281 lines
8.8 KiB
Python
281 lines
8.8 KiB
Python
import base64
|
|
import time
|
|
from datetime import datetime, timedelta
|
|
try:
|
|
import cPickle as pickle
|
|
except ImportError:
|
|
import pickle
|
|
|
|
from django.conf import settings
|
|
from django.core.exceptions import SuspiciousOperation
|
|
from django.utils.crypto import constant_time_compare
|
|
from django.utils.crypto import get_random_string
|
|
from django.utils.crypto import salted_hmac
|
|
from django.utils import timezone
|
|
|
|
class CreateError(Exception):
|
|
"""
|
|
Used internally as a consistent exception type to catch from save (see the
|
|
docstring for SessionBase.save() for details).
|
|
"""
|
|
pass
|
|
|
|
class SessionBase(object):
|
|
"""
|
|
Base class for all Session classes.
|
|
"""
|
|
TEST_COOKIE_NAME = 'testcookie'
|
|
TEST_COOKIE_VALUE = 'worked'
|
|
|
|
def __init__(self, session_key=None):
|
|
self._session_key = session_key
|
|
self.accessed = False
|
|
self.modified = False
|
|
|
|
def __contains__(self, key):
|
|
return key in self._session
|
|
|
|
def __getitem__(self, key):
|
|
return self._session[key]
|
|
|
|
def __setitem__(self, key, value):
|
|
self._session[key] = value
|
|
self.modified = True
|
|
|
|
def __delitem__(self, key):
|
|
del self._session[key]
|
|
self.modified = True
|
|
|
|
def get(self, key, default=None):
|
|
return self._session.get(key, default)
|
|
|
|
def pop(self, key, *args):
|
|
self.modified = self.modified or key in self._session
|
|
return self._session.pop(key, *args)
|
|
|
|
def setdefault(self, key, value):
|
|
if key in self._session:
|
|
return self._session[key]
|
|
else:
|
|
self.modified = True
|
|
self._session[key] = value
|
|
return value
|
|
|
|
def set_test_cookie(self):
|
|
self[self.TEST_COOKIE_NAME] = self.TEST_COOKIE_VALUE
|
|
|
|
def test_cookie_worked(self):
|
|
return self.get(self.TEST_COOKIE_NAME) == self.TEST_COOKIE_VALUE
|
|
|
|
def delete_test_cookie(self):
|
|
del self[self.TEST_COOKIE_NAME]
|
|
|
|
def _hash(self, value):
|
|
key_salt = "django.contrib.sessions" + self.__class__.__name__
|
|
return salted_hmac(key_salt, value).hexdigest()
|
|
|
|
def encode(self, session_dict):
|
|
"Returns the given session dictionary pickled and encoded as a string."
|
|
pickled = pickle.dumps(session_dict, pickle.HIGHEST_PROTOCOL)
|
|
hash = self._hash(pickled)
|
|
return base64.encodestring(hash + ":" + pickled)
|
|
|
|
def decode(self, session_data):
|
|
encoded_data = base64.decodestring(session_data)
|
|
try:
|
|
# could produce ValueError if there is no ':'
|
|
hash, pickled = encoded_data.split(':', 1)
|
|
expected_hash = self._hash(pickled)
|
|
if not constant_time_compare(hash, expected_hash):
|
|
raise SuspiciousOperation("Session data corrupted")
|
|
else:
|
|
return pickle.loads(pickled)
|
|
except Exception:
|
|
# ValueError, SuspiciousOperation, unpickling exceptions. If any of
|
|
# these happen, just return an empty dictionary (an empty session).
|
|
return {}
|
|
|
|
def update(self, dict_):
|
|
self._session.update(dict_)
|
|
self.modified = True
|
|
|
|
def has_key(self, key):
|
|
return key in self._session
|
|
|
|
def keys(self):
|
|
return self._session.keys()
|
|
|
|
def values(self):
|
|
return self._session.values()
|
|
|
|
def items(self):
|
|
return self._session.items()
|
|
|
|
def iterkeys(self):
|
|
return self._session.iterkeys()
|
|
|
|
def itervalues(self):
|
|
return self._session.itervalues()
|
|
|
|
def iteritems(self):
|
|
return self._session.iteritems()
|
|
|
|
def clear(self):
|
|
# To avoid unnecessary persistent storage accesses, we set up the
|
|
# internals directly (loading data wastes time, since we are going to
|
|
# set it to an empty dict anyway).
|
|
self._session_cache = {}
|
|
self.accessed = True
|
|
self.modified = True
|
|
|
|
def _get_new_session_key(self):
|
|
"Returns session key that isn't being used."
