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<?xml version="1.0" encoding='UTF-8'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd">
<refentry id="pam_securetty">
<refmeta>
<refentrytitle>pam_securetty</refentrytitle>
<manvolnum>8</manvolnum>
<refmiscinfo class="sectdesc">Linux-PAM Manual</refmiscinfo>
</refmeta>
<refnamediv id="pam_securetty-name">
<refname>pam_securetty</refname>
<refpurpose>Limit root login to special devices</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis id="pam_securetty-cmdsynopsis">
<command>pam_securetty.so</command>
<arg choice="opt">
debug
</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 id="pam_securetty-description">
<title>DESCRIPTION</title>
<para>
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 <filename>securetty</filename> file. pam_securetty checks at
first, if <filename>/etc/securetty</filename> exists. If not and
it was built with vendordir support, it will use
<filename>%vendordir%/securetty</filename>. pam_securetty also
checks that the <filename>securetty</filename> files are plain
files and not world writable. It will also allow root logins on
the tty specified with <option>console=</option> switch on the
kernel command line and on ttys from the
<filename>/sys/class/tty/console/active</filename>.
</para>
<para>
This module has no effect on non-root users and requires that the
application fills in the <emphasis remap='B'>PAM_TTY</emphasis>
item correctly.
</para>
<para>
For canonical usage, should be listed as a
<emphasis remap='B'>required</emphasis> authentication method
before any <emphasis remap='B'>sufficient</emphasis>
authentication methods.
</para>
</refsect1>
<refsect1 id="pam_securetty-options">
<title>OPTIONS</title>
<variablelist>
<varlistentry>
<term>
<option>debug</option>
</term>
<listitem>
<para>
Print debug information.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>noconsole</option>
</term>
<listitem>
<para>
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
<filename>securetty</filename> file.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id="pam_securetty-types">
<title>MODULE TYPES PROVIDED</title>
<para>
Only the <option>auth</option> module type is provided.
</para>
</refsect1>
<refsect1 id='pam_securetty-return_values'>
<title>RETURN VALUES</title>
<variablelist>
<varlistentry>
<term>PAM_SUCCESS</term>
<listitem>
<para>
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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_AUTH_ERR</term>
<listitem>
<para>
Authentication is rejected. Either root is attempting to
log in via an unacceptable device, or the
<filename>securetty</filename> file is world writable or
not a normal file.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_BUF_ERR</term>
<listitem>
<para>
Memory buffer error.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_CONV_ERR</term>
<listitem>
<para>
The conversation method supplied by the application
failed to obtain the username.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_INCOMPLETE</term>
<listitem>
<para>
The conversation method supplied by the application
returned PAM_CONV_AGAIN.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_SERVICE_ERR</term>
<listitem>
<para>
An error occurred while the module was determining the
user's name or tty, or the module could not open
the <filename>securetty</filename> file.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_USER_UNKNOWN</term>
<listitem>
<para>
The module could not find the user name in the
<filename>/etc/passwd</filename> file to verify whether
the user had a UID of 0. Therefore, the results of running
this module are ignored.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='pam_securetty-examples'>
<title>EXAMPLES</title>
<para>
<programlisting>
auth required pam_securetty.so
auth required pam_unix.so
</programlisting>
</para>
</refsect1>
<refsect1 id='pam_securetty-see_also'>
<title>SEE ALSO</title>
<para>
<citerefentry>
<refentrytitle>securetty</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>pam.conf</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>pam.d</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>
</para>
</refsect1>
<refsect1 id='pam_securetty-author'>
<title>AUTHOR</title>
<para>
pam_securetty was written by Elliot Lee <sopwith@cuc.edu>.
</para>
</refsect1>
</refentry>
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