4 files changed, 180 insertions, 18 deletions
diff --git a/lib/pleroma/web/activity_pub/mrf/follow_bot_policy.ex b/lib/pleroma/web/activity_pub/mrf/follow_bot_policy.ex
new file mode 100644
index 000000000..7307c9c14
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/mrf/follow_bot_policy.ex
@@ -0,0 +1,59 @@
+defmodule Pleroma.Web.ActivityPub.MRF.FollowBotPolicy do
+  @behaviour Pleroma.Web.ActivityPub.MRF
+  alias Pleroma.Config
+  alias Pleroma.User
+  alias Pleroma.Web.CommonAPI
+
+  require Logger
+
+  @impl true
+  def filter(message) do
+    with follower_nickname <- Config.get([:mrf_follow_bot, :follower_nickname]),
+         %User{actor_type: "Service"} = follower <-
+           User.get_cached_by_nickname(follower_nickname),
+         %{"type" => "Create", "object" => %{"type" => "Note"}} <- message do
+      try_follow(follower, message)
+    else
+      nil ->
+        Logger.warn(
+          "#{__MODULE__} skipped because of missing `:mrf_follow_bot, :follower_nickname` configuration, the :follower_nickname
+            account does not exist, or the account is not correctly configured as a bot."
+        )
+
+        {:ok, message}
+
+      _ ->
+        {:ok, message}
+    end
+  end
+
+  defp try_follow(follower, message) do
+    to = Map.get(message, "to", [])
+    cc = Map.get(message, "cc", [])
+    actor = [message["actor"]]
+
+    Enum.concat([to, cc, actor])
+    |> List.flatten()
+    |> Enum.uniq()
+    |> User.get_all_by_ap_id()
+    |> Enum.each(fn user ->
+      with false <- user.local,
+           false <- User.following?(follower, user),
+           false <- User.locked?(user),
+           false <- (user.bio || "") |> String.downcase() |> String.contains?("nobot") do
+        Logger.debug(
+          "#{__MODULE__}: Follow request from #{follower.nickname} to #{user.nickname}"
+        )
+
+        CommonAPI.follow(follower, user)
+      end
+    end)
+
+    {:ok, message}
+  end
+
+  @impl true
+  def describe do
+    {:ok, %{}}
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/mrf/hashtag_policy.ex b/lib/pleroma/web/activity_pub/mrf/hashtag_policy.ex
new file mode 100644
index 000000000..def0c437c
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/mrf/hashtag_policy.ex
@@ -0,0 +1,116 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.HashtagPolicy do
+  require Pleroma.Constants
+
+  alias Pleroma.Config
+  alias Pleroma.Object
+
+  @moduledoc """
+  Reject, TWKN-remove or Set-Sensitive messsages with specific hashtags (without the leading #)
+
+  Note: This MRF Policy is always enabled, if you want to disable it you have to set empty lists.
+  """
+
+  @behaviour Pleroma.Web.ActivityPub.MRF
+
+  defp check_reject(message, hashtags) do
+    if Enum.any?(Config.get([:mrf_hashtag, :reject]), fn match -> match in hashtags end) do
+      {:reject, "[HashtagPolicy] Matches with rejected keyword"}
+    else
+      {:ok, message}
+    end
+  end
+
+  defp check_ftl_removal(%{"to" => to} = message, hashtags) do
+    if Pleroma.Constants.as_public() in to and
+         Enum.any?(Config.get([:mrf_hashtag, :federated_timeline_removal]), fn match ->
+           match in hashtags
+         end) do
+      to = List.delete(to, Pleroma.Constants.as_public())
+      cc = [Pleroma.Constants.as_public() | message["cc"] || []]
+
+      message =
+        message
+        |> Map.put("to", to)
+        |> Map.put("cc", cc)
+        |> Kernel.put_in(["object", "to"], to)
+        |> Kernel.put_in(["object", "cc"], cc)
+
+      {:ok, message}
+    else
+      {:ok, message}
+    end
+  end
+
+  defp check_ftl_removal(message, _hashtags), do: {:ok, message}
+
+  defp check_sensitive(message, hashtags) do
+    if Enum.any?(Config.get([:mrf_hashtag, :sensitive]), fn match -> match in hashtags end) do