|
|
# Todo: move to 0-9a-z charset in 1.5
|
|
hex_chars = '1234567890abcdef'
|
|
# session_key should not be case sensitive because some backends
|
|
# can store it on case insensitive file systems.
|
|
while True:
|
|
session_key = get_random_string(32, hex_chars)
|
|
if not self.exists(session_key):
|
|
break
|
|
return session_key
|
|
|
|
def _get_or_create_session_key(self):
|
|
if self._session_key is None:
|
|
self._session_key = self._get_new_session_key()
|
|
return self._session_key
|
|
|
|
def _get_session_key(self):
|
|
return self._session_key
|
|
|
|
session_key = property(_get_session_key)
|
|
|
|
def _get_session(self, no_load=False):
|
|
"""
|
|
Lazily loads session from storage (unless "no_load" is True, when only
|
|
an empty dict is stored) and stores it in the current instance.
|
|
"""
|
|
self.accessed = True
|
|
try:
|
|
return self._session_cache
|
|
except AttributeError:
|
|
if self.session_key is None or no_load:
|
|
self._session_cache = {}
|
|
else:
|
|
self._session_cache = self.load()
|
|
return self._session_cache
|
|
|
|
_session = property(_get_session)
|
|
|
|
def get_expiry_age(self):
|
|
"""Get the number of seconds until the session expires."""
|
|
expiry = self.get('_session_expiry')
|
|
if not expiry: # Checks both None and 0 cases
|
|
return settings.SESSION_COOKIE_AGE
|
|
if not isinstance(expiry, datetime):
|
|
return expiry
|
|
delta = expiry - timezone.now()
|
|
return delta.days * 86400 + delta.seconds
|
|
|
|
def get_expiry_date(self):
|
|
"""Get session the expiry date (as a datetime object)."""
|
|
expiry = self.get('_session_expiry')
|
|
if isinstance(expiry, datetime):
|
|
return expiry
|
|
if not expiry: # Checks both None and 0 cases
|
|
expiry = settings.SESSION_COOKIE_AGE
|
|
return timezone.now() + timedelta(seconds=expiry)
|
|
|
|
def set_expiry(self, value):
|
|
"""
|
|
Sets a custom expiration for the session. ``value`` can be an integer,
|
|
a Python ``datetime`` or ``timedelta`` object or ``None``.
|
|
|
|
If ``value`` is an integer, the session will expire after that many
|
|
seconds of inactivity. If set to ``0`` then the session will expire on
|
|
browser close.
|
|
|
|
If ``value`` is a ``datetime`` or ``timedelta`` object, the session
|
|
will expire at that specific future time.
|
|
|
|
If ``value`` is ``None``, the session uses the global session expiry
|
|
policy.
|
|
"""
|
|
if value is None:
|
|
# Remove any custom expiration for this session.
|
|
try:
|
|
del self['_session_expiry']
|
|
except KeyError:
|
|
pass
|
|
return
|
|
if isinstance(value, timedelta):
|
|
value = timezone.now() + value
|
|
self['_session_expiry'] = value
|
|
|
|
def get_expire_at_browser_close(self):
|
|
"""
|
|
Returns ``True`` if the session is set to expire when the browser
|
|
closes, and ``False`` if there's an expiry date. Use
|
|
``get_expiry_date()`` or ``get_expiry_age()`` to find the actual expiry
|
|
date/age, if there is one.
|
|
"""
|
|
if self.get('_session_expiry') is None:
|
|
return settings.SESSION_EXPIRE_AT_BROWSER_CLOSE
|
|
return self.get('_session_expiry') == 0
|
|
|
|
def flush(self):
|
|
"""
|
|
Removes the current session data from the database and regenerates the
|
|
key.
|
|
"""
|
|
self.clear()
|
|
self.delete()
|
|
self.create()
|
|
|
|
def cycle_key(self):
|
|
"""
|
|
Creates a new session key, whilst retaining the current session data.
|
|
"""
|
|
data = self._session_cache
|
|
key = self.session_key
|
|
self.create()
|
|
self._session_cache = data
|
|
self.delete(key)
|
|
|
|
# Methods that child classes must implement.
|
|
|
|
def exists(self, session_key):
|
|
"""
|
|
Returns True if the given session_key already exists.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def create(self):
|
|
"""
|
|
Creates a new session instance. Guaranteed to create a new object with
|
|
a unique key and will have saved the result once (with empty data)
|
|
before the method returns.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def save(self, must_create=False):
|
|
"""
|
|
Saves the session data. If 'must_create' is True, a new session object
|
|
is created (otherwise a CreateError exception is raised). Otherwise,
|
|
save() can update an existing object with the same key.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def delete(self, session_key=None):
|
|
"""
|
|
Deletes the session data under this key. If the key is None, the
|
|
current session key value is used.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def load(self):
|
|
"""
|
|
Loads the session data and returns a dictionary.
|
|
"""
|
|
raise NotImplementedError
|