211 lines
7.6 KiB
Python
211 lines
7.6 KiB
Python
|
import datetime
|
||
|
|
import logging
|
||
|
|
import os
|
||
|
|
import shutil
|
||
|
|
import tempfile
|
||
|
|
|
||
|
|
from django.conf import settings
|
||
|
|
from django.contrib.sessions.backends.base import (
|
||
|
|
VALID_KEY_CHARS,
|
||
|
|
CreateError,
|
||
|
|
SessionBase,
|
||
|
|
UpdateError,
|
||
|
|
)
|
||
|
|
from django.contrib.sessions.exceptions import InvalidSessionKey
|
||
|
|
from django.core.exceptions import ImproperlyConfigured, SuspiciousOperation
|
||
|
|
|
||
|
|
|
||
|
|
class SessionStore(SessionBase):
|
||
|
|
"""
|
||
|
|
Implement a file based session store.
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(self, session_key=None):
|
||
|
|
self.storage_path = self._get_storage_path()
|
||
|
|
self.file_prefix = settings.SESSION_COOKIE_NAME
|
||
|
|
super().__init__(session_key)
|
||
|
|
|
||
|
|
@classmethod
|
||
|
|
def _get_storage_path(cls):
|
||
|
|
try:
|
||
|
|
return cls._storage_path
|
||
|
|
except AttributeError:
|
||
|
|
storage_path = (
|
||
|
|
getattr(settings, "SESSION_FILE_PATH", None) or tempfile.gettempdir()
|
||
|
|
)
|
||
|
|
# Make sure the storage path is valid.
|
||
|
|
if not os.path.isdir(storage_path):
|
||
|
|
raise ImproperlyConfigured(
|
||
|
|
"The session storage path %r doesn't exist. Please set your"
|
||
|
|
" SESSION_FILE_PATH setting to an existing directory in which"
|
||
|
|
" Django can store session data." % storage_path
|
||
|
|
)
|
||
|
|
|
||
|
|
cls._storage_path = storage_path
|
||
|
|
return storage_path
|
||
|
|
|
||
|
|
def _key_to_file(self, session_key=None):
|
||
|
|
"""
|
||
|
|
Get the file associated with this session key.
|
||
|
|
"""
|
||
|
|
if session_key is None:
|
||
|
|
session_key = self._get_or_create_session_key()
|
||
|
|
|
||
|
|
# Make sure we're not vulnerable to directory traversal. Session keys
|
||
|
|
# should always be md5s, so they should never contain directory
|
||
|
|
# components.
|
||
|
|
if not set(session_key).issubset(VALID_KEY_CHARS):
|
||
|
|
raise InvalidSessionKey("Invalid characters in session key")
|
||
|
|
|
||
|
|
return os.path.join(self.storage_path, self.file_prefix + session_key)
|
||
|
|
|
||
|
|
def _last_modification(self):
|
||
|
|
"""
|
||
|
|
Return the modification time of the file storing the session's content.
|
||
|
|
"""
|
||
|
|
modification = os.stat(self._key_to_file()).st_mtime
|
||
|
|
tz = datetime.timezone.utc if settings.USE_TZ else None
|
||
|
|
return datetime.datetime.fromtimestamp(modification, tz=tz)
|
||
|
|
|
||
|
|
def _expiry_date(self, session_data):
|
||
|
|
"""
|
||
|
|
Return the expiry time of the file storing the session's content.
|
||
|
|
"""
|
||
|
|
return session_data.get("_session_expiry") or (
|
||
|
|
self._last_modification()
|
||
|
|
+ datetime.timedelta(seconds=self.get_session_cookie_age())
|
||
|
|
)
|
||
|
|
|
||
|
|
def load(self):
|
||
|
|
session_data = {}
|
||
|
|
try:
|
||
|
|
with open(self._key_to_file(), encoding="ascii") as session_file:
|
||
|
|
file_data = session_file.read()
|
||
|
|
# Don't fail if there is no data in the session file.
|
||
|
|
# We may have opened the empty placeholder file.
|
||
|
|
if file_data:
|
||
|
|
try:
|
||
|
|
session_data = self.decode(file_data)
|
||
|
|
except (EOFError, SuspiciousOperation) as e:
|
||
|
|
if isinstance(e, SuspiciousOperation):
|
||
|
|
logger = logging.getLogger(
|
||
|
|
"django.security.%s" % e.__class__.__name__
|
||
|
|
)
|
||
|
|
logger.warning(str(e))
|
||
|
|
self.create()
