You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

829 lines
36 KiB

// modify time.1462237906 modifier.baed58b98a00e41d
#include "iguana777.h"
#define CENT (SATOSHIDEN / 100)
#define COIN_YEAR_REWARD ((int64_t)5 * CENT) // 5% per year
#define NCOINBASEMATURITY 100
#define STAKE_TIMESTAMP_MASK 15
#define NTARGETSPACING 60 // BitcoinDark - 1 minute
#define NTARGETTIMESPAN (60 * NTARGETSPACING) // BitcoinDark - every 1 hour
#define NINTERVAL_MSPACING (((NTARGETTIMESPAN / NTARGETSPACING) - 1) * NTARGETSPACING)
#define NINTERVAL_PSPACING (((NTARGETTIMESPAN / NTARGETSPACING) + 1) * NTARGETSPACING)
#define NSTAKESPLITAGE (1 * 24 * NTARGETTIMESPAN)
#define NSTAKE_MINAGE (8 * NTARGETTIMESPAN) // BitcoinDark - 8 hours
#define NSTAKEMAXAGE ((int64_t)-1)
#define NMAXSTAKESEARCHINTERVAL 60
#define NSTAKECOMBINETHRESHOLD (1000 * COIN)
// ratio of group interval length between the last group and the first group
#define MODIFIER_INTERVAL_RATIO 3
#define NMODIFIERINTERVAL (10 * NTARGETSPACING) // BitcoinDark - time to elapse before new modifier is
// miner's coin stake reward based on coin age spent (coin-days)
int64_t iguana_POSreward(int64_t nCoinAge, int64_t nFees)
{
int64_t nSubsidy = (nCoinAge * COIN_YEAR_REWARD * 33) / (365 * 33 + 8);
return(nSubsidy + nFees);
}
// maximum nBits value could possible be required nTime after
uint32_t iguana_maxbits(bits256 targetval,uint32_t nBits,int64_t nTime)
{
bits256 bitsval;
bitsval = bits256_from_compact(nBits);
bitsval = bits256_lshift(bitsval);
while ( nTime > 0 && bits256_cmp(bitsval,targetval) < 0 )
{
bitsval = bits256_rshift(bitsval); // Maximum 200% adjustment per day...
nTime -= 24 * 60 * 60;
}
if ( bits256_cmp(bitsval,targetval) > 0 )
bitsval = targetval;
return(bits256_to_compact(bitsval));
}
bits256 iguana_targetval(struct iguana_info *coin,int32_t height,int32_t PoSflag)
{
int32_t i; bits256 targetval;
if ( PoSflag == 0 )
return(coin->chain->PoWtarget);
else
{
targetval = coin->chain->PoStargets[0];
for (i=0; i<coin->chain->numPoStargets; i++)
{
if ( height < coin->chain->PoSheights[i] )
break;
targetval = coin->chain->PoStargets[i];
}
}
return(targetval);
}
// minimum amount of stake that could possibly be required nTime after
// minimum proof-of-stake required was nBase
uint32_t iguana_minstake(struct iguana_info *coin,int32_t height,uint32_t nBits,int64_t nTime,uint32_t nBlockTime)
{
return(iguana_maxbits(iguana_targetval(coin,height,1),nBits,nTime));
}
uint32_t iguana_targetbits(struct iguana_info *coin,struct iguana_block *hwmchain,struct iguana_block *prev,struct iguana_block *prev2,int32_t PoSflag)
{
bits256 mpz_muldivcmp(bits256 oldval,int32_t mulval,int32_t divval,bits256 cmpval);
bits256 targetval; int32_t gap;
if ( hwmchain->height <= 2 )
return(hwmchain->RO.bits);
targetval = iguana_targetval(coin,hwmchain->height,PoSflag);
if ( prev != 0 )
{
if ( prev2 != 0 )
{
//if ( prev->RO.timestamp != 0 && prev2->RO.timestamp != 0 ) skip check for compatiblity
{
if ( (gap= prev->RO.timestamp - prev2->RO.timestamp) < 0 )
gap = NTARGETSPACING;
// ppcoin: target change every block, retarget with exponential moving toward target spacing
//printf("MSPACING.%d gap.%d\n",NINTERVAL_MSPACING,gap);
targetval = mpz_muldivcmp(bits256_from_compact(prev->RO.bits),NINTERVAL_MSPACING + (gap << 1),NINTERVAL_PSPACING,targetval);
}
}
}
return(bits256_to_compact(targetval));
}
#ifdef reference
CBigNum bnProofOfStakeLimit(~uint256(0) >> 20);
CBigNum bnProofOfStakeLimitV2(~uint256(0) >> 48);
enum
{
BLOCK_PROOF_OF_STAKE = (1 << 0), // is proof-of-stake block
BLOCK_STAKE_ENTROPY = (1 << 1), // entropy bit for stake modifier
BLOCK_STAKE_MODIFIER = (1 << 2), // regenerated stake modifier
};
uint64_t nStakeModifier; // hash modifier for proof-of-stake
uint32_t nStakeModifierChecksum; // checksum of index; in-memory only
uint256 CBlockIndex::GetBlockTrust() const
{
CBigNum bnTarget;
bnTarget.SetCompact(nBits);
if (bnTarget <= 0)
return 0;
return ((CBigNum(1)<<256) / (bnTarget+1)).getuint256();
