Initial work on refactoring pytuya

Still lots of things to improve, but it's a start. Will continue with
receive code.
This commit is contained in:
Pierre Ståhl
2020-09-28 10:21:23 +02:00
committed by rospogrigio
parent 1d2fdfdba9
commit b50cd7bf84

View File

@@ -41,9 +41,11 @@ from hashlib import md5
import json
import logging
import socket
import sys
import time
import binascii
import struct
from collections import namedtuple
from contextlib import contextmanager
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
@@ -52,9 +54,9 @@ version_tuple = (8, 1, 0)
version = version_string = __version__ = "%d.%d.%d" % version_tuple
__author__ = "rospogrigio"
log = logging.getLogger(__name__)
logging.basicConfig() # TODO include function name/line numbers in log
# log.setLevel(level=logging.DEBUG) # Uncomment to Debug
_LOGGER = logging.getLogger(__name__)
TuyaMessage = namedtuple("TuyaMessage", "seqno cmd retcode payload crc")
SET = "set"
STATUS = "status"
@@ -62,7 +64,87 @@ STATUS = "status"
PROTOCOL_VERSION_BYTES_31 = b"3.1"
PROTOCOL_VERSION_BYTES_33 = b"3.3"
IS_PY2 = sys.version_info[0] == 2
PROTOCOL_33_HEADER = PROTOCOL_VERSION_BYTES_33 + 12 * b"\x00"
MESSAGE_HEADER_FMT = ">4I" # 4*uint32: prefix, seqno, cmd, length
MESSAGE_RECV_HEADER_FMT = ">5I" # 4*uint32: prefix, seqno, cmd, length, retcode
MESSAGE_END_FMT = ">2I" # 2*uint32: crc, suffix
PREFIX_VALUE = 0x000055AA
SUFFIX_VALUE = 0x0000AA55
# This is intended to match requests.json payload at
# https://github.com/codetheweb/tuyapi :
# type_0a devices require the 0a command as the status request
# type_0d devices require the 0d command as the status request, and the list of
# dps used set to null in the request payload (see generate_payload method)
# prefix: # Next byte is command byte ("hexByte") some zero padding, then length
# of remaining payload, i.e. command + suffix (unclear if multiple bytes used for
# length, zero padding implies could be more than one byte)
PAYLOAD_DICT = {
"type_0a": {
"status": {"hexByte": 0x0A, "command": {"gwId": "", "devId": ""}},
"set": {"hexByte": 0x07, "command": {"devId": "", "uid": "", "t": ""}},
},
"type_0d": {
"status": {"hexByte": 0x0D, "command": {"devId": "", "uid": "", "t": ""}},
"set": {"hexByte": 0x07, "command": {"devId": "", "uid": "", "t": ""}},
},
}
@contextmanager
def socketcontext(address, port, timeout):
"""Context manager which sets up and tears down socket properly."""
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
s.settimeout(timeout)
s.connect((address, port))
try:
yield s
except Exception:
# This should probably be a warning or error, but since this happens
# every now and the and we do retries on a higher level, use debug level
# to not spam log with errors.
_LOGGER.debug("Failed to connect to %s. Raising Exception.", address)
raise
finally:
s.close()
def pack_message(msg):
"""Pack a TuyaMessage into bytes."""
# Create full message excluding CRC and suffix
buffer = (
struct.pack(
MESSAGE_HEADER_FMT,
PREFIX_VALUE,
msg.seqno,
msg.cmd,
len(msg.payload) + struct.calcsize(MESSAGE_END_FMT),
)
+ msg.payload
)
# Calculate CRC, add it together with suffix
buffer += struct.pack(MESSAGE_END_FMT, binascii.crc32(buffer), SUFFIX_VALUE)
return buffer
def unpack_message(data):
"""Unpack bytes into a TuyaMessage."""
header_len = struct.calcsize(MESSAGE_RECV_HEADER_FMT)
end_len = struct.calcsize(MESSAGE_END_FMT)
_, seqno, cmd, _, retcode = struct.unpack(
MESSAGE_RECV_HEADER_FMT, data[:header_len]
)
payload = data[header_len:-end_len]
crc, _ = struct.unpack(MESSAGE_END_FMT, data[-end_len:])
return TuyaMessage(seqno, cmd, retcode, payload, crc)
class AESCipher:
@@ -77,11 +159,7 @@ class AESCipher:
"""Encrypt data to be sent to device."""
encryptor = self.cipher.encryptor()
crypted_text = encryptor.update(self._pad(raw)) + encryptor.finalize()
if use_base64:
return base64.b64encode(crypted_text)
else:
return crypted_text
return base64.b64encode(crypted_text) if use_base64 else crypted_text
def decrypt(self, enc, use_base64=True):
"""Decrypt data from device."""
