import smtplib import textwrap from typing import Iterable, List, Set, Union from asgiref.sync import async_to_sync from django.conf import settings from django.contrib.auth import ( login as auth_login, logout as auth_logout, update_session_auth_hash, ) from django.contrib.auth.forms import AuthenticationForm from django.contrib.auth.models import Permission from django.contrib.auth.password_validation import validate_password from django.contrib.auth.tokens import default_token_generator from django.contrib.sites.shortcuts import get_current_site from django.core import mail from django.core.exceptions import ValidationError as DjangoValidationError from django.db import transaction from django.http.request import QueryDict from django.utils.encoding import force_bytes, force_text from django.utils.http import urlsafe_base64_decode, urlsafe_base64_encode from openslides.saml import SAML_ENABLED from ..core.config import config from ..core.signals import permission_change from ..utils.auth import ( GROUP_ADMIN_PK, GROUP_DEFAULT_PK, anonymous_is_enabled, has_perm, ) from ..utils.autoupdate import Element, inform_changed_data, inform_changed_elements from ..utils.cache import element_cache from ..utils.rest_api import ( ModelViewSet, Response, SimpleMetadata, ValidationError, detail_route, list_route, status, ) from ..utils.validate import validate_json from ..utils.views import APIView from .access_permissions import ( GroupAccessPermissions, PersonalNoteAccessPermissions, UserAccessPermissions, ) from .models import Group, PersonalNote, User from .serializers import GroupSerializer, PermissionRelatedField from .user_backend import user_backend_manager # Viewsets for the REST API class UserViewSet(ModelViewSet): """ API endpoint for users. There are the following views: metadata, list, retrieve, create, partial_update, update, destroy and reset_password. """ access_permissions = UserAccessPermissions() queryset = User.objects.all() def check_view_permissions(self): """ Returns True if the user has required permissions. """ if self.action in ("list", "retrieve"): result = self.get_access_permissions().check_permissions(self.request.user) elif self.action == "metadata": result = has_perm(self.request.user, "users.can_see_name") elif self.action in ("update", "partial_update"): result = self.request.user.is_authenticated elif self.action in ( "create", "destroy", "reset_password", "bulk_generate_passwords", "bulk_reset_passwords_to_default", "bulk_set_state", "bulk_alter_groups", "bulk_delete", "mass_import", "mass_invite_email", ): result = ( has_perm(self.request.user, "users.can_see_name") and has_perm(self.request.user, "users.can_see_extra_data") and has_perm(self.request.user, "users.can_manage") ) else: result = False return result def update(self, request, *args, **kwargs): """ Customized view endpoint to update an user. Checks also whether the requesting user can update the user. He needs at least the permissions 'users.can_see_name' (see self.check_view_permissions()). Also it is evaluated whether he wants to update himself or is manager. """ user = self.get_object() # Check permissions. if ( has_perm(self.request.user, "users.can_see_name") and has_perm(request.user, "users.can_see_extra_data") and has_perm(request.user, "users.can_manage") ): # The user has all permissions so he may update every user. if request.data.get("is_active") is False and user == request.user: # But a user can not deactivate himself. raise ValidationError({"detail": "You can not deactivate yourself."}) else: # The user does not have all permissions so he may only update himself. if str(request.user.pk) != self.kwargs["pk"]: self.permission_denied(request) # This is a hack to make request.data mutable. Otherwise fields can not be deleted. if isinstance(request.data, QueryDict): request.data._mutable = True # Remove fields that the user is not allowed to change. # The list() is required because we want to use del inside the loop. for key in list(request.data.keys()): if key not in ("username", "about_me", "email"): del request.data[key] user_backend = user_backend_manager.get_backend(user.auth_type) if user_backend: disallowed_keys = user_backend.get_disallowed_update_keys() for key in list(request.data.keys()): if key in disallowed_keys: del request.data[key] # Hack to make the serializers validation work again if no username, last- or firstname is given: if ( "username" not in request.data and "first_name" not in request.data and "last_name" not in request.data ): request.data["username"] = user.username response = super().update(request, *args, **kwargs) return response def destroy(self, request, *args, **kwargs): """ Customized view endpoint to delete an user. Ensures that no one can delete himself. """ instance = self.get_object() if instance == self.request.user: raise ValidationError({"detail": "You can not delete yourself."