Open main menu

Extension:PluggableAuth

MediaWiki extensions manual
OOjs UI icon advanced.svg
PluggableAuth
Release status: stable
px
Implementation User identity , User rights , Hook
Description Provides framework for authentication and authorization extensions.
Author(s) Cindy Cicalese (cindy.cicalesetalk)
Latest version 5.7 (2018-11-26)
Compatibility policy master
MediaWiki 1.27+
License MIT License
Download
  • $wgPluggableAuth_EnableAutoLogin
  • $wgPluggableAuth_EnableLocalLogin
  • $wgPluggableAuth_EnableLocalProperties
  • $wgPluggableAuth_ButtonLabelMessage
  • $wgPluggableAuth_ButtonLabel
  • $wgPluggableAuth_ExtraLoginFields
  • $wgPluggableAuth_Class
Translate the PluggableAuth extension if it is available at translatewiki.net
Check usage and version matrix.
Issues Open tasks · Report a bug

The PluggableAuth extension provides a framework for creating authentication and authorization extensions. PluggableAuth provides the shared code necessary to implement these extensions, which are referred to below as authentication plugins and authorization plugins. PluggableAuth must be used with exactly one authentication plugin and zero or more authorization plugins.

Authentication is the process of proving that a user is who they say they are. This may be done, for example, by providing a username and password or some token or biometric. Authorization is the process of determining whether a particular authenticated user should have access to a particular resource - in this case a wiki. This may be done, for example, by checking a list of authorized email addresses or checking values of user attributes provided by an identity server.

PluggableAuth is especially useful for use with enterprise authentication servers accessed through layered mechanisms such as SAML, LDAP, or OpenID Connect. PluggableAuth authentication plugins that provide this service include Extension:SimpleSAMLphp, Extension:LDAPAuthentication2, and Extension:OpenID Connect. One PluggableAuth authentication plugin must be enabled for PluggableAuth to function.

PluggableAuth provides an authorization hook, PluggableAuthUserAuthorization, that enables authorization plugins to provide code to make an authorization decision. PluggableAuth authorization plugins include Extension:Email Authorization and Extension:LDAP Authorization. PluggableAuth authorization plugins are optional. If an authorization plugin is not enabled, all authenticated users will be authorized to use the wiki.


In addition, in order to augment MediaWiki's group information with that from an external provider, PluggableAuth provides the PluggableAuthPopulateGroups hook.

InstallationEdit

  • Download and place the file(s) in a directory called PluggableAuth in your extensions/ folder.
  • Add the following code at the bottom of your LocalSettings.php:
    wfLoadExtension( 'PluggableAuth' );
    
  • The createaccount or autocreateaccount user rights must be granted to all users. See User rights.
  • Configure as required
  •   Done – Navigate to Special:Version on your wiki to verify that the extension is successfully installed.

ConfigurationEdit

Flag Default Description
$wgPluggableAuth_EnableAutoLogin false Should login occur automatically when a user visits the wiki?
$wgPluggableAuth_EnableLocalLogin false Should user also be presented with username/password fields on the login page to allow local password-based login to the wiki?
$wgPluggableAuth_EnableLocalProperties false If true, users can edit their email address and real name on the wiki. If false, the default, they cannot do so. Note that, if you rely on email address and/or real name returned from the authentication provider in any way, you should leave this setting at its default value.

After the call to authenticate() , PluggableAuth checks to see if the real name or email address returned are different from those saved in the wiki database. If either is different, it checks to see if this setting is true. If so, this is understood by PluggableAuth to indicate that the real name and email address are managed in the wiki on the Special:Preferences page, Otherwise, the real name and email address are managed by the authentication provider, so the new real name and email address values are saved to the wiki database. That is, if this setting is false, any changes to the real name or email address at the remote authentication provider will overwrite the local values when the user logs in.

$wgPluggableAuth_ButtonLabelMessage no default value If set, the name of a message that will be used for the label of the login button on the Special:UserLogin form. This is useful if an authentication plugin will be showing the Special:UserLogin form to the user and needs to customize the button label with a localizable Message. If not set and if no value is set for $wgPluggableAuth_ButtonLabelMessage, the value of the pluggableauth-loginbutton-label message, which has a default value of "Log In With PluggableAuth" will be used. To override this value you can edit the page MediaWiki:Pluggableauth-loginbutton-label and its language variants. This configuration variable is usually set, if at all, by authentication plugins and not by wiki site administrators. If set by a wiki site administrator, the relevant message pages in the MediaWiki namespace will need to be created with the localized message values.
$wgPluggableAuth_ButtonLabel null If $wgPluggableAuth_ButtonLabelMessage is not set and $wgPluggableAuth_ButtonLabel is set to a string value, this string value will be used as the label of the login button on the Special:UserLogin form. This allows a wiki site administrator to set the label if a localizable Message is not provided by an authentication plugin. Note that this string is NOT localizable.
$wgPluggableAuth_ExtraLoginFields [] An array of extra fields to be added to the login form at Special:UserLogin. See the documentation for AuthenticationRequest:getFieldInfo() for the format of the array. This configuration variable may be set by authentication plugins and should not be set by wiki site administrators.
$wgPluggableAuth_Class no default value The name of a class that extends the abstract PluggableAuth class to provide authentication. This configuration variable must be set by authentication plugins and should not be set by wiki site administrators.

