map<COutPoint, CInPoint> mapNextTx;
map<uint256, CBlockIndex*> mapBlockIndex;
+set<pair<COutPoint, unsigned int> > setStakeSeen;
uint256 hashGenesisBlock("0x000000006d52486334316794cc38ffeb7ebf35a7ebd661fd39f5f46b0d001575");
static CBigNum bnProofOfWorkLimit(~uint256(0) >> 32);
const int nInitialBlockThreshold = 120; // Regard blocks up until N-threshold as "initial download"
map<uint256, CBlock*> mapOrphanBlocks;
multimap<uint256, CBlock*> mapOrphanBlocksByPrev;
+set<pair<COutPoint, unsigned int> > setStakeSeenOrphan;
map<uint256, CDataStream*> mapOrphanTransactions;
multimap<uint256, CDataStream*> mapOrphanTransactionsByPrev;
// Check for negative or overflow output values
int64 nValueOut = 0;
- for (int i = (IsCoinStake()? 1 : 0); i < vout.size(); i++)
+ for (int i = 0; i < vout.size(); i++)
{
const CTxOut& txout = vout[i];
+ if (txout.IsEmpty() && (!IsCoinBase()) && (!IsCoinStake()))
+ return DoS(100, error("CTransaction::CheckTransaction() : txout empty for user transaction"));
if (txout.nValue < 0)
return DoS(100, error("CTransaction::CheckTransaction() : txout.nValue negative"));
if (txout.nValue > MAX_MONEY)
return nSubsidy;
}
-static const int64 nTargetTimespan = 7 * 24 * 60 * 60; // one week
-static const int64 nTargetSpacing = 10 * 60;
-static const int64 nInterval = nTargetTimespan / nTargetSpacing;
-static const int64 nMaxClockDrift = 2 * 60 * 60; // 2 hours
+static const int64 nTargetTimespan = 7 * 24 * 60 * 60; // one week
+static const int64 nTargetSpacingStake = 10 * 60; // ten minutes
+static const int64 nTargetSpacingWorkMax = 2 * 60 * 60; // two hours
+static const int64 nMaxClockDrift = 2 * 60 * 60; // two hours
//
// minimum amount of work that could possibly be required nTime after
// ppcoin: target change every block
// ppcoin: retarget with exponential moving toward target spacing
CBigNum bnNew;
- bnNew.SetCompact(pindexLast->nBits);
+ bnNew.SetCompact(pindexPrev->nBits);
+ int64 nTargetSpacing = fProofOfStake? nTargetSpacingStake : min(nTargetSpacingWorkMax, nTargetSpacingStake * (1 + pindexLast->nHeight - pindexPrev->nHeight));
+ int64 nInterval = nTargetTimespan / nTargetSpacing;
bnNew *= ((nInterval - 1) * nTargetSpacing + nActualSpacing + nActualSpacing);
bnNew /= ((nInterval + 1) * nTargetSpacing);
if (!CheckBlock())
return false;
- // ppcoin: coin stake tx must meet target protocol
- if (IsProofOfStake() && !vtx[1].CheckProofOfStake(txdb, nBits))
- return error("ConnectBlock() : Block %s unable to meet hash target for coinstake", GetHash().ToString().c_str());
-
//// issue here: it doesn't know the version
unsigned int nTxPos = pindex->nBlockPos + ::GetSerializeSize(CBlock(), SER_DISK) - (2 * GetSizeOfCompactSize(0)) + GetSizeOfCompactSize(vtx.size());
// ppcoin: fees are not collected by miners as in bitcoin
// ppcoin: fees are destroyed to compensate the entire network
- if (vtx[0].GetValueOut() > GetProofOfWorkReward(nBits))
+ if (IsProofOfWork() && vtx[0].GetValueOut() > GetProofOfWorkReward(nBits))
return false;
if (fDebug && GetBoolArg("-printcreation"))
printf("ConnectBlock() : destroy=%s nFees=%"PRI64d"\n", FormatMoney(nFees).c_str(), nFees);
// 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.
// quantities so as to generate blocks faster, degrading the system back into
// a proof-of-work situation.
