one time garlic encryption for ECIES routers

libi2pd/Destination.cpp

@@ -559,9 +559,7 @@ namespace client
 		m_ExcludedFloodfills.insert (floodfill->GetIdentHash ());
 		LogPrint (eLogDebug, "Destination: Publish LeaseSet of ", GetIdentHash ().ToBase32 ());
 		RAND_bytes ((uint8_t *)&m_PublishReplyToken, 4);
-		auto msg = i2p::CreateDatabaseStoreMsg (leaseSet, m_PublishReplyToken, inbound);
-		if (floodfill->GetIdentity ()->GetCryptoKeyType () == i2p::data::CRYPTO_KEY_TYPE_ELGAMAL) // TODO: remove when implemented
-			msg = WrapMessage (floodfill, msg);
+		auto msg = WrapMessageForRouter (floodfill, i2p::CreateDatabaseStoreMsg (leaseSet, m_PublishReplyToken, inbound));
 		m_PublishConfirmationTimer.expires_from_now (boost::posix_time::seconds(PUBLISH_CONFIRMATION_TIMEOUT));
 		m_PublishConfirmationTimer.async_wait (std::bind (&LeaseSetDestination::HandlePublishConfirmationTimer,
 			shared_from_this (), std::placeholders::_1));
@@ -756,10 +754,8 @@ namespace client
 			else	
 				AddSessionKey (replyKey, replyTag);
 
-			auto msg = CreateLeaseSetDatabaseLookupMsg (dest, request->excluded,
-				request->replyTunnel, replyKey, replyTag, isECIES);
-			if (nextFloodfill->GetIdentity ()->GetCryptoKeyType () == i2p::data::CRYPTO_KEY_TYPE_ELGAMAL) // TODO: remove when implemented
-				msg = WrapMessage (nextFloodfill, msg);
+			auto msg = WrapMessageForRouter (nextFloodfill, CreateLeaseSetDatabaseLookupMsg (dest, request->excluded,
+				request->replyTunnel, replyKey, replyTag, isECIES));
 			request->outboundTunnel->SendTunnelDataMsg (
 				{
 					i2p::tunnel::TunnelMessageBlock

libi2pd/ECIESX25519AEADRatchetSession.cpp

@@ -446,7 +446,7 @@ namespace garlic
 		LogPrint (eLogDebug, "Garlic: new send ratchet ", m_NextSendRatchet->newKey ? "new" : "old", " key ", m_NextSendRatchet->keyID, " created");
 	}
 
-	bool ECIESX25519AEADRatchetSession::NewOutgoingSessionMessage (const uint8_t * payload, size_t len, uint8_t * out, size_t outLen)
+	bool ECIESX25519AEADRatchetSession::NewOutgoingSessionMessage (const uint8_t * payload, size_t len, uint8_t * out, size_t outLen, bool isStatic)
 	{
 		ResetKeys ();
 		// we are Alice, bpk is m_RemoteStaticKey
@@ -464,31 +464,47 @@ namespace garlic
 		uint8_t sharedSecret[32];
 		m_EphemeralKeys->Agree (m_RemoteStaticKey, sharedSecret); // x25519(aesk, bpk)
 		MixKey (sharedSecret);
-		// encrypt static key section
+		// encrypt flags/static key section
 		uint8_t nonce[12];
 		CreateNonce (0, nonce);
-		if (!i2p::crypto::AEADChaCha20Poly1305 (GetOwner ()->GetEncryptionPublicKey (i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD_RATCHET), 32, m_H, 32, m_CK + 32, nonce, out + offset, 48, true)) // encrypt
+		const uint8_t * fs;
+		if (isStatic)
+			fs = GetOwner ()->GetEncryptionPublicKey (i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD_RATCHET);
+		else
+		{
+			memset (out + offset, 0, 32); // all zeros flags section	
+			fs = out + offset;
+		}
+		if (!i2p::crypto::AEADChaCha20Poly1305 (fs, 32, m_H, 32, m_CK + 32, nonce, out + offset, 48, true)) // encrypt
 		{
-			LogPrint (eLogWarning, "Garlic: Static section AEAD encryption failed ");
+			LogPrint (eLogWarning, "Garlic: Flags/static section AEAD encryption failed ");
 			return false;
 		}
+		
 		MixHash (out + offset, 48); // h = SHA256(h || ciphertext)
 		offset += 48;
 		// KDF2
-		GetOwner ()->Decrypt (m_RemoteStaticKey, sharedSecret, nullptr, i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD_RATCHET); // x25519 (ask, bpk)
-		MixKey (sharedSecret); 
+		if (isStatic)
+		{	
+			GetOwner ()->Decrypt (m_RemoteStaticKey, sharedSecret, nullptr, i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD_RATCHET); // x25519 (ask, bpk)
+			MixKey (sharedSecret); 
+		}
+		else
+			CreateNonce (1, nonce);
 		// encrypt payload
 		if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len, m_H, 32, m_CK + 32, nonce, out + offset, len + 16, true)) // encrypt
 		{
 			LogPrint (eLogWarning, "Garlic: Payload section AEAD encryption failed");
 			return false;
 		}
-		MixHash (out + offset, len + 16); // h = SHA256(h || ciphertext)
-
+		
 		m_State = eSessionStateNewSessionSent;
-		if (GetOwner ())
-			GenerateMoreReceiveTags (CreateNewSessionTagset (), ECIESX25519_NSR_NUM_GENERATED_TAGS);
-
+		if (isStatic)
+		{	
+			MixHash (out + offset, len + 16); // h = SHA256(h || ciphertext)
+			if (GetOwner ())
+				GenerateMoreReceiveTags (CreateNewSessionTagset (), ECIESX25519_NSR_NUM_GENERATED_TAGS);
+		}
 		return true;
 	}
 
