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;
}
// make sure all wallets know about the given transaction, in the given block
-void static SyncWithWallets(const CTransaction& tx, const CBlock* pblock = NULL, bool fUpdate = false)
+void static SyncWithWallets(const CTransaction& tx, const CBlock* pblock = NULL, bool fUpdate = false, bool fConnect = true)
{
+ if (!fConnect)
+ {
+ // ppcoin: wallets need to refund inputs when disconnecting coinstake
+ if (tx.IsCoinStake())
+ BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
+ if (pwallet->IsFromMe(tx))
+ pwallet->DisableTransaction(tx);
+ return;
+ }
+
BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
pwallet->AddToWalletIfInvolvingMe(tx, pblock, fUpdate);
}
// 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
return bnResult.GetCompact();
}
-unsigned int static GetNextWorkRequired(const CBlockIndex* pindexLast)
+// ppcoin: find last block index up to pindex
+const CBlockIndex* GetLastBlockIndex(const CBlockIndex* pindex, bool fProofOfStake)
+{
+ while (pindex && (pindex->IsProofOfStake() != fProofOfStake))
+ pindex = pindex->pprev;
+ return pindex;
+}
+
+unsigned int static GetNextTargetRequired(const CBlockIndex* pindexLast, bool fProofOfStake)
{
// Genesis block and first block
if (pindexLast == NULL || pindexLast->pprev == NULL)
return bnProofOfWorkLimit.GetCompact();
- int64 nActualSpacing = pindexLast->GetBlockTime() - pindexLast->pprev->GetBlockTime();
+ const CBlockIndex* pindexPrev = GetLastBlockIndex(pindexLast, fProofOfStake);
+ if (pindexPrev == NULL)
+ return bnProofOfWorkLimit.GetCompact();
+ const CBlockIndex* pindexPrevPrev = GetLastBlockIndex(pindexPrev->pprev, fProofOfStake);
+ if (pindexPrevPrev == NULL)
+ return bnProofOfWorkLimit.GetCompact();
+ int64 nActualSpacing = pindexPrev->GetBlockTime() - pindexPrevPrev->GetBlockTime();
// 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);
return error("DisconnectBlock() : WriteBlockIndex failed");
}
+ // ppcoin: clean up wallet after disconnecting coinstake
+ BOOST_FOREACH(CTransaction& tx, vtx)
+ SyncWithWallets(tx, this, false, false);
+
return true;
}
return false;
//// issue here: it doesn't know the version
- unsigned int nTxPos = pindex->nBlockPos + ::GetSerializeSize(CBlock(), SER_DISK) - 1 + GetSizeOfCompactSize(vtx.size());
+ unsigned int nTxPos = pindex->nBlockPos + ::GetSerializeSize(CBlock(), SER_DISK) - (2 * GetSizeOfCompactSize(0)) + GetSizeOfCompactSize(vtx.size());
map<uint256, CTxIndex> mapQueuedChanges;
int64 nFees = 0;
// 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:
+// 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.
+// The reason this hash is chosen is the following:
+// nBits: encodes all past block timestamps, making computing hash in advance
+// more difficult
+// txPrev.block.nTime: prevent nodes from guessing a good timestamp to
+// generate transaction for future advantage
+// txPrev.offset: offset of txPrev inside block, to reduce the chance of
+// nodes generating coinstake at the same time
+// txPrev.nTime: reduce the chance of nodes generating coinstake at the same
+// time
+// txPrev.vout.n: output number of txPrev, to reduce the chance of nodes
+// generating coinstake at the same time
+// block/tx hash should not be used here as they can be generated in vast
+// quantities so as to generate blocks faster, degrading the system back into
+// a proof-of-work situation.
+//
+bool CTransaction::CheckProofOfStake(unsigned int nBits) const
+{
+ CBigNum bnTargetPerCoinDay;
+ bnTargetPerCoinDay.SetCompact(nBits);
+
+ if (!IsCoinStake())
+ return true;
+
+ // Input 0 must match the stake hash target per coin age (nBits)
+ const CTxIn& txin = vin[0];
+
+ // 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
+
+ // Verify signature
+ if (!VerifySignature(txPrev, *this, 0))
+ return DoS(100, error("CheckProofOfStake() : VerifySignature failed on coinstake %s", GetHash().ToString().c_str()));
+
+ // 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.
