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authentik/passbook/flows/views.py
Jens Langhammer b452e751ea flows: add SESSION_KEY_APPLICATION_PRE
whenever a user tries to access an application without being authenticated to passbook, we now show notice which application they are going to continue to.
2020-07-12 22:47:46 +02:00

280 lines
11 KiB
Python

"""passbook multi-stage authentication engine"""
from traceback import format_tb
from typing import Any, Dict, Optional
from django.http import (
Http404,
HttpRequest,
HttpResponse,
HttpResponseRedirect,
JsonResponse,
)
from django.shortcuts import get_object_or_404, redirect, render, reverse
from django.template.response import TemplateResponse
from django.utils.decorators import method_decorator
from django.views.decorators.clickjacking import xframe_options_sameorigin
from django.views.generic import TemplateView, View
from structlog import get_logger
from passbook.audit.models import cleanse_dict
from passbook.core.views.utils import PermissionDeniedView
from passbook.flows.exceptions import EmptyFlowException, FlowNonApplicableException
from passbook.flows.models import Flow, FlowDesignation, Stage
from passbook.flows.planner import FlowPlan, FlowPlanner
from passbook.lib.utils.reflection import class_to_path, path_to_class
from passbook.lib.utils.urls import redirect_with_qs
from passbook.lib.views import bad_request_message
LOGGER = get_logger()
# Argument used to redirect user after login
NEXT_ARG_NAME = "next"
SESSION_KEY_PLAN = "passbook_flows_plan"
SESSION_KEY_APPLICATION_PRE = "passbook_flows_application_pre"
SESSION_KEY_GET = "passbook_flows_get"
@method_decorator(xframe_options_sameorigin, name="dispatch")
class FlowExecutorView(View):
"""Stage 1 Flow executor, passing requests to Stage Views"""
flow: Flow
plan: Optional[FlowPlan] = None
current_stage: Stage
current_stage_view: View
def setup(self, request: HttpRequest, flow_slug: str):
super().setup(request, flow_slug=flow_slug)
self.flow = get_object_or_404(Flow.objects.select_related(), slug=flow_slug)
def handle_invalid_flow(self, exc: BaseException) -> HttpResponse:
"""When a flow is non-applicable check if user is on the correct domain"""
if NEXT_ARG_NAME in self.request.GET:
LOGGER.debug("f(exec): Redirecting to next on fail")
return redirect(self.request.GET.get(NEXT_ARG_NAME))
message = exc.__doc__ if exc.__doc__ else str(exc)
return bad_request_message(self.request, message)
def dispatch(self, request: HttpRequest, flow_slug: str) -> HttpResponse:
# Early check if theres an active Plan for the current session
if SESSION_KEY_PLAN in self.request.session:
self.plan = self.request.session[SESSION_KEY_PLAN]
if self.plan.flow_pk != self.flow.pk.hex:
LOGGER.warning(
"f(exec): Found existing plan for other flow, deleteing plan",
flow_slug=flow_slug,
)
# Existing plan is deleted from session and instance
self.plan = None
self.cancel()
LOGGER.debug("f(exec): Continuing existing plan", flow_slug=flow_slug)
# Don't check session again as we've either already loaded the plan or we need to plan
if not self.plan:
LOGGER.debug(
"f(exec): No active Plan found, initiating planner", flow_slug=flow_slug
)
try:
self.plan = self._initiate_plan()
except FlowNonApplicableException as exc:
LOGGER.warning("f(exec): Flow not applicable to current user", exc=exc)
return self.handle_invalid_flow(exc)
except EmptyFlowException as exc:
LOGGER.warning("f(exec): Flow is empty", exc=exc)
return self.handle_invalid_flow(exc)
# We don't save the Plan after getting the next stage
# as it hasn't been successfully passed yet
self.current_stage = self.plan.next()
LOGGER.debug(
"f(exec): Current stage",
current_stage=self.current_stage,
flow_slug=self.flow.slug,
)
if not self.current_stage:
LOGGER.debug("f(exec): no more stages, flow is done.")
