Skip to content
GitLab
Projects Groups Topics Snippets
  • /
  • Help
    • Help
    • Support
    • Community forum
    • Submit feedback
    • Contribute to GitLab
  • Sign in
  • Trac Trac
  • Project information
    • Project information
    • Activity
    • Labels
    • Members
  • Issues 246
    • Issues 246
    • List
    • Boards
    • Service Desk
    • Milestones
  • Monitor
    • Monitor
    • Incidents
  • Analytics
    • Analytics
    • Value stream
  • Wiki
    • Wiki
  • Activity
  • Create a new issue
  • Issue Boards
Collapse sidebar
  • Legacy
  • TracTrac
  • Issues
  • #6253
Closed
Open
Issue created Jun 28, 2012 by Mike Perry@mikeperry

Prompt before allowing HTML5 Canvas image extraction

The HTML5 canvas can be used for fingerprinting WebGL and font rendering as described in http://www.w2spconf.com/2012/papers/w2sp12-final4.pdf. The fingerprint technique hinges on the ability for JS to extract image/data urls from the canvas object and hash them and/or compute differences. There's some demonstration code that works for a specific (but currently unknown) ruby version here: https://github.com/kmowery/canvas-fingerprinting.

I think the least-effort defense for now is to simply prompt before image extraction, and to allow extraction permissions to be set on a url-bar domain basis if the user has opted to store browser state to disk.

Later, we can think about virtualizing this surface during extraction, but I don't think we'll need to do that unless every site in the world decides to make a lolcat captioning HTML5 widget.

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