Garlic session per destination

Garlic.cpp

@@ -1,35 +1,77 @@
 #include <inttypes.h>
 #include <map>
 #include <string>
-#include <cryptopp/modes.h>
+#include "ElGamal.h"
-#include <cryptopp/aes.h>
 #include "RouterContext.h"
 #include "Timestamp.h"
-#include "ElGamal.h"
 #include "Garlic.h"
 
 namespace i2p
 {
-	I2NPMessage * WrapI2NPMessage (const uint8_t * encryptionKey, I2NPMessage * msg)
+namespace garlic
 {	
-		CryptoPP::RandomNumberGenerator& rnd = i2p::context.GetRandomNumberGenerator ();
+	GarlicRoutingSession::GarlicRoutingSession (const i2p::data::RoutingDestination * destination, int numTags):
-		// create ElGamal block
+		m_Destination (destination), m_NumTags (numTags), m_NextTag (-1), m_SessionTags (0)
-		ElGamalBlock elGamal;
+	{
-		rnd.GenerateBlock (elGamal.sessionKey, 32); // session key
+		m_Rnd.GenerateBlock (m_SessionKey, 32);
-		rnd.GenerateBlock (elGamal.preIV, 32); // Pre-IV
+		if (m_NumTags > 0)
-		uint8_t iv[32]; // IV is first 16 bytes
+		{	
-		CryptoPP::SHA256().CalculateDigest(iv, elGamal.preIV, 32);
+			m_SessionTags = new uint8_t[m_NumTags*32];
+			for (int i = 0; i < m_NumTags; i++)
+				m_Rnd.GenerateBlock (m_SessionTags + i*32, 32);
+		}	
+	}	
 
-		CryptoPP::CBC_Mode<CryptoPP::AES>::Encryption encryption;
+	GarlicRoutingSession::~GarlicRoutingSession	()
-		encryption.SetKeyWithIV (elGamal.sessionKey, 32, iv); 
+	{	
+		delete[] m_SessionTags;
+	}
 		
+	I2NPMessage * GarlicRoutingSession::WrapSingleMessage (I2NPMessage * msg)
+	{
 		I2NPMessage * m = NewI2NPMessage ();
+		size_t len = 0;
 		uint8_t * buf = m->GetPayload () + 4; // 4 bytes for length
-		i2p::crypto::ElGamalEncrypt (encryptionKey, (uint8_t *)&elGamal, sizeof(elGamal), buf, true);
+		if (m_NextTag < 0) // new session
+		{
+			// create ElGamal block
+			ElGamalBlock elGamal;
+			memcpy (elGamal.sessionKey, m_SessionKey, 32); 
+			m_Rnd.GenerateBlock (elGamal.preIV, 32); // Pre-IV
+			uint8_t iv[32]; // IV is first 16 bytes
+			CryptoPP::SHA256().CalculateDigest(iv, elGamal.preIV, 32); 
+			i2p::crypto::ElGamalEncrypt (m_Destination->GetEncryptionPublicKey (), (uint8_t *)&elGamal, sizeof(elGamal), buf, true);
 			buf += 514;
+			// AES block
+			m_Encryption.SetKeyWithIV (m_SessionKey, 32, iv);
+			len += 514 + CreateAESBlock (buf, msg);	
+		}
+		else // existing session
+		{	
+			// session tag
+			memcpy (buf, m_SessionTags + m_NextTag*32, 32);
+			buf += 32;
+			uint8_t iv[32]; // IV is first 16 bytes
+			CryptoPP::SHA256().CalculateDigest(iv, m_SessionTags + m_NextTag*32, 32);
+			m_Encryption.SetKeyWithIV (m_SessionKey, 32, iv);
+			// AES block
+			len += 32 + CreateAESBlock (buf, msg);
+		}	
+		m_NextTag++;
+		*(uint32_t *)(m->GetPayload ()) = htobe32 (len);
+		m->len += len + 4;
+		FillI2NPMessageHeader (m, eI2NPGarlic);
+		DeleteI2NPMessage (msg);
+		return m;
+	}	
+
+	size_t GarlicRoutingSession::CreateAESBlock (uint8_t * buf, I2NPMessage * msg)
+	{
 		size_t blockSize = 0;
-		*(uint16_t *)buf = 0; // tag count
+		*(uint16_t *)buf = htobe16 (m_NumTags); // tag count
 		blockSize += 2;
+		memcpy (buf + blockSize, m_SessionTags, m_NumTags*32); // tags
+		blockSize += m_NumTags*32;
 		uint32_t * payloadSize = (uint32_t *)(buf + blockSize);
 		blockSize += 4;
 		uint8_t * payloadHash = buf + blockSize;
@@ -43,18 +85,13 @@ namespace i2p
 		size_t rem = blockSize % 16;
 		if (rem)
 			blockSize += (16-rem); //padding
-		encryption.ProcessData(buf, buf, blockSize);
+		m_Encryption.ProcessData(buf, buf, blockSize);
-
+		return blockSize;
-		*(uint32_t *)(m->GetPayload ()) = htobe32 (blockSize + 514);
-		m->len += blockSize + 514 + 4;	
-		FillI2NPMessageHeader (m, eI2NPGarlic);
-		DeleteI2NPMessage (msg);
-		return m;
 	}	
 
