# &adminguide;

## 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.

## Dependencies

### &osips; 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)

### External Libraries or Applications

The following libraries or applications must be installed before running &osips; with this module loaded:

- none

## Exported Parameters

### `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 &defaultrodb;.

#### `db_url` parameter usage

    modparam("auth_db", "db_url", "&exampledb;")

### `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.

#### `user_column` parameter usage

    modparam("auth_db", "user_column", "user")

### `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.

#### `domain_column` parameter usage

    modparam("auth_db", "domain_column", "domain")

### `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.

#### `password_column` parameter usage

    modparam("auth_db", "password_column", "password")

### `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.

#### `password_column_2` parameter usage

    modparam("auth_db", "password_column_2", "ha1_2")

### `calculate_ha1` (integer)

This parameter tells the server whether it should considered the loaded password (for authentification) as plaintext passwords or a pre-calculated HA1 string.

Possible meanings of this parameter are:

- 1 (calculate HA1) - the loaded password is a plaintext password, so OpenSIPS will internally calculate the HA1. As the passwors will be loaded from the column specified in the password_column parameter, be sure this parameter points to a column holding a plaintext password (by default, this parameter points to ha1 column);

- 0 (do NOT calculate HA1) - the loaded password is an already computed HA1 value, so OpenSIPS does not have do any further computing (for HA1 value). Depending on the presence of a @domain part (some user agents append the domain to the username credentials parameter too), the modules will load the password (pre-computed HA1) from the password_column_2 column (if domain present) or from the password_column column (if domain not present). Usually, most of the UAs do NOT include a domain part in the username credentials 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.

#### `calculate_ha1` parameter usage

    modparam("auth_db", "calculate_ha1", 1)

### `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).

#### `use_domain` parameter usage

    modparam("auth_db", "use_domain", 1)

### `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.

#### `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")

### `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).

#### `skip_version_check` parameter usage

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

## Exported Functions

### `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.

#### `www_authorize` usage

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

### `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.

#### proxy_authorize usage

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