}) self.perform_destroy(instance) return Response(status=status.HTTP_204_NO_CONTENT) @detail_route(methods=["post"]) def reset_password(self, request, pk=None): """ View to reset the password of the given user (by url) using a provided password. Expected data: { pasword: } """ user = self.get_object() if user.auth_type != "default": raise ValidationError( { "detail": "The user does not have the login information stored in OpenSlides" } ) password = request.data.get("password") if not isinstance(password, str): raise ValidationError({"detail": "Password has to be a string."}) try: validate_password(password, user=request.user) except DjangoValidationError as errors: raise ValidationError({"detail": " ".join(errors)}) user.set_password(password) user.save() return Response({"detail": "Password successfully reset."}) @list_route(methods=["post"]) def bulk_generate_passwords(self, request): """ Generates new random passwords for many users. The request user is excluded and the default password will be set to the new generated passwords. Expected data: { user_ids: } """ ids = request.data.get("user_ids") self.assert_list_of_ints(ids) # Exclude the request user users = self.bulk_get_users(request, ids) for user in users: password = User.objects.make_random_password() user.set_password(password) user.default_password = password user.save() return Response() @list_route(methods=["post"]) def bulk_reset_passwords_to_default(self, request): """ resets the password of all given users to their default ones. The request user is excluded. Expected data: { user_ids: } """ ids = request.data.get("user_ids") self.assert_list_of_ints(ids) # Exclude the request user users = self.bulk_get_users(request, ids) # Validate all default passwords for user in users: try: validate_password(user.default_password, user=user) except DjangoValidationError as errors: errors = " ".join(errors) raise ValidationError( { "detail": 'The default password of user "{0}" is not valid: {1}', "args": [user.username, str(errors)], } ) # Reset passwords for user in users: user.set_password(user.default_password) user.save() return Response() @list_route(methods=["post"]) def bulk_set_state(self, request): """ Sets the "state" of may users. The "state" means boolean attributes like active or committee of a user. If 'is_active' is choosen, the request user will be removed from the list of user ids. Expected data: { user_ids: field: 'is_active' | 'is_present' | 'is_committee' value: True|False } """ ids = request.data.get("user_ids") self.assert_list_of_ints(ids) field = request.data.get("field") if field not in ("is_active", "is_present", "is_committee"): raise ValidationError({"detail": "Unsupported field"}) value = request.data.get("value") if not isinstance(value, bool): raise ValidationError({"detail": "value must be true or false"}) users = User.objects.filter(auth_type="default").filter(pk__in=ids) if field == "is_active": users = users.exclude(pk=request.user.id) for user in users: setattr(user, field, value) user.save() return Response() @list_route(methods=["post"]) def bulk_alter_groups(self, request): """ Adds or removes groups from given users. The request user is excluded. Expected data: { user_ids: , action: "add" | "remove", group_ids: } """ user_ids = request.data.get("user_ids") self.assert_list_of_ints(user_ids) group_ids = request.data.get("group_ids") self.assert_list_of_ints(group_ids, ids_name="groups_id") action = request.data.get("action") if action not in ("add", "remove"): raise ValidationError({"detail": "The action must be add or remove"}) users = self.bulk_get_users(request, user_ids) groups = list(Group.objects.filter(pk__in=group_ids)) for user in users: if action == "add": user.groups.add(*groups) else: user.groups.remove(*groups) inform_changed_data(users) return Response() @list_route(methods=["post"]) def bulk_delete(self, request): """ Deletes many users. The request user will be excluded. Expected data: { user_ids: } """ ids = request.data.get("user_ids") self.assert_list_of_ints(ids) # Exclude the request user users = self.bulk_get_users(request, ids) for user in list(users): user.delete() return Response(status=status.HTTP_204_NO_CONTENT) def bulk_get_users(self, request, ids): """ Get all users for the given ids. Exludes the request user and all users with a non-default auth_type. """ return ( User.objects.filter(auth_type="default") .exclude(pk=request.user.id) .filter(pk__in=ids) ) @list_route(methods=["post"]) @transaction.atomic def mass_import(self, request): """ API endpoint to create multiple users at once. Example: {"users": [{"first_name": "Max"}, {"first_name": "Maxi"}]} """ users = request.data.get("users") if not isinstance(users, list): raise ValidationError({"detail": "Users has to be a list."