Double mint fix

src/main.cpp

@@ -1335,6 +1335,7 @@ bool AcceptToMemoryPoolWorker(
     // V3 sigma spends.
     sigma::CSigmaState *sigmaState = sigma::CSigmaState::GetState();
     vector<Scalar> zcSpendSerialsV3;
+    vector<GroupElement> zcMintPubcoinsV3;
     {
         LOCK(pool.cs); // protect pool.mapNextTx
         if (tx.IsZerocoinSpend()) {
@@ -1408,6 +1409,23 @@ bool AcceptToMemoryPoolWorker(
                 }
             }
         }
+
+        BOOST_FOREACH(const CTxOut &txout, tx.vout)
+        {
+            if (txout.scriptPubKey.IsSigmaMint()) {
+                GroupElement pubCoinValue;
+                try {
+                    pubCoinValue = sigma::ParseSigmaMintScript(txout.scriptPubKey);
+                } catch (std::invalid_argument&) {
+                    return state.DoS(100, false, PUBCOIN_NOT_VALIDATE, "bad-txns-zerocoin");
+                }
+                if (!sigmaState->CanAddMintToMempool(pubCoinValue)) {
+                    LogPrintf("AcceptToMemoryPool(): sigma mint with the same value %s is already in the mempool\n", pubCoinValue.tostring());
+                    return state.Invalid(false, REJECT_CONFLICT, "txn-mempool-conflict");
+                }
+                zcMintPubcoinsV3.push_back(pubCoinValue);
+            }
+        }
     }
 
     {
@@ -1833,16 +1851,10 @@ bool AcceptToMemoryPoolWorker(
         }
 #endif
     }
+    if(markZcoinSpendTransactionSerial)
+        sigmaState->AddMintsToMempool(zcMintPubcoinsV3);
 #ifdef ENABLE_WALLET
-    vector<GroupElement> zcMintPubcoinsV3;
     if(tx.IsSigmaMint()){
-        BOOST_FOREACH(const CTxOut &txout, tx.vout)
-        {
-            if(txout.scriptPubKey.IsSigmaMint()){
-                GroupElement pubCoinValue = sigma::ParseSigmaMintScript(txout.scriptPubKey);
-                zcMintPubcoinsV3.push_back(pubCoinValue);
-            }
-        }
         if (zwalletMain) {
             LogPrintf("Updating mint state from Mempool..");
             zwalletMain->GetTracker().UpdateMintStateFromMempool(zcMintPubcoinsV3);
@@ -3172,6 +3184,18 @@ bool ConnectBlock(const CBlock &block, CValidationState &state, CBlockIndex *pin
                 sigmaState->RemoveSpendFromMempool(zcSpendSerial);
             }
        }
+        BOOST_FOREACH(const CTxOut &txout, tx.vout)
+        {
+            if (txout.scriptPubKey.IsSigmaMint()) {
+                GroupElement pubCoinValue;
+                try {
+                    pubCoinValue = sigma::ParseSigmaMintScript(txout.scriptPubKey);
+                } catch (std::invalid_argument&) {
+                    return state.DoS(100, false, PUBCOIN_NOT_VALIDATE, "bad-txns-zerocoin");
+                }
+                sigmaState->RemoveMintFromMempool(pubCoinValue);
+            }
+        }
     }
 
     int64_t nTime6 = GetTimeMicros();

src/sigma.cpp

@@ -1067,6 +1067,16 @@ void CSigmaState::RemoveSpendFromMempool(const Scalar& coinSerial) {
     mempoolCoinSerials.erase(coinSerial);
 }
 
+void CSigmaState::AddMintsToMempool(const vector<GroupElement>& pubCoins){
+    BOOST_FOREACH(const GroupElement& pubCoin, pubCoins){
+        mempoolMints.insert(pubCoin);
+    }
+}
+
+void CSigmaState::RemoveMintFromMempool(const GroupElement& pubCoin){
+    mempoolMints.erase(pubCoin);
+}
+
 uint256 CSigmaState::GetMempoolConflictingTxHash(const Scalar& coinSerial) {
     if (mempoolCoinSerials.count(coinSerial) == 0)
         return uint256();
@@ -1078,10 +1088,15 @@ bool CSigmaState::CanAddSpendToMempool(const Scalar& coinSerial) {
     return !IsUsedCoinSerial(coinSerial) && mempoolCoinSerials.count(coinSerial) == 0;
 }
 
+bool CSigmaState::CanAddMintToMempool(const GroupElement& pubCoin){
+    return mempoolMints.count(pubCoin) == 0;
+}
+
 void CSigmaState::Reset() {
     coinGroups.clear();
     latestCoinIds.clear();
     mempoolCoinSerials.clear();
+    mempoolMints.clear();
     containers.Reset();
 }
 

src/sigma.h

@@ -161,6 +161,8 @@ friend bool BuildSigmaStateFromIndex(CChain *, set<CBlockIndex *> &);
     // Check if there is a conflicting tx in the blockchain or mempool
     bool CanAddSpendToMempool(const Scalar& coinSerial);
 
