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authentik/authentik/flows/views.py
Jens Langhammer d75284a587 flows: fix errors which occur during flow execution being sent to sentry malformed
Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>
2021-04-22 20:14:37 +02:00

393 lines
15 KiB
Python

"""authentik multi-stage authentication engine"""
from traceback import format_tb
from typing import Any, Optional
from django.contrib.auth.mixins import LoginRequiredMixin
from django.http import Http404, HttpRequest, HttpResponse, HttpResponseRedirect
from django.http.request import QueryDict
from django.shortcuts import get_object_or_404, redirect
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 View
from drf_yasg import openapi
from drf_yasg.utils import no_body, swagger_auto_schema
from rest_framework.permissions import AllowAny
from rest_framework.views import APIView
from sentry_sdk import capture_exception
from structlog.stdlib import BoundLogger, get_logger
from authentik.core.models import USER_ATTRIBUTE_DEBUG
from authentik.events.models import cleanse_dict
from authentik.flows.challenge import (
AccessDeniedChallenge,
Challenge,
ChallengeResponse,
ChallengeTypes,
HttpChallengeResponse,
RedirectChallenge,
ShellChallenge,
)
from authentik.flows.exceptions import EmptyFlowException, FlowNonApplicableException
from authentik.flows.models import ConfigurableStage, Flow, FlowDesignation, Stage
from authentik.flows.planner import (
PLAN_CONTEXT_PENDING_USER,
PLAN_CONTEXT_REDIRECT,
FlowPlan,
FlowPlanner,
)
from authentik.lib.utils.reflection import class_to_path
from authentik.lib.utils.urls import is_url_absolute, redirect_with_qs
LOGGER = get_logger()
# Argument used to redirect user after login
NEXT_ARG_NAME = "next"
SESSION_KEY_PLAN = "authentik_flows_plan"
SESSION_KEY_APPLICATION_PRE = "authentik_flows_application_pre"
SESSION_KEY_GET = "authentik_flows_get"
@method_decorator(xframe_options_sameorigin, name="dispatch")
class FlowExecutorView(APIView):
"""Stage 1 Flow executor, passing requests to Stage Views"""
permission_classes = [AllowAny]
flow: Flow
plan: Optional[FlowPlan] = None
current_stage: Stage
current_stage_view: View
_logger: BoundLogger
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)
self._logger = get_logger().bind(flow_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:
if not is_url_absolute(self.request.GET.get(NEXT_ARG_NAME)):
self._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 self.stage_invalid(error_message=message)
# pylint: disable=unused-argument
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:
self._logger.warning(
"f(exec): Found existing plan for other flow, deleteing plan",
)
# Existing plan is deleted from session and instance
self.plan = None
self.cancel()
self._logger.debug("f(exec): Continuing existing plan")
# Don't check session again as we've either already loaded the plan or we need to plan
if not self.plan:
self._logger.debug("f(exec): No active Plan found, initiating planner")
try:
self.plan = self._initiate_plan()
except FlowNonApplicableException as exc:
self._logger.warning(
"f(exec): Flow not applicable to current user", exc=exc
)
return to_stage_response(self.request, self.handle_invalid_flow(exc))
except EmptyFlowException as exc:
self._logger.warning("f(exec): Flow is empty", exc=exc)
# To match behaviour with loading an empty flow plan from cache,
# we don't show an error message here, but rather call _flow_done()
return self._flow_done()
# Initial flow request, check if we have an upstream query string passed in
request.session[SESSION_KEY_GET] = QueryDict(request.GET.get("query", ""))
# We don't save the Plan after getting the next stage
# as it hasn't been successfully passed yet
next_stage = self.plan.next(self.request)
if not next_stage:
self._logger.debug("f(exec): no more stages, flow is done.")
return self._flow_done()
self.current_stage = next_stage
self._logger.debug(
"f(exec): Current stage",
current_stage=self.current_stage,
flow_slug=self.flow.slug,
)
stage_cls = 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)
@swagger_auto_schema(
responses={
200: Challenge(),
404: "No Token found", # This error can be raised by the email stage
},
request_body=no_body,
manual_parameters=[
openapi.Parameter(
"query",
openapi.IN_QUERY,
required=True,
description="Querystring as received",
type=openapi.TYPE_STRING,
)
],
operation_id="flows_executor_get",
)
def get(self, request: HttpRequest, *args, **kwargs) -> HttpResponse:
"""Get the next pending challenge from the currently active flow."""
self._logger.debug(
"f(exec): Passing GET",
view_class=class_to_path(self.current_stage_view.__class__),
stage=self.current_stage,
)
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
capture_exception(exc)
self._logger.warning(exc)
return to_stage_response(request, FlowErrorResponse(request, exc))
@swagger_auto_schema(
responses={200: Challenge()},
request_body=ChallengeResponse(),
manual_parameters=[
openapi.Parameter(
"query",
openapi.IN_QUERY,
required=True,
description="Querystring as received",
type=openapi.TYPE_STRING,
)
],
operation_id="flows_executor_solve",
)
def post(self, request: HttpRequest, *args, **kwargs) -> HttpResponse:
"""Solve the previously retrieved challenge and advanced to the next stage."""
