I would build a great sandbox. And nobody builds sandboxes better than me, believe me. I will build a great, great sandbox on our application border. And I will have Tor Browser pay for that sandbox.
Tor Browser sandboxed somewhat correctly using bubblewrap. Obviously only works on Linux, and will NEVER support anything else since sandboxing is OS specific.
There are several unresolved issues that affect security and fingerprinting. Do not assume that this is perfect, merely "an improvement over nothing".
Runtime dependencies:
- A modern Linux system on x86_64 architecture.
- bubblewrap >= 0.1.3 (https://github.com/projectatomic/bubblewrap).
- Gtk+ >= 3.14.0
- (Optional) PulseAudio
- (Optional) Adwaita Gtk+-2.0 theme
- (Optional) libnotify and a Desktop Notification daemon
Build time dependencies:
- Make
- A C compiler
- gb (https://getgb.io/ Yes I know it's behind fucking cloudflare)
- Go (Tested with 1.7.x)
- libnotify
Things that the sandbox breaks:
- Audio (Unless allowed via the config)
- DRI
- X11 input methods (IBus requires access to the host D-Bus)
- Installing addons (Addons are whitelisted)
- Tor Browser's updater (launcher handles keeping the bundle up to date)
Places where the sandbox could be better:
- The updater container still mounts
/proc. - PulseAudio is likely unsafe without a protocol filter like X11.
- X11 is still X11, and despite mitigations is likely still unsafe.
Upstream Bugs:
- Tor Browser should run without a
/procfilesystem, worked around in the worst possible way. (https://bugs.torproject.org/20283) - OpenGL software rendering is broken on certain Linux systems. (https://bugs.torproject.org/20866)
Notes:
- Follows the XDG Base Dir specification.
- Questions that could be answered by reading the code will be ignored.
- Unless you're capable of debugging it, don't use it, and don't contact me about it.
- By default the sandbox
~/Desktopand~/Downloadsdirectories are mapped to the host~/.local/share/sandboxed-tor-browser/tor-browser/Browser/[Desktop,Downloads]directories. - https://git.schwanenlied.me/yawning/sandboxed-tor-browser/wiki has something resembling build instructions, that may or may not be up to date.