Extension:AccessControl

The AccessControl extension allows to restrict access to specific pages based on internal groups or group lists from userspace.

Rationale
MediaWiki in default state is not designed as a Content Management System (CMS), but when used as a corporate or school intranet it is required to protect sensitive data. AccessControl has been developed for this purpose.

The first version of this extension (1.x) was based on the original Extension:Group Based Access Control, but without bugs which original had.

How this extension meets the requirements for site security?

 * Atom/RSS feeds & Diff & revision links : Page content is protected, but when opening a page from history, a piece of raw content will appear in this. If tag "accesscontrol" was placed at the beginning, a potential attacker may be able to obtain information about names of contributing users!


 * Listings & search : Unless otherwise noted, if there is any page with protected content in search results, the user is redirected away. Since version of extension 2.5, searching may be allowed too. But it should be borne in mind that the displayed search results can compromise sensitive data. Therefore, do not write to your wiki such sensitive information as password, that could be obtained throught a fulltext searching, if is allowed search in contents of pages protected through a AccessControl!


 * Inclusion/transclusion & related rights and other extensions: Page containing the AccessControl tag or includes another page protected by the AccessControl tag, is secure. Tag AccessControl is searched in raw wiki code - before conversion to HTML.


 * Redirects: The problem with redirection was repaired in version 1.1


 * API and action links: For each anonymous user the action class is automatically set to false, besides view attribute for unprotected pages. Allowed actions for the authorized user depends on the permissions settings of mediawiki and his username listed in the access list which pages will use.


 * Edit Section and Watching Pages: Options are available only to registered user. If user is logged and member from the security access list.


 * Files & Images : WARNING: The extension AccessControl does not protect files against direct access via URL! If files can not be publicly available, must be protect at the server level!


 * XML export (Special page Export) : WARNING: AccessControl version < 2.0, was based on the hook, which was not protected from MediaWiki side before exporting in a raw form code the page. Therefore, if you use version AccessControl < 2.0, you must prohibit the special page for export the pages from MediaWiki.


 * Author backdoor : Extension AccessControl have not any backdoor!


 * Caching : I recommend to turn off caching. See the previous paragraphs

More info about potential problems regarding security is on page Security issues with authorization extensions.

Features

 * Easy to setup and simple to use.
 * No patches, real extension.
 * Unlimited number of groups.
 * Dual mode access control:
 * View control.
 * Edit control, including restrictions on manual edit access when using action=edit in the URL.
 * User groups may use any namespace.
 * Namespaces with group lists may be protected by another extension.
 * MediaWiki sysop-Group may view and edit the protected pages.
 * Controlled by extension variable
 * Access may be granted to multiple groups
 * Read only access may be granted to both groups and individual users.
 * Unauthorized users can use search feature only if is it allowed. See How this extension meets the requirements for site security?.

Step 1: Local Settings File
NB : See discussion
 * add the following lines to the bottom of your LocalSettings.php:
 * add a namespace to the LocalSettings.php file for the purpose of creating groups.
 * See Manual:Using_custom_namespaces for more information.


 * Check (and maybe edit) the settings in AccessControl.php:

Step 2: Create User Groups
User groups are simply standard wiki pages that are part of a namespace other than the default namespace. For ease of use, it is suggested that a specific custom namespace be created for the explicit purpose of managing access control list pages.
 * Create a Wiki-Page with a users list in any namespace
 * It is not sufficient to simply create a page with a colon in the name, this extension requires the use of a namespace and one or more pages within namespaces
 * Page Name Example: My:Group
 * The namespace is My
 * The group page is Group
 * This is the name of usergroup
 * Users are added to the group in a bulletlist
 * Page Content Example
 * Presume that the namespace IT exists
 * Create a page in the namespace titled "Department"
 * Create users "John Doe" and "Jane Doe" in the group. The group information is contained on the page "Department".
 * Each user name appears as a list item.


