Skip to content
GitLab
Projects Groups Snippets
  • /
  • Help
    • Help
    • Support
    • Community forum
    • Submit feedback
    • Contribute to GitLab
  • Sign in
  • Tor Browser Tor Browser
  • Project information
    • Project information
    • Activity
    • Labels
    • Members
  • Repository
    • Repository
    • Files
    • Commits
    • Branches
    • Tags
    • Contributors
    • Graph
    • Compare
  • Issues 830
    • Issues 830
    • List
    • Boards
    • Service Desk
    • Milestones
  • Merge requests 5
    • Merge requests 5
  • Deployments
    • Deployments
    • Releases
  • Monitor
    • Monitor
    • Incidents
  • Analytics
    • Analytics
    • Value stream
    • Repository
  • Wiki
    • Wiki
  • Activity
  • Graph
  • Create a new issue
  • Commits
  • Issue Boards
Collapse sidebar
  • The Tor Project
  • Applications
  • Tor BrowserTor Browser
  • Issues
  • #30531
Closed
Open
Issue created May 18, 2019 by intrigeri@intrigeri

WebGL antialiasing support enabled iff. OpenGL is supported

With Tor Browser 8.5-build2, we see 2 different WebGL fingerprints on panopticlick: 2ef68bcd75e09a41aea04bae556f3ecc on bare metal and in VMs that support OpenGL acceleration, f9a0f737691a9b57f5294121fc58a2df in VMs that don't support OpenGL acceleration.

Quoting segfault (from https://redmine.tails.boum.org/code/issues/16337#note-61) who investigated this further:

"I looked at the JS code used by panopticlick to calculate this hash, and printed the values which go into the hash. The only difference I could find is that antialiasing is enabled iff OpenGL is enabled. (That's exposed via the antialias bool of gl.getContextAttributes(), see https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/getContextAttributes)."

Impact: 1 bit of fingerprinting; risk: nowadays I would assume the huge majority of bare metal systems that can run TB have OpenGL, but most VMs haven't (unless geeky configuration is done, which is a minority). So it's roughly equivalent to splitting the anonymity set between VMs and bare metal, I'd say.

GeKo says:

i guess we could think about making the antialiasing info uniform like, just saying "no"

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information
Assignee
Assign to
Time tracking