Developer Notes - Creating an Authentication PluginEdit

Authentication plugins subclass the abstract PluggableAuth class provided by PluggableAuth. An authentication plugin must set $PluggableAuth_Class to the name of this subclass and must implement the following functions:

public function authenticate( &$id, &$username, &$realname, &$email, &$errorMessage )

  • Called to authenticate the user.
  • The parameters are used to return the user id, username, real name, and email address of the authenticated user and, if the user cannot be authenticated, an optional error message. $id is an integer and the remaining parameters are all strings. If the user cannot be authenticated and no value is set for $errorMessage, a default error message is displayed.
  • $id must be set to null if the user is new, in which case PluggableAuth will add the user to the database.
  • Must return true if the user has been authenticated and false otherwise.
  • If the return to URL, the name of the page, or the query parameters from the page that login was initiated from are necessary in the authenticate() function, they may be accessed as follows:
use \MediaWiki\Auth\AuthManager;

...

$authManager = AuthManager::singleton();
$returnToUrl = $authManager->getAuthenticationSessionData(
    PluggableAuthLogin::RETURNTOURL_SESSION_KEY
);
$returnToPage = $authManager->getAuthenticationSessionData(
    PluggableAuthLogin::RETURNTOPAGE_SESSION_KEY
);
$returnToQuery = $authManager->getAuthenticationSessionData(
    PluggableAuthLogin::RETURNTOQUERY_SESSION_KEY
);

public function saveExtraAttributes( $id )

  • Called after a new user has been authenticated and added to the database to add any additional information to the database required by the authentication mechanism.

public function deauthenticate( User &$user )

  • Called when the user logs out to notify the identity provider, if necessary, that cleanup such as removing the user's session should be done.

Special:UserLogin and Extra Login FieldsEdit

The Special:UserLogin page will only be displayed to the user during authentication if there are fields on that form that the user must fill in. That is, if an authentication plugin does not add extra fields to the Special:UserLogin form using $wgPluggableAuth_ExtraLoginFields and if local login (which enables the username and password fields on the Special:UserLogin form) is not enabled by a site administrator using $wgPluggablAuth_EnableLocalLogin, the Special:UserLogin page will not be displayed. Even if Special:UserLogin is not displayed, it may be necessary for an authentication plugin to gather user input using a web page provided by an enterprise authentication system. This would be accomplished by a redirect, often from within the authentication library used by the authentication plugin. Finally, if there is no user input required by the user as part of authentication from either Special:UserLogin or the remote authentication system, clcking on the Log in link sill simply re-render the current page in a logged in state.

If an authentication plugin adds extra fields to the Special:UserLogin form using $wgPluggableAuth_ExtraLoginFields, the fields can be accessed in the authenticate() function in an authentication plugin as follows:

use MediaWiki\Auth\AuthManager;
...
$authManager = AuthManager::singleton();
$extraLoginFields = $authManager->getAuthenticationSessionData(
    PluggableAuthLogin::EXTRALOGINFIELDS_SESSION_KEY
);

This will return an array of field values indexed by the name of the field from the field descriptor array.

Developer Notes - Creating an Authorization PluginEdit

Authorization hooks use the PluggableAuthUserAuthorization hook to register an implementation of the following function:


function authorize( User $user, &$authorized )

  • $user is the User object for the user requesting authorization
  • $authorized must be set to true if the user is authorized and false otherwise.
  • Return true to call other authorization hook implementations and false to skip them.

Release NotesEdit

Version 5.7
  • Added error message when there is a rare fatal session error
Version 5.6
  • Fixed autologin so it returns to the correct page after authentication.
Version 5.5
  • Fixed issue with PluggableAuthPopulateGroups hook.
Version 5.4
  • Added $wgPluggableAuth_ButtonLabelMessage and $wgPluggableAuth_ButtonLabel.
  • Coding style fixes.
Version 5.3
  • Added $wgPluggableAuth_ExtraLoginFields.
Version 5.2
  • Converted auto login to PHP from JavaScript.
Version 5.1
  • Added PluggableAuthPopulateGroups hook. Thank you to Poikilotherm for contributing this functionality.
Version 5.0
  • Added $wgPluggableAuth_EnableLocalProperties and removed use of editmyprivateinfo
  • Added debug statement when returntourl is not set
Version 4.2
  • Fixed exception when returntoquery is undefined.
Version 4.1
  • Added session variables to hold the name of the page and the query parameters of the page from which login was initiated for use in authenticate()
Version 4.0
  • Added optional error message to authenticate()
  • Bumped version number to synchronize with SimpleSAMLphp and OpenIDConnect extensions
Version 2.2
  • Confirm email addresses coming from external authentication sources
Version 2.1
  • Update file naming conventions
Version 2.0
  • Almost completely rewritten to support the new MediaWiki 1.27 authentication and session management framework
  • Switched to new extension registration
  • Configuration variable names changed to add $wg prefix
  • $PluggableAuth_Timeout removed
  • $PluggableAuth_AutoLogin renamed to $wgPluggableAuth_EnableAutoLogin
  • $wgPluggableAuth_EnableLocalLogin added to support local password-based login to the wiki in addition to PluggableAuth
Version 1.2
  • Moved the addition of a new user to the wiki database to after successful authorization of the user
  • Added editmyprivateinfo check
Version 1.1
  • Added call to logout when session times out to ensure that the deauthenticate function in implementing classes gets called
Version 1.0
  • Initial version

See alsoEdit