Shared folder between 2 users?

doffactory

I wonder whether there can be a defined a shared folder between 2 defined users. I know it might go against the whole philosophy of GrapheneOS, but it could be useful in some scenarios, like on certain OSes the /shared folder is shared between users.

MetropleX

doffactory from an OS perspective, no, this is not possible. Each user is treated as a separate device, hence why you may see, if you install Play Services in more than one user, multiple e-mails from Google (if using an account) saying 'Welcome to your new Pixel'.

It's just part of how users are designed, you can read more about them here:

https://source.android.com/docs/devices/admin/multi-user

For a third party solution many recommend Syncthing.

rustybird

File sharing over localhost. Janky to set up, but this combination seems to work:

primitive ftpd (Storage Type: SAF, Server(s) to be started: SFTP only, IP to bind to: 127.0.0.1, Secure Port defaults to 1234) as the server app in one user profile
Material Files as the client app in another user profile

Both apps are available in the main F-Droid repository.

Graphite

Isn't there a back channel set up between user profiles, for Notification Forwarding?

My use case is to share credentials from one user profile with KeePass, to another profile. It'll be very nice if I didn't have to store my KeePass database files globally accessible.

It seems more secure not to deal with files at all (No syncthing), but rather send data using Notification Forwarding, if possible.

unwat

Graphite

I actually looked in to the code for this a while back to see how they forward notifications. It's not a back channel. It's just they added an additional notification channel for Android System, so Android System basically sends the original notification to the destination profile, then another to the active profile.

Is what you proposed possible? Of course. Anything is possible when you can modify the source code at will. Is it possible to achieve without poking holes in profiles' security? Maybe.

I do know that the current setup cannot be changed slightly to send over short bits of text for copying and pasting because you can't copy from notifications (that I know of).

And since the thread is about this, no, sending files this way won't work. If they did do that, the file size would be very limited, something like <5 MB.

LoyyWeber42

Hi, you can read in the manual about shared external folders.
https://grapheneos.org/usage
There, at "There are two types of app-accessible storage:"
How can you unterstand "shared with other apps"?
Is this not the solution, we are searching for?
Loy

Graphite

LoyyWeber42

This is not a solution.
User profiles have completely separate encrypted filesystems.
The "shared storage" in the usage manual refers only to within a single user profile.

Graphite

I wound up using an app called Material Files. It has an FTP server and client. The server doesn't do encryption, but I can start it manually when I need to transfer.

For sharing the clipboard, I wound up creating an app from Tasker app factory. Very simple automation that uses the built-in netcat to create a listener server that will pipe in clipboard text and then you switch user profiles, and run another netcat which retrieves the text.

LoyyWeber42

Thanks!