Pluggable authentication module

The Pluggable Authentication Modules (PAM ) is a software library that provides a common programming interface ( API) for authentication services. PAM was developed in 1995 by Vipin Samar and Charlie Lai at Sun Microsystems and has not changed significantly. In 1997, the Open Group published a preliminary specification, called X / Open Single Sign -on Service ( XSSO ). PAM is now on AIX, HP- UX, Solaris, Linux, FreeBSD, NetBSD, Mac OS X and DragonFly BSD available.

Rather than restate the details of authentication in any application, the PAM - API provides a standardized service in the form of modules. In a configuration file can assign the authentication modules of each service for the system administrator, without having to recompile the software that implements these services.

PAM is frequently used in practice for combining a wide range of services such as SSH and FTP server with only one authentication service. This allows central storage of credentials of these services. If the password is changed at the central location, you can register directly with the new, centrally stored, password for all services. Separate password databases for individual services are not necessary.