diff --git a/config/config.exs b/config/config.exs
index a92ab574b..ebcbf8b49 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -408,6 +408,12 @@ config :pleroma, :mrf_keyword,
federated_timeline_removal: [],
replace: []
+config :pleroma, :mrf_emoji,
+ remove_url: [],
+ remove_shortcode: [],
+ federated_timeline_removal_url: [],
+ federated_timeline_removal_shortcode: []
+
config :pleroma, :mrf_hashtag,
sensitive: ["nsfw"],
reject: [],
diff --git a/lib/pleroma/web/activity_pub/emoji_policy.ex b/lib/pleroma/web/activity_pub/emoji_policy.ex
new file mode 100644
index 000000000..747e720b6
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/emoji_policy.ex
@@ -0,0 +1,158 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2023 Pleroma Authors
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.EmojiPolicy do
+ require Pleroma.Constants
+
+ @moduledoc "Reject or force-unlisted emojis with certain URLs or names"
+
+ @behaviour Pleroma.Web.ActivityPub.MRF.Policy
+
+ defp config_remove_url do
+ Pleroma.Config.get([:mrf_emoji, :remove_url], [])
+ end
+
+ @impl Pleroma.Web.ActivityPub.MRF.Policy
+ def filter(%{"type" => type, "object" => %{} = object} = message)
+ when type in ["Create", "Update"] do
+ with object <- process_remove(object, :url, config_remove_url()) do
+ {:ok, Map.put(message, "object", object)}
+ end
+ end
+
+ @impl Pleroma.Web.ActivityPub.MRF.Policy
+ def filter(%{"type" => type} = object) when type in Pleroma.Constants.actor_types() do
+ with object <- process_remove(object, :url, config_remove_url()) do
+ {:ok, object}
+ end
+ end
+
+ @impl Pleroma.Web.ActivityPub.MRF.Policy
+ def filter(message) do
+ {:ok, message}
+ end
+
+ defp match_string?(string, pattern) when is_binary(pattern) do
+ string == pattern
+ end
+
+ defp match_string?(string, %Regex{} = pattern) do
+ String.match?(string, pattern)
+ end
+
+ defp match_any?(string, patterns) do
+ Enum.any?(patterns, &match_string?(string, &1))
+ end
+
+ defp process_remove(object, :url, patterns) do
+ processed_tag =
+ Enum.filter(
+ object["tag"],
+ fn
+ %{"type" => "Emoji", "icon" => %{"url" => url}} when is_binary(url) ->
+ not match_any?(url, patterns)
+
+ _ ->
+ true
+ end
+ )
+
+ processed_emoji =
+ if object["emoji"] do
+ object["emoji"]
+ |> Enum.reduce(%{}, fn {name, url}, acc ->
+ if not match_any?(url, patterns) do
+ Map.put(acc, name, url)
+ else
+ acc
+ end
+ end)
+ else
+ nil
+ end
+
+ if processed_emoji do
+ object
+ |> Map.put("tag", processed_tag)
+ |> Map.put("emoji", processed_emoji)
+ else
+ object
+ |> Map.put("tag", processed_tag)
+ end
+ end
+
+ @impl Pleroma.Web.ActivityPub.MRF.Policy
+ def describe do
+ # This horror is needed to convert regex sigils to strings
+ mrf_emoji =
+ Pleroma.Config.get(:mrf_emoji, [])
+ |> Enum.map(fn {key, value} ->
+ {key,
+ Enum.map(value, fn
+ pattern ->
+ if not is_binary(pattern) do
+ inspect(pattern)
+ else
+ pattern
+ end
+ end)}
+ end)
+ |> Enum.into(%{})
+
+ {:ok, %{mrf_emoji: mrf_emoji}}
+ end
+
+ @impl Pleroma.Web.ActivityPub.MRF.Policy
+ def config_description do
+ %{
+ key: :mrf_emoji,
+ related_policy: "Pleroma.Web.ActivityPub.MRF.EmojiPolicy",
+ label: "MRF Emoji",
+ description:
+ "Reject or force-unlisted emojis whose URLs or names match a keyword or [Regex](https://hexdocs.pm/elixir/Regex.html).",
+ children: [
+ %{
+ key: :remove_url,
+ type: {:list, :string},
+ description: """
+ A list of patterns which result in emoji whose URL matches being removed from the message. This will apply to both statuses and user profiles.
+
+ Each pattern can be a string or [Regex](https://hexdocs.pm/elixir/Regex.html) in the format of `~r/PATTERN/`.
+ """,
+ suggestions: ["foo", ~r/foo/iu]
+ },
+ %{
+ key: :remove_shortcode,
+ type: {:list, :string},
+ description: """
+ A list of patterns which result in emoji whose shortcode matches being removed from the message. This will apply to both statuses and user profiles.
+
+ Each pattern can be a string or [Regex](https://hexdocs.pm/elixir/Regex.html) in the format of `~r/PATTERN/`.
+ """,
+ suggestions: ["foo", ~r/foo/iu]
+ },
+ %{
+ key: :federated_timeline_removal_url,
+ type: {:list, :string},
+ description: """
+ A list of patterns which result in message with emojis whose URLs match being removed from federated timelines (a.k.a unlisted). This will apply only to statuses.
+
+ Each pattern can be a string or [Regex](https://hexdocs.pm/elixir/Regex.html) in the format of `~r/PATTERN/`.
