Supported Cryptonight Variant 4.

src/consensus/params.h

@@ -75,6 +75,7 @@ struct Params {
     int64_t DifficultyAdjustmentInterval() const { return nPowTargetTimespan / nPowTargetSpacing; }
     uint256 nMinimumChainWork;
     uint256 defaultAssumeValid;
+    uint8_t GetCryptonoteMajorVersion() const { return 10; }
 };
 } // namespace Consensus
 

src/miner.cpp

@@ -175,7 +175,7 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
     pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
     UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev);
     pblock->nBits          = GetNextWorkRequired(pindexPrev, pblock, chainparams.GetConsensus());
-    pblock->nNonce         = 0;
+    pblock->nNonce         = nHeight; // nNonce now holds the height for Cryptonight variant 4
     pblocktemplate->vTxSigOpsCost[0] = WITNESS_SCALE_FACTOR * GetLegacySigOpCount(*pblock->vtx[0]);
 
     CValidationState state;

src/primitives/block.cpp

@@ -48,7 +48,7 @@ uint256 CBlockHeader::GetPoWHash() const
     uint256 thash;
     if (hashPrevBlock.IsNull()) {
         // Genesis block
-        cn_slow_hash(BEGIN(nVersion), 80, BEGIN(thash), 2, 0, 0);
+        cn_slow_hash(BEGIN(nVersion), 80, BEGIN(thash), 4, 0, 0);
         return thash;
     }
 
@@ -60,7 +60,7 @@ uint256 CBlockHeader::GetPoWHash() const
         return thash;
     }
     cryptonote::blobdata blob = cryptonote::t_serializable_object_to_blob(cnHeader);
-    cn_slow_hash(blob.data(), blob.size(), BEGIN(thash), 2, 0, 0);
+    cn_slow_hash(blob.data(), blob.size(), BEGIN(thash), cnHeader.major_version - 6, 0, nNonce);
     return thash;
 }
 

src/primitives/block.h

@@ -124,6 +124,8 @@ public:
     uint256 hashMerkleRoot;
     uint32_t nTime;
     uint32_t nBits;
+    // nNonce is no longer used as nonce, as the nonce is now in cnHeader.
+    // Repurpose it for block height used in Cryptnight variant 4.
     uint32_t nNonce;
 
     // CryptoNote header for emulation or merged mining

src/rpc/mining.cpp

@@ -477,7 +477,6 @@ UniValue getblocktemplate(const JSONRPCRequest& request)
 
     // Update nTime
     UpdateTime(pblock, consensusParams, pindexPrev);
-    pblock->nNonce = 0;
 
     std::set<std::string> setClientRules;
     UniValue aRules(UniValue::VARR);
@@ -530,7 +529,7 @@ UniValue getblocktemplate(const JSONRPCRequest& request)
     cryptonote::block cn_block;
     // block_header
     // const int cn_variant = b.major_version >= 7 ? b.major_version - 6 : 0;
-    cn_block.major_version = 8; // cn variant 2
+    cn_block.major_version = consensusParams.GetCryptonoteMajorVersion();
     cn_block.minor_version = 0;
     cn_block.timestamp = pblock->GetBlockTime();
     // The prev_id is used to store kevacoin block hash, as a proof of work.

src/validation.cpp

@@ -1839,6 +1839,11 @@ bool CChainState::ConnectBlock(const CBlock& block, CValidationState& state, CBl
            (*pindex->phashBlock == block.GetHash()));
     int64_t nTimeStart = GetTimeMicros();
 
+    // Check the height of the block is the same as its height on the blockchain.
+    // Note: nNonce now holds the value of height. It is no longer used as nonce.
+    if (block.nNonce != pindex->nHeight)
+        return error("%s: block height mismatch", __func__);
+
     // Check it again in case a previous version let a bad block in
     // NOTE: We don't currently (re-)invoke ContextualCheckBlock() or
     // ContextualCheckBlockHeader() here. This means that if we add a new