HTTP Authentication Plugin

Last successfully tested: 2023-09-20 with PHP 8.0.30 and DokuWiki 2023-04-04a “Jack Jackrum”

This auth plugin is for you if you don't want your users to have to login through the login form all the time when you have instead already configured your webserver to perform some sort of authentication (eg. HTTP Basic or NTLM authentication). In that case, the Webserver provides a user's credentials to PHP scripts through the superglobal variables $_SERVER['PHP_AUTH_USER'] and $_SERVER['PHP_AUTH_PW'].

Out of the box DokuWiki will already pick these up and pretend the user supplied those through the login form. It will perform authentication using the configured auth plugin (usually authplain) and, if successful, show the user (and the admin) options depending on the auth plugin's capabilities.

This all works out as long as

• either DokuWiki's auth plugin does not report capabilities such as change login name, change password, add user, edit user, delete user so that DokuWiki consequently does not expose these controls to the user
• or the Webserver and DokuWiki's auth plugin use the same source for their authentication.

If the first condition is not true, ie. the plugin does provide the named capabilities, the user could attempt to change his password through the “User profile” function. The admin, through the “User manager”, could also change his login name, delete him or add him with a different login name.

Now if the second condition is also not true, there can be inconsistencies between the HTTP authentication (which might eg. use an old password) and DokuWiki's auth plugin (which might have stored a new password somewhere else), causing Single Sign-On to break and errors to be displayed.

Note that this is not a bug in DokuWiki - DokuWiki can't in any way know how your Webserver's HTTP authentication has been set up.

For example, if you configure your Webserver to display the username/password prompt but not to actually validate them, there is no problem at all since DokuWiki (without this plugin) is the only entity doing actual authentication. This might actually be a considerable setup since there is not much point in authenticating twice. httpauth-passthru describes this.

This plugin does it the other way round. It assumes that the web server already did the authentication and essentially annuls DokuWiki's own authentication by providing a minimalistic checkPass() method which does not really authenticate. It merely checks that DokuWiki's idea of username/password equals the HTTP authentication credentials which should always be the case (except if you did not enable HTTP authentication in your Webserver).

Note however that DokuWiki expects information that HTTP authentication does not provide and where the plugin thus has to improvise:

• the user's real name: authhttp will simply return the user's login name here.
• the user's email address: authhttp makes one up by appending a configurable domain part to the user's login name. This will generate email addresses that will probably not work. There is not really a way around this, so you might want to disable email-related functions in DokuWiki.
• the user's groups: authhttp will simply put all users in DokuWiki's “defaultgroup”. Users whose login names are listed in “specialusers” will also be reported to be member of “specialgroup”. If you did not modify DokuWiki's “superuser” configuration setting default of “@admin”, you should leave this setting at “admin” as well and put users supposed to be admins in “specialusers”.

If these limitations are not acceptable, you might want to combine authhttp with another plugin, authsplit. authhttp comes with an action plugin that improves integration with authsplit:

• When authhttp is the primary auth plugin for authsplit, there could be the case that while users are known to authhttp, they aren't to the secondary auth plugin yet, so they'd have to register (unless authsplit's autocreate_users feature is used). In this scenario, the username for registration should match the HTTP authentication username. Also, the login form should be hidden because there is not much sense in offering a form-based login when HTTP authentication is used. authhttp's action plugin takes care of all that.
• When authhttp is used on its own, ie. without authsplit, users are always logged in and “registered”, so authhttp's action plugin won't have a visible effect.

Search and install the plugin using the Extension Manager. Alternatively, download the latest version from GitHub to the lib/plugins and rename the extracted directory to authhttp, otherwise the plugin won't work. Please refer to Plugins for additional info on how to install plugins in DokuWiki.

• usernameregex: a regular expression specifying the username part of the HTTP authentication login name (the string in $_SERVER['PHP_AUTH_USER']). Examples:
  • .+ for UNIX/passwd environments (ie. user name = login name)
  • ^[^@]+ for Kerberos environments with user@domain login names, uses everything before the @ character as user name
  • \\[^\\]+$ for Windows domain environments with DOMAIN\USER login names, uses everything after the \ character as user name
• emaildomain: the domain to append to login names to generate email addresses.
• specialusers: the login names of users to be put in the special group. You can list multiple login names separated by space.
• specialgroup: the name of the special group.

Note: when authhttp is used together with authsplit and authhttp is the primary auth plugin for authsplit, the last three configuration settings above will have no effect any longer due to the way authsplit works.

• Auth plugin constructors should set success == true when finished (2023-09-20 16:52)
• Ensure that PHP_AUTH_USER is actually present in $_SERVER before chec… (2023-09-20 16:48)
• Coding style (2023-09-20 16:44)
• Revert "Coding style" (2023-09-20 16:44)
• Remove dead ggauth link from README (2023-09-20 15:14)
• Bump version, copyright year and last tested versions, reword ggauth … (2023-09-20 15:07)
• Coding style (2023-09-20 14:59)
• Move "active" detection/var inside class constructors/instances (2023-09-20 14:56)

This plugin is based on ideas in the “ggauth” auth backend by Grant Gardner. Grant has not been maintaining ggauth for DokuWiki versions after “WeatherWax”. Also, his “http” auth backend uses trustExternal() which eg. does not support group memberships if used on its own, ie. without the ggauth “split” auth backend.

Please use the Discussion page for user comments.