I need to authenticate my users against a big organization-wide LDAP that I cannot control in any way. Only a smal part of LDAP users shall have access to my wiki, so I will have to define that locally.
To achieve that I have introduced a new configuration variable ($conf['auth']['ldap']['localgroup']) and patched ldap.class.php with a small snippet from basic auth.
My installation uses this patch since May 2007.
Patch (against Dokuwiki rc2008-03-31) attached.