Table of Contents

LDAP Authentication Backend

Since the release 2013-05-10 “Weatherwax”
see AuthLDAP plugin page

For releases 2012-10-13 “Adora Belle” and older
see info below

This module allows authentication against an LDAP directory using the ACL feature. It is included with the DokuWiki releases. Don't forget to install your linux distribution module php-net-ldap (ex: apt-get install php-net-ldap). In distributions that are not Debian-based this module may have another name, like php5-ldap in openSUSE (zypper in php5-ldap).

Users can log into the wiki using their username and password defined in a LDAP server, adding new users is not supported through the LDAP backend.

:!: Do not report bugs or problems in the wiki! Use the bugtracker, mailinglist and forum instead.

Configuration

This is an example configuration to set in your conf/local.protected.php to authenticate against your LDAP directory.

$conf['useacl']      = 1;
$conf['openregister']= 0;
$conf['authtype']    = 'ldap';
 
#$conf['auth']['ldap']['server']      = 'localhost';
#$conf['auth']['ldap']['port']        = 389;
$conf['auth']['ldap']['server']      = 'ldap://server.tld:389'; #instead of the above two settings
$conf['auth']['ldap']['usertree']    = 'ou=People, dc=server, dc=tld';
$conf['auth']['ldap']['grouptree']   = 'ou=Group, dc=server, dc=tld';
$conf['auth']['ldap']['userfilter']  = '(&(uid=%{user})(objectClass=posixAccount))';
$conf['auth']['ldap']['groupfilter'] = '(&(objectClass=posixGroup)(|(gidNumber=%{gid})(memberUID=%{user})))';
 
# This is optional but may be required for your server:
#$conf['auth']['ldap']['version']    = 3;

# This enables the use of the STARTTLS command
#$conf['auth']['ldap']['starttls']   = 1;

# This is optional and is required to be off when using Active Directory:
#$conf['auth']['ldap']['referrals']  = 0;

# Optional bind user and password if anonymous bind is not allowed
#$conf['auth']['ldap']['binddn']     = 'cn=admin, dc=my, dc=home';
#$conf['auth']['ldap']['bindpw']     = 'secret';

# Mapping can be used to specify where the internal data is coming from. 
#$conf['auth']['ldap']['mapping']['name']  = 'displayname'; # Name of attribute Active Directory stores it's pretty print user name.
#$conf['auth']['ldap']['mapping']['grps']  = array('memberof' => '/CN=(.+?),/i'); # Where groups are defined in Active Directory

# Limit search scope for user and group searches (sub|one|base)
#$conf['auth']['ldap']['userscope']  = 'sub';
#$conf['auth']['ldap']['groupscope'] = 'sub';

# Optional debugging
#$conf['auth']['ldap']['debug']      = 1;

You can use the version parameter to tell PHP to use Version 3 of the LDAP protocol to connect to your server - default is version 2.

The userfilter defines an LDAP filter which is used to search for a user. The groupfilter is used to fetch the groups a user is in. Independent of the result all users are added to the default group.

The following variables are available for the userfilter and the groupfilter:

variable meaning
%{user} The username the user tried to login with
%{server} The server string provided in $conf['auth']['ldap']['server']

The groupfilter can also access all the attributes provided in the user object:

variable meaning
%{dn} The users dn eg. uid=user,ou=People,dc=server,dc=dk
%{uid} The uid of the user eg. user
%{…}

The mapping is used for directories that uses non “standard” names for attributes, a mapping can be applied a regexp to clean it up before replacing the target variable. For all variables but 'grps' only the first attribute is used to replace the variable if more than one is provided.

variable mapping meaning
grps array('memberof' => '/CN=(.+?),/i') Replace the content of grps with what is provided in the attribute memberof and apply this regexp /CN=(.+?),/i to every element in it.
name 'displayname' Replace the content of name with first element of 'displayname' attribute.

The search scope (depth) can be limited to sub, one and base using the optional userscope and groupscope parameters. They default to sub. Setting them to more limited searches can improve performance.

Authentication is done in these steps:

  1. First see if we need to do an anonymous bind by looking in the usertree for a %{user}:
    • If found: Set usertree as DN.
    • If not: Try to find a DN for the given login doing a search in the usertree with the given userfilter – there has to be exactly one result
  2. Try to bind with the found DN and the given password - if this succeeds access is granted
  3. For getting the groups a user is in, the groupfilter is used to search the grouptree.

Notes

Real World Examples

Below is a list of example configurations used by various users for various LDAP servers. These are examples! Be sure to adjust them to your specific server settings.