def serialize_preimage(
self,
txin_index: int,
*,
bip143_shared_txdigest_fields: BIP143SharedTxDigestFields = None
) -> str:
nVersion = int_to_hex(self.version, 4)
nHashType = int_to_hex(1, 4) # SIGHASH_ALL
nLocktime = int_to_hex(self.locktime, 4)
inputs = self.inputs()
outputs = self.outputs()
txin = inputs[txin_index]
if self.is_segwit_input(txin):
if bip143_shared_txdigest_fields is None:
bip143_shared_txdigest_fields = self._calc_bip143_shared_txdigest_fields(
)
hashPrevouts = bip143_shared_txdigest_fields.hashPrevouts
hashSequence = bip143_shared_txdigest_fields.hashSequence
hashOutputs = bip143_shared_txdigest_fields.hashOutputs
outpoint = self.serialize_outpoint(txin)
preimage_script = self.get_preimage_script(txin)
scriptCode = var_int(len(preimage_script) // 2) + preimage_script
amount = int_to_hex(txin['value'], 8)
nSequence = int_to_hex(txin.get('sequence', 0xffffffff - 1), 4)
preimage = nVersion + hashPrevouts + hashSequence + outpoint + scriptCode + amount + nSequence + hashOutputs + nLocktime + nHashType
else:
txins = var_int(len(inputs)) + ''.join(
self.serialize_input(
txin,
self.get_preimage_script(txin) if txin_index == k else '')
for k, txin in enumerate(inputs))
txouts = var_int(len(outputs)) + ''.join(
self.serialize_output(o) for o in outputs)
preimage = nVersion + txins + txouts + nLocktime + nHashType
return preimage
def serialize_witness(self, txin, estimate_size=False):
_type = txin['type']
if not self.is_segwit_input(txin) and not txin['type'] == 'address':
return '00'
if _type == 'coinbase':
return txin['witness']
witness = txin.get('witness', None)
if witness is None or estimate_size:
if _type == 'address' and estimate_size:
_type = self.guess_txintype_from_address(txin['address'])
pubkeys, sig_list = self.get_siglist(txin, estimate_size)
if _type in ['p2wpkh', 'p2wpkh-p2sh']:
witness = construct_witness([sig_list[0], pubkeys[0]])
elif _type in ['p2wsh', 'p2wsh-p2sh']:
witness_script = multisig_script(pubkeys, txin['num_sig'])
witness = construct_witness([0] + sig_list + [witness_script])
else:
witness = txin.get('witness', '00')
if self.is_txin_complete(txin) or estimate_size:
partial_format_witness_prefix = ''
else:
input_value = int_to_hex(txin['value'], 8)
witness_version = int_to_hex(txin.get('witness_version', 0), 2)
partial_format_witness_prefix = var_int(
0xffffffff) + input_value + witness_version
return partial_format_witness_prefix + witness
def serialize_input(self, txin, script):
# Prev hash and index
s = self.serialize_outpoint(txin)
# Script length, script, sequence
s += var_int(len(script) // 2)
s += script
s += int_to_hex(txin.get('sequence', 0xffffffff - 1), 4)
return s
def serialize_to_network(self, estimate_size=False, witness=True):
self.deserialize()
nVersion = int_to_hex(self.version, 4)
nLocktime = int_to_hex(self.locktime, 4)
inputs = self.inputs()
outputs = self.outputs()
txins = var_int(len(inputs)) + ''.join(
self.serialize_input(txin, self.input_script(txin, estimate_size))
for txin in inputs)
txouts = var_int(len(outputs)) + ''.join(
self.serialize_output(o) for o in outputs)
use_segwit_ser_for_estimate_size = estimate_size and self.is_segwit(
guess_for_address=True)
use_segwit_ser_for_actual_use = not estimate_size and \
(self.is_segwit() or any(txin['type'] == 'address' for txin in inputs))
use_segwit_ser = use_segwit_ser_for_estimate_size or use_segwit_ser_for_actual_use
if witness and use_segwit_ser:
marker = '00'
flag = '01'
witness = ''.join(
self.serialize_witness(x, estimate_size) for x in inputs)
return nVersion + marker + flag + txins + txouts + witness + nLocktime
else:
return nVersion + txins + txouts + nLocktime
def _calc_bip143_shared_txdigest_fields(
self) -> BIP143SharedTxDigestFields:
inputs = self.inputs()
outputs = self.outputs()
hashPrevouts = bh2u(
sha256d(
bfh(''.join(self.serialize_outpoint(txin)
for txin in inputs))))
hashSequence = bh2u(
sha256d(
bfh(''.join(
int_to_hex(txin.get('sequence', 0xffffffff - 1), 4)
for txin in inputs))))
hashOutputs = bh2u(
sha256d(bfh(''.join(self.serialize_output(o) for o in outputs))))
return BIP143SharedTxDigestFields(hashPrevouts=hashPrevouts,
hashSequence=hashSequence,
hashOutputs=hashOutputs)
def serialize_output(cls, output: TxOutput) -> str:
s = int_to_hex(output.value, 8)
script = cls.pay_script(output.type, output.address)
s += var_int(len(script) // 2)
s += script
return s
def serialize_outpoint(self, txin):
return bh2u(bfh(txin['prevout_hash'])[::-1]) + int_to_hex(
txin['prevout_n'], 4)