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Extension:PluggableAuth

Issue tracker: #mediawiki-extensions-pluggable-auth
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MediaWiki extensions manual
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 7.1.0 (2024-02-23)
Compatibility policy Snapshots releases along with MediaWiki. Master is not backward compatible.
MediaWiki >= 1.35.0
Composer mediawiki/pluggable-auth
License MIT License
Download
Download extension
Git [?]:
Parameters
  • $wgPluggableAuth_EnableFastLogout
  • $wgPluggableAuth_EnableLocalLogin
  • $wgPluggableAuth_EnableLocalProperties
  • $wgPluggableAuth_EnableAutoLogin
  • $wgPluggableAuth_Config
Hooks used
Hooks provided
Quarterly downloads 920 (Ranked 2nd)
Translate the PluggableAuth extension if it is available at translatewiki.net
Issues Open tasks · Report a bug

The PluggableAuth extension provides a framework for creating authentication and authorization extensions.

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.

The following are the main authentication extensions that can be used with PluggableAuth:

The following authentication extensions also exist, but can only be used with older versions of PluggableAuth:

Authorization is the process of determining whether a particular authenticated user should have access to a particular resource. 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.

In PluggableAuth's case, authorization extensions determine if an authenticated user may proceed with logging in to a wiki. However, the authentication extensions (rather than the authorization extensions) take care of which user groups a user should be authorized for, based on the attributes passed from the identity provider (IdP).

The following authorization extensions can be used with PluggableAuth:

PluggableAuth must be used with one or more authentication plugins and zero or more authorization plugins. If more than one authentication plugin is used, a button for each authentication plugin will be added to the Special:UserLogin page. If a single authentication plugin is used and local login is disabled, the Special:UserLogin page will be bypassed. If no authorization plugins are used, all authenticated users will be authorized to use the wiki.

PluggableAuth defines one important hook: PluggableAuthUserAuthorization . This hook enables authorization plugins to provide code to make an authorization decision. Previously, it also defined the hook PluggableAuthPopulateGroups . This hook was used to augment MediaWiki's group information with that from an external provider, but in version 7.0.0 it was removed and replaced with a function.

Installation

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  • Download and move the extracted PluggableAuth folder to your extensions/ directory.
    Developers and code contributors should install the extension from Git instead, using:cd extensions/
    git clone https://gerrit.wikimedia.org/r/mediawiki/extensions/PluggableAuth
  • Add the following code at the bottom of your LocalSettings.php file: 
    wfLoadExtension( 'PluggableAuth' );
  • The createaccount or autocreateaccount user rights must be granted to all users. See User rights.
  • Configure as required
  • Yes Done – Navigate to Special:Version on your wiki to verify that the extension is successfully installed.
One or more authentication plugins and zero or more authorization plugins must be installed as well.
Versions 6.0 and 7.0.0 of PluggableAuth are significant upgrades. The configuration variable $wgPluggableAuth_Config is required in version 6.0 and later. The plugins must be compatible with the version of PluggableAuth installed.
Compatibility matrix
Plugin PluggableAuth version 7.0.0 or later PluggableAuth version 6.x PluggableAuth version 5.7 or earlier
AuthRemoteUser 1.0.0 - -
Cas 1.0 - -
DiscourseSsoConsumer - 4.0.0 3.0.0
JWTAuth 2.0.0 - -
LDAPAuthentication2 2.0.0 - 1.0.1
NaylorAMS 0.2.0 - 0.1.0
OpenID Connect 7.0.0 6.0.0 5.4.0
PHPBB Auth 4.1.0 4.1.0 4.0.0
Shibboleth 2.0.0 - v1.0.0-rc.1
SimpleSAMLphp 7.0.0 5.0.0 4.5.2
WSOAuth 9.0.0 6.0.0 5.0.0
EmailAuthorization 3.0.0 3.0.0 2.0.0
LDAPAuthorization 2.0.0 - 1.0.0

Configuration

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All versions

[edit]
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.

Version 7.0.0 or later

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Flag Default Description
$wgPluggableAuth_EnableFastLogout false Allow logout without an extra button click to confirm if bypassing the XHR POST logout. Since MediaWiki 1.35 by default (Skin "Vector") the logout is no longer performed by navigating to "Special:UserLogout", but is instead done by an XHR POST request. This is incompatible with the logout process of many external identity providers if performing single logout, so a mechanism was added to allow the old approach, but by default that requires an additional button click to confirm logout. Setting this flag to true will avoid that additional button click.

