Verify connected nodes identity.

src/Peer.cpp

@@ -97,7 +97,6 @@ void Peer::connect(const std::string strIp, int iPort)
 {
 	int	iPortAct	= iPort < 0 ? SYSTEM_PEER_PORT : iPort;
 
-	// XXX Should not print IP if not known sane.
 	std::cerr  << "Peer::connect: " << strIp << " " << iPort << std::endl;
 	mIpPort		= make_pair(strIp, iPort);
 
@@ -142,7 +141,7 @@ void Peer::connect(const std::string strIp, int iPort)
 // We have an ecrypted connection to the peer.
 // Have it say who it is so we know to avoid redundant connections.
 // Establish that it really who we are talking to by having it sign a connection detail.
-// XXX Also need to establish no man in the middle attack is in progress.
+// Also need to establish no man in the middle attack is in progress.
 void Peer::handleStart(const boost::system::error_code& error)
 {
 	if (error)
@@ -173,9 +172,7 @@ void Peer::handleConnect(const boost::system::error_code& error, boost::asio::ip
 	    mSocketSsl.set_verify_mode(boost::asio::ssl::verify_none);
 
 	    mSocketSsl.async_handshake(boost::asio::ssl::stream<boost::asio::ip::tcp::socket>::client,
-			boost::bind(&Peer::handleStart,
-				shared_from_this(),
-				boost::asio::placeholders::error));
+			boost::bind(&Peer::handleStart, shared_from_this(), boost::asio::placeholders::error));
 	}
 }
 
@@ -215,9 +212,7 @@ void Peer::connected(const boost::system::error_code& error)
 	    mSocketSsl.set_verify_mode(boost::asio::ssl::verify_none);
 
 	    mSocketSsl.async_handshake(boost::asio::ssl::stream<boost::asio::ip::tcp::socket>::server,
-			boost::bind(&Peer::handleStart,
-				shared_from_this(),
-				boost::asio::placeholders::error));
+			boost::bind(&Peer::handleStart, shared_from_this(), boost::asio::placeholders::error));
 	}
 }
 
@@ -488,14 +483,15 @@ void Peer::recvHello(newcoin::TMHello& packet)
 #endif
 	bool	bDetach	= true;
 
-	if (mNodePublic.isValid())
-	{
-		std::cerr << "Recv(Hello): Disconnect: Extraneous node public key." << std::endl;
-	}
-	else if (!mNodePublic.setNodePublic(packet.nodepublic()))
+	if (!mNodePublic.setNodePublic(packet.nodepublic()))
 	{
 		std::cerr << "Recv(Hello): Disconnect: Bad node public key." << std::endl;
 	}
+	else if (!mNodePublic.verifyNodePublic(mCookieHash, packet.nodeproof()))
+	{
+		// Unable to verify they have private key for claimed public key.
+		std::cerr << "Recv(Hello): Disconnect: Failed to verify session." << std::endl;
+	}
 	else if (!theApp->getConnectionPool().peerConnected(shared_from_this(), mNodePublic))
 	{
 		// Already connected, self, or some other reason.
@@ -504,12 +500,13 @@ void Peer::recvHello(newcoin::TMHello& packet)
 	else
 	{
 		// Successful connection.
+
+		// Cancel verification timeout.
+		(void) mVerifyTimer.cancel();
+
 		// XXX Set timer: connection is in grace period to be useful.
 		// XXX Set timer: connection idle (idle may vary depending on connection type.)
 
