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authentic2-auth-fc/src/authentic2_auth_fc/models.py

111 lines
3.6 KiB
Python

# authentic2-auth-fc - authentic2 authentication for FranceConnect
# Copyright (C) 2019 Entr'ouvert
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import base64
import json
import hmac
import hashlib
import urlparse
from django.db import models
from django.utils.translation import ugettext_lazy as _
from django.utils.timezone import now
from django.conf import settings
from authentic2_auth_oidc.utils import parse_timestamp
from . import app_settings
def base64url_decode(input):
rem = len(input) % 4
if rem > 0:
input += b'=' * (4 - rem)
return base64.urlsafe_b64decode(input)
def parse_id_token(id_token, client_id=None, client_secret=None):
try:
splitted = str(id_token).split('.')
except Exception:
return None, 'invalid id_token'
if len(splitted) != 3:
return None, 'invalid id_token'
header, payload, signature = splitted
try:
signature = base64url_decode(signature)
except (ValueError, TypeError):
return None, 'invalid signature'
signed = '%s.%s' % (header, payload)
if client_secret is not None:
h = hmac.HMAC(key=client_secret, msg=signed, digestmod=hashlib.sha256)
if h.digest() != signature:
return None, 'hmac signature does not match'
payload = base64url_decode(str(payload))
try:
payload = json.loads(payload)
except ValueError:
return None, 'invalid payload'
if client_id and ('aud' not in payload or payload['aud'] != client_id):
return None, 'invalid audience'
if 'exp' not in payload or parse_timestamp(payload['exp']) < now():
return None, 'id_token is expired'
def check_issuer():
parsed = urlparse.urlparse(app_settings.authorize_url)
if 'iss' not in payload:
return False
try:
parsed_issuer = urlparse.urlparse(payload['iss'])
except Exception:
return False
return parsed_issuer.scheme == parsed.scheme and parsed_issuer.netloc == parsed.netloc
if not check_issuer():
return None, 'wrong issuer received, %r' % payload['iss']
return payload, None
class FcAccount(models.Model):
user = models.ForeignKey(
to=settings.AUTH_USER_MODEL,
verbose_name=_('user'),
related_name='fc_accounts')
sub = models.TextField(
verbose_name=_('sub'),
db_index=True)
token = models.TextField(verbose_name=_('access token'))
user_info = models.TextField(verbose_name=_('access token'), blank=True, null=True)
@property
def id_token(self):
return parse_id_token(self.get_token()['id_token'])
def get_token(self):
return json.loads(self.token)
def get_user_info(self):
return json.loads(self.user_info)
def __unicode__(self):
user_info = self.get_user_info()
display_name = []
if 'given_name' in user_info:
display_name.append(user_info['given_name'])
if 'family_name' in user_info:
display_name.append(user_info['family_name'])
return ' '.join(display_name)