PAM configuration file
From Just Solve the File Format Problem
PAM (Pluggable Authentication Modules) is a user authentication and authorization system used on Linux and other Unix systems. Its configuration files are usually found in the /etc/pam.d directory. There is also an /etc/pam.conf file, but it is rarely used.
A PAM configuration file is text-based. Each line specifies a shared library module that is to be used in certain circumstances. The PAM modules are typically found in the directory /lib/security, or /lib/x86_64-linux-gnu/security, or something like that.