// Only those coins last spent at least a week ago count. As those
// transactions not in main chain are not currently indexed so we
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);
return DoS(100, error("CheckBlock() : size limits failed"));
// Check proof of work matches claimed amount
- if (!CheckProofOfWork(GetHash(), nBits))
+ if (IsProofOfWork() && !CheckProofOfWork(GetHash(), nBits))
return DoS(50, error("CheckBlock() : proof of work failed"));
// Check timestamp
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"));
+ // ppcoin: check block signature
+ if (!CheckBlockSignature())
+ return DoS(100, error("CheckBlock() : bad block signature"));
+
return true;
}
CBlockIndex* pindexPrev = (*mi).second;
int nHeight = pindexPrev->nHeight+1;
- // Check proof of work
- if (nBits != GetNextWorkRequired(pindexPrev))
- return DoS(100, error("AcceptBlock() : incorrect proof of work"));
+ // 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())
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");
bnNewBlock.SetCompact(pblock->nBits);
CBigNum bnRequired;
bnRequired.SetCompact(ComputeMinWork(pcheckpoint->nBits, deltaTime));
- if (bnNewBlock > bnRequired)
+ if (pblock->IsProofOfWork() && bnNewBlock > bnRequired)
{
pfrom->Misbehaving(100);
return error("ProcessBlock() : block with too little proof-of-work");
{
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);
assert(block.hashMerkleRoot == uint256("0xc7311b56de266580cca65be108ae53d7100b5c3b17da8b1106044103abd7a521"));
block.print();
assert(block.GetHash() == hashGenesisBlock);
+ assert(block.CheckBlock());
// Start new block file
unsigned int nFile;
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;
// print item
CBlock block;
block.ReadFromDisk(pindex);
- printf("%d (%u,%u) %s %s tx %d",
+ printf("%d (%u,%u) %s %08lx %s tx %d",
pindex->nHeight,
pindex->nFile,
pindex->nBlockPos,
block.GetHash().ToString().substr(0,20).c_str(),
+ block.nBits,
DateTimeStrFormat("%x %H:%M:%S", block.GetBlockTime()).c_str(),
block.vtx.size());
return true;
}
+ // ppcoin: record my external IP reported by peer
+ if (addrFrom.IsRoutable() && addrMe.IsRoutable())
+ addrSeenByPeer = addrMe;
+
// Be shy and don't send version until we hear
if (pfrom->fInbound)
pfrom->PushVersion();
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
{
CBlock* CreateNewBlock(CWallet* pwallet)
{
- CBlockIndex* pindexPrev = pindexBest;
CReserveKey reservekey(pwallet);
// Create new block
pblock->vtx.push_back(txNew);
// ppcoin: if coinstake available add coinstake tx
- CTransaction txCoinStake;
- if (pwallet->CreateCoinStake(txNew.vout[0].scriptPubKey, txCoinStake))
- pblock->vtx.push_back(txCoinStake);
+ static unsigned int nLastCoinStakeCheckTime = GetAdjustedTime() - nMaxClockDrift + 60; // only initialized at startup
+ CBlockIndex* pindexPrev = pindexBest;
+ while (nLastCoinStakeCheckTime < GetAdjustedTime())
+ {
+ pindexPrev = pindexBest; // get best block again to avoid getting stale
+ pblock->nBits = GetNextTargetRequired(pindexPrev, true);
+ static CCriticalSection cs;
+ CTransaction txCoinStake;
+ CRITICAL_BLOCK(cs)
+ {
+ // 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(pblock->nBits, txCoinStake))
+ {
+ pblock->vtx.push_back(txCoinStake);
+ pblock->vtx[0].vout[0].SetEmpty();
+ break;
+ }
+ }
+
+ pblock->nBits = GetNextTargetRequired(pindexPrev, pblock->IsProofOfStake());
// Collect memory pool transactions into the block
int64 nFees = 0;
}
}
}
- pblock->nBits = GetNextWorkRequired(pindexPrev);
- 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();
uint256 hash = pblock->GetHash();
uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
- if (hash > hashTarget)
- return false;
+ if (hash > hashTarget && pblock->IsProofOfWork())
+ return error("BitcoinMiner : proof-of-work not meeting target");
//// debug print
printf("BitcoinMiner:\n");
- printf("proof-of-work found \n hash: %s \ntarget: %s\n", hash.GetHex().c_str(), hashTarget.GetHex().c_str());
+ printf("new block found \n hash: %s \ntarget: %s\n", hash.GetHex().c_str(), hashTarget.GetHex().c_str());
pblock->print();
printf("%s ", DateTimeStrFormat("%x %H:%M", GetTime()).c_str());
printf("generated %s\n", FormatMoney(pblock->vtx[0].vout[0].nValue).c_str());
auto_ptr<CBlock> pblock(CreateNewBlock(pwallet));
if (!pblock.get())
return;
+
IncrementExtraNonce(pblock.get(), pindexPrev, nExtraNonce);
+ // ppcoin: if proof-of-stake block found then process block
+ if (pblock->IsProofOfStake())
+ {
+ // should be able to sign block - assert here for now
+ assert(pblock->SignBlock(*pwalletMain));
+ printf("BitcoinMiner : proof-of-stake block found %s\n", pblock->GetHash().ToString().c_str());
+ SetThreadPriority(THREAD_PRIORITY_NORMAL);
+ CheckWork(pblock.get(), *pwalletMain, reservekey);
+ SetThreadPriority(THREAD_PRIORITY_LOWEST);
+ continue;
+ }
+
printf("Running BitcoinMiner with %d transactions in block\n", pblock->vtx.size());
// Found a solution
pblock->nNonce = ByteReverse(nNonceFound);
assert(hash == pblock->GetHash());
+ // should be able to sign block - assert here for now
+ assert(pblock->SignBlock(*pwalletMain));
SetThreadPriority(THREAD_PRIORITY_NORMAL);
CheckWork(pblock.get(), *pwalletMain, reservekey);
git://git.novaco.in / novacoin.git / blobdiff