create payload

libi2pd/ECIESX25519AEADRatchetSession.cpp

@@ -15,7 +15,6 @@ namespace garlic
     ECIESX25519AEADRatchetSession::ECIESX25519AEADRatchetSession (GarlicDestination * owner):
         GarlicRoutingSession (owner, true)
     {
-        m_EphemeralKeys.GenerateKeys ();
         // TODO : use precalculated hashes
 		static const char protocolName[41] = "Noise_IKelg2+hs2_25519_ChaChaPoly_SHA256"; // 40 bytes
 		SHA256 ((const uint8_t *)protocolName, 40, m_H);
@@ -86,6 +85,7 @@ namespace garlic
 			return false;
 		}
 		if (isStatic) MixHash (buf, len); // h = SHA256(h || ciphertext)
+        m_State = eSessionStateNewSessionReceived;            
 
         HandlePayload (payload.data (), len - 16, handleClove);    
 
@@ -130,6 +130,7 @@ namespace garlic
 
     bool ECIESX25519AEADRatchetSession::NewOutgoingSessionMessage (const uint8_t * payload, size_t len, uint8_t * out, size_t outLen)
     {
+        m_EphemeralKeys.GenerateKeys ();    
         // we are Alice, bpk is m_RemoteStaticKey
         size_t offset = 0;
         if (!i2p::crypto::GetElligator ()->Encode (m_EphemeralKeys.GetPublicKey (), out + offset))
@@ -171,8 +172,42 @@ namespace garlic
 
     std::shared_ptr<I2NPMessage> ECIESX25519AEADRatchetSession::WrapSingleMessage (std::shared_ptr<const I2NPMessage> msg)
     { 
-        // TODO:
+        auto m = NewI2NPMessage ();
+		m->Align (12); // in order to get buf aligned to 16 (12 + 4)
+		uint8_t * buf = m->GetPayload () + 4; // 4 bytes for length
+        auto payload = CreatePayload (msg);  
+        size_t len = payload.size ();
+
+        switch (m_State)
+        {
+            case eSessionStateNew:
+                if (!NewOutgoingSessionMessage (payload.data (), payload.size (), buf, m->maxLen))
                     return nullptr;
+                len += 96;
+            break;
+            default:
+                return nullptr;
+        }
+       
+        htobe32buf (m->GetPayload (), len);
+		m->len += len + 4;
+		m->FillI2NPMessageHeader (eI2NPGarlic);
+		return m;
+    }
+
+    std::vector<uint8_t> ECIESX25519AEADRatchetSession::CreatePayload (std::shared_ptr<const I2NPMessage> msg)
+    {
+        uint16_t cloveSize = msg->GetPayloadLength () + 9 + 1;
+        std::vector<uint8_t> v(cloveSize + 3);
+        uint8_t * payload = v.data ();
+        payload[0] = eECIESx25519BlkGalicClove; // clove type
+        htobe16buf (payload + 1, cloveSize); // size        
+        payload[3] = 0; // flag and delivery instructions
+        payload[4] = msg->GetTypeID (); // I2NP msg type
+        htobe32buf (payload + 5, msg->GetMsgID ()); // msgID     
+        htobe32buf (payload + 9, msg->GetExpiration ()/1000); // expiration in seconds     
+        memcpy (payload + 13, msg->GetPayload (), msg->GetPayloadLength ());
+        return v;
     }    
 }
 }

libi2pd/ECIESX25519AEADRatchetSession.h

@@ -4,6 +4,7 @@
 #include <string.h>
 #include <inttypes.h>
 #include <functional>
+#include <vector>
 #include "Identity.h"
 #include "Crypto.h"
 #include "Garlic.h"
@@ -25,6 +26,12 @@ namespace garlic
 
     class ECIESX25519AEADRatchetSession: public GarlicRoutingSession
     {
+        enum SessionState
+        {
+            eSessionStateNew =0,
+            eSessionStateNewSessionReceived
+        };
+
         public:
 
             typedef std::function<void (const uint8_t * buf, size_t len)> CloveHandler;
@@ -45,11 +52,13 @@ namespace garlic
             void HandlePayload (const uint8_t * buf, size_t len,  CloveHandler& handleClove);
 
             bool NewOutgoingSessionMessage (const uint8_t * payload, size_t len, uint8_t * out, size_t outLen);
+            std::vector<uint8_t> CreatePayload (std::shared_ptr<const I2NPMessage> msg);
 
         private:
 
             uint8_t m_H[32], m_CK[64] /* [chainkey, key] */, m_RemoteStaticKey[32];
             i2p::crypto::X25519Keys m_EphemeralKeys;
+            SessionState m_State = eSessionStateNew;
     };
 }
 }