modifier.setClientName( getPrincipalName( "tquist" ) );
modifier.setServerName( getPrincipalName( "hnelson" ) );
modifier.setRealm( "EXAMPLE.COM" );
modifier.setEType( config.getEncryptionTypes() );
KdcRequest message = new KdcRequest( 5, KerberosMessageType.AS_REQ, null, modifier.getRequestBody() );
handler.messageReceived( session, message );
ErrorMessage error = ( ErrorMessage ) session.getMessage();
assertEquals( "The client or server has a null key", 9, error.getErrorCode() );