Midea/packet_builder.py
2023-09-22 18:06:37 +02:00

60 lines
2 KiB
Python

from security import LocalSecurity
import datetime
class PacketBuilder:
def __init__(self, device_id: int, command):
self.command = None
self.security = LocalSecurity()
# aa20ac00000000000003418100ff03ff000200000000000000000000000006f274
# Init the packet with the header data.
self.packet = bytearray([
# 2 bytes - StaicHeader
0x5a, 0x5a,
# 2 bytes - mMessageType
0x01, 0x11,
# 2 bytes - PacketLenght
0x00, 0x00,
# 2 bytes
0x20, 0x00,
# 4 bytes - MessageId
0x00, 0x00, 0x00, 0x00,
# 8 bytes - Date&Time
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
# 6 bytes - mDeviceID
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
# 12 bytes
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
])
self.packet[12:20] = self.packet_time()
self.packet[20:28] = device_id.to_bytes(8, "little")
self.command = command
def finalize(self, msg_type=1):
if msg_type != 1:
self.packet[3] = 0x10
self.packet[6] = 0x7b
else:
self.packet.extend(self.security.aes_encrypt(self.command))
# PacketLenght
self.packet[4:6] = (len(self.packet) + 16).to_bytes(2, "little")
# Append a basic checksum data(16 bytes) to the packet
self.packet.extend(self.encode32(self.packet))
return self.packet
def encode32(self, data: bytearray):
return self.security.encode32_data(data)
@staticmethod
def checksum(data):
return (~ sum(data) + 1) & 0xff
@staticmethod
def packet_time():
t = datetime.datetime.now().strftime("%Y%m%d%H%M%S%f")[
:16]
b = bytearray()
for i in range(0, len(t), 2):
d = int(t[i:i+2])
b.insert(0, d)
return b