@@ -778,6 +794,11 @@ namespace garlic
 					return nullptr;
 				len += 72;
 			break;
+			case eSessionStateOneTime:
+				if (!NewOutgoingSessionMessage (payload.data (), payload.size (), buf, m->maxLen, false))
+					return nullptr;
+				len += 96;
+			break;	
 			default:
 				return nullptr;
 		}
@@ -788,6 +809,12 @@ namespace garlic
 		return m;
 	}
 
+	std::shared_ptr<I2NPMessage> ECIESX25519AEADRatchetSession::WrapOneTimeMessage (std::shared_ptr<const I2NPMessage> msg)
+	{
+		m_State = eSessionStateOneTime;
+		return WrapSingleMessage (msg);
+	}	
+		
 	std::vector<uint8_t> ECIESX25519AEADRatchetSession::CreatePayload (std::shared_ptr<const I2NPMessage> msg, bool first)
 	{
 		uint64_t ts = i2p::util::GetMillisecondsSinceEpoch ();

libi2pd/ECIESX25519AEADRatchetSession.h

@@ -31,7 +31,7 @@ namespace garlic
 	const int ECIESX25519_SEND_INACTIVITY_TIMEOUT = 5000; // number of milliseconds we can send empty(pyaload only) packet after 
 	const int ECIESX25519_INCOMING_TAGS_EXPIRATION_TIMEOUT = 600; // in seconds
 	const int ECIESX25519_PREVIOUS_TAGSET_EXPIRATION_TIMEOUT = 180; // 180
-	const int ECIESX25519_TAGSET_MAX_NUM_TAGS = 4096; // number of tags we request new tagset after
+	const int ECIESX25519_TAGSET_MAX_NUM_TAGS = 8192; // number of tags we request new tagset after
 	const int ECIESX25519_MIN_NUM_GENERATED_TAGS = 24;
 	const int ECIESX25519_MAX_NUM_GENERATED_TAGS = 160;
 	const int ECIESX25519_NSR_NUM_GENERATED_TAGS = 12;
@@ -129,7 +129,9 @@ namespace garlic
 	const uint8_t ECIESX25519_NEXT_KEY_REVERSE_KEY_FLAG = 0x02;
 	const uint8_t ECIESX25519_NEXT_KEY_REQUEST_REVERSE_KEY_FLAG = 0x04;
 
-	class ECIESX25519AEADRatchetSession: public GarlicRoutingSession, public std::enable_shared_from_this<ECIESX25519AEADRatchetSession>
+	class ECIESX25519AEADRatchetSession: public GarlicRoutingSession, 
+		private i2p::crypto::NoiseSymmetricState,
+		public std::enable_shared_from_this<ECIESX25519AEADRatchetSession>
 	{
 		enum SessionState
 		{
@@ -137,7 +139,8 @@ namespace garlic
 			eSessionStateNewSessionReceived,
 			eSessionStateNewSessionSent,
 			eSessionStateNewSessionReplySent,
-			eSessionStateEstablished
+			eSessionStateEstablished,
+			eSessionStateOneTime
 		};
 
 		struct DHRatchet
@@ -155,7 +158,8 @@ namespace garlic
 
 			bool HandleNextMessage (uint8_t * buf, size_t len, std::shared_ptr<RatchetTagSet> receiveTagset, int index = 0);
 			std::shared_ptr<I2NPMessage> WrapSingleMessage (std::shared_ptr<const I2NPMessage> msg);
-
+			std::shared_ptr<I2NPMessage> WrapOneTimeMessage (std::shared_ptr<const I2NPMessage> msg);
+			
 			const uint8_t * GetRemoteStaticKey () const { return m_RemoteStaticKey; }
 			void SetRemoteStaticKey (const uint8_t * key) { memcpy (m_RemoteStaticKey, key, 32); }
 