//
-bool CTransaction::CheckProofOfStake(CTxDB& txdb, unsigned int nBits) const
+bool CTransaction::CheckProofOfStake(unsigned int nBits) const
{
CBigNum bnTargetPerCoinDay;
bnTargetPerCoinDay.SetCompact(nBits);
if (!IsCoinStake())
return true;
- BOOST_FOREACH(const CTxIn& txin, vin)
- {
- // First try finding the previous transaction in database
- CTransaction txPrev;
- CTxIndex txindex;
- if (!txPrev.ReadFromDisk(txdb, txin.prevout, txindex))
- continue; // previous transaction not in main chain
- if (nTime < txPrev.nTime)
- return false; // Transaction timestamp violation
+ // Input 0 must match the stake hash target per coin age (nBits)
+ const CTxIn& txin = vin[0];
- // Read block header
- CBlock block;
- if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
- return false; // unable to read block of previous transaction
- if (block.GetBlockTime() + AUTO_CHECKPOINT_TRUST_SPAN > nTime)
- continue; // only count coins from at least one week ago
+ // First try finding the previous transaction in database
+ CTxDB txdb("r");
+ CTransaction txPrev;
+ CTxIndex txindex;
+ if (!txPrev.ReadFromDisk(txdb, txin.prevout, txindex))
+ return false; // previous transaction not in main chain
+ txdb.Close();
+ if (nTime < txPrev.nTime)
+ return false; // Transaction timestamp violation
- int64 nValueIn = txPrev.vout[txin.prevout.n].nValue;
- CBigNum bnCoinDay = CBigNum(nValueIn) * (nTime-txPrev.nTime) / COIN / (24 * 60 * 60);
- // Calculate hash
- CDataStream ss(SER_GETHASH, VERSION);
- ss << nBits << block.nTime << (txindex.pos.nTxPos - txindex.pos.nBlockPos) << txPrev.nTime << txin.prevout.n << nTime;
- if (CBigNum(Hash(ss.begin(), ss.end())) <= bnCoinDay * bnTargetPerCoinDay)
- return true;
- }
+ // Verify signature
+ if (!VerifySignature(txPrev, *this, 0))
+ return DoS(100, error("CheckProofOfStake() : VerifySignature failed on coinstake %s", GetHash().ToString().c_str()));
- return false;
+ // Read block header
+ CBlock block;
+ if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
+ return false; // unable to read block of previous transaction
+ if (block.GetBlockTime() + AUTO_CHECKPOINT_TRUST_SPAN > nTime)
+ return false; // only count coins from at least one week ago
+
+ int64 nValueIn = txPrev.vout[txin.prevout.n].nValue;
+ CBigNum bnCoinDay = CBigNum(nValueIn) * (nTime-txPrev.nTime) / COIN / (24 * 60 * 60);
+ // Calculate hash
+ CDataStream ss(SER_GETHASH, VERSION);
+ ss << nBits << block.nTime << (txindex.pos.nTxPos - txindex.pos.nBlockPos) << txPrev.nTime << txin.prevout.n << nTime;
+ if (CBigNum(Hash(ss.begin(), ss.end())) <= bnCoinDay * bnTargetPerCoinDay)
+ return true;
+ else
+ return DoS(100, error("CheckProofOfStake() : check target failed on coinstake %s", GetHash().ToString().c_str()));
}
// ppcoin: total coin age spent in transaction, in the unit of coin-days.
