Privacy Preserving Attribution - Githubissues

arkenfox / TZP

TorZillaPrint: Firefox & Tor Browser fingerprint testing

https://arkenfox.github.io/TZP

MIT License

194 stars 27 forks source link

Privacy Preserving Attribution #319

Closed sertonix closed 2 months ago

sertonix commented 2 months ago

When PPA is disabled the functions are a no-op. This skips the argument checking too so it is possible to detect whenever or not PPA is enabled. From what I have seen it should be possible to hide whenever PPA is enabled or disabled.

let enabled = false;
try {
  // The ~ is considered an invalid url and will cause an error when PPA is enabled.
  navigator.privateAttribution.saveImpression({ type: "view", index: 6, ad: "shoes", target: "~" });
} catch (e) {
  if (e instanceof DOMException)
    enabled = true;
}

Since PPA is an Origin Trial you currently need to set dom.origin-trials.private-attribution.state: 1 for the API to be available on any website.

Thorin-Oakenpants commented 2 months ago

AFAICT ... when this becomes available on any website ... this is not a thing

see https://github.com/mozilla/explainers/issues/11#issuecomment-2228913120
The API appears to function fully when someone is opted out, but no private information is released. That is, saveImpression appears to save something (but saves nothing), and measureConversion generates a measurement message that contains all zero values. From the perspective of the sites involved, things appear to be exactly the same as someone who has the feature enabled.

sertonix commented 2 months ago

Then this is a bug in firefox. Made a report here https://bugzilla.mozilla.org/show_bug.cgi?id=1908470

Thorin-Oakenpants commented 2 months ago

sorry, I have a lot going on and am not really following this

Thorin-Oakenpants commented 2 months ago

I honestly can't quite follow this - I tried the other day in nightly with it enabled and not enabled and couldn't detect a difference (using console on live web sites)

edit: OK I needed to flip the pref for all sites? right?

sertonix commented 2 months ago

Setting dom.origin-trials.private-attribution.state to 1 enables the API for all sites. This is needed cause the API is experimental (and the other options are too complicated).

Thorin-Oakenpants commented 2 months ago

okie dokie - soz, am super busy with TB stuff - ESR128 is a huge jump :)

Thorin-Oakenpants commented 2 months ago

ok, so being a Origin Trial (OT) this currently doesn't make a viable FP as it's not universal. And once 1908470 is fixed then when OT becomes obsolete (i.e enabled universally?) it's no longer a FP vector. So closing. But good catch