mirror of
https://github.com/janeczku/calibre-web
synced 2024-12-27 02:20:31 +00:00
349 lines
12 KiB
Python
349 lines
12 KiB
Python
# -*- coding: utf-8 -*-
|
|
r"""
|
|
werkzeug.contrib.sessions
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
This module contains some helper classes that help one to add session
|
|
support to a python WSGI application. For full client-side session
|
|
storage see :mod:`~werkzeug.contrib.securecookie` which implements a
|
|
secure, client-side session storage.
|
|
|
|
|
|
Application Integration
|
|
=======================
|
|
|
|
::
|
|
|
|
from werkzeug.contrib.sessions import SessionMiddleware, \
|
|
FilesystemSessionStore
|
|
|
|
app = SessionMiddleware(app, FilesystemSessionStore())
|
|
|
|
The current session will then appear in the WSGI environment as
|
|
`werkzeug.session`. However it's recommended to not use the middleware
|
|
but the stores directly in the application. However for very simple
|
|
scripts a middleware for sessions could be sufficient.
|
|
|
|
This module does not implement methods or ways to check if a session is
|
|
expired. That should be done by a cronjob and storage specific. For
|
|
example to prune unused filesystem sessions one could check the modified
|
|
time of the files. It sessions are stored in the database the new()
|
|
method should add an expiration timestamp for the session.
|
|
|
|
For better flexibility it's recommended to not use the middleware but the
|
|
store and session object directly in the application dispatching::
|
|
|
|
session_store = FilesystemSessionStore()
|
|
|
|
def application(environ, start_response):
|
|
request = Request(environ)
|
|
sid = request.cookies.get('cookie_name')
|
|
if sid is None:
|
|
request.session = session_store.new()
|
|
else:
|
|
request.session = session_store.get(sid)
|
|
response = get_the_response_object(request)
|
|
if request.session.should_save:
|
|
session_store.save(request.session)
|
|
response.set_cookie('cookie_name', request.session.sid)
|
|
return response(environ, start_response)
|
|
|
|
:copyright: (c) 2013 by the Werkzeug Team, see AUTHORS for more details.
|
|
:license: BSD, see LICENSE for more details.
|
|
"""
|
|
import re
|
|
import os
|
|
import sys
|
|
import tempfile
|
|
from os import path
|
|
from time import time
|
|
from random import random
|
|
from hashlib import sha1
|
|
from pickle import dump, load, HIGHEST_PROTOCOL
|
|
|
|
from werkzeug.datastructures import CallbackDict
|
|
from werkzeug.utils import dump_cookie, parse_cookie
|
|
from werkzeug.wsgi import ClosingIterator
|
|
from werkzeug.posixemulation import rename
|
|
from werkzeug._compat import PY2, text_type
|
|
|
|
|
|
_sha1_re = re.compile(r'^[a-f0-9]{40}$')
|
|
|
|
|
|
def _urandom():
|
|
if hasattr(os, 'urandom'):
|
|
return os.urandom(30)
|
|
return random()
|
|
|
|
|
|
def generate_key(salt=None):
|
|
if salt is None:
|
|
salt = repr(salt).encode('ascii')
|
|
return sha1(b''.join([
|
|
salt,
|
|
str(time()).encode('ascii'),
|
|
_urandom()
|
|
])).hexdigest()
|
|
|
|
|
|
class ModificationTrackingDict(CallbackDict):
|
|
__slots__ = ('modified',)
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
def on_update(self):
|
|
self.modified = True
|
|
self.modified = False
|
|
CallbackDict.__init__(self, on_update=on_update)
|
|
dict.update(self, *args, **kwargs)
|
|
|
|
def copy(self):
|
|
"""Create a flat copy of the dict."""
|
|
missing = object()
|
|
result = object.__new__(self.__class__)
|
|
for name in self.__slots__:
|
|
val = getattr(self, name, missing)
|
|
if val is not missing:
|
|
setattr(result, name, val)
|
|
return result
|
|
|
|
def __copy__(self):
|
|
return self.copy()
|
|
|
|
|
|
class Session(ModificationTrackingDict):
|
|
"""Subclass of a dict that keeps track of direct object changes. Changes
|
|
in mutable structures are not tracked, for those you have to set
|
|
`modified` to `True` by hand.
