from urllib.parse import urlparse, urlunparse from django.conf import settings # Avoid shadowing the login() and logout() views below. from django.contrib.auth import ( REDIRECT_FIELD_NAME, get_user_model, login as auth_login, logout as auth_logout, update_session_auth_hash, ) from django.contrib.auth.decorators import login_required from django.contrib.auth.forms import ( AuthenticationForm, PasswordChangeForm, PasswordResetForm, SetPasswordForm, ) from django.contrib.auth.tokens import default_token_generator from django.contrib.sites.shortcuts import get_current_site from django.core.exceptions import ValidationError from django.http import HttpResponseRedirect, QueryDict from django.shortcuts import resolve_url from django.urls import reverse_lazy from django.utils.decorators import method_decorator from django.utils.http import ( url_has_allowed_host_and_scheme, urlsafe_base64_decode, ) from django.utils.translation import gettext_lazy as _ from django.views.decorators.cache import never_cache from django.views.decorators.csrf import csrf_protect from django.views.decorators.debug import sensitive_post_parameters from django.views.generic.base import TemplateView from django.views.generic.edit import FormView UserModel = get_user_model() class SuccessURLAllowedHostsMixin: success_url_allowed_hosts = set() def get_success_url_allowed_hosts(self): return {self.request.get_host(), *self.success_url_allowed_hosts} class LoginView(SuccessURLAllowedHostsMixin, FormView): """ Display the login form and handle the login action. """ form_class = AuthenticationForm authentication_form = None redirect_field_name = REDIRECT_FIELD_NAME template_name = 'registration/login.html' redirect_authenticated_user = False extra_context = None @method_decorator(sensitive_post_parameters()) @method_decorator(csrf_protect) @method_decorator(never_cache) def dispatch(self, request, *args, **kwargs): if self.redirect_authenticated_user and self.request.user.is_authenticated: redirect_to = self.get_success_url() if redirect_to == self.request.path: raise ValueError( "Redirection loop for authenticated user detected. Check that " "your LOGIN_REDIRECT_URL doesn't point to a login page." ) return HttpResponseRedirect(redirect_to) return super().dispatch(request, *args, **kwargs) def get_success_url(self): url = self.get_redirect_url() return url or resolve_url(settings.LOGIN_REDIRECT_URL) def get_redirect_url(self): """Return the user-originating redirect URL if it's safe.""" redirect_to = self.request.POST.get( self.redirect_field_name, self.request.GET.get(self.redirect_field_name, '') ) url_is_safe = url_has_allowed_host_and_scheme( url=redirect_to, allowed_hosts=self.get_success_url_allowed_hosts(), require_https=self.request.is_secure(), ) return redirect_to if url_is_safe else '' def get_form_class(self): return self.authentication_form or self.form_class def get_form_kwargs(self): kwargs = super().get_form_kwargs() kwargs['request'] = self.request return kwargs def form_valid(self, form): """Security check complete. Log the user in.""" auth_login(self.request, form.get_user()) return HttpResponseRedirect(self.get_success_url()) def get_context_data(self, **kwargs): context = super().get_context_data(**kwargs) current_site = get_current_site(self.request) context.update({ self.redirect_field_name: self.get_redirect_url(), 'site': current_site, 'site_name': current_site.name, **(self.extra_context or {}) }) return context class LogoutView(SuccessURLAllowedHostsMixin, TemplateView): """ Log out the user and display the 'You are logged out' message. """ next_page = None redirect_field_name = REDIRECT_FIELD_NAME template_name = 'registration/logged_out.html' extra_context = None @method_decorator(never_cache) def dispatch(self, request, *args, **kwargs): auth_logout(request) next_page = self.get_next_page() if next_page: # Redirect to this page until the session has been cleared. return HttpResponseRedirect(next_page) return super().dispatch(request, *args, **kwargs) def post(self, request, *args, **kwargs): """Logout may be done via POST.""" return self.get(request, *args, **kwargs) def get_next_page(self): if self.next_page is not None: next_page = resolve_url(self.next_page) elif settings.LOGOUT_REDIRECT_URL: next_page = resolve_url(settings.LOGOUT_REDIRECT_URL) else: next_page = self.next_page if (self.redirect_field_name in self.request.POST or self.redirect_field_name in self.request.GET): next_page = self.request.POST.get( self.redirect_field_name, self.request.GET.get(self.redirect_field_name) ) url_is_safe = url_has_allowed_host_and_scheme( url=next_page, allowed_hosts=self.get_success_url_allowed_hosts(), require_https=self.request.is_secure(), ) # Security check -- Ensure the user-originating redirection URL is # safe. if not url_is_safe: next_page = self.request.path return next_page def get_context_data(self, **kwargs): context = super().get_context_data(**kwargs) current_site = get_current_site(self.request) context.update({ 'site': current_site, 'site_name': current_site.name, 'title': _('Logged out'), **(self.extra_context or {}) }) return context def logout_then_login(request, login_url=None): """ Log out the user if they are logged in. Then redirect to the login page. """ login_url = resolve_url(login_url or settings.LOGIN_URL) return LogoutView.as_view(next_page=login_url)(request) def redirect_to_login(next, login_url=None, redirect_field_name=REDIRECT_FIELD_NAME): """ Redirect the user to the login page, passing the given 'next' page. """ resolved_url = resolve_url(login_url or settings.LOGIN_URL) login_url_parts = list(urlparse(resolved_url)) if