csu3_am335x/EVSE/GPL/linux-pam-1.5.2/modules/pam_securetty/pam_securetty.8

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.\"     Title: pam_securetty
.\"    Author: [see the "AUTHOR" section]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 09/03/2021
.\"    Manual: Linux-PAM Manual
.\"    Source: Linux-PAM Manual
.\"  Language: English
.\"
.TH "PAM_SECURETTY" "8" "09/03/2021" "Linux-PAM Manual" "Linux\-PAM Manual"
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.SH "NAME"
pam_securetty \- Limit root login to special devices
.SH "SYNOPSIS"
.HP \w'\fBpam_securetty\&.so\fR\ 'u
\fBpam_securetty\&.so\fR [debug]
.SH "DESCRIPTION"
.PP
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
\fBconsole=\fR
switch on the kernel command line and on ttys from the
/sys/class/tty/console/active\&.
.PP
This module has no effect on non\-root users and requires that the application fills in the
\fBPAM_TTY\fR
item correctly\&.
.PP
For canonical usage, should be listed as a
\fBrequired\fR
authentication method before any
\fBsufficient\fR
authentication methods\&.
.SH "OPTIONS"
.PP
\fBdebug\fR
.RS 4
Print debug information\&.
.RE
.PP
\fBnoconsole\fR
.RS 4
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\&.
.RE
.SH "MODULE TYPES PROVIDED"
.PP
Only the
\fBauth\fR
module type is provided\&.
.SH "RETURN VALUES"
.PP
PAM_SUCCESS
.RS 4
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\&.
.RE
.PP
PAM_AUTH_ERR
.RS 4
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\&.
.RE
.PP
PAM_BUF_ERR
.RS 4
Memory buffer error\&.
.RE
.PP
PAM_CONV_ERR
.RS 4
The conversation method supplied by the application failed to obtain the username\&.
.RE
.PP
PAM_INCOMPLETE
.RS 4
The conversation method supplied by the application returned PAM_CONV_AGAIN\&.
.RE
.PP
PAM_SERVICE_ERR
.RS 4
An error occurred while the module was determining the user\*(Aqs name or tty, or the module could not open the
securetty
file\&.
.RE
.PP
PAM_USER_UNKNOWN
.RS 4
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\&.
.RE
.SH "EXAMPLES"
.PP
.if n \{\
.RS 4
.\}
.nf
auth  required  pam_securetty\&.so
auth  required  pam_unix\&.so
      
.fi
.if n \{\
.RE
.\}
.sp
.SH "SEE ALSO"
.PP
\fBsecuretty\fR(5),
\fBpam.conf\fR(5),
\fBpam.d\fR(5),
\fBpam\fR(8)
.SH "AUTHOR"
.PP
pam_securetty was written by Elliot Lee <sopwith@cuc\&.edu>\&.