<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>4.3. Example configuration file entries</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="Linux-PAM_SAG.html" title="The Linux-PAM System Administrators' Guide"><link rel="up" href="sag-configuration.html" title="Chapter 4. The Linux-PAM configuration file"><link rel="prev" href="sag-configuration-directory.html" title="4.2. Directory based configuration"><link rel="next" href="sag-security-issues.html" title="Chapter 5. Security issues"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">4.3. Example configuration file entries</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="sag-configuration-directory.html">Prev</a> </td><th width="60%" align="center">Chapter 4. The Linux-PAM configuration file</th><td width="20%" align="right"> <a accesskey="n" href="sag-security-issues.html">Next</a></td></tr></table><hr></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sag-configuration-example"></a>4.3. Example configuration file entries</h2></div></div></div><p>
In this section, we give some examples of entries that can
be present in the <span class="emphasis"><em>Linux-PAM</em></span>
configuration file. As a first attempt at configuring your
system you could do worse than to implement these.
</p><p>
If a system is to be considered secure, it had better have a
reasonably secure '<span class="emphasis"><em>other</em></span> entry.
The following is a paranoid setting (which is not a bad place
to start!):
</p><pre class="programlisting">
#
# default; deny access
#
other auth required pam_deny.so
other account required pam_deny.so
other password required pam_deny.so
other session required pam_deny.so
</pre><p>
Whilst fundamentally a secure default, this is not very
sympathetic to a misconfigured system. For example, such
a system is vulnerable to locking everyone out should the
rest of the file become badly written.
</p><p>
The module <span class="command"><strong>pam_deny</strong></span> (documented in a
<a class="link" href="sag-pam_deny.html" title="6.4. pam_deny - locking-out PAM module">later section</a>) is not very
sophisticated. For example, it logs no information when it
is invoked so unless the users of a system contact the
administrator when failing to execute a service application,
the administrator may go for a long while in ignorance of the
fact that his system is misconfigured.
</p><p>
The addition of the following line before those in the above
example would provide a suitable warning to the administrator.
</p><pre class="programlisting">
#
# default; wake up! This application is not configured
#
other auth required pam_warn.so
other password required pam_warn.so
</pre><p>
Having two '<span class="command"><strong>other auth</strong></span>' lines is an
example of stacking.
</p><p>
On a system that uses the <code class="filename">/etc/pam.d/</code>
configuration, the corresponding default setup would be
achieved with the following file:
</p><pre class="programlisting">
#
# default configuration: /etc/pam.d/other
#
auth required pam_warn.so
auth required pam_deny.so
account required pam_deny.so
password required pam_warn.so
password required pam_deny.so
session required pam_deny.so
</pre><p>
This is the only explicit example we give for an
<code class="filename">/etc/pam.d/</code> file. In general, it
should be clear how to transpose the remaining examples
to this configuration scheme.
</p><p>
On a less sensitive computer, one on which the system
administrator wishes to remain ignorant of much of the
power of <span class="emphasis"><em>Linux-PAM</em></span>, the
following selection of lines (in
<code class="filename">/etc/pam.d/other</code>) is likely to
mimic the historically familiar Linux setup.
</p><pre class="programlisting">
#
# default; standard UN*X access
#
auth required pam_unix.so
account required pam_unix.so
password required pam_unix.so
session required pam_unix.so
</pre><p>
In general this will provide a starting place for most applications.
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