# Copyright (C) 2010-2013 Yaco Sistemas (http://www.yaco.es) # Copyright (C) 2009 Lorenzo Gil Sanchez # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import logging try: from xml.etree import ElementTree except ImportError: from elementtree import ElementTree from django.conf import settings from django.contrib import auth from django.contrib.auth.decorators import login_required from django.contrib.auth.views import logout as django_logout from django.http import Http404, HttpResponse from django.http import HttpResponseRedirect # 30x from django.http import HttpResponseBadRequest, HttpResponseForbidden # 40x from django.http import HttpResponseServerError # 50x from django.views.decorators.http import require_POST from django.shortcuts import render_to_response from django.template import RequestContext try: from django.views.decorators.csrf import csrf_exempt except ImportError: # Django 1.0 compatibility def csrf_exempt(view_func): return view_func from saml2 import BINDING_HTTP_REDIRECT, BINDING_HTTP_POST from saml2.client import Saml2Client from saml2.metadata import entity_descriptor from saml2.ident import code, decode from djangosaml2.cache import IdentityCache, OutstandingQueriesCache from djangosaml2.cache import StateCache from djangosaml2.conf import get_config from djangosaml2.signals import post_authenticated from djangosaml2.utils import get_custom_setting, available_idps, get_location logger = logging.getLogger('djangosaml2') def _set_subject_id(session, subject_id): session['_saml2_subject_id'] = code(subject_id) def _get_subject_id(session): try: return decode(session['_saml2_subject_id']) except KeyError: return None def login(request, config_loader_path=None, wayf_template='djangosaml2/wayf.html', authorization_error_template='djangosaml2/auth_error.html'): """SAML Authorization Request initiator This view initiates the SAML2 Authorization handshake using the pysaml2 library to create the AuthnRequest. It uses the SAML 2.0 Http Redirect protocol binding. """ logger.debug('Login process started') came_from = request.GET.get('next', settings.LOGIN_REDIRECT_URL) if not came_from: logger.warning('The next parameter exists but is empty') came_from = settings.LOGIN_REDIRECT_URL # if the user is already authenticated that maybe because of two reasons: # A) He has this URL in two browser windows and in the other one he # has already initiated the authenticated session. # B) He comes from a view that (incorrectly) send him here because # he does not have enough permissions. That view should have shown # an authorization error in the first place. # We can only make one thing here and that is configurable with the # SAML_IGNORE_AUTHENTICATED_USERS_ON_LOGIN setting. If that setting # is True (default value) we will redirect him to the came_from view. # Otherwise, we will show an (configurable) authorization error. if not request.user.is_anonymous(): try: redirect_authenticated_user = settings.SAML_IGNORE_AUTHENTICATED_USERS_ON_LOGIN except AttributeError: redirect_authenticated_user = True if redirect_authenticated_user: return HttpResponseRedirect(came_from) else: logger.debug('User is already logged in') return render_to_response(authorization_error_template, { 'came_from': came_from, }, context_instance=RequestContext(request)) selected_idp = request.GET.get('idp', None) conf = get_config(config_loader_path, request) # is a embedded wayf needed? idps = available_idps(conf) if selected_idp is None and len(idps) > 1: logger.debug('A discovery process is needed') return render_to_response(wayf_template, { 'available_idps': idps.items(), 'came_from': came_from, }, context_instance=RequestContext(request)) client = Saml2Client(conf) try: (session_id, result) = client.prepare_for_authenticate( entityid=selected_idp, relay_state=came_from, binding=BINDING_HTTP_REDIRECT, ) except TypeError, e: logger.error('Unable to know which IdP to use') return HttpResponse(unicode(e)) logger.debug('Saving the session_id in the OutstandingQueries cache') oq_cache = OutstandingQueriesCache(request.session) oq_cache.set(session_id, came_from) logger.debug('Redirecting the user to the IdP') return HttpResponseRedirect(get_location(result)) @require_POST @csrf_exempt def assertion_consumer_service(request, config_loader_path=None, attribute_mapping=None, create_unknown_user=None): """SAML Authorization Response endpoint The IdP will send its response to this view, which will process it with pysaml2 help and log the user in using the custom Authorization backend djangosaml2.backends.Saml2Backend that should be enabled in the settings.py """ attribute_mapping = attribute_mapping or get_custom_setting( 'SAML_ATTRIBUTE_MAPPING', {'uid': ('username', )}) create_unknown_user = create_unknown_user or get_custom_setting( 'SAML_CREATE_UNKNOWN_USER', True) logger.debug('Assertion Consumer Service started') conf = get_config(config_loader_path, request) if 'SAMLResponse' not in request.POST: return HttpResponseBadRequest( 'Couldn\'t find "SAMLResponse" in POST data.') xmlstr = request.POST['SAMLResponse'] client = Saml2Client(conf, identity_cache=IdentityCache(request.session)) oq_cache = OutstandingQueriesCache(request.session) outstanding_queries = oq_cache.outstanding_queries() # process the authentication response response = client.parse_authn_request_response(xmlstr, BINDING_HTTP_POST, outstanding_queries) if response is None: logger.error('SAML response is None') return HttpResponseBadRequest( "SAML response has errors. Please check the logs") session_id = response.session_id() oq_cache.delete(session_id) # authenticate the remote user session_info = response.session_info() if callable(attribute_mapping): attribute_mapping = attribute_mapping() if callable(create_unknown_user): create_unknown_user = create_unknown_user() logger.debug('Trying to authenticate the user') user = auth.authenticate(session_info=session_info, attribute_mapping=attribute_mapping, create_unknown_user=create_unknown_user) if user is None: logger.error('The