}
uint32_t GetStakeEntropyBit() const
{
return ((nFlags & BLOCK_STAKE_ENTROPY) >> 1);
}
bool SetStakeEntropyBit(uint32_t nEntropyBit)
{
if (nEntropyBit > 1)
return false;
nFlags |= (nEntropyBit? BLOCK_STAKE_ENTROPY : 0);
return true;
}
bool GeneratedStakeModifier() const
{
return (nFlags & BLOCK_STAKE_MODIFIER);
}
void SetStakeModifier(uint64_t nModifier, bool fGeneratedStakeModifier)
{
nStakeModifier = nModifier;
if (fGeneratedStakeModifier)
nFlags |= BLOCK_STAKE_MODIFIER;
}
// ppcoin: total coin age spent in transaction, in the unit of coin-days.
// Only those coins meeting minimum age requirement counts. As those
// transactions not in main chain are not currently indexed so we
// might not find out about their coin age. Older transactions are
// guaranteed to be in main chain by sync-checkpoint. This rule is
// introduced to help nodes establish a consistent view of the coin
// age (trust score) of competing branches.
bool CTransaction::GetCoinAge(CTxDB& txdb, uint64_t& nCoinAge) const
{
CBigNum bnCentSecond = 0; // coin age in the unit of cent-seconds
nCoinAge = 0;
if (IsCoinBase())
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
// 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() + NSTAKE_MINAGE > nTime)
continue; // only count coins meeting min age requirement
int64_t nValueIn = txPrev.vout[txin.prevout.n].nValue;
bnCentSecond += CBigNum(nValueIn) * (nTime-txPrev.nTime) / CENT;
if (fDebug && GetBoolArg("-printcoinage"))
printf("coin age nValueIn=%"PRId64" nTimeDiff=%d bnCentSecond=%s\n", nValueIn, nTime - txPrev.nTime, bnCentSecond.ToString().c_str());
}
CBigNum bnCoinDay = bnCentSecond * CENT / COIN / (24 * 60 * 60);
if (fDebug && GetBoolArg("-printcoinage"))
printf("coin age bnCoinDay=%s\n", bnCoinDay.ToString().c_str());
nCoinAge = bnCoinDay.getuint64();
return true;
}
// ppcoin: total coin age spent in block, in the unit of coin-days.
bool CBlock::GetCoinAge(uint64_t& nCoinAge) const
{
nCoinAge = 0;
CTxDB txdb("r");
BOOST_FOREACH(const CTransaction& tx, vtx)
{
uint64_t nTxCoinAge;
if (tx.GetCoinAge(txdb, nTxCoinAge))
nCoinAge += nTxCoinAge;
else
return false;
}
if (nCoinAge == 0) // block coin age minimum 1 coin-day
nCoinAge = 1;
if (fDebug && GetBoolArg("-printcoinage"))
printf("block coin age total nCoinDays=%"PRId64"\n", nCoinAge);
return true;
}
// Get time weight
int64_t GetWeight(int64_t nIntervalBeginning,int64_t nIntervalEnd)
{
// Kernel hash weight starts from 0 at the min age
// this change increases active coins participating the hash and helps
// to secure the network when proof-of-stake difficulty is low
return min(nIntervalEnd - nIntervalBeginning - NSTAKE_MINAGE,NSTAKEMAXAGE);
}
// Get the last stake modifier and its generation time from a given block
static bool GetLastStakeModifier(const CBlockIndex* pindex, uint64_t& nStakeModifier, int64_t& nModifierTime)
{
if (!pindex)
return error("GetLastStakeModifier: null pindex");
while (pindex && pindex->pprev && !pindex->GeneratedStakeModifier())
pindex = pindex->pprev;
if (!pindex->GeneratedStakeModifier())
return error("GetLastStakeModifier: no generation at genesis block");
nStakeModifier = pindex->nStakeModifier;
nModifierTime = pindex->GetBlockTime();
return true;
}
// Get selection interval section (in seconds)
static int64_t GetStakeModifierSelectionIntervalSection(int32_t nSection)
{
assert (nSection >= 0 && nSection < 64);
return (NMODIFIERINTERVAL * 63 / (63 + ((63 - nSection) * (MODIFIER_INTERVAL_RATIO - 1))));
}
// Get stake modifier selection interval (in seconds)
static int64_t GetStakeModifierSelectionInterval()
{
int64_t nSelectionInterval = 0;
for (int32_t nSection=0; nSection<64; nSection++)
nSelectionInterval += GetStakeModifierSelectionIntervalSection(nSection);
return nSelectionInterval;
}
// select a block from the candidate blocks in vSortedByTimestamp, excluding
// already selected blocks in vSelectedBlocks, and with timestamp up to nSelectionIntervalStop.
