centos man page for pam_wheel

PAM_WHEEL(8)							 Linux-PAM Manual						      PAM_WHEEL(8)

NAME
       pam_wheel - Only permit root access to members of group wheel

SYNOPSIS
       pam_wheel.so [debug] [deny] [group=name] [root_only] [trust] [use_uid]

DESCRIPTION
       The pam_wheel PAM module is used to enforce the so-called wheel group. By default it permits root access to the system if the applicant
       user is a member of the wheel group. If no group with this name exist, the module is using the group with the group-ID 0.

OPTIONS
       debug
	   Print debug information.

       deny
	   Reverse the sense of the auth operation: if the user is trying to get UID 0 access and is a member of the wheel group (or the group of
	   the group option), deny access. Conversely, if the user is not in the group, return PAM_IGNORE (unless trust was also specified, in
	   which case we return PAM_SUCCESS).

       group=name
	   Instead of checking the wheel or GID 0 groups, use the name group to perform the authentication.

       root_only
	   The check for wheel membership is done only.

       trust
	   The pam_wheel module will return PAM_SUCCESS instead of PAM_IGNORE if the user is a member of the wheel group (thus with a little play
	   stacking the modules the wheel members may be able to su to root without being prompted for a passwd).

       use_uid
	   The check for wheel membership will be done against the current uid instead of the original one (useful when jumping with su from one
	   account to another for example).

MODULE TYPES PROVIDED
       The auth and account module types are provided.

RETURN VALUES
       PAM_AUTH_ERR
	   Authentication failure.

       PAM_BUF_ERR
	   Memory buffer error.

       PAM_IGNORE
	   The return value should be ignored by PAM dispatch.

       PAM_PERM_DENY
	   Permission denied.

       PAM_SERVICE_ERR
	   Cannot determine the user name.

       PAM_SUCCESS
	   Success.

       PAM_USER_UNKNOWN
	   User not known.

EXAMPLES
       The root account gains access by default (rootok), only wheel members can become root (wheel) but Unix authenticate non-root applicants.

	   su	   auth     sufficient	   pam_rootok.so
	   su	   auth     required	   pam_wheel.so
	   su	   auth     required	   pam_unix.so

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

AUTHOR
       pam_wheel was written by Cristian Gafton <gafton@redhat.com>.

Linux-PAM Manual						    09/19/2013							      PAM_WHEEL(8)