return false;
        }

        PreauthIntegrityNegotiateContext rpc = null;
        for ( NegotiateContextRequest rnc : req.getNegotiateContexts() ) {
            if ( rnc instanceof PreauthIntegrityNegotiateContext ) {
                rpc = (PreauthIntegrityNegotiateContext) rnc;
            }
        }
        if ( rpc == null ) {
            return false;
        }

        boolean valid = false;