import base64 import hashlib import random import ldap3 import logging from django.conf import settings logger = logging.getLogger(__name__) class LdapManager: __instance = None def __new__(cls): if LdapManager.__instance is None: LdapManager.__instance = object.__new__(cls) return LdapManager.__instance def __init__(self): """ Initialize the LDAP subsystem. """ self.rng = random.SystemRandom() self.server = ldap3.Server(settings.AUTH_LDAP_SERVER) def get_admin_conn(self): """ Return a bound :class:`ldap3.Connection` instance which has write permissions on the dn in which the user accounts reside. """ conn = self.get_conn(user=settings.LDAP_ADMIN_DN, password=settings.LDAP_ADMIN_PASSWORD, raise_exceptions=True) conn.bind() return conn def get_conn(self, **kwargs): """ Return an unbound :class:`ldap3.Connection` which talks to the configured LDAP server. The *kwargs* are passed to the constructor of :class:`ldap3.Connection` and can be used to set *user*, *password* and other useful arguments. """ return ldap3.Connection(self.server, **kwargs) def _ssha_password(self, password): """ Apply the SSHA password hashing scheme to the given *password*. *password* must be a :class:`bytes` object, containing the utf-8 encoded password. Return a :class:`bytes` object containing ``ascii``-compatible data which can be used as LDAP value, e.g. after armoring it once more using base64 or decoding it to unicode from ``ascii``. """ SALT_BYTES = 15 sha1 = hashlib.sha1() salt = self.rng.getrandbits(SALT_BYTES * 8).to_bytes(SALT_BYTES, "little") sha1.update(password) sha1.update(salt) digest = sha1.digest() passwd = b"{SSHA}" + base64.b64encode(digest + salt) return passwd def create_user(self, user, password, firstname, lastname, email): conn = self.get_admin_conn() uidNumber = self._get_max_uid() + 1 logger.debug("uidNumber={uidNumber}".format(uidNumber=uidNumber)) user_exists = True while user_exists: user_exists, _ = self.check_user_exists( "", '(&(objectClass=inetOrgPerson)(objectClass=posixAccount)' '(objectClass=top)(uidNumber={uidNumber}))'.format( uidNumber=uidNumber ) ) if user_exists: logger.debug( "{uid} exists. Trying next.".format(uid=uidNumber) ) uidNumber += 1 logger.debug("{uid} does not exist. Using it".format(uid=uidNumber)) self._set_max_uid(uidNumber) try: uid = user conn.add("uid={uid},{customer_dn}".format( uid=uid, customer_dn=settings.LDAP_CUSTOMER_DN ), ["inetOrgPerson", "posixAccount", "ldapPublickey"], { "uid": [uid], "sn": [lastname.encode("utf-8")], "givenName": [firstname.encode("utf-8")], "cn": [uid], "displayName": ["{} {}".format(firstname, lastname).encode("utf-8")], "uidNumber": [str(uidNumber)], "gidNumber": [str(settings.LDAP_CUSTOMER_GROUP_ID)], "loginShell": ["/bin/bash"], "homeDirectory": ["/home/{}".format(user).encode("utf-8")], "mail": email.encode("utf-8"), "userPassword": [self._ssha_password( password.encode("utf-8") )] } ) logger.debug('Created user %s %s' % (user.encode('utf-8'), uidNumber)) except Exception as ex: logger.debug('Could not create user %s' % user.encode('utf-8')) logger.error("Exception: " + str(ex)) raise Exception(ex) finally: conn.unbind() def change_password(self, uid, new_password): """ Changes the password of the user identified by user_dn :param uid: str The uid that identifies the user :param new_password: str The new password string :return: True if password was changed successfully False otherwise """ conn = self.get_admin_conn() # Make sure the user exists first to change his/her details user_exists, entries = self.check_user_exists( uid=uid, search_base=settings.ENTIRE_SEARCH_BASE ) return_val = False if user_exists: try: return_val = conn.modify( entries[0].entry_dn, { "userpassword": ( ldap3.MODIFY_REPLACE, [self._ssha_password(new_password.encode("utf-8"))] ) } ) except Exception as ex: logger.error("Exception: " + str(ex)) else: logger.error("User {} not found".format(uid)) conn.unbind() return return_val def change_user_details(self, uid, details): """ Updates the user details as per given values in kwargs of the user identified by user_dn. Assumes that all attributes passed in kwargs are valid. :param uid: str The uid that identifies the user :param details: dict A dictionary containing the new values :return: True if user details were updated successfully False otherwise """ conn = self.get_admin_conn() # Make sure the user exists first to change his/her details user_exists, entries = self.check_user_exists( uid=uid, search_base=settings.ENTIRE_SEARCH_BASE ) return_val = False if user_exists: details_dict = {k: (ldap3.MODIFY_REPLACE, [v.encode("utf-8")]) for k, v in details.items()} try: return_val = conn.modify(entries[0].entry_dn, details_dict) msg = "success" except Exception as ex: msg = str(ex) logger.error("Exception: " + msg) finally: conn.unbind() else: msg = "User {} not found".format(uid) logger.error(msg) conn.unbind() return return_val, msg def check_user_exists(self, uid, search_filter="", attributes=None, search_base=settings.LDAP_CUSTOMER_DN, search_attr="uid"): """ Check if the user with the given uid exists in the customer group. :param uid: str representing the user :param search_filter: str representing the filter condition to find users. If its empty, the search finds the user with the given uid. :param attributes: list A list of str representing all the attributes to be obtained in the result entries :param search_base: str :return: tuple (bool, [ldap3.abstract.entry.Entry ..]) A bool indicating if the user exists A list of all entries obtained in the search """ conn = self.get_admin_conn() entries = [] try: result = conn.search( search_base=search_base, search_filter=search_filter if len(search_filter) > 0 else '(uid={uid})'.format(uid=uid), attributes=attributes ) entries = conn.entries finally: conn.unbind() return result, entries def delete_user(self, uid): """ Deletes the user with the given uid from ldap :param uid: str representing the user :return: True if the delete was successful False otherwise """ conn = self.get_admin_conn() try: return_val = conn.delete( ("uid={uid}," + settings.LDAP_CUSTOMER_DN).format(uid=uid), ) msg = "success" except Exception as ex: msg = str(ex) logger.error("Exception: " + msg) return_val = False finally: conn.unbind() return return_val, msg def _set_max_uid(self, max_uid): """ a utility function to save max_uid value to a file :param max_uid: an integer representing the max uid :return: """ with open(settings.LDAP_MAX_UID_FILE_PATH, 'w+') as handler: handler.write(str(max_uid)) def _get_max_uid(self): """ A utility function to read the max uid value that was previously set :return: An integer representing the max uid value that was previously set """ try: with open(settings.LDAP_MAX_UID_FILE_PATH, 'r+') as handler: try: return_value = int(handler.read()) except ValueError as ve: logger.error( "Error reading int value from {}. {}" "Returning default value {} instead".format( settings.LDAP_MAX_UID_PATH, str(ve), settings.LDAP_DEFAULT_START_UID ) ) return_value = settings.LDAP_DEFAULT_START_UID return return_value except FileNotFoundError as fnfe: logger.error("File not found : " + str(fnfe)) return_value = settings.LDAP_DEFAULT_START_UID logger.error("So, returning UID={}".format(return_value)) return return_value