title: GSSException: [..] Encryption type AES256CTS mode with HMAC SHA1-96 is not supported/enabled
body: <p>After setting our domain users to support AES encryption for Kerberos tokens (Windows Server 2008R2), on a web-application server side we get the following exception:</p>
  
  <blockquote>
    <p>GSSException: Failure unspecified at GSS-API level (Mechanism level:
    Encryption type AES256CTS mode with HMAC SHA1-96 is not
    supported/enabled)</p>
  </blockquote>
  
  <p>Strangely we have Java 6 (1.6.0_27) , which means that AES should be supported, according to this document: <a href="http://docs.oracle.com/javase/6/docs/technotes/guides/security/jgss/jgss-features.html" rel="nofollow">http://docs.oracle.com/javase/6/docs/technotes/guides/security/jgss/jgss-features.html</a></p>
  
  <p>Any ideas what's missing in our web-application or Java, or third parties? We are using Spring security Kerberos extension (with minimal code modifications to fit into our current Spring 2.x version and additional authentication requirements).</p>