Broken sites from WebWorker protection on Firefox

[brochard]

Summary

I realised most broken sites I have is caused by the WebWorker protection so I gathered a list here and the level at which it works with no problem.

Setup

Pages affected:

• Cryptpad (https://cryptpad.fr/drive/), works when WebWorker is set to Medium
• Twitch video player (https://www.twitch.tv/) // Unprotected
• Proton Mail/Calendar/Drive (https://mail.proton.me/ + https://calendar.proton.me/ + https://drive.proton.me/) // Unprotected
• Element (https://app.element.io/) works very slowly on Medium, works well on Unprotected
• Recaptcha sites (examples https://www.omgserv.com/fr/connexion/ + https://patrickhlauke.github.io/recaptcha/) // Unprotected
• Overleaf compiling to pdf (https://www.overleaf.com/) // Unprotected
• Gitlab difs (not on main instance, for example https://gitlab.redox-os.org/redox-os/presentations/-/merge_requests/1/diffs) // Unprotected

JShelter Version: 0.11.2

Popup information (open JShelter popup on affected pages:

JavaScript Shield ON
Network Boundary Shield ON
Fingerprint Detector ON
Level: Recommanded

[Optional:]

OS: Windows 10
Browser: Firefox
Other extensions that might affect JShelter behaviour: Ublock Origin

How to reproduce

1. Open site
2. For overleaf only : connect to an account, create a document and see if it compiles on the right

Expected result

Site loading / Videos loading / pdf compiling / Captcha completing

Actual result

not loading

Reproducibility

Tested it with another clean Firefox Nightly and Brave

-> They're all broken on both instance of Firefox
-> None of those sites are broken one Brave

Workarounds

I gave the necessary WebWorker level for each of these

[polcak]

Thank you. I added a link to this issue to https://pagure.io/JShelter/webextension/issue/80. I will close this one as a duplicate of the Pagure issue. If you have further comments, feel free to post here.

As posted in #199, I am not sure that we will try to fix this in MV2, we will try for MV3.

[polcak]

Hello @brochard,

once again, thank you for the list. I am now testing with the recently released 0.12.1 in Firefox.

Cryptpad (https://cryptpad.fr/drive/) works with all WebWorker policies,
Proton does not work
Element (https://app.element.io/) works but not sure if that is slowly or not
Gitlab diffing still broken

Firefox Low policy should be fixed, hopefully soon.

See FAQ. Currently, we are not aware of a reliable and safe way that can insert polyfills for the pages. Some pages insert their own polyfills and work others do not. So we changed the Strict policy to break Workers and added Remove policy. Those can potentially work or we leave the decision on users.

Still, the preferred solution is to inject polyfills so if there is a new API that would allow us to do so or we discover a reliable and safe way with current APIs, we might improve other sites.

[brochard]

Thank you for keeping us updated @polcak
(For element if it doesn't take 30seconds to load then it's not slow)