Only permit root access to members of group wheel
pam_wheel.so [debug] [deny] [group=name] [root_only] [trust]
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.
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).
The auth and account module types are provided.
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.
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
pam.conf(5), pam.d(5), pam(7)
pam_wheel was written by Cristian Gafton <[email protected]>.