Refactor LDAP support and add LDAP caching

This commit is contained in:
PapaTutuWawa 2020-11-06 20:55:04 +01:00
parent 1fef1e2b7a
commit b0d0f99492
6 changed files with 98 additions and 95 deletions

View File

@ -79,33 +79,5 @@ class AppSettings:
def CHALLENGE_VALID_SECONDS(self): # pylint: disable=invalid-name
return self._setting("CHALLENGE_VALID_SECONDS", 60)
@cached_property
def USE_LDAP(self): # pylint: disable=invalid-name
return self._setting("USE_LDAP", False)
@cached_property
def LDAP_FILTER(self): # pylint: disable=invalid-name
return self._setting("LDAP_FILTER", "")
@cached_property
def LDAP_SEARCH_BASE(self): # pylint: disable=invalid-name
return self._setting("LDAP_SEARCH_BASE", "")
@cached_property
def LDAP_SERVER(self): # pylint: disable=invalid-name
return self._setting("LDAP_SERVER", "")
@cached_property
def LDAP_BIND_DN(self): # pylint: disable=invalid-name
return self._setting("LDAP_BIND_DN", "")
@cached_property
def LDAP_BIND_PASSWORD(self): # pylint: disable=invalid-name
return self._setting("LDAP_BIND_PW", "")
@cached_property
def LDAP_SEARCH_BASE(self): # pylint: disable=invalid-name
return self._setting("LDAP_SEARCH_BASE", "")
app_settings = AppSettings('ETEBASE_')

View File

@ -1,45 +0,0 @@
import logging
from . import app_settings
import ldap
class LDAPConnection:
__instance__ = None
@staticmethod
def get_instance():
'''To get a Singleton'''
if not LDAPConnection.__instance__:
return LDAPConnection()
else:
return LDAPConnection.__instance__
def __init__(self):
# Pull settings from django.conf.settings
# NOTE: We assume that settings.USE_LDAP is True
self.__ldap_connection = ldap.initialize(app_settings.LDAP_SERVER)
try:
self.__ldap_connection.simple_bind_s(app_settings.LDAP_BIND_DN,
app_settings.LDAP_BIND_PASSWORD)
except ldap.LDAPError as err:
logging.error(f'LDAP Error occuring during initialization: {err.desc}')
def has_user(self, username):
'''
Since we don't care about the password and so authentication
another way, all we care about is whether the user exists.
'''
filterstr = app_settings.LDAP_FILTER.replace('%s', username)
try:
result = self.__ldap_connection.search_s(app_settings.LDAP_SEARCH_BASE,
ldap.SCOPE_SUBTREE,
filterstr=filterstr)
except ldap.NO_RESULTS_RETURNED:
# We handle the specific error first and the the generic error, as
# we may expect ldap.NO_RESULTS_RETURNED, but not any other error
return False
except ldap.LDAPError as err:
logging.error(f'Error occured while performing an LDAP query: {err.desc}')
return False
return len(result) == 1

View File

@ -1,15 +1,11 @@
from django.utils import timezone
from django.utils.translation import gettext_lazy as _
from .. import app_settings
from rest_framework import exceptions
from rest_framework.authentication import TokenAuthentication as DRFTokenAuthentication
from .models import AuthToken, get_default_expiry
if app_settings.USE_LDAP:
from ..ldap import LDAPConnection
AUTO_REFRESH = True
MIN_REFRESH_INTERVAL = 60
@ -26,10 +22,6 @@ class TokenAuthentication(DRFTokenAuthentication):
except model.DoesNotExist:
raise exceptions.AuthenticationFailed(msg)
if app_settings.USE_LDAP:
if not LDAPConnection.get_instance().has_user(token.user.username):
raise exceptions.AuthenticationFailed('User is not listed in the LDAP registry.')
if not token.user.is_active:
raise exceptions.AuthenticationFailed(_('User inactive or deleted.'))