-	size_t CreateGarlicPayload (uint8_t * payload, I2NPMessage * msg)
+	size_t GarlicRoutingSession::CreateGarlicPayload (uint8_t * payload, I2NPMessage * msg)
 	{
-		uint64_t ts = i2p::util::GetMillisecondsSinceEpoch ();
+		uint64_t ts = i2p::util::GetMillisecondsSinceEpoch () + 5000; // 5 sec
 		size_t size = 0;
 		payload[size] = 1; // 1 clove
 		size++;
@@ -62,7 +99,7 @@ namespace i2p
 		size++;
 		memcpy (payload + size, msg->GetBuffer (), msg->GetLength ());
 		size += msg->GetLength ();
-		*(uint32_t *)(payload + size) = htobe32 (1011); // CloveID
+		*(uint32_t *)(payload + size) = htobe32 (m_Rnd.GenerateWord32 ()); // CloveID
 		size += 4;
 		*(uint64_t *)(payload + size) = htobe64 (ts); // Expiration of clove
 		size += 8;
@@ -70,10 +107,46 @@ namespace i2p
 		size += 3;
 		memset (payload + size, 0, 3); // certificate of message
 		size += 3;
-		*(uint32_t *)(payload + size) = htobe32 (2022); // MessageID
+		*(uint32_t *)(payload + size) = htobe32 (m_Rnd.GenerateWord32 ()); // MessageID
 		size += 4;
 		*(uint64_t *)(payload + size) = htobe64 (ts); // Expiration of message
 		size += 8;
 		return size;
 	}	
+
+	GarlicRouting routing;	
+	GarlicRouting::GarlicRouting ()
+	{
+	}
+	
+	GarlicRouting::~GarlicRouting ()
+	{
+		for (auto it: m_Sessions)
+			delete it.second;
+		m_Sessions.clear ();
+	}	
+
+	I2NPMessage * GarlicRouting::WrapSingleMessage (const i2p::data::RoutingDestination * destination, I2NPMessage * msg)
+	{
+		if (!destination) return nullptr;
+		std::string dest ((const char *)destination->GetIdentHash (), 32);
+		auto it = m_Sessions.find (dest);
+		GarlicRoutingSession * session = nullptr;
+		if (it != m_Sessions.end ())
+			session = it->second;
+		if (!session)
+		{
+			session = new GarlicRoutingSession (destination, 4); // TODO: change it later
+			m_Sessions[dest] = session;
+		}	
+
+		I2NPMessage * ret = session->WrapSingleMessage (msg);
+		if (session->GetNumRemainingSessionTags () <= 0)
+		{
+			m_Sessions.erase (dest);
+			delete session;
+		}	
+		return ret;
+	}	
+}	
 }

Garlic.h

@@ -2,10 +2,19 @@
 #define GARLIC_H__
 
 #include <inttypes.h>
+#include <map>
+#include <string>
+#include <cryptopp/modes.h>
+#include <cryptopp/aes.h>
+#include <cryptopp/osrng.h>
 #include "I2NPProtocol.h"
+#include "LeaseSet.h"
 
 namespace i2p
 {	
+namespace garlic
+{
+	
 	enum GarlicDeliveryType 
 	{ 
 		eGarlicDeliveryTypeLocal = 0, 
@@ -23,8 +32,48 @@ namespace i2p
 	};		
 #pragma pack()	
 
