PAM_GROUP(8)                                            Linux-PAM Manual                                            PAM_GROUP(8)



NAME
       pam_group - PAM module for group access

SYNOPSIS
       pam_group.so

DESCRIPTION
       The pam_group PAM module does not authenticate the user, but instead it grants group memberships (in the credential
       setting phase of the authentication module) to the user. Such memberships are based on the service they are applying for.

       By default rules for group memberships are taken from config file /etc/security/group.conf.

       This module's usefulness relies on the file-systems accessible to the user. The point being that once granted the
       membership of a group, the user may attempt to create a setgid binary with a restricted group ownership. Later, when the
       user is not given membership to this group, they can recover group membership with the precompiled binary. The reason
       that the file-systems that the user has access to are so significant, is the fact that when a system is mounted nosuid
       the user is unable to create or execute such a binary file. For this module to provide any level of security, all
       file-systems that the user has write access to should be mounted nosuid.

       The pam_group module functions in parallel with the /etc/group file. If the user is granted any groups based on the
       behavior of this module, they are granted in addition to those entries /etc/group (or equivalent).

OPTIONS
       This module does not recognise any options.

MODULE TYPES PROVIDED
       Only the auth module type is provided.

RETURN VALUES
       PAM_SUCCESS
           group membership was granted.

       PAM_ABORT
           Not all relevant data could be gotten.

       PAM_BUF_ERR
           Memory buffer error.

       PAM_CRED_ERR
           Group membership was not granted.

       PAM_IGNORE

           pam_sm_authenticate was called which does nothing.

       PAM_USER_UNKNOWN
           The user is not known to the system.

FILES
       /etc/security/group.conf
           Default configuration file

SEE ALSO
       group.conf(5), pam.d(5), pam(8).

AUTHORS
       pam_group was written by Andrew G. Morgan <morganATkernel.org>.



Linux-PAM Manual                                           06/16/2009                                               PAM_GROUP(8)