static bool SelectBlockFromCandidates(vector<pair<int64_t, uint256> >& vSortedByTimestamp, map<uint256, const CBlockIndex*>& mapSelectedBlocks,int64_t nSelectionIntervalStop, uint64_t nStakeModifierPrev, const CBlockIndex **pindexSelected)
{
bool fSelected = false; uint256 hashBest = 0;
*pindexSelected = (const CBlockIndex*) 0;
BOOST_FOREACH(const PAIRTYPE(int64_t, uint256)&item, vSortedByTimestamp)
{
if (!mapBlockIndex.count(item.second))
return error("SelectBlockFromCandidates: failed to find block index for candidate block %s", item.second.ToString().c_str());
const CBlockIndex *pindex = mapBlockIndex[item.second];
if ( fSelected && pindex->GetBlockTime() > nSelectionIntervalStop )
break;
if (mapSelectedBlocks.count(pindex->GetBlockHash()) > 0)
continue;
// compute the selection hash by hashing its proof-hash and the previous proof-of-stake modifier
CDataStream ss(SER_GETHASH, 0);
ss << pindex->hashProof << nStakeModifierPrev;
uint256 hashSelection = Hash(ss.begin(), ss.end());
// the selection hash is divided by 2**32 so that proof-of-stake block is always favored over proof-of-work block. this is to preserve the energy efficiency property
if ( pindex->IsProofOfStake() )
hashSelection >>= 32;
if ( fSelected && hashSelection < hashBest )
{
hashBest = hashSelection;
*pindexSelected = (const CBlockIndex*) pindex;
}
else if (!fSelected)
{
fSelected = true;
hashBest = hashSelection;
*pindexSelected = (const CBlockIndex*) pindex;
}
}
if (fDebug && GetBoolArg("-printstakemodifier"))
printf("SelectBlockFromCandidates: selection hash=%s\n", hashBest.ToString().c_str());
return fSelected;
}
// Stake Modifier (hash modifier of proof-of-stake):
// The purpose of stake modifier is to prevent a txout (coin) owner from
// computing future proof-of-stake generated by this txout at the time
// of transaction confirmation. To meet kernel protocol, the txout
// must hash with a future stake modifier to generate the proof.
// Stake modifier consists of bits each of which is contributed from a
// selected block of a given block group in the past.
// The selection of a block is based on a hash of the block's proof-hash and
// the previous stake modifier.
// Stake modifier is recomputed at a fixed time interval instead of every
// block. This is to make it difficult for an attacker to gain control of
// additional bits in the stake modifier, even after generating a chain of
// blocks.
