Auth_db Module

Jan Janak

FhG Fokus

Jakob Schlyter

Bogdan-Andrei Iancu

Edited by

Jan Janak

Revision History
Revision $Revision: 8740 $$Date: 2012-02-22 18:29:43 +0100 (Wed, 22 Feb 2012) $

Table of Contents

1. Admin Guide
1.1. Overview
1.2. Dependencies
1.2.1. OpenSIPS 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)
1.3.9. skip_version_check (int)
1.4. Exported Functions
1.4.1. www_authorize(realm, table)
1.4.2. proxy_authorize(realm, table)

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. skip_version_check parameter usage
1.10. www_authorize usage
1.11. proxy_authorize usage

Chapter 1. Admin 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. OpenSIPS 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 OpenSIPS 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://opensipsro:opensipsro@localhost/opensips”.

Example 1.1. db_url parameter usage

modparam("auth_db", "db_url", "dbdriver://username:password@dbhost/dbname")

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 the server whether it should use plaintext passwords or a pre-calculated HA1 string for authentification.

If the parameter is set to 1 and the username parameter of credentials contains also “@domain” (some user agents append the domain to the username parameter), then the server will use the HA1 values from the column specified in the “password_column_2” parameter. If the username parameter doesn't contain a domain, the server will use the HA1 values from the column given in the “password_column”parameter.

If the parameter is set to 0 then the HA1 value will be calculated from the column specified in the “password_column” parameter.

The “password_column_2” column contains also 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 contain HA1 strings calculated without domain in username.

This ensures that the authentication will always work when using pre-calculated HA1 strings, 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 credentials to be fetched 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(' + NAME + ')'

Default value of this parameter is “rpid”.

Example 1.8. load_credentials parameter usage

# load rpid column into $avp(13) and email_address column
# into $avp(email_address)
modparam("auth_db", "load_credentials", "$avp(13)=rpid;email_address")

1.3.9. skip_version_check (int)

This parameter specifies not to check the auth table version. This parameter should be set when a custom authentication table is used.

Default value is “0 (false)”.

Example 1.9. skip_version_check parameter usage

modparam("auth_db", "skip_version_check", 1)
		

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.

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;

  • -2 (invalid password) - valid user, but wrong password;

  • -1 (invalid user) - authentication user does not exist.

Meaning of the parameters is as follows:

  • realm - Realm is an opaque string that the user agent should present to the user so it 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 1.10. 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.

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;

  • -2 (invalid password) - valid user, but wrong password;

  • -1 (invalid user) - authentication user does not exist.

Meaning of the parameters is as follows:

  • realm - Realm is an opaque string that the user agent should present to the user so it 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 1.11. proxy_authorize usage

...
if (!proxy_authorize("", "subscriber)) {
	proxy_challenge("", "1");  # Realm will be autogenerated
};
...