[tor-bugs] #1517 [Applications/Tor Browser]: Provide JS with reduced time precision

Tor Bug Tracker & Wiki blackhole at torproject.org
Thu Aug 1 18:52:37 UTC 2019


#1517: Provide JS with reduced time precision
-------------------------------------------------+-------------------------
 Reporter:  mikeperry                            |          Owner:  (none)
     Type:  enhancement                          |         Status:  closed
 Priority:  High                                 |      Milestone:
Component:  Applications/Tor Browser             |        Version:
 Severity:                                       |     Resolution:  fixed
 Keywords:  backport-to-mozilla, tbb-torbutton,  |  Actual Points:
  tbb-fingerprinting-time-highres, ff38-esr,     |
  TorBrowserTeam201505R, PearlCrescent201505R    |
Parent ID:                                       |         Points:  10
-------------------------------------------------+-------------------------

Comment (by Thorin):

 Replying to [comment:32 mikeperry]:
 > I looked into this more, and noticed one case where ToSeconds() was
 exposed to content. AnimationFrame events have an elapsedTime field. I
 truncated that timestamp to millisecond accuracy (though in reality, the
 timestamps were varying by as much as 20ms for me).

 Hi Mike ... I'm 4 years late to the party... but I'm doing some "work" on
 some current (and open / unpatched) timing attacks - and the reason AFAIK
 is that 60fps = 16ms

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/1517#comment:33>
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