14.2. PAM Configuration Files
The directory /etc/pam.d//etc/pam.conf was used, but this
file is now deprecated and pam.conf is only read if
the /etc/pam.d/ directory does not exist.
14.2.1. PAM Service Files
Each PAM-aware application or service has a
file within the /etc/pam.d/ directory. Each of
these files is named after the service for which it controls
access.
/etc/pam.d/
directory. For example, the login program defines
its service name as /etc/pam.d/login.