're offline -- the
          human is hopefully a good measure of when the network is back.
        - Backport some minimal hidserv bugfixes: keep rend circuits open as
          long as you keep using them; actually publish hidserv descriptors
          shortly after they change, rather than waiting 20-40 minutes.
        - Enable Mac startup script by default.
        - Fix duplicate dns_cancel_pending_resolve reported by Giorgos Pallas.
        - When you update AllowUnverifiedNodes or FirewallPorts via the
          controller's setconf feature, we were always appending, never
          resetting.
        - When you update HiddenServiceDir via setconf, it was screwing up
          the order of reading the lines, making it fail.
        - Do not rewrite a cached directory back to the cache; otherwise we
          will think it is recent and not fetch a newer one on startup.
        - Workaround for webservers that lie about Content-Encoding: Tor
          now tries to autodetect compressed directories and compression
          itself. This lets us Proxypass dir fetches through apache.
    
    
    Changes in version 0.0.9.2 - 2005-01-04
      o Bugfixes on 0.0.9 (crashes and asserts):
        - Fix an assert on startup when the disk is full and you're logging
          to a file.
        - If you do socks4 with an IP of 0.0.0.x but *don't* provide a socks4a
          style address, then we'd crash.
        - Fix an assert trigger when the running-routers string we get from
          a dirserver is broken.
        - Make worker threads start and run on win32. Now win32 servers
          may work better.
        - Bandaid (not actually fix, but now it doesn't crash) an assert
          where the dns worker dies mysteriously and the main Tor process
          doesn't remember anything about the address it was resolving.
    
      o Bugfixes on 0.0.9 (Win32):
        - Workaround for brain-damaged __FILE__ handling on MSVC: keep Nick's
          name out of the warning/assert messages.
        - Fix a superficial "unhandled error on read" bug on win32.
        - The win32 installer no longer requires a click-through for our
          license, since our Free Software license grants rights but does not
          take any away.
        - Win32: When connecting to a dirserver fails, try another one
          immediately. (This was already working for non-win32 Tors.)
        - Stop trying to parse $HOME on win32 when hunting for default
          DataDirectory.
        - Make tor-resolve.c work on win32 by calling network_init().
    
      o Bugfixes on 0.0.9 (other):
        - Make 0.0.9.x build on Solaris again.
        - Due to a fencepost error, we were blowing away the \n when reporting
          confvalue items in the controller. So asking for multiple config
          values at once couldn't work.
        - When listing circuits that are pending on an opening OR connection,
          if we're an OR we were listing circuits that *end* at us as
          being pending on every listener, dns/cpu worker, etc. Stop that.
        - Dirservers were failing to create 'running-routers' or 'directory'
          strings if we had more than some threshold of routers. Fix them so
          they can handle any number of routers.
        - Fix a superficial "Duplicate mark for close" bug.
        - Stop checking for clock skew for OR connections, even for servers.
        - Fix a fencepost error that was chopping off the last letter of any
          nickname that is the maximum allowed nickname length.
        - Update URLs in log messages so they point to the new website.
        - Fix a potential problem in mangling server private keys while
          writing to disk (not triggered yet, as far as we know).
        - Include the licenses for other free software we include in Tor,
          now that we're shipping binary distributions more regularly.
    
    
    Changes in version 0.0.9.1 - 2004-12-15
      o Bugfixes on 0.0.9:
        - Make hibernation actually work.
        - Make HashedControlPassword config option work.
        - When we're reporting event circuit status to a controller,
          don't use the stream status code.
    
    
    Changes in version 0.0.9 - 2004-12-12
      o Bugfixes on 0.0.8.1 (Crashes and asserts):
        - Catch and ignore SIGXFSZ signals when log files exceed 2GB; our
          write() call will fail and we handle it there.
        - When we run out of disk space, or other log writing error, don't
          crash. Just stop logging to that log and continue.
        - Fix isspace() and friends so they still make Solaris happy
          but also so they don't trigger asserts on win32.
        - Fix assert failure on malformed socks4a requests.
        - Fix an assert bug where a hidden service provider would fail if
          the first hop of his rendezvous circuit was down.
        - Better handling of size_t vs int, so we're more robust on 64
          bit platforms.
    
      o Bugfixes on 0.0.8.1 (Win32):
        - Make windows sockets actually non-blocking (oops), and handle
          win32 socket errors better.
        - Fix parse_iso_time on platforms without strptime (eg win32).
        - win32: when being multithreaded, leave parent fdarray open.
        - Better handling of winsock includes on non-MSV win32 compilers.
        - Change our file IO stuff (especially wrt OpenSSL) so win32 is
          happier.
        - Make unit tests work on win32.
    
      o Bugfixes on 0.0.8.1 (Path selection and streams):
        - Calculate timeout for waiting for a connected cell from the time
          we sent the begin cell, not from the time the stream started. If
          it took a long time to establish the circuit, we would time out
          right after sending the begin cell.
        - Fix router_compare_addr_to_addr_policy: it was not treating a port
          of * as always matching, so we were picking reject *:* nodes as
          exit nodes too. Oops.
        - When read() failed on a stream, we would close it without sending
          back an end. So 'connection refused' would simply be ignored and
          the user would get no response.
        - Stop a sigpipe: when an 'end' cell races with eof from the app,
          we shouldn't hold-open-until-flush if the eof arrived first.
        - Let resolve conns retry/expire also, rather than sticking around
          forever.
        - Fix more dns related bugs: send back resolve_failed and end cells
          more reliably when the resolve fails, rather than closing the
          circuit and then trying to send the cell. Also attach dummy resolve
          connections to a circuit *before* calling dns_resolve(), to fix
          a bug where cached answers would never be sent in RESOLVED cells.
    
