woof/pyezviz/cas.py

"""Ezviz CAS API Functions."""

import random
import socket
import ssl
from io import BytesIO
from itertools import cycle

import xmltodict
from Crypto.Cipher import AES
from pyezviz.constants import FEATURE_CODE, XOR_KEY
from pyezviz.exceptions import InvalidHost


def xor_enc_dec(msg, xor_key=XOR_KEY):
    """Xor encodes camera serial"""
    with BytesIO(msg) as stream:
        xor_msg = bytes(a ^ b for a, b in zip(stream.read(), cycle(xor_key)))
    return xor_msg


class EzvizCAS:
    """Ezviz CAS server client."""

    def __init__(self, token):
        """Initialize the client object."""
        self._session = None
        self._token = token or {
            "session_id": None,
            "rf_session_id": None,
            "username": None,
            "api_url": "apiieu.ezvizlife.com",
        }
        self._service_urls = token["service_urls"]

    def cas_get_encryption(self, devserial):
        """Fetch encryption code from ezviz cas server"""

        # Random hex 64 characters long.
        rand_hex = random.randrange(10 ** 80)
        rand_hex = "%064x" % rand_hex
        rand_hex = rand_hex[:64]

        payload = (
            f"\x9e\xba\xac\xe9\x01\x00\x00\x00\x00\x00"
            f"\x00\x02"  # Check or order?
            f"\x00\x00\x00\x00\x00\x00 "
            f"\x01"  # Check or order?
            f"\x00\x00\x00\x00\x00\x00\x02\t\x00\x00\x00\x00"
            f'<?xml version="1.0" encoding="utf-8"?>\n<Request>\n\t'
            f'<ClientID>{self._token["session_id"]}</ClientID>'
            f"\n\t<Sign>{FEATURE_CODE}</Sign>\n\t"
            f"<DevSerial>{devserial}</DevSerial>"
            f"\n\t<ClientType>0</ClientType>\n</Request>\n"
        ).encode("latin1")

        payload_end_padding = rand_hex.encode("latin1")

        context = ssl.SSLContext(cert_reqs=ssl.CERT_NONE)

        # Create a TCP/IP socket
        my_socket = socket.create_connection(
            (self._service_urls["sysConf"][15], self._service_urls["sysConf"][16])
        )
        my_socket = context.wrap_socket(
            my_socket, server_hostname=self._service_urls["sysConf"][15]
        )

        # Get CAS Encryption Key
        try:
            my_socket.send(payload + payload_end_padding)
            response = my_socket.recv(1024)
            print(f"Get Encryption Key: {response}")

        except (socket.gaierror, ConnectionRefusedError) as err:
            raise InvalidHost("Invalid IP or Hostname") from err

        finally:
            my_socket.close()

        # Trim header, tail and convert xml to dict.
        response = response[32::]
        response = response[:-32:]
        response = xmltodict.parse(response)

        return response

    def set_camera_defence_state(self, serial, enable=1):
        """Enable alarm notifications."""

        # Random hex 64 characters long.
        rand_hex = random.randrange(10 ** 80)
        rand_hex = "%064x" % rand_hex
        rand_hex = rand_hex[:64]

        payload = (
            f"\x9e\xba\xac\xe9\x01\x00\x00\x00\x00\x00"
            f"\x00\x14"  # Check or order?
            f"\x00\x00\x00\x00\x00\x00 "
            f"\x05"
            f"\x00\x00\x00\x00\x00\x00\x02\xd0\x00\x00\x01\xe0"
            f'<?xml version="1.0" encoding="utf-8"?>\n<Request>\n\t'
            f'<Verify ClientSession="{self._token["session_id"]}" '
            f'ToDevice="{serial}" ClientType="0" />\n\t'
            f'<Message Length="240" />\n</Request>\n'
            f"\x9e\xba\xac\xe9\x01\x00\x00\x00\x00\x00"
            f"\x00\x13"
            f"\x00\x00\x00\x00\x00\x000\x0f\xff\xff\xff\xff"
            f"\x00\x00\x00\xb0\x00\x00\x00\x00"
        ).encode("latin1")

        payload_end_padding = rand_hex.encode("latin1")

        # xor camera serial
        xor_cam_serial = xor_enc_dec(serial.encode("latin1"))

        defence_msg_string = (
            f'{xor_cam_serial.decode()}2+,*xdv.0" '
            f'encoding="utf-8"?>\n'
            f"<Request>\n"
            f"\t<OperationCode>ABCDEFG</OperationCode>\n"
            f'\t<Defence Type="Global" Status="{enable}" Actor="V" Channel="0" />\n'
            f"</Request>\n"
            f"\x10\x10\x10\x10\x10\x10\x10\x10\x10\x10\x10\x10\x10\x10\x10\x10"
        ).encode("latin1")

        context = ssl.SSLContext(cert_reqs=ssl.CERT_NONE)

        # Create a TCP/IP socket
        my_socket = socket.create_connection(
            (self._service_urls["sysConf"][15], self._service_urls["sysConf"][16])
        )
        my_socket = context.wrap_socket(
            my_socket, server_hostname=self._service_urls["sysConf"][15]
        )

        cas_client = self.cas_get_encryption(serial)

        aes_key = cas_client["Response"]["Session"]["@Key"].encode("latin1")
        iv_value = (
            f"{serial}{cas_client['Response']['Session']['@OperationCode']}".encode(
                "latin1"
            )
        )

        # Message encryption
        cipher = AES.new(aes_key, AES.MODE_CBC, iv_value)

        try:
            defence_msg_string = cipher.encrypt(defence_msg_string)
            my_socket.send(payload + defence_msg_string + payload_end_padding)
            print(f"Set camera response: {my_socket.recv()}")

        except (socket.gaierror, ConnectionRefusedError) as err:
            raise InvalidHost("Invalid IP or Hostname") from err

        finally:
            my_socket.close()

        return True