@@ -100,57 +178,11 @@ class AESCipher:
return s[: -ord(s[len(s) - 1 :])]
def bin2hex(x, pretty=False):
"""Convert binary data to hex string."""
if pretty:
space = " "
else:
space = ""
if IS_PY2:
result = "".join("%02X%s" % (ord(y), space) for y in x)
else:
result = "".join("%02X%s" % (y, space) for y in x)
return result
def hex2bin(x):
"""Convert hex string to binary."""
if IS_PY2:
return x.decode("hex")
else:
return bytes.fromhex(x)
# This is intended to match requests.json payload at
# https://github.com/codetheweb/tuyapi :
# type_0a devices require the 0a command as the status request
# type_0d devices require the 0d command as the status request, and the list of
# dps used set to null in the request payload (see generate_payload method)
# prefix: # Next byte is command byte ("hexByte") some zero padding, then length
# of remaining payload, i.e. command + suffix (unclear if multiple bytes used for
# length, zero padding implies could be more than one byte)
payload_dict = {
"type_0a": {
"status": {"hexByte": "0a", "command": {"gwId": "", "devId": ""}},
"set": {"hexByte": "07", "command": {"devId": "", "uid": "", "t": ""}},
"prefix": "000055aa00000000000000",
"suffix": "000000000000aa55",
},
"type_0d": {
"status": {"hexByte": "0d", "command": {"devId": "", "uid": "", "t": ""}},
"set": {"hexByte": "07", "command": {"devId": "", "uid": "", "t": ""}},
"prefix": "000055aa00000000000000",
"suffix": "000000000000aa55",
},
}
class TuyaInterface:
"""Represent a Tuya device."""
def __init__(
self, dev_id, address, local_key, protocol_version, connection_timeout=10
self, dev_id, address, local_key, protocol_version, connection_timeout=5
):
"""
Initialize a new TuyaInterface.
@@ -170,51 +202,56 @@ class TuyaInterface:
self.version = protocol_version
self.dev_type = "type_0a"
self.dps_to_request = {}
self.cipher = AESCipher(self.local_key)
self.seqno = 0
self.port = 6668 # default - do not expect caller to pass in
def __repr__(self):
"""Return internal string representation of object."""
return "%r" % ((self.id, self.address),) # FIXME can do better than this
def exchange(self, command, data=None):
"""Send and recive a message, returning response from device."""
_LOGGER.debug("Sending command %s (device type: %s", self.dev_type)
payload = self._generate_payload(command, data)
dev_type = self.dev_type
def _send_receive(self, payload):
"""
Send single buffer `payload` and receive a single buffer.
Args:
payload(bytes): Data to send.
"""
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
s.settimeout(self.connection_timeout)
s.connect((self.address, self.port))
except Exception as e:
print("Failed to connect to %s. Raising Exception." % (self.address))
raise e
try:
with socketcontext(self.address, self.port, self.connection_timeout) as s:
s.send(payload)
except Exception as e:
print("Failed to send payload to %s. Raising Exception." % (self.address))
# s.close()
raise e
try:
data = s.recv(1024)
# print("FIRST: Received %d bytes" % len(data) )
# sometimes the first packet does not contain data (typically 28 bytes):
# need to read again
if len(data) < 40:
time.sleep(0.1)
data = s.recv(1024)
# print("SECOND: Received %d bytes" % len(data) )
except Exception as e:
print("Failed to receive data from %s. Raising Exception." % (self.address))
# s.close()
raise e
s.close()
return data
msg = unpack_message(data)
# TODO: Verify stuff, e.g. CRC sequence number
payload = self._decode_payload(msg.payload)
# Perform a new exchange (once) if we switched device type
if dev_type != self.dev_type:
_LOGGER.debug(
"Re-send %s due to device type change (%s -> %s)",
command,
dev_type,
self.dev_type,
)
return self.exchange(command, data)
return payload
def status(self):
"""Return device status."""
return self.exchange(STATUS)
def set_dps(self, value, dps_index):
"""
Set value (may be any type: bool, int or string) of any dps index.
Args:
dps_index(int): dps index to set
value: new value for the dps index
"""
return self.exchange(SET, {str(dps_index): value})
def detect_available_dps(self):
"""Return which datapoints are supported by the device."""
