commit 8869cf4f01341dd685508afb2b2a10b9b3ea0f26 Author: Isis Lovecruft isis@torproject.org Date: Thu Jan 21 03:37:43 2016 +0000

Bug 18113: Randomly permutate available default bridges of chosen type.

* ADDS a new function to TorLauncherUtil, rearrangeBridges() which takes an array of items and returns a random permutation of that array.

* CHANGE defaultBridges() getter to call this.rearrangeBridges() before returning the default bridges. This causing the ordering of the default bridges in the torrc to vary among clients, resulting in a more even distribution of clients to default bridges. --- src/modules/tl-util.jsm | 14 ++++++++++++++ 1 file changed, 14 insertions(+)

diff --git a/src/modules/tl-util.jsm b/src/modules/tl-util.jsm index 812b32b..7f93f39 100644 --- a/src/modules/tl-util.jsm +++ b/src/modules/tl-util.jsm @@ -246,6 +246,19 @@ let TorLauncherUtil = // Public } catch (e) {} },

+ // Currently, this returns a random permutation of an array, bridgeArray. + // Later, we might want to change this function to weight based on the + // bridges' bandwidths. + rearrangeBridges: function(bridgeArray) + { + for (var j, x, i = bridgeArray.length; i; + j = parseInt(Math.random() * i), + x = bridgeArray[--i], + bridgeArray[i] = bridgeArray[j], + bridgeArray[j] = x); + return bridgeArray; + }, + get shouldStartAndOwnTor() { const kPrefStartTor = "extensions.torlauncher.start_tor"; @@ -361,6 +374,7 @@ let TorLauncherUtil = // Public bridgeArray.push(s); } } + this.rearrangeBridges(bridgeArray);

return bridgeArray; } catch(e) {};