commit: 55742d978d15bba75bcae9c6f2d91afbb77d0dc5
parent: 89fa14f5583b1465db1bad8c1fae2f7c436bf933
Author: kaniini <nenolod@gmail.com>
Date: Fri, 21 Jun 2019 22:56:54 +0000
Merge branch 'feature/mrf-anti-link-spam' into 'develop'
implement anti link spam MRF
See merge request pleroma/pleroma!1307
Diffstat:
4 files changed, 190 insertions(+), 0 deletions(-)
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -62,6 +62,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
- MRF: Support for running subchains.
- Configuration: `skip_thread_containment` option
- Configuration: `rate_limit` option. See `Pleroma.Plugs.RateLimiter` documentation for details.
+- MRF: Support for filtering out likely spam messages by rejecting posts from new users that contain links.
### Changed
- **Breaking:** Configuration: move from Pleroma.Mailer to Pleroma.Emails.Mailer
diff --git a/docs/config.md b/docs/config.md
@@ -90,6 +90,7 @@ config :pleroma, Pleroma.Emails.Mailer,
* `Pleroma.Web.ActivityPub.MRF.SubchainPolicy`: Selectively runs other MRF policies when messages match (see ``:mrf_subchain`` section)
* `Pleroma.Web.ActivityPub.MRF.RejectNonPublic`: Drops posts with non-public visibility settings (See ``:mrf_rejectnonpublic`` section)
* `Pleroma.Web.ActivityPub.MRF.EnsureRePrepended`: Rewrites posts to ensure that replies to posts with subjects do not have an identical subject and instead begin with re:.
+ * `Pleroma.Web.ActivityPub.MRF.AntiLinkSpamPolicy`: Rejects posts from likely spambots by rejecting posts from new users that contain links.
* `public`: Makes the client API in authentificated mode-only except for user-profiles. Useful for disabling the Local Timeline and The Whole Known Network.
* `quarantined_instances`: List of ActivityPub instances where private(DMs, followers-only) activities will not be send.
* `managed_config`: Whenether the config for pleroma-fe is configured in this config or in ``static/config.json``
diff --git a/lib/pleroma/web/activity_pub/mrf/anti_link_spam_policy.ex b/lib/pleroma/web/activity_pub/mrf/anti_link_spam_policy.ex
@@ -0,0 +1,48 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.AntiLinkSpamPolicy do
+ alias Pleroma.User
+
+ require Logger
+
+ # has the user successfully posted before?
+ defp old_user?(%User{} = u) do
+ u.info.note_count > 0 || u.info.follower_count > 0
+ end
+
+ # does the post contain links?
+ defp contains_links?(%{"content" => content} = _object) do
+ content
+ |> Floki.filter_out("a.mention,a.hashtag,a[rel~=\"tag\"],a.zrl")
+ |> Floki.attribute("a", "href")
+ |> length() > 0
+ end
+
+ defp contains_links?(_), do: false
+
+ def filter(%{"type" => "Create", "actor" => actor, "object" => object} = message) do
+ with {:ok, %User{} = u} <- User.get_or_fetch_by_ap_id(actor),
+ {:contains_links, true} <- {:contains_links, contains_links?(object)},
+ {:old_user, true} <- {:old_user, old_user?(u)} do
+ {:ok, message}
+ else
+ {:contains_links, false} ->
+ {:ok, message}
+
+ {:old_user, false} ->
+ {:reject, nil}
+
+ {:error, _} ->
+ {:reject, nil}
+
+ e ->
+ Logger.warn("[MRF anti-link-spam] WTF: unhandled error #{inspect(e)}")
+ {:reject, nil}
+ end
+ end
+
+ # in all other cases, pass through
+ def filter(message), do: {:ok, message}
+end
diff --git a/test/web/activity_pub/mrf/anti_link_spam_policy_test.exs b/test/web/activity_pub/mrf/anti_link_spam_policy_test.exs
@@ -0,0 +1,140 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.AntiLinkSpamPolicyTest do
+ use Pleroma.DataCase
+ import Pleroma.Factory
+
+ alias Pleroma.Web.ActivityPub.MRF.AntiLinkSpamPolicy
+
+ @linkless_message %{
+ "type" => "Create",
+ "object" => %{
+ "content" => "hi world!"
+ }
+ }
+
+ @linkful_message %{
+ "type" => "Create",
+ "object" => %{
+ "content" => "<a href='https://example.com'>hi world!</a>"
+ }
+ }
+
+ @response_message %{
+ "type" => "Create",
+ "object" => %{
+ "name" => "yes",
+ "type" => "Answer"
+ }
+ }
+
+ describe "with new user" do
+ test "it allows posts without links" do
+ user = insert(:user)
+
+ assert user.info.note_count == 0
+
+ message =
+ @linkless_message
+ |> Map.put("actor", user.ap_id)
+
+ {:ok, _message} = AntiLinkSpamPolicy.filter(message)
+ end
+
+ test "it disallows posts with links" do
+ user = insert(:user)
+
+ assert user.info.note_count == 0
+
+ message =
+ @linkful_message
+ |> Map.put("actor", user.ap_id)
+
+ {:reject, _} = AntiLinkSpamPolicy.filter(message)
+ end
+ end
+
+ describe "with old user" do
+ test "it allows posts without links" do
+ user = insert(:user, info: %{note_count: 1})
+
+ assert user.info.note_count == 1
+
+ message =
+ @linkless_message
+ |> Map.put("actor", user.ap_id)
+
+ {:ok, _message} = AntiLinkSpamPolicy.filter(message)
+ end
+
+ test "it allows posts with links" do
+ user = insert(:user, info: %{note_count: 1})
+
+ assert user.info.note_count == 1
+
+ message =
+ @linkful_message
+ |> Map.put("actor", user.ap_id)
+
+ {:ok, _message} = AntiLinkSpamPolicy.filter(message)
+ end
+ end
+
+ describe "with followed new user" do
+ test "it allows posts without links" do
+ user = insert(:user, info: %{follower_count: 1})
+
+ assert user.info.follower_count == 1
+
+ message =
+ @linkless_message
+ |> Map.put("actor", user.ap_id)
+
+ {:ok, _message} = AntiLinkSpamPolicy.filter(message)
+ end
+
+ test "it allows posts with links" do
+ user = insert(:user, info: %{follower_count: 1})
+
+ assert user.info.follower_count == 1
+
+ message =
+ @linkful_message
+ |> Map.put("actor", user.ap_id)
+
+ {:ok, _message} = AntiLinkSpamPolicy.filter(message)
+ end
+ end
+
+ describe "with unknown actors" do
+ test "it rejects posts without links" do
+ message =
+ @linkless_message
+ |> Map.put("actor", "http://invalid.actor")
+
+ {:reject, _} = AntiLinkSpamPolicy.filter(message)
+ end
+
+ test "it rejects posts with links" do
+ message =
+ @linkful_message
+ |> Map.put("actor", "http://invalid.actor")
+
+ {:reject, _} = AntiLinkSpamPolicy.filter(message)
+ end
+ end
+
+ describe "with contentless-objects" do
+ test "it does not reject them or error out" do
+ user = insert(:user, info: %{note_count: 1})
+
+ message =
+ @response_message
+ |> Map.put("actor", user.ap_id)
+
+ {:ok, _message} = AntiLinkSpamPolicy.filter(message)
+ end
+ end
+end
