Fingerprinting Protections v2: Workers - WebGL Drawing - follow up to 11368, 11839

[LaurenWags]

Description

Found while testing #11368, #11839

Per discussion with @pes10k, assigning to @pilgrim-brave for investigation.

Per instructions on dev-pages.brave.software/farbling.html and dev-pages.bravesoftware.com/farbling.html, for WebGL Drawing the "Worker" column value should match the other columns for that row when FP = standard (since Mode only has standard, not both, for this row) and the value should be different between the two pages.

Additionally, if FP = strict, this is working. This is unexpected since mode = standard for WebGL Drawing. @pes10k @pilgrim-brave could you guys help clear this up? Does WebGL Drawing farbling work for both std and strict?

Steps to Reproduce

1. Clean profile, 1.16.x
2. Navigate to dev-pages.brave.software/farbling.html and dev-pages.bravesoftware.com/farbling.html
3. Confirm FP = standard
4. Generate Fingerprints

Actual result:

For WebGL Drawing the "Worker" column value does not match the others for that row when FP = standard.

FP = standard

FP = strict

Expected result:

For WebGL Drawing the "Worker" column value should match the others for that row when FP = standard.

Reproduces how often:

easily

Desktop Brave version:

Brave	1.16.58 Chromium: 86.0.4240.75 (Official Build) dev (x86_64)
Revision	c69c33933bfc72a159aceb4aeca939eb0087416c-refs/branch-heads/4240@{#1149}
OS	macOS Version 10.14.6 (Build 18G3020)

Android Device details:

• Install type (ARM, x86):
• Device type (Phone, Tablet, Phablet):
• Android version:

Version/Channel Information:

• Can you reproduce this issue with the current release? n/a
• Can you reproduce this issue with the beta channel? yes 1.16.x
• Can you reproduce this issue with the nightly channel? yes 1.17.x

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information:

cc @rebron

[LaurenWags]

Reproduces in 1.17.x as well:

FP = standard

FP = strict

[pes10k]

Similarly, I think this is fixed now and ready for a re-check when you have a chance @LaurenWags. Thanks!

[LaurenWags]

@pes10k what version do you think this should be checked against - Nightly (currently 1.21.x) or one of the other channels?

[pes10k]

Ah, sorry @LaurenWags ! It should be fixed in nightly / 1.21.x

[LaurenWags]

@pes10k hm, using the below build I don't get any vaules for WebGL Drawing (or several others for that matter). Is this expected? This is a clean profile btw.

Brave | 1.21.44 Chromium: 88.0.4324.146 (Official Build) beta (x86_64)
-- | --
Revision | 406dc88511162d6598242f2c709be1414a042fb0-refs/branch-heads/4324@{#2088}
OS | macOS Version 10.15.7 (Build 19H15)

Example	Example

[pes10k]

Ah, apologies @LaurenWags , i was working on the page at the same time you were testing it, sorry for the hassle! Should be good now :)

[LaurenWags]

@pes10k looks like I can still reproduce using a clean profile (default shields, never touched) and the below build:

Brave | 1.21.47 Chromium: 88.0.4324.152 (Official Build) beta (x86_64)
-- | --
Revision | 6579930fc53b4dc589c042bec9d0a3778326974d-refs/branch-heads/4324@{#2106}
OS | macOS Version 10.15.7 (Build 19H512)

Example	Example

[pes10k]

Closing because, same as #12099, this is not a bug, but needing to use different Web APIs to farble in workers, and so the fabling happening at a different intervention point