def to_bytes(self):
return b''.join((
pack_le_int32(self.version),
pack_list(self.inputs, XTxInput.to_bytes),
pack_list(self.outputs, XTxOutput.to_bytes),
pack_le_uint32(self.locktime),
))
def get_preimage(tx, input_index, utxo_value, utxo_script, sighash_flag=None):
if not sighash_flag:
sighash_flag = SigHash(SigHash.ALL | SigHash.FORKID)
txin = tx.inputs[input_index]
hash_prevouts = hash_sequence = hash_outputs = bitcoinx.consts.ZERO
sighash_not_single_none = sighash_flag.base not in (SigHash.SINGLE, SigHash.NONE)
if not sighash_flag.anyone_can_pay:
hash_prevouts = tx._hash_prevouts()
if sighash_not_single_none:
hash_sequence = tx._hash_sequence()
if sighash_not_single_none:
hash_outputs = tx._hash_outputs()
elif (sighash_flag.base == SigHash.SINGLE and input_index < len(tx.outputs)):
hash_outputs = double_sha256(tx.outputs[input_index].to_bytes())
preimage = b''.join((
pack_le_int32(tx.version),
hash_prevouts,
hash_sequence,
txin.to_bytes_for_signature(utxo_value, utxo_script),
hash_outputs,
pack_le_uint32(tx.locktime),
pack_le_uint32(sighash_flag),
))
return preimage