diff options
| -rw-r--r-- | proxy/snowflake.coffee | 4 | ||||
| -rw-r--r-- | proxy/websocket.coffee | 2 | ||||
| -rw-r--r-- | server/server.go | 111 | ||||
| -rw-r--r-- | server/torrc | 4 |
4 files changed, 89 insertions, 32 deletions
diff --git a/proxy/snowflake.coffee b/proxy/snowflake.coffee index 1fff686..38d7d08 100644 --- a/proxy/snowflake.coffee +++ b/proxy/snowflake.coffee @@ -9,8 +9,8 @@ this must always act as the answerer. ### DEFAULT_BROKER = 'snowflake-reg.appspot.com' DEFAULT_RELAY = - host: '192.81.135.242' - port: 9902 + host: 'snowflake.bamsoftware.com' + port: 443 COPY_PASTE_ENABLED = false COOKIE_NAME = "snowflake-allow" diff --git a/proxy/websocket.coffee b/proxy/websocket.coffee index 94cf274..75c7a2f 100644 --- a/proxy/websocket.coffee +++ b/proxy/websocket.coffee @@ -46,7 +46,7 @@ buildUrl = (scheme, host, port, path, params) -> parts.join '' makeWebsocket = (addr) -> - url = buildUrl 'ws', addr.host, addr.port, '/' + url = buildUrl 'wss', addr.host, addr.port, '/' ws = new WebSocket url ### 'User agents can use this as a hint for how to handle incoming binary data: if diff --git a/server/server.go b/server/server.go index 8025ad3..aec9b51 100644 --- a/server/server.go +++ b/server/server.go @@ -19,12 +19,15 @@ import ( "net/http" "os" "os/signal" + "path/filepath" + "strings" "sync" "syscall" "time" "git.torproject.org/pluggable-transports/goptlib.git" "git.torproject.org/pluggable-transports/websocket.git/websocket" + "golang.org/x/crypto/acme/autocert" ) const ptMethodName = "snowflake" @@ -39,11 +42,15 @@ var ptInfo pt.ServerInfo var handlerChan = make(chan int) func usage() { - fmt.Printf("Usage: %s [OPTIONS]\n\n", os.Args[0]) - fmt.Printf("WebSocket server pluggable transport for Tor.\n") - fmt.Printf("Works only as a managed proxy.\n") - fmt.Printf("\n") - fmt.Printf(" -h, -help show this help.\n") + fmt.Fprintf(os.Stderr, `Usage: %s [OPTIONS] + +WebSocket server pluggable transport for Snowflake. Works only as a managed +proxy. Uses TLS with ACME (Let's Encrypt) by default. Set the certificate +hostnames with the --acme-hostnames option. Use ServerTransportListenAddr in +torrc to choose the listening port. When using TLS, if the port is not 443, this +program will open an additional listening port on 443 to work with ACME. + +`, os.Args[0]) flag.PrintDefaults() } @@ -150,7 +157,7 @@ func webSocketHandler(ws *websocket.WebSocket) { proxy(or, &conn) } -func listenTLS(network string, addr *net.TCPAddr, certFilename, keyFilename string) (net.Listener, error) { +func listenTLS(network string, addr *net.TCPAddr, m *autocert.Manager) (net.Listener, error) { // This is cribbed from the source of net/http.Server.ListenAndServeTLS. // We have to separate the Listen and Serve parts because we need to // report the listening address before entering Serve (which is an @@ -158,13 +165,7 @@ func listenTLS(network string, addr *net.TCPAddr, certFilename, keyFilename stri // https://groups.google.com/d/msg/Golang-nuts/3F1VRCCENp8/3hcayZiwYM8J config := &tls.Config{} config.NextProtos = []string{"http/1.1"} - - var err error - config.Certificates = make([]tls.Certificate, 1) - config.Certificates[0], err = tls.LoadX509KeyPair(certFilename, keyFilename) - if err != nil { - return nil, err - } + config.GetCertificate = m.GetCertificate conn, err := net.ListenTCP(network, addr) if err != nil { @@ -190,8 +191,8 @@ func startListener(network string, addr *net.TCPAddr) (net.Listener, error) { return startServer(ln) } -func startListenerTLS(network string, addr *net.TCPAddr, certFilename, keyFilename string) (net.Listener, error) { - ln, err := listenTLS(network, addr, certFilename, keyFilename) +func startListenerTLS(network string, addr *net.TCPAddr, m *autocert.Manager) (net.Listener, error) { + ln, err := listenTLS(network, addr, m) if err != nil { return nil, err } @@ -216,15 +217,24 @@ func startServer(ln net.Listener) (net.Listener, error) { return ln, nil } +func getCertificateCacheDir() (string, error) { + stateDir, err := pt.MakeStateDir() + if err != nil { + return "", err + } + return