[iOS 17] Fingerprinting is broken and showing the same values on both pages and after relaunching Brave when Shields enabled

[hffvld]

Description:

[iOS 17] Fingerprinting is broken and showing the same values on both pages and after relaunching Brave when Shields enabled

Steps to Reproduce

1. Launch Brave
2. Go to https://dev-pages.brave.software/fingerprinting/farbling.html
3. Make sure Brave Shields is enabled > Generate fingerprints
4. Check results for Plugins, Hardware connectivity and Speech voices`
5. For each separate feature the value must be the same in every column, but different for each feature
6. Close and relaunch Brave > Run the test again
7. Compare values with results in the previous step > Observe that values are the same
8. Open another page https://dev-pages.bravesoftware.com/fingerprinting/farbling.html
9. Run the test and compare results > Observe that values are the same

Note: Hardware concurrency is hit or miss. We farble number of cores between 2-8 (on iOS 14 and can be less on older devices). With such a low variety of numbers, it's possible that both both test pages get the same value. This can be seen by killing the app and relaunching it. A new random value is given to the farbler and you will see the same values repeating on average 1/7 times as there are only 1/7 possible values we can use.

Actual result:

When Brave Shields is enabled on a device with iOS 17 the values for farbling tests are the same. On iPad with iPadOS 16.5.1 the values are different as expected, so I believe this is iOS 17 specific issue.

1	2	3	4

Expected result:

Results must have different values for farbling tests.

Reproduces how often: [Easily reproduced, Intermittent Issue]

Easily reproduced

Brave Version:

Brave build: 1.57 (23.9.1.15)
BraveCore: 1.57.53 (116.0.5845.114)

• Can you reproduce this issue with the most recent build from TestFlight? Yes
• Can you reproduce this issue with the previous version of the current build from TestFlight? Yes
• Can you reproduce this issue with the current build from AppStore? Yes

Device details:

iPhone 14 [iOS 17.0]

Website problems only:

• did you check with Brave Shields down?
• did you check in Safari/Firefox (WkWebView-based browsers)?

Additional Information

[Uni-verse]

Verified on iPad (7th Gen) running iPadOS 17.0 using version 1.57.1 (23.9.18.13)

• Verified generated values are different for the features using STR in [iOS 17] Fingerprinting is broken and showing the same values on both pages and after relaunching Brave when Shields enabled #8019 (comment).
• Verified farbling test passes on staging and dev test sites.

Test 1	Test 2

[hffvld]

Verified on iPhone 14using version(s):

Device/OS: iPhone 14 [iOS 17.0]
Brave build: 1.57.1 (23.9.20.7)
BraveCore: 1.57.53 (116.0.5845.114)

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Shileds ON

STEPS:
Followed the steps from #8019 (comment)

ACTUAL RESULTS:

• Verified that the results have different values for farbling tests.

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Shileds OFF

STEPS:
Followed the steps from #8019 (comment) but this time wit hShileds OFF

ACTUAL RESULTS:

• Verified that no regression appeared and results have the same values for farbling tests.

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