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-rw-r--r--src/script/interpreter.cpp83
-rw-r--r--src/script/interpreter.h11
-rw-r--r--src/script/script.h12
-rw-r--r--src/script/script_error.cpp4
-rw-r--r--src/script/script_error.h4
-rw-r--r--src/script/standard.h3
6 files changed, 111 insertions, 6 deletions
diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index 84a7432fdb..0b78fdf5a8 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -335,9 +335,51 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
// Control
//
case OP_NOP:
- break;
+ break;
+
+ case OP_CHECKLOCKTIMEVERIFY:
+ {
+ if (!(flags & SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY)) {
+ // not enabled; treat as a NOP2
+ if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) {
+ return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS);
+ }
+ break;
+ }
+
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+
+ // Note that elsewhere numeric opcodes are limited to
+ // operands in the range -2**31+1 to 2**31-1, however it is
+ // legal for opcodes to produce results exceeding that
+ // range. This limitation is implemented by CScriptNum's
+ // default 4-byte limit.
+ //
+ // If we kept to that limit we'd have a year 2038 problem,
+ // even though the nLockTime field in transactions
+ // themselves is uint32 which only becomes meaningless
+ // after the year 2106.
+ //
+ // Thus as a special case we tell CScriptNum to accept up
+ // to 5-byte bignums, which are good until 2**39-1, well
+ // beyond the 2**32-1 limit of the nLockTime field itself.
+ const CScriptNum nLockTime(stacktop(-1), fRequireMinimal, 5);
+
+ // In the rare event that the argument may be < 0 due to
+ // some arithmetic being done first, you can always use
+ // 0 MAX CHECKLOCKTIMEVERIFY.
+ if (nLockTime < 0)
+ return set_error(serror, SCRIPT_ERR_NEGATIVE_LOCKTIME);
+
+ // Actually compare the specified lock time with the transaction.
+ if (!checker.CheckLockTime(nLockTime))
+ return set_error(serror, SCRIPT_ERR_UNSATISFIED_LOCKTIME);
+
+ break;
+ }
- case OP_NOP1: case OP_NOP2: case OP_NOP3: case OP_NOP4: case OP_NOP5:
+ case OP_NOP1: case OP_NOP3: case OP_NOP4: case OP_NOP5:
case OP_NOP6: case OP_NOP7: case OP_NOP8: case OP_NOP9: case OP_NOP10:
{
if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS)
@@ -1084,6 +1126,43 @@ bool TransactionSignatureChecker::CheckSig(const vector<unsigned char>& vchSigIn
return true;
}
+bool TransactionSignatureChecker::CheckLockTime(const CScriptNum& nLockTime) const
+{
+ // There are two times of nLockTime: lock-by-blockheight
+ // and lock-by-blocktime, distinguished by whether
+ // 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 (!(
+ (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 > (int64_t)txTo->nLockTime)
+ return false;
+
+ // 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
+ // the opcode ineffective.
+ //
+ // Testing if this vin is not final is sufficient to
+ // prevent this condition. Alternatively we could test all
+ // inputs, but testing just this input minimizes the data
+ // required to prove correct CHECKLOCKTIMEVERIFY execution.
+ if (txTo->vin[nIn].IsFinal())
+ 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);
diff --git a/src/script/interpreter.h b/src/script/interpreter.h
index fc64438f68..35d572f0ad 100644
--- a/src/script/interpreter.h
+++ b/src/script/interpreter.h
@@ -76,6 +76,11 @@ enum
// (softfork safe, BIP62 rule 6)
// Note: CLEANSTACK should never be used without P2SH.
SCRIPT_VERIFY_CLEANSTACK = (1U << 8),
+
+ // Verify CHECKLOCKTIMEVERIFY
+ //
+ // See BIP65 for details.
+ SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY = (1U << 9),
};
uint256 SignatureHash(const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType);
@@ -88,6 +93,11 @@ public:
return false;
}
+ virtual bool CheckLockTime(const CScriptNum& nLockTime) const
+ {
+ return false;
+ }
+
virtual ~BaseSignatureChecker() {}
};
@@ -103,6 +113,7 @@ protected:
public:
TransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn) : txTo(txToIn), nIn(nInIn) {}
bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode) const;
+ bool CheckLockTime(const CScriptNum& nLockTime) const;
};
class MutableTransactionSignatureChecker : public TransactionSignatureChecker
diff --git a/src/script/script.h b/src/script/script.h
index d5045005be..c09899aabd 100644
--- a/src/script/script.h
+++ b/src/script/script.h
@@ -19,6 +19,10 @@
static const unsigned int MAX_SCRIPT_ELEMENT_SIZE = 520; // bytes
+// Threshold for nLockTime: below this value it is interpreted as block number,
+// otherwise as UNIX timestamp.
+static const unsigned int LOCKTIME_THRESHOLD = 500000000; // Tue Nov 5 00:53:20 1985 UTC
+
template <typename T>
std::vector<unsigned char> ToByteVector(const T& in)
{
@@ -151,6 +155,7 @@ enum opcodetype
// expansion
OP_NOP1 = 0xb0,
OP_NOP2 = 0xb1,
+ OP_CHECKLOCKTIMEVERIFY = OP_NOP2,
OP_NOP3 = 0xb2,
OP_NOP4 = 0xb3,
OP_NOP5 = 0xb4,
@@ -196,7 +201,10 @@ public:
m_value = n;
}
- explicit CScriptNum(const std::vector<unsigned char>& vch, bool fRequireMinimal)
+ static const size_t nDefaultMaxNumSize = 4;
+
+ explicit CScriptNum(const std::vector<unsigned char>& vch, bool fRequireMinimal,
+ const size_t nMaxNumSize = nDefaultMaxNumSize)
{
if (vch.size() > nMaxNumSize) {
throw scriptnum_error("script number overflow");
@@ -319,8 +327,6 @@ public:
return result;
}
- static const size_t nMaxNumSize = 4;
-
private:
static int64_t set_vch(const std::vector<unsigned char>& vch)
{
diff --git a/src/script/script_error.cpp b/src/script/script_error.cpp
index d8ecfde1d7..f1aa1fb408 100644
--- a/src/script/script_error.cpp
+++ b/src/script/script_error.cpp
@@ -47,6 +47,10 @@ const char* ScriptErrorString(const ScriptError serror)
return "OP_RETURN was encountered";
case SCRIPT_ERR_UNBALANCED_CONDITIONAL:
return "Invalid OP_IF construction";
+ case SCRIPT_ERR_NEGATIVE_LOCKTIME:
+ return "Negative locktime";
+ case SCRIPT_ERR_UNSATISFIED_LOCKTIME:
+ return "Locktime requirement not satisfied";
case SCRIPT_ERR_SIG_HASHTYPE:
return "Signature hash type missing or not understood";
case SCRIPT_ERR_SIG_DER:
diff --git a/src/script/script_error.h b/src/script/script_error.h
index 6365680b29..bb10b8a293 100644
--- a/src/script/script_error.h
+++ b/src/script/script_error.h
@@ -35,6 +35,10 @@ typedef enum ScriptError_t
SCRIPT_ERR_INVALID_ALTSTACK_OPERATION,
SCRIPT_ERR_UNBALANCED_CONDITIONAL,
+ /* OP_CHECKLOCKTIMEVERIFY */
+ SCRIPT_ERR_NEGATIVE_LOCKTIME,
+ SCRIPT_ERR_UNSATISFIED_LOCKTIME,
+
/* BIP62 */
SCRIPT_ERR_SIG_HASHTYPE,
SCRIPT_ERR_SIG_DER,
diff --git a/src/script/standard.h b/src/script/standard.h
index a8b0acc981..3b401dfe4f 100644
--- a/src/script/standard.h
+++ b/src/script/standard.h
@@ -50,7 +50,8 @@ static const unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY
SCRIPT_VERIFY_MINIMALDATA |
SCRIPT_VERIFY_NULLDUMMY |
SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS |
- SCRIPT_VERIFY_CLEANSTACK;
+ SCRIPT_VERIFY_CLEANSTACK |
+ SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
/** For convenience, standard but not mandatory verify flags. */
static const unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS;
generated by cgit v1.2.3 (git 2.26.2) at 2024-07-16 12:53:30 +0000