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Simplify counting of P2SH sigops to match BIP 16 (thanks to Matt Corallo for prompting this).

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This also removes an un-needed sigops-per-byte check when accepting transactions to the memory pool (un-needed assuming only standard transactions are being accepted). And it only counts P2SH sigops after the switchover date.
This commit is contained in:
Gavin Andresen 2012-01-20 17:07:40 -05:00
parent 1240a1b0a8
commit 137d0685a4
4 changed files with 53 additions and 52 deletions
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78
src/main.cpp
View file

@ -503,20 +503,17 @@ bool CTransaction::AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs, bool* pfMi
if (!AreInputsStandard(mapInputs))
return error("AcceptToMemoryPool() : nonstandard transaction input");
// Note: if you modify this code to accept non-standard transactions, then
// you should add code here to check that the transaction does a
// reasonable number of ECDSA signature verifications.
int64 nFees = GetValueIn(mapInputs)-GetValueOut();
int nSigOps = GetSigOpCount(mapInputs);
unsigned int nSize = ::GetSerializeSize(*this, SER_NETWORK);
// Don't accept it if it can't get into a block
if (nFees < GetMinFee(1000, true, GMF_RELAY))
return error("AcceptToMemoryPool() : not enough fees");
// Checking ECDSA signatures is a CPU bottleneck, so to avoid denial-of-service
// attacks disallow transactions with more than one SigOp per 65 bytes.
// 65 bytes because that is the minimum size of an ECDSA signature
if (nSigOps > nSize / 65 || nSize < 100)
return error("AcceptToMemoryPool() : transaction with out-of-bounds SigOpCount");
// Continuously rate-limit free transactions
// This mitigates 'penny-flooding' -- sending thousands of free transactions just to
// be annoying or make other's transactions take longer to confirm.
@ -1013,7 +1010,7 @@ int64 CTransaction::GetValueIn(const MapPrevTx& inputs) const
}
int CTransaction::GetSigOpCount(const MapPrevTx& inputs) const
int CTransaction::GetP2SHSigOpCount(const MapPrevTx& inputs) const
{
if (IsCoinBase())
return 0;
@ -1021,14 +1018,16 @@ int CTransaction::GetSigOpCount(const MapPrevTx& inputs) const
int nSigOps = 0;
for (int i = 0; i < vin.size(); i++)
{
nSigOps += GetOutputFor(vin[i], inputs).scriptPubKey.GetSigOpCount(vin[i].scriptSig);
const CTxOut& prevout = GetOutputFor(vin[i], inputs);
if (prevout.scriptPubKey.IsPayToScriptHash())
nSigOps += prevout.scriptPubKey.GetSigOpCount(vin[i].scriptSig);
}
return nSigOps;
}
bool CTransaction::ConnectInputs(MapPrevTx inputs,
map<uint256, CTxIndex>& mapTestPool, const CDiskTxPos& posThisTx,
const CBlockIndex* pindexBlock, bool fBlock, bool fMiner)
const CBlockIndex* pindexBlock, bool fBlock, bool fMiner, bool fStrictPayToScriptHash)
{
// Take over previous transactions' spent pointers
// fBlock is true when this is called from AcceptBlock when a new best-block is added to the blockchain
@ -1065,20 +1064,6 @@ bool CTransaction::ConnectInputs(MapPrevTx inputs,
if (!MoneyRange(txPrev.vout[prevout.n].nValue) || !MoneyRange(nValueIn))
return DoS(100, error("ConnectInputs() : txin values out of range"));
bool fStrictPayToScriptHash = true;
if (fBlock)
{
// To avoid being on the short end of a block-chain split,
// don't do secondary validation of pay-to-script-hash transactions
// until blocks with timestamps after paytoscripthashtime:
int64 nEvalSwitchTime = GetArg("paytoscripthashtime", 1329264000); // Feb 15, 2012
fStrictPayToScriptHash = (pindexBlock->nTime >= nEvalSwitchTime);
}
// if !fBlock, then always be strict-- don't accept
// invalid-under-new-rules pay-to-script-hash transactions into
// our memory pool (don't relay them, don't include them
// in blocks we mine).
// Skip ECDSA signature verification when connecting blocks (fBlock=true)
// before the last blockchain checkpoint. This is safe because block merkle hashes are