bool ComputeNextStakeModifier(const CBlockIndex* pindexPrev, uint64_t& nStakeModifier, bool& fGeneratedStakeModifier)
{
nStakeModifier = 0;
fGeneratedStakeModifier = false;
if (!pindexPrev)
{
fGeneratedStakeModifier = true;
return true; // genesis block's modifier is 0
}
// First find current stake modifier and its generation block time
// if it's not old enough, return the same stake modifier
int64_t nModifierTime = 0;
if (!GetLastStakeModifier(pindexPrev, nStakeModifier, nModifierTime))
return error("ComputeNextStakeModifier: unable to get last modifier");
if (fDebug)
{
printf("ComputeNextStakeModifier: prev modifier=0x%016"PRIx64" time=%s\n", nStakeModifier, DateTimeStrFormat(nModifierTime).c_str());
}
if (nModifierTime / NMODIFIERINTERVAL >= pindexPrev->GetBlockTime() / NMODIFIERINTERVAL)
return true;
// Sort candidate blocks by timestamp
vector<pair<int64_t, uint256> > vSortedByTimestamp;
vSortedByTimestamp.reserve(64 * (NMODIFIERINTERVAL / NTARGETSPACING));
int64_t nSelectionInterval = GetStakeModifierSelectionInterval();
int64_t nSelectionIntervalStart = (pindexPrev->GetBlockTime() / NMODIFIERINTERVAL) * NMODIFIERINTERVAL - nSelectionInterval;
const CBlockIndex* pindex = pindexPrev;
while (pindex && pindex->GetBlockTime() >= nSelectionIntervalStart)
{
vSortedByTimestamp.push_back(make_pair(pindex->GetBlockTime(), pindex->GetBlockHash()));
pindex = pindex->pprev;
}
int32_t nHeightFirstCandidate = pindex ? (pindex->nHeight + 1) : 0;
reverse(vSortedByTimestamp.begin(), vSortedByTimestamp.end());
sort(vSortedByTimestamp.begin(), vSortedByTimestamp.end());
// Select 64 blocks from candidate blocks to generate stake modifier
uint64_t nStakeModifierNew = 0;
int64_t nSelectionIntervalStop = nSelectionIntervalStart;
map<uint256, const CBlockIndex*> mapSelectedBlocks;
for (int32_t nRound=0; nRound<min(64, (int)vSortedByTimestamp.size()); nRound++)
{
// add an interval section to the current selection round
nSelectionIntervalStop += GetStakeModifierSelectionIntervalSection(nRound);
// select a block from the candidates of current round
if (!SelectBlockFromCandidates(vSortedByTimestamp, mapSelectedBlocks, nSelectionIntervalStop, nStakeModifier, &pindex))
return error("ComputeNextStakeModifier: unable to select block at round %d", nRound);
// write the entropy bit of the selected block
nStakeModifierNew |= (((uint64_t)pindex->GetStakeEntropyBit()) << nRound);
// add the selected block from candidates to selected list
mapSelectedBlocks.insert(make_pair(pindex->GetBlockHash(), pindex));
if (fDebug && GetBoolArg("-printstakemodifier"))
printf("ComputeNextStakeModifier: selected round %d stop=%s height=%d bit=%d\n", nRound, DateTimeStrFormat(nSelectionIntervalStop).c_str(), pindex->nHeight, pindex->GetStakeEntropyBit());
}
// Print selection map for visualization of the selected blocks
if (fDebug && GetBoolArg("-printstakemodifier"))
{
string strSelectionMap = "";
// '-' indicates proof-of-work blocks not selected
strSelectionMap.insert(0, pindexPrev->nHeight - nHeightFirstCandidate + 1, '-');
pindex = pindexPrev;
while (pindex && pindex->nHeight >= nHeightFirstCandidate)
{
// '=' indicates proof-of-stake blocks not selected
if (pindex->IsProofOfStake())
strSelectionMap.replace(pindex->nHeight - nHeightFirstCandidate, 1, "=");
pindex = pindex->pprev;
}
BOOST_FOREACH(const PAIRTYPE(uint256, const CBlockIndex*)& item, mapSelectedBlocks)
{
// 'S' indicates selected proof-of-stake blocks
// 'W' indicates selected proof-of-work blocks
strSelectionMap.replace(item.second->nHeight - nHeightFirstCandidate, 1, item.second->IsProofOfStake()? "S" : "W");
}
printf("ComputeNextStakeModifier: selection height [%d, %d] map %s\n", nHeightFirstCandidate, pindexPrev->nHeight, strSelectionMap.c_str());
}
if (fDebug)
{
printf("ComputeNextStakeModifier: new modifier=0x%016"PRIx64" time=%s\n", nStakeModifierNew, DateTimeStrFormat(pindexPrev->GetBlockTime()).c_str());
}
nStakeModifier = nStakeModifierNew;
fGeneratedStakeModifier = true;
return true;
}
// The stake modifier used to hash for a stake kernel is chosen as the stake
