<!-- Auth_radius Module User's Guide -->

<chapter>
    <chapterinfo>
	<revhistory>
	    <revision>
		<revnumber>$Revision: 1.1.8.1 $</revnumber>
		<date>$Date: 2004/07/18 22:56:23 $</date>
	    </revision>
	</revhistory>
    </chapterinfo>
    <title>User's Guide</title>
    
    <section>
	<title>Overview</title>
	<para>
	    This module contains functions that are used to perform authentication using a Radius
	    server. Basically the proxy will pass along the credentials to the radius server which
	    will in turn send a reply containing result of the authentication. So basically the
	    whole authentication is done in the Radius server. Before sending the request to the
	    radius server we perform some sanity checks over the credentials to make sure that only
	    well formed credentials will get to the server. We have implemented radius
	    authentication according to draft-sterman-aaa-sip-00. This module requires radiusclient
	    library version 0.4.1 or higher which is available from <ulink url='http://developer.berlios.de/projects/radiusclient-ng/'>
	    http://developer.berlios.de/projects/radiusclient-ng/</ulink>.
	</para>
	<para>How to configure radius server -- more detailed description -- TBD.</para>
	<warning>
	    <para>The detailed description of radius authentication setup is important since many
	    people will use it and we want to make the setup painless.</para>
	</warning>
    </section>
    <section>
	<title>Dependencies</title>
	<para>
	    The module depends on the following modules (in the other words the listed modules
	    must be loaded before this module):
	    <itemizedlist>
		<listitem>
		    <para><emphasis>auth</emphasis> -- Generic authentication functions</para>
		</listitem>
	    </itemizedlist>
	</para>
    </section>
    <section>
	<title>Exported Parameters</title>
	<section>
	    <title><varname>radius_config</varname> (string)</title>
	    <para>
		This is the location of the configuration file of radius client libraries.
	    </para>
	    <para>
		Default value is <quote>/usr/local/etc/radiusclient/radiusclient.conf</quote>.
	    </para>
	    <example>
		<title><varname>radius_config</varname> parameter usage</title>
		<programlisting format="linespecific">
modparam("auth_radius", "radius_config", "/etc/radiusclient.conf")
</programlisting>
	    </example>
	</section>
	<section>
	    <title><varname>service_type</varname> (integer)</title>
	    <para>
		This is the value of the Service-Type radius attribute to be used. The default
		should be fine for most people. See your radius client include files for numbers to
		be put in this parameter if you need to change it.
	    </para>
	    <para>
		Default value is <quote>15</quote>.
	    </para>
	    <example>
		<title><varname>radius_config</varname> usage</title>
		<programlisting format="linespecific">
modparam("auth_radius", "service_type", 15)
</programlisting>
	    </example>
	</section>
    </section>

    <section>
	<title>Exported Functions</title>
	<section>
	    <title><function moreinfo="none">radius_www_authorize(realm)</function></title>
	    <para>
		The function verifies credencials according to RFC2617. If the credentials are
		verified sucessfully then the function will succeed and mark the credentials as
		authorized (marked credentials can be later used by some other functions). If the
		function was unable to verify the credentials for some reason then it will fail and
		the script should call <function moreinfo="none">www_challenge</function> which will
		challenge the user again.
	    </para>
	    <para>
		This function will, in fact, perform sanity checks over the received credentials and
		then pass them along to the radius server which will verify the credentials and
		return whether they are valid or not.
	    </para>
	    <para>Meaning of the parameter is as follows:</para>
	    <itemizedlist>
		<listitem>
		    <para><emphasis>realm</emphasis> - Realm is a opaque string that the user agent
		    should present to the user so he can decide what username and password to
		    use. Usualy this is domain of the host the server is running on.
		    </para>
		    <para>
			If an empty string <quote></quote> is used then the server will generate it
			from the request. In case of REGISTER requests To header field domain will
			be used (because this header field represents a user being registered), for
			all other messages From header field domain will be used.
		    </para>
		</listitem>
	    </itemizedlist>
	    <example>
		<title><function moreinfo="none">radius_www_authorize</function> usage</title>
		<programlisting format="linespecific">
...
if (radius_www_authorize("iptel.org")) {
    www_challenge("iptel.org", "1");
};
...
</programlisting>
	    </example>
	</section>

	<section>
	    <title><function moreinfo="none">radius_proxy_authorize(realm)</function></title>
	    <para>
		The function verifies credencials according to RFC2617. If the credentials are
		verified sucessfully then the function will succeed and mark the credentials as
		authorized (marked credentials can be later used by some other functions). If the
		function was unable to verify the credentials for some reason then it will fail and
		the script should call <function moreinfo="none">proxy_challenge</function> which will
		challenge the user again.
	    </para>
	    <para>
		This function will, in fact, perform sanity checks over the received credentials and
		then pass them along to the radius server which will verify the credentials and
		return whether they are valid or not.
	    </para>
	    <para>Meaning of the parameter is as follows:</para>
	    <itemizedlist>
		<listitem>
		    <para><emphasis>realm</emphasis> - Realm is a opaque string that the user agent
		    should present to the user so he can decide what username and password to
		    use. Usualy this is domain of the host the server is running on.
		    </para>
		    <para>
			If an empty string <quote></quote> is used then the server will generate it
			from the request. From header field domain will be used as realm.
		    </para>
		</listitem>
	    </itemizedlist>
	    <example>
		<title>proxy_authorize usage</title>
		<programlisting format="linespecific">
...
if (!radius_proxy_authorize("")) {
    proxy_challenge("", "1");  # Realm will be autogenerated
};
...
</programlisting>
	    </example>
	</section>
    </section>
</chapter>

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