// still computed and checked, and any change will be caught at the next checkpoint.
@ -1189,6 +1174,12 @@ bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex)
if (!CheckBlock())
return false;
// To avoid being on the short end of a block-chain split,
// don't do secondary validation of pay-to-script-hash transactions
// until blocks with timestamps after paytoscripthashtime:
int64 nEvalSwitchTime = GetArg("-paytoscripthashtime", 1329264000); // Feb 15, 2012
bool fStrictPayToScriptHash = (pindex->nTime >= nEvalSwitchTime);
//// issue here: it doesn't know the version
unsigned int nTxPos = pindex->nBlockPos + ::GetSerializeSize(CBlock(), SER_DISK) - 1 + GetSizeOfCompactSize(vtx.size());
@ -1197,6 +1188,10 @@ bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex)
int nSigOps = 0;
BOOST_FOREACH(CTransaction& tx, vtx)
{
nSigOps += tx.GetLegacySigOpCount();
if (nSigOps > MAX_BLOCK_SIGOPS)
return DoS(100, error("ConnectBlock() : too many sigops"));
CDiskTxPos posThisTx(pindex->nFile, pindex->nBlockPos, nTxPos);
nTxPos += ::GetSerializeSize(tx, SER_DISK);
@ -1206,17 +1201,19 @@ bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex)
if (!tx.FetchInputs(txdb, mapQueuedChanges, true, false, mapInputs))
return false;
int nTxOps = tx.GetSigOpCount(mapInputs);
nSigOps += nTxOps;
if (nSigOps > MAX_BLOCK_SIGOPS)
return DoS(100, error("ConnectBlock() : too many sigops"));
// There is a different MAX_BLOCK_SIGOPS check in AcceptBlock();
// a block must satisfy both to make it into the best-chain
// (AcceptBlock() is always called before ConnectBlock())
if (fStrictPayToScriptHash)
{
// Add in sigops done by pay-to-script-hash inputs;
// this is to prevent a "rogue miner" from creating
// an incredibly-expensive-to-validate block.
nSigOps += tx.GetP2SHSigOpCount(mapInputs);
if (nSigOps > MAX_BLOCK_SIGOPS)
return DoS(100, error("ConnectBlock() : too many sigops"));
}
nFees += tx.GetValueIn(mapInputs)-tx.GetValueOut();
if (!tx.ConnectInputs(mapInputs, mapQueuedChanges, posThisTx, pindex, true, false))
if (!tx.ConnectInputs(mapInputs, mapQueuedChanges, posThisTx, pindex, true, false, fStrictPayToScriptHash))
return false;
}
@ -1500,9 +1497,6 @@ bool CBlock::CheckBlock() const
if (!tx.CheckTransaction())
return DoS(tx.nDoS, error("CheckBlock() : CheckTransaction failed"));
// Pre-pay-to-script-hash (before version 0.6), this is how sigops
// were counted; there is another check in ConnectBlock when
// transaction inputs are fetched to count pay-to-script-hash sigops:
int nSigOps = 0;
BOOST_FOREACH(const CTransaction& tx, vtx)
{
@ -3036,8 +3030,7 @@ CBlock* CreateNewBlock(CReserveKey& reservekey)
map<uint256, CTxIndex> mapTestPool;
uint64 nBlockSize = 1000;
uint64 nBlockTx = 0;
int nBlockSigOps1 = 100; // pre-0.6 count of sigOps
int nBlockSigOps2 = 100; // post-0.6 count of sigOps
int nBlockSigOps = 100;
while (!mapPriority.empty())
{
// Take highest priority transaction off priority queue
@ -3051,8 +3044,8 @@ CBlock* CreateNewBlock(CReserveKey& reservekey)
continue;
// Legacy limits on sigOps:
int nTxSigOps1 = tx.GetLegacySigOpCount();
if (nBlockSigOps1 + nTxSigOps1 >= MAX_BLOCK_SIGOPS)
int nTxSigOps = tx.GetLegacySigOpCount();
if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
continue;
// Transaction fee required depends on block size
@ -3070,8 +3063,8 @@ CBlock* CreateNewBlock(CReserveKey& reservekey)
if (nFees < nMinFee)
continue;
int nTxSigOps2 = tx.GetSigOpCount(mapInputs);
if (nBlockSigOps2 + nTxSigOps2 >= MAX_BLOCK_SIGOPS)
nTxSigOps += tx.GetP2SHSigOpCount(mapInputs);
if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
continue;
if (!tx.ConnectInputs(mapInputs, mapTestPoolTmp, CDiskTxPos(1,1,1), pindexPrev, false, true))
@ -3083,8 +3076,7 @@ CBlock* CreateNewBlock(CReserveKey& reservekey)
pblock->vtx.push_back(tx);
nBlockSize += nTxSize;
++nBlockTx;
nBlockSigOps1 += nTxSigOps1;
nBlockSigOps2 += nTxSigOps2;
nBlockSigOps += nTxSigOps;
// Add transactions that depend on this one to the priority queue
uint256 hash = tx.GetHash();

