decrypt short request record

libi2pd/I2NPProtocol.h

@@ -101,6 +101,9 @@ namespace i2p
 	const size_t ECIES_BUILD_RESPONSE_RECORD_OPTIONS_OFFSET = 0;
 	const size_t ECIES_BUILD_RESPONSE_RECORD_RET_OFFSET = 511;
 
+	// ShortRequestRecordClearText
+	const size_t SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE = 172;
+	
 	enum I2NPMessageType
 	{
 		eI2NPDummyMsg = 0,

libi2pd/RouterContext.cpp

@@ -875,10 +875,21 @@ namespace i2p
 
 	bool RouterContext::DecryptTunnelBuildRecord (const uint8_t * encrypted, uint8_t * data)
 	{
-		if (!m_TunnelDecryptor) return false;
 		if (IsECIES ())
+			return DecryptECIESTunnelBuildRecord (encrypted, data, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE);
+		else
 		{
-			if (!m_InitialNoiseState) return false;
+			if (!m_TunnelDecryptor) return false;	
+			BN_CTX * ctx = BN_CTX_new ();
+			bool success = m_TunnelDecryptor->Decrypt (encrypted, data, ctx, false);
+			BN_CTX_free (ctx);
+			return success;
+		}
+	}
+
+	bool RouterContext::DecryptECIESTunnelBuildRecord (const uint8_t * encrypted, uint8_t * data, size_t clearTextSize)
+	{	
+		if (!m_InitialNoiseState || !m_TunnelDecryptor) return false;
 		// m_InitialNoiseState is h = SHA256(h || hepk)
 		m_CurrentNoiseState.reset (new i2p::crypto::NoiseSymmetricState (*m_InitialNoiseState));
 		m_CurrentNoiseState->MixHash (encrypted, 32); // h = SHA256(h || sepk)
@@ -892,21 +903,24 @@ namespace i2p
 		encrypted += 32;
 		uint8_t nonce[12];
 		memset (nonce, 0, 12);
-			if (!i2p::crypto::AEADChaCha20Poly1305 (encrypted, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE,
-				m_CurrentNoiseState->m_H, 32, m_CurrentNoiseState->m_CK + 32, nonce, data, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE, false)) // decrypt
+		if (!i2p::crypto::AEADChaCha20Poly1305 (encrypted, clearTextSize, m_CurrentNoiseState->m_H, 32, 
+			m_CurrentNoiseState->m_CK + 32, nonce, data, clearTextSize, false)) // decrypt
 		{
 			LogPrint (eLogWarning, "Router: Tunnel record AEAD decryption failed");
 			return false;
 		}
-			m_CurrentNoiseState->MixHash (encrypted, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE + 16); // h = SHA256(h || ciphertext)
+		m_CurrentNoiseState->MixHash (encrypted, clearTextSize + 16); // h = SHA256(h || ciphertext)
 		return true;
 	}
+
+	bool RouterContext::DecryptTunnelShortRequestRecord (const uint8_t * encrypted, uint8_t * data)
+	{
+		if (IsECIES ())
+			return DecryptECIESTunnelBuildRecord (encrypted, data, SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE);
 		else
 		{
-			BN_CTX * ctx = BN_CTX_new ();
-			bool success = m_TunnelDecryptor->Decrypt (encrypted, data, ctx, false);
-			BN_CTX_free (ctx);
-			return success;
+			LogPrint (eLogWarning, "Router: Can't decrypt short request record on non-ECIES router");
+			return false;
 		}	 
 	}	
 		

libi2pd/RouterContext.h

@@ -97,6 +97,7 @@ namespace garlic
 			int GetNetID () const { return m_NetID; };
 			void SetNetID (int netID) { m_NetID = netID; };
 			bool DecryptTunnelBuildRecord (const uint8_t * encrypted, uint8_t * data);
+			bool DecryptTunnelShortRequestRecord (const uint8_t * encrypted, uint8_t * data);
 			
 			void UpdatePort (int port); // called from Daemon
 			void UpdateAddress (const boost::asio::ip::address& host); // called from SSU or Daemon
@@ -164,6 +165,8 @@ namespace garlic
 			bool Load ();
 			void SaveKeys ();
 
+			bool DecryptECIESTunnelBuildRecord (const uint8_t * encrypted, uint8_t * data, size_t clearTextSize);
+			
 		private:
 
 			i2p::data::RouterInfo m_RouterInfo;