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authentik/passbook/providers/saml/views.py
2020-07-08 14:27:58 +02:00

266 lines
11 KiB
Python

"""passbook SAML IDP Views"""
from typing import Optional
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, reverse
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 signxml.util import strip_pem_header
from structlog import get_logger
from passbook.audit.models import Event, EventAction
from passbook.core.models import Application, Provider
from passbook.flows.models import in_memory_stage
from passbook.flows.planner import (
PLAN_CONTEXT_APPLICATION,
PLAN_CONTEXT_SSO,
FlowPlanner,
)
from passbook.flows.stage import StageView
from passbook.flows.views import SESSION_KEY_PLAN
from passbook.lib.utils.template import render_to_string
from passbook.lib.utils.urls import redirect_with_qs
from passbook.lib.views import bad_request_message
from passbook.policies.mixins import PolicyAccessMixin
from passbook.providers.saml.exceptions import CannotHandleAssertion
from passbook.providers.saml.models import SAMLBindings, SAMLProvider
from passbook.providers.saml.processors.types import SAMLResponseParams
from passbook.stages.consent.stage import PLAN_CONTEXT_CONSENT_TEMPLATE
LOGGER = get_logger()
URL_VALIDATOR = URLValidator(schemes=("http", "https"))
SESSION_KEY_SAML_REQUEST = "SAMLRequest"
SESSION_KEY_SAML_RESPONSE = "SAMLResponse"
SESSION_KEY_RELAY_STATE = "RelayState"
SESSION_KEY_PARAMS = "SAMLParams"
class SAMLSSOView(LoginRequiredMixin, PolicyAccessMixin, View):
""""SAML SSO Base View, which plans a flow and injects our final stage.
Calls get/post handler."""
application: Application
provider: SAMLProvider
def dispatch(
self, request: HttpRequest, *args, application_slug: str, **kwargs
) -> HttpResponse:
self.application = get_object_or_404(Application, slug=application_slug)
self.provider: SAMLProvider = get_object_or_404(
SAMLProvider, pk=self.application.provider_id
)
if not request.user.is_authenticated:
return self.handle_no_permission()
if not self.user_has_access(self.application).passing:
return self.handle_no_permission_authorized()
# Call the method handler, which checks the SAML Request
method_response = super().dispatch(request, *args, application_slug, **kwargs)
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(
self.request,
{
PLAN_CONTEXT_SSO: True,
PLAN_CONTEXT_APPLICATION: self.application,
PLAN_CONTEXT_CONSENT_TEMPLATE: "providers/saml/consent.html",
},
)
plan.append(in_memory_stage(SAMLFlowFinalView))
self.request.session[SESSION_KEY_PLAN] = plan
return redirect_with_qs(
"passbook_flows:flow-executor-shell",
self.request.GET,
flow_slug=self.provider.authorization_flow.slug,
)
class SAMLSSOBindingRedirectView(SAMLSSOView):
"""SAML Handler for SSO/Redirect bindings, which are sent via GET"""
# pylint: disable=unused-argument
def get( # lgtm [py/similar-function]
self, request: HttpRequest, application_slug: str
) -> Optional[HttpResponse]:
"""Handle REDIRECT bindings"""
# Store these values now, because Django's login cycle won't preserve them.
if SESSION_KEY_SAML_REQUEST not in request.GET:
LOGGER.info("handle_saml_request: SAML payload missing")
return bad_request_message(
self.request, "The SAML request payload is missing."
)
self.request.session[SESSION_KEY_SAML_REQUEST] = request.GET[
SESSION_KEY_SAML_REQUEST
]
self.request.session[SESSION_KEY_RELAY_STATE] = request.GET.get(
SESSION_KEY_RELAY_STATE, ""
)
try:
self.provider.processor.can_handle(self.request)
params = self.provider.processor.generate_response()
self.request.session[SESSION_KEY_PARAMS] = params
except CannotHandleAssertion as exc:
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"""
# pylint: disable=unused-argument
def post(
self, request: HttpRequest, application_slug: str
) -> Optional[HttpResponse]:
"""Handle POST bindings"""
# Store these values now, because Django's login cycle won't preserve them.
if SESSION_KEY_SAML_REQUEST not in request.POST:
LOGGER.info("handle_saml_request: SAML payload missing")
return bad_request_message(
self.request, "The SAML request payload is missing."
)
self.request.session[SESSION_KEY_SAML_REQUEST] = request.POST[
SESSION_KEY_SAML_REQUEST
]
self.request.session[SESSION_KEY_RELAY_STATE] = request.POST.get(
SESSION_KEY_RELAY_STATE, ""
)
try:
self.provider.processor.can_handle(self.request)
params = self.provider.processor.generate_response()
self.request.session[SESSION_KEY_PARAMS] = params
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"""
# pylint: disable=unused-argument
def get(
self, request: HttpRequest, application_slug: str
) -> Optional[HttpResponse]:
"""Create saml params from scratch"""
LOGGER.debug(
"handle_saml_no_request: No SAML Request, using IdP-initiated flow."
)
self.provider.processor.is_idp_initiated = True
self.provider.processor.init_deep_link(self.request)
params = self.provider.processor.generate_response()
self.request.session[SESSION_KEY_PARAMS] = params
# 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)
self.request.session.pop(SESSION_KEY_SAML_REQUEST, None)
self.request.session.pop(SESSION_KEY_SAML_RESPONSE, None)
self.request.session.pop(SESSION_KEY_RELAY_STATE, None)
if SESSION_KEY_PARAMS not in self.request.session:
return self.executor.stage_invalid()
response: SAMLResponseParams = self.request.session.pop(SESSION_KEY_PARAMS)
if provider.sp_binding == SAMLBindings.POST:
return render(
self.request,
"generic/autosubmit_form.html",
{
"url": response.acs_url,
"title": _("Redirecting to %(app)s..." % {"app": application.name}),
"attrs": {
"ACSUrl": response.acs_url,
SESSION_KEY_SAML_RESPONSE: response.saml_response,
SESSION_KEY_RELAY_STATE: response.relay_state,
},
},
)
if provider.sp_binding == SAMLBindings.REDIRECT:
querystring = urlencode(
{
SESSION_KEY_SAML_RESPONSE: response.saml_response,
SESSION_KEY_RELAY_STATE: response.relay_state,
}
)
return redirect(f"{response.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"""
entity_id = provider.issuer
saml_sso_binding_post = request.build_absolute_uri(
reverse(
"passbook_providers_saml:sso-post",
kwargs={"application_slug": provider.application.slug},
)
)
saml_sso_binding_redirect = request.build_absolute_uri(
reverse(
"passbook_providers_saml:sso-redirect",
kwargs={"application_slug": provider.application.slug},
)
)
subject_format = provider.processor.subject_format
ctx = {
"saml_sso_binding_post": saml_sso_binding_post,
"saml_sso_binding_redirect": saml_sso_binding_redirect,
"entity_id": entity_id,
"subject_format": subject_format,
}
if provider.signing_kp:
ctx["cert_public_key"] = strip_pem_header(
provider.signing_kp.certificate_data.replace("\r", "")
).replace("\n", "")
return render_to_string("providers/saml/xml/metadata.xml", ctx)
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}_passbook_meta.xml"'
return response