Update encryption for new firmware/devices

[Enzo-Matrix]

The pyHS100 has a working encrypt/decrypt function in protocol.py which should be used to fixed new firmware/devices issue. See below for the code I literally copied from that project:

# Encryption and Decryption of TP-Link Smart Home Protocol
# XOR Autokey Cipher with starting key = 171
def encrypt(request: str) -> bytearray:
        key = 171
        plainbytes = request.encode()
        buffer = bytearray(struct.pack(">I", len(plainbytes)))

        for plainbyte in plainbytes:
                cipherbyte = key ^ plainbyte
                key = cipherbyte
                buffer.append(cipherbyte)

        return bytes(buffer)

def decrypt(ciphertext: bytes) -> str:
        key = 171 
        buffer = []

        for cipherbyte in ciphertext:
                plainbyte = key ^ cipherbyte
                key = cipherbyte
                buffer.append(plainbyte)

                plaintext = bytes(buffer)

        return plaintext.decode()

[sylvandb]

other than being python3, that looks functionally equivalent to me. in what respect is the softScheck version incorrect?

[Enzo-Matrix]

I don't understand python well enough to say why. But I was not getting any returned result when ran against HS210 dinner.

Looks like I was running a very old version of tplink-smartplug. The blog shows the code was update back in July 2018.