title: Using OPENSSL_RAW_DATA param in openssl_decrypt with php 5.3
body: <p>My company is implementing V.me checkout on our site. Visa has provided us with a file of php helper functions for decrypting data, but one of them uses <code>openssl_decrypt</code> with the <code>OPENSSL_RAW_DATA</code> parameter, which only became available in PHP 5.4.something.</p>
  
  <pre><code>return openssl_decrypt($data, 'aes-256-cbc', hashKey($key), OPENSSL_RAW_DATA, $iv);
  </code></pre>
  
  <p>We are running PHP 5.3, and there is no option to upgrade. How can I modify this function so it still does what it was designed to do, without that global parameter being available?</p>