def serialize_unit(unit):
if isinstance(unit, Opcode):
return convert.int_to_byte(unit.value)
if isinstance(unit, bytes):
if len(unit) <= 75:
return convert.int_to_byte(len(unit)) + unit
elif len(unit) < 256:
return convert.int_to_byte(76) + convert.int_to_byte(len(unit))+unit
elif len(unit) < 65536:
return convert.int_to_byte(77) + convert.int_to_bytes_le(len(unit), 2) + unit
else:
return convert.int_to_byte(78) + convert.int_to_bytes_le(len(unit), 4) + unit
raise Exception('Bad script unit type')
def sighash(tx, i, prevScript, hashtype = SIGHASH_ALL):
assert isinstance(tx, dict)
i = int(i)
newtx = copy.deepcopy(tx)
for inp in newtx["ins"]:
inp["script"] = b''
s = script.deserialize(prevScript)
s = [x for x in s if x is not script.Opcode.OP_CODESEPARATOR]
newtx["ins"][i]["script"] = script.serialize(s)
if hashtype & 0x1f == SIGHASH_NONE:
newtx["outs"] = []
for inp in range(len(newtx['ins'])):
if inp != i:
newtx['ins'][inp]['sequence'] = 0
elif hashtype & 0x1f == SIGHASH_SINGLE:
newtx["outs"] = newtx["outs"][:i+1]
for out in range(i):
newtx["outs"][out]['value'] = 2**64 - 1
newtx["outs"][out]['script'] = b''
for inp in range(len(newtx['ins'])):
if inp != i:
newtx['ins'][inp]['sequence'] = 0
if hashtype & SIGHASH_ANYONECANPAY != 0:
newtx["ins"] = [newtx["ins"][i]]
hashbytes = convert.int_to_bytes_le(hashtype, 4)
return hashes.hash256(serialize(newtx) + hashbytes)
def serialize(txobj):
o = bytearray()
o += convert.int_to_bytes_le(txobj["version"], 4)
o += encode_var_int(len(txobj["ins"]))
for inp in txobj["ins"]:
o += inp["outpoint"]["hash"][::-1]
o += convert.int_to_bytes_le(inp["outpoint"]["index"], 4)
o += encode_var_int(len(inp["script"])) + inp["script"]
o += convert.int_to_bytes_le(inp["sequence"], 4)
o += encode_var_int(len(txobj["outs"]))
for out in txobj["outs"]:
o += convert.int_to_bytes_le(out["value"], 8)
o += encode_var_int(len(out["script"])) + out["script"]
o += convert.int_to_bytes_le(txobj["locktime"], 4)
return bytes(o)
def encode_var_int(x):
x = int(x)
if x < 253: return convert.int_to_byte(x)
elif x < 65536: return convert.int_to_byte(253) + convert.int_to_bytes_le(x, 2)
elif x < 4294967296: return convert.int_to_byte(254) + convert.int_to_bytes_le(x, 4)
else: return convert.int_to_byte(255) + convert.int_to_bytes_le(x, 8)
