On 28/05/2010 00:00, C. Gatzemeier wrote:
2) A special case is true: The group is set as the main group of the user (in /etc/passwd) while the user is NOT added to his group in /etc/groups.May pam_umask test this, for umask relaxation?
Just IMHO, this is *exactly* what pam_umask should be doing, rather than comparing if uid==gid. The only valid test for UPG is if the user's primary group is *truly private*. Comparing the numbers doesn't get you that, it's just checking some user creation policy requirement that may or not be secure. Calling getgrgid/getgrnam and checking that the user list is empty is *ensuring* that it's private, at least at the point in time we check (we can't predict the future).
This check would protect against adding other users to UPGs, at least from the POV of not relaxing the umask (it's still a bad idea).
Regards, Roger