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authorBtcDrak <btcdrak@gmail.com>2016-02-12 20:02:46 +0000
committerBtcDrak <btcdrak@gmail.com>2016-02-14 11:29:40 +0000
commitc3c375226ebf98901849593b8ebfe8e8b69895c2 (patch)
treef7bc24864cbbc1782eb820e7a8a1c301a3d75e22 /src/script/interpreter.cpp
parent53e53a33c939949665f60d5eeb82abbb21f97128 (diff)
Separate CheckLockTime() and CheckSequence() logic
For the sake of a little repetition, make code more readable.
Diffstat (limited to 'src/script/interpreter.cpp')
-rw-r--r--src/script/interpreter.cpp46
1 files changed, 26 insertions, 20 deletions
diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index 4e87006f57..d4fe001d7a 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -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
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
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);