complete Bob side of NTCP2

libi2pd/NTCP2.cpp

@@ -41,7 +41,7 @@ namespace transport
 		HMAC(EVP_sha256(), tempKey, 32, m_CK, 33, derived, &len); 	
 	}
 
-	void NTCP2Establisher::KeyDerivationFunction1 (const uint8_t * rs, const uint8_t * priv, const uint8_t * pub)
+	void NTCP2Establisher::KeyDerivationFunction1 (const uint8_t * pub, const uint8_t * priv, const uint8_t * rs, const uint8_t * epub)
 	{
 		static const uint8_t protocolNameHash[] = 
 		{ 
@@ -60,28 +60,28 @@ namespace transport
 		SHA256_Update (&ctx, hh, 32);			
 		SHA256_Update (&ctx, rs, 32);			
 		SHA256_Final (m_H, &ctx);
-		// h = SHA256(h || pub)
+		// h = SHA256(h || epub)
 		SHA256_Init (&ctx);
 		SHA256_Update (&ctx, m_H, 32);
-		SHA256_Update (&ctx, pub, 32);
+		SHA256_Update (&ctx, epub, 32);
 		SHA256_Final (m_H, &ctx);
 		// x25519 between rs and priv
 		uint8_t inputKeyMaterial[32];
-		i2p::crypto::GetEd25519 ()->ScalarMul (rs, priv, inputKeyMaterial, m_Ctx); // rs*priv
+		i2p::crypto::GetEd25519 ()->ScalarMul (pub, priv, inputKeyMaterial, m_Ctx); // rs*priv
 		MixKey (inputKeyMaterial, m_K);
 	}
 
 	void NTCP2Establisher::KDF1Alice ()
 	{
-		KeyDerivationFunction1 (m_RemoteStaticKey, GetPriv (), GetPub ());
+		KeyDerivationFunction1 (m_RemoteStaticKey, GetPriv (), m_RemoteStaticKey, GetPub ());
 	}
 	
 	void NTCP2Establisher::KDF1Bob ()
 	{
-		KeyDerivationFunction1 (GetRemotePub (), i2p::context.GetNTCP2StaticPrivateKey (), GetRemotePub ()); 
+		KeyDerivationFunction1 (GetRemotePub (), i2p::context.GetNTCP2StaticPrivateKey (), i2p::context.GetNTCP2StaticPublicKey (), GetRemotePub ()); 
 	}
 
-	void NTCP2Establisher::KeyDerivationFunction2 (const uint8_t * sessionRequest, size_t sessionRequestLen)
+	void NTCP2Establisher::KeyDerivationFunction2 (const uint8_t * sessionRequest, size_t sessionRequestLen, const uint8_t * epub)
 	{		
 		SHA256_CTX ctx;
 		SHA256_Init (&ctx);
@@ -99,7 +99,7 @@ namespace transport
 		}	
 		SHA256_Init (&ctx);
 		SHA256_Update (&ctx, m_H, 32);
-		SHA256_Update (&ctx, GetRemotePub (), 32); 
+		SHA256_Update (&ctx, epub, 32); 
 		SHA256_Final (m_H, &ctx);
 
 		// x25519 between remote pub and priv
@@ -108,6 +108,16 @@ namespace transport
 		MixKey (inputKeyMaterial, m_K);
 	}
 
+	void NTCP2Establisher::KDF2Alice (const uint8_t * sessionRequest, size_t sessionRequestLen)
+	{
+		KeyDerivationFunction2 (sessionRequest, sessionRequestLen, GetRemotePub ());
+	}
+	
+	void NTCP2Establisher::KDF2Bob (const uint8_t * sessionRequest, size_t sessionRequestLen)
+	{
+		 KeyDerivationFunction2 (sessionRequest, sessionRequestLen, GetPub ());
+	}
+
 	void NTCP2Establisher::KDF3Alice ()
 	{
 		uint8_t inputKeyMaterial[32];
@@ -137,7 +147,9 @@ namespace transport
 		m_ReceiveSequenceNumber (0), m_SendSequenceNumber (0), m_IsSending (false)
 	{
 		m_Establisher.reset (new NTCP2Establisher);
-		auto addr = in_RemoteRouter->GetNTCPAddress ();
+		if (in_RemoteRouter) // Alice
+		{
+			auto addr = in_RemoteRouter->GetNTCP2Address ();
 			if (addr->ntcp2)
 			{
 				memcpy (m_Establisher->m_RemoteStaticKey, addr->ntcp2->staticKey, 32);
@@ -146,6 +158,7 @@ namespace transport
 			else
 				LogPrint (eLogWarning, "NTCP2: Missing NTCP2 parameters"); 
 		}
+	}
 
