pam_shells

pam_shells.so

pam_shells is a PAM module that only allows access to the system if the user's shell is listed in /etc/shells. It also checks that /etc/shells is a plain file and not world-writable.The module provides both auth and account module types. It returns PAMAUTHERR if the shell is not listed, PAMSUCCESS if the shell is valid, and PAMSERVICE_ERR if the username cannot be determined.

This module does not accept any parameters.

Requires /etc/shells to exist and contain valid shell paths (one absolute path per line). Users with shells not listed in /etc/shells will be denied access. Blank lines and lines starting with # in /etc/shells are ignored.

pam_shells is part of the Linux-PAM (Pluggable Authentication Modules) framework, providing a simple mechanism to restrict access based on whether a user has a legitimate login shell.

pam(8), pam_unix(8), pam_deny(8), chsh(1), getent(1), login(1)