mrf: simple policy: add the ability to strip avatars and banners from user profiles

config/config.exs

@@ -314,7 +314,9 @@
   federated_timeline_removal: [],
   report_removal: [],
   reject: [],
-  accept: []
+  accept: [],
+  avatar_removal: [],
+  banner_removal: []
 
 config :pleroma, :mrf_keyword,
   reject: [],

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

@@ -104,6 +104,26 @@ defp check_report_removal(%{host: actor_host} = _actor_info, %{"type" => "Flag"}
 
   defp check_report_removal(_actor_info, object), do: {:ok, object}
 
+  defp check_avatar_removal(%{host: actor_host} = _actor_info, %{"icon" => _icon} = object) do
+    if actor_host in Pleroma.Config.get([:mrf_simple, :avatar_removal]) do
+      {:ok, Map.delete(object, "icon")}
+    else
+      {:ok, object}
+    end
+  end
+
+  defp check_avatar_removal(_actor_info, object), do: {:ok, object}
+
+  defp check_banner_removal(%{host: actor_host} = _actor_info, %{"image" => _image} = object) do
+    if actor_host in Pleroma.Config.get([:mrf_simple, :banner_removal]) do
+      {:ok, Map.delete(object, "image")}
+    else
+      {:ok, object}
+    end
+  end
+
+  defp check_banner_removal(_actor_info, object), do: {:ok, object}
+
   @impl true
   def filter(%{"actor" => actor} = object) do
     actor_info = URI.parse(actor)
@@ -120,5 +140,17 @@ def filter(%{"actor" => actor} = object) do
     end
   end
 
+  def filter(%{"id" => actor, "type" => obj_type} = object)
+      when obj_type in ["Application", "Group", "Organization", "Person", "Service"] do
+    actor_info = URI.parse(actor)
+
+    with {:ok, object} <- check_avatar_removal(actor_info, object),
+         {:ok, object} <- check_banner_removal(actor_info, object) do
+      {:ok, object}
+    else
+      _e -> {:reject, nil}
+    end
+  end
+
   def filter(object), do: {:ok, object}
 end