      o Bugfixes on 0.0.8.1 (Circuits):
        - Finally fix a bug that's been plaguing us for a year:
          With high load, circuit package window was reaching 0. Whenever
          we got a circuit-level sendme, we were reading a lot on each
          socket, but only writing out a bit. So we would eventually reach
          eof. This would be noticed and acted on even when there were still
          bytes sitting in the inbuf.
        - Use identity comparison, not nickname comparison, to choose which
          half of circuit-ID-space each side gets to use. This is needed
          because sometimes we think of a router as a nickname, and sometimes
          as a hex ID, and we can't predict what the other side will do.
    
      o Bugfixes on 0.0.8.1 (Other):
        - Fix a whole slew of memory leaks.
        - Disallow NDEBUG. We don't ever want anybody to turn off debug.
        - If we are using select, make sure we stay within FD_SETSIZE.
        - When poll() is interrupted, we shouldn't believe the revents values.
        - Add a FAST_SMARTLIST define to optionally inline smartlist_get
          and smartlist_len, which are two major profiling offenders.
        - If do_hup fails, actually notice.
        - Flush the log file descriptor after we print "Tor opening log file",
          so we don't see those messages days later.
        - Hidden service operators now correctly handle version 1 style
          INTRODUCE1 cells (nobody generates them still, so not a critical
          bug).
        - Handle more errnos from accept() without closing the listener.
          Some OpenBSD machines were closing their listeners because
          they ran out of file descriptors.
        - Some people had wrapped their tor client/server in a script
          that would restart it whenever it died. This did not play well
          with our "shut down if your version is obsolete" code. Now people
          don't fetch a new directory if their local cached version is
          recent enough.
        - Make our autogen.sh work on ksh as well as bash.
        - Better torrc example lines for dirbindaddress and orbindaddress.
        - Improved bounds checking on parsed ints (e.g. config options and
          the ones we find in directories.)
        - Stop using separate defaults for no-config-file and
          empty-config-file. Now you have to explicitly turn off SocksPort,
          if you don't want it open.
        - We were starting to daemonize before we opened our logs, so if
          there were any problems opening logs, we would complain to stderr,
          which wouldn't work, and then mysteriously exit.
        - If a verified OR connects to us before he's uploaded his descriptor,
          or we verify him and hup but he still has the original TLS
          connection, then conn->nickname is still set like he's unverified.
    
      o Code security improvements, inspired by Ilja:
        - tor_snprintf wrapper over snprintf with consistent (though not C99)
          overflow behavior.
        - Replace sprintf with tor_snprintf. (I think they were all safe, but
          hey.)
        - Replace strcpy/strncpy with strlcpy in more places.
        - Avoid strcat; use tor_snprintf or strlcat instead.
    
      o Features (circuits and streams):
        - New circuit building strategy: keep a list of ports that we've
          used in the past 6 hours, and always try to have 2 circuits open
          or on the way that will handle each such port. Seed us with port
          80 so web users won't complain that Tor is "slow to start up".
        - Make kill -USR1 dump more useful stats about circuits.
        - When warning about retrying or giving up, print the address, so
          the user knows which one it's talking about.
        - If you haven't used a clean circuit in an hour, throw it away,
          just to be on the safe side. (This means after 6 hours a totally
          unused Tor client will have no circuits open.)
        - Support "foo.nickname.exit" addresses, to let Alice request the
          address "foo" as viewed by exit node "nickname". Based on a patch
          from Geoff Goodell.
        - If your requested entry or exit node has advertised bandwidth 0,
          pick it anyway.
        - Be more greedy about filling up relay cells -- we try reading again
          once we've processed the stuff we read, in case enough has arrived
          to fill the last cell completely.
        - Refuse application socks connections to port 0.
        - Use only 0.0.9pre1 and later servers for resolve cells.
    
      o Features (bandwidth):
        - Hibernation: New config option "AccountingMax" lets you
          set how many bytes per month (in each direction) you want to
          allow your server to consume. Rather than spreading those
          bytes out evenly over the month, we instead hibernate for some
          of the month and pop up at a deterministic time, work until
          the bytes are consumed, then hibernate again. Config option
          "MonthlyAccountingStart" lets you specify which day of the month
          your billing cycle starts on.
        - Implement weekly/monthly/daily accounting: now you specify your
          hibernation properties by
          AccountingMax N bytes|KB|MB|GB|TB
          AccountingStart day|week|month [day] HH:MM
            Defaults to "month 1 0:00".
        - Let bandwidth and interval config options be specified as 5 bytes,
          kb, kilobytes, etc; and as seconds, minutes, hours, days, weeks.
    
      o Features (directories):
        - New "router-status" line in directory, to better bind each verified
          nickname to its identity key.
        - Clients can ask dirservers for /dir.z to get a compressed version
          of the directory. Only works for servers running 0.0.9, of course.
        - Make clients cache directories and use them to seed their router
          lists at startup. This means clients have a datadir again.
        - Respond to content-encoding headers by trying to uncompress as
          appropriate.
        - Clients and servers now fetch running-routers; cache
          running-routers; compress running-routers; serve compressed
          running-routers.z
        - Make moria2 advertise a dirport of 80, so people behind firewalls
          will be able to get a directory.
        - Http proxy support
          - Dirservers translate requests for http://%s:%d/x to /x
          - You can specify "HttpProxy %s[:%d]" and all dir fetches will
            be routed through this host.
          - Clients ask for /tor/x rather than /x for new enough dirservers.
            This way we can one day coexist peacefully with apache.
          - Clients specify a "Host: %s%d" http header, to be compatible
            with more proxies, and so running squid on an exit node can work.
        - Protect dirservers from overzealous descriptor uploading -- wait
          10 seconds after directory gets dirty, before regenerating.
    
