NTCP2 added

build/CMakeLists.txt

@@ -80,6 +80,7 @@ set (LIBI2PD_SRC
   "${LIBI2PD_SRC_DIR}/ChaCha20.cpp"	
   "${LIBI2PD_SRC_DIR}/Poly1305.cpp"
   "${LIBI2PD_SRC_DIR}/Ed25519.cpp"
+  "${LIBI2PD_SRC_DIR}/NTCP2.cpp"		
 )
 
 if (WITH_WEBSOCKETS)

libi2pd/Ed25519.cpp

@@ -411,6 +411,14 @@ namespace crypto
 		}
 	}
 
+	void Ed25519::ExpandPrivateKey (const uint8_t * key, uint8_t * expandedKey)
+	{
+		SHA512 (key, EDDSA25519_PRIVATE_KEY_LENGTH, expandedKey);
+		expandedKey[0] &= 0xF8; // drop last 3 bits
+		expandedKey[EDDSA25519_PRIVATE_KEY_LENGTH - 1] &= 0x3F; // drop first 2 bits
+		expandedKey[EDDSA25519_PRIVATE_KEY_LENGTH - 1] |= 0x40; // set second bit
+	}
+
 	static std::unique_ptr<Ed25519> g_Ed25519;
 	std::unique_ptr<Ed25519>& GetEd25519 ()
 	{

libi2pd/Ed25519.h

@@ -79,6 +79,8 @@ namespace crypto
 			bool Verify (const EDDSAPoint& publicKey, const uint8_t * digest, const uint8_t * signature) const;
 			void Sign (const uint8_t * expandedPrivateKey, const uint8_t * publicKeyEncoded, const uint8_t * buf, size_t len, uint8_t * signature) const;
 
+			static void ExpandPrivateKey (const uint8_t * key, uint8_t * expandedKey); // key - 32 bytes, expandedKey - 64 bytes
+
 		private:
 
 			EDDSAPoint Sum (const EDDSAPoint& p1, const EDDSAPoint& p2, BN_CTX * ctx) const;

libi2pd/NTCP2.cpp

@@ -0,0 +1,44 @@
+#include <openssl/rand.h>
+#include "Crypto.h"
+#include "Ed25519.h"
+#include "ChaCha20.h"
+#include "Poly1305.h"
+#include "NTCP2.h"
+
+namespace i2p
+{
+namespace transport
+{
+	NTCP2Session::NTCP2Session (std::shared_ptr<const i2p::data::RouterInfo> in_RemoteRouter):
+		TransportSession (in_RemoteRouter, 30)
+	{
+	}
+
+	NTCP2Session::~NTCP2Session ()
+	{
+	}
+
+	void NTCP2Session::CreateEphemeralKey (uint8_t * pub)
+	{
+		uint8_t key[32];
+		RAND_bytes (key, 32);
+		i2p::crypto::Ed25519::ExpandPrivateKey (key, m_ExpandedPrivateKey);
+		BN_CTX * ctx = BN_CTX_new ();
+		auto publicKey = i2p::crypto::GetEd25519 ()->GeneratePublicKey (m_ExpandedPrivateKey, ctx);
+		i2p::crypto::GetEd25519 ()->EncodePublicKey (publicKey, pub, ctx);
+		BN_CTX_free (ctx);
+	}
+
+	void NTCP2Session::SendSessionRequest (const uint8_t * iv)
+	{
+		i2p::crypto::AESAlignedBuffer<32> x;
+		CreateEphemeralKey (x);
+		// encrypt X
+		i2p::crypto::CBCEncryption encryption;
+		encryption.SetKey (GetRemoteIdentity ()->GetIdentHash ());
+		encryption.SetIV (iv);
+		encryption.Encrypt (2, x.GetChipherBlock (), x.GetChipherBlock ());		
+	}	
+}
+}
+

libi2pd/NTCP2.h

@@ -0,0 +1,32 @@
+#ifndef NTCP2_H__
+#define NTCP2_H__
+
+#include <inttypes.h>
+#include <memory>
+#include "RouterInfo.h"
+#include "TransportSession.h"
+
+namespace i2p
+{
+namespace transport
+{
+	class NTCP2Session: public TransportSession, public std::enable_shared_from_this<NTCP2Session>
+	{
+		public:
+
+			NTCP2Session (std::shared_ptr<const i2p::data::RouterInfo> in_RemoteRouter = nullptr); // TODO
+			~NTCP2Session ();
+
+		private:
+
+			void CreateEphemeralKey (uint8_t * pub);
+			void SendSessionRequest (const uint8_t * iv);
+
+		private:
+
+			uint8_t m_ExpandedPrivateKey[64]; // x25519 ephemeral key
+	};
+}
+}
+
+#endif

libi2pd/Signature.cpp

@@ -30,11 +30,7 @@ namespace crypto
 	EDDSA25519Signer::EDDSA25519Signer (const uint8_t * signingPrivateKey, const uint8_t * signingPublicKey)
 	{
 		// expand key
-		SHA512 (signingPrivateKey, EDDSA25519_PRIVATE_KEY_LENGTH, m_ExpandedPrivateKey);
+		Ed25519::ExpandPrivateKey (signingPrivateKey, m_ExpandedPrivateKey);
-		m_ExpandedPrivateKey[0] &= 0xF8; // drop last 3 bits
-		m_ExpandedPrivateKey[EDDSA25519_PRIVATE_KEY_LENGTH - 1] &= 0x3F; // drop first 2 bits
-		m_ExpandedPrivateKey[EDDSA25519_PRIVATE_KEY_LENGTH - 1] |= 0x40; // set second bit
-
 		// generate and encode public key
 		BN_CTX * ctx = BN_CTX_new ();
 		auto publicKey = GetEd25519 ()->GeneratePublicKey (m_ExpandedPrivateKey, ctx);