AUTH_DIAMETER Module

Elena-Ramona Modroiu

   rosdev.ro

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. OpenSER 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 (int)
              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
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Chapter 1. User's Guide

1.1. 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   This project seems to be no longer maintained and DIAMETER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   is obsolete and needs rework to be usable with opendiameter or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

...
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1.2. Dependencies

1.2.1. OpenSER 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 OpenSER 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 (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)
...
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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)
...
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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.

   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;
};
...
     __________________________________________________________

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. 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;
};
...
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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.

   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;
};
...
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1.5. Installation & Running

   Notes about installation and running.
     __________________________________________________________

Chapter 2. Developer's Guide

   The module does not provide any API to use in other OpenSER
   modules.
     __________________________________________________________

Chapter 3. Frequently Asked Questions

   3.1. Where can I find more about OpenSER?
   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 OpenSER?

   Take a look at http://www.openser.org/.

   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:

     * User Mailing List -
       http://lists.openser.org/cgi-bin/mailman/listinfo/users
     * Developer Mailing List -
       http://lists.openser.org/cgi-bin/mailman/listinfo/devel

   E-mails regarding any stable OpenSER release should be sent to
   <users@lists.openser.org> and e-mails regarding development
   versions should be sent to <devel@lists.openser.org>.

   If you want to keep the mail private, send it to
   <team@lists.openser.org>.

   3.3. How can I report a bug?

   Please follow the guidelines provided at:
   http://sourceforge.net/tracker/?group_id=139143.