      o Features (packages and install):
        - Add NSI installer contributed by J Doe.
        - Apply NT service patch from Osamu Fujino. Still needs more work.
        - Commit VC6 and VC7 workspace/project files.
        - Commit a tor.spec for making RPM files, with help from jbash.
        - Add contrib/torctl.in contributed by Glenn Fink.
        - Make expand_filename handle ~ and ~username.
        - Use autoconf to enable largefile support where necessary. Use
          ftello where available, since ftell can fail at 2GB.
        - Ship src/win32/ in the tarball, so people can use it to build.
        - Make old win32 fall back to CWD if SHGetSpecialFolderLocation
          is broken.
    
      o Features (ui controller):
        - Control interface: a separate program can now talk to your
          client/server over a socket, and get/set config options, receive
          notifications of circuits and streams starting/finishing/dying,
          bandwidth used, etc. The next step is to get some GUIs working.
          Let us know if you want to help out. See doc/control-spec.txt .
        - Ship a contrib/tor-control.py as an example script to interact
          with the control port.
        - "tor --hash-password zzyxz" will output a salted password for
          use in authenticating to the control interface.
        - Implement the control-spec's SAVECONF command, to write your
          configuration to torrc.
        - Get cookie authentication for the controller closer to working.
        - When set_conf changes our server descriptor, upload a new copy.
          But don't upload it too often if there are frequent changes.
    
      o Features (config and command-line):
        - Deprecate unofficial config option abbreviations, and abbreviations
          not on the command line.
        - Configuration infrastructure support for warning on obsolete
          options.
        - Give a slightly more useful output for "tor -h".
        - Break DirFetchPostPeriod into:
          - DirFetchPeriod for fetching full directory,
          - StatusFetchPeriod for fetching running-routers,
          - DirPostPeriod for posting server descriptor,
          - RendPostPeriod for posting hidden service descriptors.
        - New log format in config:
          "Log minsev[-maxsev] stdout|stderr|syslog" or
          "Log minsev[-maxsev] file /var/foo"
        - DirPolicy config option, to let people reject incoming addresses
          from their dirserver.
        - "tor --list-fingerprint" will list your identity key fingerprint
          and then exit.
        - Make tor --version --version dump the cvs Id of every file.
        - New 'MyFamily nick1,...' config option for a server to
          specify other servers that shouldn't be used in the same circuit
          with it. Only believed if nick1 also specifies us.
        - New 'NodeFamily nick1,nick2,...' config option for a client to
          specify nodes that it doesn't want to use in the same circuit.
        - New 'Redirectexit pattern address:port' config option for a
          server to redirect exit connections, e.g. to a local squid.
        - Add "pass" target for RedirectExit, to make it easier to break
          out of a sequence of RedirectExit rules.
        - Make the dirservers file obsolete.
          - Include a dir-signing-key token in directories to tell the
            parsing entity which key is being used to sign.
          - Remove the built-in bulky default dirservers string.
          - New config option "Dirserver %s:%d [fingerprint]", which can be
            repeated as many times as needed. If no dirservers specified,
            default to moria1,moria2,tor26.
          - Make 'Routerfile' config option obsolete.
        - Discourage people from setting their dirfetchpostperiod more often
          than once per minute.
    
      o Features (other):
        - kill -USR2 now moves all logs to loglevel debug (kill -HUP to
          get back to normal.)
        - Accept *:706 (silc) in default exit policy.
        - Implement new versioning format for post 0.1.
        - Distinguish between TOR_TLS_CLOSE and TOR_TLS_ERROR, so we can
          log more informatively.
        - Check clock skew for verified servers, but allow unverified
          servers and clients to have any clock skew.
        - Make sure the hidden service descriptors are at a random offset
          from each other, to hinder linkability.
        - Clients now generate a TLS cert too, in preparation for having
          them act more like real nodes.
        - Add a pure-C tor-resolve implementation.
        - Use getrlimit and friends to ensure we can reach MaxConn (currently
          1024) file descriptors.
        - Raise the max dns workers from 50 to 100.
    
    
    Changes in version 0.0.8.1 - 2004-10-13
      o Bugfixes:
        - Fix a seg fault that can be triggered remotely for Tor
          clients/servers with an open dirport.
        - Fix a rare assert trigger, where routerinfos for entries in
          our cpath would expire while we're building the path.
        - Fix a bug in OutboundBindAddress so it (hopefully) works.
        - Fix a rare seg fault for people running hidden services on
          intermittent connections.
        - Fix a bug in parsing opt keywords with objects.
        - Fix a stale pointer assert bug when a stream detaches and
          reattaches.
        - Fix a string format vulnerability (probably not exploitable)
          in reporting stats locally.
        - Fix an assert trigger: sometimes launching circuits can fail
          immediately, e.g. because too many circuits have failed recently.
        - Fix a compile warning on 64 bit platforms.
    
