pam_securetty(8) — Linux manual page

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 /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(8)

AUTHOR

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

COLOPHON

       This page is part of the linux-pam (Pluggable Authentication
       Modules for Linux) project.  Information about the project can be
       found at ⟨http://www.linux-pam.org/⟩.  If you have a bug report
       for this manual page, see ⟨//www.linux-pam.org/⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨https://github.com/linux-pam/linux-pam.git⟩ on 2023-12-22.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2023-12-18.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

Linux-PAM Manual               12/22/2023               PAM_SECURETTY(8)

Pages that refer to this page: securetty(5)

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