#include <boost/assign/list_of.hpp>
#include "kernel.h"
-#include "db.h"
+#include "txdb.h"
+
+extern unsigned int nStakeMaxAge;
+extern unsigned int nStakeTargetSpacing;
using namespace std;
-extern int nStakeMaxAge;
-extern int nStakeTargetSpacing;
+
+// Protocol switch time for fixed kernel modifier interval
+unsigned int nModifierSwitchTime = 1413763200; // Mon, 20 Oct 2014 00:00:00 GMT
+unsigned int nModifierTestSwitchTime = 1397520000; // Tue, 15 Apr 2014 00:00:00 GMT
+
+// Note: user must upgrade before the protocol switch deadline, otherwise it's required to
+// re-download the blockchain. The timestamp of upgrade is recorded in the blockchain
+// database.
+unsigned int nModifierUpgradeTime = 0;
+
+typedef std::map<int, unsigned int> MapModifierCheckpoints;
// Hard checkpoints of stake modifiers to ensure they are deterministic
static std::map<int, unsigned int> mapStakeModifierCheckpoints =
boost::assign::map_list_of
( 0, 0x0e00670bu )
- ( 6000, 0xb7cbc5d3u )
- ( 9690, 0x97dcdafau )
( 12661, 0x5d84115du )
- ( 19600, 0xdded1b8du )
- ( 21800, 0x0daa1aaau )
- ( 26174, 0xaf9983dcu )
+ (143990, 0x9c592c78u )
+ (149000, 0x48f2bdc4u )
+ (160000, 0x789df0f0u )
;
+// Hard checkpoints of stake modifiers to ensure they are deterministic (testNet)
+static std::map<int, unsigned int> mapStakeModifierCheckpointsTestNet =
+ boost::assign::map_list_of
+ ( 0, 0x0e00670bu )
+ ;
+
+// Pregenerated entropy bits table (from genesis to #9689)
+//
+// Bits are packed into array of 256 bit integers:
+//
+// * array index calculated as nHeight / 256
+// * position of bit is calculated as nHeight & 0xFF.
+//
+const uint256 entropyStore[] = {
+ uint256("0x4555b4dcc1d690ddd9b810c90c66e82b18bf4f43cc887246c418383ec120a5ab"),
+ uint256("0xaa6d1198412fa77608addf6549c9198a22155e8afd7a9ded6179f6b7cfc66b0c"),
+ uint256("0x9442fabfa4116fb14a9769c2eea003845a1f5c3a0260f36b497d68f3a3cd4078"),
+ uint256("0x0e769042a9a98e42388195d699574b822d06515f7053ad884c53d7ee059f05b1"),
+ uint256("0x7005aac20baf70251aebfe3f1b95987d83ef1e3e6963de8fed601d4dd07bf7cf"),
+ uint256("0x58952c5c3de188f2e33c38d3f53d7bf44f9bc545a4289d266696273fa821be66"),
+ uint256("0x50b6c2ed780c08aaec3f7665b1b6004206243e3866456fc910b83b52d07eeb63"),
+ uint256("0x563841eefca85ba3384986c58100408ae3f1ba2ac727e1ac910ce154a06c702f"),
+ uint256("0x79275b03938b3e27a9b01a7f7953c6c487c58355f5d4169accfbb800213ffd13"),
+ uint256("0xd783f2538b3ed18f135af90adc687c5646d93aeaeaabc6667be94f7aa0a2d366"),
+ uint256("0xb441d0c175c40c8e88b09d88ea008af79cbed2d28219427d2e72fda682974db8"),
+ uint256("0x3204c43bd41f2e19628af3b0c9aca3db15bca4c8705d51056e7b17a319c04715"),
+ uint256("0x7e80e6ab7857d8f2f261a0a49c783bd800b365b8c9b85cc0e13f73904b0dcaa9"),
+ uint256("0xefaaee60ed82d2ad145c0e347941fdb131eb8fd289a45eef07121a93f283c5f1"),
+ uint256("0x3efc86e4334da332c1fd4c12513c40cff689f3efdc7f9913230822adacdda4f9"),
+ uint256("0xf0d6b8f38599a017fa35d1fbbf9ef51eca5ebc5b286aadba40c4c3e1d9bace0c"),
+ uint256("0x286a67f27323486036a0a92d35382fc8963c0c00bad331723318b4b9fdb2b56e"),
+ uint256("0xecbfaaa6567c54f08c4d5bd0118a2d7b58740f42cbfc73aa1536c1f5f76de87c"),
+ uint256("0xf9a4de1c5c46520de5aaf10d3796cf0e27ddce98b3398357f5726a949664e308"),
+ uint256("0xd75e6c4dc4be08401e3478d2467d9ab96a62af4f255c04a82c41af0de0a487bb"),
+ uint256("0x1a82c3bc6ad6047294c16571b5e2b7316c97bf8813e7da15798b9820d67e39f2"),
+ uint256("0xb49be0080de564e01829ded7e7971979565a741c5975dc9978dcc020192d396c"),
+ uint256("0x0d8eed113be67663b5a15a0625a9b49792b5ea59c005c4f405914877acab7000"),
+ uint256("0x8f9d46e2bc05a218ffa942965b747056197d393b097085523640cd59e07fe7c7"),
+ uint256("0x7a63ab40bc7f40ac2ebe9ede438d97b45fa6ed6f8419016da8d5f7a670111dda"),
+ uint256("0x63fbcc080448c43d6cf915c958314feff7a95a52ba43a68c05fc281d3a522d25"),
