Visit Our UNIX and Linux User Community

Linux and UNIX Man Pages

Test Your Knowledge in Computers #443
Difficulty: Easy
FHM, a men's lifestyle magazine, asked 1,344 women if they preferred to hang out with a computer science expert or a footballer, and 1,023 (76.116%) stated they preferred geeks over athletes.
True or False?
Linux & Unix Commands - Search Man Pages

pam(8) [netbsd man page]

PAM(8)							    BSD System Manager's Manual 						    PAM(8)

pam -- Pluggable Authentication Modules framework DESCRIPTION
The Pluggable Authentication Modules (PAM) framework is a system of libraries that perform authentication tasks for services and applica- tions. Applications that use the PAM API may have their authentication behavior configured by the system administrator though the use of the service's PAM configuration file. PAM modules provide four classes of functionality: account Account verification services such as password expiration and access control. 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. password Password (or, more generally, authentication token) change and update services. session Session management services. These are tasks that are performed before access to a service is granted and after access to a ser- vice is withdrawn. These may include updating activity logs or setting up and tearing down credential forwarding agents. A primary feature of PAM is the notion of ``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. SEE ALSO
login(1), passwd(1), su(1), pam(3), pam.conf(5), pam_chroot(8), pam_deny(8), pam_echo(8), pam_exec(8), pam_ftpusers(8), pam_group(8), pam_guest(8), pam_krb5(8), pam_ksu(8), pam_lastlog(8), pam_login_access(8), pam_nologin(8), pam_permit(8), pam_radius(8), pam_rhosts(8), pam_rootok(8), pam_securetty(8), pam_self(8), pam_skey(8), pam_ssh(8), pam_unix(8) 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 (XSSO) Pluggable Authentication Modules specifiation. The Pluggable Authentication Module framework first appeared in NetBSD 3.0. BSD
February 28, 2005 BSD

Check Out this Related Man Page

PAM(7)								 Linux-PAM Manual							    PAM(7)

PAM, pam - Pluggable Authentication Modules for Linux DESCRIPTION
This manual is intended to offer a quick introduction to Linux-PAM. For more information the reader is directed to the Linux-PAM system administrators' guide. Linux-PAM is a system of libraries that handle the authentication tasks of applications (services) on the system. The library provides a stable general interface (Application Programming Interface - API) that privilege granting programs (such as login(1) and su(1)) defer to to perform standard authentication tasks. The principal feature of the PAM approach is that the nature of the authentication is dynamically configurable. In other words, the system administrator is free to choose how individual service-providing applications will authenticate users. This dynamic configuration is set by the contents of the single Linux-PAM configuration file /etc/pam.conf. Alternatively, the configuration can be set by individual configuration files located in the /etc/pam.d/ directory. The presence of this directory will cause Linux-PAM to ignore /etc/pam.conf. From the point of view of the system administrator, for whom this manual is provided, it is not of primary importance to understand the internal behavior of the Linux-PAM library. The important point to recognize is that the configuration file(s) define the connection between applications (services) and the pluggable authentication modules (PAMs) that perform the actual authentication tasks. Linux-PAM separates the tasks of authentication into four independent management groups: account management; authentication management; password management; and session management. (We highlight the abbreviations used for these groups in the configuration file.) Simply put, these groups take care of different aspects of a typical user's request for a restricted service: account - provide account verification types of service: has the user's password expired?; is this user permitted access to the requested service? authentication - authenticate a user and set up user credentials. Typically this is via some challenge-response request that the user must satisfy: if you are who you claim to be please enter your password. Not all authentications are of this type, there exist hardware based authentication schemes (such as the use of smart-cards and biometric devices), with suitable modules, these may be substituted seamlessly for more standard approaches to authentication - such is the flexibility of Linux-PAM. password - this group's responsibility is the task of updating authentication mechanisms. Typically, such services are strongly coupled to those of the auth group. Some authentication mechanisms lend themselves well to being updated with such a function. Standard UN*X password-based access is the obvious example: please enter a replacement password. session - this group of tasks cover things that should be done prior to a service being given and after it is withdrawn. Such tasks include the maintenance of audit trails and the mounting of the user's home directory. The session management group is important as it provides both an opening and closing hook for modules to affect the services available to a user. FILES
/etc/pam.conf the configuration file /etc/pam.d the Linux-PAM configuration directory. Generally, if this directory is present, the /etc/pam.conf file is ignored. ERRORS
Typically errors generated by the Linux-PAM system of libraries, will be written to syslog(3). CONFORMING TO
DCE-RFC 86.0, October 1995. Contains additional features, but remains backwardly compatible with this RFC. SEE ALSO
pam(3), pam_authenticate(3), pam_sm_setcred(3), pam_strerror(3), PAM(7) Linux-PAM Manual 06/04/2011 PAM(7)

Featured Tech Videos