From a40c3aeb689c5674f7ebb4396830a073a28f2e62 Mon Sep 17 00:00:00 2001
From: Jens Langhammer <jens.langhammer@beryju.org>
Date: Fri, 5 Nov 2021 00:53:56 +0100
Subject: [PATCH] core: make group membership lookup respect parent groups
 (upwards)

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>
---
 authentik/core/models.py            | 21 +++++++++++++++
 authentik/core/tests/test_groups.py | 40 +++++++++++++++++++++++++++++
 authentik/policies/models.py        |  6 ++---
 3 files changed, 64 insertions(+), 3 deletions(-)
 create mode 100644 authentik/core/tests/test_groups.py

diff --git a/authentik/core/models.py b/authentik/core/models.py
index e27a104b7..766df053b 100644
--- a/authentik/core/models.py
+++ b/authentik/core/models.py
@@ -81,6 +81,27 @@ class Group(models.Model):
     )
     attributes = models.JSONField(default=dict, blank=True)
 
+    def is_member(self, user: "User") -> bool:
+        """Recursively check if `user` is member of us, or any parent."""
+        query = """
+        WITH RECURSIVE parents AS (
+            SELECT authentik_core_group.*, 0 AS relative_depth
+            FROM authentik_core_group
+            WHERE authentik_core_group.group_uuid = %s
+
+            UNION ALL
+
+            SELECT authentik_core_group.*, parents.relative_depth - 1
+            FROM authentik_core_group,parents
+            WHERE authentik_core_group.parent_id = parents.group_uuid
+        )
+        SELECT group_uuid
+        FROM parents
+        GROUP BY group_uuid;
+        """
+        groups = Group.objects.raw(query, [self.group_uuid])
+        return user.ak_groups.filter(pk__in=[group.pk for group in groups]).exists()
+
     def __str__(self):
         return f"Group {self.name}"
 
diff --git a/authentik/core/tests/test_groups.py b/authentik/core/tests/test_groups.py
new file mode 100644
index 000000000..9d66341f9
--- /dev/null
+++ b/authentik/core/tests/test_groups.py
@@ -0,0 +1,40 @@
+"""group tests"""
+from django.test.testcases import TestCase
+
+from authentik.core.models import Group, User
+
+
+class TestGroups(TestCase):
+    """Test group membership"""
+
+    def test_group_membership_simple(self):
+        """Test simple membership"""
+        user = User.objects.create(username="user")
+        user2 = User.objects.create(username="user2")
+        group = Group.objects.create(name="group")
+        group.users.add(user)
+        self.assertTrue(group.is_member(user))
+        self.assertFalse(group.is_member(user2))
+
+    def test_group_membership_parent(self):
+        """Test parent membership"""
+        user = User.objects.create(username="user")
+        user2 = User.objects.create(username="user2")
+        first = Group.objects.create(name="first")
+        second = Group.objects.create(name="second", parent=first)
+        second.users.add(user)
+        self.assertTrue(first.is_member(user))
+        self.assertFalse(first.is_member(user2))
+
+    def test_group_membership_parent_extra(self):
+        """Test parent membership"""
+        user = User.objects.create(username="user")
+        user2 = User.objects.create(username="user2")
+        first = Group.objects.create(name="first")
+        second = Group.objects.create(name="second", parent=first)
+        third = Group.objects.create(name="third", parent=second)
+        second.users.add(user)
+        self.assertTrue(first.is_member(user))
+        self.assertFalse(first.is_member(user2))
+        self.assertFalse(third.is_member(user))
+        self.assertFalse(third.is_member(user2))
diff --git a/authentik/policies/models.py b/authentik/policies/models.py
index 3a4f30ffa..fa4a77e61 100644
--- a/authentik/policies/models.py
+++ b/authentik/policies/models.py
@@ -65,14 +65,14 @@ class PolicyBinding(SerializerModel):
         # This is quite an ugly hack to prevent pylint from trying
         # to resolve authentik_core.models.Group
         # as python import path
-        "authentik_core." + "Group",
+        "authentik_core.Group",
         on_delete=models.CASCADE,
         default=None,
         null=True,
         blank=True,
     )
     user = models.ForeignKey(
-        "authentik_core." + "User",
+        "authentik_core.User",
         on_delete=models.CASCADE,
         default=None,
         null=True,
@@ -96,7 +96,7 @@ class PolicyBinding(SerializerModel):
             self.policy: Policy
             return self.policy.passes(request)
         if self.group:
-            return PolicyResult(self.group.users.filter(pk=request.user.pk).exists())
+            return PolicyResult(self.group.is_member(request.user))
         if self.user:
             return PolicyResult(request.user == self.user)
         return PolicyResult(False)