Precompute sighashes

This commit is contained in:
Pieter Wuille
2016-08-16 15:35:45 +02:00
committed by lateminer
parent 81e04cabfe
commit d8d19c532f
10 changed files with 72 additions and 26 deletions

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@@ -82,11 +82,11 @@ int bitcoinconsensus_verify_script(const unsigned char *scriptPubKey, unsigned i
if (tx.GetSerializeSize(SER_NETWORK, PROTOCOL_VERSION) != txToLen)
return set_error(err, bitcoinconsensus_ERR_TX_SIZE_MISMATCH);
// Regardless of the verification result, the tx did not error.
set_error(err, bitcoinconsensus_ERR_OK);
CAmount am(0);
return VerifyScript(tx.vin[nIn].scriptSig, CScript(scriptPubKey, scriptPubKey + scriptPubKeyLen), flags, TransactionSignatureChecker(&tx, nIn, am), NULL);
// Regardless of the verification result, the tx did not error.
set_error(err, bitcoinconsensus_ERR_OK);
CachedHashes cachedHashes(tx);
CAmount amount(0);
return VerifyScript(tx.vin[nIn].scriptSig, CScript(scriptPubKey, scriptPubKey + scriptPubKeyLen), flags, TransactionSignatureChecker(&tx, nIn, amount, cachedHashes), NULL);
} catch (const std::exception&) {
return set_error(err, bitcoinconsensus_ERR_TX_DESERIALIZE); // Error deserializing
}

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@@ -1140,9 +1140,40 @@ public:
}
};
uint256 GetPrevoutHash(const CTransaction& txTo) {
CHashWriter ss(SER_GETHASH, 0);
for (unsigned int n = 0; n < txTo.vin.size(); n++) {
ss << txTo.vin[n].prevout;
}
return ss.GetHash();
}
uint256 GetSequenceHash(const CTransaction& txTo) {
CHashWriter ss(SER_GETHASH, 0);
for (unsigned int n = 0; n < txTo.vin.size(); n++) {
ss << txTo.vin[n].nSequence;
}
return ss.GetHash();
}
uint256 GetOutputsHash(const CTransaction& txTo) {
CHashWriter ss(SER_GETHASH, 0);
for (unsigned int n = 0; n < txTo.vout.size(); n++) {
ss << txTo.vout[n];
}
return ss.GetHash();
}
} // anon namespace
uint256 SignatureHash(const CScript& scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType)
CachedHashes::CachedHashes(const CTransaction& txTo)
{
hashPrevouts = GetPrevoutHash(txTo);
hashSequence = GetSequenceHash(txTo);
hashOutputs = GetOutputsHash(txTo);
}
uint256 SignatureHash(const CScript& scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType, const CAmount& amount, const CachedHashes* cache)
{
static const uint256 one(uint256S("0000000000000000000000000000000000000000000000000000000000000001"));
if (nIn >= txTo.vin.size()) {
@@ -1185,7 +1216,7 @@ bool TransactionSignatureChecker::CheckSig(const vector<unsigned char>& vchSigIn
int nHashType = vchSig.back();
vchSig.pop_back();
uint256 sighash = SignatureHash(scriptCode, *txTo, nIn, nHashType);
uint256 sighash = SignatureHash(scriptCode, *txTo, nIn, nHashType, amount, this->cachedHashes);
if (!VerifySignature(vchSig, pubkey, sighash))
return false;

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@@ -102,7 +102,7 @@ enum
bool CheckSignatureEncoding(const std::vector<unsigned char> &vchSig, unsigned int flags, ScriptError* serror);
uint256 SignatureHash(const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType);
uint256 SignatureHash(const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType, const CAmount& amount, const PrecomputedTransactionData* cache = NULL);
class BaseSignatureChecker
{
@@ -130,12 +130,15 @@ class TransactionSignatureChecker : public BaseSignatureChecker
private:
const CTransaction* txTo;
unsigned int nIn;
const CAmount amount;
const CachedHashes* cachedHashes;
protected:
virtual bool VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& vchPubKey, const uint256& sighash) const;
public:
TransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn, const CAmount& amount) : txTo(txToIn), nIn(nInIn) {}
TransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn, const CAmount& amount) : txTo(txToIn), nIn(nInIn), amount(amountIn), cachedHashes(NULL) {}
TransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, const CachedHashes& cachedHashesIn) : txTo(txToIn), nIn(nInIn), amount(amountIn), cachedHashes(&cachedHashesIn) {}
bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode) const;
bool CheckLockTime(const CScriptNum& nLockTime) const;
bool CheckSequence(const CScriptNum& nSequence) const;

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@@ -22,7 +22,7 @@ private:
bool store;
public:
CachingTransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn, const CAmount& amount, bool storeIn) : TransactionSignatureChecker(txToIn, nInIn, amount), store(storeIn) {}
CachingTransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn, const CAmount& amount, bool storeIn, CachedHashes& cachedHashesIn) : TransactionSignatureChecker(txToIn, nInIn, amount, cachedHashesIn), store(storeIn) {}
bool VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& vchPubKey, const uint256& sighash) const;
};