
Auth_db Module

Jan Janak

   FhG Fokus

Jakob Schlyter

Bogdan-Andrei Iancu

   voice-system.ro

Edited by

Jan Janak

   Copyright © 2002, 2003 FhG FOKUS

   Copyright © 2005 voice-system.ro
     _________________________________________________________

   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. db_url (string)
              1.3.2. user_column (string)
              1.3.3. domain_column (string)
              1.3.4. password_column (string)
              1.3.5. password_column_2 (string)
              1.3.6. calculate_ha1 (integer)
              1.3.7. use_domain (integer)
              1.3.8. load_credentials (string)

        1.4. Exported Functions

              1.4.1. www_authorize(realm, table)
              1.4.2. proxy_authorize(realm, table)

   2. Developer's Guide
   3. Frequently Asked Questions

   List of Examples
   1-1. db_url parameter usage
   1-2. user_column parameter usage
   1-3. domain_column parameter usage
   1-4. password_column parameter usage
   1-5. password_column_2 parameter usage
   1-6. calculate_ha1 parameter usage
   1-7. use_domain parameter usage
   1-8. load_credentials parameter usage
   1-9. www_authorize usage
   1-10. proxy_authorize usage
     _________________________________________________________

Chapter 1. User's Guide

1.1. Overview

   This module contains all authentication related functions that
   need the access to the database. This module should be used
   together with auth module, it cannot be used independently
   because it depends on the module. Select this module if you
   want to use database to store authentication information like
   subscriber usernames and passwords. If you want to use radius
   authentication, then use auth_radius instead.
     _________________________________________________________

1.2. Dependencies

1.2.1. OpenSER Modules

   The module depends on the following modules (in the other
   words the listed modules must be loaded before this module):

     * auth -- Generic authentication functions
     * database -- Any database module (currently mysql,
       postgres, dbtext)
     _________________________________________________________

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. db_url (string)

   This is URL of the database to be used. Value of the parameter
   depends on the database module used. For example for mysql and
   postgres modules this is something like
   mysql://username:password@host:port/database. For dbtext
   module (which stores data in plaintext files) it is directory
   in which the database resides.

   Default value is
   "mysql://openserro:openserro@localhost/openser".

   Example 1-1. db_url parameter usage
modparam("auth_db", "db_url", "mysql://foo:bar@foobar.org/openser")
     _________________________________________________________

1.3.2. user_column (string)

   This is the name of the column holding usernames. Default
   value is fine for most people. Use the parameter if you really
   need to change it.

   Default value is "username".

   Example 1-2. user_column parameter usage
modparam("auth_db", "user_column", "user")
     _________________________________________________________

1.3.3. domain_column (string)

   This is the name of the column holding domains of users.
   Default value is fine for most people. Use the parameter if
   you really need to change it.

   Default value is "domain".

   Example 1-3. domain_column parameter usage
modparam("auth_db", "domain_column", "domain")
     _________________________________________________________

1.3.4. password_column (string)

   This is the name of the column holding passwords. Passwords
   can be either stored as plain text or pre-calculated HA1
   strings. HA1 strings are MD5 hashes of username, password, and
   realm. HA1 strings are more safe because the server doesn't
   need to know plaintext passwords and they cannot be obtained
   from HA1 strings.

   Default value is "ha1".

   Example 1-4. password_column parameter usage
modparam("auth_db", "password_column", "password")
     _________________________________________________________

1.3.5. password_column_2 (string)

   As described in the previous section this parameter contains
   name of column holding pre-calculated HA1 string that were
   calculated including the domain in the username. This
   parameter is used only when calculate_ha1 is set to 0 and user
   agent send a credentials containing the domain in the
   username.

   Default value of the parameter is ha1b.

   Example 1-5. password_column_2 parameter usage
modparam("auth_db", "password_column_2", "ha1_2")
     _________________________________________________________

1.3.6. calculate_ha1 (integer)

   This parameter tells server whether it should expect plaintext
   passwords in the database or HA1 string. If the parameter is
   set to 1 then the server will assume that the column pointed
   to by password_column contains plaintext passwords and it will
   calculate HA1 strings on the fly.

   If the parameter is set to 0 then the server assumes that the
   database contains HA1 strings directly and will not calculate
   them. If username parameter of credentials contains also
   @domain (some user agents put domain in username parameter),
   then column pointed to by password_column_2 parameter will be
   used instead. This column should also contain HA1 strings but
   they should be calculated including the domain in the username
   parameter (as opposed to password_column which (when
   containing HA1 strings) should always contains HA1 strings
   calculated without domain in username.

   This ensures that the authentication will always work when
   using pre-calculated HA1 string, not depending on the presence
   of the domain in username.

   Default value of this parameter is 0.

   Example 1-6. calculate_ha1 parameter usage
modparam("auth_db", "calculate_ha1", 1)
     _________________________________________________________

1.3.7. use_domain (integer)

   If true (not 0), domain will be also used when looking up in
   the subscriber table. If you have a multi-domain setup, it is
   strongly recommended to turn on this parameter to avoid
   username overlapping between domains.

   IMPORTANT: before turning on this parameter, be sure that the
   domain column in subscriber table is properly populated.

   Default value is "0 (false)".

   Example 1-7. use_domain parameter usage
modparam("auth_db", "use_domain", 1)
     _________________________________________________________

1.3.8. load_credentials (string)

   This parameter specifies of credentials to be fetch from
   database when the authentication is performed. The loaded
   credentials will be stored in AVPs. If the AVP name is not
   specificaly given, it will be used a NAME AVP with the same
   name as the column name.

   Parameter syntax:

     * load_credentials = credential (';' credential)* 
     * credential = (avp_specification '=' column_name) |
       (column_name) 
     * avp_specification = '$avp(' + 'i:'ID | 's:'NAME | alias +
       ')' 

   Default value of this parameter is "rpid".

   Example 1-8. load_credentials parameter usage
# load rpid column into $avp(i:13) and email_address column
# into $avp(s:email_address)
modparam("auth_db", "load_credentials", "$avp(i:13)=rpid;email_address"
)
     _________________________________________________________

1.4. Exported Functions

1.4.1. www_authorize(realm, table)

   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.

   Meaning of the parameters is as follows:

     * realm - 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.
     * table - Table to be used to lookup usernames and passwords
       (usually subscribers table).

   This function can be used from REQUEST_ROUTE.

   Example 1-9. www_authorize usage
...
if (www_authorize("siphub.net", "subscriber")) {
        www_challenge("siphub.net", "1");
};
...
     _________________________________________________________

1.4.2. proxy_authorize(realm, table)

   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.

   Meaning of the parameters is as follows:

     * realm - 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. From header field domain
       will be used as realm.
       The string may contain pseudo variables.
     * table - Table to be used to lookup usernames and passwords
       (usually subscribers table).

   This function can be used from REQUEST_ROUTE.

   Example 1-10. proxy_authorize usage
...
if (!proxy_authorize("", "subscriber)) {
        proxy_challenge("", "1");  # Realm will be autogenerated
};
...
     _________________________________________________________

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

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

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

   3.3. How can I report a bug?

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