CHANGELOG.md

@@ -11,11 +11,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - handling of GET /api/v1/preferences
 - Akkoma API is now documented
 - ability to auto-approve follow requests from users you are already following
+- The SimplePolicy MRF can now strip user backgrounds from selected remote hosts
 
 ## Changed
 - OTP builds are now built on erlang OTP26
 - The base Phoenix framework is now updated to 1.7
 - An `outbox` field has been added to actor profiles to comply with AP spec
+- User profile backgrounds do now federate with other Akkoma instances and Sharkey
 
 ## Fixed
 - Documentation issue in which a non-existing nginx file was referenced

docs/docs/configuration/cheatsheet.md

@@ -144,6 +144,7 @@ To add configuration to your config file, you can copy it from the base config.
 * `report_removal`: List of instances to reject reports from and the reason for doing so.
 * `avatar_removal`: List of instances to strip avatars from and the reason for doing so.
 * `banner_removal`: List of instances to strip banners from and the reason for doing so.
+* `background_removal`: List of instances to strip user backgrounds from and the reason for doing so.
 * `reject_deletes`: List of instances to reject deletions from and the reason for doing so.
 
 #### :mrf_subchain

docs/docs/configuration/mrf.md

@@ -35,6 +35,7 @@ Once `SimplePolicy` is enabled, you can configure various groups in the `:mrf_si
 * `media_removal`: Servers in this group will have media stripped from incoming messages.
 * `avatar_removal`: Avatars from these servers will be stripped from incoming messages.
 * `banner_removal`: Banner images from these servers will be stripped from incoming messages.
+* `background_removal`: User background images from these servers will be stripped from incoming messages.
 * `report_removal`: Servers in this group will have their reports (flags) rejected.
 * `federated_timeline_removal`: Servers in this group will have their messages unlisted from the public timelines by flipping the `to` and `cc` fields.
 * `reject_deletes`: Deletion requests will be rejected from these servers.

lib/pleroma/user.ex

@@ -382,6 +382,10 @@ def banner_url(user, options \\ []) do
     do_optional_url(user.banner, "#{Endpoint.url()}/images/banner.png", options)
   end
 
+  def background_url(user) do
+    do_optional_url(user.background, nil, no_default: true)
+  end
+
   defp do_optional_url(field, default, options) do
     case field do
       %{"url" => [%{"href" => href} | _]} when is_binary(href) ->
@@ -466,6 +470,7 @@ def remote_user_changeset(struct \\ %User{local: false}, params) do
         :avatar,
         :ap_enabled,
         :banner,
+        :background,
         :is_locked,
         :last_refreshed_at,
         :uri,

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -1603,6 +1603,7 @@ defp object_to_user_data(data, additional) do
       uri: get_actor_url(data["url"]),
       ap_enabled: true,
       banner: normalize_image(data["image"]),
+      background: normalize_image(data["backgroundUrl"]),
       fields: fields,
       emoji: emojis,
       is_locked: is_locked,

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

@@ -178,6 +178,23 @@ defp check_banner_removal(%{host: actor_host} = _actor_info, %{"image" => _image
 
   defp check_banner_removal(_actor_info, object), do: {:ok, object}
 
+  defp check_background_removal(
+         %{host: actor_host} = _actor_info,
+         %{"backgroundUrl" => _bg} = object
+       ) do
+    background_removal =
+      instance_list(:background_removal)
+      |> MRF.subdomains_regex()
+
+    if MRF.subdomain_match?(background_removal, actor_host) do
+      {:ok, Map.delete(object, "backgroundUrl")}
+    else
+      {:ok, object}
+    end
+  end
+
+  defp check_background_removal(_actor_info, object), do: {:ok, object}
+
   defp extract_context_uri(%{"conversation" => "tag:" <> rest}) do
     rest
     |> String.split(",", parts: 2, trim: true)
@@ -283,7 +300,8 @@ def filter(%{"id" => actor, "type" => obj_type} = object)
     with {:ok, _} <- check_accept(actor_info),
          {:ok, _} <- check_reject(actor_info),
          {:ok, object} <- check_avatar_removal(actor_info, object),
-         {:ok, object} <- check_banner_removal(actor_info, object) do
+         {:ok, object} <- check_banner_removal(actor_info, object),
+         {:ok, object} <- check_background_removal(actor_info, object) do
       {:ok, object}
     else
       {:reject, nil} -> {:reject, "[SimplePolicy]"}
@@ -447,6 +465,11 @@ def config_description do
              key: :banner_removal,
              description: "List of instances to strip banners from and the reason for doing so"
            },
+           %{
+             key: :background_removal,
+             description:
+               "List of instances to strip user backgrounds from and the reason for doing so"
+           },
            %{
              key: :reject_deletes,
              description: "List of instances to reject deletions from and the reason for doing so"

lib/pleroma/web/activity_pub/views/user_view.ex

@@ -112,6 +112,8 @@ def render("user.json", %{user: user}) do
     }
     |> Map.merge(maybe_make_image(&User.avatar_url/2, "icon", user))
     |> Map.merge(maybe_make_image(&User.banner_url/2, "image", user))
+    # Yes, the key is named ...Url eventhough it is a whole 'Image' object
+    |> Map.merge(maybe_insert_image("backgroundUrl", User.background_url(user)))
     |> Map.merge(Utils.make_json_ld_header())
   end
 