+    bool CanAddMintToMempool(const GroupElement& pubCoin);
+
     // Add spend into the mempool.
     // Check if there is a coin with such serial in either blockchain or mempool
     bool AddSpendToMempool(const Scalar &coinSerial, uint256 txHash);
@@ -169,12 +171,18 @@ friend bool BuildSigmaStateFromIndex(CChain *, set<CBlockIndex *> &);
     // Check if there is a coin with such serial in either blockchain or mempool
     bool AddSpendToMempool(const vector<Scalar> &coinSerials, uint256 txHash);
 
+    void AddMintsToMempool(const vector<GroupElement>& pubCoins);
+
+    void RemoveMintFromMempool(const GroupElement& pubCoin);
+
     // Get conflicting tx hash by coin serial number
     uint256 GetMempoolConflictingTxHash(const Scalar& coinSerial);
 
     // Remove spend from the mempool (usually as the result of adding tx to the block)
     void RemoveSpendFromMempool(const Scalar& coinSerial);
 
+
+
     static CSigmaState* GetState();
 
     int GetLatestCoinID(sigma::CoinDenomination denomination) const;
@@ -199,6 +207,8 @@ friend bool BuildSigmaStateFromIndex(CChain *, set<CBlockIndex *> &);
     // serials of spends currently in the mempool mapped to tx hashes
     std::unordered_map<Scalar, uint256, CScalarHash> mempoolCoinSerials;
 
+    std::unordered_set<GroupElement> mempoolMints;
+
     std::atomic<bool> surgeCondition;
 
     struct Containers {

src/test/remint_tests.cpp

@@ -46,7 +46,7 @@ BOOST_AUTO_TEST_CASE(remint_basic_test)
 
     string stringError;
     CZerocoinState *zerocoinState = CZerocoinState::GetZerocoinState();
-
+    sigma::CSigmaState *sigmaState = sigma::CSigmaState::GetState();
     CWalletDB walletdb(pwalletMain->strWalletFile);
     std::list<CZerocoinEntry> zcEntries;
     decltype(zerocoinState->usedCoinSerials) tempSerials;
@@ -78,6 +78,7 @@ BOOST_AUTO_TEST_CASE(remint_basic_test)
     BOOST_CHECK_MESSAGE(mempool.size() == 1, "Remint transaction accepted into mempool when shouldn't");
     // Clear mempool serials and retry
     zerocoinState->mempoolCoinSerials.clear();
+    sigmaState->Reset();
     pwalletMain->CommitTransaction(dupSerialTx);
     // Mempool should contain two remint transactions both having the same serial
     BOOST_CHECK(mempool.size() == 2);
@@ -188,7 +189,7 @@ BOOST_AUTO_TEST_CASE(remint_basic_test)
             walletdb.WriteZerocoinEntry(zcEntry);
         }
     }
-    
+
     tempSerials = zerocoinState->usedCoinSerials;
     zerocoinState->usedCoinSerials.clear();
 

src/test/sigma_partialspend_mempool_tests.cpp

@@ -353,4 +353,40 @@ BOOST_AUTO_TEST_CASE(same_serial_in_a_transaction) {
     sigmaState->Reset();
 }
 
+BOOST_AUTO_TEST_CASE(double_mint_into_mempool) {
+        sigma::CSigmaState *sigmaState = sigma::CSigmaState::GetState();
+        string denomination;
+        std::vector<string> denominations = {"0.05", "0.1", "0.5", "1", "10", "25", "100"};
+        const auto& sigmaParams = sigma::Params::get_default();
+        // Create 400-200+1 = 201 new empty blocks. // consensus.nMintV3SigmaStartBlock = 400
+        CreateAndProcessEmptyBlocks(201, scriptPubKey);
+        // foreach denom from denominations
+        for(auto denomination : denominations)
+        {
+            printf("Testing denomination %s\n", denomination.c_str());
+            // Make sure that transactions get to mempool
+            pwalletMain->SetBroadcastTransactions(true);
+            sigma::CoinDenomination denom;
+            sigma:: StringToDenomination(denomination, denom);
+            std::vector<sigma::PrivateCoin> privCoins;
+            privCoins.push_back(sigma::PrivateCoin(sigmaParams, denom));
+
+            vector<CHDMint> vDMints;
+            auto vecSend = CWallet::CreateSigmaMintRecipients(privCoins, vDMints);
+
+            CWalletTx wtx;
+            string stringError = pwalletMain->MintAndStoreSigma(vecSend, privCoins, vDMints, wtx);
+            BOOST_CHECK_MESSAGE(stringError == "", "Mint Failed");
+
+            BOOST_CHECK_MESSAGE(mempool.size() == 1, "Mint not added into mempool");
+            //Try mint with the same coin
+            pwalletMain->MintAndStoreSigma(vecSend, privCoins, vDMints, wtx);
+            //Second mint should not be added into mempool
+            BOOST_CHECK_MESSAGE(mempool.size() == 1, "Double mint added into mempool");
+
+            mempool.clear();
+            sigmaState->Reset();
+        }
+}
+
 BOOST_AUTO_TEST_SUITE_END()