// modifier about a selection interval later than the coin generating the kernel
static bool GetKernelStakeModifier(uint256 hashBlockFrom, uint64_t& nStakeModifier, int& nStakeModifierHeight, int64_t& nStakeModifierTime, bool fPrintProofOfStake)
{
nStakeModifier = 0;
if (!mapBlockIndex.count(hashBlockFrom))
return error("GetKernelStakeModifier() : block not indexed");
const CBlockIndex* pindexFrom = mapBlockIndex[hashBlockFrom];
nStakeModifierHeight = pindexFrom->nHeight;
nStakeModifierTime = pindexFrom->GetBlockTime();
int64_t nStakeModifierSelectionInterval = GetStakeModifierSelectionInterval();
const CBlockIndex* pindex = pindexFrom;
// loop to find the stake modifier later by a selection interval
while (nStakeModifierTime < pindexFrom->GetBlockTime() + nStakeModifierSelectionInterval)
{
if (!pindex->pnext)
{ // reached best block; may happen if node is behind on block chain
if (fPrintProofOfStake || (pindex->GetBlockTime() + NSTAKE_MINAGE - nStakeModifierSelectionInterval > GetAdjustedTime()))
return error("GetKernelStakeModifier() : reached best block %s at height %d from block %s",pindex->GetBlockHash().ToString().c_str(), pindex->nHeight, hashBlockFrom.ToString().c_str());
else return false;
}
pindex = pindex->pnext;
if (pindex->GeneratedStakeModifier())
{
nStakeModifierHeight = pindex->nHeight;
nStakeModifierTime = pindex->GetBlockTime();
}
}
nStakeModifier = pindex->nStakeModifier;
return true;
}
// ppcoin kernel protocol
// coinstake must meet hash target according to the protocol:
// kernel (input 0) must meet the formula
// hash(nStakeModifier + txPrev.block.nTime + txPrev.offset + txPrev.nTime + txPrev.vout.n + nTime) < bnTarget * nCoinDayWeight
// 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:
// nStakeModifier: scrambles computation to make it very difficult to precompute
// future proof-of-stake at the time of the coin's confirmation
// 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 CheckStakeKernelHashV1(uint32_t nBits, const CBlock& blockFrom,uint32_t nTxPrevOffset, const CTransaction& txPrev, const COutPoint& prevout,uint32_t nTimeTx, uint256& hashProofOfStake, uint256& targetProofOfStake, bool fPrintProofOfStake)
{
if (nTimeTx < txPrev.nTime) // Transaction timestamp violation
return error("CheckStakeKernelHash() : nTime violation");
uint32_t nTimeBlockFrom = blockFrom.GetBlockTime();
if (nTimeBlockFrom + NSTAKE_MINAGE > nTimeTx) // Min age requirement
return error("CheckStakeKernelHash() : min age violation");
CBigNum bnTargetPerCoinDay;
bnTargetPerCoinDay.SetCompact(nBits);
int64_t nValueIn = txPrev.vout[prevout.n].nValue;
uint256 hashBlockFrom = blockFrom.GetHash();
CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)txPrev.nTime, (int64_t)nTimeTx) / COIN / (24 * 60 * 60);
targetProofOfStake = (bnCoinDayWeight * bnTargetPerCoinDay).getuint256();
// Calculate hash
CDataStream ss(SER_GETHASH, 0);
uint64_t nStakeModifier = 0;
int32_t nStakeModifierHeight = 0;
int64_t nStakeModifierTime = 0;
if ( !GetKernelStakeModifier(hashBlockFrom, nStakeModifier, nStakeModifierHeight, nStakeModifierTime, fPrintProofOfStake) )
return false;
ss << nStakeModifier << nTimeBlockFrom << nTxPrevOffset << txPrev.nTime << prevout.n << nTimeTx;
hashProofOfStake = Hash(ss.begin(), ss.end());
if (fPrintProofOfStake)
{
printf("CheckStakeKernelHash() : using modifier 0x%016"PRIx64" at height=%d timestamp=%s for block from height=%d timestamp=%s\n",
nStakeModifier, nStakeModifierHeight,
DateTimeStrFormat(nStakeModifierTime).c_str(),
mapBlockIndex[hashBlockFrom]->nHeight,
DateTimeStrFormat(blockFrom.GetBlockTime()).c_str());
printf("CheckStakeKernelHash() : check modifier=0x%016"PRIx64" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n",
nStakeModifier,
nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx,
hashProofOfStake.ToString().c_str());
}
// Now check if proof-of-stake hash meets target protocol
if (CBigNum(hashProofOfStake) > bnCoinDayWeight * bnTargetPerCoinDay)
return false;
if (fDebug && !fPrintProofOfStake)