+ uint256("0xf834cf824c326d3ea861ea1e85dc3289265e37045981e28208e7344a7f8081d7"),
+ uint256("0xb4edc22ec98cc49b2f5af5bae3f52f5e6058280f74f2c432c2dd89ae49acceb8"),
+ uint256("0x0fe596037dcf81bf5c64f39755261c404ed088af5c8c31dd7549b6657ee92365"),
+ uint256("0xbbad51a0aeba254b01d18c328de9e932b9b859b61e622c325d64e2211b5e413d"),
+ uint256("0xabf0194cc787be938bc51c7fdf1cae4ec79e65ebab8fa8b8f40541c44ef384b0"),
+ uint256("0x83bc12d6fdbd3e854cb91c4ca7dfba3c38e8714121af88c8a8abdb33e5002438"),
+ uint256("0x71a2513026cabaedcbe55aeb6dc8049e5b763a3f54f10c33dd333624f764b38c"),
+ uint256("0xee6725632ff5c025dff6a18cd059875dcae20f399b03bccba13d9d5fcf6d9d9a"),
+ uint256("0xa168a2741d1e7e50cc74b79f695c25ffd3576e6bd61353c2a20e569fd63b2dac"),
+ uint256("0x6e462d2a87bfde9398b6747f94a8ed6a01e4d96c5b4372df5c910c106c48bd13"),
+ uint256("0x8eeb696181957c4b22434028990f49cb30006827c73860e77e2eecf5c38be99d"),
+ uint256("0x3188aaa65877b166f05cdc48f55b1f77a7d6fb221c395596d990ae5647e9ba96")
+};
+
+// Whether the given block is subject to new modifier protocol
+bool IsFixedModifierInterval(unsigned int nTimeBlock)
+{
+ return (nTimeBlock >= (fTestNet? nModifierTestSwitchTime : nModifierSwitchTime));
+}
+
// Get the last stake modifier and its generation time from a given block
-static bool GetLastStakeModifier(const CBlockIndex* pindex, uint64& nStakeModifier, int64& nModifierTime)
+static bool GetLastStakeModifier(const CBlockIndex* pindex, uint64_t& nStakeModifier, int64_t& nModifierTime)
{
if (!pindex)
return error("GetLastStakeModifier: null pindex");
}
// Get selection interval section (in seconds)
-static int64 GetStakeModifierSelectionIntervalSection(int nSection)
+static int64_t GetStakeModifierSelectionIntervalSection(int 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 GetStakeModifierSelectionInterval()
+static int64_t GetStakeModifierSelectionInterval()
{
- int64 nSelectionInterval = 0;
+ int64_t nSelectionInterval = 0;
for (int 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, uint256> >& vSortedByTimestamp,
- map<uint256, const CBlockIndex*>& mapSelectedBlocks,
- int64 nSelectionIntervalStop, uint64 nStakeModifierPrev,
- const CBlockIndex** pindexSelected)
+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, uint256)& item, vSortedByTimestamp)
+ 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());
// 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& nStakeModifier, bool& fGeneratedStakeModifier)
+bool ComputeNextStakeModifier(const CBlockIndex* pindexCurrent, uint64_t& nStakeModifier, bool& fGeneratedStakeModifier)
{
nStakeModifier = 0;
fGeneratedStakeModifier = false;
+ const CBlockIndex* pindexPrev = pindexCurrent->pprev;
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 nModifierTime = 0;
+ 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"PRI64x" time=%s\n", nStakeModifier, DateTimeStrFormat(nModifierTime).c_str());
+ printf("ComputeNextStakeModifier: prev modifier=0x%016" PRIx64 " time=%s epoch=%u\n", nStakeModifier, DateTimeStrFormat(nModifierTime).c_str(), (unsigned int)nModifierTime);
}
if (nModifierTime / nModifierInterval >= pindexPrev->GetBlockTime() / nModifierInterval)
+ {
+ if (fDebug)
+ {
+ printf("ComputeNextStakeModifier: no new interval keep current modifier: pindexPrev nHeight=%d nTime=%u\n", pindexPrev->nHeight, (unsigned int)pindexPrev->GetBlockTime());
+ }
return true;
+ }
+ if (nModifierTime / nModifierInterval >= pindexCurrent->GetBlockTime() / nModifierInterval)
+ {
+ // fixed interval protocol requires current block timestamp also be in a different modifier interval
+ if (IsFixedModifierInterval(pindexCurrent->nTime))
+ {
+ if (fDebug)
+ {
+ printf("ComputeNextStakeModifier: no new interval keep current modifier: pindexCurrent nHeight=%d nTime=%u\n", pindexCurrent->nHeight, (unsigned int)pindexCurrent->GetBlockTime());