|
|
"""
|
|
__slots__ = ModificationTrackingDict.__slots__ + ('sid', 'new')
|
|
|
|
def __init__(self, data, sid, new=False):
|
|
ModificationTrackingDict.__init__(self, data)
|
|
self.sid = sid
|
|
self.new = new
|
|
|
|
def __repr__(self):
|
|
return '<%s %s%s>' % (
|
|
self.__class__.__name__,
|
|
dict.__repr__(self),
|
|
self.should_save and '*' or ''
|
|
)
|
|
|
|
@property
|
|
def should_save(self):
|
|
"""True if the session should be saved.
|
|
|
|
.. versionchanged:: 0.6
|
|
By default the session is now only saved if the session is
|
|
modified, not if it is new like it was before.
|
|
"""
|
|
return self.modified
|
|
|
|
|
|
class SessionStore(object):
|
|
"""Baseclass for all session stores. The Werkzeug contrib module does not
|
|
implement any useful stores besides the filesystem store, application
|
|
developers are encouraged to create their own stores.
|
|
|
|
:param session_class: The session class to use. Defaults to
|
|
:class:`Session`.
|
|
"""
|
|
|
|
def __init__(self, session_class=None):
|
|
if session_class is None:
|
|
session_class = Session
|
|
self.session_class = session_class
|
|
|
|
def is_valid_key(self, key):
|
|
"""Check if a key has the correct format."""
|
|
return _sha1_re.match(key) is not None
|
|
|
|
def generate_key(self, salt=None):
|
|
"""Simple function that generates a new session key."""
|
|
return generate_key(salt)
|
|
|
|
def new(self):
|
|
"""Generate a new session."""
|
|
return self.session_class({}, self.generate_key(), True)
|
|
|
|
def save(self, session):
|
|
"""Save a session."""
|
|
|
|
def save_if_modified(self, session):
|
|
"""Save if a session class wants an update."""
|
|
if session.should_save:
|
|
self.save(session)
|
|
|
|
def delete(self, session):
|
|
"""Delete a session."""
|
|
|
|
def get(self, sid):
|
|
"""Get a session for this sid or a new session object. This method
|
|
has to check if the session key is valid and create a new session if
|
|
that wasn't the case.
|
|
"""
|
|
return self.session_class({}, sid, True)
|
|
|
|
|
|
#: used for temporary files by the filesystem session store
|
|
_fs_transaction_suffix = '.__wz_sess'
|
|
|
|
|
|
class FilesystemSessionStore(SessionStore):
|
|
"""Simple example session store that saves sessions on the filesystem.
|
|
This store works best on POSIX systems and Windows Vista / Windows
|
|
Server 2008 and newer.
|
|
|
|
.. versionchanged:: 0.6
|
|
`renew_missing` was added. Previously this was considered `True`,
|
|
now the default changed to `False` and it can be explicitly
|
|
deactivated.
|
|
|
|
:param path: the path to the folder used for storing the sessions.
|
|
If not provided the default temporary directory is used.
|
|
:param filename_template: a string template used to give the session
|
|
a filename. ``%s`` is replaced with the
|
|
session id.
|
|
:param session_class: The session class to use. Defaults to
|
|
:class:`Session`.
|
|
:param renew_missing: set to `True` if you want the store to
|
|
give the user a new sid if the session was
|
|
not yet saved.
|
|
"""
|
|
|
|
def __init__(self, path=None, filename_template='werkzeug_%s.sess',
|
|
session_class=None, renew_missing=False, mode=0o644):
|
|
SessionStore.__init__(self, session_class)
|
|
if path is None:
|
|
path = tempfile.gettempdir()
|
|
self.path = path
|
|
if isinstance(filename_template, text_type) and PY2:
|
|
filename_template = filename_template.encode(
|
|
sys.getfilesystemencoding() or 'utf-8')
|
|
assert not filename_template.endswith(_fs_transaction_suffix), \
|
|
'filename templates may not end with %s' % _fs_transaction_suffix
|
|
self.filename_template = filename_template
|
|
self.renew_missing = renew_missing
|
|
self.mode = mode
|
|
|
|
def get_session_filename(self, sid):