{
printf("CheckStakeKernelHash() : using modifier 0x%016"PRIx64" at height=%d timestamp=%s for block from height=%d timestamp=%s\n",
nStakeModifier, nStakeModifierHeight,
DateTimeStrFormat(nStakeModifierTime).c_str(),
mapBlockIndex[hashBlockFrom]->nHeight,
DateTimeStrFormat(blockFrom.GetBlockTime()).c_str());
printf("CheckStakeKernelHash() : pass modifier=0x%016"PRIx64" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n",
nStakeModifier,
nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx,
hashProofOfStake.ToString().c_str());
}
return true;
}
bool CheckStakeKernelHash(CBlockIndex* pindexPrev, uint32_t nBits, const CBlock& blockFrom, uint32_t nTxPrevOffset, const CTransaction& txPrev, const COutPoint& prevout, uint32_t nTimeTx, uint256& hashProofOfStake, uint256& targetProofOfStake, bool fPrintProofOfStake)
{
if (IsPoSV2(pindexPrev->nHeight+1))
return CheckStakeKernelHashV2(pindexPrev, nBits, blockFrom.GetBlockTime(), txPrev, prevout, nTimeTx, hashProofOfStake, targetProofOfStake, fPrintProofOfStake);
else
return CheckStakeKernelHashV1(nBits, blockFrom, nTxPrevOffset, txPrev, prevout, nTimeTx, hashProofOfStake, targetProofOfStake, fPrintProofOfStake);
}
bool CWallet::CreateCoinStake(const CKeyStore& keystore, uint32_t nBits, int64_t nSearchInterval, int64_t nFees, CTransaction& txNew, CKey& key)
{
CBigNum bnTargetPerCoinDay; CBlockIndex *pindexPrev = pindexBest;
bnTargetPerCoinDay.SetCompact(nBits);
txNew.vin.clear();
txNew.vout.clear();
// Mark coin stake transaction
CScript scriptEmpty;
scriptEmpty.clear();
txNew.vout.push_back(CTxOut(0, scriptEmpty));
// Choose coins to use
int64_t nBalance = GetBalance();
if (nBalance <= nReserveBalance)
return false;
vector<const CWalletTx*> vwtxPrev;
set<pair<const CWalletTx*,unsigned int> > setCoins;
int64_t nValueIn = 0;
// Select coins with suitable depth
if (!SelectCoinsSimple(nBalance - nReserveBalance, txNew.nTime, nCoinbaseMaturity + 10, setCoins, nValueIn))
return false;
if (setCoins.empty())
return false;
int64_t nCredit = 0;
CScript scriptPubKeyKernel;
CTxDB txdb("r");
BOOST_FOREACH(PAIRTYPE(const CWalletTx*, unsigned int) pcoin, setCoins)
{
CTxIndex txindex;
{
LOCK2(cs_main, cs_wallet);
if (!txdb.ReadTxIndex(pcoin.first->GetHash(), txindex))
continue;
}
// Read block header
CBlock block;
{
LOCK2(cs_main, cs_wallet);
if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
continue;
}
if (block.GetBlockTime() + NSTAKE_MINAGE > txNew.nTime - NMAXSTAKESEARCHINTERVAL)
continue; // only count coins meeting min age requirement
bool fKernelFound = false;
for (uint32_t n=0; n<min(nSearchInterval,(int64_t)NMAXSTAKESEARCHINTERVAL) && !fKernelFound && !fShutdown && pindexPrev == pindexBest; n++)
{
// Search backward in time from the given txNew timestamp
// Search nSearchInterval seconds back up to NMAXSTAKESEARCHINTERVAL
uint256 hashProofOfStake = 0, targetProofOfStake = 0;
COutPoint prevoutStake = COutPoint(pcoin.first->GetHash(), pcoin.second);
if (CheckStakeKernelHash(pindexPrev, nBits, block, txindex.pos.nTxPos - txindex.pos.nBlockPos, *pcoin.first, prevoutStake, txNew.nTime - n, hashProofOfStake, targetProofOfStake))
{
// Found a kernel
if (fDebug && GetBoolArg("-printcoinstake"))
printf("CreateCoinStake : kernel found\n");
vector<valtype> vSolutions;
txnouttype whichType;
CScript scriptPubKeyOut;
scriptPubKeyKernel = pcoin.first->vout[pcoin.second].scriptPubKey;
if (!Solver(scriptPubKeyKernel, whichType, vSolutions))
{
if (fDebug && GetBoolArg("-printcoinstake"))
printf("CreateCoinStake : failed to parse kernel\n");
break;
}
if (fDebug && GetBoolArg("-printcoinstake"))
printf("CreateCoinStake : parsed kernel type=%d\n", whichType);
if (whichType != TX_PUBKEY && whichType != TX_PUBKEYHASH)
{
if (fDebug && GetBoolArg("-printcoinstake"))
printf("CreateCoinStake : no support for kernel type=%d\n", whichType);
break; // only support pay to public key and pay to address
}
if (whichType == TX_PUBKEYHASH) // pay to address type
{
// convert to pay to public key type
if (!keystore.GetKey(uint160(vSolutions[0]), key))
