Mod authnz ldap

mod_authnz_ldap and lookup

The Apache module mod_authnz_ldap allows an LDAP directory to be used to store the database for HTTP Basic authentication. In this wiki page we are going to explain how to use this module in conjunction with the lookup LDAP service and mod_ucam_webauth.

If you require more deep information than the one provided in this page, you can visit the lookup LDAP service webpage and/or the Apache mod_authnz_ldap webpage

Compatibility

All these examples have been tested with Apache 2.4. The same directives could be used for Apache 2.2 but these haven't been tested.

Enabling modules

To enable the apache modules to make authnz_ldap to work. Just type:

 a2enmod authnz_ldap
 a2enmod ldap

Security

Include the following directive to the mod_ldap configuration to make sure that all connections make by Apache to the LDAP server are secure. Modify the file /etc/apache2/mods-enabled/ldap.conf and add

 LDAPTrustedMode TLS

Basic documentation

Only allow access to members of any institution (InstID) in the Require list

 AuthType Ucam-WebAuth
 AuthLDAPUrl ldap://ldap.lookup.cam.ac.uk/ou=people,o=University%20of%20Cambridge,dc=cam,dc=ac,dc=uk
 Require ldap-attribute instID=UIS
 Require ldap-attribute instID=CL

Allow access only to the users with crsids listed in Require list

 AuthType Ucam-WebAuth
 AuthLDAPUrl ldap://ldap.lookup.cam.ac.uk/ou=people,o=University%20of%20Cambridge,dc=cam,dc=ac,dc=uk?uid
 Require ldap-user amc203
 Require ldap-user jw35
 Require ldap-user jml4

or

 AuthType Ucam-WebAuth
 AuthLDAPUrl ldap://ldap.lookup.cam.ac.uk/ou=people,o=University%20of%20Cambridge,dc=cam,dc=ac,dc=uk?uid
 Require ldap-user amc203 jw35 jml4

DO NOT use displayName as a ldap-attribute check. displayName is a user editable field.

Allow access only member of any of the groups listed in the Require list and in the ldap query

 AuthType Ucam-WebAuth
 AuthLDAPUrl ldap://ldap.lookup.cam.ac.uk/ou=groups,o=University%20of%20Cambridge,dc=cam,dc=ac,dc=uk???|(groupID=101611)(groupID=101855)
 Require ldap-attribute groupID=101855
 Require ldap-attribute groupID=101611

(where 101611=UIS staff and 101855=UIS test accounts).

Groups should be identified by numeric ID since names could be duplicated (maliciously or accidentally), causing failure or bogus matches and consequent authorisation.

More complex queries

More complex queries can be achieved using Require ldap-filter which accepts expressions.

Apache 2.4.8 or greater supports expressions in any ldap require directive.