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