suauth.5.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
   SPDX-FileCopyrightText: 1996       , Marek Michałkiewicz
   SPDX-FileCopyrightText: 2001 - 2006, Tomasz Kłoczko
   SPDX-License-Identifier: BSD-3-Clause
-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
  "http:https://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!-- SHADOW-CONFIG-HERE -->
]>
<refentry id='suauth.5'>
  <!-- $Id$ -->
  <refentryinfo>
    <author>
      <firstname>Marek</firstname>
      <surname>Michałkiewicz</surname>
      <contrib>Creation, 1996</contrib>
    </author>
    <author>
      <firstname>Thomas</firstname>
      <surname>Kłoczko</surname>
      <email>kloczek@pld.org.pl</email>
      <contrib>shadow-utils maintainer, 2000 - 2007</contrib>
    </author>
    <author>
      <firstname>Nicolas</firstname>
      <surname>François</surname>
      <email>nicolas.francois@centraliens.net</email>
      <contrib>shadow-utils maintainer, 2007 - now</contrib>
    </author>
  </refentryinfo>
  <refmeta>
    <refentrytitle>suauth</refentrytitle>
    <manvolnum>5</manvolnum>
    <refmiscinfo class="sectdesc">File Formats and Configuration Files</refmiscinfo>
    <refmiscinfo class="source">shadow-utils</refmiscinfo>
    <refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
  </refmeta>
  <refnamediv id='name'>
    <refname>suauth</refname>
    <refpurpose>detailed su control file</refpurpose>
  </refnamediv>
  <!-- body begins here -->
  <refsynopsisdiv id='synopsis'>
    <cmdsynopsis>
      <command>/etc/suauth</command>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1 id='description'>
    <title>DESCRIPTION</title>
    <para>
      The file <filename>/etc/suauth</filename> is referenced whenever the
      su command is called. It can change the behaviour of the su command,
      based upon:
    </para>

    <!-- .RS -->
    <literallayout remap='.nf'>
      1) the user su is targeting
    </literallayout>
    <!-- .fi -->
    <para>
      2) the user executing the su command (or any groups he might be
      a member of)
    </para>

    <para>
      The file is formatted like this, with lines starting with a # being
      treated as comment lines and ignored;
    </para>

    <literallayout remap='RS'>
      to-id:from-id:ACTION
    </literallayout>

    <para>
      Where to-id is either the word <emphasis>ALL</emphasis>, a list of
      usernames delimited by "," or the words <emphasis>ALL
      EXCEPT</emphasis> followed by a list of usernames delimited by ",".
    </para>

    <para>
      from-id is formatted the same as to-id except the extra word
      <emphasis>GROUP</emphasis> is recognized. <emphasis>ALL EXCEPT
      GROUP</emphasis> is perfectly valid too. Following
      <emphasis>GROUP</emphasis> appears one or more group names, delimited
      by ",". It is not sufficient to have primary group id of the relevant
      group, an entry in
      <citerefentry><refentrytitle>/etc/group</refentrytitle>
      <manvolnum>5</manvolnum></citerefentry> is necessary.
    </para>

    <para> 
      Action can be one only of the following currently supported options.
    </para>
    <variablelist remap='TP'>
      <varlistentry>
	<term>
	  <emphasis>DENY</emphasis>
	</term>
	<listitem>
	  <para>The attempt to su is stopped before a password is
	    even asked for.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <emphasis>NOPASS</emphasis>
	</term>
	<listitem>
	  <para>
	    The attempt to su is automatically successful; no password is
	    asked for.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <emphasis>OWNPASS</emphasis>
	</term>
	<listitem>
	  <para>
	    For the su command to be successful, the user must enter his or
	    her own password. They are told this.
	  </para>
	</listitem>
      </varlistentry>
    </variablelist>

    <para>
      Note there are three separate fields delimited by a colon. No
      whitespace must surround this colon. Also note that the file is
      examined sequentially line by line, and the first applicable rule is
      used without examining the file further. This makes it possible for a
      system administrator to exercise as fine control as he or she wishes.
    </para>
  </refsect1>

  <refsect1 id='example'>
    <title>EXAMPLE</title>
    <literallayout remap='.nf'>
      # sample /etc/suauth file
      #
      # A couple of privileged usernames may
      # su to root with their own password.
      #
      root:chris,birddog:OWNPASS
      #
      # Anyone else may not su to root unless in
      # group wheel. This is how BSD does things.
      #
      root:ALL EXCEPT GROUP wheel:DENY
      #
      # Perhaps terry and birddog are accounts
      # owned by the same person.
      # Access can be arranged between them
      # with no password.
      #
      terry:birddog:NOPASS
      birddog:terry:NOPASS
      #
    </literallayout>
    <!-- .fi -->
  </refsect1>

  <refsect1 id='files'>
    <title>FILES</title>
    <variablelist>
      <varlistentry>
	<term><filename>/etc/suauth</filename></term>
	<listitem><para></para></listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1 id='bugs'>
    <title>BUGS</title>
    <para>
      There could be plenty lurking. The file parser is particularly
      unforgiving about syntax errors, expecting no spurious whitespace
      (apart from beginning and end of lines), and a specific token
      delimiting different things.
    </para>
  </refsect1>

  <refsect1 id='diagnostics'>
    <title>DIAGNOSTICS</title>
    <para>
      An error parsing the file is reported using
      <citerefentry><refentrytitle>syslogd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
      as level ERR on facility AUTH.
    </para>
  </refsect1>

  <refsect1 id='see_also'>
    <title>SEE ALSO</title>
    <para>
      <citerefentry>
	<refentrytitle>su</refentrytitle><manvolnum>1</manvolnum>
      </citerefentry>.
    </para>
  </refsect1>
</refentry>