 * User from a group, which have appended string "(ro)" to the name can only read protected Article, but can't edit it. For other group of users you can create memberlist with name Department too, but in other namespace.


 * Tips: To protect namespace IT you can use for example Extension:Lockdown, but you can use element accesscontrol to protect it itself.

Step 3: Additional Access Control

 * It depends on localization, your MediaWiki needs pages created to which anonymous or unauthorized users will be redirected. You have create them in advance, because some of them can't access pages from another page.
 * The safety of the page provides accesscontrol element. And his content. If there isn't any or is empty the page is free accessible for logged users (they can read and edit page). No logged or annonymous user can only read the page.
 * Members from groups in accesscontrol element can edit page, only if the group title in list doesn't have added string "(ro)", or if they don't have set readonly access in their user grouplist.
 * By default the variable  is set to true - members from  'sysop'  group can edit usergroups pages in any namespace.


 * Example tag code :

In this example all users from the groups "Administrators", "IT:Department" and "Sales" can read the page but only the users from "Administrators" group (if exists) and John Doe from "IT:Deparment" usergroup can edit it.

Usage on Pages to Control Access
That is for the installation. To restrict access on a page for specific usergroups, just include the names of the allowed usergroups (separated by commas) as the content of accesscontrol tag in the top of the content page.

Attention
Version 2.5 is strongly recommended to be used.

For version < 2.3

 * There was problem in function fromTemplate, it caused that the extension AccessControl did not accept tags from included pages or templates. Actualization is recommend!

For version >= 2.0

 * On page may be accepted only one accesscontrol elements.
 * If the user is a member of multiple groups, so that takes precedence, which gives greater rights him.
 * MediaWiki before 1.21 This extension uses a mediawiki hook that is called whenever a search result is displayed. This means that a page that has an ACL will trigger an "Access Denied" message for end users who happen to search for text contained in a protected page. A simple solution is to put pages that require AccessControl into another NameSpace and then disable searching for that NameSpace. All though this isn't really a bug, it is undesirable behavior. Click here for an example showing a work around.

For version <= 1.3

 * Groups from MediaWiki must be in not localized form! In ex.  'sysop'  not  'Správce' , etc.
 * On page may be more accesscontrol elements. Access is accepted for groups from all.tags
 * Anonymous user has not access on pages protected by accesscontrol elements
 * Pages without protection can anonymous user only read
 * Logged user has access on protected page only when he is member of any group with access rights on page
 * If is set in extension script variable  on true, have members from group  'sysop'  edit access on page always

Example
See an example of this add-on in action at: http://support.dce.felk.cvut.cz/mediawiki/index.php/Support run by the author)

Unfortunately the main page does not have an English version, which make it difficult to see the extension in action (for English speakers).

MediaWiki Version

 * Version 2.5 was tested on MediaWiki version 1.22.9 (from git repository)
 * Version 2.3 was tested on MediaWiki version 1.22.0 (from git repository)
 * Version 2.2 was tested on MediaWiki version 1.22.0 (from git repository)
 * Version 2.0 was tested on MediaWiki version 1.19-alpha (from svn repository)
 * Version 1.2 was tested on MediaWiki version 1.15.5-1 (from Debian repository)
 * Version 1.1 was tested on MediaWiki version 1.16.0(b3). Works fine, except that it needed a minor change to line 358 of AccessControl.php (remove '&' from parameter to function controlEditAccess ). When viewing a page on a Linux server, the tags show. But on a Windows server, the tags don't show and it is fine! Still haven't figured that one out, but it is ok for my application.
 * Version 1.1 was tested on MediaWiki version 1.15
 * Version 1.0 of this extension has been tested and works fine on MediaWiki versions > 1.12.x.
 * Version 1.1 tested on MediaWiki version 1.16.1 with new patch from http://git.felk.cvut.cz/pub/git?p=accesscontrol.git;a=commitdiff;h=2f678deed0e4e4f77620e391c94559c7b50102a9