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(make_pair(pindexNew->prevoutStake, pindexNew->nStakeTime));
pindexNew->phashBlock = &((*mi).first);
map<uint256, CBlockIndex*>::iterator miPrev = mapBlockIndex.find(hashPrevBlock);
if (vtx[i].IsCoinStake())
return DoS(100, error("CheckBlock() : coinstake in wrong position"));
+ // ppcoin: coinbase output should be empty if proof-of-stake block
+ if (IsProofOfStake() && !vtx[0].vout[0].IsEmpty())
+ return error("CheckBlock() : coinbase output not empty for proof-of-stake block");
+
// Check coinbase timestamp
if (GetBlockTime() > (int64)vtx[0].nTime + nMaxClockDrift)
return DoS(50, error("CheckBlock() : coinbase timestamp is too early"));
+ // Check coinstake timestamp
+ if (IsProofOfStake() && GetBlockTime() > (int64)vtx[1].nTime + nMaxClockDrift)
+ return DoS(50, error("CheckBlock() : coinstake timestamp is too early"));
+
// Check transactions
BOOST_FOREACH(const CTransaction& tx, vtx)
{
if (hashMerkleRoot != BuildMerkleTree())
return DoS(100, error("CheckBlock() : hashMerkleRoot mismatch"));
- // Coin base vout[0] scriptPubKey must be the same as coin stake vout[1]
- // scriptPubKey
- if (vtx.size() > 1 && vtx[1].IsCoinStake() &&
- vtx[0].vout[0].scriptPubKey != vtx[1].vout[1].scriptPubKey)
- return DoS(100, error("CheckBlock() : block key mismatch"));
-
-
- // Check block signature
+ // ppcoin: check block signature
if (!CheckBlockSignature())
return DoS(100, error("CheckBlock() : bad block signature"));
CBlockIndex* pindexPrev = (*mi).second;
int nHeight = pindexPrev->nHeight+1;
- // ppcoin: check for coinstake duplicate
- if (IsProofOfStake())
- { // check if coinstake is already connected; that would imply the owner
- // of the coinstake sent multiple blocks with the same coinstake
- CTxIndex txindex;
- if (CTxDB("r").ReadTxIndex(vtx[1].GetHash(), txindex))
- return error("AcceptBlock() : block %s has duplicate coinstake %s", hash.ToString().c_str(), vtx[1].GetHash().ToString().c_str());
- }
-
// Check proof-of-work or proof-of-stake
if (nBits != GetNextTargetRequired(pindexPrev, IsProofOfStake()))
return DoS(100, error("AcceptBlock() : incorrect proof-of-work/proof-of-stake"));
+ // ppcoin: coinstake tx must meet target protocol
+ if (IsProofOfStake() && !vtx[1].CheckProofOfStake(nBits))
+ return error("AcceptBlock() : Block %s unable to meet hash target for coinstake", GetHash().ToString().c_str());
+
// Check timestamp against prev
if (GetBlockTime() <= pindexPrev->GetMedianTimePast() || GetBlockTime() + nMaxClockDrift < pindexPrev->GetBlockTime())
return error("AcceptBlock() : block's timestamp is too early");
if (nBestHeight > (pnode->nStartingHeight != -1 ? pnode->nStartingHeight - 2000 : 140700))
pnode->PushInventory(CInv(MSG_BLOCK, hash));
+ // ppcoin: check pending sync-checkpoint
+ Checkpoints::AcceptPendingSyncCheckpoint(hash);
+
return true;
}
if (mapOrphanBlocks.count(hash))
return error("ProcessBlock() : already have block (orphan) %s", hash.ToString().substr(0,20).c_str());
+ // ppcoin: check proof-of-stake
+ // Limited duplicity on stake: prevents block flood attack
+ // Duplicate stake allowed only when there is orphan child block
+ if (pblock->IsProofOfStake() && setStakeSeen.count(pblock->GetProofOfStake()) && !mapOrphanBlocksByPrev.count(hash))
+ return error("ProcessBlock() : duplicate proof-of-stake (%s, %d) for block %s", pblock->GetProofOfStake().first.ToString().c_str(), pblock->GetProofOfStake().second, hash.ToString().c_str());
+
// Preliminary checks
