Auth_aaa Module
     __________________________________________________________

   Table of Contents

   1. Admin Guide

        1.1. Overview
        1.2. Additional Credentials
        1.3. Dependencies

              1.3.1. OpenSIPS Modules
              1.3.2. External Libraries or Applications

        1.4. Exported Parameters

              1.4.1. aaa_url (string)
              1.4.2. auth_service_type (integer)
              1.4.3. check_service_type (integer)
              1.4.4. use_ruri_flag (string)

        1.5. Exported Functions

              1.5.1. aaa_www_authorize(realm, [uri_user])
              1.5.2. aaa_proxy_authorize(realm, [uri_user])
              1.5.3. aaa_does_uri_exist([sip_uri])
              1.5.4. aaa_does_uri_user_exist([sip_uri])

   2. Contributors

        2.1. By Commit Statistics
        2.2. By Commit Activity

   3. Documentation

        3.1. Contributors

   List of Tables

   2.1. Top contributors by DevScore^(1), authored commits^(2) and
          lines added/removed^(3)

   2.2. Most recently active contributors^(1) to this module

   List of Examples

   1.1. “SIP-AVP” AAA AVP examples
   1.2. aaa_url parameter usage
   1.3. auth_service_type parameter usage
   1.4. Set check_service_type parameter
   1.5. use_ruri_flag parameter usage
   1.6. aaa_www_authorize usage
   1.7. proxy_authorize usage
   1.8. aaa_does_uri_exist usage
   1.9. aaa_does_uri_user_exist usage

Chapter 1. Admin Guide

1.1. Overview

   This module contains functions that are used to perform digest
   authentication and some URI checks against an AAA server. In
   order to perform the authentication, the proxy will pass along
   the credentials to the AAA server which will in turn send a
   reply containing result of the authentication. So basically the
   whole authentication is done in the AAA server. Before sending
   the request to the AAA server we perform some sanity checks
   over the credentials to make sure that only well formed
   credentials will get to the server.

1.2. Additional Credentials

   When performing authentication, the AAA server may include in
   the response additional credentials. This scheme is very useful
   in fetching additional user information from the AAA server
   without making extra queries.

   The additional credentials are embedded in the AAA reply as
   AVPs “SIP-AVP”. The syntax of the value is:
     * value = SIP_AVP_NAME SIP_AVP_VALUE
     * SIP_AVP_NAME = STRING_NAME | '#'ID_NUMBER
     * SIP_AVP_VALUE = ':'STRING_VALUE | '#'NUMBER_VALUE

   All additional credentials will be stored as OpenSIPS AVPs
   (SIP_AVP_NAME = SIP_AVP_VALUE).

   The RPID value may be fetch via this mechanism.

   Example 1.1. “SIP-AVP” AAA AVP examples
....
"email:joe@yahoo.com"
    - STRING NAME AVP (email) with STRING VALUE (joe@yahoo.com)
"#14:joe@yahoo.com"
    - ID AVP (14) with STRING VALUE (joe@yahoo.com)
"age#28"
    - STRING NAME AVP (age) with INTEGER VALUE (28)
"#14#28"
    - ID AVP (14) with INTEGER VALUE (28)
....

1.3. Dependencies

1.3.1. OpenSIPS Modules

   The module depends on the following modules (in the other words
   the listed modules must be loaded before this module):
     * auth -- Authentication framework, only if the auth
       functions are used from script
     * an aaa implementing module -- for example aaa_radius

1.3.2. External Libraries or Applications

   This module does not depend on any external library.

1.4. Exported Parameters

1.4.1. aaa_url (string)

   This is the url representing the AAA protocol used and the
   location of the configuration file of this protocol.

   The syntax for the url is the following:
   "name_of_the_aaa_protocol_used:path_of_the_configuration_file"

   Example 1.2. aaa_url parameter usage

modparam("auth_aaa", "aaa_url", "radius:/etc/radiusclient-ng/radiusclien
t.conf")

1.4.2. auth_service_type (integer)

   This is the value of the Service-Type aaa attribute to be used
   when performing an authentication operation. The default should
   be fine for most people. See your aaa client include files for
   numbers to be put in this parameter if you need to change it.

   Default value is “15”.

   Example 1.3. auth_service_type parameter usage

modparam("auth_aaa", "auth_service_type", 15)

1.4.3. check_service_type (integer)

   AAA service type used by aaa_does_uri_exist and
   aaa_does_uri_user_exist checks.

