title: How to perform an NTLM challenge on the iPhone
body: <p>I'm trying to access some web services in an iPhone application.</p>
  
  <p>If I <code>GET</code> to the .asmx page, I authenticate and get the WSDL as expected.</p>
  
  <p>However, if I <code>POST</code> to the .asmx page, setting the SOAPAction, Content-Type, Content-Length, and HTTPBody, I just keep getting <code>didReceiveAuthenticationChallenge</code> messages.</p>
  
  <p>Additionally, I'm trying to POST to IIS using Integrated Windows Authentication (IWA), which means I'm trying to negotiate an NTLM challenge.</p>