Fix zawy attack

src/komodo_bitcoind.h

@@ -1425,7 +1425,7 @@ arith_uint256 komodo_adaptivepow_target(int32_t height,arith_uint256 bnTarget,ui
         tipdiff = (nTime - tipindex->nTime);
         if ( tipdiff > 13*ASSETCHAINS_BLOCKTIME )
             diff = tipdiff;
-        if ( diff >= 13 * ASSETCHAINS_BLOCKTIME )
+        if ( diff >= 13 * ASSETCHAINS_BLOCKTIME && (height < 3000 || tipdiff > 2*ASSETCHAINS_BLOCKTIME) )
         {
             mult = diff - 12 * ASSETCHAINS_BLOCKTIME;
             mult = (mult / ASSETCHAINS_BLOCKTIME) * ASSETCHAINS_BLOCKTIME + ASSETCHAINS_BLOCKTIME / 2;

src/main.cpp

@@ -5288,7 +5288,7 @@ bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& sta
     }
 
     // Check timestamp against prev
-    if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast())
+    if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast() + 2*ASSETCHAINS_ADAPTIVEPOW*ASSETCHAINS_BLOCKTIME )
     {
         return state.Invalid(error("%s: block's timestamp is too early", __func__),
                         REJECT_INVALID, "time-too-old");

src/miner.cpp

@@ -123,7 +123,7 @@ public:
 
 void UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev)
 {
-    pblock->nTime = std::max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
+    pblock->nTime = std::max(pindexPrev->GetMedianTimePast()+1 + 2*ASSETCHAINS_ADAPTIVEPOW*ASSETCHAINS_BLOCKTIME, GetAdjustedTime());
 
     // Updating time can change work required on testnet:
     if (consensusParams.nPowAllowMinDifficultyBlocksAfterHeight != boost::none) {
@@ -567,7 +567,7 @@ CBlockTemplate* CreateNewBlock(CPubKey _pk,const CScript& _scriptPubKeyIn, int32
 
         nLastBlockTx = nBlockTx;
         nLastBlockSize = nBlockSize;
-        blocktime = 1 + std::max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
+        blocktime = 1 + std::max(pindexPrev->GetMedianTimePast()+1+ 2*ASSETCHAINS_ADAPTIVEPOW*ASSETCHAINS_BLOCKTIME, GetAdjustedTime());
         //pblock->nTime = blocktime + 1;
         pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, Params().GetConsensus());
 
@@ -596,8 +596,6 @@ CBlockTemplate* CreateNewBlock(CPubKey _pk,const CScript& _scriptPubKeyIn, int32
             else
             {
                 blocktime = GetAdjustedTime();
-                //if ( blocktime > pindexPrev->GetMedianTimePast()+60 )
-                //    blocktime = pindexPrev->GetMedianTimePast() + 60;
                 siglen = komodo_staked(txStaked, pblock->nBits, &blocktime, &txtime, &utxotxid, &utxovout, &utxovalue, utxosig);
                 // if you skip this check it will create a block too far into the future and not pass ProcessBlock or AcceptBlock.
                 // This has been moved from the mining loop to save CPU, and to also make ac_staked work with the verus miner.
@@ -642,7 +640,7 @@ CBlockTemplate* CreateNewBlock(CPubKey _pk,const CScript& _scriptPubKeyIn, int32
         txNew.vout[0].nValue = GetBlockSubsidy(nHeight,consensusParams) + nFees;
         //fprintf(stderr,"mine ht.%d with %.8f\n",nHeight,(double)txNew.vout[0].nValue/COIN);
         txNew.nExpiryHeight = 0;
-        txNew.nLockTime = std::max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
+        txNew.nLockTime = std::max(pindexPrev->GetMedianTimePast()+1+ 2*ASSETCHAINS_ADAPTIVEPOW*ASSETCHAINS_BLOCKTIME, GetAdjustedTime());
 
         if ( ASSETCHAINS_SYMBOL[0] == 0 && IS_KOMODO_NOTARY != 0 && My_notaryid >= 0 )
             txNew.vout[0].nValue += 5000;