PAM is a generic framework, which is implemented on different operating systems. The typical operating systems are similar to UNIX including Linux, FreeBSD, and Solaris. Each implementation varies for each operating system, but a common set of modules can be found in all. Furthermore, many modules are portable, and can easily be installed from source.
A set of basic parameters used by most modules are the same. Moreover, these basic parameters are independent of the operating system. The parameters are typically used to control the amount of debug information and reuse of passwords.
This chapter presents the common parameters and modules of PAM. Using common modules unifies the various UNIX operating systems, and you as system administrator will be more robust against changing UNIX platforms.