.\"	$NetBSD: pam.8,v 1.5 2015/04/28 09:48:31 prlw1 Exp $
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.\" by Jason R. Thorpe.
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.Dd February 28, 2005
.Dt PAM 8
.Os
.Sh NAME
.Nm pam
.Nd Pluggable Authentication Modules framework
.Sh DESCRIPTION
The Pluggable Authentication Modules
.Pq PAM
framework is a system of libraries that perform authentication tasks for
services and applications.
Applications that use the PAM API may have their authentication behavior
configured by the system administrator through the use of the service's
PAM configuration file.
.Pp
PAM modules provide four classes of functionality:
.Bl -tag -width password
.It account
Account verification services such as password expiration and access control.
.It auth
Authentication services.
This usually takes the form of a challenge-response conversation.
However, PAM can also support, with appropriate hardware support, biometric
devices, smart-cards, and so forth.
.It password
Password
.Pq or, more generally, authentication token
change and update services.
.It session
Session management services.
These are tasks that are performed before access to a service is granted
and after access to a service is withdrawn.
These may include updating activity logs or setting up and tearing down
credential forwarding agents.
.El
.Pp
A primary feature of PAM is the notion of
.Dq stacking
different modules together to form a processing chain for the task.
This allows fairly precise control over how a particular authentication
task is performed, and under what conditions.
PAM module configurations may also inherit stacks from other module
configurations, providing some degree of centralized administration.
.Sh SEE ALSO
.Xr login 1 ,
.Xr passwd 1 ,
.Xr su 1 ,
.Xr pam 3 ,
.Xr pam.conf 5 ,
.Xr pam_chroot 8 ,
.Xr pam_deny 8 ,
.Xr pam_echo 8 ,
.Xr pam_exec 8 ,
.Xr pam_ftpusers 8 ,
.Xr pam_group 8 ,
.Xr pam_guest 8 ,
.Xr pam_krb5 8 ,
.Xr pam_ksu 8 ,
.Xr pam_lastlog 8 ,
.Xr pam_login_access 8 ,
.Xr pam_nologin 8 ,
.Xr pam_permit 8 ,
.Xr pam_radius 8 ,
.Xr pam_rhosts 8 ,
.Xr pam_rootok 8 ,
.Xr pam_securetty 8 ,
.Xr pam_self 8 ,
.Xr pam_skey 8 ,
.Xr pam_ssh 8 ,
.Xr pam_unix 8
.Sh HISTORY
The Pluggable Authentication Module framework was originally developed
by SunSoft, described in DCE/OSF-RFC 86.0, and first deployed in Solaris 2.6.
It was later incorporated into the X/Open Single Sign-On Service
.Pq XSSO
Pluggable Authentication Modules specification.
.Pp
The Pluggable Authentication Module framework first appeared in
.Nx 3.0 .