Firefox Privacy Script

Install the supplied Firefox preferences, policies, and extensions with per-file ownership tracking and restoration of overwritten files.

Requirements

• Python 3.9 or newer, using only its standard library.
• Firefox or Firefox ESR with a writable native installation directory.
• Close Firefox before installation or restoration. Browser updates should also be idle.
• Use an elevated terminal for installations under protected system directories.

Python is a new runtime prerequisite for the shared installer. The PowerShell and Bash entry points call the same implementation, keeping file ownership and recovery behavior consistent across platforms.

Native Windows, Linux, and macOS layouts are supported by the path resolver. Snap, Flatpak, Microsoft Store, and externally managed browser packages need separate packaging-specific deployment. Select an explicit installation directory when several Firefox installations exist.

Install

Windows, from an elevated PowerShell window:

.\sos-firefoxprivacy.ps1 --firefox-dir 'C:\Program Files\Mozilla Firefox'

Linux, including ESR:

sudo bash ./sos-firefoxprivacy.sh --firefox-dir /usr/lib/firefox-esr

macOS:

sudo bash ./sos-firefoxprivacy.sh --firefox-dir /Applications/Firefox.app/Contents/Resources

Omit --firefox-dir for automatic discovery when exactly one supported installation is present. Add --force to back up and replace conflicting existing configuration files. Every option works through either wrapper or directly through python3 firefox_privacy.py.

The installer recursively copies the payload. Existing files are backed up before replacement. Unrelated files stay in place. A manifest and original copies live in .sos-privacy-state inside the selected installation. Updates retain the first original backup. Keep this directory until restoration is complete.

All platforms use distribution/policies.json and defaults/pref, following Mozilla AutoConfig guidance. AutoConfig files retain LF line endings in Windows checkouts. This version does not import a global org.mozilla.firefox.plist or copy extensions into Firefox's built-in features directory.

Restore

Use the same installation directory:

sudo bash ./sos-firefoxprivacy.sh --uninstall --firefox-dir /usr/lib/firefox-esr

.\sos-firefoxprivacy.ps1 --uninstall --firefox-dir 'C:\Program Files\Mozilla Firefox'

Uninstall restores backed-up files and removes only files recorded as newly installed. It leaves unrelated files and directories alone. Modified installed files or damaged backups stop recovery before file changes. Preserve or reconcile those edits before retrying. There is no force-delete recovery option.

An interrupted operation retains its journal. Inspect the reported failure, preserve the state directory, then retry or uninstall. A lock prevents concurrent operations. After an abrupt process termination, confirm no installer is running before removing the stale .sos-privacy.lock file.

Migration from earlier versions

Earlier installations lack the ownership manifest required for safe automatic recovery. This version refuses to guess which pre-existing files belong to an older installer. Restore an older backup or review those files manually first. Installing over a legacy configuration backs up the legacy state, not factory defaults.

On macOS, review any global Firefox plist created by an older version separately. This installer does not remove unknown global preferences.

Verify browser behavior

After installation, inspect about:policies and about:support, test required websites, and check installed extensions. The bundled preference and extension versions remain unchanged in this repair. File-level tests do not establish current browser compatibility or extension maintenance status.

python3 -m unittest discover -s tests -v

CI exercises Windows, Linux, and macOS file fixtures. Tests cover recursive payloads, original-byte restoration, unrelated extensions, update recovery, malformed manifests, symlinks, damaged backups, and modified files. Use a disposable native Firefox installation for browser-level acceptance before release.