mirror of
https://github.com/python-kasa/python-kasa.git
synced 2024-12-22 19:23:34 +00:00
229 lines
8.3 KiB
Python
229 lines
8.3 KiB
Python
"""Module for the XorTransport."""
|
|
import asyncio
|
|
import contextlib
|
|
import errno
|
|
import logging
|
|
import socket
|
|
import struct
|
|
from pprint import pformat as pf
|
|
from typing import Dict, Generator, Optional
|
|
|
|
# When support for cpython older than 3.11 is dropped
|
|
# async_timeout can be replaced with asyncio.timeout
|
|
from async_timeout import timeout as asyncio_timeout
|
|
|
|
from .deviceconfig import DeviceConfig
|
|
from .exceptions import RetryableException, SmartDeviceException
|
|
from .json import loads as json_loads
|
|
from .protocol import BaseTransport
|
|
|
|
_LOGGER = logging.getLogger(__name__)
|
|
_NO_RETRY_ERRORS = {errno.EHOSTDOWN, errno.EHOSTUNREACH, errno.ECONNREFUSED}
|
|
_UNSIGNED_INT_NETWORK_ORDER = struct.Struct(">I")
|
|
|
|
|
|
class XorTransport(BaseTransport):
|
|
"""Implementation of the Xor encryption transport.
|
|
|
|
WIP, currently only to ensure consistent __init__ method signatures
|
|
for protocol classes. Will eventually incorporate the logic from
|
|
TPLinkSmartHomeProtocol to simplify the API and re-use the IotProtocol
|
|
class.
|
|
"""
|
|
|
|
DEFAULT_PORT: int = 9999
|
|
BLOCK_SIZE = 4
|
|
|
|
def __init__(self, *, config: DeviceConfig) -> None:
|
|
super().__init__(config=config)
|
|
self.reader: Optional[asyncio.StreamReader] = None
|
|
self.writer: Optional[asyncio.StreamWriter] = None
|
|
self.query_lock = asyncio.Lock()
|
|
self.loop: Optional[asyncio.AbstractEventLoop] = None
|
|
|
|
@property
|
|
def default_port(self):
|
|
"""Default port for the transport."""
|
|
return self.DEFAULT_PORT
|
|
|
|
@property
|
|
def credentials_hash(self) -> str:
|
|
"""The hashed credentials used by the transport."""
|
|
return ""
|
|
|
|
async def _connect(self, timeout: int) -> None:
|
|
"""Try to connect or reconnect to the device."""
|
|
if self.writer:
|
|
return
|
|
self.reader = self.writer = None
|
|
|
|
task = asyncio.open_connection(self._host, self._port)
|
|
async with asyncio_timeout(timeout):
|
|
self.reader, self.writer = await task
|
|
sock: socket.socket = self.writer.get_extra_info("socket")
|
|
# Ensure our packets get sent without delay as we do all
|
|
# our writes in a single go and we do not want any buffering
|
|
# which would needlessly delay the request or risk overloading
|
|
# the buffer on the device
|
|
sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
|
|
|
|
async def _execute_send(self, request: str) -> Dict:
|
|
"""Execute a query on the device and wait for the response."""
|
|
assert self.writer is not None # noqa: S101
|
|
assert self.reader is not None # noqa: S101
|
|
debug_log = _LOGGER.isEnabledFor(logging.DEBUG)
|
|
if debug_log:
|
|
_LOGGER.debug("%s >> %s", self._host, request)
|
|
self.writer.write(XorEncryption.encrypt(request))
|
|
await self.writer.drain()
|
|
|
|
packed_block_size = await self.reader.readexactly(self.BLOCK_SIZE)
|
|
length = _UNSIGNED_INT_NETWORK_ORDER.unpack(packed_block_size)[0]
|
|
|
|
buffer = await self.reader.readexactly(length)
|
|
response = XorEncryption.decrypt(buffer)
|
|
json_payload = json_loads(response)
|
|
if debug_log:
|
|
_LOGGER.debug("%s << %s", self._host, pf(json_payload))
|
|
|
|
return json_payload
|
|
|
|
async def close(self) -> None:
|
|
"""Close the connection."""
|
|
writer = self.writer
|
|
self.close_without_wait()
|
|
if writer:
|
|
with contextlib.suppress(Exception):
|
|
await writer.wait_closed()
|
|
|
|
def close_without_wait(self) -> None:
|
|
"""Close the connection without waiting for the connection to close."""
|
|
writer = self.writer
|
|
self.reader = self.writer = None
|
|
if writer:
|
|
writer.close()
|
|
|
|
async def reset(self) -> None:
|
|
"""Reset the transport.
|
|
|
|
The transport cannot be reset so we must close instead.
|
|
"""
|
|
await self.close()
|
|
|
|
async def send(self, request: str) -> Dict:
|
|
"""Send a message to the device and return a response."""