-	I2NPMessage * WrapI2NPMessage (const uint8_t * encryptionKey, I2NPMessage * msg);
+	
+	class GarlicRoutingSession
+	{
+		public:
+
+			GarlicRoutingSession (const i2p::data::RoutingDestination * destination, int numTags);
+			~GarlicRoutingSession ();
+			I2NPMessage * WrapSingleMessage (I2NPMessage * msg);
+			int GetNumRemainingSessionTags () const { return m_NumTags - m_NextTag; };
+
+		private:
+
+			size_t CreateAESBlock (uint8_t * buf, I2NPMessage * msg);
 			size_t CreateGarlicPayload (uint8_t * payload, I2NPMessage * msg);
+			
+		private:
+
+			const i2p::data::RoutingDestination * m_Destination;
+			uint8_t m_SessionKey[32];
+			int m_NumTags, m_NextTag;
+			uint8_t * m_SessionTags; // m_NumTags*32 bytes
+			
+			CryptoPP::CBC_Mode<CryptoPP::AES>::Encryption m_Encryption;
+			CryptoPP::AutoSeededRandomPool m_Rnd;
+	};	
+
+	class GarlicRouting
+	{
+		public:
+
+			GarlicRouting ();
+			~GarlicRouting ();
+
+			I2NPMessage * WrapSingleMessage (const i2p::data::RoutingDestination * destination, I2NPMessage * msg);
+			
+		private:
+
+			std::map<std::string, GarlicRoutingSession *> m_Sessions;
+	};	
+
+	extern GarlicRouting routing;
+}	
 }
 
 #endif

LeaseSet.cpp

@@ -0,0 +1,33 @@
+#include <cryptopp/sha.h>
+#include "Log.h"
+#include "RouterInfo.h"
+#include "LeaseSet.h"
+
+namespace i2p
+{
+namespace data
+{
+	LeaseSet::LeaseSet (const uint8_t * buf, int len)
+	{
+#pragma pack(1)
+		struct H
+		{
+			RouterIdentity destination;
+			uint8_t encryptionKey[256];
+			uint8_t signingKey[128];
+			uint8_t num;
+		};		
+#pragma pack ()	
+
+		const H * header = (const H *)buf;
+		CryptoPP::SHA256().CalculateDigest(m_IdentHash, (uint8_t *)&header->destination, sizeof (RouterIdentity));
+		memcpy (m_EncryptionKey, header->encryptionKey, 256);
+		LogPrint ("LeaseSet num=", (int)header->num);
+
+		for (int i = 0; i < header->num; i++)
+		{
+			m_Leases.push_back (*(Lease *)(buf + sizeof (H)));
+		}	
+	}	
+}		
+}	

LeaseSet.h

@@ -0,0 +1,46 @@
+#ifndef LEASE_SET_H__
+#define LEASE_SET_H__
+
+#include <inttypes.h>
+#include <list>
+
+namespace i2p
+{
+namespace data
+{
+#pragma pack(1)
+	struct Lease
+	{
+		uint8_t tunnelGateway[32];
+		uint32_t tunnelID;
+		uint64_t endDate;
+	};	
+#pragma pack()	
+
+	class RoutingDestination  // TODO: move to separate file later
+	{
+		public:
+			virtual const uint8_t * GetIdentHash () const = 0;
+			virtual const uint8_t * GetEncryptionPublicKey () const = 0;
+	};	
+	
+	class LeaseSet: public RoutingDestination
+	{
+		public:
+
+			LeaseSet (const uint8_t * buf, int len);
+
+			// implements RoutingDestination
+			const uint8_t * GetIdentHash () const { return m_IdentHash; };
+			const uint8_t * GetEncryptionPublicKey () const { return m_EncryptionKey; };
+			
+		private:
+
+			std::list<Lease> m_Leases;
+			uint8_t m_IdentHash[32];
+			uint8_t m_EncryptionKey[256];
+	};	
+}		
+}	
+
+#endif

RouterInfo.h

@@ -7,6 +7,7 @@
 #include <vector>
 #include <iostream>
 #include <boost/asio.hpp>
+#include "LeaseSet.h"
 
 namespace i2p
 {
@@ -23,7 +24,7 @@ namespace data
 #pragma pack ()	
 	
 	
-	class RouterInfo
+	class RouterInfo: public RoutingDestination
 	{
 		public:
 
@@ -50,7 +51,6 @@ namespace data
 			
 			const RouterIdentity& GetRouterIdentity () const { return m_RouterIdentity; };
 			void SetRouterIdentity (const RouterIdentity& identity);
-			const uint8_t * GetIdentHash () const { return m_IdentHash; };
 			const char * GetIdentHashBase64 () const { return m_IdentHashBase64; };
 			const std::vector<Address>& GetAddresses () const { return m_Addresses; };
 			Address * GetNTCPAddress ();
@@ -68,6 +68,10 @@ namespace data
 			bool IsUpdated () const { return m_IsUpdated; };
 			void SetUpdated (bool updated) { m_IsUpdated = updated; }; 
 
+			// implements RoutingDestination
+			const uint8_t * GetIdentHash () const { return m_IdentHash; };
+			const uint8_t * GetEncryptionPublicKey () const { return m_RouterIdentity.publicKey; };
+			
 		private:
 
 			void ReadFromFile (const char * filename);