From 5e963736cee55aa8f4bb9d9fba451ff3864ddaa8 Mon Sep 17 00:00:00 2001 From: Alex Gleason Date: Sun, 21 May 2023 15:26:02 -0500 Subject: [PATCH] Add AntiMentionSpamPolicy --- .../mrf/anti_mention_spam_policy.ex | 87 +++++++++++++++++++ .../mrf/anti_mention_spam_policy_test.exs | 65 ++++++++++++++ 2 files changed, 152 insertions(+) create mode 100644 lib/pleroma/web/activity_pub/mrf/anti_mention_spam_policy.ex create mode 100644 test/pleroma/web/activity_pub/mrf/anti_mention_spam_policy_test.exs diff --git a/lib/pleroma/web/activity_pub/mrf/anti_mention_spam_policy.ex b/lib/pleroma/web/activity_pub/mrf/anti_mention_spam_policy.ex new file mode 100644 index 000000000..ad97a1552 --- /dev/null +++ b/lib/pleroma/web/activity_pub/mrf/anti_mention_spam_policy.ex @@ -0,0 +1,87 @@ +# Pleroma: A lightweight social networking server +# Copyright © 2017-2022 Pleroma Authors +# SPDX-License-Identifier: AGPL-3.0-only + +defmodule Pleroma.Web.ActivityPub.MRF.AntiMentionSpamPolicy do + alias Pleroma.User + require Pleroma.Constants + + @behaviour Pleroma.Web.ActivityPub.MRF.Policy + + defp user_has_followers?(%User{} = u), do: u.follower_count > 0 + defp user_has_posted?(%User{} = u), do: u.note_count > 0 + + defp user_has_age?(%User{} = u) do + now = NaiveDateTime.utc_now() + diff = u.inserted_at |> NaiveDateTime.diff(now, :second) + diff > :timer.seconds(30) + end + + defp good_reputation?(%User{} = u) do + user_has_age?(u) and user_has_followers?(u) and user_has_posted?(u) + end + + # copied from HellthreadPolicy + defp get_recipient_count(message) do + recipients = (message["to"] || []) ++ (message["cc"] || []) + + follower_collection = + User.get_cached_by_ap_id(message["actor"] || message["attributedTo"]).follower_address + + if Enum.member?(recipients, Pleroma.Constants.as_public()) do + recipients = + recipients + |> List.delete(Pleroma.Constants.as_public()) + |> List.delete(follower_collection) + + {:public, length(recipients)} + else + recipients = + recipients + |> List.delete(follower_collection) + + {:not_public, length(recipients)} + end + end + + defp object_has_recipients?(%{"object" => object} = activity) do + {_, object_count} = get_recipient_count(object) + {_, activity_count} = get_recipient_count(activity) + object_count + activity_count > 0 + end + + defp object_has_recipients?(object) do + {_, count} = get_recipient_count(object) + count > 0 + end + + @impl true + def filter(%{"type" => "Create", "actor" => actor} = activity) do + with {:ok, %User{local: false} = u} <- User.get_or_fetch_by_ap_id(actor), + {:has_mentions, true} <- {:has_mentions, object_has_recipients?(activity)}, + {:good_reputation, true} <- {:good_reputation, good_reputation?(u)} do + {:ok, activity} + else + {:ok, %User{local: true}} -> + {:ok, activity} + + {:has_mentions, false} -> + {:ok, activity} + + {:good_reputation, false} -> + {:reject, "[AntiMentionSpamPolicy] User rejected"} + + {:error, _} -> + {:reject, "[AntiMentionSpamPolicy] Failed to get or fetch user by ap_id"} + + e -> + {:reject, "[AntiMentionSpamPolicy] Unhandled error #{inspect(e)}"} + end + end + + # in all other cases, pass through + def filter(message), do: {:ok, message} + + @impl true + def describe, do: {:ok, %{}} +end diff --git a/test/pleroma/web/activity_pub/mrf/anti_mention_spam_policy_test.exs b/test/pleroma/web/activity_pub/mrf/anti_mention_spam_policy_test.exs new file mode 100644 index 000000000..63947858c --- /dev/null +++ b/test/pleroma/web/activity_pub/mrf/anti_mention_spam_policy_test.exs @@ -0,0 +1,65 @@ +# Pleroma: A lightweight social networking server +# Copyright © 2017-2022 Pleroma Authors +# SPDX-License-Identifier: AGPL-3.0-only + +defmodule Pleroma.Web.ActivityPub.MRF.AntiMentionSpamPolicyTest do + use Pleroma.DataCase + import Pleroma.Factory + alias Pleroma.Web.ActivityPub.MRF.AntiMentionSpamPolicy + + test "it allows posts without mentions" do + user = insert(:user, local: false) + assert user.note_count == 0 + + message = %{ + "type" => "Create", + "actor" => user.ap_id + } + + {:ok, _message} = AntiMentionSpamPolicy.filter(message) + end + + test "it allows posts from users with followers, posts, and age" do + user = + insert(:user, + local: false, + follower_count: 1, + note_count: 1, + inserted_at: ~N[1970-01-01 00:00:00] + ) + + message = %{ + "type" => "Create", + "actor" => user.ap_id + } + + {:ok, _message} = AntiMentionSpamPolicy.filter(message) + end + + test "it allows posts from local users" do + user = insert(:user, local: true) + + message = %{ + "type" => "Create", + "actor" => user.ap_id + } + + {:ok, _message} = AntiMentionSpamPolicy.filter(message) + end + + test "it rejects posts with mentions from users without followers" do + user = insert(:user, local: false, follower_count: 0) + + message = %{ + "type" => "Create", + "actor" => user.ap_id, + "object" => %{ + "to" => ["https://pleroma.soykaf.com/users/1"], + "cc" => ["https://pleroma.soykaf.com/users/1"], + "actor" => user.ap_id + } + } + + {:reject, _message} = AntiMentionSpamPolicy.filter(message) + end +end