django1/django/contrib/sessions/backends/signed_cookies.py

82 lines
2.6 KiB
Python

from django.contrib.sessions.backends.base import SessionBase
from django.core import signing
class SessionStore(SessionBase):
def load(self):
"""
Load the data from the key itself instead of fetching from some
external data store. Opposite of _get_session_key(), raise BadSignature
if signature fails.
"""
try:
return signing.loads(
self.session_key,
serializer=self.serializer,
# This doesn't handle non-default expiry dates, see #19201
max_age=self.get_session_cookie_age(),
salt='django.contrib.sessions.backends.signed_cookies',
)
except Exception:
# BadSignature, ValueError, or unpickling exceptions. If any of
# these happen, reset the session.
self.create()
return {}
def create(self):
"""
To create a new key, set the modified flag so that the cookie is set
on the client for the current request.
"""
self.modified = True
def save(self, must_create=False):
"""
To save, get the session key as a securely signed string and then set
the modified flag so that the cookie is set on the client for the
current request.
"""
self._session_key = self._get_session_key()
self.modified = True
def exists(self, session_key=None):
"""
This method makes sense when you're talking to a shared resource, but
it doesn't matter when you're storing the information in the client's
cookie.
"""
return False
def delete(self, session_key=None):
"""
To delete, clear the session key and the underlying data structure
and set the modified flag so that the cookie is set on the client for
the current request.
"""
self._session_key = ''
self._session_cache = {}
self.modified = True
def cycle_key(self):
"""
Keep the same data but with a new key. Call save() and it will
automatically save a cookie with a new key at the end of the request.
"""
self.save()
def _get_session_key(self):
"""
Instead of generating a random string, generate a secure url-safe
base64-encoded string of data as our session key.
"""
return signing.dumps(
self._session, compress=True,
salt='django.contrib.sessions.backends.signed_cookies',
serializer=self.serializer,
)
@classmethod
def clear_expired(cls):
pass