    
    Changes in version 0.0.8 - 2004-08-25
      o Bugfixes:
        - Made our unit tests compile again on OpenBSD 3.5, and tor
          itself compile again on OpenBSD on a sparc64.
        - We were neglecting milliseconds when logging on win32, so
          everything appeared to happen at the beginning of each second.
        - Check directory signature _before_ you decide whether you're
          you're running an obsolete version and should exit.
        - Check directory signature _before_ you parse the running-routers
          list to decide who's running.
        - Check return value of fclose while writing to disk, so we don't
          end up with broken files when servers run out of disk space.
        - Port it to SunOS 5.9 / Athena
        - Fix two bugs in saving onion keys to disk when rotating, so
          hopefully we'll get fewer people using old onion keys.
        - Remove our mostly unused -- and broken -- hex_encode()
          function. Use base16_encode() instead. (Thanks to Timo Lindfors
          for pointing out this bug.)
        - Only pick and establish intro points after we've gotten a
          directory.
        - Fix assert triggers: if the other side returns an address 0.0.0.0,
          don't put it into the client dns cache.
        - If a begin failed due to exit policy, but we believe the IP
          address should have been allowed, switch that router to exitpolicy
          reject *:* until we get our next directory.
    
      o Protocol changes:
        - 'Extend' relay cell payloads now include the digest of the
          intended next hop's identity key. Now we can verify that we're
          extending to the right router, and also extend to routers we
          hadn't heard of before.
    
      o Features:
        - Tor nodes can now act as relays (with an advertised ORPort)
          without being manually verified by the dirserver operators.
          - Uploaded descriptors of unverified routers are now accepted
            by the dirservers, and included in the directory.
          - Verified routers are listed by nickname in the running-routers
            list; unverified routers are listed as "$<fingerprint>".
          - We now use hash-of-identity-key in most places rather than
            nickname or addr:port, for improved security/flexibility.
          - AllowUnverifiedNodes config option to let circuits choose no-name
            routers in entry,middle,exit,introduction,rendezvous positions.
            Allow middle and rendezvous positions by default.
          - When picking unverified routers, skip those with low uptime and/or
            low bandwidth, depending on what properties you care about.
          - ClientOnly option for nodes that never want to become servers.
        - Directory caching.
          - "AuthoritativeDir 1" option for the official dirservers.
          - Now other nodes (clients and servers) will cache the latest
            directory they've pulled down.
          - They can enable their DirPort to serve it to others.
          - Clients will pull down a directory from any node with an open
            DirPort, and check the signature/timestamp correctly.
          - Authoritative dirservers now fetch directories from other
            authdirservers, to stay better synced.
          - Running-routers list tells who's down also, along with noting
            if they're verified (listed by nickname) or unverified (listed
            by hash-of-key).
          - Allow dirservers to serve running-router list separately.
            This isn't used yet.
          - You can now fetch $DIRURL/running-routers to get just the
            running-routers line, not the whole descriptor list. (But
            clients don't use this yet.)
        - Clients choose nodes proportional to advertised bandwidth.
        - Clients avoid using nodes with low uptime as introduction points.
        - Handle servers with dynamic IP addresses: don't just replace
          options->Address with the resolved one at startup, and
          detect our address right before we make a routerinfo each time.
        - 'FascistFirewall' option to pick dirservers and ORs on specific
          ports; plus 'FirewallPorts' config option to tell FascistFirewall
          which ports are open. (Defaults to 80,443)
        - Try other dirservers immediately if the one you try is down. This
          should tolerate down dirservers better now.
        - ORs connect-on-demand to other ORs
          - If you get an extend cell to an OR you're not connected to,
            connect, handshake, and forward the create cell.
          - The authoritative dirservers stay connected to everybody,
            and everybody stays connected to 0.0.7 servers, but otherwise
            clients/servers expire unused connections after 5 minutes.
        - When servers get a sigint, they delay 30 seconds (refusing new
          connections) then exit. A second sigint causes immediate exit.
        - File and name management:
          - Look for .torrc if no CONFDIR "torrc" is found.
          - If no datadir is defined, then choose, make, and secure ~/.tor
            as datadir.
          - If torrc not found, exitpolicy reject *:*.
          - Expands ~/ in filenames to $HOME/ (but doesn't yet expand ~arma).
          - If no nickname is defined, derive default from hostname.
          - Rename secret key files, e.g. identity.key -> secret_id_key,
            to discourage people from mailing their identity key to tor-ops.
        - Refuse to build a circuit before the directory has arrived --
          it won't work anyway, since you won't know the right onion keys
          to use.
        - Parse tor version numbers so we can do an is-newer-than check
          rather than an is-in-the-list check.
        - New socks command 'resolve', to let us shim gethostbyname()
          locally.
          - A 'tor_resolve' script to access the socks resolve functionality.
          - A new socks-extensions.txt doc file to describe our
            interpretation and extensions to the socks protocols.
        - Add a ContactInfo option, which gets published in descriptor.
        - Write tor version at the top of each log file
        - New docs in the tarball:
          - tor-doc.html.
          - Document that you should proxy your SSL traffic too.
        - Log a warning if the user uses an unsafe socks variant, so people
          are more likely to learn about privoxy or socat.
        - Log a warning if you're running an unverified server, to let you
          know you might want to get it verified.
        - Change the default exit policy to reject the default edonkey,
          kazaa, gnutella ports.
        - Add replace_file() to util.[ch] to handle win32's rename().
        - Publish OR uptime in descriptor (and thus in directory) too.
        - Remember used bandwidth (both in and out), and publish 15-minute
          snapshots for the past day into our descriptor.
        - Be more aggressive about trying to make circuits when the network
          has changed (e.g. when you unsuspend your laptop).
        - Check for time skew on http headers; report date in response to
          "GET /".
        - If the entrynode config line has only one node, don't pick it as
          an exitnode.
        - Add strict{entry|exit}nodes config options. If set to 1, then
          we refuse to build circuits that don't include the specified entry
          or exit nodes.
        - OutboundBindAddress config option, to bind to a specific
          IP address for outgoing connect()s.
        - End truncated log entries (e.g. directories) with "[truncated]".
    
