def verify_txi(tx, txi, idx, testnet=False):
prev_tx = fetch(txi["txid"], testnet)
lock_script = prev_tx["txos"][txi["idx"]]["script"]
# check if p2sh-p2wpkh or p2sh-p2wsh, p2sh_pattern = [OP_HASH160(0xa9) <hash:20bytes> OP_EQUAL(0x87)]
if len(lock_script) == 3 and lock_script[0] == 0xa9 and \
type(lock_script[1]) == bytes and len(lock_script[1]) == 20 and lock_script[2] == 0x87:
# the last cmd has to be the redeem_script
raw_redeem_script = txi["script"][-1]
# encode_varint로 변환해야 하는것 아닌가? 원소사이즈는 max 520bytes
# 확인해보니 (지미송)코드에 문제 발견
# script.parse에서도 length = util.read_varint(s)로 읽고 있음.
# 그래서 encode_varint로 변경
# 인코딩: https://github.com/jimmysong/programmingbitcoin/blob/2a6558263923214320bbdeb10826464fe24ef540/code-ch13/tx.py#L313
# 디코딩: https://github.com/jimmysong/programmingbitcoin/blob/2a6558263923214320bbdeb10826464fe24ef540/code-ch13/script.py#L78
# raw_redeem_script = util.int_to_little_endian(len(raw_redeem_script), 1) + raw_redeem_script
raw_redeem_script = util.encode_varint(
len(raw_redeem_script)) + raw_redeem_script
_, redeem_script = script.parse(
BytesIO(raw_redeem_script)) # (length, script)
if script.is_p2wpkh(redeem_script):
z = sig_hash_bip143(prev_tx,
tx,
txi,
redeem_script=redeem_script,
witness_script=None,
testnet=testnet)
witness = txi["wits"]
elif script.is_p2wsh(redeem_script):
raw_witness_script = txi["wits"][-1] # wits:[,,,witness_script]
raw_witness_script = util.encode_varint(
len(raw_witness_script)) + raw_witness_script
_, witness_script = script.parse(BytesIO(raw_witness_script))
z = sig_hash_bip143(prev_tx,
tx,
txi,
witness_script=witness_script)
witness = txi["wits"]
else:
z = sig_hash(tx, idx, redeem_script)
witness = None
else: # p2wpkh or p2wsh or ...
if script.is_p2wpkh(lock_script):
z = sig_hash_bip143(prev_tx, tx, txi)
witness = txi["wits"]
elif script.is_p2wsh(lock_script):
raw_witness_script = txi["wits"][-1]
raw_witness_script = util.encode_varint(
len(raw_witness_script)) + raw_witness_script
_, witness_script = script.parse(BytesIO(raw_witness_script))
z = sig_hash_bip143(prev_tx,
tx,
txi,
witness_script=witness_script)
witness = txi["wits"]
else:
z = sig_hash(tx, idx, lock_script)
witness = None
commands = txi["script"] + lock_script
return script.evaluate(commands, z, witness)
def serialize_legacy(tx):
result = util.int_to_little_endian(tx["version"], 4)
result += util.encode_varint(tx["txi.count"])
for txi in tx["txis"]:
result += serialize_txi(txi)
result += util.encode_varint(tx["txo.count"])
for txo in tx["txos"]:
result += serialize_txo(txo)
result += util.int_to_little_endian(tx["locktime"], 4)
return result
def serialize_version(payload):
"""Serialize this message to send over the network"""
# version is 4 bytes little endian
result = util.int_to_little_endian(payload['version'], 4)
# services is 8 bytes little endian
result += util.int_to_little_endian(payload['services'], 8)
# timestamp is 8 bytes little endian
result += util.int_to_little_endian(payload['timestamp'], 8)
# receiver services is 8 bytes little endian
result += util.int_to_little_endian(payload['receiver_services'], 8)
# IPV4 is 10 00 bytes and 2 ff bytes then receiver ip
result += b'\x00' * 10 + b'\xff\xff' + payload['receiver_ip']
# receiver port is 2 bytes, big endian
result += payload['receiver_port'].to_bytes(2, 'big')
# sender services is 8 bytes little endian
result += util.int_to_little_endian(payload['sender_services'], 8)
# IPV4 is 10 00 bytes and 2 ff bytes then sender ip
result += b'\x00' * 10 + b'\xff\xff' + payload['sender_ip']
# sender port is 2 bytes, big endian
result += payload['sender_port'].to_bytes(2, 'big')
# nonce should be 8 bytes
result += payload['nonce']
# useragent is a variable string, so varint first
result += util.encode_varint(len(payload['user_agent']))
result += payload['user_agent']
# latest block is 4 bytes little endian
result += util.int_to_little_endian(payload['latest_block'], 4)
# relay is 00 if false, 01 if true
if payload['relay']:
result += b'\x01'
else:
result += b'\x00'
return result
def serialize_segwit(tx):
result = util.int_to_little_endian(tx["version"], 4)
result += tx["mark"]
result += tx["flag"]
result += util.encode_varint(tx["txi.count"])
for txi in tx["txis"]:
result += serialize_txi(txi)
result += util.encode_varint(tx["txo.count"])
for txo in tx["txos"]:
result += serialize_txo(txo)
for txi in tx["txis"]:
result += util.int_to_little_endian(len(txi["wits"]), 1)
for item in txi["wits"]:
if type(item) == int:
result += util.int_to_little_endian(item, 1)
else:
result += util.encode_varint(len(item)) + item
result += util.int_to_little_endian(tx["locktime"], 4)
return result
def serialize_getdata(payload):