return self._flow_done()
stage_cls = path_to_class(self.current_stage.type)
self.current_stage_view = stage_cls(self)
self.current_stage_view.args = self.args
self.current_stage_view.kwargs = self.kwargs
self.current_stage_view.request = request
return super().dispatch(request)
def get(self, request: HttpRequest, *args, **kwargs) -> HttpResponse:
"""pass get request to current stage"""
LOGGER.debug(
"f(exec): Passing GET",
view_class=class_to_path(self.current_stage_view.__class__),
stage=self.current_stage,
flow_slug=self.flow.slug,
)
try:
stage_response = self.current_stage_view.get(request, *args, **kwargs)
return to_stage_response(request, stage_response)
except Exception as exc: # pylint: disable=broad-except
LOGGER.exception(exc)
return to_stage_response(
request,
render(
request,
"flows/error.html",
{"error": exc, "tb": "".join(format_tb(exc.__traceback__))},
),
)
def post(self, request: HttpRequest, *args, **kwargs) -> HttpResponse:
"""pass post request to current stage"""
LOGGER.debug(
"f(exec): Passing POST",
view_class=class_to_path(self.current_stage_view.__class__),
stage=self.current_stage,
flow_slug=self.flow.slug,
)
try:
stage_response = self.current_stage_view.post(request, *args, **kwargs)
return to_stage_response(request, stage_response)
except Exception as exc: # pylint: disable=broad-except
LOGGER.exception(exc)
return to_stage_response(
request,
render(
request,
"flows/error.html",
{"error": exc, "tb": "".join(format_tb(exc.__traceback__))},
),
)
def _initiate_plan(self) -> FlowPlan:
planner = FlowPlanner(self.flow)
plan = planner.plan(self.request)
self.request.session[SESSION_KEY_PLAN] = plan
return plan
def _flow_done(self) -> HttpResponse:
"""User Successfully passed all stages"""
self.cancel()
# Since this is wrapped by the ExecutorShell, the next argument is saved in the session
next_param = self.request.session.get(SESSION_KEY_GET, {}).get(
NEXT_ARG_NAME, "passbook_core:overview"
)
return redirect_with_qs(next_param)
def stage_ok(self) -> HttpResponse:
"""Callback called by stages upon successful completion.
Persists updated plan and context to session."""
LOGGER.debug(
"f(exec): Stage ok",
stage_class=class_to_path(self.current_stage_view.__class__),
flow_slug=self.flow.slug,
)
# We call plan.next here to check for re-evaluate markers
# this is important so we can save the result
# and we don't have to re-evaluate the policies each request
self.plan.next()
self.plan.pop()
self.request.session[SESSION_KEY_PLAN] = self.plan
if self.plan.stages:
LOGGER.debug(
"f(exec): Continuing with next stage",
reamining=len(self.plan.stages),
flow_slug=self.flow.slug,
)
return redirect_with_qs(
"passbook_flows:flow-executor", self.request.GET, **self.kwargs
)
# User passed all stages
LOGGER.debug(
"f(exec): User passed all stages",
flow_slug=self.flow.slug,
context=cleanse_dict(self.plan.context),
)
return self._flow_done()
def stage_invalid(self) -> HttpResponse:
"""Callback used stage when data is correct but a policy denies access
or the user account is disabled."""
LOGGER.debug("f(exec): Stage invalid", flow_slug=self.flow.slug)
self.cancel()
return redirect_with_qs("passbook_flows:denied", self.request.GET)
def cancel(self):
"""Cancel current execution and return a redirect"""
keys_to_delete = [
SESSION_KEY_APPLICATION_PRE,
SESSION_KEY_PLAN,
SESSION_KEY_GET,
]
for key in keys_to_delete:
if key in self.request.session:
del self.request.session[key]
class FlowPermissionDeniedView(PermissionDeniedView):
"""User could not be authenticated"""
class FlowExecutorShellView(TemplateView):
"""Executor Shell view, loads a dummy card with a spinner
that loads the next stage in the background."""
template_name = "flows/shell.html"
def get_context_data(self, **kwargs) -> Dict[str, Any]:
kwargs["exec_url"] = reverse("passbook_flows:flow-executor", kwargs=self.kwargs)
kwargs["msg_url"] = reverse("passbook_api:messages-list")
self.request.session[SESSION_KEY_GET] = self.request.GET
return kwargs
class CancelView(View):
"""View which canels the currently active plan"""
def get(self, request: HttpRequest) -> HttpResponse:
"""View which canels the currently active plan"""
if SESSION_KEY_PLAN in request.session:
del request.session[SESSION_KEY_PLAN]
LOGGER.debug("Canceled current plan")
return redirect("passbook_core:overview")
class ToDefaultFlow(View):
"""Redirect to default flow matching by designation"""
designation: Optional[FlowDesignation] = None
def dispatch(self, request: HttpRequest) -> HttpResponse:
flow = Flow.with_policy(request, designation=self.designation)
if not flow:
raise Http404
# If user already has a pending plan, clear it so we don't have to later.
if SESSION_KEY_PLAN in self.request.session:
plan: FlowPlan = self.request.session[SESSION_KEY_PLAN]
if plan.flow_pk != flow.pk.hex:
LOGGER.warning(
"f(def): Found existing plan for other flow, deleteing plan",
flow_slug=flow.slug,
)
del self.request.session[SESSION_KEY_PLAN]
return redirect_with_qs(
"passbook_flows:flow-executor-shell", request.GET, flow_slug=flow.slug
)
def to_stage_response(request: HttpRequest, source: HttpResponse) -> HttpResponse:
"""Convert normal HttpResponse into JSON Response"""
if isinstance(source, HttpResponseRedirect) or source.status_code == 302:
redirect_url = source["Location"]
if request.path != redirect_url:
return JsonResponse({"type": "redirect", "to": redirect_url})
return source
if isinstance(source, TemplateResponse):
return JsonResponse(
{"type": "template", "body": source.render().content.decode("utf-8")}
)
# Check for actual HttpResponse (without isinstance as we dont want to check inheritance)
if source.__class__ == HttpResponse:
return JsonResponse(
{"type": "template", "body": source.content.decode("utf-8")}
)
return source