{
if (fDebug && GetBoolArg("-printcoinstake"))
printf("CreateCoinStake : failed to get key for kernel type=%d\n", whichType);
break; // unable to find corresponding public key
}
scriptPubKeyOut << key.GetPubKey() << OP_CHECKSIG;
}
if (whichType == TX_PUBKEY)
{
valtype& vchPubKey = vSolutions[0];
if (!keystore.GetKey(Hash160(vchPubKey), key))
{
if (fDebug && GetBoolArg("-printcoinstake"))
printf("CreateCoinStake : failed to get key for kernel type=%d\n", whichType);
break; // unable to find corresponding public key
}
if (key.GetPubKey() != vchPubKey)
{
if (fDebug && GetBoolArg("-printcoinstake"))
printf("CreateCoinStake : invalid key for kernel type=%d\n", whichType);
break; // keys mismatch
}
scriptPubKeyOut = scriptPubKeyKernel;
}
txNew.nTime -= n;
txNew.vin.push_back(CTxIn(pcoin.first->GetHash(), pcoin.second));
nCredit += pcoin.first->vout[pcoin.second].nValue;
vwtxPrev.push_back(pcoin.first);
txNew.vout.push_back(CTxOut(0, scriptPubKeyOut));
if (GetWeight(block.GetBlockTime(), (int64_t)txNew.nTime) < nStakeSplitAge)
txNew.vout.push_back(CTxOut(0, scriptPubKeyOut)); //split stake
if (fDebug && GetBoolArg("-printcoinstake"))
printf("CreateCoinStake : added kernel type=%d\n", whichType);
fKernelFound = true;
break;
}
}
if (fKernelFound || fShutdown)
break; // if kernel is found stop searching
}
if (nCredit == 0 || nCredit > nBalance - nReserveBalance)
return false;
BOOST_FOREACH(PAIRTYPE(const CWalletTx*, unsigned int) pcoin, setCoins)
{
// Attempt to add more inputs: Only add coins of the same key/address as kernel
if (txNew.vout.size() == 2 && ((pcoin.first->vout[pcoin.second].scriptPubKey == scriptPubKeyKernel || pcoin.first->vout[pcoin.second].scriptPubKey == txNew.vout[1].scriptPubKey))
&& pcoin.first->GetHash() != txNew.vin[0].prevout.hash)
{
int64_t nTimeWeight = GetWeight((int64_t)pcoin.first->nTime, (int64_t)txNew.nTime);
// Stop adding more inputs if already too many inputs
if (txNew.vin.size() >= 100)
break;
// Stop adding more inputs if value is already pretty significant
if (nCredit >= NSTAKECOMBINETHRESHOLD)
break;
// Stop adding inputs if reached reserve limit
if (nCredit + pcoin.first->vout[pcoin.second].nValue > nBalance - nReserveBalance)
break;
// Do not add additional significant input
if (pcoin.first->vout[pcoin.second].nValue >= NSTAKECOMBINETHRESHOLD)
continue;
// Do not add input that is still too young
if (nTimeWeight < NSTAKE_MINAGE)
continue;
txNew.vin.push_back(CTxIn(pcoin.first->GetHash(), pcoin.second));
nCredit += pcoin.first->vout[pcoin.second].nValue;
vwtxPrev.push_back(pcoin.first);
}
}
// Calculate coin age reward
{
uint64_t nCoinAge;
CTxDB txdb("r");
if (!txNew.GetCoinAge(txdb, nCoinAge))
return error("CreateCoinStake : failed to calculate coin age");
int64_t nReward = iguana_POSreward(nCoinAge, nFees);
if (nReward <= 0)
return false;
nCredit += nReward;
}
// Set output amount
if (txNew.vout.size() == 3)
{
txNew.vout[1].nValue = (nCredit / 2 / CENT) * CENT;
txNew.vout[2].nValue = nCredit - txNew.vout[1].nValue;
} else txNew.vout[1].nValue = nCredit;
// Sign
int32_t nIn = 0;
BOOST_FOREACH(const CWalletTx* pcoin, vwtxPrev)
{
if (!SignSignature(*this, *pcoin, txNew, nIn++))
return error("CreateCoinStake : failed to sign coinstake");
}
// Limit size
uint32_t nBytes = ::GetSerializeSize(txNew, SER_NETWORK, PROTOCOL_VERSION);
if (nBytes >= MAX_BLOCK_SIZE_GEN/5)
return error("CreateCoinStake : exceeded coinstake size limit");
// Successfully generated coinstake
return true;
}
// Check kernel hash target and coinstake signature
bool CheckProofOfStake(CBlockIndex* pindexPrev, const CTransaction& tx, uint32_t nBits, uint256& hashProofOfStake, uint256& targetProofOfStake)
{
if (!tx.IsCoinStake())
return error("CheckProofOfStake() : called on non-coinstake %s", tx.GetHash().ToString().c_str());
// Kernel (input 0) must match the stake hash target per coin age (nBits)
const CTxIn& txin = tx.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 tx.DoS(1, error("CheckProofOfStake() : INFO: read txPrev failed")); // previous transaction not in main chain, may occur during initial download