View File

@ -2,7 +2,6 @@ from django.contrib.auth import get_user_model
from django.core.exceptions import PermissionDenied
from . import app_settings
from .ldap import LDAPConnection
User = get_user_model()
@ -16,11 +15,6 @@ def get_user_queryset(queryset, view):
def create_user(*args, **kwargs):
# Check if the LDAP query returns exactly one user
if app_settings.USE_LDAP:
if not LDAPConnection.get_instance().has_user(kwargs['username']):
raise PermissionDenied('User is not listed in the LDAP registry.')
custom_func = app_settings.CREATE_USER_FUNC
if custom_func is not None:
return custom_func(*args, **kwargs)

View File

@ -166,14 +166,11 @@ if any(os.path.isfile(x) for x in config_locations):
if 'ldap' in config:
ldap = config['ldap']
ETEBASE_USE_LDAP = True
ETEBASE_LDAP_SERVER = ldap.get('server', '')
ETEBASE_LDAP_SEARCH_BASE = ldap.get('search_base', '')
ETEBASE_LDAP_FILTER = ldap.get('filter', '')
ETEBASE_LDAP_BIND_DN = ldap.get('bind_dn', '')
ETEBASE_LDAP_BIND_PW = ldap.get('bind_pw', '')
else:
ETEBASE_USE_LDAP = False
LDAP_SERVER = ldap.get('server', '')
LDAP_SEARCH_BASE = ldap.get('search_base', '')
LDAP_FILTER = ldap.get('filter', '')
LDAP_BIND_DN = ldap.get('bind_dn', '')
LDAP_BIND_PW = ldap.get('bind_pw', '')
ETEBASE_API_PERMISSIONS = ('rest_framework.permissions.IsAuthenticated', )
ETEBASE_API_AUTHENTICATORS = ('django_etebase.token_auth.authentication.TokenAuthentication',

93
myauth/ldap.py Normal file
View File

@ -0,0 +1,93 @@
import logging
from django.utils import timezone
from django.conf import settings
from django.core.exceptions import PermissionDenied
from rest_framework.permissions import BasePermission
import ldap
def ldap_setting(name, default):
'''Wrapper around django.conf.settings'''
return getattr(settings, f'LDAP_{name}', default)
class LDAPConnection:
__instance__ = None
__user_cache = {} # Username -> Valid until
@staticmethod
def get_instance():
'''To get a Singleton'''
if not LDAPConnection.__instance__:
return LDAPConnection()
else:
return LDAPConnection.__instance__
def __init__(self):
# Cache some settings
self.__LDAP_FILTER = ldap_setting('FILTER', '')
self.__LDAP_SEARCH_BASE = ldap_setting('SEARCH_BASE', '')
self.__ldap_connection = ldap.initialize(ldap_setting('SERVER', ''))
try:
self.__ldap_connection.simple_bind_s(ldap_setting('BIND_DN', ''),
ldap_setting('BIND_PW', ''))
except ldap.LDAPError as err:
logging.error(f'LDAP Error occuring during bind: {err.desc}')
def __is_cache_valid(self, username):
'''Returns True if the cache entry is still valid. Returns False otherwise.'''
if username in self.__user_cache:
if timezone.now() <= self.__user_cache[username]:
# Cache entry is still valid
return True
return False
def __remove_cache(self, username):
del self.__user_cache[username]
def has_user(self, username):
'''
Since we don't care about the password and so authentication
another way, all we care about is whether the user exists.
'''
if self.__is_cache_valid(username):
return True
if username in self.__user_cache:
self.__remove_cache(username)
filterstr = self.__LDAP_FILTER.replace('%s', username)
try:
result = self.__ldap_connection.search_s(self.__LDAP_SEARCH_BASE,
ldap.SCOPE_SUBTREE,
filterstr=filterstr)
except ldap.NO_RESULTS_RETURNED:
# We handle the specific error first and the the generic error, as
# we may expect ldap.NO_RESULTS_RETURNED, but not any other error
return False
except ldap.LDAPError as err:
logging.error(f'Error occured while performing an LDAP query: {err.desc}')
return False
if len(result) == 1:
self.__user_cache[username] = timezone.now() + timezone.timedelta(hours=1)
return True
return False
class LDAPUserExists(BasePermission):
'''
A permission check which first checks with the LDAP directory if the user
exists.
'''
def has_permission(self, request, view):
return LDAPConnection.get_instance().has_user(request.user.username):
def create_user(*args, **kwargs):
'''
A create_user function which first checks if the user already exists in the
configured LDAP directory.
'''
if not LDAPConnection.get_instance().has_user(kwargs['username']):
raise PermissionDenied('User not in the LDAP directory.')
return User.objects.create_user(*args, **kwargs)