def _read_length(r: utils.BufferReader, aux: int) -> int:
if aux < _CBOR_UINT8_FOLLOWS:
return aux
elif aux == _CBOR_UINT8_FOLLOWS:
return r.get()
elif aux == _CBOR_UINT16_FOLLOWS:
return readers.read_uint16_be(r)
elif aux == _CBOR_UINT32_FOLLOWS:
return readers.read_uint32_be(r)
elif aux == _CBOR_UINT64_FOLLOWS:
return readers.read_uint64_be(r)
else:
raise NotImplementedError("Length %d not suppported" % aux)
def check_tx_params_size(params: bytes) -> None:
try:
r = BufferReader(params)
tag = r.get()
if tag == EP_TAG_NAMED:
n = r.get()
r.read(n)
elif tag > 4:
raise wire.DataError("Unknown entrypoint tag")
n = read_uint32_be(r)
ensure(r.remaining_count() == n)
except (AssertionError, EOFError):
raise wire.DataError("Invalid transaction parameters")
def read_op_push(r: BufferReader) -> int:
prefix = r.get()
if prefix < 0x4C:
n = prefix
elif prefix == 0x4C:
n = r.get()
elif prefix == 0x4D:
n = r.get()
n += r.get() << 8
elif prefix == 0x4E:
n = r.get()
n += r.get() << 8
n += r.get() << 16
n += r.get() << 24
else:
raise ValueError
return n
def read_int(r: BufferReader) -> memoryview:
if r.get() != 0x02:
raise ValueError
n = read_length(r)
if n == 0:
raise ValueError
if r.peek() & 0x80:
raise ValueError # negative integer
if r.peek() == 0x00 and n > 1:
r.get()
n -= 1
if r.peek() & 0x80 == 0x00:
raise ValueError # excessive zero-padding
if r.peek() == 0x00:
raise ValueError # excessive zero-padding
return r.read_memoryview(n)
def decode_int(r: BufferReader) -> bytes:
if r.get() != 0x02:
raise ValueError
n = decode_length(r)
if n == 0:
raise ValueError
if r.peek() & 0x80:
raise ValueError # negative integer
if r.peek() == 0x00 and n > 1:
r.get()
n -= 1
if r.peek() & 0x80 == 0x00:
raise ValueError # excessive zero-padding
if r.peek() == 0x00:
raise ValueError # excessive zero-padding
return r.read(n)
def read_bitcoin_varint(r: BufferReader) -> int:
prefix = r.get()
if prefix < 253:
n = prefix
elif prefix == 253:
n = r.get()
n += r.get() << 8
elif prefix == 254:
n = r.get()
n += r.get() << 8
n += r.get() << 16
n += r.get() << 24
else:
raise ValueError
return n
def load_message(msg_type, buffer: bytearray) -> protobuf.MessageType:
return protobuf.load_message(BufferReader(buffer), msg_type)
def read_uint16_be(r: BufferReader) -> int:
n = r.get()
return (n << 8) + r.get()
def load_uvarint(data: bytes) -> int:
reader = BufferReader(data)
return protobuf.load_uvarint(reader)
def read_memoryview_prefixed(r: BufferReader) -> memoryview:
n = read_bitcoin_varint(r)
return r.read_memoryview(n)
def read_bip322_signature_proof(r: utils.BufferReader) -> Tuple[bytes, bytes]:
script_sig = read_bytes_prefixed(r)
witness = r.read()
return script_sig, witness
def _cbor_decode(r: utils.BufferReader) -> Value:
fb = r.get()
fb_type = fb & _CBOR_TYPE_MASK
fb_aux = fb & _CBOR_INFO_BITS
if fb_type == _CBOR_UNSIGNED_INT:
return _read_length(r, fb_aux)
elif fb_type == _CBOR_NEGATIVE_INT:
val = _read_length(r, fb_aux)
return -1 - val
elif fb_type == _CBOR_BYTE_STRING:
ln = _read_length(r, fb_aux)
return r.read(ln)
elif fb_type == _CBOR_TEXT_STRING:
ln = _read_length(r, fb_aux)
return r.read(ln).decode()
elif fb_type == _CBOR_ARRAY:
if fb_aux == _CBOR_VAR_FOLLOWS:
res: Value = []
while True:
item = _cbor_decode(r)
if item == _CBOR_PRIMITIVE + _CBOR_BREAK:
break
res.append(item)
return res
else:
ln = _read_length(r, fb_aux)
res = []
for _ in range(ln):
item = _cbor_decode(r)
res.append(item)
return res
elif fb_type == _CBOR_MAP:
res = {}
if fb_aux == _CBOR_VAR_FOLLOWS:
while True:
key = _cbor_decode(r)
if key in res:
raise ValueError
if key == _CBOR_PRIMITIVE + _CBOR_BREAK:
break
value = _cbor_decode(r)
res[key] = value
else:
ln = _read_length(r, fb_aux)
for _ in range(ln):
key = _cbor_decode(r)
if key in res:
raise ValueError
value = _cbor_decode(r)
res[key] = value
return res
elif fb_type == _CBOR_TAG:
val = _read_length(r, fb_aux)
item = _cbor_decode(r)
if val == _CBOR_RAW_TAG: # only tag 24 (0x18) is supported
return item
else:
return Tagged(val, item)
elif fb_type == _CBOR_PRIMITIVE:
if fb_aux == _CBOR_FALSE:
return False
elif fb_aux == _CBOR_TRUE:
return True
elif fb_aux == _CBOR_NULL:
return None
elif fb_aux == _CBOR_BREAK:
return fb
else:
raise NotImplementedError
else:
if __debug__:
log.debug(__name__, "not implemented (decode): %s", fb)
raise NotImplementedError
def read_compact_size(r: BufferReader) -> int:
prefix = r.get()
if prefix < 253:
n = prefix
elif prefix == 253:
n = r.get()
n += r.get() << 8
elif prefix == 254:
n = r.get()
n += r.get() << 8
n += r.get() << 16
n += r.get() << 24
elif prefix == 255:
n = r.get()
n += r.get() << 8
n += r.get() << 16
n += r.get() << 24
n += r.get() << 32
n += r.get() << 40
n += r.get() << 48
n += r.get() << 56
else:
raise ValueError
return n
def read_uint64_be(r: BufferReader) -> int:
n = r.get()
for _ in range(7):
n = (n << 8) + r.get()
return n
def read_uint32_be(r: BufferReader) -> int:
n = r.get() << 24
n += r.get() << 16
n += r.get() << 8
n += r.get()
return n
def read_memoryview_prefixed(r: BufferReader) -> memoryview:
n = read_compact_size(r)
return r.read_memoryview(n)
def read_bytes_prefixed(r: BufferReader) -> bytes:
n = read_bitcoin_varint(r)
return r.read(n)
def read_bip322_signature_proof(
r: utils.BufferReader) -> tuple[memoryview, memoryview]:
script_sig = read_memoryview_prefixed(r)
witness = r.read_memoryview()
return script_sig, witness