@@ -175,7 +179,6 @@ namespace garlic
 		private:
 
 			void ResetKeys ();
-			void MixHash (const uint8_t * buf, size_t len);
 			void CreateNonce (uint64_t seqn, uint8_t * nonce);
 			bool GenerateEphemeralKeysAndEncode (uint8_t * buf); // buf is 32 bytes
 			std::shared_ptr<RatchetTagSet> CreateNewSessionTagset ();
@@ -186,7 +189,7 @@ namespace garlic
 			void HandlePayload (const uint8_t * buf, size_t len, const std::shared_ptr<RatchetTagSet>& receiveTagset, int index);
 			void HandleNextKey (const uint8_t * buf, size_t len, const std::shared_ptr<RatchetTagSet>& receiveTagset);
 
-			bool NewOutgoingSessionMessage (const uint8_t * payload, size_t len, uint8_t * out, size_t outLen);
+			bool NewOutgoingSessionMessage (const uint8_t * payload, size_t len, uint8_t * out, size_t outLen, bool isStatic = true);
 			bool NewSessionReplyMessage (const uint8_t * payload, size_t len, uint8_t * out, size_t outLen);
 			bool NextNewSessionReplyMessage (const uint8_t * payload, size_t len, uint8_t * out, size_t outLen);
 			bool NewExistingSessionMessage (const uint8_t * payload, size_t len, uint8_t * out, size_t outLen);
@@ -200,7 +203,7 @@ namespace garlic
 
 		private:
 
-			uint8_t m_H[32], m_CK[64] /* [chainkey, key] */, m_RemoteStaticKey[32];
+			uint8_t m_RemoteStaticKey[32];
 			uint8_t m_Aepk[32]; // Alice's ephemeral keys, for incoming only
 			uint8_t m_NSREncodedKey[32], m_NSRH[32], m_NSRKey[32]; // new session reply, for incoming only
 			std::shared_ptr<i2p::crypto::X25519Keys> m_EphemeralKeys;

libi2pd/Garlic.cpp

@@ -709,11 +709,20 @@ namespace garlic
 		}
 	}
 
-	std::shared_ptr<I2NPMessage> GarlicDestination::WrapMessage (std::shared_ptr<const i2p::data::RoutingDestination> destination,
-		std::shared_ptr<I2NPMessage> msg, bool attachLeaseSet)
+	std::shared_ptr<I2NPMessage> GarlicDestination::WrapMessageForRouter (std::shared_ptr<const i2p::data::RouterInfo> router,
+		std::shared_ptr<I2NPMessage> msg)
 	{
-		auto session = GetRoutingSession (destination, attachLeaseSet);
-		return session->WrapSingleMessage (msg);
+		if (router->GetEncryptionType () == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD_RATCHET)
+		{
+			auto session = std::make_shared<ECIESX25519AEADRatchetSession>(this, false);
+			session->SetRemoteStaticKey (router->GetIdentity ()->GetEncryptionPublicKey ());
+			return session->WrapOneTimeMessage (msg);
+		}	
+		else
+		{	
+			auto session = GetRoutingSession (router, false);
+			return session->WrapSingleMessage (msg);
+		}	
 	}
 
 	std::shared_ptr<GarlicRoutingSession> GarlicDestination::GetRoutingSession (

libi2pd/Garlic.h

@@ -238,8 +238,8 @@ namespace garlic
 			std::shared_ptr<GarlicRoutingSession> GetRoutingSession (std::shared_ptr<const i2p::data::RoutingDestination> destination, bool attachLeaseSet);
 			void CleanupExpiredTags ();
 			void RemoveDeliveryStatusSession (uint32_t msgID);
-			std::shared_ptr<I2NPMessage> WrapMessage (std::shared_ptr<const i2p::data::RoutingDestination> destination,
-				std::shared_ptr<I2NPMessage> msg, bool attachLeaseSet = false);
+			std::shared_ptr<I2NPMessage> WrapMessageForRouter (std::shared_ptr<const i2p::data::RouterInfo> router,
+				std::shared_ptr<I2NPMessage> msg);
 
 			void AddSessionKey (const uint8_t * key, const uint8_t * tag); // one tag
 			void AddECIESx25519Key (const uint8_t * key, const uint8_t * tag); // one tag