The CAS Login URL and Validation URL required when configuring client libraries in your applications are:

CAS Login URL
https://cas.ust.hk/cas/login

CAS Validation URL
https://cas.ust.hk/cas/serviceValidate

NB: The non-standard 8443

SSL port was used in early CAS server deployment. For compatibility reasons, SSL port 8443 is still supported for the above URLs. However, we strongly recommend that early deployers now change to the standard SSL port as problem reports note that some internet providers block the non-standard port.