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homeassistant-config/deps/lib/python3.10/site-packages/pytapo/media_stream/crypto.py
darthsandmann d1289421b9 updates
2023-02-11 19:37:07 +01:00

74 lines
2.2 KiB
Python

import hashlib
import logging
from typing import AnyStr
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad, unpad
from pytapo.media_stream.error import NonceMissingException
logger = logging.getLogger(__name__)
class AESHelper:
def __init__(
self,
username: bytes,
nonce: bytes,
cloud_password: bytes,
super_secret_key: bytes,
):
if not nonce:
raise NonceMissingException()
self.nonce = nonce
hashed_pwd = hashlib.md5(cloud_password).hexdigest().upper().encode()
if username == b"none":
logger.debug(
"Detected turned off media encryption, using super secret key."
)
if super_secret_key == b"":
raise Exception(
"Media encryption is off and super secret key is not set."
)
key = hashlib.md5(nonce + b":" + super_secret_key).digest()
else:
logger.debug("Detected turned on media encryption, using cloud password.")
key = hashlib.md5(nonce + b":" + hashed_pwd).digest()
iv = hashlib.md5(username + b":" + nonce).digest()
self._cipher = AES.new(key, AES.MODE_CBC, iv)
logger.debug("AES cipher set up correctly")
@classmethod
def from_keyexchange_and_password(
cls, key_exchange: AnyStr, cloud_password: AnyStr, super_secret_key: AnyStr
):
if type(cloud_password) == str:
cloud_password = cloud_password.encode()
if type(key_exchange) == str:
key_exchange = key_exchange.encode()
key_exchange = {
i[0].strip().replace(b'"', b""): i[1].strip().replace(b'"', b"")
for i in (j.split(b"=", 1) for j in key_exchange.split(b" "))
}
if b"nonce" not in key_exchange:
raise NonceMissingException()
return cls(
key_exchange[b"username"],
key_exchange[b"nonce"],
cloud_password,
super_secret_key,
)
def decrypt(self, data: bytes) -> bytes:
return unpad(self._cipher.decrypt(data), 16, style="pkcs7")
def encrypt(self, data: bytes) -> bytes:
return self._cipher.encrypt(pad(data, 16, style="pkcs7"))