Files
iRedAdmin-Pro-SQL/web/session.py
2023-04-10 07:22:09 +02:00

458 lines
13 KiB
Python

"""
Session Management
(from web.py)
"""
import datetime
import os
import os.path
import shutil
import threading
import time
from copy import deepcopy
from hashlib import sha1
from . import utils
from . import webapi as web
from .py3helpers import iteritems
try:
import cPickle as pickle
except ImportError:
import pickle
from base64 import decodebytes, encodebytes
__all__ = ["Session", "SessionExpired", "Store", "DiskStore", "DBStore", "MemoryStore"]
web.config.session_parameters = utils.storage(
{
"cookie_name": "webpy_session_id",
"cookie_domain": None,
"cookie_path": None,
"samesite": None,
"timeout": 86400, # 24 * 60 * 60, # 24 hours in seconds
"ignore_expiry": True,
"ignore_change_ip": True,
"secret_key": "fLjUfxqXtfNoIldA0A0J",
"expired_message": "Session expired",
"httponly": True,
"secure": False,
}
)
class SessionExpired(web.HTTPError):
def __init__(self, message):
web.HTTPError.__init__(self, "200 OK", {}, data=message)
class Session:
"""Session management for web.py"""
__slots__ = [
"store",
"_initializer",
"_last_cleanup_time",
"_config",
"_data",
"__getitem__",
"__setitem__",
"__delitem__",
]
def __init__(self, app, store, initializer=None):
self.store = store
self._initializer = initializer
self._last_cleanup_time = 0
self._config = utils.storage(web.config.session_parameters)
self._data = utils.threadeddict()
self.__getitem__ = self._data.__getitem__
self.__setitem__ = self._data.__setitem__
self.__delitem__ = self._data.__delitem__
if app:
app.add_processor(self._processor)
def __contains__(self, name):
return name in self._data
def __getattr__(self, name):
return getattr(self._data, name)
def __setattr__(self, name, value):
if name in self.__slots__:
object.__setattr__(self, name, value)
else:
setattr(self._data, name, value)
def __delattr__(self, name):
delattr(self._data, name)
def _processor(self, handler):
"""Application processor to setup session for every request"""
self._cleanup()
self._load()
try:
return handler()
finally:
self._save()
def _load(self):
"""Load the session from the store, by the id from cookie"""
cookie_name = self._config.cookie_name
self.session_id = web.cookies().get(cookie_name)
# protection against session_id tampering
if self.session_id and not self._valid_session_id(self.session_id):
self.session_id = None
self._check_expiry()
if self.session_id:
d = self.store[self.session_id]
self.update(d)
self._validate_ip()
if not self.session_id:
self.session_id = self._generate_session_id()
if self._initializer:
if isinstance(self._initializer, dict):
self.update(deepcopy(self._initializer))
elif hasattr(self._initializer, "__call__"):
self._initializer()
self.ip = web.ctx.ip
def _check_expiry(self):
# check for expiry
if self.session_id and self.session_id not in self.store:
if self._config.ignore_expiry:
self.session_id = None
else:
return self.expired()
def _validate_ip(self):
# check for change of IP
if self.session_id and self.get("ip", None) != web.ctx.ip:
if not self._config.ignore_change_ip:
return self.expired()
def _save(self):
current_values = dict(self._data)
del current_values["session_id"]
del current_values["ip"]
if not self.get("_killed"):
self._setcookie(self.session_id)
self.store[self.session_id] = dict(self._data)
else:
if web.cookies().get(self._config.cookie_name):
self._setcookie(self.session_id, expires=-1)
def _setcookie(self, session_id, expires="", **kw):
cookie_name = self._config.cookie_name
cookie_domain = self._config.cookie_domain
cookie_path = self._config.cookie_path
httponly = self._config.httponly
secure = self._config.secure
samesite = kw.get("samesite", self._config.get("samesite", None))
web.setcookie(
cookie_name,
session_id,
expires=expires,
domain=cookie_domain,
httponly=httponly,
secure=secure,
path=cookie_path,
samesite=samesite,
)
def _generate_session_id(self):
"""Generate a random id for session"""
while True:
rand = os.urandom(16)
now = time.time()
secret_key = self._config.secret_key
hashable = f"{rand}{now}{utils.safestr(web.ctx.ip)}{secret_key}"
session_id = sha1(hashable.encode("utf-8")).hexdigest()
if session_id not in self.store:
break
return session_id
def _valid_session_id(self, session_id):
rx = utils.re_compile("^[0-9a-fA-F]+$")
return rx.match(session_id)
def _cleanup(self):
"""Cleanup the stored sessions"""
current_time = time.time()
timeout = self._config.timeout
if current_time - self._last_cleanup_time > timeout:
self.store.cleanup(timeout)
self._last_cleanup_time = current_time
def expired(self):
"""Called when an expired session is atime"""
self._killed = True
self._save()
raise SessionExpired(self._config.expired_message)
def kill(self):
"""Kill the session, make it no longer available"""
del self.store[self.session_id]
self._killed = True
class Store:
"""Base class for session stores"""
def __contains__(self, key):
raise NotImplementedError()
def __getitem__(self, key):
raise NotImplementedError()
def __setitem__(self, key, value):
raise NotImplementedError()
def cleanup(self, timeout):
"""removes all the expired sessions"""
raise NotImplementedError()
def encode(self, session_dict):
"""encodes session dict as a string"""
pickled = pickle.dumps(session_dict)
return encodebytes(pickled)
def decode(self, session_data):
"""decodes the data to get back the session dict"""
if isinstance(session_data, str):
session_data = session_data.encode()
pickled = decodebytes(session_data)
return pickle.loads(pickled)
class DiskStore(Store):
"""
Store for saving a session on disk.
