The PAM framework enables you to configure the use of system entry services (such as, ftp, login, telnet, or rsh) for user authentication. Some benefits that PAM provides are as follows:
Flexible configuration policy
Per-application authentication policy
The ability to choose a default authentication mechanism
The ability to require multiple authorizations on high-security systems
Ease of use for the end user
No retyping of passwords if the passwords are the same for different authentication services
The ability to prompt the user for passwords for multiple authentication services without requiring the user to type multiple commands
The ability to pass optional options to the user authentication services
The ability to implement a site-specific security policy without having to change the system entry services