support multiple encryption keys through the I2CP

libi2pd/Crypto.cpp

@@ -375,15 +375,22 @@ namespace crypto
 #endif
 	}
 
-	void X25519Keys::SetPrivateKey (const uint8_t * priv)
+	void X25519Keys::SetPrivateKey (const uint8_t * priv, bool calculatePublic)
 	{
 #if OPENSSL_X25519
 		if (m_Ctx) EVP_PKEY_CTX_free (m_Ctx);
 		if (m_Pkey) EVP_PKEY_free (m_Pkey);
 		m_Pkey = EVP_PKEY_new_raw_private_key (EVP_PKEY_X25519, NULL, priv, 32);
 		m_Ctx = EVP_PKEY_CTX_new (m_Pkey, NULL);
+		if (calculatePublic)
+		{
+			size_t len = 32;
+			EVP_PKEY_get_raw_public_key (m_Pkey, m_PublicKey, &len);
+		}	
 #else
 		memcpy (m_PrivateKey, priv, 32);
+		if (calculatePublic)
+			GetEd25519 ()->ScalarMulB (m_PrivateKey, m_PublicKey, m_Ctx);
 #endif
 	}
 

libi2pd/Crypto.h

@@ -88,7 +88,7 @@ namespace crypto
 			void GenerateKeys ();
 			const uint8_t * GetPublicKey () const { return m_PublicKey; };
 			void GetPrivateKey (uint8_t * priv) const;
-			void SetPrivateKey (const uint8_t * priv); // wihout calculating public
+			void SetPrivateKey (const uint8_t * priv, bool calculatePublic = false);
 			void Agree (const uint8_t * pub, uint8_t * shared);
 
 		private:

libi2pd/CryptoKey.cpp

@@ -166,7 +166,7 @@ namespace crypto
 		memcpy (pub, m_PublicKey, 32);
 	}
 
-	ECIESX25519AEADRatchetDecryptor::ECIESX25519AEADRatchetDecryptor (const uint8_t * priv)
+	ECIESX25519AEADRatchetDecryptor::ECIESX25519AEADRatchetDecryptor (const uint8_t * priv, bool calculatePublic)
 	{
 		m_StaticKeys.SetPrivateKey (priv);
 	}

libi2pd/CryptoKey.h

@@ -145,11 +145,12 @@ namespace crypto
 	{
 		public:
 
-			ECIESX25519AEADRatchetDecryptor (const uint8_t * priv);
+			ECIESX25519AEADRatchetDecryptor (const uint8_t * priv, bool calculatePublic = false);
 			~ECIESX25519AEADRatchetDecryptor () {};
 			bool Decrypt (const uint8_t * epub, uint8_t * sharedSecret, BN_CTX * ctx, bool zeroPadding);
 			// agree with static and return in sharedSecret (32 bytes)
 			size_t GetPublicKeyLen () const { return 32; };
+			const uint8_t * GetPubicKey () const { return m_StaticKeys.GetPublicKey (); };
 
 		private:
 

libi2pd_client/I2CP.cpp

@@ -55,12 +55,18 @@ namespace client
 
 	void I2CPDestination::SetEncryptionPrivateKey (const uint8_t * key)
 	{
-		memcpy (m_EncryptionPrivateKey, key, 256);
-		m_Decryptor = i2p::data::PrivateKeys::CreateDecryptor (m_Identity->GetCryptoKeyType (), m_EncryptionPrivateKey);
+		m_Decryptor = i2p::data::PrivateKeys::CreateDecryptor (m_Identity->GetCryptoKeyType (), key);
 	}
 
+	void I2CPDestination::SetECIESx25519EncryptionPrivateKey (const uint8_t * key)
+	{
+		m_ECIESx25519Decryptor = std::make_shared<i2p::crypto::ECIESX25519AEADRatchetDecryptor>(key, true); // calculate public
+	}	
+		
 	bool I2CPDestination::Decrypt (const uint8_t * encrypted, uint8_t * data, BN_CTX * ctx, i2p::data::CryptoKeyType preferredCrypto) const
 	{
+		if (preferredCrypto == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD_RATCHET && m_ECIESx25519Decryptor)
+			return m_ECIESx25519Decryptor->Decrypt (encrypted, data, ctx, true);
 		if (m_Decryptor)
 			return m_Decryptor->Decrypt (encrypted, data, ctx, true);
 		else
@@ -68,6 +74,19 @@ namespace client
 		return false;
 	}
 
