So I decided to try hooking up a new install of openfire to my domain controller (Zentyal). Turns out you need a more recent version of prototype.js to make it work correctly.
cd /opt/openfire/plugins/admin/webapp/js; mv prototype.js prototype.js.old; wget https://ajax.googleapis.com/ajax/libs/prototype/1.7.1.0/prototype.js
systemctl restart openfire
At that point clear your browser cache if you had started the setup configuration via web browser already, and you should be able to complete the setup using your Active Directory information.
I know, I know, way beyond the article scope, but I figured it would save some of us a little headache.