if (!pblock->CheckBlock())
return error("ProcessBlock() : CheckBlock FAILED");
{
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())
+ {
+ // Limited duplicity on stake: prevents block flood attack
+ // Duplicate stake allowed only when there is orphan child block
+ if (setStakeSeenOrphan.count(pblock2->GetProofOfStake()) && !mapOrphanBlocksByPrev.count(hash))
+ return error("ProcessBlock() : duplicate proof-of-stake (%s, %d) for orphan block %s", pblock2->GetProofOfStake().first.ToString().c_str(), pblock2->GetProofOfStake().second, hash.ToString().c_str());
+ else
+ setStakeSeenOrphan.insert(pblock2->GetProofOfStake());
+ }
mapOrphanBlocks.insert(make_pair(hash, pblock2));
mapOrphanBlocksByPrev.insert(make_pair(pblock2->hashPrevBlock, pblock2));
if (pblockOrphan->AcceptBlock())
vWorkQueue.push_back(pblockOrphan->GetHash());
mapOrphanBlocks.erase(pblockOrphan->GetHash());
+ setStakeSeenOrphan.erase(pblockOrphan->GetProofOfStake());
delete pblockOrphan;
}
mapOrphanBlocksByPrev.erase(hashPrev);
return error("LoadBlockIndex() : writing genesis block to disk failed");
if (!block.AddToBlockIndex(nFile, nBlockPos))
return error("LoadBlockIndex() : genesis block not accepted");
+
+ // ppcoin: initialize synchronized checkpoint
+ CTxDB txdbc;
+ if (!txdbc.WriteSyncCheckpoint(hashGenesisBlock))
+ return error("LoadBlockIndex() : failed to init sync checkpoint");
+ txdbc.Close();
+ Checkpoints::hashSyncCheckpoint = hashGenesisBlock;
}
return true;
BOOST_FOREACH(PAIRTYPE(const uint256, CAlert)& item, mapAlerts)
item.second.RelayTo(pfrom);
+ // ppcoin: relay sync-checkpoint
+ CRITICAL_BLOCK(Checkpoints::cs_hashSyncCheckpoint)
+ if (!Checkpoints::checkpointMessage.IsNull())
+ Checkpoints::checkpointMessage.RelayTo(pfrom);
+
pfrom->fSuccessfullyConnected = true;
printf("version message: version %d, blocks=%d\n", pfrom->nVersion, pfrom->nStartingHeight);
}
}
+ else if (strCommand == "checkpoint")
+ {
+ CSyncCheckpoint checkpoint;
+ vRecv >> checkpoint;
+
+ if (checkpoint.ProcessSyncCheckpoint(pfrom))
+ {
+ // Relay
+ pfrom->hashCheckpointKnown = checkpoint.hashCheckpoint;
+ CRITICAL_BLOCK(cs_vNodes)
+ BOOST_FOREACH(CNode* pnode, vNodes)
+ checkpoint.RelayTo(pnode);
+ }
+ }
else
{
pblock->vtx.push_back(txNew);
// ppcoin: if coinstake available add coinstake tx
- static unsigned int nLastCoinStakeCheckTime = GetAdjustedTime() - nMaxClockDrift; // only initialized at startup
+ static unsigned int nLastCoinStakeCheckTime = GetAdjustedTime() - nMaxClockDrift + 60; // only initialized at startup
CBlockIndex* pindexPrev = pindexBest;
while (nLastCoinStakeCheckTime < GetAdjustedTime())
{
CTransaction txCoinStake;
CRITICAL_BLOCK(cs)
{
- nLastCoinStakeCheckTime++;
+ // mining may have been suspended for a while so
+ // need to take max to satisfy the timestamp protocol
+ nLastCoinStakeCheckTime = max(++nLastCoinStakeCheckTime, (unsigned int) (GetAdjustedTime() - nMaxClockDrift + 60));
txCoinStake.nTime = nLastCoinStakeCheckTime;
}
- if (pwallet->CreateCoinStake(txNew.vout[0].scriptPubKey, pblock->nBits, txCoinStake))
+ if (pwallet->CreateCoinStake(pblock->nBits, txCoinStake))
{
pblock->vtx.push_back(txCoinStake);
+ pblock->vtx[0].vout[0].SetEmpty();
break;
}
}
}
}
}
- pblock->vtx[0].vout[0].nValue = GetProofOfWorkReward(pblock->nBits);
+ if (pblock->IsProofOfWork())
+ pblock->vtx[0].vout[0].nValue = GetProofOfWorkReward(pblock->nBits);
// Fill in header
pblock->hashPrevBlock = pindexPrev->GetBlockHash();
git://git.novaco.in / novacoin.git / blobdiff