My organization is currently using a third party service to manage online polls. They are interested in upgrading their website to include a forum, and i've recommended xenforo. They would like to continue using the third party service; however, they would like to allow users to have a single sign-on for both sites. We would need to provide a URL that they could use to authenticate the users sign-in details. The third party allows remote authentication and supports the following options: Flexmls, Shibboleth, SOAP, LDAP, XML/HTTPS, Facebook. Can xenforo be used in this manner?