import os
from base64 import b32encode, b32decode
from collections import OrderedDict
from six import BytesIO
from six.moves.urllib.parse import quote
from django.views.generic import FormView, ListView, TemplateView
from django.contrib.auth.forms import AuthenticationForm
from django.contrib.auth import load_backend
from django.contrib.auth.views import LoginView
from django.contrib.auth.decorators import login_required
from django.contrib import auth, messages
from django.conf import settings
from django.http import HttpResponseRedirect
from django.urls import reverse, reverse_lazy
from django.utils.http import is_safe_url, urlencode
from django.shortcuts import resolve_url, get_object_or_404
from django.contrib.sites.shortcuts import get_current_site
from django.utils.functional import cached_property
from django.utils.translation import ugettext as _
import qrcode
from qrcode.image.svg import SvgPathImage
from u2flib_server import u2f
from .forms import KeyResponseForm, BackupCodeForm, TOTPForm, KeyRegistrationForm
from .models import TOTPDevice
class U2FLoginView(LoginView):
form_class = AuthenticationForm
template_name = 'u2f/login.html'
@property
def is_admin(self):
return self.template_name == 'admin/login.html'
def requires_two_factor(self, user):
return (user.u2f_keys.exists() or
user.backup_codes.exists() or
user.totp_devices.exists())
def form_valid(self, form):
user = form.get_user()
if not self.requires_two_factor(user):
# no keys registered, use single-factor auth
return super(U2FLoginView, self).form_valid(form)
else:
self.request.session['u2f_pre_verify_user_pk'] = user.pk
self.request.session['u2f_pre_verify_user_backend'] = user.backend
verify_url = reverse('u2f:verify-second-factor')
redirect_to = self.request.POST.get(auth.REDIRECT_FIELD_NAME,
self.request.GET.get(auth.REDIRECT_FIELD_NAME, ''))
params = {}
if is_safe_url(url=redirect_to, allowed_hosts=self.request.get_host()):
params[auth.REDIRECT_FIELD_NAME] = redirect_to
if self.is_admin:
params['admin'] = 1
if params:
verify_url += '?' + urlencode(params)
return HttpResponseRedirect(verify_url)
def get_context_data(self, **kwargs):
kwargs = super(U2FLoginView, self).get_context_data(**kwargs)
kwargs[auth.REDIRECT_FIELD_NAME] = self.request.GET.get(auth.REDIRECT_FIELD_NAME, '')
kwargs.update(self.kwargs.get('extra_context', {}))
return kwargs
class AdminU2FLoginView(U2FLoginView):
template_name = 'admin/login.html'
class OriginMixin(object):
def get_origin(self):
return '{scheme}://{host}'.format(
scheme=self.request.scheme,
host=self.request.get_host(),
)
class AddKeyView(OriginMixin, FormView):
template_name = 'u2f/add_key.html'
form_class = KeyRegistrationForm
success_url = reverse_lazy('u2f:u2f-keys')
def dispatch(self, request, *args, **kwargs):
return super(AddKeyView, self).dispatch(request, *args, **kwargs)
def get_form_kwargs(self):
kwargs = super(AddKeyView, self).get_form_kwargs()
kwargs.update(
user=self.request.user,
request=self.request,
appId=self.get_origin(),
)
return kwargs
def get_context_data(self, **kwargs):
kwargs = super(AddKeyView, self).get_context_data(**kwargs)
request = u2f.begin_registration(self.get_origin(), [
key.to_json() for key in self.request.user.u2f_keys.all()
])
self.request.session['u2f_registration_request'] = request
kwargs['registration_request'] = request
return kwargs
def form_valid(self, form):
response = form.cleaned_data['response']
request = self.request.session['u2f_registration_request']
del self.request.session['u2f_registration_request']
device, attestation_cert = u2f.complete_registration(request, response)
self.request.user.u2f_keys.create(
public_key=device['publicKey'],
key_handle=device['keyHandle'],
app_id=device['appId'],
)
messages.success(self.request, _("Key added."))
return super(AddKeyView, self).form_valid(form)
def get_success_url(self):
if 'next' in self.request.GET and is_safe_url(self.request.GET['next']):
return self.request.GET['next']
else:
return super(AddKeyView, self).get_success_url()
class VerifySecondFactorView(OriginMixin, TemplateView):
template_name = 'u2f/verify_second_factor.html'
@property
def form_classes(self):
ret = {}
if self.user.u2f_keys.exists():
ret['u2f'] = KeyResponseForm
if self.user.backup_codes.exists():
ret['backup'] = BackupCodeForm
if self.user.totp_devices.exists():
ret['totp'] = TOTPForm
return ret
def get_user(self):
try:
user_id = self.request.session['u2f_pre_verify_user_pk']
backend_path = self.request.session['u2f_pre_verify_user_backend']
assert backend_path in settings.AUTHENTICATION_BACKENDS
backend = load_backend(backend_path)
user = backend.get_user(user_id)
if user is not None:
user.backend = backend_path
return user
except (KeyError, AssertionError):
return None
def dispatch(self, request, *args, **kwargs):
self.user = self.get_user()
if self.user is None:
return HttpResponseRedirect(reverse('u2f:login'))
return super(VerifySecondFactorView, self).dispatch(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
forms = self.get_forms()
form = forms[request.POST['type']]
if form.is_valid():
return self.form_valid(form, forms)
else:
return self.form_invalid(forms)
def form_invalid(self, forms):
return self.render_to_response(self.get_context_data(
forms=forms,
))
def get_form_kwargs(self):
return {
'user': self.user,
'request': self.request,
'appId': self.get_origin(),