|
||
|
|
|
||
|
|
# Remove expired sessions.
|
||
|
|
expiry_age = self.get_expiry_age(expiry=self._expiry_date(session_data))
|
||
|
|
if expiry_age <= 0:
|
||
|
|
session_data = {}
|
||
|
|
self.delete()
|
||
|
|
self.create()
|
||
|
|
except (OSError, SuspiciousOperation):
|
||
|
|
self._session_key = None
|
||
|
|
return session_data
|
||
|
|
|
||
|
|
def create(self):
|
||
|
|
while True:
|
||
|
|
self._session_key = self._get_new_session_key()
|
||
|
|
try:
|
||
|
|
self.save(must_create=True)
|
||
|
|
except CreateError:
|
||
|
|
continue
|
||
|
|
self.modified = True
|
||
|
|
return
|
||
|
|
|
||
|
|
def save(self, must_create=False):
|
||
|
|
if self.session_key is None:
|
||
|
|
return self.create()
|
||
|
|
# Get the session data now, before we start messing
|
||
|
|
# with the file it is stored within.
|
||
|
|
session_data = self._get_session(no_load=must_create)
|
||
|
|
|
||
|
|
session_file_name = self._key_to_file()
|
||
|
|
|
||
|
|
try:
|
||
|
|
# Make sure the file exists. If it does not already exist, an
|
||
|
|
# empty placeholder file is created.
|
||
|
|
flags = os.O_WRONLY | getattr(os, "O_BINARY", 0)
|
||
|
|
if must_create:
|
||
|
|
flags |= os.O_EXCL | os.O_CREAT
|
||
|
|
fd = os.open(session_file_name, flags)
|
||
|
|
os.close(fd)
|
||
|
|
except FileNotFoundError:
|
||
|
|
if not must_create:
|
||
|
|
raise UpdateError
|
||
|
|
except FileExistsError:
|
||
|
|
if must_create:
|
||
|
|
raise CreateError
|
||
|
|
|
||
|
|
# Write the session file without interfering with other threads
|
||
|
|
# or processes. By writing to an atomically generated temporary
|
||
|
|
# file and then using the atomic os.rename() to make the complete
|
||
|
|
# file visible, we avoid having to lock the session file, while
|
||
|
|
# still maintaining its integrity.
|
||
|
|
#
|
||
|
|
# Note: Locking the session file was explored, but rejected in part
|
||
|
|
# because in order to be atomic and cross-platform, it required a
|
||
|
|
# long-lived lock file for each session, doubling the number of
|
||
|
|
# files in the session storage directory at any given time. This
|
||
|
|
# rename solution is cleaner and avoids any additional overhead
|
||
|
|
# when reading the session data, which is the more common case
|
||
|
|
# unless SESSION_SAVE_EVERY_REQUEST = True.
|
||
|
|
#
|
||
|
|
# See ticket #8616.
|
||
|
|
dir, prefix = os.path.split(session_file_name)
|
||
|
|
|
||
|
|
try:
|
||
|
|
output_file_fd, output_file_name = tempfile.mkstemp(
|
||
|
|
dir=dir, prefix=prefix + "_out_"
|
||
|
|
)
|
||
|
|
renamed = False
|
||
|
|
try:
|
||
|
|
try:
|
||
|
|
os.write(output_file_fd, self.encode(session_data).encode())
|
||
|
|
finally:
|
||
|
|
os.close(output_file_fd)
|
||
|
|
|
||
|
|
# This will atomically rename the file (os.rename) if the OS
|
||
|
|
# supports it. Otherwise this will result in a shutil.copy2
|
||
|
|
# and os.unlink (for example on Windows). See #9084.
|
||
|
|
shutil.move(output_file_name, session_file_name)
|
||
|
|
renamed = True
|
||
|
|
finally:
|
||
|
|
if not renamed:
|
||
|
|
os.unlink(output_file_name)
|
||
|
|
except (EOFError, OSError):
|
||
|
|
pass
|
||
|
|
|
||
|
|
def exists(self, session_key):
|
||
|
|
return os.path.exists(self._key_to_file(session_key))
|
||
|
|
|
||
|
|
def delete(self, session_key=None):
|
||
|
|
if session_key is None:
|
||
|
|
if self.session_key is None:
|
||
|
|
return
|
||
|
|
session_key = self.session_key
|
||
|
|
try:
|
||
|
|
os.unlink(self._key_to_file(session_key))
|
||
|
|
except OSError:
|
||
|
|
pass
|
||
|
|
|
||
|
|
def clean(self):
|
||
|
|
pass
|
||
|
|
|
||
|
|
@classmethod
|
||
|
|
def clear_expired(cls):
|
||
|
|
storage_path = cls._get_storage_path()
|
||
|
|
file_prefix = settings.SESSION_COOKIE_NAME
|
||
|
|
|
||
|
|
for session_file in os.listdir(storage_path):
|
||
|
|
if not session_file.startswith(file_prefix):
|
||
|
|
continue
|
||
|
|
session_key = session_file[len(file_prefix) :]
|
||
|
|
session = cls(session_key)
|
||
|
|
# When an expired session is loaded, its file is removed, and a
|
||
|
|
# new file is immediately created. Prevent this by disabling
|
||
|
|
# the create() method.
|
||
|
|
session.create = lambda: None
|
||
|
|
session.load()
|