If you plan to use user creation feature, look function auth_user_create
and modify it for your needs.
You have to change all hardcoded attribute values to fit your LDAP-server.
+User-creation makes posible that your current
+users can authenticate with existings usernames/password and new users can
+create own accounts to LDAP-directory. I'm using this feature and new users
+are created to LDAP different context, without rights to other system. When
+user-creation feature is set like that, there's no known security issues.
I write ldap-module on Novell E-directory / Linux & Solaris ,
so all default values are for it.