title: iOS Passbook: how to use ruby to generate signature for pass
body: <p>I used to do this in shell:</p>
  
  <pre><code>openssl smime -binary -sign -certfile WWDR.pem -signer passcertificate.pem -inkey passkey.pem -in manifest.json -out signature -outform DER -passin pass:12345
  </code></pre>