+ }
+ return true;
+ }
+ else
+ {
+ if (fDebug)
+ {
+ printf("ComputeNextStakeModifier: old modifier at block %s not meeting fixed modifier interval: pindexCurrent nHeight=%d nTime=%u\n", pindexCurrent->GetBlockHash().ToString().c_str(), pindexCurrent->nHeight, (unsigned int)pindexCurrent->GetBlockTime());
+ }
+ }
+ }
// Sort candidate blocks by timestamp
- vector<pair<int64, uint256> > vSortedByTimestamp;
+ vector<pair<int64_t, uint256> > vSortedByTimestamp;
vSortedByTimestamp.reserve(64 * nModifierInterval / nStakeTargetSpacing);
- int64 nSelectionInterval = GetStakeModifierSelectionInterval();
- int64 nSelectionIntervalStart = (pindexPrev->GetBlockTime() / nModifierInterval) * nModifierInterval - nSelectionInterval;
+ int64_t nSelectionInterval = GetStakeModifierSelectionInterval();
+ int64_t nSelectionIntervalStart = (pindexPrev->GetBlockTime() / nModifierInterval) * nModifierInterval - nSelectionInterval;
const CBlockIndex* pindex = pindexPrev;
while (pindex && pindex->GetBlockTime() >= nSelectionIntervalStart)
{
sort(vSortedByTimestamp.begin(), vSortedByTimestamp.end());
// Select 64 blocks from candidate blocks to generate stake modifier
- uint64 nStakeModifierNew = 0;
- int64 nSelectionIntervalStop = nSelectionIntervalStart;
+ uint64_t nStakeModifierNew = 0;
+ int64_t nSelectionIntervalStop = nSelectionIntervalStart;
map<uint256, const CBlockIndex*> mapSelectedBlocks;
for (int nRound=0; nRound<min(64, (int)vSortedByTimestamp.size()); nRound++)
{
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)pindex->GetStakeEntropyBit()) << nRound);
+ 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());
+ 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)
{
- printf("ComputeNextStakeModifier: new modifier=0x%016"PRI64x" time=%s\n", nStakeModifierNew, DateTimeStrFormat(pindexPrev->GetBlockTime()).c_str());
+ printf("ComputeNextStakeModifier: new modifier=0x%016" PRIx64 " time=%s\n", nStakeModifierNew, DateTimeStrFormat(pindexPrev->GetBlockTime()).c_str());
}
nStakeModifier = nStakeModifierNew;
// 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& nStakeModifier, int& nStakeModifierHeight, int64& nStakeModifierTime, bool fPrintProofOfStake)
+static bool GetKernelStakeModifier(uint256 hashBlockFrom, uint64_t& nStakeModifier, int& nStakeModifierHeight, int64_t& nStakeModifierTime, bool fPrintProofOfStake)
{
nStakeModifier = 0;
if (!mapBlockIndex.count(hashBlockFrom))
const CBlockIndex* pindexFrom = mapBlockIndex[hashBlockFrom];
nStakeModifierHeight = pindexFrom->nHeight;
nStakeModifierTime = pindexFrom->GetBlockTime();
- int64 nStakeModifierSelectionInterval = GetStakeModifierSelectionInterval();
+ int64_t nStakeModifierSelectionInterval = GetStakeModifierSelectionInterval();
const CBlockIndex* pindex = pindexFrom;
// loop to find the stake modifier later by a selection interval
while (nStakeModifierTime < pindexFrom->GetBlockTime() + nStakeModifierSelectionInterval)
return true;
}
+bool GetKernelStakeModifier(uint256 hashBlockFrom, uint64_t& nStakeModifier)
+{
+ int nStakeModifierHeight;
+ int64_t nStakeModifierTime;
+
+ return GetKernelStakeModifier(hashBlockFrom, nStakeModifier, nStakeModifierHeight, nStakeModifierTime, false);
+}
+
+
// ppcoin kernel protocol
// coinstake must meet hash target according to the protocol:
// kernel (input 0) must meet the formula
// 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:
-// (v0.3) scrambles computation to make it very difficult to precompute
-// future proof-of-stake at the time of the coin's confirmation
-// (v0.2) nBits (deprecated): encodes all past block timestamps
+// 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
// quantities so as to generate blocks faster, degrading the system back into
// a proof-of-work situation.
