Bug 42163: Make the DLL blocklist obey portable mode (std::filesystem version)

Merge Info

Related Issues

• #42163 (closed)
• mullvad-browser#xxxxx
• tor-browser-build#xxxxx

Backporting

Timeline

• Immediate: patchset needed as soon as possible
• Next Minor Stable Release: patchset that needs to be verified in nightly before backport
• Eventually: patchset that needs to be verified in alpha before backport
• No Backport (preferred): patchset for the next major stable

You choose, both works for me.

(Optional) Justification

• Emergency security update: patchset fixes CVEs, 0-days, etc
• Censorship event: patchset enables censorship circumvention
• Critical bug-fix: patchset fixes a bug in core-functionality
• Consistency: patchset which would make development easier if it were in both the alpha and release branches; developer tools, build system changes, etc
• Sponsor required: patchset required for sponsor
• Localization: typos and other localization changes that should be also in the release branch
• Other: sort of disk leak, but I don't think many users use this feature. Also, requires the backport of tor-browser-build#41015 (closed)

Merging

• Merge to tor-browser - !fixups to tor-browser-specific commits, new features, security backports
• Merge to base-browser - !fixups to base-browser-specific commits, new features to be shared with mullvad-browser, and security backports
  • NOTE: if your changeset includes patches to both base-browser and tor-browser please clearly label in the change description which commits should be cherry-picked to base-browser after merging

Issue Tracking

• Link resolved issues with appropriate Release Prep issue for changelog generation

Review

Request Reviewer

• Request review from an applications developer depending on modified system:
  • NOTE: if the MR modifies multiple areas, please /cc all the relevant reviewers (since gitlab only allows 1 reviewer)
  • accessibility : henry
  • android : clairehurst, dan
  • build system : boklm
  • extensions : ma1
  • firefox internals (XUL/JS/XPCOM) : ma1
  • fonts : pierov
  • frontend (implementation) : henry
  • frontend (review) : donuts, richard
  • localization : henry, pierov
  • macos : clairehurst, dan
  • nightly builds : boklm
  • rebases/release-prep : dan, ma1, pierov, richard
  • security : ma1
  • signing : boklm, richard
  • updater : pierov
  • misc/other : pierov, richard

Change Description

Supersedes !829 (closed).

In this new version, we use Mozilla's facilities to get the full path to firefox.exe and then we use std::filesystem for path manipulation, that works with paths longer than MAX_PATH also on Windows 7.

For the rest, see the previous MR.

How Tested

Local dev build, I followed the same testing of the previous MR:

• Go to about:third-party, click the button to enable system data (it might take a while to appear) and block a DLL. Restart the browser and check that the DLL stays disabled (the symbol in the button is a cross in a red circle, and the tooltip tells you it's currently disabled). Notice that Browser\TorBrowser\Data\Browser\blocklist has been created.
• Close the browser, delete Browser\TorBrowser\Data\Browser\blocklist, go to about:third-party again and notice the DLL has been unblocked
• Check that HKEY_CURRENT_USER\Software\Tor Project\Firefox\Launcher doesn't have the blocklist entry for this installation of Tor Browser (you can compare with other 13.0aX installs)