}) created_users = [] # List of all track ids of all imported users. The track ids are just used in the client. imported_track_ids = [] for user in users: serializer = self.get_serializer(data=user) try: serializer.is_valid(raise_exception=True) except ValidationError: # Skip invalid users. continue data = serializer.prepare_password(serializer.data) groups = data["groups_id"] del data["groups_id"] db_user = User(**data) db_user.save(skip_autoupdate=True) db_user.groups.add(*groups) created_users.append(db_user) if "importTrackId" in user: imported_track_ids.append(user["importTrackId"]) # Now inform all clients and send a response inform_changed_data(created_users) return Response( { "detail": "{0} users successfully imported.", "args": [len(created_users)], "importedTrackIds": imported_track_ids, } ) @list_route(methods=["post"]) def mass_invite_email(self, request): """ Endpoint to send invitation emails to all given users (by id). Returns the number of emails send. """ user_ids = request.data.get("user_ids") self.assert_list_of_ints(user_ids) # Get subject and body from the response. Do not use the config values # because they might not be translated. subject = request.data.get("subject") message = request.data.get("message") if not isinstance(subject, str): raise ValidationError({"detail": "Subject has to be a string."}) if not isinstance(message, str): raise ValidationError({"detail": "Message has to be a string."}) users = User.objects.filter(pk__in=user_ids) # Sending Emails. Keep track, which users gets an email. # First, try to open the connection to the smtp server. connection = mail.get_connection(fail_silently=False) try: connection.open() except ConnectionRefusedError: raise ValidationError( { "detail": "Cannot connect to SMTP server on {0}:{1}", "args": [settings.EMAIL_HOST, settings.EMAIL_PORT], } ) except smtplib.SMTPException as err: raise ValidationError({"detail": f"{err.errno}: {err.strerror}"}) success_users = [] user_pks_without_email = [] try: for user in users: if user.email: if user.send_invitation_email( connection, subject, message, skip_autoupdate=True ): success_users.append(user) else: user_pks_without_email.append(user.pk) except DjangoValidationError as err: raise ValidationError(err.message_dict) connection.close() inform_changed_data(success_users) return Response( {"count": len(success_users), "no_email_ids": user_pks_without_email} ) def assert_list_of_ints(self, ids, ids_name="user_ids"): """ Asserts, that ids is a list of ints. Raises a ValidationError, if not. """ if not isinstance(ids, list): raise ValidationError({"detail": "{0} must be a list", "args": [ids_name]}) for id in ids: if not isinstance(id, int): raise ValidationError({"detail": "Every id must be a int"}) class GroupViewSetMetadata(SimpleMetadata): """ Customized metadata class for OPTIONS requests. """ def get_field_info(self, field): """ Customized method to change the display name of permission choices. """ field_info = super().get_field_info(field) if field.field_name == "permissions": field_info["choices"] = [ { "value": choice_value, "display_name": force_text(choice_name, strings_only=True).split( " | " )[2], } for choice_value, choice_name in field.choices.items() ] return field_info class GroupViewSet(ModelViewSet): """ API endpoint for groups. There are the following views: metadata, list, retrieve, create, partial_update, update and destroy. """ metadata_class = GroupViewSetMetadata queryset = Group.objects.all() serializer_class = GroupSerializer access_permissions = GroupAccessPermissions() def check_view_permissions(self): """ Returns True if the user has required permissions. """ if self.action in ("list", "retrieve"): result = self.get_access_permissions().check_permissions(self.request.user) elif self.action == "metadata": # Every authenticated user can see the metadata. # Anonymous users can do so if they are enabled. result = self.request.user.is_authenticated or anonymous_is_enabled() elif self.action in ( "create", "partial_update", "update", "destroy", "set_permission", ): # Users with all app permissions can edit groups. result = ( has_perm(self.request.user, "users.can_see_name") and has_perm(self.request.user, "users.can_see_extra_data") and has_perm(self.request.user, "users.can_manage") ) else: # Deny request in any other case. result = False return result def update(self, request, *args, **kwargs): """ Customized endpoint to update a group. Send the signal 'permission_change' if group permissions change. """ group = self.get_object() # Collect old and new (given) permissions to get the difference. old_permissions = list( group.permissions.all() ) # Force evaluation so the perms don't change anymore. permission_names = request.data["permissions"] if isinstance(permission_names, str): permission_names = [permission_names] given_permissions = [ PermissionRelatedField(read_only=True).to_internal_value(data=perm) for perm in permission_names ] # Run super to update the group. response = super().update(request, *args, **kwargs) # Check status code and send 'permission_change' signal. if response.status_code == 200: changed_permissions = list( set(old_permissions).symmetric_difference(set(given_permissions)) ) self.inform_permission_change(group, changed_permissions) return response def destroy(self, request, *args, **kwargs): """ Protects builtin groups 'Default' (pk=1) and 'Admin' (pk=2) from being deleted. """ instance = self.get_object() if instance.pk in (GROUP_DEFAULT_PK, GROUP_ADMIN_PK): self.permission_denied(request) # The list() is required to evaluate the query affected_users_ids = list(instance.user_set.values_list("pk", flat=True)) # Delete the group self.perform_destroy(instance) # Get the updated user data from the DB. affected_users = User.objects.filter(pk__in=affected_users_ids) inform_changed_data(affected_users) return Response(status=status.HTTP_204_NO_CONTENT) @detail_route(methods=["post"]) @transaction.atomic def set_permission(self, request, *args, **kwargs): """ Send {perm: , set: } to set or remove the permission from a group """ perm = request.data.get("perm") if not isinstance(perm, str): raise ValidationError("You have to give a permission as string.") set = request.data.get("set") if not isinstance(set, bool): raise ValidationError("You have to give a set value.") # check if perm is a valid permission try: app_label, codename = perm.split(".") except ValueError: raise ValidationError("Incorrect permission string") try: permission = Permission.objects.get( content_type__app_label=app_label, codename=codename ) except Permission.DoesNotExist: raise ValidationError("Incorrect permission string") # add/remove the permission group = self.get_object() if set: group.permissions.add(permission) else: group.permissions.remove(permission) self.inform_permission_change(group, permission) inform_changed_data(group) return Response( { "detail": "Permissions of group {0} successfully changed.", "args": [group.pk], } ) def inform_permission_change( self, group: Group, changed_permissions: Union[None, Permission, Iterable[Permission]], ) -> None: """ Updates every users, if some permission changes. For this, every affected collection is fetched via the permission_change signal and every object of the collection passed into the cache/autoupdate system. Also the personal (restrcited) cache of every affected user (all users of the group) will be deleted, so it is rebuild after this permission change. """ if isinstance(changed_permissions, Permission): changed_permissions = [changed_permissions] if not changed_permissions: return # either None or empty list. elements: List[Element] = [] signal_results = permission_change.send(None, permissions=changed_permissions) all_full_data = async_to_sync(element_cache.get_all_data_list)() for _, signal_collections in signal_results: for cachable in signal_collections: for full_data in all_full_data.get( cachable.get_collection_string(), {} ): elements.append( Element( id=full_data["id"], collection_string=cachable.get_collection_string(), full_data=full_data, disable_history=True, ) ) inform_changed_elements(elements) class PersonalNoteViewSet(ModelViewSet): """ API endpoint for personal notes. There are the following views: metadata, list, retrieve, create, partial_update, update, and destroy. """ access_permissions = PersonalNoteAccessPermissions() queryset = PersonalNote.objects.all() def check_view_permissions(self): """ Returns True if the user has required permissions. """ if self.action in ("list", "retrieve"): result = self.get_access_permissions().check_permissions(self.request.user) elif self.action in ("create_or_update", "destroy"): # Every authenticated user can see metadata and create personal # notes for himself and can manipulate only his own personal notes. # See self.perform_create(), self.update() and self.destroy(). result = self.request.user.is_authenticated else: result = False return result @list_route(methods=["post"]) @transaction.atomic def create_or_update(self, request, *args, **kwargs): """ Customized method to ensure that every user can change only his own personal notes. [{ collection: , id: , content: , }, ...] """ # verify data: if not isinstance(request.data, list): raise ValidationError({"detail": "Data must be a list"}) for data in request.data: if not isinstance(data, dict): raise ValidationError({"detail": "Every entry must be a dict"}) if not isinstance(data.get("collection"), str): raise ValidationError({"detail": "The collection must be a string"}) if not isinstance(data.get("id"), int): raise ValidationError({"detail": "The id must be an integer"}) # get note personal_note, _ = PersonalNote.objects.get_or_create(user=request.user) # set defaults if not