|
|
#
|
|
# Most of the time we will already be connected if the device is online
|
|
# and the connect call will do nothing and return right away
|
|
#
|
|
# However, if we get an unrecoverable error (_NO_RETRY_ERRORS and
|
|
# ConnectionRefusedError) we do not want to keep trying since many
|
|
# connection open/close operations in the same time frame can block
|
|
# the event loop.
|
|
# This is especially import when there are multiple tplink devices being polled.
|
|
try:
|
|
await self._connect(self._timeout)
|
|
except ConnectionRefusedError as ex:
|
|
await self.reset()
|
|
raise SmartDeviceException(
|
|
f"Unable to connect to the device: {self._host}:{self._port}: {ex}"
|
|
) from ex
|
|
except OSError as ex:
|
|
await self.reset()
|
|
if ex.errno in _NO_RETRY_ERRORS:
|
|
raise SmartDeviceException(
|
|
f"Unable to connect to the device:"
|
|
f" {self._host}:{self._port}: {ex}"
|
|
) from ex
|
|
else:
|
|
raise RetryableException(
|
|
f"Unable to connect to the device:"
|
|
f" {self._host}:{self._port}: {ex}"
|
|
) from ex
|
|
except Exception as ex:
|
|
await self.reset()
|
|
raise RetryableException(
|
|
f"Unable to connect to the device:" f" {self._host}:{self._port}: {ex}"
|
|
) from ex
|
|
except BaseException:
|
|
# Likely something cancelled the task so we need to close the connection
|
|
# as we are not in an indeterminate state
|
|
self.close_without_wait()
|
|
raise
|
|
|
|
try:
|
|
assert self.reader is not None # noqa: S101
|
|
assert self.writer is not None # noqa: S101
|
|
async with asyncio_timeout(self._timeout):
|
|
return await self._execute_send(request)
|
|
except Exception as ex:
|
|
await self.reset()
|
|
raise RetryableException(
|
|
f"Unable to query the device {self._host}:{self._port}: {ex}"
|
|
) from ex
|
|
except BaseException:
|
|
# Likely something cancelled the task so we need to close the connection
|
|
# as we are not in an indeterminate state
|
|
self.close_without_wait()
|
|
raise
|
|
|
|
def __del__(self) -> None:
|
|
if self.writer and self.loop and self.loop.is_running():
|
|
# Since __del__ will be called when python does
|
|
# garbage collection is can happen in the event loop thread
|
|
# or in another thread so we need to make sure the call to
|
|
# close is called safely with call_soon_threadsafe
|
|
self.loop.call_soon_threadsafe(self.writer.close)
|
|
|
|
|
|
class XorEncryption:
|
|
"""XorEncryption class."""
|
|
|
|
INITIALIZATION_VECTOR = 171
|
|
|
|
@staticmethod
|
|
def _xor_payload(unencrypted: bytes) -> Generator[int, None, None]:
|
|
key = XorEncryption.INITIALIZATION_VECTOR
|
|
for unencryptedbyte in unencrypted:
|
|
key = key ^ unencryptedbyte
|
|
yield key
|
|
|
|
@staticmethod
|
|
def encrypt(request: str) -> bytes:
|
|
"""Encrypt a request for a TP-Link Smart Home Device.
|
|
|
|
:param request: plaintext request data
|
|
:return: ciphertext to be send over wire, in bytes
|
|
"""
|
|
plainbytes = request.encode()
|
|
return _UNSIGNED_INT_NETWORK_ORDER.pack(len(plainbytes)) + bytes(
|
|
XorEncryption._xor_payload(plainbytes)
|
|
)
|
|
|
|
@staticmethod
|
|
def _xor_encrypted_payload(ciphertext: bytes) -> Generator[int, None, None]:
|
|
key = XorEncryption.INITIALIZATION_VECTOR
|
|
for cipherbyte in ciphertext:
|
|
plainbyte = key ^ cipherbyte
|
|
key = cipherbyte
|
|
yield plainbyte
|
|
|
|
@staticmethod
|
|
def decrypt(ciphertext: bytes) -> str:
|
|
"""Decrypt a response of a TP-Link Smart Home Device.
|
|
|
|
:param ciphertext: encrypted response data
|
|
:return: plaintext response
|
|
"""
|
|
return bytes(XorEncryption._xor_encrypted_payload(ciphertext)).decode()
|
|
|
|
|
|
# Try to load the kasa_crypt module and if it is available
|
|
try:
|
|
from kasa_crypt import decrypt, encrypt
|
|
|
|
XorEncryption.decrypt = decrypt # type: ignore[method-assign]
|
|
XorEncryption.encrypt = encrypt # type: ignore[method-assign]
|
|
except ImportError:
|
|
pass
|