|
|
# out of the box, this should be a strict ASCII subset but
|
|
# you might reconfigure the session object to have a more
|
|
# arbitrary string.
|
|
if isinstance(sid, text_type) and PY2:
|
|
sid = sid.encode(sys.getfilesystemencoding() or 'utf-8')
|
|
return path.join(self.path, self.filename_template % sid)
|
|
|
|
def save(self, session):
|
|
fn = self.get_session_filename(session.sid)
|
|
fd, tmp = tempfile.mkstemp(suffix=_fs_transaction_suffix,
|
|
dir=self.path)
|
|
f = os.fdopen(fd, 'wb')
|
|
try:
|
|
dump(dict(session), f, HIGHEST_PROTOCOL)
|
|
finally:
|
|
f.close()
|
|
try:
|
|
rename(tmp, fn)
|
|
os.chmod(fn, self.mode)
|
|
except (IOError, OSError):
|
|
pass
|
|
|
|
def delete(self, session):
|
|
fn = self.get_session_filename(session.sid)
|
|
try:
|
|
os.unlink(fn)
|
|
except OSError:
|
|
pass
|
|
|
|
def get(self, sid):
|
|
if not self.is_valid_key(sid):
|
|
return self.new()
|
|
try:
|
|
f = open(self.get_session_filename(sid), 'rb')
|
|
except IOError:
|
|
if self.renew_missing:
|
|
return self.new()
|
|
data = {}
|
|
else:
|
|
try:
|
|
try:
|
|
data = load(f)
|
|
except Exception:
|
|
data = {}
|
|
finally:
|
|
f.close()
|
|
return self.session_class(data, sid, False)
|
|
|
|
def list(self):
|
|
"""Lists all sessions in the store.
|
|
|
|
.. versionadded:: 0.6
|
|
"""
|
|
before, after = self.filename_template.split('%s', 1)
|
|
filename_re = re.compile(r'%s(.{5,})%s$' % (re.escape(before),
|
|
re.escape(after)))
|
|
result = []
|
|
for filename in os.listdir(self.path):
|
|
#: this is a session that is still being saved.
|
|
if filename.endswith(_fs_transaction_suffix):
|
|
continue
|
|
match = filename_re.match(filename)
|
|
if match is not None:
|
|
result.append(match.group(1))
|
|
return result
|
|
|
|
|
|
class SessionMiddleware(object):
|
|
"""A simple middleware that puts the session object of a store provided
|
|
into the WSGI environ. It automatically sets cookies and restores
|
|
sessions.
|
|
|
|
However a middleware is not the preferred solution because it won't be as
|
|
fast as sessions managed by the application itself and will put a key into
|
|
the WSGI environment only relevant for the application which is against
|
|
the concept of WSGI.
|
|
|
|
The cookie parameters are the same as for the :func:`~dump_cookie`
|
|
function just prefixed with ``cookie_``. Additionally `max_age` is
|
|
called `cookie_age` and not `cookie_max_age` because of backwards
|
|
compatibility.
|
|
"""
|
|
|
|
def __init__(self, app, store, cookie_name='session_id',
|
|
cookie_age=None, cookie_expires=None, cookie_path='/',
|
|
cookie_domain=None, cookie_secure=None,
|
|
cookie_httponly=False, environ_key='werkzeug.session'):
|
|
self.app = app
|
|
self.store = store
|
|
self.cookie_name = cookie_name
|
|
self.cookie_age = cookie_age
|
|
self.cookie_expires = cookie_expires
|
|
self.cookie_path = cookie_path
|
|
self.cookie_domain = cookie_domain
|
|
self.cookie_secure = cookie_secure
|
|
self.cookie_httponly = cookie_httponly
|
|
self.environ_key = environ_key
|
|
|
|
def __call__(self, environ, start_response):
|
|
cookie = parse_cookie(environ.get('HTTP_COOKIE', ''))
|
|
sid = cookie.get(self.cookie_name, None)
|
|
if sid is None:
|
|
session = self.store.new()
|
|
else:
|
|
session = self.store.get(sid)
|
|
environ[self.environ_key] = session
|
|
|
|
def injecting_start_response(status, headers, exc_info=None):
|
|
if session.should_save:
|
|
self.store.save(session)
|
|
headers.append(('Set-Cookie', dump_cookie(self.cookie_name,
|
|
session.sid, self.cookie_age,
|
|
self.cookie_expires, self.cookie_path,
|
|
self.cookie_domain, self.cookie_secure,
|
|
self.cookie_httponly)))
|
|
return start_response(status, headers, exc_info)
|
|
return ClosingIterator(self.app(environ, injecting_start_response),
|
|
lambda: self.store.save_if_modified(session))
|