LBRY-Vault/electrum/plugins/trustedcoin/legacy_tx_format.py
2019-11-04 22:24:36 +01:00

106 lines
4.3 KiB
Python

# Copyright (C) 2018 The Electrum developers
# Distributed under the MIT software license, see the accompanying
# file LICENCE or http://www.opensource.org/licenses/mit-license.php
import copy
from typing import Union
from electrum import bitcoin
from electrum.bitcoin import push_script, int_to_hex, var_int
from electrum.transaction import (Transaction, PartialTransaction, PartialTxInput,
multisig_script, construct_witness)
from electrum.keystore import BIP32_KeyStore
from electrum.wallet import Multisig_Wallet
ELECTRUM_PARTIAL_TXN_HEADER_MAGIC = b'EPTF\xff'
PARTIAL_FORMAT_VERSION = b'\x00'
NO_SIGNATURE = b'\xff'
def get_xpubkey(keystore: BIP32_KeyStore, c, i) -> str:
def encode_path_int(path_int) -> str:
if path_int < 0xffff:
hex = bitcoin.int_to_hex(path_int, 2)
else:
hex = 'ffff' + bitcoin.int_to_hex(path_int, 4)
return hex
s = ''.join(map(encode_path_int, (c, i)))
return 'ff' + bitcoin.DecodeBase58Check(keystore.xpub).hex() + s
def serialize_tx_in_legacy_format(tx: PartialTransaction, *, wallet: Multisig_Wallet) -> str:
assert isinstance(tx, PartialTransaction)
# copy tx so we don't mutate the input arg
# monkey-patch method of tx instance to change serialization
tx = copy.deepcopy(tx)
def get_siglist(txin: 'PartialTxInput', *, estimate_size=False):
if txin.prevout.is_coinbase():
return [], []
if estimate_size:
try:
pubkey_size = len(txin.pubkeys[0])
except IndexError:
pubkey_size = 33 # guess it is compressed
num_pubkeys = max(1, len(txin.pubkeys))
pk_list = ["00" * pubkey_size] * num_pubkeys
# we assume that signature will be 0x48 bytes long
num_sig = max(txin.num_sig, num_pubkeys)
sig_list = [ "00" * 0x48 ] * num_sig
else:
pk_list = ["" for pk in txin.pubkeys]
for ks in wallet.get_keystores():
my_pubkey, full_path = ks.find_my_pubkey_in_txinout(txin)
x_pubkey = get_xpubkey(ks, full_path[-2], full_path[-1])
pubkey_index = txin.pubkeys.index(my_pubkey)
pk_list[pubkey_index] = x_pubkey
assert all(pk_list)
sig_list = [txin.part_sigs.get(pubkey, NO_SIGNATURE).hex() for pubkey in txin.pubkeys]
return pk_list, sig_list
def input_script(self, txin: PartialTxInput, *, estimate_size=False) -> str:
assert estimate_size is False
pubkeys, sig_list = get_siglist(txin, estimate_size=estimate_size)
script = ''.join(push_script(x) for x in sig_list)
if txin.script_type == 'p2sh':
# put op_0 before script
script = '00' + script
redeem_script = multisig_script(pubkeys, txin.num_sig)
script += push_script(redeem_script)
return script
elif txin.script_type == 'p2wsh':
return ''
raise Exception(f"unexpected type {txin.script_type}")
tx.input_script = input_script.__get__(tx, PartialTransaction)
def serialize_witness(self, txin: PartialTxInput, *, estimate_size=False):
assert estimate_size is False
if txin.witness is not None:
return txin.witness.hex()
if txin.prevout.is_coinbase():
return ''
assert isinstance(txin, PartialTxInput)
if not self.is_segwit_input(txin):
return '00'
pubkeys, sig_list = get_siglist(txin, estimate_size=estimate_size)
if txin.script_type == 'p2wsh':
witness_script = multisig_script(pubkeys, txin.num_sig)
witness = construct_witness([0] + sig_list + [witness_script])
else:
raise Exception(f"unexpected type {txin.script_type}")
if txin.is_complete() or estimate_size:
partial_format_witness_prefix = ''
else:
input_value = int_to_hex(txin.value_sats(), 8)
witness_version = int_to_hex(0, 2)
partial_format_witness_prefix = var_int(0xffffffff) + input_value + witness_version
return partial_format_witness_prefix + witness
tx.serialize_witness = serialize_witness.__get__(tx, PartialTransaction)
buf = ELECTRUM_PARTIAL_TXN_HEADER_MAGIC.hex()
buf += PARTIAL_FORMAT_VERSION.hex()
buf += tx.serialize_to_network()
return buf