@@ -223,48 +260,22 @@ class TuyaInterface:
# in the ranges [1-25] and [100-110] need to split the bruteforcing in
# different steps due to request payload limitation (max. length = 255)
detected_dps = {}
ranges = [(2, 11), (11, 21), (21, 31), (100, 111)]
# dps 1 must always be sent, otherwise it might fail in case no dps is found
# in the requested range
self.dps_to_request = {"1": None}
self.add_dps_to_request(range(2, 11))
try:
data = self.status()
except Exception as e:
print("Failed to get status: [{}]".format(e))
raise
detected_dps.update(data["dps"])
for dps_range in ranges:
# dps 1 must always be sent, otherwise it might fail in case no dps is found
# in the requested range
self.dps_to_request = {"1": None}
self.add_dps_to_request(range(*dps_range))
try:
data = self.status()
except Exception as e:
_LOGGER.warning("Failed to get status: [{}]", e)
raise
detected_dps.update(data["dps"])
if self.dev_type == "type_0a":
return detected_dps
self.dps_to_request = {"1": None}
self.add_dps_to_request(range(11, 21))
try:
data = self.status()
except Exception as e:
print("Failed to get status: [{}]".format(e))
raise
detected_dps.update(data["dps"])
self.dps_to_request = {"1": None}
self.add_dps_to_request(range(21, 31))
try:
data = self.status()
except Exception as e:
print("Failed to get status: [{}]".format(e))
raise
detected_dps.update(data["dps"])
self.dps_to_request = {"1": None}
self.add_dps_to_request(range(100, 111))
try:
data = self.status()
except Exception as e:
print("Failed to get status: [{}]".format(e))
raise
detected_dps.update(data["dps"])
# print("DATA IS [{}] detected_dps [{}]".format(data,detected_dps))
if self.dev_type == "type_0a":
return detected_dps
return detected_dps
@@ -275,7 +286,37 @@ class TuyaInterface:
else:
self.dps_to_request.update({str(index): None for index in dps_index})
def generate_payload(self, command, data=None):
def _decode_payload(self, payload):
_LOGGER.debug("decode payload=%r", payload)
if payload.startswith(PROTOCOL_VERSION_BYTES_31):
payload = payload[len(PROTOCOL_VERSION_BYTES_31) :] # remove version header
# remove (what I'm guessing, but not confirmed is) 16-bytes of MD5
# hexdigest of payload
payload = self.cipher.decrypt(payload[16:])
elif self.version == 3.3:
if self.dev_type != "type_0a" or payload.startswith(
PROTOCOL_VERSION_BYTES_33
):
payload = payload[len(PROTOCOL_33_HEADER) :]
payload = self.cipher.decrypt(payload, False)
if "data unvalid" in payload:
self.dev_type = "type_0d"
_LOGGER.debug(
"'data unvalid' error detected: switching to dev_type %r",
self.dev_type,
)
return None
elif not payload.startswith(b"{"):
raise Exception(f"Unexpected payload={payload}")
if not isinstance(payload, str):
payload = payload.decode()
_LOGGER.debug("decrypted result=%r", payload)
return json.loads(payload)
def _generate_payload(self, command, data=None):
"""
Generate the payload to send.
@@ -285,8 +326,9 @@ class TuyaInterface:
data(dict, optional): The data to be send.
This is what will be passed via the 'dps' entry
"""
json_data = payload_dict[self.dev_type][command]["command"]
command_hb = payload_dict[self.dev_type][command]["hexByte"]
cmd_data = PAYLOAD_DICT[self.dev_type][command]
json_data = cmd_data["command"]
command_hb = cmd_data["hexByte"]
if "gwId" in json_data:
json_data["gwId"] = self.id
@@ -301,40 +343,20 @@ class TuyaInterface:
json_data["dps"] = data
if command_hb == "0d":
json_data["dps"] = self.dps_to_request
# log.info('******** COMMAND IS %r', self.dps_to_request)
# Create byte buffer from hex data
json_payload = json.dumps(json_data)
# print(json_payload)
json_payload = json_payload.replace(
" ", ""
) # if spaces are not removed device does not respond!