    
    Changes in version 0.0.7.3 - 2004-08-12
      o Stop dnsworkers from triggering an assert failure when you
        ask them to resolve the host "".
    
    
    Changes in version 0.0.7.2 - 2004-07-07
      o A better fix for the 0.0.0.0 problem, that will hopefully
        eliminate the remaining related assertion failures.
    
    
    Changes in version 0.0.7.1 - 2004-07-04
      o When an address resolves to 0.0.0.0, treat it as a failed resolve,
        since internally we use 0.0.0.0 to signify "not yet resolved".
    
    
    Changes in version 0.0.7 - 2004-06-07
      o Fixes for crashes and other obnoxious bugs:
        - Fix an epipe bug: sometimes when directory connections failed
          to connect, we would give them a chance to flush before closing
          them.
        - When we detached from a circuit because of resolvefailed, we
          would immediately try the same circuit twice more, and then
          give up on the resolve thinking we'd tried three different
          exit nodes.
        - Limit the number of intro circuits we'll attempt to build for a
          hidden service per 15-minute period.
        - Check recommended-software string *early*, before actually parsing
          the directory. Thus we can detect an obsolete version and exit,
          even if the new directory format doesn't parse.
      o Fixes for security bugs:
        - Remember which nodes are dirservers when you startup, and if a
          random OR enables his dirport, don't automatically assume he's
          a trusted dirserver.
      o Other bugfixes:
        - Directory connections were asking the wrong poll socket to
          start writing, and not asking themselves to start writing.
        - When we detached from a circuit because we sent a begin but
          didn't get a connected, we would use it again the first time;
          but after that we would correctly switch to a different one.
        - Stop warning when the first onion decrypt attempt fails; they
          will sometimes legitimately fail now that we rotate keys.
        - Override unaligned-access-ok check when $host_cpu is ia64 or
          arm. Apparently they allow it but the kernel whines.
        - Dirservers try to reconnect periodically too, in case connections
          have failed.
        - Fix some memory leaks in directory servers.
        - Allow backslash in Win32 filenames.
        - Made Tor build complain-free on FreeBSD, hopefully without
          breaking other BSD builds. We'll see.
        - Check directory signatures based on name of signer, not on whom
          we got the directory from. This will let us cache directories more
          easily.
        - Rotate dnsworkers and cpuworkers on SIGHUP, so they get new config
          settings too.
      o Features:
        - Doxygen markup on all functions and global variables.
        - Make directory functions update routerlist, not replace it. So
          now directory disagreements are not so critical a problem.
        - Remove the upper limit on number of descriptors in a dirserver's
          directory (not that we were anywhere close).
        - Allow multiple logfiles at different severity ranges.
        - Allow *BindAddress to specify ":port" rather than setting *Port
          separately. Allow multiple instances of each BindAddress config
          option, so you can bind to multiple interfaces if you want.
        - Allow multiple exit policy lines, which are processed in order.
          Now we don't need that huge line with all the commas in it.
        - Enable accept/reject policies on SOCKS connections, so you can bind
          to 0.0.0.0 but still control who can use your OP.
        - Updated the man page to reflect these features.
    
    
    Changes in version 0.0.6.2 - 2004-05-16
      o Our integrity-checking digest was checking only the most recent cell,
        not the previous cells like we'd thought.
        Thanks to Stefan Mark for finding the flaw!
    
    
    Changes in version 0.0.6.1 - 2004-05-06
      o Fix two bugs in our AES counter-mode implementation (this affected
        onion-level stream encryption, but not TLS-level). It turns
        out we were doing something much more akin to a 16-character
        polyalphabetic cipher. Oops.
        Thanks to Stefan Mark for finding the flaw!
      o Retire moria3 as a directory server, and add tor26 as a directory
        server.
    
    
    Changes in version 0.0.6 - 2004-05-02
      o Features:
        - Hidden services and rendezvous points are implemented. Go to
          http://6sxoyfb3h2nvok2d.onion/ for an index of currently available
          hidden services. (This only works via a socks4a proxy such as
          Privoxy, and currently it's quite slow.)
        - We now rotate link (tls context) keys and onion keys.
        - CREATE cells now include oaep padding, so you can tell
          if you decrypted them correctly.
        - Retry stream correctly when we fail to connect because of
          exit-policy-reject (should try another) or can't-resolve-address.
        - When we hup a dirserver and we've *removed* a server from the
          approved-routers list, now we remove that server from the
          in-memory directories too.
        - Add bandwidthburst to server descriptor.
        - Directories now say which dirserver signed them.
        - Use a tor_assert macro that logs failed assertions too.
        - Since we don't support truncateds much, don't bother sending them;
          just close the circ.
        - Fetch randomness from /dev/urandom better (not via fopen/fread)
        - Better debugging for tls errors
        - Set Content-Type on the directory and hidserv descriptor.
        - Remove IVs from cipher code, since AES-ctr has none.
      o Bugfixes:
        - Fix an assert trigger for exit nodes that's been plaguing us since
          the days of 0.0.2prexx (thanks weasel!)
        - Fix a bug where we were closing tls connections intermittently.
          It turns out openssl keeps its errors around -- so if an error
          happens, and you don't ask about it, and then another openssl
          operation happens and succeeds, and you ask if there was an error,
          it tells you about the first error.
        - Fix a bug that's been lurking since 27 may 03 (!)
          When passing back a destroy cell, we would use the wrong circ id.
        - Don't crash if a conn that sent a begin has suddenly lost its circuit.
        - Some versions of openssl have an SSL_pending function that erroneously
          returns bytes when there is a non-application record pending.
        - Win32 fixes. Tor now compiles on win32 with no warnings/errors.
          o We were using an array of length zero in a few places.
          o Win32's gethostbyname can't resolve an IP to an IP.
          o Win32's close can't close a socket.
          o Handle windows socket errors correctly.
      o Portability:
        - check for <sys/limits.h> so we build on FreeBSD again, and
          <machine/limits.h> for NetBSD.
    
