handle and publish NTCP2 address

libi2pd/RouterContext.cpp

@@ -2,6 +2,7 @@
 #include <openssl/rand.h>
 #include "Config.h"
 #include "Crypto.h"
+#include "Ed25519.h"
 #include "Timestamp.h"
 #include "I2NPProtocol.h"
 #include "NetDb.hpp"
@@ -49,6 +50,7 @@ namespace i2p
 			port = rand () % (30777 - 9111) + 9111; // I2P network ports range
 		bool ipv4; i2p::config::GetOption("ipv4", ipv4);
 		bool ipv6; i2p::config::GetOption("ipv6", ipv6);
+		bool ntcp2;  i2p::config::GetOption("ntcp2", ntcp2);
 		bool nat;  i2p::config::GetOption("nat", nat);	
 		std::string ifname; i2p::config::GetOption("ifname", ifname);
 		std::string ifname4; i2p::config::GetOption("ifname4", ifname4);
@@ -82,6 +84,11 @@ namespace i2p
 			routerInfo.AddSSUAddress (host.c_str(), port, routerInfo.GetIdentHash ());
 			routerInfo.AddNTCPAddress (host.c_str(), port);
 		}
+		if (ntcp2)
+		{ 
+			NewNTCP2Keys ();
+			routerInfo.AddNTCP2Address (m_NTCP2Keys->staticPublicKey, m_NTCP2Keys->iv);
+		}
 
 		routerInfo.SetCaps (i2p::data::RouterInfo::eReachable |
 			i2p::data::RouterInfo::eSSUTesting | i2p::data::RouterInfo::eSSUIntroducer); // LR, BC
@@ -102,8 +109,11 @@ namespace i2p
 	void RouterContext::NewNTCP2Keys ()
 	{
 		m_NTCP2Keys.reset (new NTCP2PrivateKeys ());
-		RAND_bytes (m_NTCP2Keys->staticKey, 32);
+		RAND_bytes (m_NTCP2Keys->staticPrivateKey, 32);
 		RAND_bytes (m_NTCP2Keys->iv, 16);
+		BN_CTX * ctx = BN_CTX_new ();
+		i2p::crypto::GetEd25519 ()->ScalarMulB (m_NTCP2Keys->staticPrivateKey, m_NTCP2Keys->staticPublicKey, ctx); 
+		BN_CTX_free (ctx);
 		// save
 		std::ofstream fk (i2p::fs::DataDirPath (NTCP2_KEYS), std::ofstream::binary | std::ofstream::out);
 		fk.write ((char *)m_NTCP2Keys.get (), sizeof (NTCP2PrivateKeys)); 
@@ -455,9 +465,13 @@ namespace i2p
 					m_NTCP2Keys.reset (new NTCP2PrivateKeys ());
 					n2k.read ((char *)m_NTCP2Keys.get (), sizeof (NTCP2PrivateKeys));				
 				}	
+				n2k.close ();
 			}
 			if (!m_NTCP2Keys) 
+			{
 				NewNTCP2Keys ();
+				m_RouterInfo.AddNTCP2Address (m_NTCP2Keys->staticPublicKey, m_NTCP2Keys->iv);
+			}
 		}
 
 		return true;

libi2pd/RouterContext.h

@@ -37,7 +37,8 @@ namespace i2p
 
 			struct NTCP2PrivateKeys 
 			{
-				uint8_t staticKey[32];
+				uint8_t staticPublicKey[32];
+				uint8_t staticPrivateKey[32];
 				uint8_t iv[16];
 			};			
 
@@ -58,6 +59,9 @@ namespace i2p
 				return std::shared_ptr<i2p::garlic::GarlicDestination> (this,
 					[](i2p::garlic::GarlicDestination *) {});
 			}
+			const uint8_t * GetNTCP2StaticPublicKey () const { return m_NTCP2Keys ? m_NTCP2Keys->staticPublicKey : nullptr; };
+			const uint8_t * GetNTCP2StaticPrivateKey () const { return m_NTCP2Keys ? m_NTCP2Keys->staticPrivateKey : nullptr; };
+			const uint8_t * GetNTCP2IV () const { return m_NTCP2Keys ? m_NTCP2Keys->iv : nullptr; };
 
 			uint32_t GetUptime () const;
 			uint32_t GetStartupTime () const { return m_StartupTime; };

