Extension:PluggableAuth

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 or OpenID Connect. PluggableAuth authentication plugins that provide this service include Extension:SimpleSAMLphp and Extension:OpenID Connect.

PluggableAuth provides an authorization hook, PluggableAuthUserAuthorization, that authorization plugins must provide an implementation for. PluggableAuth authorization plugins include Extension:Email Authorization and Extension:LDAP Authorization.

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

Developer Notes - Creating an Authentication Plugin
Authentication plugins subclass the abstract  class provided by PluggableAuth. An authentication plugin must set  to the name of this subclass and must implement the following functions:


 * 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.  is an integer and the remaining parameters are all strings. If the user cannot be authenticated and no value is set for , a default error message is displayed.
 * must be set to  if the user is new, in which case   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:


 * 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.


 * 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 Fields
The  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  form using   and if local login (which enables the username and password fields on the   form) is not enabled by a site administrator using , the   page will not be displayed. Even if  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  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  form using , the fields can be accessed in the   function in an authentication plugin as follows: 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 Plugin
Authorization hooks use the PluggableAuthUserAuthorization hook to register an implementation of the following function:


 * is the User object for the user requesting authorization
 * 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 Notes

 * 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  hook.


 * Version 5.4
 * Added  and.
 * Coding style fixes.


 * Version 5.3
 * Added.


 * Version 5.2
 * Converted auto login to PHP from JavaScript.


 * Version 5.1
 * Added  hook. Thank you to Poikilotherm for contributing this functionality.


 * Version 5.0
 * Added  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
 * removed
 * renamed to
 * 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   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