//
-bool CheckStakeKernelHash(unsigned int nBits, const CBlock& blockFrom, unsigned int nTxPrevOffset, const CTransaction& txPrev, const COutPoint& prevout, unsigned int nTimeTx, uint256& hashProofOfStake, bool fPrintProofOfStake)
+bool CheckStakeKernelHash(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");
- unsigned int nTimeBlockFrom = blockFrom.GetBlockTime();
+ uint32_t nTimeBlockFrom = blockFrom.GetBlockTime();
if (nTimeBlockFrom + nStakeMinAge > nTimeTx) // Min age requirement
return error("CheckStakeKernelHash() : min age violation");
CBigNum bnTargetPerCoinDay;
bnTargetPerCoinDay.SetCompact(nBits);
- int64 nValueIn = txPrev.vout[prevout.n].nValue;
+ int64_t nValueIn = txPrev.vout[prevout.n].nValue;
- int64 nTimeWeight;
+ uint256 hashBlockFrom = blockFrom.GetHash();
- // Kernel hash weight starts from 0 at the 30-day min age
- // this change increases active coins participating the hash and helps
- // to secure the network when proof-of-stake difficulty is low
- //
- if(fTestNet || (STAKEWEIGHT_SWITCH_TIME < nTimeTx))
- {
- // New rule since 01 Jan 2014: Maximum TimeWeight is 90 days.
- nTimeWeight = min((int64)nTimeTx - txPrev.nTime - nStakeMinAge, (int64)nStakeMaxAge);
- }
- else
- {
- // Current rule: Maximum TimeWeight is 60 days.
- nTimeWeight = min((int64)nTimeTx - txPrev.nTime, (int64)nStakeMaxAge) - nStakeMinAge;
- }
-
- CBigNum bnCoinDayWeight = CBigNum(nValueIn) * nTimeWeight / COIN / (24 * 60 * 60);
+ 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 nStakeModifier = 0;
+ uint64_t nStakeModifier = 0;
int nStakeModifierHeight = 0;
- int64 nStakeModifierTime = 0;
+ int64_t nStakeModifierTime = 0;
- if (!GetKernelStakeModifier(blockFrom.GetHash(), nStakeModifier, nStakeModifierHeight, nStakeModifierTime, fPrintProofOfStake))
+ if (!GetKernelStakeModifier(hashBlockFrom, nStakeModifier, nStakeModifierHeight, nStakeModifierTime, fPrintProofOfStake))
return false;
ss << nStakeModifier;
hashProofOfStake = Hash(ss.begin(), ss.end());
if (fPrintProofOfStake)
{
- printf("CheckStakeKernelHash() : using modifier 0x%016"PRI64x" at height=%d timestamp=%s for block from height=%d timestamp=%s\n",
+ 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[blockFrom.GetHash()]->nHeight,
+ mapBlockIndex[hashBlockFrom]->nHeight,
DateTimeStrFormat(blockFrom.GetBlockTime()).c_str());
- printf("CheckStakeKernelHash() : check protocol=%s modifier=0x%016"PRI64x" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n",
- "0.3",
+ printf("CheckStakeKernelHash() : check modifier=0x%016" PRIx64 " nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashTarget=%s hashProof=%s\n",
nStakeModifier,
nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx,
- hashProofOfStake.ToString().c_str());
+ targetProofOfStake.ToString().c_str(), hashProofOfStake.ToString().c_str());
}
// Now check if proof-of-stake hash meets target protocol
return false;
if (fDebug && !fPrintProofOfStake)
{
- printf("CheckStakeKernelHash() : using modifier 0x%016"PRI64x" at height=%d timestamp=%s for block from height=%d timestamp=%s\n",
+ 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[blockFrom.GetHash()]->nHeight,
+ mapBlockIndex[hashBlockFrom]->nHeight,
DateTimeStrFormat(blockFrom.GetBlockTime()).c_str());