    
    Changes in version 0.0.5 - 2004-03-30
      o Install torrc as torrc.sample -- we no longer clobber your
        torrc. (Woo!)
      o Fix mangled-state bug in directory fetching (was causing sigpipes).
      o Only build circuits after we've fetched the directory: clients were
        using only the directory servers before they'd fetched a directory.
        This also means longer startup time; so it goes.
      o Fix an assert trigger where an OP would fail to handshake, and we'd
        expect it to have a nickname.
      o Work around a tsocks bug: do a socks reject when AP connection dies
        early, else tsocks goes into an infinite loop.
      o Hold socks connection open until reply is flushed (if possible)
      o Make exit nodes resolve IPs to IPs immediately, rather than asking
        the dns farm to do it.
      o Fix c99 aliasing warnings in rephist.c
      o Don't include server descriptors that are older than 24 hours in the
        directory.
      o Give socks 'reject' replies their whole 15s to attempt to flush,
        rather than seeing the 60s timeout and assuming the flush had failed.
      o Clean automake droppings from the cvs repository
      o Add in a 'notice' log level for things the operator should hear
        but that aren't warnings
    
    
    Changes in version 0.0.4 - 2004-03-26
      o When connecting to a dirserver or OR and the network is down,
        we would crash.
    
    
    Changes in version 0.0.3 - 2004-03-26
      o Warn and fail if server chose a nickname with illegal characters
      o Port to Solaris and Sparc:
        - include missing header fcntl.h
        - have autoconf find -lsocket -lnsl automatically
        - deal with hardware word alignment
        - make uname() work (solaris has a different return convention)
        - switch from using signal() to sigaction()
      o Preliminary work on reputation system:
        - Keep statistics on success/fail of connect attempts; they're published
          by kill -USR1 currently.
        - Add a RunTesting option to try to learn link state by creating test
          circuits, even when SocksPort is off.
        - Remove unused open circuits when there are too many.
    
    
    Changes in version 0.0.2 - 2004-03-19
        - Include strlcpy and strlcat for safer string ops
        - define INADDR_NONE so we compile (but still not run) on solaris
    
    
    Changes in version 0.0.2pre27 - 2004-03-14
      o Bugfixes:
        - Allow internal tor networks (we were rejecting internal IPs,
          now we allow them if they're set explicitly).
        - And fix a few endian issues.
    
    
    Changes in version 0.0.2pre26 - 2004-03-14
      o New features:
        - If a stream times out after 15s without a connected cell, don't
          try that circuit again: try a new one.
        - Retry streams at most 4 times. Then give up.
        - When a dirserver gets a descriptor from an unknown router, it
          logs its fingerprint (so the dirserver operator can choose to
          accept it even without mail from the server operator).
        - Inform unapproved servers when we reject their descriptors.
        - Make tor build on Windows again. It works as a client, who knows
          about as a server.
        - Clearer instructions in the torrc for how to set up a server.
        - Be more efficient about reading fd's when our global token bucket
          (used for rate limiting) becomes empty.
      o Bugfixes:
        - Stop asserting that computers always go forward in time. It's
          simply not true.
        - When we sent a cell (e.g. destroy) and then marked an OR connection
          expired, we might close it before finishing a flush if the other
          side isn't reading right then.
        - Don't allow dirservers to start if they haven't defined
          RecommendedVersions
        - We were caching transient dns failures. Oops.
        - Prevent servers from publishing an internal IP as their address.
        - Address a strcat vulnerability in circuit.c
    
    
    Changes in version 0.0.2pre25 - 2004-03-04
      o New features:
        - Put the OR's IP in its router descriptor, not its fqdn. That way
          we'll stop being stalled by gethostbyname for nodes with flaky dns,
          e.g. poblano.
      o Bugfixes:
        - If the user typed in an address that didn't resolve, the server
          crashed.
    