@@ -287,7 +289,12 @@ def collection(collection, iri, page, show_items \\ true, total \\ nil) do
   end
 
   defp maybe_make_image(func, key, user) do
-    if image = func.(user, no_default: true) do
+    image = func.(user, no_default: true)
+    maybe_insert_image(key, image)
+  end
+
+  defp maybe_insert_image(key, image) do
+    if image do
       %{
         key => %{
           "type" => "Image",

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

@@ -19,6 +19,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
             accept: [],
             avatar_removal: [],
             banner_removal: [],
+            background_removal: [],
             reject_deletes: []
           )
 
@@ -618,6 +619,42 @@ test "match with wildcard domain" do
     end
   end
 
+  describe "when :background_removal" do
+    test "is empty" do
+      clear_config([:mrf_simple, :background_removal], [])
+
+      remote_user = build_remote_user()
+
+      assert SimplePolicy.filter(remote_user) == {:ok, remote_user}
+    end
+
+    test "is not empty but it doesn't have a matching host" do
+      clear_config([:mrf_simple, :background_removal], [{"non.matching.remote", ""}])
+
+      remote_user = build_remote_user()
+
+      assert SimplePolicy.filter(remote_user) == {:ok, remote_user}
+    end
+
+    test "has a matching host" do
+      clear_config([:mrf_simple, :background_removal], [{"remote.instance", ""}])
+
+      remote_user = build_remote_user()
+      {:ok, filtered} = SimplePolicy.filter(remote_user)
+
+      refute filtered["backgroundUrl"]
+    end
+
+    test "match with wildcard domain" do
+      clear_config([:mrf_simple, :background_removal], [{"*.remote.instance", ""}])
+
+      remote_user = build_remote_user()
+      {:ok, filtered} = SimplePolicy.filter(remote_user)
+
+      refute filtered["backgroundUrl"]
+    end
+  end
+
   describe "when :reject_deletes is empty" do
     setup do: clear_config([:mrf_simple, :reject_deletes], [])
 
@@ -701,6 +738,10 @@ defp build_remote_user do
         "url" => "http://example.com/image.jpg",
         "type" => "Image"
       },
+      "backgroundUrl" => %{
+        "url" => "http://example.com/background.jpg",
+        "type" => "Image"
+      },
       "type" => "Person"
     }
   end

test/pleroma/web/activity_pub/side_effects_test.exs

@@ -155,7 +155,13 @@ test "it blocks but does not unfollow if the relevant setting is set", %{
       user = insert(:user, local: false)
 
       {:ok, update_data, []} =
-        Builder.update(user, %{"id" => user.ap_id, "type" => "Person", "name" => "new name!"})
+        Builder.update(user, %{
+          "id" => user.ap_id,
+          "type" => "Person",
+          "name" => "new name!",
+          "icon" => %{"type" => "Image", "url" => "https://example.org/icon.png"},
+          "backgroundUrl" => %{"type" => "Image", "url" => "https://example.org/bg.jxl"}
+        })
 
       {:ok, update, _meta} = ActivityPub.persist(update_data, local: true)
 
@@ -165,7 +171,10 @@ test "it blocks but does not unfollow if the relevant setting is set", %{
     test "it updates the user", %{user: user, update: update} do
       {:ok, _, _} = SideEffects.handle(update)
       user = User.get_by_id(user.id)
+
       assert user.name == "new name!"
+      assert [%{"href" => "https://example.org/icon.png"}] = user.avatar["url"]
+      assert [%{"href" => "https://example.org/bg.jxl"}] = user.background["url"]
     end
 
     test "it uses a given changeset to update", %{user: user, update: update} do

test/pleroma/web/activity_pub/views/user_view_test.exs

@@ -58,16 +58,19 @@ test "Does not add an avatar image if the user hasn't set one" do
     result = UserView.render("user.json", %{user: user})
     refute result["icon"]
     refute result["image"]
+    refute result["backgroundUrl"]
 
     user =
       insert(:user,
         avatar: %{"url" => [%{"href" => "https://someurl"}]},
-        banner: %{"url" => [%{"href" => "https://somebanner"}]}
+        banner: %{"url" => [%{"href" => "https://somebanner"}]},
+        background: %{"url" => [%{"href" => "https://somebackground"}]}
       )
 
     result = UserView.render("user.json", %{user: user})
     assert result["icon"]["url"] == "https://someurl"
     assert result["image"]["url"] == "https://somebanner"
+    assert result["backgroundUrl"]["url"] == "https://somebackground"
   end
 
   test "renders an invisible user with the invisible property set to true" do