personal_note.notes: personal_note.notes = {} for data in request.data: if data["collection"] not in personal_note.notes: personal_note.notes[data["collection"]] = {} content = validate_json(data["content"], 2) personal_note.notes[data["collection"]][data["id"]] = content personal_note.save() return Response() def destroy(self, request, *args, **kwargs): """ Customized method to ensure that every user can delete only his own personal notes. """ if self.get_object().user != self.request.user: self.permission_denied(request) return super().destroy(request, *args, **kwargs) # Special API views class WhoAmIDataView(APIView): def get_whoami_data(self): """ Appends the user id to the context. Uses None for the anonymous user. Appends also a flag if guest users are enabled in the config. Appends also the serialized user if available and auth_type. """ user_id = self.request.user.pk or 0 guest_enabled = anonymous_is_enabled() auth_type = "default" if user_id: user_full_data = async_to_sync(element_cache.get_element_data)( self.request.user.get_collection_string(), user_id ) auth_type = user_full_data["auth_type"] user_data = async_to_sync(element_cache.restrict_element_data)( user_full_data, self.request.user.get_collection_string(), user_id ) group_ids = user_data["groups_id"] or [GROUP_DEFAULT_PK] else: user_data = None group_ids = [GROUP_DEFAULT_PK] if guest_enabled else [] # collect all permissions permissions: Set[str] = set() group_all_data = async_to_sync(element_cache.get_collection_data)("users/group") for group_id in group_ids: permissions.update(group_all_data[group_id]["permissions"]) return { "user_id": user_id or None, "guest_enabled": guest_enabled, "user": user_data, "auth_type": auth_type, "permissions": list(permissions), } def get_context_data(self, **context): context.update(self.get_whoami_data()) return super().get_context_data(**context) class UserLoginView(WhoAmIDataView): """ Login the user. """ http_method_names = ["get", "post"] def post(self, *args, **kwargs): # If the client tells that cookies are disabled, do not continue as guest (if enabled) if not self.request.data.get("cookies", True): raise ValidationError( {"detail": "Cookies have to be enabled to use OpenSlides."} ) form = AuthenticationForm(self.request, data=self.request.data) if not form.is_valid(): raise ValidationError({"detail": "Username or password is not correct."}) self.user = form.get_user() if self.user.auth_type != "default": raise ValidationError({"detail": "Please login via your identity provider"}) auth_login(self.request, self.user) return super().post(*args, **kwargs) def get_context_data(self, **context): """ Adds some context. For GET requests adds login info text to context. This info text is taken from the config. If this value is empty, a special text is used if the admin user has the password 'admin'. For POST requests adds the id of the current user to the context. """ if self.request.method == "GET": if config["general_login_info_text"]: context["login_info_text"] = config["general_login_info_text"] else: try: user = User.objects.get(username="admin") if user.check_password("admin"): context["login_info_text"] = ( f"Use admin and admin for your first login.
" "Please change your password to hide this message!" ) except User.DoesNotExist: pass # Add the privacy policy and legal notice, so the client can display it # even, it is not logged in. context["privacy_policy"] = config["general_event_privacy_policy"] context["legal_notice"] = config["general_event_legal_notice"] # Add the theme, so the loginpage is themed correctly context["theme"] = config["openslides_theme"] context["logo_web_header"] = config["logo_web_header"] if SAML_ENABLED: from openslides.saml.settings import get_saml_settings context["saml_settings"] = get_saml_settings().general_settings else: # self.request.method == 'POST' context.update(self.get_whoami_data()) return super().get_context_data(**context) class UserLogoutView(WhoAmIDataView): """ Logout the user. """ http_method_names = ["post"] def post(self, *args, **kwargs): if not self.request.user.is_authenticated: raise ValidationError({"detail": "You are not authenticated."}) auth_logout(self.request) return super().post(*args, **kwargs) class WhoAmIView(WhoAmIDataView): """ Returns the id of the requesting user. """ http_method_names = ["get"] class SetPasswordView(APIView): """ Users can set a new password for themselves. """ http_method_names = ["post"] def post(self, request, *args, **kwargs): user = request.user if ( not user.is_authenticated or not has_perm(user, "users.can_change_password") or user.auth_type != "default" ): self.permission_denied(request) if user.check_password(request.data["old_password"]): try: validate_password(request.data.get("new_password"), user=user) except DjangoValidationError as errors: raise ValidationError({"detail": " ".join(errors)}) user.set_password(request.data["new_password"]) user.save() update_session_auth_hash(request, user) else: raise ValidationError({"detail": "Old password does not match."