I am deploying the new v13 VSA using the OVA method in my lab VMware environment today and discovered when deploying you could see an SSL warning for the OVA like this -

There is a fix for this but it requires that you install two CA certificates from Entrust to the vCenter Trusted Root Store which can be done from the WebUI. Once those are installed to your vCenter then deploying the OVA will not give you the SSL warning and show a valid certificate.
CA Certificates to install -

After that when deploying OVA no more warning and valid certificate -

Hopefully this helps those that are keen on testing things in your lab environments.