>>> import tempfile
>>> root = tempfile.mkdtemp()
>>> s = DiskStore(root)
>>> s['a'] = 'foo'
>>> s['a']
'foo'
>>> time.sleep(0.01)
>>> s.cleanup(0.01)
>>> s['a']
Traceback (most recent call last):
...
KeyError: 'a'
"""
def __init__(self, root):
# if the storage root doesn't exists, create it.
if not os.path.exists(root):
os.makedirs(os.path.abspath(root))
self.root = root
def _get_path(self, key):
if os.path.sep in key:
raise ValueError("Bad key: %s" % repr(key))
return os.path.join(self.root, key)
def __contains__(self, key):
path = self._get_path(key)
return os.path.exists(path)
def __getitem__(self, key):
path = self._get_path(key)
if os.path.exists(path):
with open(path, "rb") as fh:
pickled = fh.read()
return self.decode(pickled)
else:
raise KeyError(key)
def __setitem__(self, key, value):
path = self._get_path(key)
pickled = self.encode(value)
try:
tname = path + "." + threading.current_thread().getName()
f = open(tname, "wb")
try:
f.write(pickled)
finally:
f.close()
shutil.move(tname, path) # atomary operation
except OSError:
pass
def __delitem__(self, key):
path = self._get_path(key)
if os.path.exists(path):
os.remove(path)
def cleanup(self, timeout):
if not os.path.isdir(self.root):
return
now = time.time()
for f in os.listdir(self.root):
path = self._get_path(f)
atime = os.stat(path).st_atime
if now - atime > timeout:
if os.path.isdir(path):
shutil.rmtree(path)
else:
os.remove(path)
class DBStore(Store):
"""Store for saving a session in database
Needs a table with the following columns:
session_id CHAR(128) UNIQUE NOT NULL,
atime DATETIME NOT NULL default current_timestamp,
data TEXT
"""
def __init__(self, db, table_name):
self.db = db
self.table = table_name
def __contains__(self, key):
data = self.db.select(self.table, where="session_id=$key", vars=locals())
return bool(list(data))
def __getitem__(self, key):
now = datetime.datetime.now()
try:
s = self.db.select(self.table, where="session_id=$key", vars=locals())[0]
self.db.update(
self.table, where="session_id=$key", atime=now, vars=locals()
)
except IndexError:
raise KeyError(key)
else:
return self.decode(s.data)
def __setitem__(self, key, value):
# Remove the leading `b` of bytes object (`b"..."`), otherwise encoded
# value is invalid base64 format.
pickled = self.encode(value).decode()
now = datetime.datetime.now()
if key in self:
self.db.update(
self.table,
where="session_id=$key",
data=pickled,
atime=now,
vars=locals(),
)
else:
self.db.insert(self.table, False, session_id=key, atime=now, data=pickled)
def __delitem__(self, key):
self.db.delete(self.table, where="session_id=$key", vars=locals())
def cleanup(self, timeout):
timeout = datetime.timedelta(
timeout / (24.0 * 60 * 60)
) # timedelta takes numdays as arg
last_allowed_time = datetime.datetime.now() - timeout
self.db.delete(self.table, where="$last_allowed_time > atime", vars=locals())
class ShelfStore:
"""Store for saving session using `shelve` module.
import shelve
store = ShelfStore(shelve.open('session.shelf'))
XXX: is shelve thread-safe?
"""
def __init__(self, shelf):
self.shelf = shelf
def __contains__(self, key):
return key in self.shelf
def __getitem__(self, key):
atime, v = self.shelf[key]
self[key] = v # update atime
return v
def __setitem__(self, key, value):
self.shelf[key] = time.time(), value
def __delitem__(self, key):
try:
del self.shelf[key]
except KeyError:
pass
def cleanup(self, timeout):
now = time.time()
for k in self.shelf:
atime, v = self.shelf[k]
if now - atime > timeout:
del self[k]
class MemoryStore(Store):
"""Store for saving a session in memory.
Useful where there is limited fs writes on the disk, like
flash memories
Data will be saved into a dict:
k: (time, pydata)
"""
def __init__(self, d_store=None):
if d_store is None:
d_store = {}
self.d_store = d_store
def __contains__(self, key):
return key in self.d_store
def __getitem__(self, key):
"""Return the value and update the last seen value"""
t, value = self.d_store[key]
self.d_store[key] = (time.time(), value)
return value
def __setitem__(self, key, value):
self.d_store[key] = (time.time(), value)
def __delitem__(self, key):
del self.d_store[key]
def cleanup(self, timeout):
now = time.time()
to_del = []
for k, (atime, value) in iteritems(self.d_store):
if now - atime > timeout:
to_del.append(k)
# to avoid exception on "dict change during iterations"
for k in to_del:
del self.d_store[k]
if __name__ == "__main__":
import doctest
doctest.testmod()