title: Determine if a string contains a base64 string inside of it
body: <p>I'm trying to figure out a way to parse out a base64 string from with a larger string.</p>
  
  <p>I have the string <code>"Hello &lt;base64 content&gt; World"</code> and I want to be able to parse out the base64 content and convert it back to a string. <code>"Hello Awesome World"</code></p>
  
  <p>Answers in C# preferred.</p>
  
  <p><b>Edit:</b> Updated with a more real example.</p>
  
  <pre><code>--abcdef
  \n
  Content-Type: Text/Plain;
  Content-Transfer-Encoding: base64
  \n
  &lt;base64 content&gt;
  \n
  --abcdef--
  </code></pre>
  
  <p>This is taken from 1 sample.  The problem is that the Content.... vary quite a bit from one record to the next.</p>