docs. ensure non-random memory allocation headermac bytes.

libp2p/RLPxFrameIO.cpp

@@ -104,9 +104,8 @@ void RLPXFrameIO::writeSingleFramePacket(bytesConstRef _packet, bytes& o_bytes)
 	
 	// TODO: SECURITY check that header is <= 16 bytes
 
-	bytes headerWithMac;
-	header.swapOut(headerWithMac);
-	headerWithMac.resize(32);
+	bytes headerWithMac(h256::size);
+	bytesConstRef(&header.out()).copyTo(bytesRef(&headerWithMac));
 	m_frameEnc.ProcessData(headerWithMac.data(), headerWithMac.data(), 16);
 	updateEgressMACWithHeader(bytesConstRef(&headerWithMac).cropped(0, 16));
 	egressDigest().ref().copyTo(bytesRef(&headerWithMac).cropped(h128::size,h128::size));

libp2p/RLPxFrameIO.h

@@ -41,6 +41,12 @@ class RLPXHandshake;
 /**
  * @brief Encoder/decoder transport for RLPx connections established by RLPXHandshake.
  * Managed (via shared_ptr) socket for use by RLPXHandshake and RLPXFrameIO.
+ *
+ * Thread Safety
+ * Distinct Objects: Safe.
+ * Shared objects: Unsafe.
+ * * an instance method must not be called concurrently
+ * * a writeSingleFramePacket can be called concurrent to authAndDecryptHeader OR authAndDecryptFrame
  */
 class RLPXSocket: public std::enable_shared_from_this<RLPXSocket>
 {

libp2p/RLPxHandshake.cpp

@@ -133,6 +133,8 @@ void RLPXHandshake::error()
 {
 	clog(NetConnect) << "Disconnecting " << m_socket->remoteEndpoint() << " (Handshake Failed)";
 	m_socket->close();
+	if (m_io != nullptr)
+		delete m_io;
 }
 
 void RLPXHandshake::transition(boost::system::error_code _ech)
@@ -175,7 +177,7 @@ void RLPXHandshake::transition(boost::system::error_code _ech)
 		<< m_host->protocolVersion()
 		<< m_host->m_clientVersion
 		<< m_host->caps()
-		<< m_host->m_tcpPublic.port()
+		<< m_host->listenPort()
 		<< m_host->id();
 		bytes packet;
 		s.swapOut(packet);
@@ -252,7 +254,6 @@ void RLPXHandshake::transition(boost::system::error_code _ech)
 						}
 
 						clog(NetNote) << (m_originated ? "p2p.connect.egress" : "p2p.connect.ingress") << "hello frame: success. starting session.";
-						
 						RLP rlp(frame.cropped(1));
 						m_host->startPeerSession(m_remote, rlp, m_io, m_socket->remoteEndpoint());
 					}

libp2p/RLPxHandshake.h

@@ -36,66 +36,89 @@ namespace dev
 namespace p2p
 {
 
+/**
+ * @brief Setup inbound or outbound connection for communication over RLPXFrameIO.
+ * RLPx Spec: https://github.com/ethereum/devp2p/blob/master/rlpx.md#encrypted-handshake
+ *
+ * @todo Implement StartSession transition via lambda which is passed to constructor.
+ *
+ * Thread Safety
+ * Distinct Objects: Safe.
+ * Shared objects: Unsafe.
+ */
 class RLPXHandshake: public std::enable_shared_from_this<RLPXHandshake>
 {
 	friend class RLPXFrameIO;
+	
+	/// Sequential states of handshake
 	enum State
 	{
 		Error = -1,
-		New,				// New->AckAuth				[egress: tx auth, ingress: rx auth]
-		AckAuth,			// AckAuth->WriteHello		[egress: rx ack, ingress: tx ack]
-		WriteHello,		// WriteHello				[tx caps, rx caps, writehello]
+		New,
+		AckAuth,
+		WriteHello,
 		ReadHello,
 		StartSession
 	};
 	
 public:
-	/// Handshake for ingress connection. Takes ownership of socket.
+	/// Setup incoming connection.
 	RLPXHandshake(Host* _host, std::shared_ptr<RLPXSocket> const& _socket): m_host(_host), m_originated(false), m_socket(_socket) { crypto::Nonce::get().ref().copyTo(m_nonce.ref()); }
 	
-	/// Handshake for egress connection to _remote. Takes ownership of socket.
+	/// Setup outbound connection.
 	RLPXHandshake(Host* _host, std::shared_ptr<RLPXSocket> const& _socket, NodeId _remote): m_host(_host), m_remote(_remote), m_originated(true), m_socket(_socket) { crypto::Nonce::get().ref().copyTo(m_nonce.ref()); }
 
 	~RLPXHandshake() {}
 
+	/// Start handshake.
 	void start() { transition(); }
 
 protected:
+	/// Write Auth message to socket and transitions to AckAuth.
 	void writeAuth();
+	
+	/// Reads Auth message from socket and transitions to AckAuth.
 	void readAuth();
 	
+	/// Write Ack message to socket and transitions to WriteHello.
 	void writeAck();
+	
+	/// Reads Auth message from socket and transitions to WriteHello.
 	void readAck();
 	
+	/// Closes connection and ends transitions.
 	void error();
+	
+	/// Performs transition for m_nextState.
 	void transition(boost::system::error_code _ech = boost::system::error_code());
 
-	/// Current state of handshake.
-	State m_nextState = New;
+	State m_nextState = New;			///< Current or expected state of transition.
 	
-	Host* m_host;
+	Host* m_host;					///< Host which provides m_alias, protocolVersion(), m_clientVersion, caps(), and TCP listenPort().
 	
 	/// Node id of remote host for socket.
-	NodeId m_remote;
-	bool m_originated = false;
+	NodeId m_remote;					///< Public address of remote host.
+	bool m_originated = false;		///< True if connection is outbound.
 	
 	/// Buffers for encoded and decoded handshake phases
-	bytes m_auth;
-	bytes m_authCipher;
-	bytes m_ack;
-	bytes m_ackCipher;
-	bytes m_handshakeOutBuffer;
-	bytes m_handshakeInBuffer;
-	
-	crypto::ECDHE m_ecdhe;
-	h256 m_nonce;
-	
-	Public m_remoteEphemeral;
-	h256 m_remoteNonce;
-	
-	/// Frame IO is used to read frame for last step of handshake authentication.
-	RLPXFrameIO* m_io;
-	std::shared_ptr<RLPXSocket> m_socket;
+	bytes m_auth;					///< Plaintext of egress or ingress Auth message.
+	bytes m_authCipher;				///< Ciphertext of egress or ingress Auth message.
+	bytes m_ack;						///< Plaintext of egress or ingress Ack message.
+	bytes m_ackCipher;				///< Ciphertext of egress or ingress Ack message.
+	bytes m_handshakeOutBuffer;		///< Frame buffer for egress Hello packet.
+	bytes m_handshakeInBuffer;		///< Frame buffer for ingress Hello packet.
+	
+	crypto::ECDHE m_ecdhe;			///< Ephemeral ECDH secret and agreement.
+	h256 m_nonce;					///< Nonce generated by this host for handshake.
+	
+	Public m_remoteEphemeral;			///< Remote ephemeral public key.
+	h256 m_remoteNonce;				///< Nonce generated by remote host for handshake.
+	
+	/// Used to read and write RLPx encrypted frames for last step of handshake authentication.
+	/// Passed onto Host which will take ownership.
+	RLPXFrameIO* m_io = nullptr;
+	
+	std::shared_ptr<RLPXSocket> m_socket;	///< Socket.
 };
 	
 }