AUTH_DIAMETER Module

Elena-Ramona Modroiu

   rosdev.ro

Edited by

Elena-Ramona Modroiu

   Copyright © 2003, 2004 FhG FOKUS
     __________________________________________________________________

   Table of Contents

   1. Admin Guide

        1. Overview
        2. Dependencies

              2.1. Kamailio Modules
              2.2. External Libraries or Applications

        3. Parameters

              3.1. diameter_client_host (string)
              3.2. diameter_client_port (int)
              3.3. use_domain (int)

        4. Functions

              4.1. diameter_www_authorize(realm)
              4.2. diameter_proxy_authorize(realm)
              4.3. diameter_is_user_in(who, group)

        5. Installation and Running

   List of Examples

   1.1. Digest Authentication
   1.2. Set diameter_client_host parameter
   1.3. Set diameter_client_port parameter
   1.4. Set use_domain parameter
   1.5. diameter_www_authorize usage
   1.6. diameter_proxy_authorize usage
   1.7. diameter_is_user_in usage

Chapter 1. Admin Guide

   Table of Contents

   1. Overview
   2. Dependencies

        2.1. Kamailio Modules
        2.2. External Libraries or Applications

   3. Parameters

        3.1. diameter_client_host (string)
        3.2. diameter_client_port (int)
        3.3. use_domain (int)

   4. Functions

        4.1. diameter_www_authorize(realm)
        4.2. diameter_proxy_authorize(realm)
        4.3. diameter_is_user_in(who, group)

   5. Installation and Running

1. Overview

   This module implements SIP authentication and authorization with
   DIAMETER server, namely DIameter Server Client (DISC).

   NOTE: diameter support was developed for DISC (DIameter Server Client
   project at http://developer.berlios.de/projects/disc/). This project
   seems to be no longer maintained and DIAMETER specifications were
   updated in the meantime. Thus, the module is obsolete and needs rework
   to be usable with opendiameter or other DIAMETER servers.

   The digest authentication mechanism is presented in next figure.

   Example 1.1. Digest Authentication
...
        a) First phase of Digest Authentication for SIP:


     +----+ SIP INVITE   +=====+  DIAMETER      +------+       +------+
     |    | no Auth hdr  #/////#  AA-Request    |      |       |      |
     |    |---------1--->#/////#-------2------->|      |---2-->|      |
     |UAC |              #UAS//#                |DClnt |       |DSrv  |
     |    |<-----4-------#(SER)#<------3--------|(DISC)|<--3---|(DISC)|
     |    |     401      #/////#  DIAMETER      |      |       |      |
     +----+ Unauthorized +=====+  AA-Answer     +------+       +------+
                                  Result-Code=4001


        b) Second phase of Digest Authentication for SIP:


     +----+ SIP INVITE   +=====+  DIAMETER     +------+       +----+
     |    | Auth hdr     #/////#  AA-Request   |      |       |    |
     |    |--------1---->#/////#-------2------>|      |---2-->|    |
     |UAC |              #UAS//#               |DClnt |       |DSrv|
     |    |<-------4-----#(SER)#<------3-------|      |<--3---|    |
     |    |      200 OK  #/////#  DIAMETER     |      |       |    |
     +----+              +=====+  AA-Answer    +------+       +----+
                                  Result-Code=2001

...

2. Dependencies

   2.1. Kamailio Modules
   2.2. External Libraries or Applications

2.1. Kamailio Modules

   The following modules must be loaded before this module:
     * sl - used to send stateless replies.

2.2. External Libraries or Applications

   The following libraries or applications must be installed before
   running Kamailio with this module loaded:
     * None.

3. Parameters

   3.1. diameter_client_host (string)
   3.2. diameter_client_port (int)
   3.3. use_domain (int)

3.1. diameter_client_host (string)

   Hostname of the machine where the DIAMETER Client is running.

   Default value is “localhost”.

   Example 1.2. Set diameter_client_host parameter
...
modparam("auth_diameter", "diameter_client_host", "10.10.10.10")
...

3.2. diameter_client_port (int)

   Port number where the DIAMETER Client is listening.

   Default value is “3000”.

   Example 1.3. Set diameter_client_port parameter
...
modparam("auth_diameter", "diameter_client_port", 3000)
...

3.3. use_domain (int)

   Specifies whether the domain name part of URI is used when checking the
   user's privileges.

   Default value is “0 (0==false and 1==true )”.

   Example 1.4. Set use_domain parameter
...
modparam("auth_diameter", "use_domain", 1)
...

4. Functions

   4.1. diameter_www_authorize(realm)
   4.2. diameter_proxy_authorize(realm)
   4.3. diameter_is_user_in(who, group)

4.1.  diameter_www_authorize(realm)

   SIP Server checks for authorization having a DIAMETER server in
   backend. If no credentials are provided inside the SIP request then a
   challenge is sent back to UAC. If the credentials don't match the ones
   computed by DISC then “403 Forbidden” is sent back.

   Negative codes may be interpreted as follows:
     * -5 (generic error) - some generic error occurred and no reply was
       sent out;
     * -3 (stale nonce) - stale nonce;

   Meaning of the parameters is as follows:
     * realm - the realm to be use for authentication and authorization.
       The string may contain pseudo variables.

   This function can be used from REQUEST_ROUTE.

   Example 1.5. diameter_www_authorize usage
...
if(!diameter_www_authorize("siphub.net"))
{ /* user is not authorized */
        exit;
};
...

4.2.  diameter_proxy_authorize(realm)

   SIP Proxy checks for authorization having a DIAMETER server in backend.
   If no credentials are provided inside the SIP request then a challenge
   is sent back to UAC. If the credentials don't match the ones computed
   by DISC then “403 Forbidden” is sent back. For more about the negative
   return codes, see the above function.

   Meaning of the parameters is as follows:
     * realm - the realm to be use for authentication and authorization.
       The string may contain pseudo variables.

   This function can be used from REQUEST_ROUTE.

   Example 1.6. diameter_proxy_authorize usage
...
if(!diameter_proxy_authorize("siphub.net"))
{ /* user is not authorized */
        exit;
};
...

4.3.  diameter_is_user_in(who, group)

   The method performs group membership checking with DISC.

   Meaning of the parameters is as follows:
     * who - what header to be used to get the SIP URI that is wanted to
       be checked being member in a certain group. It can be:
       “Request-URI”, “From”, “To” or “Credentials”.
     * group - the group name where to check if the user is part of.

   This function can be used from REQUEST_ROUTE.

   Example 1.7. diameter_is_user_in usage
...
if(!diameter_is_user_in("From", "voicemail"))
{ /* user is not authorized */
        exit;
};
...

5. Installation and Running

   Notes about installation and running.