import com.subgraph.orchid.ConnectionHandshakeException; //导入依赖的package包/类
void recvCerts() throws ConnectionHandshakeException  {
	final Cell cell = expectCell(Cell.CERTS);
	final int ncerts = cell.getByte();
	if(ncerts != 2) {
		throw new ConnectionHandshakeException("Expecting 2 certificates and got "+ ncerts);
	}

	linkCertificate = null;
	identityCertificate = null;
	
	for(int i = 0; i < ncerts; i++) {
		int type = cell.getByte();
		if(type == 1) {
			linkCertificate = testAndReadCertificate(cell, linkCertificate, "Link (type = 1)");
		} else if(type == 2) {
			identityCertificate = testAndReadCertificate(cell, identityCertificate, "Identity (type = 2)");
		} else {
			throw new ConnectionHandshakeException("Unexpected certificate type = "+ type + " in CERTS cell");
		}
	}
	
}
 

import com.subgraph.orchid.ConnectionHandshakeException; //导入依赖的package包/类
void verifyCertificates() throws ConnectionHandshakeException {
	PublicKey publicKey = identityCertificate.getPublicKey();
	verifyIdentityKey(publicKey);
	RSAPublicKey rsaPublicKey = (RSAPublicKey) publicKey;
	
	if(rsaPublicKey.getModulus().bitLength() != 1024) {
		throw new ConnectionHandshakeException("Invalid RSA modulus length in router identity key");
	}
	
	try {
		identityCertificate.checkValidity();
		identityCertificate.verify(rsaPublicKey);
		linkCertificate.checkValidity();
		linkCertificate.verify(rsaPublicKey);
	} catch (GeneralSecurityException e) {
		throw new ConnectionHandshakeException("Router presented invalid certificate chain in CERTS cell");
	}

	RSAPublicKey rsa2 = (RSAPublicKey) linkCertificate.getPublicKey();
	if(!getConnectionPublicKey().getModulus().equals(rsa2.getModulus())) {
		throw new ConnectionHandshakeException("Link certificate in CERTS cell does not match connection certificate");
	}
}
 

import com.subgraph.orchid.ConnectionHandshakeException; //导入依赖的package包/类
private X509Certificate testAndReadCertificate(Cell cell, X509Certificate currentValue, String type) throws ConnectionHandshakeException {
	if(currentValue == null) {
		return readCertificateFromCell(cell);
	} else {
		throw new ConnectionHandshakeException("Duplicate "+ type + " certificates in CERTS cell");
	}
}
 

import com.subgraph.orchid.ConnectionHandshakeException; //导入依赖的package包/类
void recvAuthChallengeAndNetinfo() throws ConnectionHandshakeException {
	final Cell cell = expectCell(Cell.AUTH_CHALLENGE, Cell.NETINFO);
	if(cell.getCommand() == Cell.NETINFO) {
		processNetInfo(cell);
		return;
	}
	final Cell netinfo = expectCell(Cell.NETINFO);
	processNetInfo(netinfo);
}
 

import com.subgraph.orchid.ConnectionHandshakeException; //导入依赖的package包/类
static ConnectionHandshake createHandshake(TorConfig config, ConnectionImpl connection, SSLSocket socket) throws ConnectionHandshakeException {
	if(config.getHandshakeV3Enabled() && ConnectionHandshakeV3.sessionSupportsHandshake(socket.getSession())) {
		return new ConnectionHandshakeV3(connection, socket);
	} else if(config.getHandshakeV2Enabled()) {
		return new ConnectionHandshakeV2(connection, socket);
	} else {
		throw new ConnectionHandshakeException("No valid handshake type available for this connection");
	}
		
}
 

import com.subgraph.orchid.ConnectionHandshakeException; //导入依赖的package包/类
protected Cell expectCell(Integer... expectedTypes) throws ConnectionHandshakeException {
	try {
		final Cell c = connection.readConnectionControlCell();
		for(int t: expectedTypes) {
			if(c.getCommand() == t) {
				return c;
			}
		}
		final List<Integer> expected = Arrays.asList(expectedTypes);
		throw new ConnectionHandshakeException("Expecting Cell command "+ expected + " and got [ "+ c.getCommand() +" ] instead");
	} catch (ConnectionIOException e) {
		throw new ConnectionHandshakeException("Connection exception while performing handshake "+ e);
	}
}
 

import com.subgraph.orchid.ConnectionHandshakeException; //导入依赖的package包/类
protected void verifyIdentityKey(PublicKey publicKey) throws ConnectionHandshakeException {
	if(!(publicKey instanceof RSAPublicKey)) {
		throw new ConnectionHandshakeException("Identity certificate public key is not an RSA key as expected");
	}
	final TorPublicKey identityKey = new TorPublicKey((RSAPublicKey)publicKey);
	final Router router = connection.getRouter();
	if((router instanceof BridgeRouter) && (router.getIdentityHash() == null)) {
		logger.info("Setting Bridge fingerprint from connection handshake for "+ router);
		((BridgeRouter) router).setIdentity(identityKey.getFingerprint());
	} else if(!identityKey.getFingerprint().equals(router.getIdentityHash())) {
		throw new ConnectionHandshakeException("Router identity does not match certificate key");
	}
}