   Default value is 10 (Call-Check).

   Example 1.4. Set check_service_type parameter
...
modparam("auth_aaa", "check_service_type", 11)
...

1.4.4. use_ruri_flag (string)

   When this parameter is set to the value other than "NULL" and
   the request being authenticated has flag with matching number
   set via setflag() function, use Request URI instead of uri
   parameter value from the Authorization / Proxy-Authorization
   header field to perform AAA authentication. This is intended to
   provide workaround for misbehaving NAT / routers / ALGs that
   alter request in the transit, breaking authentication. At the
   time of this writing, certain versions of Linksys WRT54GL are
   known to do that.

   Default value is “NULL” (not set).

   Example 1.5. use_ruri_flag parameter usage

modparam("auth_aaa", "use_ruri_flag", "USE_RURI_FLAG")

1.5. Exported Functions

1.5.1. aaa_www_authorize(realm, [uri_user])

   The function verifies credentials according to RFC2617. If the
   credentials are verified successfully 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 www_challenge
   which will challenge the user again.

   Negative codes may be interpreted as follows:
     * -5 (generic error) - some generic error occurred and no
       reply was sent out;
     * -4 (no credentials) - credentials were not found in
       request;
     * -3 (stale nonce) - stale nonce;

   This function will, in fact, perform sanity checks over the
   received credentials and then pass them along to the aaa server
   which will verify the credentials and return whether they are
   valid or not.

   Meaning of the parameter is as follows:
     * realm (string) - Realm is a opaque string that the user
       agent should present to the user so he can decide what
       username and password to use. Usually this is domain of the
       host the server is running on.
       If an empty string “” 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.
       The string may contain pseudo variables.
     * uri_user (string, optional) - value passed to the Radius
       server as value of the SIP-URI-User check item. If this
       parameter is not present, the server will generate the
       SIP-URI-User check item value from the username part of the
       To header field URI.

   This function can be used from REQUEST_ROUTE.

   Example 1.6. aaa_www_authorize usage

...
if (!aaa_www_authorize("siphub.net")) {
        www_challenge("siphub.net", "1");
};
...


1.5.2. aaa_proxy_authorize(realm, [uri_user])

   The function verifies credentials according to RFC2617. If the
   credentials are verified successfully 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 proxy_challenge
   which will challenge the user again. For more about the
   negative return codes, see the above function.

   This function will, in fact, perform sanity checks over the
   received credentials and then pass them along to the aaa server
   which will verify the credentials and return whether they are
   valid or not.

   Meaning of the parameters is as follows:
     * realm (string) - Realm is a opaque string that the user
       agent should present to the user so he can decide what
       username and password to use. This is usually one of the
       domains the proxy is responsible for. If an empty string “”
       is used then the server will generate realm from host part
       of From header field URI.
       The string may contain pseudo variables.
     * uri_user (string, optional) - value passed to the Radius
       server as value of the SIP-URI-User check item. If this
       parameter is not present, the server will generate the
       SIP-URI-User check item value from the username part of the
       To header field URI.

   This function can be used from REQUEST_ROUTE.

   Example 1.7. proxy_authorize usage

...
if (!aaa_proxy_authorize("")) {   # Realm and URI user will be autogener
ated
        proxy_challenge("", "1");
};
...
if (!aaa_proxy_authorize($pd, $pU)) { # Realm and URI user are taken
        proxy_challenge($pd, "1");         # from P-Preferred-Identity
};                                           # header field
...


1.5.3.  aaa_does_uri_exist([sip_uri])

   Checks from Radius if the SIP URI stored in the "sip_uri"
   parameter (or user@host part of the Request-URI if "sip_uri" is
   not given) belongs to a local user. Can be used to decide if
   404 or 480 should be returned after lookup has failed. If yes,
   loads AVP based on SIP-AVP reply items returned from Radius.
   Each SIP-AVP reply item must have a string value of form:

     * value = SIP_AVP_NAME SIP_AVP_VALUE
     * SIP_AVP_NAME = STRING_NAME | '#'ID_NUMBER
     * SIP_AVP_VALUE = ':'STRING_VALUE | '#'NUMBER_VALUE

   Returns 1 if Radius returns Access-Accept, -1 if Radius returns
   Access-Reject, and -2 in case of internal error.

   This function can be used from REQUEST_ROUTE.

   Example 1.8. aaa_does_uri_exist usage
...
if (aaa_does_uri_exist()) {
        ...
};
...