}
def get_forms(self):
kwargs = self.get_form_kwargs()
if self.request.method == 'GET':
forms = {key: form(**kwargs) for key, form in self.form_classes.items()}
else:
method = self.request.POST['type']
forms = {
key: form(**kwargs)
for key, form in self.form_classes.items()
if key != method
}
forms[method] = self.form_classes[method](self.request.POST, **kwargs)
return forms
def get_context_data(self, **kwargs):
if 'forms' not in kwargs:
kwargs['forms'] = self.get_forms()
kwargs = super(VerifySecondFactorView, self).get_context_data(**kwargs)
if self.request.GET.get('admin'):
kwargs['base_template'] = 'admin/base_site.html'
else:
kwargs['base_template'] = 'base.html'
kwargs['user'] = self.user
return kwargs
def form_valid(self, form, forms):
if not form.validate_second_factor():
return self.form_invalid(forms)
del self.request.session['u2f_pre_verify_user_pk']
del self.request.session['u2f_pre_verify_user_backend']
auth.login(self.request, self.user)
redirect_to = self.request.POST.get(auth.REDIRECT_FIELD_NAME,
self.request.GET.get(auth.REDIRECT_FIELD_NAME, ''))
if not is_safe_url(url=redirect_to, allowed_hosts=self.request.get_host()):
redirect_to = resolve_url(settings.LOGIN_REDIRECT_URL)
return HttpResponseRedirect(redirect_to)
class TwoFactorSettingsView(TemplateView):
template_name = 'u2f/two_factor_settings.html'
def get_context_data(self, **kwargs):
context= super(TwoFactorSettingsView, self).get_context_data(**kwargs)
context['u2f_enabled'] = self.request.user.u2f_keys.exists()
context['backup_codes'] = self.request.user.backup_codes.all()
context['totp_enabled'] = self.request.user.totp_devices.exists()
return context
class KeyManagementView(ListView):
template_name = 'u2f/key_list.html'
def get_queryset(self):
return self.request.user.u2f_keys.all()
def post(self, request):
assert 'delete' in self.request.POST
key = get_object_or_404(self.get_queryset(), pk=self.request.POST['key_id'])
key.delete()
if self.get_queryset().exists():
messages.success(request, _("Key removed."))
else:
messages.success(request, _("Key removed. Two-factor auth disabled."))
return HttpResponseRedirect(reverse('u2f:u2f-keys'))
class BackupCodesView(ListView):
template_name = 'u2f/backup_codes.html'
def get_queryset(self):
return self.request.user.backup_codes.all()
def post(self, request):
for i in range(10):
self.request.user.backup_codes.create_backup_code()
return HttpResponseRedirect(self.request.build_absolute_uri())
class AddTOTPDeviceView(OriginMixin, FormView):
form_class = TOTPForm
template_name = 'u2f/totp_device.html'
success_url = reverse_lazy('u2f:two-factor-settings')
def gen_key(self):
return os.urandom(20)
def get_otpauth_url(self, key):
secret = b32encode(key)
issuer = get_current_site(self.request).name
params = OrderedDict([
('secret', secret),
('digits', 6),
('issuer', issuer),
])
return 'otpauth://totp/{issuer}:{username}?{params}'.format(
issuer=quote(issuer),
username=quote(self.request.user.get_username()),
params=urlencode(params),
)
def get_qrcode(self, data):
img = qrcode.make(data, image_factory=SvgPathImage)
buf = BytesIO()
img.save(buf)
return buf.getvalue()
@cached_property
def key(self):
try:
return b32decode(self.request.POST['base32_key'])
except KeyError:
return self.gen_key()
def get_context_data(self, **kwargs):
kwargs = super(AddTOTPDeviceView, self).get_context_data(**kwargs)
kwargs['base32_key'] = b32encode(self.key).decode()
kwargs['otpauth'] = self.get_otpauth_url(self.key)
kwargs['qr_svg'] = self.get_qrcode(kwargs['otpauth'])
return kwargs
def get_form_kwargs(self):
kwargs = super(AddTOTPDeviceView, self).get_form_kwargs()
kwargs.update(
user=self.request.user,
request=self.request,
appId=self.get_origin(),
)
return kwargs
def form_valid(self, form):
device = TOTPDevice(
user=self.request.user,
key=self.key,
)
if device.validate_token(form.cleaned_data['token']):
device.save()
messages.success(self.request, _("Device added."))
return super(AddTOTPDeviceView, self).form_valid(form)
else:
assert not device.pk
form.add_error('token', TOTPForm.INVALID_ERROR_MESSAGE)
return self.form_invalid(form)
def form_invalid(self, form):
# Should this go in Django's FormView?!
# <https://code.djangoproject.com/ticket/25548>
return self.render_to_response(self.get_context_data(form=form))
def get_success_url(self):
if 'next' in self.request.GET and is_safe_url(self.request.GET['next']):
return self.request.GET['next']
else:
return super(AddTOTPDeviceView, self).get_success_url()
class TOTPDeviceManagementView(ListView):
template_name = 'u2f/totpdevice_list.html'
def get_queryset(self):
return self.request.user.totp_devices.all()
def post(self, request):
assert 'delete' in self.request.POST
device = get_object_or_404(self.get_queryset(), pk=self.request.POST['device_id'])
device.delete()
messages.success(request, _("Device removed."))
return HttpResponseRedirect(reverse('u2f:totp-devices'))
add_key = login_required(AddKeyView.as_view())
verify_second_factor = VerifySecondFactorView.as_view()
login = U2FLoginView.as_view()
keys = login_required(KeyManagementView.as_view())
two_factor_settings = login_required(TwoFactorSettingsView.as_view())
backup_codes = login_required(BackupCodesView.as_view())
add_totp = login_required(AddTOTPDeviceView.as_view())
totp_devices = login_required(TOTPDeviceManagementView.as_view())