}) return super().post(request, *args, **kwargs) class PasswordResetView(APIView): """ Users can send an email to themselves to get a password reset email. Send POST request with {'email': } and all users with this address will receive an email (means Django sends one or more emails to this address) with a one-use only link. """ http_method_names = ["post"] use_https = True # TODO: get used protocol from server, see issue #4233 def post(self, request, *args, **kwargs): """ Loop over all users and send emails. """ to_email = request.data.get("email") users = self.get_users(to_email) if len(users) == 0 and getattr(settings, "RESET_PASSWORD_VERBOSE_ERRORS", True): raise ValidationError( {"detail": "No users with email {0} found.", "args": [to_email]} ) for user in users: current_site = get_current_site(request) site_name = current_site.name if has_perm(user, "users.can_change_password") or has_perm( user, "users.can_manage" ): context = { "email": to_email, "site_name": site_name, "protocol": "https" if self.use_https else "http", "domain": current_site.domain, "path": "/login/reset-password-confirm/", "user_id": urlsafe_base64_encode( force_bytes(user.pk) ), # urlsafe_base64_encode decodes to ascii "token": default_token_generator.make_token(user), "username": user.get_username(), } body = self.get_email_body(**context) else: # User is not allowed to reset his permission. Send only short message. body = f""" You do not have permission to reset your password at {site_name}. Please contact your local administrator. Your username, in case you've forgotten: {user.get_username()} """ # Send a django.core.mail.EmailMessage to `to_email`. subject = f"Password reset for {site_name}" subject = "".join(subject.splitlines()) from_email = None # TODO: Add nice from_email here. email_message = mail.EmailMessage(subject, body, from_email, [to_email]) try: email_message.send() except smtplib.SMTPRecipientsRefused: raise ValidationError( { "detail": "Error: The email to {0} was refused by the server. Please contact your local administrator.", "args": [to_email], } ) except smtplib.SMTPAuthenticationError as e: # Nice error message on auth failure raise ValidationError( { "detail": "Error {0}: Authentication failure. Please contact your administrator.", "args": [e.smtp_code], } ) except ConnectionRefusedError: raise ValidationError( { "detail": "Connection refused error. Please contact your administrator." } ) return Response() def get_users(self, email): """Given an email, return matching user(s) who should receive a reset. This allows subclasses to more easily customize the default policies that prevent inactive users and users with unusable passwords from resetting their password. """ active_users = User.objects.filter( **{"email__iexact": email, "is_active": True, "auth_type": "default"} ) return [u for u in active_users if u.has_usable_password()] def get_email_body(self, **context): """ Add context to email template and return the complete body. """ return textwrap.dedent( """ You're receiving this email because you requested a password reset for your user account at {site_name}. Please go to the following page and choose a new password: {protocol}://{domain}{path}?user_id={user_id}&token={token} Your username, in case you've forgotten: {username} Thanks for using our site! The {site_name} team. """ ).format(**context) class PasswordResetConfirmView(APIView): """ View to reset the password. Send POST request with {'user_id': , 'token': , 'password' } to set password of this user to the new one. """ http_method_names = ["post"] def post(self, request, *args, **kwargs): uidb64 = request.data.get("user_id") token = request.data.get("token") password = request.data.get("password") if not (uidb64 and token and password): raise ValidationError( {"detail": "You have to provide user_id, token and password."} ) user = self.get_user(uidb64) if user is None: raise ValidationError({"detail": "User does not exist."}) if not ( has_perm(user, "users.can_change_password") or has_perm(user, "users.can_manage") ): self.permission_denied(request) if not default_token_generator.check_token(user, token): raise ValidationError({"detail": "Invalid token."}) try: validate_password(password, user=user) except DjangoValidationError as errors: raise ValidationError({"detail": " ".join(errors)}) user.set_password(password) user.save() return super().post(request, *args, **kwargs) def get_user(self, uidb64): try: # urlsafe_base64_decode() decodes to bytestring uid = urlsafe_base64_decode(uidb64).decode() user = User.objects.get(pk=uid) except (TypeError, ValueError, OverflowError, User.DoesNotExist): user = None return user