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 is_safe_url, 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 = is_safe_url(
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 = is_safe_url(
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_URL_TOKEN = 'set-password'
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
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 == INTERNAL_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, INTERNAL_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)