app-MAIL-temp/app/session.py

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import uuid
from typing import Optional
import flask
from flask import current_app, session
from flask_login import logout_user
try:
import cPickle as pickle
except ImportError:
import pickle
import itsdangerous
from flask.sessions import SessionMixin, SessionInterface
from werkzeug.datastructures import CallbackDict
SESSION_PREFIX = "session"
class ServerSession(CallbackDict, SessionMixin):
def __init__(self, initial=None, session_id=None):
def on_update(self):
self.modified = True
super(ServerSession, self).__init__(initial, on_update)
self.session_id = session_id
self.modified = False
class RedisSessionStore(SessionInterface):
def __init__(self, redis_w, redis_r, app):
self._redis_w = redis_w
self._redis_r = redis_r
self._app = app
@classmethod
def _get_signer(cls, app) -> itsdangerous.Signer:
return itsdangerous.Signer(
app.secret_key, salt="session", key_derivation="hmac"
)
@classmethod
def _get_key(cls, session_Id: str) -> str:
return f"{SESSION_PREFIX}:{session_Id}"
@classmethod
def extract_and_validate_session_id(
cls, app: flask.Flask, request: flask.Request
) -> Optional[str]:
unverified_session_Id = request.cookies.get(app.session_cookie_name)
if not unverified_session_Id:
return None
signer = cls._get_signer(app)
try:
sid_as_bytes = signer.unsign(unverified_session_Id)
return sid_as_bytes.decode()
except itsdangerous.BadSignature:
return None
def purge_session(self, session: ServerSession):
try:
self._redis_w.delete(self._get_key(session.session_id))
session.session_id = str(uuid.uuid4())
except AttributeError:
pass
def open_session(self, app: flask.Flask, request: flask.Request):
session_id = self.extract_and_validate_session_id(app, request)
if not session_id:
return ServerSession(session_id=str(uuid.uuid4()))
val = self._redis_r.get(self._get_key(session_id))
if val is not None:
try:
data = pickle.loads(val)
return ServerSession(data, session_id=session_id)
except:
pass
return ServerSession(session_id=str(uuid.uuid4()))
def save_session(
self, app: flask.Flask, session: ServerSession, response: flask.Response
):
domain = self.get_cookie_domain(app)
path = self.get_cookie_path(app)
httponly = self.get_cookie_httponly(app)
secure = self.get_cookie_secure(app)
expires = self.get_expiration_time(app, session)
val = pickle.dumps(dict(session))
ttl = int(app.permanent_session_lifetime.total_seconds())
# Only 5 minutes for non-authenticated sessions.
# We need to keep the non-authenticated ones because the csrf token is stored in the session.
if "_user_id" not in session:
ttl = 300
self._redis_w.setex(
name=self._get_key(session.session_id),
value=val,
time=ttl,
)
signed_session_id = self._get_signer(app).sign(
itsdangerous.want_bytes(session.session_id)
)
response.set_cookie(
app.session_cookie_name,
signed_session_id,
expires=expires,
httponly=httponly,
domain=domain,
path=path,
secure=secure,
)
def logout_session():
logout_user()
purge_fn = getattr(current_app.session_interface, "purge_session", None)
if callable(purge_fn):
purge_fn(session)