json_payload = json_payload.encode("utf-8")
log.debug("json_payload=%r", json_payload)
# print('json_payload = ', json_payload, ' cmd = ', command_hb)
payload = json.dumps(json_data).replace(" ", "").encode("utf-8")
_LOGGER.debug("paylod=%r", payload)
if self.version == 3.3:
self.cipher = AESCipher(
self.local_key
) # expect to connect and then disconnect to set new
json_payload = self.cipher.encrypt(json_payload, False)
self.cipher = None
if command_hb != "0a":
payload = self.cipher.encrypt(payload, False)
if command_hb != 0x0A:
# add the 3.3 header
json_payload = (
PROTOCOL_VERSION_BYTES_33
+ b"\0\0\0\0\0\0\0\0\0\0\0\0"
+ json_payload
)
payload = PROTOCOL_33_HEADER + payload
elif command == SET:
# need to encrypt
self.cipher = AESCipher(
self.local_key
) # expect to connect and then disconnect to set new
json_payload = self.cipher.encrypt(json_payload)
payload = self.cipher.encrypt(payload)
preMd5String = (
b"data="
+ json_payload
+ payload
+ b"||lpv="
+ PROTOCOL_VERSION_BYTES_31
+ b"||"
@@ -343,130 +365,16 @@ class TuyaInterface:
m = md5()
m.update(preMd5String)
hexdigest = m.hexdigest()
json_payload = (
payload = (
PROTOCOL_VERSION_BYTES_31
+ hexdigest[8:][:16].encode("latin1")
+ json_payload
+ payload
)
self.cipher = None # expect to connect and then disconnect to set new
postfix_payload = hex2bin(
bin2hex(json_payload) + payload_dict[self.dev_type]["suffix"]
)
assert len(postfix_payload) <= 0xFF
postfix_payload_hex_len = "%x" % len(
postfix_payload
) # TODO this assumes a single byte 0-255 (0x00-0xff)
buffer = (
hex2bin(
payload_dict[self.dev_type]["prefix"]
+ payload_dict[self.dev_type][command]["hexByte"]
+ "000000"
+ postfix_payload_hex_len
)
+ postfix_payload
)
msg = TuyaMessage(self.seqno, command_hb, 0, payload, 0)
self.seqno += 1
return pack_message(msg)
# calc the CRC of everything except where the CRC goes and the suffix
hex_crc = format(binascii.crc32(buffer[:-8]) & 0xFFFFFFFF, "08X")
buffer = buffer[:-8] + hex2bin(hex_crc) + buffer[-4:]
return buffer
def status(self):
"""Return device status."""
log.debug("status() entry (dev_type is %s)", self.dev_type)
# open device, send request, then close connection
payload = self.generate_payload("status")
data = self._send_receive(payload)
log.debug("status received data=%r", data)
result = data[20:-8] # hard coded offsets
if self.dev_type != "type_0a":
result = result[15:]
log.debug("result=%r", result)
# result = data[data.find('{'):data.rfind('}')+1] # naive marker search,
# hope neither { nor } occur in header/footer
# print('result %r' % result)
if result.startswith(b"{"):
# this is the regular expected code path
if not isinstance(result, str):
result = result.decode()
result = json.loads(result)
elif result.startswith(PROTOCOL_VERSION_BYTES_31):
# got an encrypted payload, happens occasionally
# expect resulting json to look similar to:
# {"devId":"ID","dps":{"1":true,"2":0},"t":EPOCH_SECS,"s":3_DIGIT_NUM}
# NOTE dps.2 may or may not be present
result = result[len(PROTOCOL_VERSION_BYTES_31) :] # remove version header
# remove (what I'm guessing, but not confirmed is) 16-bytes of MD5
# hexdigest of payload
result = result[16:]
cipher = AESCipher(self.local_key)
result = cipher.decrypt(result)
print("decrypted result=[{}]".format(result))
log.debug("decrypted result=%r", result)
if not isinstance(result, str):
result = result.decode()
result = json.loads(result)
elif self.version == 3.3:
cipher = AESCipher(self.local_key)
result = cipher.decrypt(result, False)
log.debug("decrypted result=%r", result)
if "data unvalid" in result:
self.dev_type = "type_0d"
log.debug(
"'data unvalid' error detected: switching to dev_type %r",
self.dev_type,
)
return self.status()
if not isinstance(result, str):
result = result.decode()
result = json.loads(result)
else:
log.error("Unexpected status() payload=%r", result)
return result
def set_dps(self, value, dps_index):
"""
Set value (may be any type: bool, int or string) of any dps index.
Args:
dps_index(int): dps index to set
value: new value for the dps index
"""
# open device, send request, then close connection
if isinstance(dps_index, int):
dps_index = str(dps_index) # index and payload is a string
payload = self.generate_payload(SET, {dps_index: value})
data = self._send_receive(payload)
log.debug("set_dps received data=%r", data)
return data
def set_timer(self, num_secs):
"""
Set a timer.
Args:
num_secs(int): Number of seconds
"""
# FIXME / TODO support schemas? Accept timer id number as parameter?
# Dumb heuristic; Query status, pick last device id as that is probably
# the timer
status = self.status()
devices = status["dps"]
devices_numbers = list(devices.keys())
devices_numbers.sort()
dps_id = devices_numbers[-1]
payload = self.generate_payload(SET, {dps_id: num_secs})
data = self._send_receive(payload)
log.debug("set_timer received data=%r", data)
return data
def __repr__(self):
"""Return internal string representation of object."""
return "%r" % ((self.id, self.address),) # FIXME can do better than this