pam_securetty

PAM_SECURETTY(8)               Linux-PAM Manual               PAM_SECURETTY(8)

NAME
       pam_securetty - Limit root login to special devices

SYNOPSIS
       pam_securetty.so [debug]

DESCRIPTION
       pam_securetty is a PAM module that allows root logins only if the user
       is logging in on a "secure" tty, as defined by the listing in the
       securetty file. pam_securetty checks at first, if /etc/securetty
       exists. If not and it was built with vendordir support, it will use
       <vendordir>/securetty. pam_securetty also checks that the securetty
       files are plain files and not world writable. It will also allow root
       logins on the tty specified with console= switch on the kernel command
       line and on ttys from the /sys/class/tty/console/active.

       This module has no effect on non-root users and requires that the
       application fills in the PAM_TTY item correctly.

       For canonical usage, should be listed as a required authentication
       method before any sufficient authentication methods.

OPTIONS
       debug
           Print debug information.

       noconsole
           Do not automatically allow root logins on the kernel console
           device, as specified on the kernel command line or by the sys file,
           if it is not also specified in the securetty file.

MODULE TYPES PROVIDED
       Only the auth module type is provided.

RETURN VALUES
       PAM_SUCCESS
           The user is allowed to continue authentication. Either the user is
           not root, or the root user is trying to log in on an acceptable
           device.

       PAM_AUTH_ERR
           Authentication is rejected. Either root is attempting to log in via
           an unacceptable device, or the securetty file is world writable or
           not a normal file.

       PAM_BUF_ERR
           Memory buffer error.

       PAM_CONV_ERR
           The conversation method supplied by the application failed to
           obtain the username.

       PAM_INCOMPLETE
           The conversation method supplied by the application returned
           PAM_CONV_AGAIN.

       PAM_SERVICE_ERR
           An error occurred while the module was determining the user's name
           or tty, or the module could not open the securetty file.

       PAM_USER_UNKNOWN
           The module could not find the user name in the /etc/passwd file to
           verify whether the user had a UID of 0. Therefore, the results of
           running this module are ignored.

EXAMPLES
           auth  required  pam_securetty.so
           auth  required  pam_unix.so

SEE ALSO
       securetty(5), pam.conf(5), pam.d(5), pam(7)

AUTHOR
       pam_securetty was written by Elliot Lee <sopwith@cuc.edu>.

Linux-PAM Manual                  06/08/2020                  PAM_SECURETTY(8)