user is None') return HttpResponseForbidden("Permission denied") auth.login(request, user) _set_subject_id(request.session, session_info['name_id']) logger.debug('Sending the post_authenticated signal') post_authenticated.send_robust(sender=user, session_info=session_info) # redirect the user to the view where he came from relay_state = request.POST.get('RelayState', '/') if not relay_state: logger.warning('The RelayState parameter exists but is empty') relay_state = settings.LOGIN_REDIRECT_URL logger.debug('Redirecting to the RelayState: ' + relay_state) return HttpResponseRedirect(relay_state) @login_required def echo_attributes(request, config_loader_path=None, template='djangosaml2/echo_attributes.html'): """Example view that echo the SAML attributes of an user""" state = StateCache(request.session) conf = get_config(config_loader_path, request) client = Saml2Client(conf, state_cache=state, identity_cache=IdentityCache(request.session)) subject_id = _get_subject_id(request.session) identity = client.users.get_identity(subject_id, check_not_on_or_after=False) return render_to_response(template, {'attributes': identity[0]}, context_instance=RequestContext(request)) @login_required def logout(request, config_loader_path=None): """SAML Logout Request initiator This view initiates the SAML2 Logout request using the pysaml2 library to create the LogoutRequest. """ logger.debug('Logout process started') state = StateCache(request.session) conf = get_config(config_loader_path, request) client = Saml2Client(conf, state_cache=state, identity_cache=IdentityCache(request.session)) subject_id = _get_subject_id(request.session) if subject_id is None: logger.warning( 'The session does not contains the subject id for user %s' % request.user) result = client.global_logout(subject_id) state.sync() if not result: logger.error("Looks like the user %s is not logged in any IdP/AA" % subject_id) return HttpResponseBadRequest("You are not logged in any IdP/AA") if len(result) > 1: logger.error('Sorry, I do not know how to logout from several sources. I will logout just from the first one') for entityid, logout_info in result.items(): if isinstance(logout_info, tuple): binding, http_info = logout_info if binding == BINDING_HTTP_POST: logger.debug('Returning form to the IdP to continue the logout process') body = ''.join(http_info['data']) return HttpResponse(body) elif binding == BINDING_HTTP_REDIRECT: logger.debug('Redirecting to the IdP to continue the logout process') return HttpResponseRedirect(get_location(http_info)) else: logger.error('Unknown binding: %s', binding) return HttpResponseServerError('Failed to log out') else: # We must have had a soap logout return finish_logout(request, logout_info) logger.error('Could not logout because there only the HTTP_REDIRECT is supported') return HttpResponseServerError('Logout Binding not supported') def logout_service(request, *args, **kwargs): return do_logout_service(request, request.GET, BINDING_HTTP_REDIRECT, *args, **kwargs) @csrf_exempt def logout_service_post(request, *args, **kwargs): return do_logout_service(request, request.POST, BINDING_HTTP_POST, *args, **kwargs) def do_logout_service(request, data, binding, config_loader_path=None, next_page=None, logout_error_template='djangosaml2/logout_error.html'): """SAML Logout Response endpoint The IdP will send the logout response to this view, which will process it with pysaml2 help and log the user out. Note that the IdP can request a logout even when we didn't initiate the process as a single logout request started by another SP. """ logger.debug('Logout service started') conf = get_config(config_loader_path, request) state = StateCache(request.session) client = Saml2Client(conf, state_cache=state, identity_cache=IdentityCache(request.session)) if 'SAMLResponse' in data: # we started the logout logger.debug('Receiving a logout response from the IdP') response = client.parse_logout_request_response(data['SAMLResponse'], binding) state.sync() return finish_logout(request, response, next_page=next_page) elif 'SAMLRequest' in data: # logout started by the IdP logger.debug('Receiving a logout request from the IdP') subject_id = _get_subject_id(request.session) if subject_id is None: logger.warning( 'The session does not contain the subject id for user %s. Performing local logout' % request.user) auth.logout(request) return render_to_response(logout_error_template, {}, context_instance=RequestContext(request)) else: http_info = client.handle_logout_request( data['SAMLRequest'], subject_id, binding) state.sync() auth.logout(request) return HttpResponseRedirect(get_location(http_info)) else: logger.error('No SAMLResponse or SAMLRequest parameter found') raise Http404('No SAMLResponse or SAMLRequest parameter found') def finish_logout(request, response, next_page=None): if response and response.status_ok(): if next_page is None and hasattr(settings, 'LOGOUT_REDIRECT_URL'): next_page = settings.LOGOUT_REDIRECT_URL logger.debug('Performing django_logout with a next_page of %s' % next_page) return django_logout(request, next_page=next_page) else: logger.error('Unknown error during the logout') return HttpResponse('Error during logout') def metadata(request, config_loader_path=None, valid_for=None): """Returns an XML with the SAML 2.0 metadata for this SP as configured in the settings.py file. """ conf = get_config(config_loader_path, request) metadata = entity_descriptor(conf) return HttpResponse(content=str(metadata), content_type="text/xml; charset=utf8") def register_namespace_prefixes(): from saml2 import md, saml, samlp import xmlenc import xmldsig prefixes = (('saml', saml.NAMESPACE), ('samlp', samlp.NAMESPACE), ('md', md.NAMESPACE), ('ds', xmldsig.NAMESPACE), ('xenc', xmlenc.NAMESPACE)) if hasattr(ElementTree, 'register_namespace'): for prefix, namespace in prefixes: ElementTree.register_namespace(prefix, namespace) else: for prefix, namespace in prefixes: ElementTree._namespace_map[namespace] = prefix register_namespace_prefixes()