LDAP hub

This page has been created as a result of Future of "Extension:LDAP Authentication" sessions held on Wikimedia Hackathon 2017/ (T165270) and SMWCon. It will contain resources about different topics concerning MediaWiki and LDAP.

Basic overview

Process

The stack provides a multi-step process:


#	Description	Track: Network based authentication (NBA)	Track: Form based authentication (FBA )
1	Request for Login	Auth_remoteuser via SessionProvider e.g. `$_SERVER['REMOTE_USER'] = 'someuser@domain.local'` Username and domain are extracted from "REMOTE_USER"	LDAPAuthentication2 together with PluggableAuth via HTML form on "Special:UserLogin" Input fields for username, password and domain
2	Authorization ("group-based restrictions")	LDAPAuthorization together with Auth_remoteuser. After authentication, a check for certain group membership is performed. If it fails, login is aborted. User is not created in database. If it succeeds, user is created if necessary and domain is added to database.	LDAPAuthorization together with PluggableAuth. After authentication a check for certain group membership is performed. If it fails, login is aborted. User is not created in database. If it succeeds, user is created if necessary and domain added to database.
3	Group synchronization	LDAPGroups via UserLoadAfterLoadFromSession hook; username and domain (table `ldap_domains` from LDAPAuthentication2) are read from the database.
4	User info synchronization (e-mail, realname, ...)	LDAPUserInfo via UserLoadAfterLoadFromSession hook; username and domain (table `ldap_domains` from LDAPAuthentication2) are read from the database.

LDAP stack flow

Migrating from old LdapAuthentication

When migrating from "LdapAuthentication" you will need to convert your configuration.

Be aware that you might not need to install all the LDAP Stack extensions to fulfill your use case:

I want to have network based authentication (implicit login) (e.g. by using Apache mod_auth_kerb): You need Extension:Auth_remoteuser
I want to have form-based authentication where my user puts in a username and password that are managed within LDAP: You need Extension:LDAPProvider, Extension:PluggableAuth and Extension:LDAPAuthentication2
I want to restrict login to certain LDAP groups or LDAP attribute values: You need Extension:LDAPProvider and Extension:LDAPAuthorization
I sync user groups managed in LDAP into local wiki user groups: You need Extension:LDAPProvider and Extension:LDAPGroups
I sync user info like "realname" or "email" from LDAP into local wiki user properties: You need Extension:LDAPProvider and Extension:LDAPUserInfo

Working with Groups

Group based login restrictions

The LDAP Stack can be configured to allow only certain user groups to actually log in to the wiki. This means that if a group requirement is not met, a user can not even log into the wiki and no user account will be created in the wiki database. The functionality is implemented in LDAPAuthorization.

There are two configuration options:

Required groups (authorization.rules.groups.required)
Excluded groups (authorization.rules.groups.excluded)

Group synchronization

Local wiki user groups can be automatically synchronized with groups that are set in LDAP. LDAPGroups takes care of this. By default, there are two mechanisms available:

MappedGroups: All local user groups that should be synced must be configured explicitly within a mapping of the form <localusergroup> --> <group-DN>. Groups that are not listed in this mapping will not be synced even if the user is a member on LDAP.
AllGroups: All user groups that a user is assigned to in LDAP will be synced to the local database. Instead of the full group DN, only the CN part of the DN will be used. It is possible to exclude certain groups (e.g., the sysop from being synced).

Mapped groups

A mapping can be set up like this:

"groupsync": {
	"mapping": {
		"mathematicians": "ou=mathematicians,dc=example,dc=com",
		"scientists": "ou=scientists,dc=example,dc=com"
	}

All groups

If all groups should be synced, one must configure

"groupsync": {
	"mechanism": "allgroups"

To prevent certain groups (e.g. "sysop") to be synced, use

"groupsync": {
	"locally-managed": [ "sysop" ]

Versioning

LDAP Stack Extensions are targeted/qualified for MediaWiki LTS releases only.
**However, this table helps to determine which extension-releases to use across all recent versions.**
MediaWiki Release	Recommended Extension Version	Test Status	Latest Test Date
1.35 (LTS)	LDAPxxx_master	Tested	March 2020

Debugging

For debugging, make sure the cache is disabled with $LDAPProviderCacheType = CACHE_NONE;

You can use the following command line scripts to verify your setup:

php extensions/LDAPProvider/maintenance/ShowUserInfo.php --domain YourDomain --username SomeUser
php extensions/LDAPProvider/maintenance/ShowUserGroups.php --domain YourDomain --username SomeUser
php extensions/LDAPProvider/maintenance/CheckLogin.php --domain YourDomain --username SomeUser

Be aware that YourDomain needs to be the exact same value that is specified in the domain config (e.g. the root node of ldapprovider.json).

To enable the debug log you can use

$wgDebugLogGroups['PluggableAuth'] = 
$wgDebugLogGroups['LDAP'] = 
$wgDebugLogGroups['MediaWiki\\Extension\\LDAPProvider\\Client'] = 
$wgDebugLogGroups['LDAPProvider'] = 
$wgDebugLogGroups['LDAPGroups'] = 
$wgDebugLogGroups['LDAPUserInfo'] = 
$wgDebugLogGroups['LDAPAuthentication2'] = 
$wgDebugLogGroups['LDAPAuthorization'] = '/tmp/LDAP.log';

in your LocalSettings.php.

A full example with Docker

See https://github.com/createyourpersonalaccount/openldap-mediawiki/. It is a minimal working example that you can build on.

Related Materials

Manual:Active Directory Integration (PluggableAuth + LDAP Stack)