
Auth_db Module

Jan Janak

   FhG Fokus

Jakob Schlyter

Edited by

Jan Janak

   Copyright © 2002, 2003 FhG FOKUS
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   Table of Contents
   1. User's Guide

        1.1. Overview
        1.2. Dependencies
        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. rpid_column (string)
              1.3.6. calculate_ha1 (integer)
              1.3.7. password_column_2 (string)
              1.3.8. use_rpid (integer)

        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 usage
   1-3. domain_column usage
   1-4. password_column usage
   1-5. rpid_column usage
   1-6. calculate_ha1usage
   1-7. password_column_2 usage
   1-8. use_rpidusage
   1-9. www_authorize usage
   1-10. proxy_authorize usage
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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.
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1.2. Dependencies

   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)
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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
   sql://username:password@host:port/database. For dbtext module
   (which stores data in plaintex files) it is directory in which
   the database resides.

   Default value is "sql://serro:47serro11@localhost/ser".

   Example 1-1. db_url parameter usage
modparam("auth_db", "db_url", "sql://foo:bar@foobar.org/ser")
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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 usage
modparam("auth_db", "user_column", "user")
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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 usage
modparam("auth_db", "domain_column", "domain")
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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 usage
modparam("auth_db", "password_column", "password")
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1.3.5. rpid_column (string)

   This is the name of the column holding information for the
   Remote-Party-ID header field. Default value is fine for most
   people. Use the parameter if you really need to change it.

   Default value is "rpid".

   Example 1-5. rpid_column usage
modparam("auth_db", "rpid_column", "remote_party_id")
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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_ha1usage
modparam("auth_db", "calculate_ha1", 1)
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1.3.7. 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 1-7. password_column_2 usage
modparam("auth_db", "password_column_2", "ha1_2")
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1.3.8. use_rpid (integer)

   This parameter specifies whether the server should fetch a
   value for the Remote-Party-ID header field from the database.

   If the parameter is set to 1 the server expects to find a
   value for this header in the column specified by the
   rpid_column parameter.

   Default value of this parameter is 0.

   Example 1-8. use_rpidusage
modparam("auth_db", "use_rpid", 1)
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1.4. Exported Functions

1.4.1. www_authorize(realm, table)

   The function verifies credencials according to RFC2617. If the
   credentials are verified sucessfully 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. Usualy 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.
     * table - Table to be used to lookup usernames and passwords
       (usualy subscribers table).

   Example 1-9. www_authorize usage
...
if (www_authorize("iptel.org", "subscriber")) {
    www_challenge("iptel.org", "1");
};
...
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1.4.2. proxy_authorize(realm, table)

   The function verifies credencials according to RFC2617. If the
   credentials are verified sucessfully 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. Usualy 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.
     * table - Table to be used to lookup usernames and passwords
       (usualy subscribers table).

   Example 1-10. proxy_authorize usage
...
if (!proxy_authorize("", "subscriber)) {
    proxy_challenge("", "1");  # Realm will be autogenerated
};
...
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Chapter 2. Developer's Guide

   To be done.
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Chapter 3. Frequently Asked Questions

   3.1. What is the meaning of life ?

   3.1. What is the meaning of life ?

   42
