
AUTH_DIAMETER Module

Elena-Ramona Modroiu

   FhG FOKUS

Edited by

Elena-Ramona Modroiu

   Copyright © 2003, 2004 FhG FOKUS
     _________________________________________________________

   Table of Contents
   1. User's Guide

        1.1. Overview
        1.2. Dependencies

              1.2.1. SER Modules
              1.2.2. External Libraries or Applications

        1.3. Exported Parameters

              1.3.1. diameter_client_host (string)
              1.3.2. diameter_client_port (string)
              1.3.3. use_domain (int)

        1.4. Exported Functions

              1.4.1. diameter_www_authorize(realm)
              1.4.2. diameter_proxy_authorize(realm)
              1.4.3. diameter_is_user_in(who, group)

        1.5. Installation & Running

   2. Developer's Guide
   3. Frequently Asked Questions

   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. User's Guide

1.1. Overview

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

   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

...
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1.2. Dependencies

1.2.1. SER Modules

   The following modules must be loaded before this module:

     * sl - used to send stateless replies.
     _________________________________________________________

1.2.2. External Libraries or Applications

   The following libraries or applications must be installed
   before running SER with this module loaded:

     * None.
     _________________________________________________________

1.3. Exported Parameters

1.3.1. 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")
...
     _________________________________________________________

1.3.2. diameter_client_port (string)

   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")
...
     _________________________________________________________

1.3.3. 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)
...
     _________________________________________________________

1.4. Exported Functions

1.4.1. 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.

   Meaning of the parameters is as follows:

     * realm - the realm to be use for authentication and
       authorization.

   Example 1-5. diameter_www_authorize usage
...
if(!diameter_www_authorize("iptel.org"))
{ /* user is not authorized */
        break;
};
...
     _________________________________________________________

1.4.2. 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.

   Meaning of the parameters is as follows:

     * realm - the realm to be use for authentication and
       authorization.

   Example 1-6. diameter_proxy_authorize usage
...
if(!diameter_proxy_authorize("iptel.org"))
{ /* user is not authorized */
        break;
};
...
     _________________________________________________________

1.4.3. 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.

   Example 1-7. diameter_is_user_in usage
...
if(!diameter_is_user_in("From", "voicemail"))
{ /* user is not authorized */
        break;
};
...
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1.5. Installation & Running

   Notes about installation and running.
     _________________________________________________________

Chapter 2. Developer's Guide

   The module does not provide any sort of API to use in other
   SER modules.
     _________________________________________________________

Chapter 3. Frequently Asked Questions

   3.1. Where can I find more about SER?
   3.2. Where can I post a question about this module?
   3.3. How can I report a bug?

   3.1. Where can I find more about SER?

   Take a look at http://iptel.org/ser.

   3.2. Where can I post a question about this module?

   First at all check if your question was already answered on
   one of our mailing lists:

     * http://mail.iptel.org/mailman/listinfo/serusers
     * http://mail.iptel.org/mailman/listinfo/serdev

   E-mails regarding any stable version should be sent to
   <serusers@iptel.org> and e-mail regarding development versions
   or CVS snapshots should be send to <serdev@iptel.org>.

   If you want to keep the mail private, send it to
   <serhelp@iptel.org>.

   3.3. How can I report a bug?

   Please follow the guidelines provided at:
   http://iptel.org/ser/bugs
