283 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			283 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
 | 
						|
from passbook.lib.utils.urls import is_url_absolute, 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:
 | 
						|
            if not is_url_absolute(self.request.GET.get(NEXT_ARG_NAME)):
 | 
						|
                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
 | 
						|
        next_stage = self.plan.next()
 | 
						|
        if not next_stage:
 | 
						|
            LOGGER.debug("f(exec): no more stages, flow is done.")
 | 
						|
            return self._flow_done()
 | 
						|
        self.current_stage = next_stage
 | 
						|
        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)
 | 
						|
 | 
						|
    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"""
 | 
						|
        # 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 = self.request.session.get(SESSION_KEY_GET, {}).get(
 | 
						|
            NEXT_ARG_NAME, "passbook_core:overview"
 | 
						|
        )
 | 
						|
        self.cancel()
 | 
						|
        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
 |