stages/email: improve error handling for incorrect template syntax (#7758)

* stages/email: improve error handling for incorrect template syntax

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

* add tests

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

---------

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

authentik/core/api/sources.py

@@ -38,7 +38,7 @@ class SourceSerializer(ModelSerializer, MetaNameSerializer):
 
     managed = ReadOnlyField()
     component = SerializerMethodField()
-    icon = ReadOnlyField(source="get_icon")
+    icon = ReadOnlyField(source="icon_url")
 
     def get_component(self, obj: Source) -> str:
         """Get object component so that we know how to edit the object"""

authentik/flows/stage.py

@@ -167,7 +167,11 @@ class ChallengeStageView(StageView):
                 stage_type=self.__class__.__name__, method="get_challenge"
             ).time(),
         ):
-            challenge = self.get_challenge(*args, **kwargs)
+            try:
+                challenge = self.get_challenge(*args, **kwargs)
+            except StageInvalidException as exc:
+                self.logger.debug("Got StageInvalidException", exc=exc)
+                return self.executor.stage_invalid()
         with Hub.current.start_span(
             op="authentik.flow.stage._get_challenge",
             description=self.__class__.__name__,

authentik/stages/email/stage.py

@@ -5,6 +5,7 @@ from uuid import uuid4
 from django.contrib import messages
 from django.http import HttpRequest, HttpResponse
 from django.http.request import QueryDict
+from django.template.exceptions import TemplateSyntaxError
 from django.urls import reverse
 from django.utils.text import slugify
 from django.utils.timezone import now
@@ -12,11 +13,14 @@ from django.utils.translation import gettext as _
 from rest_framework.fields import CharField
 from rest_framework.serializers import ValidationError
 
+from authentik.events.models import Event, EventAction
 from authentik.flows.challenge import Challenge, ChallengeResponse, ChallengeTypes
+from authentik.flows.exceptions import StageInvalidException
 from authentik.flows.models import FlowDesignation, FlowToken
 from authentik.flows.planner import PLAN_CONTEXT_IS_RESTORED, PLAN_CONTEXT_PENDING_USER
 from authentik.flows.stage import ChallengeStageView
 from authentik.flows.views.executor import QS_KEY_TOKEN, QS_QUERY
+from authentik.lib.utils.errors import exception_to_string
 from authentik.stages.email.models import EmailStage
 from authentik.stages.email.tasks import send_mails
 from authentik.stages.email.utils import TemplateEmailMessage
@@ -103,18 +107,27 @@ class EmailStageView(ChallengeStageView):
         current_stage: EmailStage = self.executor.current_stage
         token = self.get_token()
         # Send mail to user
-        message = TemplateEmailMessage(
+        try:
-            subject=_(current_stage.subject),
+            message = TemplateEmailMessage(
-            to=[email],
+                subject=_(current_stage.subject),
-            language=pending_user.locale(self.request),
+                to=[email],
-            template_name=current_stage.template,
+                language=pending_user.locale(self.request),
-            template_context={
+                template_name=current_stage.template,
-                "url": self.get_full_url(**{QS_KEY_TOKEN: token.key}),
+                template_context={
-                "user": pending_user,
+                    "url": self.get_full_url(**{QS_KEY_TOKEN: token.key}),
-                "expires": token.expires,
+                    "user": pending_user,
-            },
+                    "expires": token.expires,
-        )
+                },
-        send_mails(current_stage, message)
+            )
+            send_mails(current_stage, message)
+        except TemplateSyntaxError as exc:
+            Event.new(
+                EventAction.CONFIGURATION_ERROR,
+                message=_("Exception occurred while rendering E-mail template"),
+                error=exception_to_string(exc),
+                template=current_stage.template,
+            ).from_http(self.request)
+            raise StageInvalidException from exc
 
