[zPIV][Cleanup] remove ContextualCheckZerocoinMint

random-zebra · random-zebra · commit 334b7603f295 · 2020-02-07T16:39:04.000+01:00
Outright reject mints from mempool. Only verify that they are no longer
accepted after Zerocoin_Block_Public_Spend_Enabled
diff --git a/src/main.cpp b/src/main.cpp
@@ -900,26 +900,6 @@ bool CheckZerocoinMint(const uint256& txHash, const CTxOut& txout, CValidationSt
     return true;
 }
 
-bool ContextualCheckZerocoinMint(const CTransaction& tx, const libzerocoin::PublicCoin& coin, const CBlockIndex* pindex)
-{
-    if (pindex->nHeight >= Params().Zerocoin_Block_Public_Spend_Enabled()) {
-        // Zerocoin MINTs have been disabled
-        return error("%s: Mints disabled at height %d - unable to add pubcoin %s", __func__,
-                pindex->nHeight, coin.getValue().GetHex().substr(0, 10));
-    }
-    if (pindex->nHeight >= Params().Zerocoin_Block_V2_Start() && Params().NetworkID() != CBaseChainParams::TESTNET) {
-        //See if this coin has already been added to the blockchain
-        uint256 txid;
-        int nHeight;
-        if (zerocoinDB->ReadCoinMint(coin.getValue(), txid) && IsTransactionInChain(txid, nHeight))
-            return error("%s: pubcoin %s was already accumulated in tx %s", __func__,
-                         coin.getValue().GetHex().substr(0, 10),
-                         txid.GetHex());
-    }
-
-    return true;
-}
-
 bool isBlockBetweenFakeSerialAttackRange(int nHeight)
 {
     if (Params().NetworkID() != CBaseChainParams::MAIN)
@@ -1283,19 +1263,10 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState& state, const CTransa
                 }
             }
 
-            // Check that zPIV mints (if included) are not already known
-            for (auto& out : tx.vout) {
-                if (!out.IsZerocoinMint())
-                    continue;
-
-                libzerocoin::PublicCoin coin(Params().Zerocoin_Params(false));
-                if (!TxOutToPublicCoin(out, coin, state))
-                    return state.Invalid(error("%s: failed final check of zerocoinmint for tx %s",
-                            __func__, tx.GetHash().GetHex()));
-
-                if (!ContextualCheckZerocoinMint(tx, coin, chainActive.Tip()))
-                    return state.Invalid(error("%s: zerocoin mint failed contextual check", __func__));
-            }
+            // Reject legacy zPIV mints
+            if (!Params().IsRegTestNet() && tx.HasZerocoinMintOutputs())
+                return state.Invalid(error("%s : tried to include zPIV mint output in tx %s",
+                        __func__, tx.GetHash().GetHex()), REJECT_INVALID, "bad-txns-invalid-outputs");
 
             // are the actual inputs available?
             if (!view.HaveInputs(tx))
@@ -1349,10 +1320,7 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState& state, const CTransa
                         __func__, hash.ToString(), nFees, txMinFee), REJECT_INSUFFICIENTFEE, "insufficient fee");
 
             // Require that free transactions have sufficient priority to be mined in the next block.
-            if (tx.HasZerocoinMintOutputs()) {
-                if(nFees < Params().Zerocoin_MintFee() * tx.GetZerocoinMintCount())
-                    return state.DoS(0, false, REJECT_INSUFFICIENTFEE, "insufficient fee for zerocoinmint");
-            } else if (!hasZcSpendInputs && GetBoolArg("-relaypriority", true) && nFees < ::minRelayTxFee.GetFee(nSize) && !AllowFree(view.GetPriority(tx, chainActive.Height() + 1))) {
+            if (!hasZcSpendInputs && GetBoolArg("-relaypriority", true) && nFees < ::minRelayTxFee.GetFee(nSize) && !AllowFree(view.GetPriority(tx, chainActive.Height() + 1))) {
                 return state.DoS(0, false, REJECT_INSUFFICIENTFEE, "insufficient priority");
             }
 
@@ -3027,6 +2995,19 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
             return state.DoS(100, error("ConnectBlock() : zerocoin transactions are currently in maintenance mode"));
         }
 
+        if (tx.HasZerocoinMintOutputs()) {
+            if (pindex->nHeight >= Params().Zerocoin_Block_Public_Spend_Enabled())
+                return state.DoS(100, error("%s: Mints no longer accepted at height %d", __func__, pindex->nHeight));
+            // parse minted coins
+            for (auto& out : tx.vout) {
+                if (!out.IsZerocoinMint()) continue;
+                libzerocoin::PublicCoin coin(Params().Zerocoin_Params(false));
+                if (!TxOutToPublicCoin(out, coin, state))
+                    return state.DoS(100, error("%s: failed final check of zerocoinmint for tx %s", __func__, tx.GetHash().GetHex()));
+                vMints.emplace_back(std::make_pair(coin, tx.GetHash()));
+            }
+        }
+
         if (tx.HasZerocoinSpendInputs()) {
             int nHeightTx = 0;
             uint256 txid = tx.GetHash();
@@ -3073,22 +3054,6 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
                 }
             }
 
-            // Check that zPIV mints are not already known
-            if (tx.HasZerocoinMintOutputs()) {
-                for (auto& out : tx.vout) {
-                    if (!out.IsZerocoinMint())
-                        continue;
-
-                    libzerocoin::PublicCoin coin(Params().Zerocoin_Params(false));
-                    if (!TxOutToPublicCoin(out, coin, state))
-                        return state.DoS(100, error("%s: failed final check of zerocoinmint for tx %s", __func__, tx.GetHash().GetHex()));
-
-                    if (!ContextualCheckZerocoinMint(tx, coin, pindex))
-                        return state.DoS(100, error("%s: zerocoin mint failed contextual check", __func__));
-
-                    vMints.emplace_back(std::make_pair(coin, tx.GetHash()));
-                }
-            }
         } else if (!tx.IsCoinBase()) {
             if (!view.HaveInputs(tx))
                 return state.DoS(100, error("ConnectBlock() : inputs missing/spent"),
@@ -3102,23 +3067,6 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
                 }
             }
 
-            // Check that zPIV mints are not already known
-            if (tx.HasZerocoinMintOutputs()) {
-                for (auto& out : tx.vout) {
-                    if (!out.IsZerocoinMint())
-                        continue;
-
-                    libzerocoin::PublicCoin coin(Params().Zerocoin_Params(false));
-                    if (!TxOutToPublicCoin(out, coin, state))
-                        return state.DoS(100, error("%s: failed final check of zerocoinmint for tx %s", __func__, tx.GetHash().GetHex()));
-
-                    if (!ContextualCheckZerocoinMint(tx, coin, pindex))
-                        return state.DoS(100, error("%s: zerocoin mint failed contextual check", __func__));
-
-                    vMints.emplace_back(std::make_pair(coin, tx.GetHash()));
-                }
-            }
-
             // Add in sigops done by pay-to-script-hash inputs;
             // this is to prevent a "rogue miner" from creating
             // an incredibly-expensive-to-validate block.