redirect_field_name: querystring = QueryDict(login_url_parts[4], mutable=True) querystring[redirect_field_name] = next login_url_parts[4] = querystring.urlencode(safe='/') return HttpResponseRedirect(urlunparse(login_url_parts)) # Class-based password reset views # - PasswordResetView sends the mail # - PasswordResetDoneView shows a success message for the above # - PasswordResetConfirmView checks the link the user clicked and # prompts for a new password # - PasswordResetCompleteView shows a success message for the above class PasswordContextMixin: extra_context = None def get_context_data(self, **kwargs): context = super().get_context_data(**kwargs) context.update({ 'title': self.title, **(self.extra_context or {}) }) return context class PasswordResetView(PasswordContextMixin, FormView): email_template_name = 'registration/password_reset_email.html' extra_email_context = None form_class = PasswordResetForm from_email = None html_email_template_name = None subject_template_name = 'registration/password_reset_subject.txt' success_url = reverse_lazy('password_reset_done') template_name = 'registration/password_reset_form.html' title = _('Password reset') token_generator = default_token_generator @method_decorator(csrf_protect) def dispatch(self, *args, **kwargs): return super().dispatch(*args, **kwargs) def form_valid(self, form): opts = { 'use_https': self.request.is_secure(), 'token_generator': self.token_generator, 'from_email': self.from_email, 'email_template_name': self.email_template_name, 'subject_template_name': self.subject_template_name, 'request': self.request, 'html_email_template_name': self.html_email_template_name, 'extra_email_context': self.extra_email_context, } form.save(**opts) return super().form_valid(form) INTERNAL_RESET_SESSION_TOKEN = '_password_reset_token' class PasswordResetDoneView(PasswordContextMixin, TemplateView): template_name = 'registration/password_reset_done.html' title = _('Password reset sent') class PasswordResetConfirmView(PasswordContextMixin, FormView): form_class = SetPasswordForm post_reset_login = False post_reset_login_backend = None reset_url_token = 'set-password' success_url = reverse_lazy('password_reset_complete') template_name = 'registration/password_reset_confirm.html' title = _('Enter new password') token_generator = default_token_generator @method_decorator(sensitive_post_parameters()) @method_decorator(never_cache) def dispatch(self, *args, **kwargs): assert 'uidb64' in kwargs and 'token' in kwargs self.validlink = False self.user = self.get_user(kwargs['uidb64']) if self.user is not None: token = kwargs['token'] if token == self.reset_url_token: session_token = self.request.session.get(INTERNAL_RESET_SESSION_TOKEN) if self.token_generator.check_token(self.user, session_token): # If the token is valid, display the password reset form. self.validlink = True return super().dispatch(*args, **kwargs) else: if self.token_generator.check_token(self.user, token): # Store the token in the session and redirect to the # password reset form at a URL without the token. That # avoids the possibility of leaking the token in the # HTTP Referer header. self.request.session[INTERNAL_RESET_SESSION_TOKEN] = token redirect_url = self.request.path.replace(token, self.reset_url_token) return HttpResponseRedirect(redirect_url) # Display the "Password reset unsuccessful" page. return self.render_to_response(self.get_context_data()) def get_user(self, uidb64): try: # urlsafe_base64_decode() decodes to bytestring uid = urlsafe_base64_decode(uidb64).decode() user = UserModel._default_manager.get(pk=uid) except (TypeError, ValueError, OverflowError, UserModel.DoesNotExist, ValidationError): user = None return user def get_form_kwargs(self): kwargs = super().get_form_kwargs() kwargs['user'] = self.user return kwargs def form_valid(self, form): user = form.save() del self.request.session[INTERNAL_RESET_SESSION_TOKEN] if self.post_reset_login: auth_login(self.request, user, self.post_reset_login_backend) return super().form_valid(form) def get_context_data(self, **kwargs): context = super().get_context_data(**kwargs) if self.validlink: context['validlink'] = True else: context.update({ 'form': None, 'title': _('Password reset unsuccessful'), 'validlink': False, }) return context class PasswordResetCompleteView(PasswordContextMixin, TemplateView): template_name = 'registration/password_reset_complete.html' title = _('Password reset complete') def get_context_data(self, **kwargs): context = super().get_context_data(**kwargs) context['login_url'] = resolve_url(settings.LOGIN_URL) return context class PasswordChangeView(PasswordContextMixin, FormView): form_class = PasswordChangeForm success_url = reverse_lazy('password_change_done') template_name = 'registration/password_change_form.html' title = _('Password change') @method_decorator(sensitive_post_parameters()) @method_decorator(csrf_protect) @method_decorator(login_required) def dispatch(self, *args, **kwargs): return super().dispatch(*args, **kwargs) def get_form_kwargs(self): kwargs = super().get_form_kwargs() kwargs['user'] = self.request.user return kwargs def form_valid(self, form): form.save() # Updating the password logs out all other sessions for the user # except the current one. update_session_auth_hash(self.request, form.user) return super().form_valid(form) class PasswordChangeDoneView(PasswordContextMixin, TemplateView): template_name = 'registration/password_change_done.html' title = _('Password change successful') @method_decorator(login_required) def dispatch(self, *args, **kwargs): return super().dispatch(*args, **kwargs)