     def get(self, request: HttpRequest, *args, **kwargs) -> HttpResponse:
         # Check if the user came back from the email link to verify
@@ -135,7 +148,11 @@ class EmailStageView(ChallengeStageView):
             return self.executor.stage_invalid()
         # Check if we've already sent the initial e-mail
         if PLAN_CONTEXT_EMAIL_SENT not in self.executor.plan.context:
-            self.send_email()
+            try:
+                self.send_email()
+            except StageInvalidException as exc:
+                self.logger.debug("Got StageInvalidException", exc=exc)
+                return self.executor.stage_invalid()
             self.executor.plan.context[PLAN_CONTEXT_EMAIL_SENT] = True
         return super().get(request, *args, **kwargs)
 

authentik/stages/email/tests/test_templates.py

@@ -4,11 +4,20 @@ from pathlib import Path
 from shutil import rmtree
 from tempfile import mkdtemp, mkstemp
 from typing import Any
+from unittest.mock import PropertyMock, patch
 
 from django.conf import settings
-from django.test import TestCase
+from django.core.mail.backends.locmem import EmailBackend
+from django.urls import reverse
 
-from authentik.stages.email.models import get_template_choices
+from authentik.core.tests.utils import create_test_admin_user, create_test_flow
+from authentik.events.models import Event, EventAction
+from authentik.flows.markers import StageMarker
+from authentik.flows.models import FlowDesignation, FlowStageBinding
+from authentik.flows.planner import PLAN_CONTEXT_PENDING_USER, FlowPlan
+from authentik.flows.tests import FlowTestCase
+from authentik.flows.views.executor import SESSION_KEY_PLAN
+from authentik.stages.email.models import EmailStage, get_template_choices
 
 
 def get_templates_setting(temp_dir: str) -> dict[str, Any]:
@@ -18,11 +27,18 @@ def get_templates_setting(temp_dir: str) -> dict[str, Any]:
     return templates_setting
 
 
-class TestEmailStageTemplates(TestCase):
+class TestEmailStageTemplates(FlowTestCase):
     """Email tests"""
 
     def setUp(self) -> None:
-        self.dir = mkdtemp()
+        self.dir = Path(mkdtemp())
+        self.user = create_test_admin_user()
+
+        self.flow = create_test_flow(FlowDesignation.AUTHENTICATION)
+        self.stage = EmailStage.objects.create(
+            name="email",
+        )
+        self.binding = FlowStageBinding.objects.create(target=self.flow, stage=self.stage, order=2)
 
     def tearDown(self) -> None:
         rmtree(self.dir)
@@ -38,3 +54,37 @@ class TestEmailStageTemplates(TestCase):
             self.assertEqual(len(choices), 3)
             unlink(file)
             unlink(file2)
+
+    def test_custom_template_invalid_syntax(self):
+        """Test with custom template"""
+        with open(self.dir / Path("invalid.html"), "w+", encoding="utf-8") as _invalid:
+            _invalid.write("{% blocktranslate %}")
+        with self.settings(TEMPLATES=get_templates_setting(self.dir)):
+            self.stage.template = "invalid.html"
+            plan = FlowPlan(
+                flow_pk=self.flow.pk.hex, bindings=[self.binding], markers=[StageMarker()]
+            )
+            plan.context[PLAN_CONTEXT_PENDING_USER] = self.user
+            session = self.client.session
+            session[SESSION_KEY_PLAN] = plan
+            session.save()
+
+            url = reverse("authentik_api:flow-executor", kwargs={"flow_slug": self.flow.slug})
+            with patch(
+                "authentik.stages.email.models.EmailStage.backend_class",
+                PropertyMock(return_value=EmailBackend),
+            ):
+                response = self.client.get(url)
+                self.assertEqual(response.status_code, 200)
+                self.assertStageResponse(
+                    response,
+                    self.flow,
+                    error_message="Unknown error",
+                )
+                events = Event.objects.filter(action=EventAction.CONFIGURATION_ERROR)
+                self.assertEqual(len(events), 1)
+                event = events.first()
+                self.assertEqual(
+                    event.context["message"], "Exception occurred while rendering E-mail template"
+                )
+                self.assertEqual(event.context["template"], "invalid.html")