-		// XXX Only kill if verified no man-in-the-middle.
-		(void) mVerifyTimer.cancel();
-
 		bDetach	= false;
 	}
 
@@ -712,36 +709,50 @@ void Peer::recvLedger(newcoin::TMLedgerData& packet)
 		punishPeer(PP_UNWANTED_DATA);
 }
 
-std::vector<unsigned char> Peer::getSessionCookie()
+// Get session information we can sign to prevent man in the middle attack.
+// (both sides get the same information, neither side controls it)
+void Peer::getSessionCookie(std::string& strDst)
 {
-	// get session information we can sign
-	// (both sides get the same information, neither side controls it)
 	SSL* ssl = mSocketSsl.native_handle();
 	if (!ssl) throw std::runtime_error("No underlying connection");
 
 	// Get both finished messages
 	unsigned char s1[1024], s2[1024];
-	int l1 = SSL_get_finished(ssl, s1, 1024);
-	int l2 = SSL_get_finished(ssl, s2, 1024);
-	if ((l1 < 16) || (l2 < 16)) throw std::runtime_error("Connection setup not complete");
+	int l1 = SSL_get_finished(ssl, s1, sizeof(s1));
+	int l2 = SSL_get_peer_finished(ssl, s2, sizeof(s2));
+
+	if ((l1 < 12) || (l2 < 12))
+		throw std::runtime_error(str(boost::format("Connection setup not complete: %d %d") % l1 % l2));
 
 	// Hash them and XOR the results
-	unsigned char sha1[32], sha2[32];
+	unsigned char sha1[64], sha2[64];
+
 	SHA512(s1, l1, sha1);
 	SHA512(s2, l2, sha2);
-	for(int i=0; i<32; i++) sha1[i]^=sha2[i];
-	return std::vector<unsigned char>(sha1, sha1+33);
+
+	for (int i=0; i<sizeof(sha1); i++)
+		sha1[i] ^= sha2[i];
+
+	strDst.assign((char *) &sha1[0], sizeof(sha1));
 }
 
 void Peer::sendHello()
 {
-	// XXX Start timer for hello required by.
+	std::string					strCookie;
+	std::vector<unsigned char>	vchSig;
+
+	getSessionCookie(strCookie);
+	mCookieHash	= Serializer::getSHA512Half(strCookie);
+
+	theApp->getWallet().getNodePrivate().signNodePrivate(mCookieHash, vchSig);
+
 	newcoin::TMHello* h=new newcoin::TMHello();
-	// set up parameters
+
 	h->set_version(theConfig.VERSION);
 	h->set_ledgerindex(theApp->getOPs().getCurrentLedgerID());
 	h->set_nettime(theApp->getOPs().getNetworkTime());
 	h->set_nodepublic(theApp->getWallet().getNodePublic().humanNodePublic());
+	h->set_nodeproof(&vchSig[0], vchSig.size());
 	h->set_ipv4port(theConfig.PEER_PORT);
 
 	Ledger::pointer closingLedger=theApp->getMasterLedger().getClosingLedger();

src/Peer.h

@@ -33,6 +33,7 @@ public:
 private:
 	NewcoinAddress	mNodePublic;		// Node public key of peer.
 	ipPort			mIpPort;
+	uint256			mCookieHash;
 
     boost::asio::ssl::stream<boost::asio::ip::tcp::socket>		mSocketSsl;
 
@@ -81,7 +82,7 @@ protected:
 	void recvGetLedger(newcoin::TMGetLedger& packet);
 	void recvLedger(newcoin::TMLedgerData& packet);
 
-	std::vector<unsigned char> getSessionCookie();
+	void getSessionCookie(std::string& strDst);
 
 public:
 	typedef boost::shared_ptr<Peer> pointer;

src/newcoin.proto

@@ -38,9 +38,10 @@ message TMHello {
 	required uint32 version				= 1;
 	optional uint32 ledgerIndex			= 2;
 	optional uint64 netTime				= 3;
-	optional bytes nodePublic			= 4; // node may opt to remain anonymous
-	optional uint32 ipv4Port			= 5;
-	optional bytes closedLedger 		= 6;
+	optional bytes	nodePublic			= 4; // node may opt to remain anonymous
+	optional bytes	nodeProof			= 5;
+	optional uint32 ipv4Port			= 6;
+	optional bytes	closedLedger 		= 7;
 }