[tbb-bugs] #12621 [Tor Browser]: Review and audit Firefox changes since Firefox 24

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#12621: Review and audit Firefox changes since Firefox 24
-------------------------+-------------------------------------------------
     Reporter:  gk       |      Owner:  tbb-team
         Type:  task     |     Status:  new
     Priority:  major    |  Milestone:
    Component:  Tor      |    Version:
  Browser                |   Keywords:  MikePerry201408,
   Resolution:           |  TorBrowserTeam201408, ff31-esr, tbb-rebase,
Actual Points:           |  tbb-firefox-patch
       Points:           |  Parent ID:
-------------------------+-------------------------------------------------

Comment (by mikeperry):

 Ok, here are my notes from the review of the developer docs and the
 undocumented bugs, by Firefox version:

  - FF25:
    - Fingerprintable:
      - https://developer.mozilla.org/en-
 US/docs/Web/Guide/CSS/Media_queries#-moz-os-version
        - We probably should kill all of the Mozilla media query
 extensions.
          They all suck.
      - -moz-osx-font-smoothing:
 https://bugzilla.mozilla.org/show_bug.cgi?id=857142
      - HTMLCanvas.toBlob() changes (and other new APIs?)
        - https://developer.mozilla.org/en-
 US/docs/Web/API/CanvasRenderingContext2D
        - https://developer.mozilla.org/en-US/docs/Web/API/ImageData
    - Maybe fingerprintable:
      - https://developer.mozilla.org/en-US/docs/Web_Audio_API
        - AudioBuffer.copyTo/FromBuffer and related APIs might allow
 fingerprinting if
          OS-dependent libraries are used for FFT and other effect
          generation
      - https://developer.mozilla.org/en-
 US/docs/Web/JavaScript/Reference/Global_Objects/Math
        - High-precision Math routines might allow OS/version fingeprinting
      - WebGL1 extensions become features:
 https://bugzilla.mozilla.org/show_bug.cgi?id=890379
  - FF26:
    - Fingerprintable:
      - https://developer.mozilla.org/en-US/docs/Web/API/Screen.orientation
  - FF27:
    - Maybe fingerprintable:
      - https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input
 #attr-type
        - Some of these field values may be locale-fingerprintable?
  - FF28:
    - Maybe fingerprintable:
      - https://developer.mozilla.org/en-US/docs/Web/CSS/font-variant-
 ligatures
    - Conflicts:
      - window.screenX/Y reports CSS pixels:
 https://bugzilla.mozilla.org/show_bug.cgi?id=943668
      - Ensure navigator useragent/platform elements are still spoofed in
 workers:
        https://bugzilla.mozilla.org/show_bug.cgi?id=925847
  - FF29:
    - Fingerprinting:
      - https://developer.mozilla.org/en-
 US/docs/Web/JavaScript/Reference/Global_Objects/Intl
        - http://www.ecma-international.org/ecma-402/1.0/
        - String/Number/Date all have *locale* versions
      - https://developer.mozilla.org/en-US/docs/Web/Guide/API/Gamepad
      - Hint that JS wants to read canvas:
        https://bugzilla.mozilla.org/show_bug.cgi?id=884226
  - FF30:
    - Maybe fingerprintable:
      - Canvas HitRegions?
        - https://bugzilla.mozilla.org/show_bug.cgi?id=966591
    - Proxy safety:
      - Is Gstreamer proxy-safe?
    - Maybe tracking:
      - Can content-created elements persist? Probably not.
        - https://bugzilla.mozilla.org/show_bug.cgi?id=856140
  - FF31:
    - Resource timing: https://bugzilla.mozilla.org/show_bug.cgi?id=822480

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/12621#comment:6>
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