heavyboots (@heavyboots@mastodon.social)
mastodon.social
Attached: 2 images Since I’m the idiot learning this by filing bug reports, I thought I’d pass it on to all other #FireFox users on here. If you enable resistFingerprinting in about:config, the web site will start showing you weird stripy graphics anywhere an HTML5 canvas graphic would be generated. To fix this for sites you trust is to click on the tiny graphic icon to the left of the URL and allow use of your HTML5 canvas. Big thanks to the patient Bugzilla guys for dealing with my bug report and the solution.

My apologies to the Bugzilla team for wasting their time holding my hand on this one. Would have honestly never noticed the little “HTML5” info icon to the left of the URL bar though without their help.

  • muntedcrocodile@lemm.eeEnglish
    91·
    3 months ago

    Hmm seems like their would be ways to mitigate this. Why not just introduce some random human undetectable changes to every pixel ie change breightness color alpha etc by 1 or something so every time u call the ToDataURL it returns different data? Might break some things but since canvases dont seem to be predictable systems anyway whats the harm?

    • junepf@lemmy.blahaj.zone
      14·
      3 months ago

      Yes, that is one method to resist canvas fingerprinting, but only resist it. Notice the portion about GPU performance testing, that would work even if the data was fuzzed. The best method seems to be to return fake data that changes frequently, but even that is contested.

      Here’s a good document with other methods (but not focusing on just canvas fingerprinting): https://2019.www.torproject.org/projects/torbrowser/design/#fingerprinting-linkability

      For what it’s worth, Firefox does protect against canvas fingerprinting by default it seems. I am not exactly sure how, however.