Add carrot tx proof support (get_tx_proof and check_tx_proof)

src/wallet/wallet2.cpp

@@ -13220,6 +13220,58 @@ std::string wallet2::get_tx_proof(const cryptonote::transaction &tx, const crypt
   std::vector<crypto::public_key> shared_secret;
   std::vector<crypto::signature> sig;
   std::string sig_str;
+  
+  // Carrot proof
+  if (address.m_is_carrot)
+  {
+    std::vector<crypto::key_derivation> derivations;
+    
+    if (is_out)
+    {
+      // Sender has tx_key
+      const size_t num_derivs = 1 + additional_tx_keys.size();
+      derivations.resize(num_derivs);
+      
+      // Main derivation
+      mx25519_pubkey s_sender_receiver_unctx;
+      bool success = carrot::make_carrot_uncontextualized_shared_key_sender(
+        tx_key,
+        address.m_view_public_key,
+        s_sender_receiver_unctx);
+      THROW_WALLET_EXCEPTION_IF(!success, error::wallet_internal_error,
+        "Failed to generate X25519 key derivation for carrot proof (main)");
+      derivations[0] = carrot::raw_byte_convert<crypto::key_derivation>(s_sender_receiver_unctx);
+      
+      // Additional derivations
+      for (size_t i = 0; i < additional_tx_keys.size(); ++i)
+      {
+        mx25519_pubkey additional_s_sender_receiver_unctx;
+        success = carrot::make_carrot_uncontextualized_shared_key_sender(
+          additional_tx_keys[i],
+          address.m_view_public_key,
+          additional_s_sender_receiver_unctx);
+        THROW_WALLET_EXCEPTION_IF(!success, error::wallet_internal_error,
+          "Failed to generate X25519 key derivation for carrot proof (additional)");
+        derivations[i + 1] = carrot::raw_byte_convert<crypto::key_derivation>(additional_s_sender_receiver_unctx);
+      }
+      
+      sig_str = std::string("CarrotOutProofV1");
+    }
+    else
+    {
+      // view key can be used
+      
+      sig_str = std::string("CarrotInProofV1");
+    }
+    
+    // derivation encoding
+    for (size_t i = 0; i < derivations.size(); ++i)
+      sig_str += tools::base58::encode(std::string((const char *)&derivations[i], sizeof(crypto::key_derivation)));
+    
+    return sig_str;
+  }
+  
+  // Legacy proof
   if (is_out)
   {
     const size_t num_sigs = 1 + additional_tx_keys.size();
@@ -13372,6 +13424,44 @@ bool wallet2::check_tx_proof(const crypto::hash &txid, const cryptonote::account
 
 bool wallet2::check_tx_proof(const cryptonote::transaction &tx, const cryptonote::account_public_address &address, bool is_subaddress, const std::string &message, const std::string &sig_str, uint64_t &received) const
 {
+
+  //
+  if (sig_str.substr(0, 6) == "Carrot")
+  {
+    THROW_WALLET_EXCEPTION_IF(!address.m_is_carrot, error::wallet_internal_error,
+      "Carrot proof provided but address is not a carrot address");
+     const bool is_out = sig_str.substr(6, 3) == "Out";
+     std::vector<crypto::key_derivation> derivations(1);
+     const std::string header = is_out ? "CarrotOutProofV1" : "CarrotInProofV1";
+     const size_t header_len = header.size();
+     THROW_WALLET_EXCEPTION_IF(sig_str.size() < header_len || sig_str.substr(0, header_len) != header, error::wallet_internal_error,
+       "Signature header check error");
+    const size_t deriv_len = tools::base58::encode(std::string((const char *)&derivations[0], sizeof(crypto::key_derivation))).size();
+    const size_t num_derivs = (sig_str.size() - header_len) / deriv_len;
+    derivations.resize(num_derivs);
+    
+    // Decode all derivations from base58
+    for (size_t i = 0; i < num_derivs; ++i)
+    {
+      std::string deriv_decoded;
+      const size_t offset = header_len + i * deriv_len;
+      THROW_WALLET_EXCEPTION_IF(!tools::base58::decode(sig_str.substr(offset, deriv_len), deriv_decoded), error::wallet_internal_error,
+        "Derivation decoding error");
+      THROW_WALLET_EXCEPTION_IF(sizeof(crypto::key_derivation) != deriv_decoded.size(), error::wallet_internal_error,
+        "Derivation decoding error");
+      memcpy(&derivations[i], deriv_decoded.data(), sizeof(crypto::key_derivation));
+    }
+
+    std::vector<crypto::key_derivation> additional_derivations(derivations.begin() + 1, derivations.end());
+    check_tx_key_helper(tx, derivations[0], additional_derivations, address, received);
+
+    return true;
+  }  
+
+    // Legacy proof handling
+  THROW_WALLET_EXCEPTION_IF(address.m_is_carrot, error::wallet_internal_error,
+    "Legacy proof provided but address is a carrot address");
+
   // InProofV1, InProofV2, OutProofV1, OutProofV2
   const bool is_out = sig_str.substr(0, 3) == "Out";
   const std::string header = is_out ? sig_str.substr(0,10) : sig_str.substr(0,9);