Firefox default setting in Qubes OS

[whoami]

With the default Qubes settings each new AppVM starts Firefox with its default setting (search “Google”, homepage … no addons … theme…). I looking for a solution to customize the default Firefox setting so that each new AppVM with Firefox has a customized / personalized setting. Is there there a solution within the template VM or an easy export/import approach for all the Firefox settings?

[fsflover]

DisposableVM Customization

[unman]

@whoami - if you want NON disposable qubes to be so configured, then you
can do this:
Open firefox and configure it as you will, (in a normal qube).
qvm-copy .mozilla to a template.
In the template, move the .mozilla folder in to /etc/skel

Now every new qube that uses that template will inherit the .mozilla
folder, and the configuration you have set.
This wont work for existing qubes, but it’s a start.
For existing qubes you could try copying the .mozilla folder to ~.

Obviously you wont want to do this where you want qubes to have a
distinct persona.

[enmus]

Beside useful @unman’s tip, I’m thinking on how to set this for disposableVM, for any browser.

1. Download, not install, all the desired addons to a spare place.
2. Set browsing dvm-template's netVM temporarily to none
3. Open browser in offline mode in a disposableVM.
4. Copy and install all the addons.
5. Set the other browser’s settings as desired.
6. Just in case clear whole cache.
7. Finally, copy such set browser’s profile to a template's /etc/skel/
8. Create completely new `dvm-template’ (see @unman’s post above why)
9. Set netVM to dvm-template if not automatically assigned.
10. Start fully set browser with a clean profile in a new online disposableVM.

This way, it works.

Since I’m using split-browser, relaunching is not an option, like it would be in the regular browsing disposables (I could just start disposable by first starting terminal then Brave and I could relaunch it then), so any idea @rustybird or anyone else could have on how to overcome this with split-browser would be great.

[rustybird]

Why even go through a DisposableVM? I’d just customize Firefox in the -dvm (starting it as an AppVM with network access - or without network access if you’ve already downloaded the addons in another VM). Hmm it does make sense if you’re planning to also use the -dvm for other programs that an exploited Firefox shouldn’t contaminate.

@enmus

I have to say that I tried this with Brave browser (not yet with Firefox), but it complained that the profile was “ used on another machine - dispxxx, so if I want to use it, I have to unlock it first and then to relaunch the browser ”.

This can be avoided by shutting down Brave/Firefox before you copy its profile. (Copying a browser’s profile while it’s still running can also result in data corruption in the copy.)

In case you’re launching the “installation DisposableVM” via Split Browser too: When you’re done customizing Firefox, open a terminal in the same disp1234 and run killall -s STOP split-browser-disp so that the DisposableVM stays alive after Firefox shutdown, and you then have time to copy out the profile.

[enmus]

@rustybird

When you’re done customizing Firefox, open a terminal in the same disp1234 and run killall -s STOP split-browser-disp so that the DisposableVM stays alive after Firefox shutdown, and you then have time to copy out the profile.

Great tip and thanks for it!

@rustybird

Hmm it does make sense if you’re planning to also use the -dvm for other programs that an exploited Firefox shouldn’t contaminate

Well, actually, I use dvm-template only for a single browser, for each browser another dvm-template and no other use. As compartmentalized as possible - just not running anything in what has in its name - template.

@enmus

Finally, copy such set browser’s profile to it’s dvm-template to /rw/home/user or, depending on the browser at the appropriate place in a /rw of a dvm-template .

Unfortunately, this won’t work. No matter what you try with/in dvm-template, a new random profile will be generated in disposableVM conflicting with formerly set profile - “Firefox cannot start, because another instance is already running, blah, blah…”

@unman

qvm-copy .mozilla to a template.
In the template, move the .mozilla folder in to /etc/skel

Fortunately, this works, so I’m not sure why @unman wrote

@unman

if you want NON disposable qubes to be so configured, then you
can do this

Any way, I edited my previous post so it could be relevant.

@unman

Obviously you wont want to do this where you want qubes to have a
distinct persona.

Since I’m using non-TorBrowsers exclusively on clearnet, I don’t find this relevant for my use case, but other might keep it on their mind.

And the most important thing (inserted in edit, too)

@unman

This wont work for existing qubes, but it’s a start.

And definitely

@unman

For existing qubes you could try copying the .mozilla folder to ~.

… this didn’t work for me, but if someone has some tip on this, it would be appreciated.

[unman]

@unman

For existing qubes you could try copying the .mozilla folder to ~.

… this didn’t work for me, but if someone has some tip on this, it would be appreciated.

qubeA:
Check which firefox profile you are using - in firefox type
about:profiles in address bar.
You will see the name of the profile in use: remember it.
Close down firefox.
qvm-copy the .mozilla folder to qubeB

qubeB:
Open terminal.
Delete the .mozilla folder - rm -rf ~/.mozilla
mv ~/QubesIncoming/qubeA/.mozilla ~
Start firefox using the ProfileManager:
firefox --ProfileManager
Select the profile you used in qubeA
Select option to open without prompting in future.

Done

[enmus]

Thanks, I was focused on disposables, and totally forgot the switch at the moment. Right after the post, I did it simply overwriting the content of the default profile firefox folder with the content of the customized one.

[enmus]

A tip to add custom search engine in offline browser:

1. Provide yourself with the search URL in online Firefox and replace search term with %s
2. In an offline Firefox, go to about:config and add new boolean value

browser.urlbar.update2.engineAliasRefresh

3. Go to Settings->Search section of your offline Firefox and there you should get Add button to add new search engine from 1.

[imme-emosol]

i was interested in how to do it for ‘all’ users that start firefox, system-wide.

if i understand correctly, that seems to be possible in /etc/firefox/user.js .

relted links:

Customizing Firefox Using AutoConfig | Firefox for Enterprise Help

policy-templates

https://wiki.archlinux.org/title/Firefox/Privacy

Which files can be used to configure Firefox on Linux Mint 21, where are they stored and when do you use which of these files?

[tempmail]

@imme-emosol

that seems to be possible in /etc/firefox/user.js

If you take that route, maybe this would be interesting to you:

[Guide] Automatically install extensions and configure new (dispvm) hardened Firefox profiles with arkenfox user.js and policies

This was inspired by a number of posts that sometimes pop up on the forum. Section 1 explains how to use arkenfox’s (but you can use any other) user.js file (GitHub - arkenfox/user.js: Firefox privacy, security and anti-tracking: a comprehensive user.js template for configuration and hardening) and make it compatible with Firefox autoconfig, in order to automatically configure new dispvm (or appvm) profiles without first creating one (so no profile-name fingerprinting). For more information, s…