pam_localuser - require users to be listed in /etc/passwd

       pam_localuser was written by Nalin Dahyabhai <nalin@redhat.com>.

Linux-PAM                                          07/03/2025                                   PAM_LOCALUSER(8)

       pam_localuser is a PAM module to help implementing site-wide login policies, where they typically include
       a subset of the network's users and a few accounts that are local to a particular workstation. Using
       pam_localuser and pam_wheel or pam_listfile is an effective way to restrict access to either local users
       and/or a subset of the network's users.

       This could also be implemented using pam_listfile.so and a very short awk script invoked by cron, but
       it's common enough to have been separated out.

       Add the following lines to /etc/pam.d/su to allow only local users or group wheel to use su.

           account sufficient pam_localuser.so
           account required pam_wheel.so

/etc/passwd
           Local user account information.

       All module types (account, auth, password and session) are provided.

       pam_localuser - require users to be listed in /etc/passwd

       debug
           Print debug information.

       file=/path/passwd
           Use a file other than /etc/passwd.

       PAM_SUCCESS
           The new localuser was set successfully.

       PAM_BUF_ERR
           Memory buffer error.

       PAM_CONV_ERR
           The conversation method supplied by the application failed to obtain the username.

       PAM_INCOMPLETE
           The conversation method supplied by the application returned PAM_CONV_AGAIN.

       PAM_SERVICE_ERR
           The user name is not valid or the passwd file is unavailable.

       PAM_PERM_DENIED
           The user is not listed in the passwd file.

pam.conf(5), pam.d(5), pam(7)

pam_localuser.so [debug] [file=/path/passwd]