[tor-bugs] #19417 [Applications/Tor Browser]: asm.js files should be no linkability risk

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#19417: asm.js files should be no linkability risk
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 Reporter:  gk                                   |          Owner:  tbb-
                                                 |  team
     Type:  defect                               |         Status:
                                                 |  assigned
 Priority:  Medium                               |      Milestone:
Component:  Applications/Tor Browser             |        Version:
 Severity:  Major                                |     Resolution:
 Keywords:  tbb-linkability, GeorgKoppen201609,  |  Actual Points:
  ff68-esr, TorBrowserTeam201909                 |
Parent ID:                                       |         Points:
 Reviewer:                                       |        Sponsor:
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Comment (by acat):

 I do not see any asm.js cache, disk or in-memory.

 It's not a strong proof, but I did a quick test with
 https://kripken.github.io/Massive/ (there are console logs with asm.js
 compilation time). Testing with Firefox 64, where caching was still
 enabled, shows that for cached asm.js loading time is much faster (like
 50ms vs 1000ms). In 68 there is no difference in times, either in PBM or
 "persisting" mode.

 Regarding comment:32, if the disk leak was solved (in
 https://bugzilla.mozilla.org/show_bug.cgi?id=1047105), what were the FPI
 concerns back then? Was there an in-memory cache that did not respect FPI?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/19417#comment:40>
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