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authentik/authentik/providers/saml/views.py
Jens L a6d0c8c26c
providers/saml: Metadata Import ()
* providers/saml: add basic metadata parser

* providers/saml: add importer for Singing certificate, validate signature, add tests

* providers/saml: add provider name to form,

* web: don't use trailing slash for spa URLs

* providers/saml: formatting fixes

* sources/*: add verbose_name to source serializers

* admin: add button launch import modal
2020-12-27 22:38:04 +01:00

278 lines
11 KiB
Python

"""authentik SAML IDP Views"""
from typing import Optional
from django.contrib import messages
from django.contrib.auth.mixins import LoginRequiredMixin
from django.core.validators import URLValidator
from django.http import HttpRequest, HttpResponse
from django.shortcuts import get_object_or_404, redirect, render
from django.urls.base import reverse_lazy
from django.utils.decorators import method_decorator
from django.utils.http import urlencode
from django.utils.translation import gettext_lazy as _
from django.views import View
from django.views.decorators.csrf import csrf_exempt
from django.views.generic.edit import FormView
from structlog import get_logger
from authentik.core.models import Application, Provider
from authentik.events.models import Event, EventAction
from authentik.flows.models import in_memory_stage
from authentik.flows.planner import (
PLAN_CONTEXT_APPLICATION,
PLAN_CONTEXT_SSO,
FlowPlanner,
)
from authentik.flows.stage import StageView
from authentik.flows.views import SESSION_KEY_PLAN
from authentik.lib.utils.urls import redirect_with_qs
from authentik.lib.views import bad_request_message
from authentik.policies.views import PolicyAccessView
from authentik.providers.saml.exceptions import CannotHandleAssertion
from authentik.providers.saml.forms import SAMLProviderImportForm
from authentik.providers.saml.models import SAMLBindings, SAMLProvider
from authentik.providers.saml.processors.assertion import AssertionProcessor
from authentik.providers.saml.processors.metadata import MetadataProcessor
from authentik.providers.saml.processors.metadata_parser import (
ServiceProviderMetadataParser,
)
from authentik.providers.saml.processors.request_parser import (
AuthNRequest,
AuthNRequestParser,
)
from authentik.providers.saml.utils.encoding import deflate_and_base64_encode, nice64
from authentik.stages.consent.stage import PLAN_CONTEXT_CONSENT_TEMPLATE
LOGGER = get_logger()
URL_VALIDATOR = URLValidator(schemes=("http", "https"))
REQUEST_KEY_SAML_REQUEST = "SAMLRequest"
REQUEST_KEY_SAML_SIGNATURE = "Signature"
REQUEST_KEY_SAML_SIG_ALG = "SigAlg"
REQUEST_KEY_SAML_RESPONSE = "SAMLResponse"
REQUEST_KEY_RELAY_STATE = "RelayState"
SESSION_KEY_AUTH_N_REQUEST = "authn_request"
class SAMLSSOView(PolicyAccessView):
""" "SAML SSO Base View, which plans a flow and injects our final stage.
Calls get/post handler."""
def resolve_provider_application(self):
self.application = get_object_or_404(
Application, slug=self.kwargs["application_slug"]
)
self.provider: SAMLProvider = get_object_or_404(
SAMLProvider, pk=self.application.provider_id
)
def check_saml_request(self) -> Optional[HttpRequest]:
"""Handler to verify the SAML Request. Must be implemented by a subclass"""
raise NotImplementedError
# pylint: disable=unused-argument
def get(self, request: HttpRequest, application_slug: str) -> HttpResponse:
"""Verify the SAML Request, and if valid initiate the FlowPlanner for the application"""
# Call the method handler, which checks the SAML
# Request and returns a HTTP Response on error
method_response = self.check_saml_request()
if method_response:
return method_response
# Regardless, we start the planner and return to it
planner = FlowPlanner(self.provider.authorization_flow)
planner.allow_empty_flows = True
plan = planner.plan(
request,
{
PLAN_CONTEXT_SSO: True,
PLAN_CONTEXT_APPLICATION: self.application,
PLAN_CONTEXT_CONSENT_TEMPLATE: "providers/saml/consent.html",
},
)
plan.append(in_memory_stage(SAMLFlowFinalView))
request.session[SESSION_KEY_PLAN] = plan
return redirect_with_qs(
"authentik_flows:flow-executor-shell",
request.GET,
flow_slug=self.provider.authorization_flow.slug,
)
def post(self, request: HttpRequest, application_slug: str) -> HttpResponse:
"""GET and POST use the same handler, but we can't
override .dispatch easily because PolicyAccessView's dispatch"""
return self.get(request, application_slug)
class SAMLSSOBindingRedirectView(SAMLSSOView):
"""SAML Handler for SSO/Redirect bindings, which are sent via GET"""
def check_saml_request(self) -> Optional[HttpRequest]:
"""Handle REDIRECT bindings"""
if REQUEST_KEY_SAML_REQUEST not in self.request.GET:
LOGGER.info("handle_saml_request: SAML payload missing")
return bad_request_message(
self.request, "The SAML request payload is missing."
)
try:
auth_n_request = AuthNRequestParser(self.provider).parse_detached(
self.request.GET[REQUEST_KEY_SAML_REQUEST],
self.request.GET.get(REQUEST_KEY_RELAY_STATE),
self.request.GET.get(REQUEST_KEY_SAML_SIGNATURE),