+	const uint8_t * I2CPDestination::GetEncryptionPublicKey (i2p::data::CryptoKeyType keyType) const
+	{
+		if (keyType == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD_RATCHET && m_ECIESx25519Decryptor)
+			return m_ECIESx25519Decryptor->GetPubicKey ();
+		return nullptr;
+	}	
+
+	bool I2CPDestination::SupportsEncryptionType (i2p::data::CryptoKeyType keyType) const 
+	{ 
+		return keyType == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD_RATCHET ? (bool)m_ECIESx25519Decryptor : m_EncryptionKeyType == keyType; 
+	}
+	
+		
 	void I2CPDestination::HandleDataMessage (const uint8_t * buf, size_t len)
 	{
 		uint32_t length = bufbe32toh (buf);
@@ -77,7 +96,8 @@ namespace client
 
 	void I2CPDestination::CreateNewLeaseSet (std::vector<std::shared_ptr<i2p::tunnel::InboundTunnel> > tunnels)
 	{
-		i2p::data::LocalLeaseSet ls (m_Identity, m_EncryptionPrivateKey, tunnels); // we don't care about encryption key
+		uint8_t priv[256] = {0};
+		i2p::data::LocalLeaseSet ls (m_Identity, priv, tunnels); // we don't care about encryption key, we need leases only
 		m_LeaseSetExpirationTime = ls.GetExpirationTime ();
 		uint8_t * leases = ls.GetLeases ();
 		leases[-1] = tunnels.size ();
@@ -572,28 +592,22 @@ namespace client
 				offset += ls.GetBufferLen ();
 				// private keys
 				int numPrivateKeys = buf[offset]; offset++;
-				uint16_t currentKeyType = 0;
-				const uint8_t * currentKey = nullptr;
 				for (int i = 0; i < numPrivateKeys; i++)
 				{
 					if (offset + 4 > len) return;
 					uint16_t keyType = bufbe16toh (buf + offset); offset += 2; // encryption type
 					uint16_t keyLen = bufbe16toh (buf + offset); offset += 2;  // private key length
 					if (offset + keyLen > len) return;
-					if (!currentKey || keyType > currentKeyType)
+					if (keyType == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD_RATCHET)
+						m_Destination->SetECIESx25519EncryptionPrivateKey (buf + offset);
+					else
 					{
-						currentKeyType = keyType;
-						currentKey = buf + offset;
+						m_Destination->SetEncryptionType (keyType);	
+						m_Destination->SetEncryptionPrivateKey (buf + offset);
 					}
 					offset += keyLen;
 				}
-				// TODO: support multiple keys
-				if (currentKey)
-				{
-					m_Destination->SetEncryptionPrivateKey (currentKey);
-					m_Destination->SetEncryptionType (currentKeyType);
-				}
-
+	
 				m_Destination->LeaseSet2Created (storeType, ls.GetBuffer (), ls.GetBufferLen ());
 			}
 		}

libi2pd_client/I2CP.h

@@ -75,14 +75,15 @@ namespace client
 
 			void SetEncryptionPrivateKey (const uint8_t * key);
 			void SetEncryptionType (i2p::data::CryptoKeyType keyType) { m_EncryptionKeyType = keyType; };
+			void SetECIESx25519EncryptionPrivateKey (const uint8_t * key);
 			void LeaseSetCreated (const uint8_t * buf, size_t len); // called from I2CPSession
 			void LeaseSet2Created (uint8_t storeType, const uint8_t * buf, size_t len); // called from I2CPSession
 			void SendMsgTo (const uint8_t * payload, size_t len, const i2p::data::IdentHash& ident, uint32_t nonce); // called from I2CPSession
 
 			// implements LocalDestination
 			bool Decrypt (const uint8_t * encrypted, uint8_t * data, BN_CTX * ctx, i2p::data::CryptoKeyType preferredCrypto) const;
-			bool SupportsEncryptionType (i2p::data::CryptoKeyType keyType) const { return m_EncryptionKeyType == keyType; };
-			// TODO: implement GetEncryptionPublicKey
+			bool SupportsEncryptionType (i2p::data::CryptoKeyType keyType) const;			
+			const uint8_t * GetEncryptionPublicKey (i2p::data::CryptoKeyType keyType) const; // for 4 only
 			std::shared_ptr<const i2p::data::IdentityEx> GetIdentity () const { return m_Identity; };
 
 		protected:
@@ -101,9 +102,9 @@ namespace client
 
 			std::shared_ptr<I2CPSession> m_Owner;
 			std::shared_ptr<const i2p::data::IdentityEx> m_Identity;
-			uint8_t m_EncryptionPrivateKey[256];
 			i2p::data::CryptoKeyType m_EncryptionKeyType;
-			std::shared_ptr<i2p::crypto::CryptoKeyDecryptor> m_Decryptor;
+			std::shared_ptr<i2p::crypto::CryptoKeyDecryptor> m_Decryptor; // standard
+			std::shared_ptr<i2p::crypto::ECIESX25519AEADRatchetDecryptor> m_ECIESx25519Decryptor;
 			uint64_t m_LeaseSetExpirationTime;
 	};