1.5.4.  aaa_does_uri_user_exist([sip_uri])

   Similar to aaa_does_uri_exist, but check is done based only on
   Request-URI user part or user stored in "sip_uri". The user
   should thus be unique among all users, such as an E.164 number.

   This function can be used from REQUEST_ROUTE.

   Example 1.9. aaa_does_uri_user_exist usage
...
if (aaa_does_uri_user_exist()) {
        ...
};
...

Chapter 2. Contributors

2.1. By Commit Statistics

   Table 2.1. Top contributors by DevScore^(1), authored
   commits^(2) and lines added/removed^(3)
     Name DevScore Commits Lines ++ Lines --
   1. Jan Janak (@janakj) 87 24 3294 2182
   2. Bogdan-Andrei Iancu (@bogdan-iancu) 44 31 892 255
   3. Liviu Chircu (@liviuchircu) 17 14 73 119
   4. Daniel-Constantin Mierla (@miconda) 15 13 67 55
   5. Irina-Maria Stanescu 15 8 185 299
   6. Maksym Sobolyev (@sobomax) 11 6 167 171
   7. Razvan Crainea (@razvancrainea) 9 7 12 14
   8. Juha Heinanen (@juha-h) 8 5 142 53
   9. Andrei Pelinescu-Onciul 7 5 8 2
   10. Vlad Patrascu (@rvlad-patrascu) 7 2 55 213

   All remaining contributors: Jiri Kuthan (@jiriatipteldotorg),
   Henning Westerholt (@henningw), Ancuta Onofrei, Anatoly
   Pidruchny, Peter Nixon, Konstantin Bokarius, Peter Lemenkov
   (@lemenkov), Edson Gellert Schubert.

   (1) DevScore = author_commits + author_lines_added /
   (project_lines_added / project_commits) + author_lines_deleted
   / (project_lines_deleted / project_commits)

   (2) including any documentation-related commits, excluding
   merge commits. Regarding imported patches/code, we do our best
   to count the work on behalf of the proper owner, as per the
   "fix_authors" and "mod_renames" arrays in
   opensips/doc/build-contrib.sh. If you identify any
   patches/commits which do not get properly attributed to you,
   please submit a pull request which extends "fix_authors" and/or
   "mod_renames".

   (3) ignoring whitespace edits, renamed files and auto-generated
   files

2.2. By Commit Activity

   Table 2.2. Most recently active contributors^(1) to this module
                      Name                   Commit Activity
   1.  Bogdan-Andrei Iancu (@bogdan-iancu) Jun 2005 - May 2020
   2.  Liviu Chircu (@liviuchircu)         Jan 2013 - Jan 2020
   3.  Razvan Crainea (@razvancrainea)     Feb 2012 - Sep 2019
   4.  Vlad Patrascu (@rvlad-patrascu)     May 2017 - Apr 2019
   5.  Peter Lemenkov (@lemenkov)          Jun 2018 - Jun 2018
   6.  Irina-Maria Stanescu                Aug 2009 - Apr 2010
   7.  Daniel-Constantin Mierla (@miconda) Oct 2005 - Mar 2008
   8.  Konstantin Bokarius                 Mar 2008 - Mar 2008
   9.  Edson Gellert Schubert              Feb 2008 - Feb 2008
   10. Maksym Sobolyev (@sobomax)          Dec 2003 - Feb 2008

   All remaining contributors: Juha Heinanen (@juha-h), Henning
   Westerholt (@henningw), Ancuta Onofrei, Anatoly Pidruchny,
   Peter Nixon, Jan Janak (@janakj), Andrei Pelinescu-Onciul, Jiri
   Kuthan (@jiriatipteldotorg).

   (1) including any documentation-related commits, excluding
   merge commits

Chapter 3. Documentation

3.1. Contributors

   Last edited by: Liviu Chircu (@liviuchircu), Bogdan-Andrei
   Iancu (@bogdan-iancu), Peter Lemenkov (@lemenkov), Razvan
   Crainea (@razvancrainea), Irina-Maria Stanescu,
   Daniel-Constantin Mierla (@miconda), Konstantin Bokarius, Edson
   Gellert Schubert, Maksym Sobolyev (@sobomax), Henning
   Westerholt (@henningw), Anatoly Pidruchny, Juha Heinanen
   (@juha-h), Jan Janak (@janakj).

   Documentation Copyrights:

   Copyright © 2005-2009 Voice Sistem SRL

   Copyright © 2002-2003 FhG FOKUS
