From: Scott Nadal <scott.nadal@gmail.com>
Date: Wed, 2 May 2012 14:53:33 +0000 (+0100)
Subject: PPCoin: Preliminary checks on proof-of-stake duplicates
X-Git-Tag: v0.4.0-unstable~174
X-Git-Url: https://git.novaco.in/?p=novacoin.git;a=commitdiff_plain;h=80cc04c8aca5ce6ca38dca0e5dc2bf422e570f2d

PPCoin: Preliminary checks on proof-of-stake duplicates
---

diff --git a/src/main.cpp b/src/main.cpp
index 111c2ff..a857edc 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -45,6 +45,7 @@ CMedianFilter<int> cPeerBlockCounts(5, 0); // Amount of blocks that other nodes
 
 map<uint256, CBlock*> mapOrphanBlocks;
 multimap<uint256, CBlock*> mapOrphanBlocksByPrev;
+set<COutPoint> setStakeSeenOrphan;
 
 map<uint256, CDataStream*> mapOrphanTransactions;
 multimap<uint256, CDataStream*> mapOrphanTransactionsByPrev;
@@ -1286,7 +1287,7 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
 
 
 // ppcoin: coinstake must meet hash target according to the protocol:
-// at least one input must meet the formula
+// input 0 must meet the formula
 //     hash(nBits + txPrev.block.nTime + txPrev.offset + txPrev.nTime + txPrev.vout.n + nTime) < bnTarget * nCoinDay
 // this ensures that the chance of getting a coinstake is proportional to the
 // amount of coin age one owns.
@@ -1423,6 +1424,8 @@ bool CBlock::AddToBlockIndex(unsigned int nFile, unsigned int nBlockPos)
     if (!pindexNew)
         return error("AddToBlockIndex() : new CBlockIndex failed");
     map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.insert(make_pair(hash, pindexNew)).first;
+    if (pindexNew->fProofOfStake) 
+        setStakeSeen.insert(pindexNew->prevoutStake);
 
     pindexNew->phashBlock = &((*mi).first);
     map<uint256, CBlockIndex*>::iterator miPrev = mapBlockIndex.find(hashPrevBlock);
@@ -1612,6 +1615,10 @@ bool ProcessBlock(CNode* pfrom, CBlock* pblock)
     if (mapOrphanBlocks.count(hash))
         return error("ProcessBlock() : already have block (orphan) %s", hash.ToString().substr(0,20).c_str());
 
+    // ppcoin: check proof-of-stake
+    if (pblock->IsProofOfStake() && setStakeSeen.count(pblock->GetProofOfStake()))
+        return error("ProcessBlock() : duplicate proof-of-stake (%s) for block %s", pblock->GetProofOfStake().ToString().c_str(), hash.ToString().c_str());
+
     // Preliminary checks
     if (!pblock->CheckBlock())
         return error("ProcessBlock() : CheckBlock FAILED");
@@ -1643,6 +1650,14 @@ bool ProcessBlock(CNode* pfrom, CBlock* pblock)
     {
         printf("ProcessBlock: ORPHAN BLOCK, prev=%s\n", pblock->hashPrevBlock.ToString().substr(0,20).c_str());
         CBlock* pblock2 = new CBlock(*pblock);
+        // ppcoin: check proof-of-stake
+        if (pblock2->IsProofOfStake())
+        {
+            if (setStakeSeenOrphan.count(pblock2->GetProofOfStake()))
+                return error("ProcessBlock() : duplicate proof-of-stake (%s) for orphan block %s", pblock2->GetProofOfStake().ToString().c_str(), hash.ToString().c_str());
+            else
+                setStakeSeenOrphan.insert(pblock2->GetProofOfStake());
+        }
         mapOrphanBlocks.insert(make_pair(hash, pblock2));
         mapOrphanBlocksByPrev.insert(make_pair(pblock2->hashPrevBlock, pblock2));
 
@@ -1670,6 +1685,7 @@ bool ProcessBlock(CNode* pfrom, CBlock* pblock)
             if (pblockOrphan->AcceptBlock())
                 vWorkQueue.push_back(pblockOrphan->GetHash());
             mapOrphanBlocks.erase(pblockOrphan->GetHash());
+            setStakeSeenOrphan.erase(pblockOrphan->GetProofOfStake());
             delete pblockOrphan;
         }
         mapOrphanBlocksByPrev.erase(hashPrev);
diff --git a/src/main.h b/src/main.h
index a7843b5..6d2ead4 100644
--- a/src/main.h
+++ b/src/main.h
@@ -897,6 +897,11 @@ public:
         return !IsProofOfStake();
     }
 
+    COutPoint GetProofOfStake() const
+    {
+        return IsProofOfStake()? vtx[1].vin[0].prevout : COutPoint();
+    }
+
     // ppcoin: get max transaction timestamp
     int64 GetMaxTransactionTime() const
     {
@@ -1273,8 +1278,9 @@ public:
 
     std::string ToString() const
     {
-        return strprintf("CBlockIndex(nprev=%08x, pnext=%08x, nFile=%d, nBlockPos=%-6d nChainTrust=%"PRI64d" nHeight=%d, nCheckpoint=%d, fProofOfStake=%d merkle=%s, hashBlock=%s)",
-            pprev, pnext, nFile, nBlockPos, nChainTrust, nHeight, nCheckpoint, fProofOfStake,
+        return strprintf("CBlockIndex(nprev=%08x, pnext=%08x, nFile=%d, nBlockPos=%-6d nChainTrust=%"PRI64d" nHeight=%d, nCheckpoint=%d, fProofOfStake=%d prevoutStake=(%s) merkle=%s, hashBlock=%s)",
+            pprev, pnext, nFile, nBlockPos, nChainTrust, nHeight, nCheckpoint,
+            fProofOfStake, prevoutStake.ToString().c_str(),
             hashMerkleRoot.ToString().substr(0,10).c_str(),
             GetBlockHash().ToString().substr(0,20).c_str());
     }