def T(hex_script):
invalid_script = CScript(x(hex_script))
self.assertFalse(invalid_script.is_push_only())
def T(serialized: str, b: bool) -> None:
script = CScript(x(serialized))
self.assertEqual(script.is_push_only(), b)
def T(serialized, b):
script = CScript(x(serialized))
self.assertEqual(script.is_push_only(), b)
def VerifyScript(scriptSig: CScript, scriptPubKey: CScript,
txTo: 'bitcointx.core.CTransaction', inIdx: int,
flags: Optional[Union[Tuple[ScriptVerifyFlag_Type, ...],
Set[ScriptVerifyFlag_Type]]] = None,
amount: int = 0, witness: Optional[CScriptWitness] = None
) -> None:
"""Verify a scriptSig satisfies a scriptPubKey
scriptSig - Signature
scriptPubKey - PubKey
txTo - Spending transaction
inIdx - Index of the transaction input containing scriptSig
Raises a ValidationError subclass if the validation fails.
"""
ensure_isinstance(scriptSig, CScript, 'scriptSig')
if not type(scriptSig) == type(scriptPubKey):
raise TypeError(
"scriptSig and scriptPubKey must be of the same script class")
script_class = scriptSig.__class__
if flags is None:
flags = STANDARD_SCRIPT_VERIFY_FLAGS - UNHANDLED_SCRIPT_VERIFY_FLAGS
else:
flags = set(flags) # might be passed as tuple
if flags & UNHANDLED_SCRIPT_VERIFY_FLAGS:
raise VerifyScriptError(
"some of the flags cannot be handled by current code: {}"
.format(script_verify_flags_to_string(flags & UNHANDLED_SCRIPT_VERIFY_FLAGS)))
stack: List[bytes] = []
EvalScript(stack, scriptSig, txTo, inIdx, flags=flags)
if SCRIPT_VERIFY_P2SH in flags:
stackCopy = list(stack)
EvalScript(stack, scriptPubKey, txTo, inIdx, flags=flags)
if len(stack) == 0:
raise VerifyScriptError("scriptPubKey left an empty stack")
if not _CastToBool(stack[-1]):
raise VerifyScriptError("scriptPubKey returned false")
hadWitness = False
if witness is None:
witness = CScriptWitness([])
if SCRIPT_VERIFY_WITNESS in flags and scriptPubKey.is_witness_scriptpubkey():
hadWitness = True
if scriptSig:
raise VerifyScriptError("scriptSig is not empty")
VerifyWitnessProgram(witness,
scriptPubKey.witness_version(),
scriptPubKey.witness_program(),
txTo, inIdx, flags=flags, amount=amount,
script_class=script_class)
# Bypass the cleanstack check at the end. The actual stack is obviously not clean
# for witness programs.
stack = stack[:1]
# Additional validation for spend-to-script-hash transactions
if SCRIPT_VERIFY_P2SH in flags and scriptPubKey.is_p2sh():
if not scriptSig.is_push_only():
raise VerifyScriptError("P2SH scriptSig not is_push_only()")
# restore stack
stack = stackCopy
# stack cannot be empty here, because if it was the
# P2SH HASH <> EQUAL scriptPubKey would be evaluated with
# an empty stack and the EvalScript above would return false.
assert len(stack)
pubKey2 = script_class(stack.pop())
EvalScript(stack, pubKey2, txTo, inIdx, flags=flags)
if not len(stack):
raise VerifyScriptError("P2SH inner scriptPubKey left an empty stack")
if not _CastToBool(stack[-1]):
raise VerifyScriptError("P2SH inner scriptPubKey returned false")
# P2SH witness program
if SCRIPT_VERIFY_WITNESS in flags and pubKey2.is_witness_scriptpubkey():
hadWitness = True
if scriptSig != script_class([pubKey2]):
raise VerifyScriptError("scriptSig is not exactly a single push of the redeemScript")
VerifyWitnessProgram(witness,
pubKey2.witness_version(),
pubKey2.witness_program(),
txTo, inIdx, flags=flags, amount=amount,
script_class=script_class)
# Bypass the cleanstack check at the end. The actual stack is obviously not clean
# for witness programs.
stack = stack[:1]
if SCRIPT_VERIFY_CLEANSTACK in flags:
if SCRIPT_VERIFY_P2SH not in flags:
raise ValueError(
'SCRIPT_VERIFY_CLEANSTACK requires SCRIPT_VERIFY_P2SH')
if len(stack) == 0:
raise VerifyScriptError("scriptPubKey left an empty stack")
elif len(stack) != 1:
raise VerifyScriptError("scriptPubKey left extra items on stack")
if SCRIPT_VERIFY_WITNESS in flags:
# We can't check for correct unexpected witness data if P2SH was off, so require
# that WITNESS implies P2SH. Otherwise, going from WITNESS->P2SH+WITNESS would be
# possible, which is not a softfork.
if SCRIPT_VERIFY_P2SH not in flags:
raise ValueError(
"SCRIPT_VERIFY_WITNESS requires SCRIPT_VERIFY_P2SH")
if not hadWitness and witness:
raise VerifyScriptError("Unexpected witness")