 	NTCP2Session::~NTCP2Session ()
 	{
@@ -331,7 +344,7 @@ namespace transport
 		encryption.SetIV (m_Establisher->m_IV);
 		encryption.Encrypt (m_Establisher->GetPub (), 32, m_SessionCreatedBuffer); // Y
 		// encryption key for next block (m_K)
-		m_Establisher->KeyDerivationFunction2 (m_SessionRequestBuffer, m_SessionRequestBufferLen);	
+		m_Establisher->KDF2Bob (m_SessionRequestBuffer, m_SessionRequestBufferLen);	
 		auto paddingLen = rand () % (287 - 64);
 		uint8_t options[16];
 		memset (options, 0, 16);
@@ -342,7 +355,7 @@ namespace transport
 		memset (nonce, 0, 12); // set nonce to zero
 		i2p::crypto::AEADChaCha20Poly1305 (options, 16, m_Establisher->GetH (), 32, m_Establisher->GetK (), nonce, m_SessionCreatedBuffer + 32, 32, true); // encrypt
 		// fill padding
-		RAND_bytes (m_SessionCreatedBuffer + 56, paddingLen);
+		RAND_bytes (m_SessionCreatedBuffer + 64, paddingLen);
 		// send message		
 		m_SessionCreatedBufferLen = paddingLen + 64;
 		boost::asio::async_write (m_Socket, boost::asio::buffer (m_SessionCreatedBuffer, m_SessionCreatedBufferLen), boost::asio::transfer_all (),
@@ -366,7 +379,7 @@ namespace transport
 			decryption.SetIV (m_Establisher->m_IV);
 			decryption.Decrypt (m_SessionCreatedBuffer, 32, m_Establisher->GetRemotePub ());
 			// decryption key for next block (m_K)
-			m_Establisher->KeyDerivationFunction2 (m_SessionRequestBuffer, m_SessionRequestBufferLen);
+			m_Establisher->KDF2Alice (m_SessionRequestBuffer, m_SessionRequestBufferLen);
 			// decrypt and verify MAC
 			uint8_t payload[16];
 			uint8_t nonce[12];
@@ -386,7 +399,7 @@ namespace transport
 			}
 			else
 			{	
-				LogPrint (eLogWarning, "NTCP2: SessionCreated MAC verification failed ");
+				LogPrint (eLogWarning, "NTCP2: SessionCreated AEAD verification failed ");
 				Terminate ();
 			}	
 		}
@@ -515,7 +528,8 @@ namespace transport
 			// part 1
 			uint8_t nonce[12];
 			CreateNonce (1, nonce);
-			i2p::crypto::AEADChaCha20Poly1305 (m_SessionConfirmedBuffer, 48, h, 32, m_Establisher->GetK (), nonce, m_Establisher->m_RemoteStaticKey, 32, false); // decrypt S
+			if (i2p::crypto::AEADChaCha20Poly1305 (m_SessionConfirmedBuffer, 32, h, 32, m_Establisher->GetK (), nonce, m_Establisher->m_RemoteStaticKey, 32, false)) // decrypt S
+			{
 				// part 2
 				// update AD again
 				memcpy (h + 32, m_SessionConfirmedBuffer, 48);
@@ -524,7 +538,8 @@ namespace transport
 				std::vector<uint8_t> buf(m_Establisher->m3p2Len - 16); // -MAC
 				m_Establisher->KDF3Bob (); 
 				memset (nonce, 0, 12); // set nonce to 0 again
-			i2p::crypto::AEADChaCha20Poly1305 (m_SessionConfirmedBuffer + 48, m_Establisher->m3p2Len, m_Establisher->GetH (), 32, m_Establisher->GetK (), nonce, buf.data (), m_Establisher->m3p2Len - 16, false); // decrypt
+				if (i2p::crypto::AEADChaCha20Poly1305 (m_SessionConfirmedBuffer + 48, m_Establisher->m3p2Len - 16, m_Establisher->GetH (), 32, m_Establisher->GetK (), nonce, buf.data (), m_Establisher->m3p2Len - 16, false)) // decrypt
+				{
 					// process RI
 					if (buf[0] == eNTCP2BlkRouterInfo)
 					{
@@ -554,6 +569,18 @@ namespace transport
 					Established ();
 					ReceiveLength ();
 				}	
+				else
+				{
+					LogPrint (eLogWarning, "NTCP2: SessionConfirmed Part2 AEAD verification failed ");
+					Terminate ();
+				}		
+			}
+			else
+			{	
+				LogPrint (eLogWarning, "NTCP2: SessionConfirmed Part1 AEAD verification failed ");
+				Terminate ();
+			}	
+		}
 	}
 
 	void NTCP2Session::ClientLogin ()
@@ -794,7 +821,7 @@ namespace transport
 							continue;
 						}
 