libi2pd/RouterInfo.cpp

@@ -176,10 +176,14 @@ namespace data
 			auto address = std::make_shared<Address>();
 			s.read ((char *)&address->cost, sizeof (address->cost));
 			s.read ((char *)&address->date, sizeof (address->date));
-			char transportStyle[5];
+			bool isNtcp2 = false;
-			ReadString (transportStyle, 5, s);
+			char transportStyle[6]; 
-			if (!strcmp (transportStyle, "NTCP"))
+			auto transportStyleLen = ReadString (transportStyle, 6, s) - 1;
+			if (!strncmp (transportStyle, "NTCP", 4)) // NTCP or NTCP2
+			{
 				address->transportStyle = eTransportNTCP;
+				if (transportStyleLen > 4 || transportStyle[4] == '2') isNtcp2= true;
+			}
 			else if (!strcmp (transportStyle, "SSU"))
 			{
 				address->transportStyle = eTransportSSU;
@@ -288,7 +292,7 @@ namespace data
 				if (!s) return;
 			}
 			if (introducers) supportedTransports |= eSSUV4; // in case if host is not presented
-			if (supportedTransports)
+			if (supportedTransports && !isNtcp2) // we ignore NTCP2 addresses for now. TODO:
 			{
 				addresses->push_back(address);
 				m_SupportedTransports |= supportedTransports;
@@ -435,7 +439,7 @@ namespace data
 			s.write ((const char *)&address.date, sizeof (address.date));
 			std::stringstream properties;
 			if (address.transportStyle == eTransportNTCP)
-				WriteString ("NTCP", s);
+				WriteString (address.IsNTCP2 () ? "NTCP2" : "NTCP", s);
 			else if (address.transportStyle == eTransportSSU)
 			{
 				WriteString ("SSU", s);
@@ -451,10 +455,13 @@ namespace data
 			else
 				WriteString ("", s);
 
+			if (!address.IsNTCP2 ()) // we don't publish NTCP2 address fow now. TODO: implement
+			{
 				WriteString ("host", properties);
 				properties << '=';
 				WriteString (address.host.to_string (), properties);
 				properties << ';';
+			}
 			if (address.transportStyle == eTransportSSU)
 			{
 				// write introducers if any
@@ -529,10 +536,23 @@ namespace data
 					properties << ';';
 				}
 			}
+
+			if (!address.IsNTCP2 ()) // we don't publish NTCP2 address fow now. TODO: implement
+			{
 				WriteString ("port", properties);
 				properties << '=';
 				WriteString (boost::lexical_cast<std::string>(address.port), properties);
 				properties << ';';
+			}	
+			if (address.IsNTCP2 ())
+			{
+				// publish s and v for NTCP2
+				WriteString ("s", properties); properties << '=';
+				WriteString (address.ntcp2->staticKey.ToBase64 (), properties); properties << ';';
+				WriteString ("v", properties); properties << '=';
+				WriteString ("2", properties); properties << ';';
+				// TODO: publish "i"
+			}	
 
 			uint16_t size = htobe16 (properties.str ().size ());
 			s.write ((char *)&size, sizeof (size));
@@ -668,6 +688,21 @@ namespace data
 		m_Caps |= eSSUIntroducer;
 	}
 
+	void RouterInfo::AddNTCP2Address (const uint8_t * staticKey, const uint8_t * iv)
+	{
+		for (const auto& it: *m_Addresses) // don't insert one more NTCP2
+			if (it->ntcp2) return;
+		auto addr = std::make_shared<Address>();
+		addr->port = 0;
+		addr->transportStyle = eTransportNTCP;
+		addr->cost = 14;
+		addr->date = 0;
+		addr->ntcp2.reset (new NTCP2Ext ());
+		memcpy (addr->ntcp2->staticKey, staticKey, 32);
+		memcpy (addr->ntcp2->iv, iv, 32);	
+		m_Addresses->push_back(std::move(addr));
+	}
+
 	bool RouterInfo::AddIntroducer (const Introducer& introducer)
 	{
 		for (auto& addr : *m_Addresses)

libi2pd/RouterInfo.h

@@ -92,8 +92,8 @@ namespace data
 
 			struct NTCP2Ext
 			{
-				uint8_t staticKey[32];
+				Tag<32> staticKey;
-				uint8_t iv[16];
+				Tag<16> iv;
 			};
 
 			struct Address
@@ -122,6 +122,8 @@ namespace data
 				{
 					return !(*this == other);
 				}
+
+				bool IsNTCP2 () const { return (bool)ntcp2; };
 			};
 			typedef std::list<std::shared_ptr<Address> > Addresses;
 
@@ -143,6 +145,7 @@ namespace data
 
 			void AddNTCPAddress (const char * host, int port);
 			void AddSSUAddress (const char * host, int port, const uint8_t * key, int mtu = 0);
+			void AddNTCP2Address (const uint8_t * staticKey, const uint8_t * iv);
 			bool AddIntroducer (const Introducer& introducer);
 			bool RemoveIntroducer (const boost::asio::ip::udp::endpoint& e);
 			void SetProperty (const std::string& key, const std::string& value); // called from RouterContext only