systemd-homed: Change group membership without root and user passwords

[eric <eric@xxxxxxxxxxxxx>]

Hey everyone on systemd-devel

Is there somehow a method to change group membership without having the 
user's password ?

Usually its an admin task to maintain group membership and she has no 
user passwords.

But when its the users task to join a group, the user needs the admin 
password, this is also a bad situation.

Is it possible to add more than one password ?

/eric