import json
import base64
from cryptography import fernet
from cryptography.fernet import InvalidToken
from . import AbstractStorage, Session
from .log import log
class EncryptedCookieStorage(AbstractStorage):
"""Encrypted JSON storage.
"""
def __init__(self, secret_key, *, cookie_name="AIOHTTP_SESSION",
domain=None, max_age=None, path='/',
secure=None, httponly=True,
encoder=json.dumps, decoder=json.loads):
super().__init__(cookie_name=cookie_name, domain=domain,
max_age=max_age, path=path, secure=secure,
httponly=httponly,
encoder=encoder, decoder=decoder)
if isinstance(secret_key, str):
pass
elif isinstance(secret_key, (bytes, bytearray)):
secret_key = base64.urlsafe_b64encode(secret_key)
self._fernet = fernet.Fernet(secret_key)
async def load_session(self, request):
cookie = self.load_cookie(request)
if cookie is None:
return Session(None, data=None, new=True, max_age=self.max_age)
else:
try:
data = self._decoder(
self._fernet.decrypt(
cookie.encode('utf-8'),
ttl=self.max_age
).decode('utf-8')
)
return Session(None, data=data,
new=False, max_age=self.max_age)
except InvalidToken:
log.warning("Cannot decrypt cookie value, "
"create a new fresh session")
return Session(None, data=None, new=True, max_age=self.max_age)
async def save_session(self, request, response, session):
if session.empty:
return self.save_cookie(response, '',
max_age=session.max_age)
cookie_data = self._encoder(
self._get_session_data(session)
).encode('utf-8')
self.save_cookie(
response,
self._fernet.encrypt(cookie_data).decode('utf-8'),
max_age=session.max_age
)
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