[tbb-bugs] #30537 [Applications/Tor Browser]: WebGL fingerprint is different between Windows versions (and compared to non-Windows OSes)

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#30537: WebGL fingerprint is different between Windows versions (and compared to
non-Windows OSes)
-------------------------------------------------+-------------------------
 Reporter:  gk                                   |          Owner:  tbb-
                                                 |  team
     Type:  defect                               |         Status:  new
 Priority:  High                                 |      Milestone:
Component:  Applications/Tor Browser             |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tbb-fingerprinting, tbb-             |  Actual Points:
  fingerprinting-os                              |
Parent ID:                                       |         Points:
 Reviewer:                                       |        Sponsor:
-------------------------------------------------+-------------------------

Comment (by Thorin):

 **FWIW**:

 Win 7 64bit (bare metal) just 8.5a12 64bit
 - `224a8abee799ec6381e06293de4565f6`
 - 2x Error: WebGL warning: Exceeded 16 live WebGL contexts...

 Win 7 32bit (VM)
 - `224a8abee799ec6381e06293de4565f6`
 - 17x Error: WebGL warning: Disallowing antialiased backbuffers due to
 blacklisting
 - then 1x Error: WebGL warning: Exceeded 16 live WebGL contexts...
 - then 1x Error: WebGL warning: Disallowing antialiased backbuffers...
 - repeat the last two lines about a dozen times

 Win10 64bit (VM) 8.5.a12 64bit & 32bit
 - `6992168724b997c74fc89f1e4a9301ce`
 - a plethora of errors

 ---

 **Please advise**: I was going to open another ticket when I had done some
 more testing, but **readPixels** is not covered by RFP (see
 https://bugzilla.mozilla.org/show_bug.cgi?id=1428034 ) and using my tests
 [1], on windows I get entropy. Not sure if unique or just OS.

 - Windows 7 32bit
 `2ba61e7e8e370fdbcefb79456e7e944b060f34289af33732aa6eb75af61ff06c`
 - Windows 7 64bit
 `ac9aa378cd16219ecbcb6ec46b57d8a484ac8ad61cbe63c810b40fb2c741e7f3`
 - Windows10 64bit
 `c4ef81818ccaca2c4933f63c45bf5ffaaa7f2233f2761e3c6ba14a9e5cb82c25`

 It seems to be consistent on Linux, and Mac i have no idea: here's some
 data
 - Mint Cinnamon 32/64bit `not supported`
 - Ubuntu GNOME
 `5abc446cce2558be83bfe60baeb6dc7ff2a17635057c4612fe835649e7c77329`
 - Debian GNOME
 `5abc446cce2558be83bfe60baeb6dc7ff2a17635057c4612fe835649e7c77329`
 - Mac 10.14
 `96f2538daa8a0a180f77a13d80ad455a75ae17c5495ce90fa4fd4267cbfd5210`

 So besides windows OS entropy, theres at least two buckets for Linux?

 [1] https://ghacksuserjs.github.io/TorZillaPrint/TorZillaPrint.html#canvas

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/30537#comment:3>
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