How do you configure a Heroku Rack/Rails app to authenticate the client certificate of an incoming request?

Question

Say I have a Web service, called JokeService , which is a Rack/Rails3 app deployed on Heroku. And lets say I have an application, called ComedyApp . Now, I want JokeService to only entertain requests from ComedyApp . To do so, I would like ComedyApp to use a client certificate, which it uses to authenticate itself with JokeService .

My question is, how the heck can I configure the JokeService (again, a Rack/Rails3 app on Heroku) to check the validity of the client certificate?

This is related, but unanswered: How to access SSL client certificate from rack app

Answer 1

In short, you can't, since we don't have control of the http layer (thin or the routing mesh) in the stack.

An alternative is to authenticate one's requests simply using a custom request header.