python-kasa/pyHS100/protocol.py
2018-01-17 22:03:19 +01:00

119 lines
3.6 KiB
Python

import json
import socket
import struct
import logging
from typing import Any, Dict, Union
_LOGGER = logging.getLogger(__name__)
class TPLinkSmartHomeProtocol:
"""
Implementation of the TP-Link Smart Home Protocol
Encryption/Decryption methods based on the works of
Lubomir Stroetmann and Tobias Esser
https://www.softscheck.com/en/reverse-engineering-tp-link-hs110/
https://github.com/softScheck/tplink-smartplug/
which are licensed under the Apache License, Version 2.0
http://www.apache.org/licenses/LICENSE-2.0
"""
INITIALIZATION_VECTOR = 171
DEFAULT_PORT = 9999
DEFAULT_TIMEOUT = 5
@staticmethod
def query(host: str,
request: Union[str, Dict],
port: int = DEFAULT_PORT) -> Any:
"""
Request information from a TP-Link SmartHome Device and return the
response.
:param str host: host name or ip address of the device
:param int port: port on the device (default: 9999)
:param request: command to send to the device (can be either dict or
json string)
:return:
"""
if isinstance(request, dict):
request = json.dumps(request)
timeout = TPLinkSmartHomeProtocol.DEFAULT_TIMEOUT
try:
sock = socket.create_connection((host, port), timeout)
_LOGGER.debug("> (%i) %s", len(request), request)
sock.send(TPLinkSmartHomeProtocol.encrypt(request))
buffer = bytes()
# Some devices send responses with a length header of 0 and
# terminate with a zero size chunk. Others send the length and
# will hang if we attempt to read more data.
length = -1
while True:
chunk = sock.recv(4096)
if length == -1:
length = struct.unpack(">I", chunk[0:4])[0]
buffer += chunk
if (length > 0 and len(buffer) >= length + 4) or not chunk:
break
finally:
try:
sock.shutdown(socket.SHUT_RDWR)
except OSError:
# OSX raises OSError when shutdown() gets called on a closed
# socket. We ignore it here as the data has already been read
# into the buffer at this point.
pass
finally:
sock.close()
response = TPLinkSmartHomeProtocol.decrypt(buffer[4:])
_LOGGER.debug("< (%i) %s", len(response), response)
return json.loads(response)
@staticmethod
def encrypt(request: str) -> bytearray:
"""
Encrypt a request for a TP-Link Smart Home Device.
:param request: plaintext request data
:return: ciphertext request
"""
key = TPLinkSmartHomeProtocol.INITIALIZATION_VECTOR
buffer = bytearray(struct.pack(">I", len(request)))
for char in request:
cipher = key ^ ord(char)
key = cipher
buffer.append(cipher)
return buffer
@staticmethod
def decrypt(ciphertext: bytes) -> str:
"""
Decrypt a response of a TP-Link Smart Home Device.
:param ciphertext: encrypted response data
:return: plaintext response
"""
key = TPLinkSmartHomeProtocol.INITIALIZATION_VECTOR
buffer = []
ciphertext_str = ciphertext.decode('latin-1')
for char in ciphertext_str:
plain = key ^ ord(char)
key = ord(char)
buffer.append(chr(plain))
plaintext = ''.join(buffer)
return plaintext