- printf("CheckStakeKernelHash() : pass protocol=%s modifier=0x%016"PRI64x" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n",
- "0.3",
+ printf("CheckStakeKernelHash() : pass modifier=0x%016" PRIx64 " nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashTarget=%s hashProof=%s\n",
nStakeModifier,
nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx,
- hashProofOfStake.ToString().c_str());
+ targetProofOfStake.ToString().c_str(), hashProofOfStake.ToString().c_str());
}
return true;
}
+// Precompute hashing state for static part of kernel
+void GetKernelMidstate(uint64_t nStakeModifier, uint32_t nBlockTime, uint32_t nTxOffset, uint32_t nInputTxTime, uint32_t nOut, SHA256_CTX &ctx)
+{
+ // Build static part of kernel
+ CDataStream ssKernel(SER_GETHASH, 0);
+ ssKernel << nStakeModifier;
+ ssKernel << nBlockTime << nTxOffset << nInputTxTime << nOut;
+ CDataStream::const_iterator it = ssKernel.begin();
+
+ // Init sha256 context and update it
+ // with first 24 bytes of kernel
+ SHA256_Init(&ctx);
+ SHA256_Update(&ctx, (unsigned char*)&it[0], 8 + 16);
+}
+
+// Scan given midstate for solution
+bool ScanMidstateForward(SHA256_CTX &ctx, uint32_t nBits, uint32_t nInputTxTime, int64_t nValueIn, std::pair<uint32_t, uint32_t> &SearchInterval, std::pair<uint256, uint32_t> &solution)
+{
+ CBigNum bnTargetPerCoinDay;
+ bnTargetPerCoinDay.SetCompact(nBits);
+
+ // Get maximum possible target to filter out the majority of obviously insufficient hashes
+ CBigNum bnMaxTargetPerCoinDay = bnTargetPerCoinDay * CBigNum(nValueIn) * nStakeMaxAge / COIN / (24 * 60 * 60);
+ uint256 maxTarget = bnMaxTargetPerCoinDay.getuint256();
+
+ SHA256_CTX ctxCopy = ctx;
+
+ // Search forward in time from the given timestamp
+ // Stopping search in case of shutting down
+ for (uint32_t nTimeTx=SearchInterval.first; nTimeTx<SearchInterval.second && !fShutdown; nTimeTx++)
+ {
+ // Complete first hashing iteration
+ uint256 hash1;
+ SHA256_Update(&ctxCopy, (unsigned char*)&nTimeTx, 4);
+ SHA256_Final((unsigned char*)&hash1, &ctxCopy);
+
+ // Restore context
+ ctxCopy = ctx;
+
+ // Finally, calculate kernel hash
+ uint256 hashProofOfStake;
+ SHA256((unsigned char*)&hash1, sizeof(hashProofOfStake), (unsigned char*)&hashProofOfStake);
+
+ // Skip if hash doesn't satisfy the maximum target
+ if (hashProofOfStake > maxTarget)
+ continue;
+
+ CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)nInputTxTime, (int64_t)nTimeTx) / COIN / (24 * 60 * 60);
+ CBigNum bnTargetProofOfStake = bnCoinDayWeight * bnTargetPerCoinDay;
+
+ if (bnTargetProofOfStake >= CBigNum(hashProofOfStake))
+ {
+ solution.first = hashProofOfStake;
+ solution.second = nTimeTx;
+
+ return true;
+ }
+ }
+
+ return false;
+}
+
+// Scan given midstate for solution
+bool ScanMidstateBackward(SHA256_CTX &ctx, uint32_t nBits, uint32_t nInputTxTime, int64_t nValueIn, std::pair<uint32_t, uint32_t> &SearchInterval, std::pair<uint256, uint32_t> &solution)
+{
+ CBigNum bnTargetPerCoinDay;
+ bnTargetPerCoinDay.SetCompact(nBits);
+
+ // Get maximum possible target to filter out the majority of obviously insufficient hashes
+ CBigNum bnMaxTargetPerCoinDay = bnTargetPerCoinDay * CBigNum(nValueIn) * nStakeMaxAge / COIN / (24 * 60 * 60);
+ uint256 maxTarget = bnMaxTargetPerCoinDay.getuint256();
+
+ SHA256_CTX ctxCopy = ctx;
+
+ // Search backward in time from the given timestamp