    
    Changes in version 0.0.2pre24 - 2004-03-03
      o Bugfixes:
        - Fix an assertion failure in dns.c, where we were trying to dequeue
          a pending dns resolve even if it wasn't pending
        - Fix a spurious socks5 warning about still trying to write after the
          connection is finished.
        - Hold certain marked_for_close connections open until they're finished
          flushing, rather than losing bytes by closing them too early.
        - Correctly report the reason for ending a stream
        - Remove some duplicate calls to connection_mark_for_close
        - Put switch_id and start_daemon earlier in the boot sequence, so it
          will actually try to chdir() to options.DataDirectory
        - Make 'make test' exit(1) if a test fails; fix some unit tests
        - Make tor fail when you use a config option it doesn't know about,
          rather than warn and continue.
        - Make --version work
        - Bugfixes on the rpm spec file and tor.sh, so it's more up to date
    
    
    Changes in version 0.0.2pre23 - 2004-02-29
      o New features:
        - Print a statement when the first circ is finished, so the user
          knows it's working.
        - If a relay cell is unrecognized at the end of the circuit,
          send back a destroy. (So attacks to mutate cells are more
          clearly thwarted.)
        - New config option 'excludenodes' to avoid certain nodes for circuits.
        - When it daemonizes, it chdir's to the DataDirectory rather than "/",
          so you can collect coredumps there.
     o Bugfixes:
        - Fix a bug in tls flushing where sometimes data got wedged and
          didn't flush until more data got sent. Hopefully this bug was
          a big factor in the random delays we were seeing.
        - Make 'connected' cells include the resolved IP, so the client
          dns cache actually gets populated.
        - Disallow changing from ORPort=0 to ORPort>0 on hup.
        - When we time-out on a stream and detach from the circuit, send an
          end cell down it first.
        - Only warn about an unknown router (in exitnodes, entrynodes,
          excludenodes) after we've fetched a directory.
    
    
    Changes in version 0.0.2pre22 - 2004-02-26
      o New features:
        - Servers publish less revealing uname information in descriptors.
        - More memory tracking and assertions, to crash more usefully when
          errors happen.
        - If the default torrc isn't there, just use some default defaults.
          Plus provide an internal dirservers file if they don't have one.
        - When the user tries to use Tor as an http proxy, give them an http
          501 failure explaining that we're a socks proxy.
        - Dump a new router.desc on hup, to help confused people who change
          their exit policies and then wonder why router.desc doesn't reflect
          it.
        - Clean up the generic tor.sh init script that we ship with.
      o Bugfixes:
        - If the exit stream is pending on the resolve, and a destroy arrives,
          then the stream wasn't getting removed from the pending list. I
          think this was the one causing recent server crashes.
        - Use a more robust poll on OSX 10.3, since their poll is flaky.
        - When it couldn't resolve any dirservers, it was useless from then on.
          Now it reloads the RouterFile (or default dirservers) if it has no
          dirservers.
        - Move the 'tor' binary back to /usr/local/bin/ -- it turns out
          many users don't even *have* a /usr/local/sbin/.
    
    
    Changes in version 0.0.2pre21 - 2004-02-18
      o New features:
        - There's a ChangeLog file that actually reflects the changelog.
        - There's a 'torify' wrapper script, with an accompanying
          tor-tsocks.conf, that simplifies the process of using tsocks for
          tor. It even has a man page.
        - The tor binary gets installed to sbin rather than bin now.
        - Retry streams where the connected cell hasn't arrived in 15 seconds
        - Clean up exit policy handling -- get the default out of the torrc,
          so we can update it without forcing each server operator to fix
          his/her torrc.
        - Allow imaps and pop3s in default exit policy
      o Bugfixes:
        - Prevent picking middleman nodes as the last node in the circuit
    
    
    Changes in version 0.0.2pre20 - 2004-01-30
      o New features:
        - We now have a deb package, and it's in debian unstable. Go to
          it, apt-getters. :)
        - I've split the TotalBandwidth option into BandwidthRate (how many
          bytes per second you want to allow, long-term) and
          BandwidthBurst (how many bytes you will allow at once before the cap
          kicks in).  This better token bucket approach lets you, say, set
          BandwidthRate to 10KB/s and BandwidthBurst to 10MB, allowing good
          performance while not exceeding your monthly bandwidth quota.
        - Push out a tls record's worth of data once you've got it, rather
          than waiting until you've read everything waiting to be read. This
          may improve performance by pipelining better. We'll see.
        - Add an AP_CONN_STATE_CONNECTING state, to allow streams to detach
          from failed circuits (if they haven't been connected yet) and attach
          to new ones.
        - Expire old streams that haven't managed to connect. Some day we'll
          have them reattach to new circuits instead.
    
      o Bugfixes:
        - Fix several memory leaks that were causing servers to become bloated
          after a while.
        - Fix a few very rare assert triggers. A few more remain.
        - Setuid to User _before_ complaining about running as root.
    
    
    Changes in version 0.0.2pre19 - 2004-01-07
      o Bugfixes:
        - Fix deadlock condition in dns farm. We were telling a child to die by
          closing the parent's file descriptor to him. But newer children were
          inheriting the open file descriptor from the parent, and since they
          weren't closing it, the socket never closed, so the child never read
          eof, so he never knew to exit. Similarly, dns workers were holding
          open other sockets, leading to all sorts of chaos.
        - New cleaner daemon() code for forking and backgrounding.
        - If you log to a file, it now prints an entry at the top of the
          logfile so you know it's working.
        - The onionskin challenge length was 30 bytes longer than necessary.
        - Started to patch up the spec so it's not quite so out of date.
    
    
    Changes in version 0.0.2pre18 - 2004-01-02
      o Bugfixes:
        - Fix endian issues with the 'integrity' field in the relay header.
        - Fix a potential bug where connections in state
          AP_CONN_STATE_CIRCUIT_WAIT might unexpectedly ask to write.
    
