title: How to determine if ViewState has MAC enabled when crawling a page?
body: <p>I was using <a href="http://portswigger.net/burp/" rel="nofollow">Burp Suite</a> to do some security testing on a site and I noticed that when it detects ViewState it will automatically tell you whether it has MAC enabled.  </p>
  
  <p>I'm curious if anyone know of a programatic way to determine if MAC is enabled if you are crawling a site without actually attempting to modify the ViewState, submit it and see if anything blows up?</p>
  
  <p>From what I can tell Burp Suite is doing this just by look at the request (and not modifying/submitting).</p>