- user authentication - checking a user's ID and password using an LDAP bind operation
- user registry export - exposing information about users and groups to the synchronization subsystem
Either of these functions can be used in isolation or in combination. When LDAP authentication is used without user registry export, default Alfresco person objects are created automatically for all those users who successfully log in. However, they will not be populated with attributes without user registry export enabled. LDAP user registry export is most likely to be used without LDAP authentication when chained with other authentication subsystems. For example, Kerberos against Active Directory, pass-through against ActiveDirectory, and possibly Samba on top of OpenLDAP.
The user registry export function assumes that groups are stored in LDAP as an object that has a repeating attribute, which defines the distinguished names of other groups, or users. This is supported in the standard LDAP schema using the groupOfNames type. See the example LDIF file in OpenLDAP tips.