[tor-bugs] #21792 [Applications/Tor Browser]: Make sure MediaError.message does not aid to fingerprinting

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#21792: Make sure MediaError.message does not aid to fingerprinting
-------------------------------------------------+-------------------------
 Reporter:  gk                                   |          Owner:
                                                 |  arthuredelstein
     Type:  defect                               |         Status:
                                                 |  needs_review
 Priority:  High                                 |      Milestone:
Component:  Applications/Tor Browser             |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  ff52-esr, tbb-fingerprinting,        |  Actual Points:
  tbb-7.0-must-alpha, TorBrowserTeam201704R      |
Parent ID:                                       |         Points:
 Reviewer:                                       |        Sponsor:
-------------------------------------------------+-------------------------
Changes (by arthuredelstein):

 * status:  accepted => needs_review
 * keywords:  ff52-esr, tbb-fingerprinting, tbb-7.0-must-alpha,
     TorBrowserTeam201704 =>
     ff52-esr, tbb-fingerprinting, tbb-7.0-must-alpha,
     TorBrowserTeam201704R


Comment:

 I did a lot of exploration of the code that generates MediaError.messages.
 I didn't find any that seemed likely to reveal any system information. On
 the other hand, I may have missed a case, and I can imagine more privacy-
 violating messages might be introduced in the future. So, to be safe,  I
 wrote a patch that censors any messages when
 "privacy.resistFingerprinting" is enabled:

 https://github.com/arthuredelstein/tor-browser/commit/21792

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21792#comment:9>
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