I don't really see the interest of putting a password on my PC to reboot or shutdown it. Just because if a guy really wants to shutdown my PC he can easily unplug the cable and it's not the password that will stop him
So i tried to put a rule into sudo like this:
gdm = NOPASSWD: /sbin/halt, /sbin/shutdown, /sbin/reboot
But, as i thought, it didn't change anything (it seems normal to me because no one tells him to execute "sudo /sbin/reboot"
So, did someone succeed in doing it without giving suid privilege to the programs ? Which is here quite dangerous, i don't want that a guy can reboot my PC from ssh
Thanks a lot for the future answers !