    
    Changes in version 0.0.2pre17 - 2003-12-30
      o Bugfixes:
        - Made --debuglogfile (or any second log file, actually) work.
        - Resolved an edge case in get_unique_circ_id_by_conn where a smart
          adversary could force us into an infinite loop.
    
      o Features:
        - Each onionskin handshake now includes a hash of the computed key,
          to prove the server's identity and help perfect forward secrecy.
        - Changed cell size from 256 to 512 bytes (working toward compatibility
          with MorphMix).
        - Changed cell length to 2 bytes, and moved it to the relay header.
        - Implemented end-to-end integrity checking for the payloads of
          relay cells.
        - Separated streamid from 'recognized' (otherwise circuits will get
          messed up when we try to have streams exit from the middle). We
          use the integrity-checking to confirm that a cell is addressed to
          this hop.
        - Randomize the initial circid and streamid values, so an adversary who
          breaks into a node can't learn how many circuits or streams have
          been made so far.
    
    
    Changes in version 0.0.2pre16 - 2003-12-14
      o Bugfixes:
        - Fixed a bug that made HUP trigger an assert
        - Fixed a bug where a circuit that immediately failed wasn't being
          counted as a failed circuit in counting retries.
    
      o Features:
        - Now we close the circuit when we get a truncated cell: otherwise we're
          open to an anonymity attack where a bad node in the path truncates
          the circuit and then we open streams at him.
        - Add port ranges to exit policies
        - Add a conservative default exit policy
        - Warn if you're running tor as root
        - on HUP, retry OR connections and close/rebind listeners
        - options.EntryNodes: try these nodes first when picking the first node
        - options.ExitNodes: if your best choices happen to include any of
          your preferred exit nodes, you choose among just those preferred
          exit nodes.
        - options.ExcludedNodes: nodes that are never picked in path building
    
    
    Changes in version 0.0.2pre15 - 2003-12-03
      o Robustness and bugfixes:
        - Sometimes clients would cache incorrect DNS resolves, which would
          really screw things up.
        - An OP that goes offline would slowly leak all its sockets and stop
          working.
        - A wide variety of bugfixes in exit node selection, exit policy
          handling, and processing pending streams when a new circuit is
          established.
        - Pick nodes for a path only from those the directory says are up
        - Choose randomly from all running dirservers, not always the first one
        - Increase allowed http header size for directory fetch.
        - Stop writing to stderr (if we're daemonized it will be closed).
        - Enable -g always, so cores will be more useful to me.
        - Switch "-lcrypto -lssl" to "-lssl -lcrypto" for broken distributions.
    
      o Documentation:
        - Wrote a man page. It lists commonly used options.
    
      o Configuration:
        - Change default loglevel to warn.
        - Make PidFile default to null rather than littering in your CWD.
        - OnionRouter config option is now obsolete. Instead it just checks
          ORPort>0.
        - Moved to a single unified torrc file for both clients and servers.
    
    
    Changes in version 0.0.2pre14 - 2003-11-29
      o Robustness and bugfixes:
        - Force the admin to make the DataDirectory himself
          - to get ownership/permissions right
          - so clients no longer make a DataDirectory and then never use it
        - fix bug where a client who was offline for 45 minutes would never
          pull down a directory again
        - fix (or at least hide really well) the dns assert bug that was
          causing server crashes
        - warnings and improved robustness wrt clockskew for certs
        - use the native daemon(3) to daemonize, when available
        - exit if bind() fails
        - exit if neither socksport nor orport is defined
        - include our own tor_timegm (Win32 doesn't have its own)
        - bugfix for win32 with lots of connections
        - fix minor bias in PRNG
        - make dirserver more robust to corrupt cached directory
    
      o Documentation:
        - Wrote the design document (woo)
    
      o Circuit building and exit policies:
        - Circuits no longer try to use nodes that the directory has told them
          are down.
        - Exit policies now support bitmasks (18.0.0.0/255.0.0.0) and
          bitcounts (18.0.0.0/8).
        - Make AP connections standby for a circuit if no suitable circuit
          exists, rather than failing
        - Circuits choose exit node based on addr/port, exit policies, and
          which AP connections are standing by
        - Bump min pathlen from 2 to 3
        - Relay end cells have a payload to describe why the stream ended.
        - If the stream failed because of exit policy, try again with a new
          circuit.
        - Clients have a dns cache to remember resolved addresses.
        - Notice more quickly when we have no working circuits
    
      o Configuration:
        - APPort is now called SocksPort
        - SocksBindAddress, ORBindAddress, DirBindAddress let you configure
          where to bind
        - RecommendedVersions is now a config variable rather than
          hardcoded (for dirservers)
        - Reloads config on HUP
        - Usage info on -h or --help
        - If you set User and Group config vars, it'll setu/gid to them.
    
    Changes in version 0.0.2pre13 - 2003-10-19
      o General stability:
        - SSL_write no longer fails when it returns WANTWRITE and the number
          of bytes in the buf has changed by the next SSL_write call.
        - Fix segfault fetching directory when network is down
        - Fix a variety of minor memory leaks
        - Dirservers reload the fingerprints file on HUP, so I don't have
          to take down the network when I approve a new router
        - Default server config file has explicit Address line to specify fqdn
    
      o Buffers:
        - Buffers grow and shrink as needed (Cut process size from 20M to 2M)
        - Make listener connections not ever alloc bufs
    
      o Autoconf improvements:
        - don't clobber an external CFLAGS in ./configure
        - Make install now works
        - create var/lib/tor on make install
        - autocreate a tor.sh initscript to help distribs
        - autocreate the torrc and sample-server-torrc with correct paths
    
      o Log files and Daemonizing now work:
        - If --DebugLogFile is specified, log to it at -l debug
        - If --LogFile is specified, use it instead of commandline
        - If --RunAsDaemon is set, tor forks and backgrounds on startup