+      {:ok, Kernel.put_in(message, ["object", "sensitive"], true)}
+    else
+      {:ok, message}
+    end
+  end
+
+  @impl true
+  def filter(%{"type" => "Create", "object" => object} = message) do
+    hashtags = Object.hashtags(%Object{data: object})
+
+    if hashtags != [] do
+      with {:ok, message} <- check_reject(message, hashtags),
+           {:ok, message} <- check_ftl_removal(message, hashtags),
+           {:ok, message} <- check_sensitive(message, hashtags) do
+        {:ok, message}
+      end
+    else
+      {:ok, message}
+    end
+  end
+
+  @impl true
+  def filter(message), do: {:ok, message}
+
+  @impl true
+  def describe do
+    mrf_hashtag =
+      Config.get(:mrf_hashtag)
+      |> Enum.into(%{})
+
+    {:ok, %{mrf_hashtag: mrf_hashtag}}
+  end
+
+  @impl true
+  def config_description do
+    %{
+      key: :mrf_hashtag,
+      related_policy: "Pleroma.Web.ActivityPub.MRF.HashtagPolicy",
+      label: "MRF Hashtag",
+      description: @moduledoc,
+      children: [
+        %{
+          key: :reject,
+          type: {:list, :string},
+          description: "A list of hashtags which result in message being rejected.",
+          suggestions: ["foo"]
+        },
+        %{
+          key: :federated_timeline_removal,
+          type: {:list, :string},
+          description:
+            "A list of hashtags which result in message being removed from federated timelines (a.k.a unlisted).",
+          suggestions: ["foo"]
+        },
+        %{
+          key: :sensitive,
+          type: {:list, :string},
+          description:
+            "A list of hashtags which result in message being set as sensitive (a.k.a NSFW/R-18)",
+          suggestions: ["nsfw", "r18"]
+        }
+      ]
+    }
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/mrf/simple_policy.ex b/lib/pleroma/web/activity_pub/mrf/simple_policy.ex
index bb3838d2c..62024c58c 100644
--- a/lib/pleroma/web/activity_pub/mrf/simple_policy.ex
+++ b/lib/pleroma/web/activity_pub/mrf/simple_policy.ex
@@ -64,20 +64,16 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicy do
          %{host: actor_host} = _actor_info,
          %{
            "type" => "Create",
-           "object" => child_object
+           "object" => %{} = _child_object
          } = object
-       )
-       when is_map(child_object) do
+       ) do
     media_nsfw =
       Config.get([:mrf_simple, :media_nsfw])
       |> MRF.subdomains_regex()
 
     object =
       if MRF.subdomain_match?(media_nsfw, actor_host) do
-        tags = (child_object["tag"] || []) ++ ["nsfw"]
-        child_object = Map.put(child_object, "tag", tags)
-        child_object = Map.put(child_object, "sensitive", true)
-        Map.put(object, "object", child_object)
+        Kernel.put_in(object, ["object", "sensitive"], true)
       else
         object
       end
diff --git a/lib/pleroma/web/activity_pub/mrf/tag_policy.ex b/lib/pleroma/web/activity_pub/mrf/tag_policy.ex
index 5739cee63..528093ac0 100644
--- a/lib/pleroma/web/activity_pub/mrf/tag_policy.ex
+++ b/lib/pleroma/web/activity_pub/mrf/tag_policy.ex
@@ -28,20 +28,11 @@ defmodule Pleroma.Web.ActivityPub.MRF.TagPolicy do
          "mrf_tag:media-force-nsfw",
          %{
            "type" => "Create",
-           "object" => %{"attachment" => child_attachment} = object
+           "object" => %{"attachment" => child_attachment}
          } = message
        )
        when length(child_attachment) > 0 do
-    tags = (object["tag"] || []) ++ ["nsfw"]
-
-    object =
-      object
-      |> Map.put("tag", tags)
-      |> Map.put("sensitive", true)
-
-    message = Map.put(message, "object", object)
-
-    {:ok, message}
+    {:ok, Kernel.put_in(message, ["object", "sensitive"], true)}
   end
 
   defp process_tag(