Extension:Shibboleth
This extension requires the PluggableAuth extension to be installed first. Release status: stable |
|
|---|---|
| Implementation | User identity |
| Description | Uses the PluggableAuth extension to provide authentication using Shibboleth. |
| Author(s) | |
| Latest version | 2.0.0 (2024-10-14) |
| MediaWiki | 1.39+ |
| PHP | 7.1+ |
| License | MIT License |
| Download | GitHub: README |
|
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| Quarterly downloads | 2 (Ranked 131st) |
The Shibboleth extension uses the PluggableAuth extension to provide authentication using Shibboleth Apache module.
Installation
[edit]- Download and place the file(s) in a directory called
Shibbolethin yourextensions/folder. - Add the following code at the bottom of your LocalSettings.php:
wfLoadExtension( 'Shibboleth' );
- Configure as required
- Done! Navigate to Special:Version on your wiki to verify that the extension is successfully installed.
Configure
[edit]Values must be provided for the following mandatory configuration variables:
| Flag | Default | Description |
|---|---|---|
| $wgShibboleth_Username | eppn | The name of the attribute to be used for the user's username. |
| $wgShibboleth_Email | The name of the attribute to be used for the user's email address. | |
| $wgShibboleth_DisplayName | displayName | The name of the attribute to be used for the user's real name. |
| $wgShibboleth_Logout_Base_Url | no default value | Single Logout (SLO) base URL |
| $wgShibboleth_Logout_Target_Url | no default value | Single Logout (SLO) target URL |
In addition, the following optional configuration variable is provided:
| Flag | Default | Description |
|---|---|---|
| $wgShibboleth_GroupMap | null | Mapping from SAML attributes to MediaWiki groups, see example below. No group mapping is performed if $wgShibboleth_GroupMap is null. |
| $wgShibboleth_GroupMap_attr_may_be_empty | false | Allow empty group mapping attribute. Is you use an entitlement for group mapping this is needed to enable people without any entitlement to login. |
| $wgShibboleth_DisplayNameFormatString | null | Allows a custom format string which creates the display name (see vsprintf()) |
Display name
[edit]You can either use a single SAML attribute as display name or multiple attributes:
$wgShibboleth_DisplayName = 'displayName';
$wgShibboleth_DisplayName = ['givenName', 'sn'];
If you define multiple attributes their values are concatenated with spaces. If you still want more you can use a user defined format string:
$wgShibboleth_DisplayName = ["displayName", "mail"];
$wgShibboleth_DisplayNameFormatString = "%s <%s>";
This results in
Christopher Odenbach <odenbach@uni-paderborn.de>
Group mapping
[edit]Use case: your SAML IdP reads groups from LDAP or Database and stores this information inside an attribute of the SAML response. You want to use this to map MediaWiki groups to users belonging to some known groups given by your IdP.
Example:
- Your IdP sends an attribute named "groups" with a list of names like "administrator", "student", "teacher", ... in the SAML response after authentication.
- All users that have the value "administrator" in the "groups" attribute shall be mapped to the MediaWiki "sysop" group to give them admin rights within your MediaWiki instance.
- For some reason you may also want to grant sysop rights to someone with a special pairwise-id but who is not in the administrator group.
- Create a group map in your LocalSettings.php as follows:
$wgShibboleth_GroupMap = [
'groups' => [
'administrator' => 'sysop',
],
'pairwise-id' => [
'OTCROY5S7ZWGWYD6Z7EAXRXMA44YMW5S@uni-paderborn.de' => 'sysop',
],
];
So the variable contains a list of SAML attributes ('groups' and 'pairwise-id' here). Each of the attributes points to a list of key-value pairs where the key is a string or a regular expression of the attribute's value, and the value contains the mediawiki group which should be assigned if the attribute contains the string or regex.
If you want to use a regex, just enclose it in slashes, e.g.
$wgShibboleth_GroupMap = [
'entitlement' => [
'/urn:geant:dfn.de:idm.nrw:[^:]+:role:rid=10000001-9:rname=DaSi_Expert/' => 'sysop',
],
'pairwise-id' => [
'GVKE7A3O4XXCDMKAA4XES5Z7SRMDBDNG@uni-paderborn.de' => 'sysop',
'gxzcf8mttg6jsd0mprx28l8kmjox489ltgfatn0hjaooqnxn5bgdtot5zpz6uzzv@rwth-aachen.de' => 'sysop',
],
];
In this example every person with an entitlement from any university with the role DaSi_Expert gets the sysop role, and also two other explicit people.
You can come up with rather complex mappings that fit your needs.
Hint: If a user belongs to a MediaWiki group that is no longer mapped to that user (for example, by losing the group membership in the SAML user data source), the user will be removed from that MediaWiki group at next log in. In that way you can mass remove groups from SAML and their memberships, too - just scramble the mapping values so they don't match the SAML response, but don't mess up the MediaWiki group name.
Single Logout (SLO)
[edit]Shibboleth Single Logout (SLO) URL structure:
$wgShibboleth_Logout_Base_Url . Shibboleth.sso/Logout?return= . $wgShibboleth_Logout_Target_Url
https://wiki.example.org/Shibboleth.sso/Logout?return=https://wiki.example.org/index.php