+ // Stopping search in case of shutting down
+ for (uint32_t nTimeTx=SearchInterval.first; nTimeTx>SearchInterval.second && !fShutdown; nTimeTx--)
+ {
+ // Complete first hashing iteration
+ uint256 hash1;
+ SHA256_Update(&ctxCopy, (unsigned char*)&nTimeTx, 4);
+ SHA256_Final((unsigned char*)&hash1, &ctxCopy);
+
+ // Restore context
+ ctxCopy = ctx;
+
+ // Finally, calculate kernel hash
+ uint256 hashProofOfStake;
+ SHA256((unsigned char*)&hash1, sizeof(hashProofOfStake), (unsigned char*)&hashProofOfStake);
+
+ // Skip if hash doesn't satisfy the maximum target
+ if (hashProofOfStake > maxTarget)
+ continue;
+
+ CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)nInputTxTime, (int64_t)nTimeTx) / COIN / (24 * 60 * 60);
+ CBigNum bnTargetProofOfStake = bnCoinDayWeight * bnTargetPerCoinDay;
+
+ if (bnTargetProofOfStake >= CBigNum(hashProofOfStake))
+ {
+ solution.first = hashProofOfStake;
+ solution.second = nTimeTx;
+
+ return true;
+ }
+ }
+
+ return false;
+}
+
// Check kernel hash target and coinstake signature
-bool CheckProofOfStake(const CTransaction& tx, unsigned int nBits, uint256& hashProofOfStake)
+bool CheckProofOfStake(const CTransaction& tx, unsigned int nBits, uint256& hashProofOfStake, uint256& targetProofOfStake)
{
if (!tx.IsCoinStake())
return error("CheckProofOfStake() : called on non-coinstake %s", tx.GetHash().ToString().c_str());
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
+
+#ifndef USE_LEVELDB
txdb.Close();
+#endif
// Verify signature
- if (!VerifySignature(txPrev, tx, 0, true, 0))
+ if (!VerifySignature(txPrev, tx, 0, MANDATORY_SCRIPT_VERIFY_FLAGS, 0))
return tx.DoS(100, error("CheckProofOfStake() : VerifySignature failed on coinstake %s", tx.GetHash().ToString().c_str()));
// Read block header
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(nBits, block, txindex.pos.nTxPos - txindex.pos.nBlockPos, txPrev, txin.prevout, tx.nTime, hashProofOfStake, fDebug))
+ if (!CheckStakeKernelHash(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 nTimeBlock, int64 nTimeTx)
-{
- // v0.3 protocol
- return (nTimeBlock == nTimeTx);
-}
-
// Get stake modifier checksum
-unsigned int GetStakeModifierChecksum(const CBlockIndex* pindex)
+uint32_t GetStakeModifierChecksum(const CBlockIndex* pindex)
{
assert (pindex->pprev || pindex->GetBlockHash() == (!fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet));
// Hash previous checksum with flags, hashProofOfStake and nStakeModifier
ss << pindex->nFlags << pindex->hashProofOfStake << pindex->nStakeModifier;
uint256 hashChecksum = Hash(ss.begin(), ss.end());
hashChecksum >>= (256 - 32);
- return hashChecksum.Get64();
+ return static_cast<uint32_t>(hashChecksum.Get64());
}
// Check stake modifier hard checkpoints
-bool CheckStakeModifierCheckpoints(int nHeight, unsigned int nStakeModifierChecksum)
+bool CheckStakeModifierCheckpoints(int nHeight, uint32_t nStakeModifierChecksum)
{
- if (fTestNet) return true; // Testnet has no checkpoints
- if (mapStakeModifierCheckpoints.count(nHeight))
- return nStakeModifierChecksum == mapStakeModifierCheckpoints[nHeight];
+ MapModifierCheckpoints& checkpoints = (fTestNet ? mapStakeModifierCheckpointsTestNet : mapStakeModifierCheckpoints);
+
+ if (checkpoints.count(nHeight))
+ return nStakeModifierChecksum == checkpoints[nHeight];
return true;
}