# start with the number of items as a varint
result = util.encode_varint(len(payload['data']))
# loop through each tuple (data_type, identifier) in self.data
for data_type, identifier in payload['data']:
# data type is 4 bytes Little-Endian
result += util.int_to_little_endian(data_type, 4)
# identifier needs to be in Little-Endian
result += identifier[::-1]
return result
def serialize_getheaders(payload):
"""Serialize this message to send over the network"""
# protocol version is 4 bytes little-endian
result = util.int_to_little_endian(payload['version'], 4)
# number of hashes is a varint
result += util.encode_varint(payload['num_hashes'])
# start block is in little-endian
result += payload['start_block'][::-1]
# end block is also in little-endian
result += payload['end_block'][::-1]
return result
def serialize_filterload(payload, flag=1):
"""Return the filterload message"""
# start the payload with the size of the filter in bytes
result = util.encode_varint(payload['size'])
# next add the bit field using self.filter_bytes()
result += bloomfilter.bit_field_to_bytes(payload['bit_field'])
# function count is 4 bytes little endian
result += util.int_to_little_endian(payload['function_count'], 4)
# tweak is 4 bytes little endian
result += util.int_to_little_endian(payload['tweak'], 4)
# flag is 1 byte little endian
result += util.int_to_little_endian(flag, 1)
return result
def serialize(script):
result = b'' # initialize what we'll send back
for token in script: # go through each token
if type(token) == int: # if the token is an integer, it's an opcode
result += util.int_to_little_endian(token, 1)
else: # otherwise, this is an element
length = len(token) # get the length in bytes
if length < 75: # turn the length into a single byte integer
result += util.int_to_little_endian(length, 1)
elif 75 < length < 0x100: # 76 is pushdata1
result += util.int_to_little_endian(76, 1)
result += util.int_to_little_endian(length, 1)
elif 0x100 <= length <= 520: # 77 is pushdata2
result += util.int_to_little_endian(77, 1)
result += util.int_to_little_endian(length, 2)
else:
raise ValueError('too long an token')
result += token
total = len(result)
return util.encode_varint(total) + result
def evaluate(commands, z, witness):
cmds = commands[:] # create a copy as we may need to add to this list if we have a redeem_script
stack = []
altstack = []
while len(cmds) > 0:
cmd = cmds.pop(0)
if type(cmd) == int:
# do what the opcode says
operation = op.OP_CODE_FUNCTIONS[cmd]
if cmd in (99, 100):
# op_if/op_notif require the cmds array
if not operation(stack, cmds):
LOGGER.info('bad op: {}'.format(op.OP_CODE_NAMES[cmd]))
return False
elif cmd in (107, 108):
# op_toaltstack/op_fromaltstack require the altstack
if not operation(stack, altstack):
LOGGER.info('bad op: {}'.format(op.OP_CODE_NAMES[cmd]))
return False
elif cmd in (172, 173, 174, 175):
# these are signing operations, they need a sig_hash
# to check against
if not operation(stack, z):
LOGGER.info('bad op: {}'.format(op.OP_CODE_NAMES[cmd]))
return False
else:
if not operation(stack):
LOGGER.info('bad op: {}'.format(op.OP_CODE_NAMES[cmd]))
return False
else:
# add the cmd to the stack
stack.append(cmd)
# p2sh rule. if the next three cmds are:
# OP_HASH160 <20 byte hash> OP_EQUAL this is the RedeemScript
# OP_HASH160 == 0xa9 and OP_EQUAL == 0x87
if len(cmds) == 3 and cmds[0] == 0xa9 \
and type(cmds[1]) == bytes and len(cmds[1]) == 20 \
and cmds[2] == 0x87:
# we execute the next three opcodes
cmds.pop()
h160 = cmds.pop()
cmds.pop()
if not op.op_hash160(stack):
return False
stack.append(h160)
if not op.op_equal(stack):
return False
# final result should be a 1
if not op.op_verify(stack):
LOGGER.info('bad p2sh h160')
return False
raw_redeem_script = util.encode_varint(len(cmd)) + cmd
_, redeem_script = parse(BytesIO(raw_redeem_script))
cmds.extend(redeem_script)
# witness program version 0 rule. if stack cmds are [0 <20 byte hash>] this is p2wpkh
if len(stack) == 2 and stack[0] == b'' and len(stack[1]) == 20:
h160 = stack.pop()
stack.pop()
cmds.extend(witness)
cmds.extend(p2pkh_script(h160))
# witness program version 0 rule. if stack cmds are:[0 <32 byte hash>] this is p2wsh
if len(stack) == 2 and stack[0] == b'' and len(stack[1]) == 32:
s256 = stack.pop()
stack.pop()
cmds.extend(witness[:-1])
raw_witness_script = witness[-1]
if s256 != util.sha256(raw_witness_script):
print('bad sha256 {} vs {}'.format(
s256.hex(),
util.sha256(raw_witness_script).hex()))
return False
stream = BytesIO(
util.encode_varint(len(raw_witness_script)) +
raw_witness_script)
cmds.extend(parse(stream))
if len(stack) == 0:
return False
if stack.pop() == b'':
return False
return True
