Create MRF.filter_pipeline to inject :object_data when present

CHANGELOG.md

@@ -27,6 +27,12 @@ switched to a new configuration mechanism, however it was not officially removed
 - Welcome Chat messages preventing user registration with MRF Simple Policy applied to the local instance
 - Mastodon API: the public timeline returning an error when the `reply_visibility` parameter is set to `self` for an unauthenticated user
 
+## Unreleased-patch
+
+### Security
+
+- Fix most MRF rules either crashing or not being applied to objects passed into the Common Pipeline (ChatMessage, Question, Answer, Audio, Event)
+
 ## [2.1.1] - 2020-09-08
 
 ### Security

lib/pleroma/web/activity_pub/mrf.ex

@@ -5,16 +5,34 @@
 defmodule Pleroma.Web.ActivityPub.MRF do
   @callback filter(Map.t()) :: {:ok | :reject, Map.t()}
 
-  def filter(policies, %{} = object) do
+  def filter(policies, %{} = message) do
     policies
-    |> Enum.reduce({:ok, object}, fn
+    |> Enum.reduce({:ok, message}, fn
-      policy, {:ok, object} -> policy.filter(object)
+      policy, {:ok, message} -> policy.filter(message)
       _, error -> error
     end)
   end
 
   def filter(%{} = object), do: get_policies() |> filter(object)
 
+  def pipeline_filter(%{} = message, meta) do
+    object = meta[:object_data]
+    ap_id = message["object"]
+
+    if object && ap_id do
+      with {:ok, message} <- filter(Map.put(message, "object", object)) do
+        meta = Keyword.put(meta, :object_data, message["object"])
+        {:ok, Map.put(message, "object", ap_id), meta}
+      else
+        {err, message} -> {err, message, meta}
+      end
+    else
+      {err, message} = filter(message)
+
+      {err, message, meta}
+    end
+  end
+
   def get_policies do
     Pleroma.Config.get([:mrf, :policies], []) |> get_policies()
   end

lib/pleroma/web/activity_pub/mrf/subchain_policy.ex

@@ -28,8 +28,7 @@ def filter(%{"actor" => actor} = message) do
         }"
       )
 
-      subchain
+      MRF.filter(subchain, message)
-      |> MRF.filter(message)
     else
       _e -> {:ok, message}
     end

lib/pleroma/web/activity_pub/pipeline.ex

@@ -26,13 +26,17 @@ def common_pipeline(object, meta) do
 
       {:error, e} ->
         {:error, e}
+
+      {:reject, e} ->
+        {:reject, e}
     end
   end
 
   def do_common_pipeline(object, meta) do
     with {_, {:ok, validated_object, meta}} <-
            {:validate_object, ObjectValidator.validate(object, meta)},
-         {_, {:ok, mrfd_object}} <- {:mrf_object, MRF.filter(validated_object)},
+         {_, {:ok, mrfd_object, meta}} <-
+           {:mrf_object, MRF.pipeline_filter(validated_object, meta)},
          {_, {:ok, activity, meta}} <-
            {:persist_object, ActivityPub.persist(mrfd_object, meta)},
          {_, {:ok, activity, meta}} <-
@@ -40,7 +44,7 @@ def do_common_pipeline(object, meta) do
          {_, {:ok, _}} <- {:federation, maybe_federate(activity, meta)} do
       {:ok, activity, meta}
     else
-      {:mrf_object, {:reject, _}} -> {:ok, nil, meta}
+      {:mrf_object, {:reject, message, _}} -> {:reject, message}
       e -> {:error, e}
     end
   end

test/web/activity_pub/pipeline_test.exs

@@ -26,7 +26,7 @@ test "when given an `object_data` in meta, Federation will receive a the origina
         {
           Pleroma.Web.ActivityPub.MRF,
           [],
-          [filter: fn o -> {:ok, o} end]
+          [pipeline_filter: fn o, m -> {:ok, o, m} end]
         },
         {
           Pleroma.Web.ActivityPub.ActivityPub,
@@ -51,7 +51,7 @@ test "when given an `object_data` in meta, Federation will receive a the origina
                  Pleroma.Web.ActivityPub.Pipeline.common_pipeline(activity, meta)
 
