title: Rijndael encryption in Ruby
body: <p>I am totally new to encryption, so this question might be trivial - however, I had to google for 2 hours to understand even the basic terms, so bear with me.</p>
  
  <p>The string I need to send is a Base64 Encoded String of an encrypted JSON object. Here's the spec they sent me:</p>
  
  <ul>
  <li>Encryption Method: Rijndael </li>
  <li>Cipher Mode: CBC </li>
  <li>Padding Mode: PKCS7</li>
  <li>We will provide you with a custom Base64Encoded Key and IV.</li>
  </ul>
  
  <p>I checked out crypt's Rijndael algorithm, but I don't see where to plug the IV into... Not sure if CBC and PKCS7 are default - if they aren't, I don't know how to change these either...</p>
  
  <p>So:</p>
  
  <ul>
  <li>Can be crypt easily modified to support this stuff?</li>
  <li>Maybe it does support it already as-it-is, just my total lack of cryptographic knowledge doesn't allow for a proper use?</li>
  <li>If neither of the above, is it possible to do this in Ruby?</li>
  </ul>