At Villanova, we don’t try to populate cat_username from LDAP; we use LDAP for authentication, but if the user tries to access Voyager functionality, they get prompted to enter barcode and last name separately. If this is the behavior you desire, you should be able to achieve it simply by commenting out the cat_username / cat_password LDAP settings in your configuration.
And actually, since you are talking about names, is it actually the cat_password field that is causing you trouble? Shouldn’t cat_username be a barcode?
Assuming that you have a barcode from LDAP, you might be able to add some custom code to do an Oracle lookup of the user’s last name in the Voyager database based on the barcode, and then use that data to populate cat_username/cat_password. That might get a little messy, but I can make some suggestions if you need help.