Version 6.0 or later

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Flag Default Description
$wgPluggableAuth_Config [] An array of arrays containing configuration for the authentication plugins. The keys to the outer array are used as the button labels on Special:UserLogin if no button message is provided in the respective inner array. The valid keys to the inner arrays are:
  • plugin (required) — The name of the authentication plugin
  • buttonLabelMessage (optional) — The system message key, e.g., SSOButtonLabel that lets you add the label at MediaWiki:SSOButtonLabel to be used for the button on Special:UserLogin Note that the message added must be in the instance language since it cannot be localized on wiki.
  • weight — (version 7.1.0 and later) The weight to use to control the placement of the fields, if any, on Special:UserLogin. Sorting is handled by AuthManagerSpecialPage::sortFormDescriptorFields().
  • data — A configuration array to be passed to the authentication plugin. The contents depend upon the authentication plugin. Depending upon the authentication plugin, this may be optional or required.
  • groupsyncs — (version 7.0.0 and later) Configuration array for group syncronization. See details at Group Synchronization below.

Version 5.7 or earlier

[edit]
Flag Default Description
$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.

Group Synchronization

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In version 7.0.0 and later when you are using an authentication plugin that supports retrieval of attributes from the identity provider (currently OpenID Connect, SimpleSAMLphp, WSOAuth, and JWTAuth), it is possible to synchronize groups from the identity provider to MediaWiki groups.

There are two built-in group synchronization algorithms, syncall and mapped, described below. It is also possible for an extension to provide additional custom group synchronization algorithms.

To configure group synchronization, add a groupsyncs array to the $wgPluggableAuth_Config array. That array must contain one or more arrays that specify a group sync to be applied to the attributes retrieved from the identity provider. All group syncs must define a type element, which will have the value syncall, mapped, or the name of a custom group sync. Group syncs may also specify a groupAttributeDelimiter that can be used to explode multi-valued attributes.

syncallgroup sync

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The syncall group sync will synchronize all groups in the relevant attributes sent from the identity provider to MediaWiki groups. It supports the following additional configuration elements:

  • groupAttributeName (default: "groups"): The name of the attribute that contains the groups identified for the user by the identity provider. This can be a single string value or can be an array. If it is an array, it must contain an element, path, that is an array of strings that form a path through the attributes to the group values.

It may also contain an element, prefix, that is a string to prepend to the name of each group found in that path.

  • locallyManaged (default: [ "sysop" ]): An array of strings that are the names of groups that will be managed by MediaWiki rather than the identity provider, so they should not be removed if they are not in the array of groups sent by the identity provider.
  • filterPrefix (default: ‘’): A prefix to prepend to all groups found by this group sync. If provided, only groups already assigned to the user in MediaWiki that begin with this prefix will be removed and replaced with the groups sent by the identity provider; if it is not provided, all groups except those in the locallyManaged array will be removed and replaced by those sent by the identity provider.
  • onlySyncExisting (default: false): Only add groups that are already known to MediaWiki.
  • groupNameModificationCallback (optional): A callback that will be applied to each group name.

Example

[edit]
$wgPluggableAuth_Config = [
  "My Login" => [
    'plugin' => '...',
    'data' => [
      ...
    ],
    'groupsyncs' => [
      [
        'type' => 'syncall',
        'locallyManaged' => [ 'sysop', 'bureaucrat' ],
        'filterPrefix' => 'oidc_',
        'groupAttributeName' => [
          [
            'path' => ['realm_access', 'roles'],
            'prefix' => 'global_',
          ],
          [
            'path' => ['resource_access', 'account', 'roles'],
          ]
        ],
        'groupNameModificationCallback' => static function ( $origGroupName ) {
          return str_replace( 'globex', 'acme', $origGroupName );
        }
      ]
    ]
  ]
];

mappedgroup sync

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The mapped groupsync is used when only a subset of groups sent from the identity provider should be synchronized with the wiki. Only groups that are mentioned in the mapping are affected by the mapping. It supports the following additional configuration elements:

  • map: An array containing the mapping to MediaWiki groups from identity provider attributes. Each top level array index is the name of a MediaWiki group. The array elements corresponding to those indices contain an array of elements each with an attribute name as the array index and a string value or an array of string values as the value, indicating the attribute values that will map to that group.
  • addOnlyGroups (default: []): An array of MediaWiki groups that should only be added to the user if they appear in the attributes sent from the identity provider, not removed if they do not appear.

Example

[edit]
$wgPluggableAuth_Config = [
  "My Login" => [
    'plugin' => '...',
    'data' => [
      ...
    ],
    'groupsyncs' => [
      [
        'type' => 'mapped',
        'map' => [
          'industry' => [ 'groups' => 'Professional Member' ],
          'student' => [ 'groups' => 'Student Member' ],
          'member' => [ 'groups' => [ 'Professional Member', 'Student Member'  ] ],
          'staff' => [ 'groups' => 'Staff' ]
        ]
      ]
    ]
  ]
];

Developer notes

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Creating an authentication plugin

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Version 6.0 and later:

  • Authentication plugins subclass the abstract MediaWiki\Extension\PluggableAuth\PluggableAuth class provided by PluggableAuth.
  • In version 6.0 and later, an authentication plugin must specify at attributes section in extension.json. For example:
"attributes": {
   "PluggableAuth": {
      "OpenIDConnect": {
         "class": "MediaWiki\\Extension\\OpenIDConnect\\OpenIDConnect",
         "services": [
            "MainConfig",
            "AuthManager",
            "OpenIDConnectStore"
         ]
      }
   }
},

Version 5.7 and earlier:

  • Authentication plugins subclass the abstract PluggableAuth class provided by PluggableAuth.
  • An authentication plugin must set $PluggableAuth_Class to the name of this subclass.