-						LogPrint (eLogInfo, "NTC2P: Start listening TCP port ", address->port);
+						LogPrint (eLogInfo, "NTCP2: Start listening TCP port ", address->port);
 						auto conn = std::make_shared<NTCP2Session>(*this);
 						m_NTCP2Acceptor->async_accept(conn->GetSocket (), std::bind (&NTCP2Server::HandleAccept, this, conn, std::placeholders::_1));
 					}

libi2pd/NTCP2.h

@@ -44,12 +44,14 @@ namespace transport
 
 		void KDF1Alice ();
 		void KDF1Bob ();
-
-		void MixKey (const uint8_t * inputKeyMaterial, uint8_t * derived);
-		void KeyDerivationFunction1 (const uint8_t * rs, const uint8_t * priv, const uint8_t * pub); // for SessionRequest
-		void KeyDerivationFunction2 (const uint8_t * sessionRequest, size_t sessionRequestLen); // for SessionCreate
+		void KDF2Alice (const uint8_t * sessionRequest, size_t sessionRequestLen);
+		void KDF2Bob (const uint8_t * sessionRequest, size_t sessionRequestLen);
 		void KDF3Alice (); // for SessionConfirmed part 2
 		void KDF3Bob ();
+
+		void MixKey (const uint8_t * inputKeyMaterial, uint8_t * derived);
+		void KeyDerivationFunction1 (const uint8_t * pub, const uint8_t * priv, const uint8_t * rs, const uint8_t * epub); // for SessionRequest, (pub, priv) for DH
+		void KeyDerivationFunction2 (const uint8_t * sessionRequest, size_t sessionRequestLen, const uint8_t * epub); // for SessionCreate
 		void CreateEphemeralKey ();
 
 

libi2pd/RouterContext.cpp

@@ -478,7 +478,7 @@ namespace i2p
 			if (n2k) 
 			{
 				n2k.seekg (0, std::ios::end);
-				len = fk.tellg();
+				len = n2k.tellg();
 				n2k.seekg (0, std::ios::beg);
 				if (len == sizeof (NTCP2PrivateKeys))
 				{

libi2pd/RouterInfo.cpp

@@ -873,6 +873,7 @@ namespace data
 
 	std::shared_ptr<const RouterInfo::Address> RouterInfo::GetAddress (TransportStyle s, bool v4only, bool v6only) const
 	{
+		// TODO: make it more gereric using comparator
 #if (BOOST_VERSION >= 105300)
 		auto addresses = boost::atomic_load (&m_Addresses);
 #else
@@ -889,6 +890,25 @@ namespace data
 		return nullptr;
 	}
 
+	std::shared_ptr<const RouterInfo::Address> RouterInfo::GetNTCP2Address (bool v4only) const
+	{
+		// TODO: implement through GetAddress
+#if (BOOST_VERSION >= 105300)
+		auto addresses = boost::atomic_load (&m_Addresses);
+#else
+		auto addresses = m_Addresses;
+#endif
+		for (const auto& address : *addresses)
+		{
+			if (address->IsPublishedNTCP2 ())
+			{
+				if (!v4only || address->host.is_v4 ())
+					return address;
+			}
+		}
+		return nullptr;
+	}
+
 	std::shared_ptr<RouterProfile> RouterInfo::GetProfile () const
 	{
 		if (!m_Profile)

libi2pd/RouterInfo.h

@@ -142,6 +142,7 @@ namespace data
 			uint64_t GetTimestamp () const { return m_Timestamp; };
 			Addresses& GetAddresses () { return *m_Addresses; }; // should be called for local RI only, otherwise must return shared_ptr
 			std::shared_ptr<const Address> GetNTCPAddress (bool v4only = true) const;
+			std::shared_ptr<const Address> GetNTCP2Address (bool v4only = true) const;
 			std::shared_ptr<const Address> GetSSUAddress (bool v4only = true) const;
 			std::shared_ptr<const Address> GetSSUV6Address () const;