import com.subgraph.orchid.circuits.CircuitNodeCryptoState; //导入依赖的package包/类
HiddenServiceCircuit processRendezvous2(TorTapKeyAgreement kex) {
	final RelayCell cell = circuit.receiveRelayCell();
	if(cell == null) {
		logger.info("Timeout waiting for RENDEZVOUS2");
		return null;
	} else if (cell.getRelayCommand() != RelayCell.RELAY_COMMAND_RENDEZVOUS2) {
		logger.info("Unexpected Relay cell type received while waiting for RENDEZVOUS2: "+ cell.getRelayCommand());
		return null;
	}
	final BigInteger peerPublic = readPeerPublic(cell);
	final HexDigest handshakeDigest = readHandshakeDigest(cell);
	if(peerPublic == null || handshakeDigest == null) {
		return null;
	}
	final byte[] verifyHash = new byte[TorMessageDigest.TOR_DIGEST_SIZE];
	final byte[] keyMaterial = new byte[CircuitNodeCryptoState.KEY_MATERIAL_SIZE];
	if(!kex.deriveKeysFromDHPublicAndHash(peerPublic, handshakeDigest.getRawBytes(), keyMaterial, verifyHash)) {
		logger.info("Error deriving session keys while extending to hidden service");
		return null;
	}
	return circuit.connectHiddenService(CircuitNodeImpl.createAnonymous(circuit.getFinalCircuitNode(), keyMaterial, verifyHash));
}