def get_asm(scriptpubkey):
try:
asm = []
for op in scriptpubkey:
if type(op) == bitcoinlib.core.script.CScriptOp:
asm.append(str(op))
else:
asm.append(op)
except bitcoinlib.core.script.CScriptTruncatedPushDataError:
raise exceptions.DecodeError('invalid pushdata due to truncation')
if not asm:
raise exceptions.DecodeError('empty output')
return asm
def get_checksig(asm):
if len(asm) == 5 and asm[0] == 'OP_DUP' and asm[1] == 'OP_HASH160' and asm[
3] == 'OP_EQUALVERIFY' and asm[4] == 'OP_CHECKSIG':
pubkeyhash = asm[2]
if type(pubkeyhash) == bytes:
return pubkeyhash
raise exceptions.DecodeError('invalid OP_CHECKSIG')
def decode_p2sh_input(asm, p2sh_is_segwit=False):
''' Looks at the scriptSig for the input of the p2sh-encoded data transaction
[signature] [data] [OP_HASH160 ... OP_EQUAL]
'''
pubkey, source, redeem_script_is_valid, found_data = decode_data_redeem_script(
asm[-1], p2sh_is_segwit)
if redeem_script_is_valid:
# this is a signed transaction, so we got {sig[,sig]} {datachunk} {redeemScript}
datachunk = found_data
redeemScript = asm[-1] #asm[-2:]
else:
#print('ASM:', len(asm))
pubkey, source, redeem_script_is_valid, found_data = decode_data_redeem_script(
asm[-1], p2sh_is_segwit)
if not redeem_script_is_valid or len(asm) != 3:
return None, None, None
# this is an unsigned transaction (last is outputScript), so we got [datachunk] [redeemScript] [temporaryOutputScript]
datachunk, redeemScript, _substituteScript = asm
data = datachunk
if data[:len(config.PREFIX)] == config.PREFIX:
data = data[len(config.PREFIX):]
else:
if data == b'':
return source, None, None
raise exceptions.DecodeError('unrecognised P2SH output')
return source, None, data
def get_checkmultisig(asm):
# N‐of‐2
if len(asm) == 5 and asm[3] == 2 and asm[4] == 'OP_CHECKMULTISIG':
pubkeys, signatures_required = asm[1:3], asm[0]
if all([type(pubkey) == bytes for pubkey in pubkeys]):
return pubkeys, signatures_required
# N‐of‐3
if len(asm) == 6 and asm[4] == 3 and asm[5] == 'OP_CHECKMULTISIG':
pubkeys, signatures_required = asm[1:4], asm[0]
if all([type(pubkey) == bytes for pubkey in pubkeys]):
return pubkeys, signatures_required
raise exceptions.DecodeError('invalid OP_CHECKMULTISIG')
def _decode_decodeLUT(data):
(numAddresses, ) = struct.unpack('>H', data[0:2])
if numAddresses == 0:
raise exceptions.DecodeError('address list can\'t be empty')
p = 2
addressList = []
bytesPerAddress = 21
for i in range(0, numAddresses):
addr_raw = data[p:p + bytesPerAddress]
addressList.append(address.unpack(addr_raw))
p += bytesPerAddress
lutNbits = math.ceil(math.log2(numAddresses))
return addressList, lutNbits, data[p:]
def get_asm(scriptpubkey):
# TODO: When is an exception thrown here? Can this `try` block be tighter? Can it be replaced by a conditional?
try:
asm = []
# TODO: This should be `for element in scriptpubkey`.
for op in scriptpubkey:
if type(op) == bitcoinlib.core.script.CScriptOp:
# TODO: `op = element`
asm.append(str(op))
else:
# TODO: `data = element` (?)
asm.append(op)
except bitcoinlib.core.script.CScriptTruncatedPushDataError:
raise exceptions.PushDataDecodeError('invalid pushdata due to truncation')
if not asm:
raise exceptions.DecodeError('empty output')
return asm