8
src/main.h
View file

@ -528,14 +528,13 @@ public:
*/
int GetLegacySigOpCount() const;
/** Count ECDSA signature operations the new (0.6-and-later) way
This is a better measure of how expensive it is to process this transaction.
/** Count ECDSA signature operations in pay-to-script-hash inputs.
@param[in] mapInputs Map of previous transactions that have outputs we're spending
@return maximum number of sigops required to validate this transaction's inputs
@see CTransaction::FetchInputs
*/
int GetSigOpCount(const MapPrevTx& mapInputs) const;
int GetP2SHSigOpCount(const MapPrevTx& mapInputs) const;
/** Amount of bitcoins spent by this transaction.
@return sum of all outputs (note: does not include fees)
@ -698,11 +697,12 @@ public:
@param[in] pindexBlock
@param[in] fBlock true if called from ConnectBlock
@param[in] fMiner true if called from CreateNewBlock
@param[in] fStrictPayToScriptHash true if fully validating p2sh transactions
@return Returns true if all checks succeed
*/
bool ConnectInputs(MapPrevTx inputs,
std::map<uint256, CTxIndex>& mapTestPool, const CDiskTxPos& posThisTx,
const CBlockIndex* pindexBlock, bool fBlock, bool fMiner);
const CBlockIndex* pindexBlock, bool fBlock, bool fMiner, bool fStrictPayToScriptHash=true);
bool ClientConnectInputs();
bool CheckTransaction() const;
bool AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs=true, bool* pfMissingInputs=NULL);

17
src/test/script_P2SH_tests.cpp
View file

@ -255,7 +255,7 @@ BOOST_AUTO_TEST_CASE(AreInputsStandard)
}
CTransaction txFrom;
txFrom.vout.resize(5);
txFrom.vout.resize(6);
// First three are standard:
CScript pay1; pay1.SetBitcoinAddress(key[0].GetPubKey());
@ -267,12 +267,18 @@ BOOST_AUTO_TEST_CASE(AreInputsStandard)
txFrom.vout[1].scriptPubKey = pay1;
txFrom.vout[2].scriptPubKey = pay1of3;
// Last two non-standard:
// Last three non-standard:
CScript empty;
keystore.AddCScript(empty);
txFrom.vout[3].scriptPubKey = empty;
// Can't use SetPayToScriptHash, it checks for the empty Script. So:
txFrom.vout[4].scriptPubKey << OP_HASH160 << Hash160(empty) << OP_EQUAL;
CScript oneOfEleven;
oneOfEleven << OP_1;
for (int i = 0; i < 11; i++)
oneOfEleven << key[0].GetPubKey();
oneOfEleven << OP_11 << OP_CHECKMULTISIG;
txFrom.vout[5].scriptPubKey.SetPayToScriptHash(oneOfEleven);
mapInputs[txFrom.GetHash()] = make_pair(CTxIndex(), txFrom);
@ -292,16 +298,21 @@ BOOST_AUTO_TEST_CASE(AreInputsStandard)
BOOST_CHECK(SignSignature(keystore, txFrom, txTo, 2));
BOOST_CHECK(txTo.AreInputsStandard(mapInputs));
BOOST_CHECK_EQUAL(txTo.GetP2SHSigOpCount(mapInputs), 1);
CTransaction txToNonStd;
txToNonStd.vout.resize(1);
txToNonStd.vout[0].scriptPubKey.SetBitcoinAddress(key[1].GetPubKey());
txToNonStd.vin.resize(1);
txToNonStd.vin.resize(2);
txToNonStd.vin[0].prevout.n = 4;
txToNonStd.vin[0].prevout.hash = txFrom.GetHash();
txToNonStd.vin[0].scriptSig << Serialize(empty);
txToNonStd.vin[1].prevout.n = 5;
txToNonStd.vin[1].prevout.hash = txFrom.GetHash();
txToNonStd.vin[1].scriptSig << OP_0 << Serialize(oneOfEleven);
BOOST_CHECK(!txToNonStd.AreInputsStandard(mapInputs));
BOOST_CHECK_EQUAL(txToNonStd.GetP2SHSigOpCount(mapInputs), 11);
txToNonStd.vin[0].scriptSig.clear();
BOOST_CHECK(!txToNonStd.AreInputsStandard(mapInputs));

2
src/test/transaction_tests.cpp
View file

@ -78,7 +78,6 @@ BOOST_AUTO_TEST_CASE(test_Get)
t1.vout[0].scriptPubKey << OP_1;
BOOST_CHECK(t1.AreInputsStandard(dummyInputs));
BOOST_CHECK_EQUAL(t1.GetSigOpCount(dummyInputs), 3);
BOOST_CHECK_EQUAL(t1.GetValueIn(dummyInputs), (50+21+22)*CENT);
}
@ -103,7 +102,6 @@ BOOST_AUTO_TEST_CASE(test_GetThrow)
t1.vout[0].scriptPubKey << OP_1;
BOOST_CHECK_THROW(t1.AreInputsStandard(missingInputs), runtime_error);
BOOST_CHECK_THROW(t1.GetSigOpCount(missingInputs), runtime_error);
BOOST_CHECK_THROW(t1.GetValueIn(missingInputs), runtime_error);
}