1.\" $NetBSD: pam.8,v 1.5 2015/04/28 09:48:31 prlw1 Exp $ 2.\" 3.\" Copyright (c) 2005 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Jason R. Thorpe. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28.\" POSSIBILITY OF SUCH DAMAGE. 29.\" 30.Dd February 28, 2005 31.Dt PAM 8 32.Os 33.Sh NAME 34.Nm pam 35.Nd Pluggable Authentication Modules framework 36.Sh DESCRIPTION 37The Pluggable Authentication Modules 38.Pq PAM 39framework is a system of libraries that perform authentication tasks for 40services and applications. 41Applications that use the PAM API may have their authentication behavior 42configured by the system administrator through the use of the service's 43PAM configuration file. 44.Pp 45PAM modules provide four classes of functionality: 46.Bl -tag -width password 47.It account 48Account verification services such as password expiration and access control. 49.It auth 50Authentication services. 51This usually takes the form of a challenge-response conversation. 52However, PAM can also support, with appropriate hardware support, biometric 53devices, smart-cards, and so forth. 54.It password 55Password 56.Pq or, more generally, authentication token 57change and update services. 58.It session 59Session management services. 60These are tasks that are performed before access to a service is granted 61and after access to a service is withdrawn. 62These may include updating activity logs or setting up and tearing down 63credential forwarding agents. 64.El 65.Pp 66A primary feature of PAM is the notion of 67.Dq stacking 68different modules together to form a processing chain for the task. 69This allows fairly precise control over how a particular authentication 70task is performed, and under what conditions. 71PAM module configurations may also inherit stacks from other module 72configurations, providing some degree of centralized administration. 73.Sh SEE ALSO 74.Xr login 1 , 75.Xr passwd 1 , 76.Xr su 1 , 77.Xr pam 3 , 78.Xr pam.conf 5 , 79.Xr pam_chroot 8 , 80.Xr pam_deny 8 , 81.Xr pam_echo 8 , 82.Xr pam_exec 8 , 83.Xr pam_ftpusers 8 , 84.Xr pam_group 8 , 85.Xr pam_guest 8 , 86.Xr pam_krb5 8 , 87.Xr pam_ksu 8 , 88.Xr pam_lastlog 8 , 89.Xr pam_login_access 8 , 90.Xr pam_nologin 8 , 91.Xr pam_permit 8 , 92.Xr pam_radius 8 , 93.Xr pam_rhosts 8 , 94.Xr pam_rootok 8 , 95.Xr pam_securetty 8 , 96.Xr pam_self 8 , 97.Xr pam_skey 8 , 98.Xr pam_ssh 8 , 99.Xr pam_unix 8 100.Sh HISTORY 101The Pluggable Authentication Module framework was originally developed 102by SunSoft, described in DCE/OSF-RFC 86.0, and first deployed in Solaris 2.6. 103It was later incorporated into the X/Open Single Sign-On Service 104.Pq XSSO 105Pluggable Authentication Modules specification. 106.Pp 107The Pluggable Authentication Module framework first appeared in 108.Nx 3.0 . 109