<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="pam_keyinit">
<refmeta>
<refentrytitle>pam_keyinit</refentrytitle>
<manvolnum>8</manvolnum>
<refmiscinfo class="source">Linux-PAM</refmiscinfo>
<refmiscinfo class="manual">Linux-PAM Manual</refmiscinfo>
</refmeta>
<refnamediv xml:id="pam_keyinit-name">
<refname>pam_keyinit</refname>
<refpurpose>Kernel session keyring initialiser module</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis xml:id="pam_keyinit-cmdsynopsis" sepchar=" ">
<command>pam_keyinit.so</command>
<arg choice="opt" rep="norepeat">
debug
</arg>
<arg choice="opt" rep="norepeat">
force
</arg>
<arg choice="opt" rep="norepeat">
revoke
</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 xml:id="pam_keyinit-description">
<title>DESCRIPTION</title>
<para>
The pam_keyinit PAM module ensures that the invoking process has a
session keyring other than the user default session keyring.
</para>
<para>
The module checks to see if the process's session keyring is the
<citerefentry>
<refentrytitle>user-session-keyring</refentrytitle><manvolnum>7</manvolnum>
</citerefentry>,
and, if it is, creates a new
<citerefentry>
<refentrytitle>session-keyring</refentrytitle><manvolnum>7</manvolnum>
</citerefentry>
with which to replace it. If a new session keyring is created, it will
install a link to the
<citerefentry>
<refentrytitle>user-keyring</refentrytitle><manvolnum>7</manvolnum>
</citerefentry>
in the session keyring so that keys common to the user will be
automatically accessible through it. The session keyring of the invoking
process will thenceforth be inherited by all its children unless they override it.
</para>
<para>
In order to allow other PAM modules to attach tokens to the keyring, this module
provides both an <emphasis>auth</emphasis> (limited to
<citerefentry>
<refentrytitle>pam_setcred</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>
and a <emphasis>session</emphasis> component. The session keyring is created
in the module called. Moreover this module should be included as early as
possible in a PAM configuration.
</para>
<para>
This module is intended primarily for use by login processes. Be aware
that after the session keyring has been replaced, the old session keyring
and the keys it contains will no longer be accessible.
</para>
<para>
This module should not, generally, be invoked by programs like
<emphasis remap="B">su</emphasis>, since it is usually desirable for the
key set to percolate through to the alternate context. The keys have
their own permissions system to manage this.
</para>
<para>
The keyutils package is used to manipulate keys more directly. This
can be obtained from:
</para>
<para>
<link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://people.redhat.com/~dhowells/keyutils/">
Keyutils
</link>
</para>
</refsect1>
<refsect1 xml:id="pam_keyinit-options">
<title>OPTIONS</title>
<variablelist>
<varlistentry>
<term>
debug
</term>
<listitem>
<para>
Log debug information with <citerefentry>
<refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
force
</term>
<listitem>
<para>
Causes the session keyring of the invoking process to be replaced
unconditionally.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
revoke
</term>
<listitem>
<para>
Causes the session keyring of the invoking process to be revoked
when the invoking process exits if the session keyring was created
for this process in the first place.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 xml:id="pam_keyinit-types">
<title>MODULE TYPES PROVIDED</title>
<para>
Only the <option>session</option> module type is provided.
</para>
</refsect1>
<refsect1 xml:id="pam_keyinit-return_values">
<title>RETURN VALUES</title>
<variablelist>
<varlistentry>
<term>PAM_SUCCESS</term>
<listitem>
<para>
This module will usually return this value
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_AUTH_ERR</term>
<listitem>
<para>
Authentication failure.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_BUF_ERR</term>
<listitem>
<para>
Memory buffer error.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_IGNORE</term>
<listitem>
<para>
The return value should be ignored by PAM dispatch.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_SERVICE_ERR</term>
<listitem>
<para>
Cannot determine the user name.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_SESSION_ERR</term>
<listitem>
<para>
This module will return this value if its arguments are invalid or
if a system error such as ENOMEM occurs.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>PAM_USER_UNKNOWN</term>
<listitem>
<para>
User not known.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 xml:id="pam_keyinit-examples">
<title>EXAMPLES</title>
<para>
Add this line to your login entries to start each login session with its
own session keyring:
<programlisting>
session required pam_keyinit.so
</programlisting>
</para>
<para>
This will prevent keys from one session leaking into another session for
the same user.
</para>
</refsect1>
<refsect1 xml:id="pam_keyinit-see_also">
<title>SEE ALSO</title>
<para>
<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>,
<citerefentry>
<refentrytitle>keyctl</refentrytitle><manvolnum>1</manvolnum>
</citerefentry>
</para>
</refsect1>
<refsect1 xml:id="pam_keyinit-author">
<title>AUTHOR</title>
<para>
pam_keyinit was written by David Howells, <dhowells@redhat.com>.
</para>
</refsect1>
</refentry>