/etc/pam.d/ directory contains the PAM configuration files for each PAM-aware application. In earlier versions of PAM, the
/etc/pam.conf file was used, but this file is now deprecated and is only used if the
/etc/pam.d/ directory does not exist.
18.104.22.168. PAM Service Files
Each PAM-aware application or service has a file in the
/etc/pam.d/ directory. Each file in this directory has the same name as the service to which it controls access.
The PAM-aware program is responsible for defining its service name and installing its own PAM configuration file in the
/etc/pam.d/ directory. For example, the
login program defines its service name as
login and installs the
/etc/pam.d/login PAM configuration file.