- Programs that grant users access to a system use authentication to verify each other's identity (that is, to establish that a user is who they say they are).
- The problem is that every time a new authentication scheme is developed, it requires all necessary programs to be rewritten to support it. PAM provides ay to develop programs that are independent of authentication scheme.
/etc/pam.d/contains all PAM configuration files.- Linux-PAM deals with four separate types of (management) task.
- authentication management
- account management
- session management
- password management.
- The association of the preferred management scheme with the behavior of an application is made with entries in the relevant Linux-PAM configuration file. The management functions are performed by modules specified in the configuration file.
The format of each rule is a space separated collection of tokens, the first three being case-insensitive:
type control module-path module-arguments