Please read for an updated status on RailsCasts:
Learn more or hide this
GitHub User: nwwatson
Are you using nginx with Trinidad? If so, you would set up the SSL on nginx and ensure that external traffic is not accepted on the port that nginx is forwarding traffic to Trinidad. On ubuntu, you would do this through ufw or iptables.
Traffic between nginx and trinidad would be loopback, so you shouldn't need an SSL unless you are forwarding to a separate server.
Did you ever get an answer to your question? I'm having the same problem.