// Verify signature
if (!VerifySignature(txPrev, tx, 0, 0))
return tx.DoS(100, error("CheckProofOfStake() : VerifySignature failed on coinstake %s", tx.GetHash().ToString().c_str()));
// Read block header
CBlock block;
if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
return fDebug? error("CheckProofOfStake() : read block failed") : false; // unable to read block of previous transaction
if (!CheckStakeKernelHash(pindexPrev, nBits, block, txindex.pos.nTxPos - txindex.pos.nBlockPos, txPrev, txin.prevout, tx.nTime, hashProofOfStake, targetProofOfStake, fDebug))
return tx.DoS(1, error("CheckProofOfStake() : INFO: check kernel failed on coinstake %s, hashProof=%s", tx.GetHash().ToString().c_str(), hashProofOfStake.ToString().c_str())); // may occur during initial download or if behind on block chain sync
return true;
}
// Check whether the coinstake timestamp meets protocol
bool CheckCoinStakeTimestamp(int64_t nTimeBlock, int64_t nTimeTx)
{
// v0.3 protocol
return (nTimeBlock == nTimeTx);
}
// Get stake modifier checksum
uint32_t GetStakeModifierChecksum(const CBlockIndex* pindex)
{
//assert (pindex->pprev || pindex->GetBlockHash() == (!fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet));
// Hash previous checksum with flags, hashProofOfStake and nStakeModifier
CDataStream ss(SER_GETHASH, 0);
if (pindex->pprev)
ss << pindex->pprev->nStakeModifierChecksum;
ss << pindex->nFlags << (pindex->IsProofOfStake() ? pindex->hashProof : 0) << pindex->nStakeModifier;
uint256 hashChecksum = Hash(ss.begin(), ss.end());
hashChecksum >>= (256 - 32);
return hashChecksum.Get64();
}
// Check stake modifier hard checkpoints
bool CheckStakeModifierCheckpoints(int32_t nHeight, uint32_t nStakeModifierChecksum)
{
MapModifierCheckpoints& checkpoints = (fTestNet ? mapStakeModifierCheckpointsTestNet : mapStakeModifierCheckpoints);
if (checkpoints.count(nHeight))
return nStakeModifierChecksum == checkpoints[nHeight];
return true;
}
// novacoin: attempt to generate suitable proof-of-stake
bool CBlock::SignBlock(CWallet& wallet, int64_t nFees)
{
// if we are trying to sign something except proof-of-stake block template
if (!vtx[0].vout[0].IsEmpty())
return false;
// if we are trying to sign a complete proof-of-stake block
if (IsProofOfStake())
return true;
static int64_t nLastCoinStakeSearchTime = GetAdjustedTime(); // startup timestamp
CKey key; CTransaction txCoinStake; int64_t nSearchTime = txCoinStake.nTime; // search to current time
if (nSearchTime > nLastCoinStakeSearchTime)
{
if (wallet.CreateCoinStake(wallet, nBits, nSearchTime-nLastCoinStakeSearchTime, nFees, txCoinStake, key))
{
if (txCoinStake.nTime >= max(pindexBest->GetPastTimeLimit()+1, PastDrift(pindexBest->GetBlockTime())))
{
// make sure coinstake would meet timestamp protocol as it would be the same as the block timestamp
vtx[0].nTime = nTime = txCoinStake.nTime;
nTime = max(pindexBest->GetPastTimeLimit()+1, GetMaxTransactionTime());
nTime = max(GetBlockTime(), PastDrift(pindexBest->GetBlockTime()));
// we have to make sure that we have no future timestamps in our transactions set
for (vector<CTransaction>::iterator it = vtx.begin(); it != vtx.end();)
if (it->nTime > nTime) { it = vtx.erase(it); } else { ++it; }
vtx.insert(vtx.begin() + 1, txCoinStake);
hashMerkleRoot = BuildMerkleTree();
// append a signature to our block
return key.Sign(GetHash(), vchBlockSig);
}
}
nLastCoinStakeSearchInterval = nSearchTime - nLastCoinStakeSearchTime;
nLastCoinStakeSearchTime = nSearchTime;
}
return false;
}
bool CBlock::CheckBlockSignature() const
{
if (IsProofOfWork())
return vchBlockSig.empty();
vector<valtype> vSolutions;
txnouttype whichType;
const CTxOut& txout = vtx[1].vout[1];
if (!Solver(txout.scriptPubKey, whichType, vSolutions))
return false;
if (whichType == TX_PUBKEY)
{
valtype& vchPubKey = vSolutions[0];
CKey key;
if (!key.SetPubKey(vchPubKey))
return false;
if (vchBlockSig.empty())
return false;
return key.Verify(GetHash(), vchBlockSig);
}
return false;
}
#endif