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Separate CheckLockTime() and CheckSequence() logic

For the sake of a little repetition, make code more readable.
0.13
BtcDrak 9 years ago
parent
commit
c3c375226e
  1. 46
      src/script/interpreter.cpp

46
src/script/interpreter.cpp

@ -1157,33 +1157,27 @@ bool TransactionSignatureChecker::CheckSig(const vector<unsigned char>& vchSigIn @@ -1157,33 +1157,27 @@ bool TransactionSignatureChecker::CheckSig(const vector<unsigned char>& vchSigIn
return true;
}
static bool VerifyLockTime(int64_t txToLockTime, int64_t nThreshold, const CScriptNum& nLockTime)
bool TransactionSignatureChecker::CheckLockTime(const CScriptNum& nLockTime) const
{
// There are two kinds of nLockTime: lock-by-blockheight
// and lock-by-blocktime, distinguished by whether
// nLockTime < nThreshold (either LOCKTIME_THRESHOLD or
// CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG).
// nLockTime < LOCKTIME_THRESHOLD.
//
// We want to compare apples to apples, so fail the script
// unless the type of nLockTime being tested is the same as
// the nLockTime in the transaction.
if (!(
(txToLockTime < nThreshold && nLockTime < nThreshold) ||
(txToLockTime >= nThreshold && nLockTime >= nThreshold)
(txTo->nLockTime < LOCKTIME_THRESHOLD && nLockTime < LOCKTIME_THRESHOLD) ||
(txTo->nLockTime >= LOCKTIME_THRESHOLD && nLockTime >= LOCKTIME_THRESHOLD)
))
return false;
// Now that we know we're comparing apples-to-apples, the
// comparison is a simple numeric one.
if (nLockTime > txToLockTime)
if (nLockTime > (int64_t)txTo->nLockTime)
return false;
return true;
}
bool TransactionSignatureChecker::CheckLockTime(const CScriptNum& nLockTime) const
{
// The nLockTime feature can be disabled and thus
// Finally the nLockTime feature can be disabled and thus
// CHECKLOCKTIMEVERIFY bypassed if every txin has been
// finalized by setting nSequence to maxint. The
// transaction would be allowed into the blockchain, making
@ -1196,9 +1190,6 @@ bool TransactionSignatureChecker::CheckLockTime(const CScriptNum& nLockTime) con @@ -1196,9 +1190,6 @@ bool TransactionSignatureChecker::CheckLockTime(const CScriptNum& nLockTime) con
if (CTxIn::SEQUENCE_FINAL == txTo->vin[nIn].nSequence)
return false;
if (!::VerifyLockTime((int64_t)txTo->nLockTime, LOCKTIME_THRESHOLD, nLockTime))
return false;
return true;
}
@ -1221,17 +1212,32 @@ bool TransactionSignatureChecker::CheckSequence(const CScriptNum& nSequence) con @@ -1221,17 +1212,32 @@ bool TransactionSignatureChecker::CheckSequence(const CScriptNum& nSequence) con
return false;
// Mask off any bits that do not have consensus-enforced meaning
// before doing the integer comparisons of ::VerifyLockTime.
const uint32_t nLockTimeMask = CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG
| CTxIn::SEQUENCE_LOCKTIME_MASK;
// before doing the integer comparisons
const uint32_t nLockTimeMask = CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG | CTxIn::SEQUENCE_LOCKTIME_MASK;
const int64_t txToSequenceMasked = txToSequence & nLockTimeMask;
const CScriptNum nSequenceMasked = nSequence & nLockTimeMask;
// There are two kinds of nSequence: lock-by-blockheight
// and lock-by-blocktime, distinguished by whether
// nSequenceMasked < CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG.
//
// We want to compare apples to apples, so fail the script
// unless the type of nSequenceMasked being tested is the same as
// the nSequenceMasked in the transaction.
if (!(
(txToSequenceMasked < CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG && nSequenceMasked < CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG) ||
(txToSequenceMasked >= CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG && nSequenceMasked >= CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG)
))
return false;
if (!::VerifyLockTime(txToSequence & nLockTimeMask, CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG, nSequence & nLockTimeMask))
// Now that we know we're comparing apples-to-apples, the
// comparison is a simple numeric one.
if (nSequenceMasked > txToSequenceMasked)
return false;
return true;
}
bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror)
{
set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR);

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