The authentication plugin subclass must implement the following methods:

public function authenticate( ?int &$id, ?string &$username, ?string &$realname, ?string &$email, ?string &$errorMessage ): bool;

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

public function saveExtraAttributes( int $id ): void

  • 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( UserIdentity &$user ): void

  • 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

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The Special:UserLogin page will only be displayed to the user during authentication if user interaction is required.

That is, if there is only a single configured authentication provider, its authentication plugin does not add extra fields to the Special:UserLogin form using the PluggableAuth::getExtraLoginFields() static function (or $wgPluggableAuth_ExtraLoginFields in version 5.7 or earlier), and 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.

If no such library exists and you need to implement the authentication mechanism from scratch, the redirect should not go to Special:UserLogin. Instead, it should go to a custom, unlisted special page based on PluggableAuthLogin.php. Finally, if there is no user input required by the user as part of authentication from either Special:UserLogin or the remote authentication system, clicking on the Log in link will simply re-render the current page in a logged in state.

If an authentication plugin adds extra fields to the Special:UserLogin form using the PluggableAuth::getExtraLoginFields() static function (or $wgPluggableAuth_ExtraLoginFields in version 5.7 or earlier), the fields can be accessed in the authenticate() function in an authentication plugin as follows: 

...
$authManager = MediaWikiServices::getInstance()->getAuthManager();
$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.

Creating an authorization plugin

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

function authorize( UserIdentity $user, bool &$authorized ): void

  • $user is the UserIdentity object for the user requesting authorization
  • $authorized must be set to true if the user is authorized and false otherwise.

Enlarge the login buttons to fit longer button texts

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The patch enlarges the login buttons (the standard Login button and the Extension:OpenIDConnect's Login button) to display the complete texts on the buttons, even if your texts are longer than usual.

In LocalSettings.php add: 

# https://www.mediawiki.org/w/index.php?title=Topic:Xx8ol75kyh1qejp8
# How to modify the Login-Page
$GLOBALS['wgHooks']['BeforePageDisplay'][] = function( OutputPage &$out, Skin &$skin ) {
        $style = <<<EOT
            <style type="text/css">
                    button#wpLoginAttempt {
                            white-space: normal;
                            word-wrap: break-word;
                            height: auto !important;
                    }

                    button#mw-input-pluggableauthlogin0 {
                            background-color: salmon !important;
                            border-color: salmon !important;
                            white-space: normal;
                            word-wrap: break-word;
                            height: auto !important;
                    }
            </style>
EOT;

        $out->addHeadItem( 'change-login-button', $style );
        return true;
};

Release notes

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Version 7.1.0
  • Add weight parameter to config to control the placement of fields on Special:UserLogin
Version 7.0.0
  • Add group population framework (migrated from SimpleSAMLphp functionality)
  • Made config case insensitive
  • Converted group population from a hook to a function
  • Code improvements
  • Bug fixes:
    • T333415: LDAP login does not work when local login is enabled
    • T334083: Problem with auto-creation of LDAP user in the wiki in case of the first login
    • T334950: Username missing in "onPluggableAuthUserAuthorization" hook
    • T305031: Error when logging out via API
    • T322828: Don't store return to URL as an auth/session secret
Version 6.3
  • Fixed MW 1.35 incompatibility in deauthenticate
Version 6.2
  • added compatibility with MW 1.39
    • Switch from deprecated PersonalUrls hook to SkinTemplateNavigation::Universal
  • Only set real name if it is not null
  • Use setter and getter for user's real name
Version 6.1
  • restored backward compatibility with MW 1.35 (T308865)
Version 6.0
  • Support multiple authentication plugins using $wgPluggableAuth_Config
  • Requires MediaWiki 1.35+
  • Drop support for the following configuration variables:
    • $wgPluggableAuth_ButtonLabelMessage (use the buttonLabelMessage field in the corresponding $wgPluggableAuth_Config entry)
    • $wgPluggableAuth_ButtonLabel (use the index of the corresponding $wgPluggableAuth_Config entry)
    • $wgPluggableAuth_ExtraLoginFields (use static function in PluggableAuth class)
    • $wgPluggableAuth_Class (now specified by an attribute in the authentication plugin's extension.json and referred to by the plugin field in the corresponding $wgPluggableAuth_Config entry)
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
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