self._logger.debug(
"f(exec): Passing POST",
view_class=class_to_path(self.current_stage_view.__class__),
stage=self.current_stage,
)
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
capture_exception(exc)
self._logger.warning(exc)
return to_stage_response(request, FlowErrorResponse(request, exc))
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"""
# Since this is wrapped by the ExecutorShell, the next argument is saved in the session
# extract the next param before cancel as that cleans it
next_param = None
if self.plan:
next_param = self.plan.context.get(PLAN_CONTEXT_REDIRECT)
if not next_param:
next_param = self.request.session.get(SESSION_KEY_GET, {}).get(
NEXT_ARG_NAME, "authentik_core:root-redirect"
)
self.cancel()
return to_stage_response(self.request, redirect_with_qs(next_param))
def stage_ok(self) -> HttpResponse:
"""Callback called by stages upon successful completion.
Persists updated plan and context to session."""
self._logger.debug(
"f(exec): Stage ok",
stage_class=class_to_path(self.current_stage_view.__class__),
)
self.plan.pop()
self.request.session[SESSION_KEY_PLAN] = self.plan
if self.plan.stages:
self._logger.debug(
"f(exec): Continuing with next stage",
reamining=len(self.plan.stages),
)
kwargs = self.kwargs
kwargs.update({"flow_slug": self.flow.slug})
return redirect_with_qs(
"authentik_api:flow-executor", self.request.GET, **kwargs
)
# User passed all stages
self._logger.debug(
"f(exec): User passed all stages",
context=cleanse_dict(self.plan.context),
)
return self._flow_done()
def stage_invalid(self, error_message: Optional[str] = None) -> HttpResponse:
"""Callback used stage when data is correct but a policy denies access
or the user account is disabled.
Optionally, an exception can be passed, which will be shown if the current user
is a superuser."""
self._logger.debug("f(exec): Stage invalid")
self.cancel()
response = HttpChallengeResponse(
AccessDeniedChallenge(
{
"error_message": error_message,
"title": self.flow.title,
"type": ChallengeTypes.NATIVE.value,
"component": "ak-stage-access-denied",
}
)
)
return to_stage_response(self.request, response)
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 FlowErrorResponse(TemplateResponse):
"""Response class when an unhandled error occurs during a stage. Normal users
are shown an error message, superusers are shown a full stacktrace."""
error: Exception
def __init__(self, request: HttpRequest, error: Exception) -> None:
# For some reason pyright complains about keyword argument usage here
# pyright: reportGeneralTypeIssues=false
super().__init__(request=request, template="flows/error.html")
self.error = error
def resolve_context(
self, context: Optional[dict[str, Any]]
) -> Optional[dict[str, Any]]:
if not context:
context = {}
context["error"] = self.error
if self._request.user and self._request.user.is_authenticated:
if self._request.user.is_superuser or self._request.user.attributes.get(
USER_ATTRIBUTE_DEBUG, False
):
context["tb"] = "".join(format_tb(self.error.__traceback__))
return context
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("authentik_core:root-redirect")
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(
"authentik_core:if-flow", 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"]
# Redirects to the same URL usually indicate an Error within a form
if request.get_full_path() == redirect_url:
return source
LOGGER.debug(
"converting to redirect challenge",
to=str(redirect_url),
current=request.path,
)
return HttpChallengeResponse(
RedirectChallenge(
{"type": ChallengeTypes.REDIRECT, "to": str(redirect_url)}
)
)
if isinstance(source, TemplateResponse):
return HttpChallengeResponse(
ShellChallenge(
{
"type": ChallengeTypes.SHELL,
"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 HttpChallengeResponse(
ShellChallenge(
{
"type": ChallengeTypes.SHELL,
"body": source.content.decode("utf-8"),
}
)
)
return source
class ConfigureFlowInitView(LoginRequiredMixin, View):
"""Initiate planner for selected change flow and redirect to flow executor,
or raise Http404 if no configure_flow has been set."""
def get(self, request: HttpRequest, stage_uuid: str) -> HttpResponse:
"""Initiate planner for selected change flow and redirect to flow executor,
or raise Http404 if no configure_flow has been set."""
try:
stage: Stage = Stage.objects.get_subclass(pk=stage_uuid)
except Stage.DoesNotExist as exc:
raise Http404 from exc
if not isinstance(stage, ConfigurableStage):
LOGGER.debug("Stage does not inherit ConfigurableStage", stage=stage)
raise Http404
if not stage.configure_flow:
LOGGER.debug("Stage has no configure_flow set", stage=stage)
raise Http404
plan = FlowPlanner(stage.configure_flow).plan(
request, {PLAN_CONTEXT_PENDING_USER: request.user}
)
request.session[SESSION_KEY_PLAN] = plan
return redirect_with_qs(
"authentik_core:if-flow",
self.request.GET,
flow_slug=stage.configure_flow.slug,
)