self.request.GET.get(REQUEST_KEY_SAML_SIG_ALG),
)
self.request.session[SESSION_KEY_AUTH_N_REQUEST] = auth_n_request
except CannotHandleAssertion as exc:
Event.new(
EventAction.CONFIGURATION_ERROR,
provider=self.provider,
message=str(exc),
).save()
LOGGER.info(exc)
return bad_request_message(self.request, str(exc))
return None
@method_decorator(csrf_exempt, name="dispatch")
class SAMLSSOBindingPOSTView(SAMLSSOView):
"""SAML Handler for SSO/POST bindings"""
def check_saml_request(self) -> Optional[HttpRequest]:
"""Handle POST bindings"""
if REQUEST_KEY_SAML_REQUEST not in self.request.POST:
LOGGER.info("check_saml_request: SAML payload missing")
return bad_request_message(
self.request, "The SAML request payload is missing."
)
try:
auth_n_request = AuthNRequestParser(self.provider).parse(
self.request.POST[REQUEST_KEY_SAML_REQUEST],
self.request.POST.get(REQUEST_KEY_RELAY_STATE),
)
self.request.session[SESSION_KEY_AUTH_N_REQUEST] = auth_n_request
except CannotHandleAssertion as exc:
LOGGER.info(exc)
return bad_request_message(self.request, str(exc))
return None
class SAMLSSOBindingInitView(SAMLSSOView):
"""SAML Handler for for IdP Initiated login flows"""
def check_saml_request(self) -> Optional[HttpRequest]:
"""Create SAML Response from scratch"""
LOGGER.debug(
"handle_saml_no_request: No SAML Request, using IdP-initiated flow."
)
auth_n_request = AuthNRequestParser(self.provider).idp_initiated()
self.request.session[SESSION_KEY_AUTH_N_REQUEST] = auth_n_request
# This View doesn't have a URL on purpose, as its called by the FlowExecutor
class SAMLFlowFinalView(StageView):
"""View used by FlowExecutor after all stages have passed. Logs the authorization,
and redirects to the SP (if REDIRECT is configured) or shows and auto-submit for
(if POST is configured)."""
def get(self, request: HttpRequest, *args, **kwargs) -> HttpResponse:
application: Application = self.executor.plan.context[PLAN_CONTEXT_APPLICATION]
provider: SAMLProvider = get_object_or_404(
SAMLProvider, pk=application.provider_id
)
# Log Application Authorization
Event.new(
EventAction.AUTHORIZE_APPLICATION,
authorized_application=application,
flow=self.executor.plan.flow_pk,
).from_http(self.request)
if SESSION_KEY_AUTH_N_REQUEST not in self.request.session:
return self.executor.stage_invalid()
auth_n_request: AuthNRequest = self.request.session.pop(
SESSION_KEY_AUTH_N_REQUEST
)
response = AssertionProcessor(
provider, request, auth_n_request
).build_response()
if provider.sp_binding == SAMLBindings.POST:
form_attrs = {
"ACSUrl": provider.acs_url,
REQUEST_KEY_SAML_RESPONSE: nice64(response),
}
if auth_n_request.relay_state:
form_attrs[REQUEST_KEY_RELAY_STATE] = auth_n_request.relay_state
return render(
self.request,
"generic/autosubmit_form.html",
{
"url": provider.acs_url,
"title": _("Redirecting to %(app)s..." % {"app": application.name}),
"attrs": form_attrs,
},
)
if provider.sp_binding == SAMLBindings.REDIRECT:
url_args = {
REQUEST_KEY_SAML_RESPONSE: deflate_and_base64_encode(response),
}
if auth_n_request.relay_state:
url_args[REQUEST_KEY_RELAY_STATE] = auth_n_request.relay_state
querystring = urlencode(url_args)
return redirect(f"{provider.acs_url}?{querystring}")
return bad_request_message(request, "Invalid sp_binding specified")
class DescriptorDownloadView(View):
"""Replies with the XML Metadata IDSSODescriptor."""
@staticmethod
def get_metadata(request: HttpRequest, provider: SAMLProvider) -> str:
"""Return rendered XML Metadata"""
return MetadataProcessor(provider, request).build_entity_descriptor()
def get(self, request: HttpRequest, application_slug: str) -> HttpResponse:
"""Replies with the XML Metadata IDSSODescriptor."""
application = get_object_or_404(Application, slug=application_slug)
provider: SAMLProvider = get_object_or_404(
SAMLProvider, pk=application.provider_id
)
try:
metadata = DescriptorDownloadView.get_metadata(request, provider)
except Provider.application.RelatedObjectDoesNotExist: # pylint: disable=no-member
return bad_request_message(
request, "Provider is not assigned to an application."
)
else:
response = HttpResponse(metadata, content_type="application/xml")
response[
"Content-Disposition"
] = f'attachment; filename="{provider.name}_authentik_meta.xml"'
return response
class MetadataImportView(LoginRequiredMixin, FormView):
"""Import Metadata from XML, and create provider"""
form_class = SAMLProviderImportForm
template_name = "providers/saml/import.html"
success_url = reverse_lazy("authentik_admin:providers")
def dispatch(self, request, *args, **kwargs):
if not request.user.is_superuser:
return self.handle_no_permission()
return super().dispatch(request, *args, **kwargs)
def form_valid(self, form: SAMLProviderImportForm) -> HttpResponse:
try:
metadata = ServiceProviderMetadataParser().parse(
form.cleaned_data["metadata"].read().decode()
)
provider = metadata.to_provider(form.cleaned_data["provider_name"])
provider.save()
messages.success(self.request, _("Successfully created Provider"))
except ValueError:
messages.error(self.request, _("Failed to import Metadata."))
return super().form_valid(form)