title: libcurl c/c++ Kerberos authentication
body: <p>Does anybody have any experience with libcurl (C/C++) and Kerberos authentication?</p>
  
  <p>I am able to set everything up and post data - however, now we have switched on SSO (via SPNEGO on a JBoss server) I am unable to authenticate properly, with authorization being downgraded to Basic.</p>
  
  <p>At this stage I am using curl_easy_setopt(curl,CURLOPT_HTTPAUTH, CURLAUTH_GSSNEGOTIATE) and have also set the CURLOPT_KRBLEVEL to "private".</p>
  
  <p>Looking at the headers in wireshark, the response from curl doesn't provide any credentials - which is throwing an EncryptionKey exception on the JBoss server. I am able to authenticate on the server via .NET using cached credentials and a httprequest object. Only problem is we can't use .NET on this project.</p>
  
  <p>Thanks in advance for any help.</p>
  
  <ul>
  <li>As an additional point. I have just seen that under libcurl Kerberos is only supported for ftp. I am trawling the source to try and confirm if this is the case. Anybody know of any other libraries that we might be able to use to perform our POST?</li>
  </ul>