Merge branch 'features/mrf-id_filter' into 'develop'

Add id_filter to MRFs

See merge request pleroma/pleroma!3858

changelog.d/mrf-id_filter.add

@@ -0,0 +1 @@
+Add `id_filter` to MRF to filter URLs and their domain prior to fetching

lib/pleroma/object/fetcher.ex

@@ -168,6 +168,7 @@ defmodule Pleroma.Object.Fetcher do
     Logger.debug("Fetching object #{id} via AP")
 
     with {:scheme, true} <- {:scheme, String.starts_with?(id, "http")},
+         {_, true} <- {:mrf, MRF.id_filter(id)},
          {:ok, body} <- get_object(id),
          {:ok, data} <- safe_json_decode(body),
          :ok <- Containment.contain_origin_from_id(id, data) do
@@ -183,6 +184,9 @@ defmodule Pleroma.Object.Fetcher do
       {:error, e} ->
         {:error, e}
 
+      {:mrf, false} ->
+        {:error, {:reject, "Filtered by id"}}
+
       e ->
         {:error, e}
     end

lib/pleroma/web/activity_pub/mrf.ex

@@ -108,6 +108,14 @@ defmodule Pleroma.Web.ActivityPub.MRF do
 
   def filter(%{} = object), do: get_policies() |> filter(object)
 
+  def id_filter(policies, id) when is_binary(id) do
+    policies
+    |> Enum.filter(&function_exported?(&1, :id_filter, 1))
+    |> Enum.all?(& &1.id_filter(id))
+  end
+
+  def id_filter(id) when is_binary(id), do: get_policies() |> id_filter(id)
+
   @impl true
   def pipeline_filter(%{} = message, meta) do
     object = meta[:object_data]

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

@@ -13,6 +13,12 @@ defmodule Pleroma.Web.ActivityPub.MRF.DropPolicy do
     {:reject, object}
   end
 
+  @impl true
+  def id_filter(id) do
+    Logger.debug("REJECTING #{id}")
+    false
+  end
+
   @impl true
   def describe, do: {:ok, %{}}
 end

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

@@ -4,6 +4,7 @@
 
 defmodule Pleroma.Web.ActivityPub.MRF.Policy do
   @callback filter(map()) :: {:ok | :reject, map()}
+  @callback id_filter(String.t()) :: boolean()
   @callback describe() :: {:ok | :error, map()}
   @callback config_description() :: %{
               optional(:children) => [map()],
@@ -13,5 +14,5 @@ defmodule Pleroma.Web.ActivityPub.MRF.Policy do
               description: String.t()
             }
   @callback history_awareness() :: :auto | :manual
-  @optional_callbacks config_description: 0, history_awareness: 0
+  @optional_callbacks config_description: 0, history_awareness: 0, id_filter: 1
 end

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

@@ -191,6 +191,18 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicy do
     |> MRF.instance_list_from_tuples()
   end
 
+  @impl true
+  def id_filter(id) do
+    host_info = URI.parse(id)
+
+    with {:ok, _} <- check_accept(host_info, %{}),
+         {:ok, _} <- check_reject(host_info, %{}) do
+      true
+    else
+      _ -> false
+    end
+  end
+
   @impl true
   def filter(%{"type" => "Delete", "actor" => actor} = object) do
     %{host: actor_host} = URI.parse(actor)

test/pleroma/web/activity_pub/mrf/simple_policy_test.exs

@@ -252,6 +252,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
       remote_message = build_remote_message()
 
       assert SimplePolicy.filter(remote_message) == {:ok, remote_message}
+      assert SimplePolicy.id_filter(remote_message["actor"])
     end
 
     test "activity has a matching host" do
@@ -260,6 +261,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
       remote_message = build_remote_message()
 
       assert {:reject, _} = SimplePolicy.filter(remote_message)
+      refute SimplePolicy.id_filter(remote_message["actor"])
     end
 
     test "activity matches with wildcard domain" do
@@ -268,6 +270,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
       remote_message = build_remote_message()
 
       assert {:reject, _} = SimplePolicy.filter(remote_message)
+      refute SimplePolicy.id_filter(remote_message["actor"])
     end
 
     test "actor has a matching host" do
@@ -276,6 +279,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
       remote_user = build_remote_user()
 
       assert {:reject, _} = SimplePolicy.filter(remote_user)
+      refute SimplePolicy.id_filter(remote_user["id"])
     end
 
     test "reject Announce when object would be rejected" do
@@ -288,6 +292,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
       }
 
       assert {:reject, _} = SimplePolicy.filter(announce)
+      # Note: Non-Applicable for id_filter/1
     end
 
     test "reject by URI object" do
@@ -300,6 +305,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
       }
 
       assert {:reject, _} = SimplePolicy.filter(announce)
+      # Note: Non-Applicable for id_filter/1
     end
   end
 
@@ -370,6 +376,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
 
       assert SimplePolicy.filter(local_message) == {:ok, local_message}
       assert SimplePolicy.filter(remote_message) == {:ok, remote_message}
+      assert SimplePolicy.id_filter(local_message["actor"])
+      assert SimplePolicy.id_filter(remote_message["actor"])
     end
 
     test "is not empty but activity doesn't have a matching host" do
@@ -380,6 +388,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
 
       assert SimplePolicy.filter(local_message) == {:ok, local_message}
       assert {:reject, _} = SimplePolicy.filter(remote_message)
+      assert SimplePolicy.id_filter(local_message["actor"])
+      refute SimplePolicy.id_filter(remote_message["actor"])
     end
 
     test "activity has a matching host" do
@@ -390,6 +400,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
 
       assert SimplePolicy.filter(local_message) == {:ok, local_message}
       assert SimplePolicy.filter(remote_message) == {:ok, remote_message}
+      assert SimplePolicy.id_filter(local_message["actor"])
+      assert SimplePolicy.id_filter(remote_message["actor"])
     end
 
     test "activity matches with wildcard domain" do
@@ -400,6 +412,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
 
       assert SimplePolicy.filter(local_message) == {:ok, local_message}
       assert SimplePolicy.filter(remote_message) == {:ok, remote_message}
+      assert SimplePolicy.id_filter(local_message["actor"])
+      assert SimplePolicy.id_filter(remote_message["actor"])
     end
 
     test "actor has a matching host" do
@@ -408,6 +422,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
       remote_user = build_remote_user()
 
       assert SimplePolicy.filter(remote_user) == {:ok, remote_user}
+      assert SimplePolicy.id_filter(remote_user["id"])
     end
   end