[tor-bugs] #13019 [Tor Browser]: New locale fingerprinting capabilities in FF31ESR

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#13019: New locale fingerprinting capabilities in FF31ESR
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     Reporter:           |      Owner:  arthuredelstein
  mikeperry              |     Status:  needs_revision
         Type:  defect   |  Milestone:
     Priority:  major    |    Version:
    Component:  Tor      |   Keywords:  ff31-esr, tbb-fingerprinting,
  Browser                |  TorBrowserTeam201503, tbb-4.5-alpha
   Resolution:           |  Parent ID:
Actual Points:           |
       Points:           |
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Comment (by arthuredelstein):

 Replying to [comment:24 gk]:
 > Replying to [comment:23 arthuredelstein]:
 > > After further discussion with Mike, I have kept the boolean pref, but
 renamed it to javascript.use_us_english_locale
 > >
 > > Here's the revised patch for Tor Browser:
 > > https://github.com/arthuredelstein/tor-
 browser/commit/917f5dfb669585ceb4b42f68ed93988ada61e158
 > >
 > > And the accompanying patch for torbutton:
 > >
 https://github.com/arthuredelstein/torbutton/commit/dcbd97834f991c6b4ef5f86154e6823251511075
 >
 > These patches do not solve the problem. I made sure I really built Tor
 Browser with the commit above and had the proper Torbutton version
 running. Still, the locale of the OS was not spoofed.

 I'm still having difficulty getting my Windows cross-compile to work.
 However, I think I understand better now what is happening on Windows. It
 turns out that Windows does not accept the "en_US" locale in
 `setlocale(...)`. Instead you have to use "English_United States.1252". I
 used the latest alpha version of Tor Browser and set
 "javascript.default_locale" to "English_United States.1252". In that case,
 http://www.fixtheworldproject.net/ shows US English-formatted dates on
 Windows 7 when the system locale is set to German. As does
 Date().toLocaleString().

 So I'm posting an extra fixup patch to my 13019+3 branch:
 https://github.com/arthuredelstein/tor-browser/commits/13019%2B3

 I would be grateful if someone could build this and test on Windows.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/13019#comment:26>
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