This is a tool I developed after dealing with a lot of SSL certificates in Heroku Support.
Just gem install certutil to install it.
rbenv rehash if you're using rbenv. You might have to do something to RVM to get it to show up there; honestly I can't remember.
This app uses locally saved certificate files (ones that look like ---BEGIN CERTIFICATE---), or it can fetch them from a live site directly.
Just run certutil file.crt for a local file, or certutil google.com to get the cert from the web.
By default, the app parses the cert chain and displays a decoded version of the entire chain. See certutil --help for more options, or rake features to see some example use cases.