+ """,
+ suggestions: ["foo", ~r/foo/iu]
+ },
+ %{
+ key: :federated_timeline_removal_shortcode,
+ type: {:list, :string},
+ description: """
+ A list of patterns which result in message with emojis whose shortcodes match being removed from federated timelines (a.k.a unlisted). This will apply only to statuses.
+
+ Each pattern can be a string or [Regex](https://hexdocs.pm/elixir/Regex.html) in the format of `~r/PATTERN/`.
+ """,
+ suggestions: ["foo", ~r/foo/iu]
+ }
+ ]
+ }
+ end
+end
diff --git a/test/pleroma/web/activity_pub/mrf/emoji_policy_test.exs b/test/pleroma/web/activity_pub/mrf/emoji_policy_test.exs
new file mode 100644
index 000000000..fe1fb338e
--- /dev/null
+++ b/test/pleroma/web/activity_pub/mrf/emoji_policy_test.exs
@@ -0,0 +1,123 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2023 Pleroma Authors
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.EmojiPolicyTest do
+ use Pleroma.DataCase
+
+ alias Pleroma.Web.ActivityPub.MRF
+ alias Pleroma.Web.ActivityPub.MRF.EmojiPolicy
+
+ setup do: clear_config(:mrf_emoji)
+
+ setup do
+ clear_config([:mrf_emoji], %{
+ remove_url: [],
+ remove_shortcode: [],
+ federated_timeline_removal_url: [],
+ federated_timeline_removal_shortcode: []
+ })
+ end
+
+ @emoji_tags [
+ %{
+ "icon" => %{
+ "type" => "Image",
+ "url" => "https://example.org/emoji/biribiri/mikoto_smile2.png"
+ },
+ "id" => "https://example.org/emoji/biribiri/mikoto_smile2.png",
+ "name" => ":mikoto_smile2:",
+ "type" => "Emoji",
+ "updated" => "1970-01-01T00:00:00Z"
+ },
+ %{
+ "icon" => %{
+ "type" => "Image",
+ "url" => "https://example.org/emoji/biribiri/mikoto_smile3.png"
+ },
+ "id" => "https://example.org/emoji/biribiri/mikoto_smile3.png",
+ "name" => ":mikoto_smile3:",
+ "type" => "Emoji",
+ "updated" => "1970-01-01T00:00:00Z"
+ },
+ %{
+ "icon" => %{
+ "type" => "Image",
+ "url" => "https://example.org/emoji/nekomimi_girl_emoji/nekomimi_girl_emoji_007.png"
+ },
+ "id" => "https://example.org/emoji/nekomimi_girl_emoji/nekomimi_girl_emoji_007.png",
+ "name" => ":nekomimi_girl_emoji_007:",
+ "type" => "Emoji",
+ "updated" => "1970-01-01T00:00:00Z"
+ },
+ %{
+ "icon" => %{
+ "type" => "Image",
+ "url" => "https://example.org/test.png"
+ },
+ "id" => "https://example.org/test.png",
+ "name" => ":test:",
+ "type" => "Emoji",
+ "updated" => "1970-01-01T00:00:00Z"
+ }
+ ]
+
+ @misc_tags [%{"type" => "Placeholder"}]
+
+ @user_data %{
+ "type" => "Person",
+ "id" => "https://example.org/placeholder",
+ "name" => "lol",
+ "tag" => @emoji_tags ++ @misc_tags
+ }
+
+ @status_data %{
+ "type" => "Create",
+ "object" => %{
+ "type" => "Note",
+ "id" => "https://example.org/placeholder",
+ "content" => "lol",
+ "tag" => @emoji_tags ++ @misc_tags,
+ "emoji" => %{
+ "mikoto_smile2" => "https://example.org/emoji/biribiri/mikoto_smile2.png",
+ "mikoto_smile3" => "https://example.org/emoji/biribiri/mikoto_smile3.png",
+ "nekomimi_girl_emoji_007" =>
+ "https://example.org/emoji/nekomimi_girl_emoji/nekomimi_girl_emoji_007.png",
+ "test" => "https://example.org/test.png"
+ }
+ }
+ }
+
+ describe "remove_url" do
+ setup do
+ clear_config([:mrf_emoji, :remove_url], [
+ "https://example.org/test.png",
+ ~r{/biribiri/mikoto_smile[23]\.png},
+ "nekomimi_girl_emoji"
+ ])
+
+ :ok
+ end
+
+ test "processes user" do
+ {:ok, filtered} = MRF.filter_one(EmojiPolicy, @user_data)
+
+ expected_tags = [@emoji_tags |> Enum.at(2)] ++ @misc_tags
+
+ assert %{"tag" => ^expected_tags} = filtered
+ end
+
+ test "processes status" do
+ {:ok, filtered} = MRF.filter_one(EmojiPolicy, @status_data)
+
+ expected_tags = [@emoji_tags |> Enum.at(2)] ++ @misc_tags
+
+ expected_emoji = %{
+ "nekomimi_girl_emoji_007" =>
+ "https://example.org/emoji/nekomimi_girl_emoji/nekomimi_girl_emoji_007.png"
+ }
+
+ assert %{"object" => %{"tag" => ^expected_tags, "emoji" => ^expected_emoji}} = filtered
+ end
+ end
+end