Hi everyone,
I have a Python program (A) that run under a regular user account. (good)
When some events occur in (A) I need to modify my nftables and only the root is allowed to do so.
I’ve come up with 3 ways to do that (if you know other please share) but I don’t which would be the best.
- Make a
sudocall from (A) withfrom subprocess import runbut I will need to store the password ! and I don’t think is possible to keep it encrypted and decrypted when need it (it’s a flaw)
. - Make (A) writing a file with the requests. Create a (B) daemon (that run as root) that check that file every X and do the necessary
. - Make (A) do an IPC ( Linux socket ) to (B) daemon (that run as root) and does the necessary.
I suppose that the solution 2 is less heavy that the 3 ? But if I’m not mistaken it will react also slower ?
Thanks.
🐧
If your command doesn’t change (doesn’t require dynamic input), sudoers file can make specific command+argument run without password required.
https://www.cyberciti.biz/faq/linux-unix-running-sudo-command-without-a-password/ (ctrl+f search “A better solution”)
(You can also use wildcards in sudoers file but with nftables I imagine it’s a big security risk)
- Is the usual solution, but instead of file use unix socket and user/group permissions as auth - the running user has to be part of some group so that the control client (A) can access the control socket of (B) daemon.
Alternatively you could use capabilities:
Thank you very much @taaz
So you say 2 but with
unix socketso it the same as my proposal number 3 ? no ?I’ll check
capabilitiesYeah kinda, unix socket does count as ipc
You could try
pkexecinsted ofsudo. Pkexec pops up the password prompt in a window insted of prompting in the terminal.It’s a good way of solving it. It’s not scriptable though as it requires user-input.
indeed I need it to be scriptable.
Then implement polkit perhaps? https://polkit.pages.freedesktop.org/polkit/polkit-apps.html
Basically the root using bit is handled via polkit. Three unprivileged bit calls the privileged bit via polkit.
Method 2 could use inotify to wake up when the file changes. It wouldn’t have to poll. Method 3 could launch from inetd so it wouldn’t have to always be running if these events are infrequent.
Have you looked into the suid bit? You can set it on the file, then change the script owner to root and it runs in elevated mode: https://linuxhandbook.com/suid-sgid-sticky-bit/