filepath.Join(stateDir, "snowflake-certificate-cache"), nil +} + func main() { + var acmeEmail string + var acmeHostnamesCommas string var disableTLS bool - var certFilename, keyFilename string var logFilename string flag.Usage = usage + flag.StringVar(&acmeEmail, "acme-email", "", "optional contact email for Let's Encrypt notifications") + flag.StringVar(&acmeHostnamesCommas, "acme-hostnames", "", "comma-separated hostnames for TLS certificate") flag.BoolVar(&disableTLS, "disable-tls", false, "don't use HTTPS") - flag.StringVar(&certFilename, "cert", "", "TLS certificate file (required without --disable-tls)") - flag.StringVar(&keyFilename, "key", "", "TLS private key file (required without --disable-tls)") flag.StringVar(&logFilename, "log", "", "log file to write to") flag.Parse() @@ -237,15 +247,10 @@ func main() { log.SetOutput(f) } - if disableTLS { - if certFilename != "" || keyFilename != "" { - log.Fatalf("the --cert and --key options are not allowed with --disable-tls") - } - } else { - if certFilename == "" || keyFilename == "" { - log.Fatalf("the --cert and --key options are required") - } + if !disableTLS && acmeHostnamesCommas == "" { + log.Fatal("the --acme-hostnames option is required") } + acmeHostnames := strings.Split(acmeHostnamesCommas, ",") log.Printf("starting") var err error @@ -254,6 +259,41 @@ func main() { log.Fatalf("error in setup: %s", err) } + var certManager *autocert.Manager + if !disableTLS { + log.Printf("ACME hostnames: %q", acmeHostnames) + + var cache autocert.Cache + cacheDir, err := getCertificateCacheDir() + if err == nil { + log.Printf("caching ACME certificates in directory %q", cacheDir) + cache = autocert.DirCache(cacheDir) + } else { + log.Printf("disabling ACME certificate cache: %s", err) + } + + certManager = &autocert.Manager{ + Prompt: autocert.AcceptTOS, + HostPolicy: autocert.HostWhitelist(acmeHostnames...), + Email: acmeEmail, + Cache: cache, + } + } + + // The ACME responder only works when it is running on port 443. In case + // there is not already going to be a TLS listener on port 443, we need + // to open an additional one. The port is actually opened in the loop + // below, so that any errors can be reported in the SMETHOD-ERROR of + // another bindaddr. + // https://letsencrypt.github.io/acme-spec/#domain-validation-with-server-name-indication-dvsni + need443Listener := !disableTLS + for _, bindaddr := range ptInfo.Bindaddrs { + if !disableTLS && bindaddr.Addr.Port == 443 { + need443Listener = false + break + } + } + listeners := make([]net.Listener, 0) for _, bindaddr := range ptInfo.Bindaddrs { if bindaddr.MethodName != ptMethodName { @@ -261,6 +301,20 @@ func main() { continue } + if need443Listener { + addr := *bindaddr.Addr + addr.Port = 443 + log.Printf("opening additional ACME listener on %s", addr.String()) + ln443, err := startListenerTLS("tcp", &addr, certManager) + if err != nil { + log.Printf("error opening ACME listener: %s", err) + pt.SmethodError(bindaddr.MethodName, "ACME listener: "+err.Error()) + continue + } + listeners = append(listeners, ln443) + need443Listener = false + } + var ln net.Listener args := pt.Args{} if disableTLS { @@ -268,7 +322,10 @@ func main() { ln, err = startListener("tcp", bindaddr.Addr) } else { args.Add("tls", "yes") - ln, err = startListenerTLS("tcp", bindaddr.Addr, certFilename, keyFilename) + for _, hostname := range acmeHostnames { + args.Add("hostname", hostname) + } + ln, err = startListenerTLS("tcp", bindaddr.Addr, certManager) } if err != nil { log.Printf("error opening listener: %s", err) diff --git a/server/torrc b/server/torrc index 74f6af0..ed71a39 100644 --- a/server/torrc +++ b/server/torrc @@ -5,5 +5,5 @@ SocksPort 0 ExitPolicy reject *:* DataDirectory datadir -ServerTransportListenAddr snowflake 0.0.0.0:9902 -ServerTransportPlugin snowflake exec ./server --disable-tls --log snowflake.log +ServerTransportListenAddr snowflake 0.0.0.0:443 +ServerTransportPlugin snowflake exec ./server --acme-hostnames snowflake.example --acme-email admin@snowflake.example --log snowflake.log |