         assert_called(Pleroma.Web.ActivityPub.ObjectValidator.validate(activity, meta))
-        assert_called(Pleroma.Web.ActivityPub.MRF.filter(activity))
+        assert_called(Pleroma.Web.ActivityPub.MRF.pipeline_filter(activity, meta))
         assert_called(Pleroma.Web.ActivityPub.ActivityPub.persist(activity, meta))
         assert_called(Pleroma.Web.ActivityPub.SideEffects.handle(activity, meta))
         refute called(Pleroma.Web.Federator.publish(activity))
@@ -68,7 +68,7 @@ test "it goes through validation, filtering, persisting, side effects and federa
         {
           Pleroma.Web.ActivityPub.MRF,
           [],
-          [filter: fn o -> {:ok, o} end]
+          [pipeline_filter: fn o, m -> {:ok, o, m} end]
         },
         {
           Pleroma.Web.ActivityPub.ActivityPub,
@@ -93,7 +93,7 @@ test "it goes through validation, filtering, persisting, side effects and federa
                  Pleroma.Web.ActivityPub.Pipeline.common_pipeline(activity, meta)
 
         assert_called(Pleroma.Web.ActivityPub.ObjectValidator.validate(activity, meta))
-        assert_called(Pleroma.Web.ActivityPub.MRF.filter(activity))
+        assert_called(Pleroma.Web.ActivityPub.MRF.pipeline_filter(activity, meta))
         assert_called(Pleroma.Web.ActivityPub.ActivityPub.persist(activity, meta))
         assert_called(Pleroma.Web.ActivityPub.SideEffects.handle(activity, meta))
         assert_called(Pleroma.Web.Federator.publish(activity))
@@ -109,7 +109,7 @@ test "it goes through validation, filtering, persisting, side effects without fe
         {
           Pleroma.Web.ActivityPub.MRF,
           [],
-          [filter: fn o -> {:ok, o} end]
+          [pipeline_filter: fn o, m -> {:ok, o, m} end]
         },
         {
           Pleroma.Web.ActivityPub.ActivityPub,
@@ -131,7 +131,7 @@ test "it goes through validation, filtering, persisting, side effects without fe
                  Pleroma.Web.ActivityPub.Pipeline.common_pipeline(activity, meta)
 
         assert_called(Pleroma.Web.ActivityPub.ObjectValidator.validate(activity, meta))
-        assert_called(Pleroma.Web.ActivityPub.MRF.filter(activity))
+        assert_called(Pleroma.Web.ActivityPub.MRF.pipeline_filter(activity, meta))
         assert_called(Pleroma.Web.ActivityPub.ActivityPub.persist(activity, meta))
         assert_called(Pleroma.Web.ActivityPub.SideEffects.handle(activity, meta))
       end
@@ -148,7 +148,7 @@ test "it goes through validation, filtering, persisting, side effects without fe
         {
           Pleroma.Web.ActivityPub.MRF,
           [],
-          [filter: fn o -> {:ok, o} end]
+          [pipeline_filter: fn o, m -> {:ok, o, m} end]
         },
         {
           Pleroma.Web.ActivityPub.ActivityPub,
@@ -170,7 +170,7 @@ test "it goes through validation, filtering, persisting, side effects without fe
                  Pleroma.Web.ActivityPub.Pipeline.common_pipeline(activity, meta)
 
         assert_called(Pleroma.Web.ActivityPub.ObjectValidator.validate(activity, meta))
-        assert_called(Pleroma.Web.ActivityPub.MRF.filter(activity))
+        assert_called(Pleroma.Web.ActivityPub.MRF.pipeline_filter(activity, meta))
         assert_called(Pleroma.Web.ActivityPub.ActivityPub.persist(activity, meta))
         assert_called(Pleroma.Web.ActivityPub.SideEffects.handle(activity, meta))
       end

test/web/pleroma_api/controllers/chat_controller_test.exs

@@ -126,6 +126,23 @@ test "it works with an attachment", %{conn: conn, user: user} do
 
       assert result["attachment"]
     end
+
+    test "gets MRF reason when rejected", %{conn: conn, user: user} do
+      clear_config([:mrf_keyword, :reject], ["GNO"])
+      clear_config([:mrf, :policies], [Pleroma.Web.ActivityPub.MRF.KeywordPolicy])
+
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.get_or_create(user.id, other_user.ap_id)
+
+      result =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/v1/pleroma/chats/#{chat.id}/messages", %{"content" => "GNO/Linux"})
+        |> json_response_and_validate_schema(200)
+
+      assert result == %{}
+    end
   end
 
   describe "DELETE /api/v1/pleroma/chats/:id/messages/:message_id" do