Set network.proxy.socks_remote_dns=false inside the Firefox helper.

We need this setting to be false in order for DNS lookups to work outside of a proxy, when the extension is run in Tor Browser (https://trac.torproject.org/projects/tor/ticket/11183#comment:6). By setting the pref inside the extension, we don't rely on it being set in the user.js file, where it can instead have its default value of true, which is safer if the browser somehow runs without the extension. https://trac.torproject.org/projects/tor/ticket/12674#comment:2

Set network.proxy.socks_remote_dns=false inside the Firefox helper.
32ca07ca · David Fifield · 52b9014c · 32ca07ca
Commit 32ca07ca authored 10 years ago by David Fifield
--- a/firefox/components/main.js
+++ b/firefox/components/main.js
@@ -62,6 +62,14 @@ MeekHTTPHelper.prototype = {
            return;

        try {
+            var prefs = Components.classes["@mozilla.org/preferences-service;1"]
+                .getService(Components.interfaces.nsIPrefBranch);
+            // Allow unproxied DNS, working around a Tor Browser patch:
+            // https://trac.torproject.org/projects/tor/ticket/11183#comment:6.
+            // We set TRANSPARENT_PROXY_RESOLVES_HOST whenever we are asked to
+            // use a proxy, so name resolution uses the proxy despite this pref.
+            prefs.setBoolPref("network.proxy.socks_remote_dns", false);
+
            // https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIServerSocket
            var serverSocket = Components.classes["@mozilla.org/network/server-socket;1"]
                .createInstance(Components.interfaces.nsIServerSocket);