this.length = len;

        if ( isRetainPayload() ) {
            byte[] payload = new byte[len];
            System.arraycopy(buffer, 4, payload, 0, len);
            setRawPayload(payload);
        }

        if ( !verifySignature(buffer, 4, len) ) {
            throw new SMBProtocolDecodingException("Signature verification failed for " + this.getClass().getName());
        }
        return len;