Merge branch 'accept-deletes' into 'develop'

Always accept deletions through SimplePolicy, add :reject_deletes group

See merge request pleroma/pleroma!2371

CHANGELOG.md

@@ -14,6 +14,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - New HTTP adapter [gun](https://github.com/ninenines/gun). Gun adapter requires minimum OTP version of 22.2 otherwise Pleroma won’t start. For hackney OTP update is not required.
 - Mix task to create trusted OAuth App.
 - Notifications: Added `follow_request` notification type (configurable, see `[:notifications, :enable_follow_request_notifications]` setting).
+- Added `:reject_deletes` group to SimplePolicy
 <details>
   <summary>API Changes</summary>
 - Mastodon API: Support for `include_types` in `/api/v1/notifications`.
@@ -23,6 +24,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Fixed
 - Support pagination in conversations API
+- **Breaking**: SimplePolicy `:reject` and `:accept` allow deletions again
 
 ## [unreleased-patch]
 ### Fixed

config/config.exs

@@ -336,7 +336,8 @@
   reject: [],
   accept: [],
   avatar_removal: [],
-  banner_removal: []
+  banner_removal: [],
+  reject_deletes: []
 
 config :pleroma, :mrf_keyword,
   reject: [],

config/description.exs

@@ -1317,13 +1317,13 @@
       %{
         key: :reject,
         type: {:list, :string},
-        description: "List of instances to reject any activities from",
+        description: "List of instances to reject activities from (except deletes)",
         suggestions: ["example.com", "*.example.com"]
       },
       %{
         key: :accept,
         type: {:list, :string},
-        description: "List of instances to accept any activities from",
+        description: "List of instances to only accept activities from (except deletes)",
         suggestions: ["example.com", "*.example.com"]
       },
       %{
@@ -1343,6 +1343,12 @@
         type: {:list, :string},
         description: "List of instances to strip banners from",
         suggestions: ["example.com", "*.example.com"]
+      },
+      %{
+        key: :reject_deletes,
+        type: {:list, :string},
+        description: "List of instances to reject deletions from",
+        suggestions: ["example.com", "*.example.com"]
       }
     ]
   },

docs/configuration/mrf.md

@@ -49,6 +49,7 @@ Once `SimplePolicy` is enabled, you can configure various groups in the `:mrf_si
 * `banner_removal`: Banner 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.
 
 Servers should be configured as lists.
 

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

@@ -148,6 +148,21 @@ defp check_banner_removal(%{host: actor_host} = _actor_info, %{"image" => _image
 
   defp check_banner_removal(_actor_info, object), do: {:ok, object}
 
+  @impl true
+  def filter(%{"type" => "Delete", "actor" => actor} = object) do
+    %{host: actor_host} = URI.parse(actor)
+
+    reject_deletes =
+      Pleroma.Config.get([:mrf_simple, :reject_deletes])
+      |> MRF.subdomains_regex()
+
+    if MRF.subdomain_match?(reject_deletes, actor_host) do
+      {:reject, nil}
+    else
+      {:ok, object}
+    end
+  end
+
   @impl true
   def filter(%{"actor" => actor} = object) do
     actor_info = URI.parse(actor)

test/web/activity_pub/mrf/simple_policy_test.exs

@@ -17,7 +17,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
             reject: [],
             accept: [],
             avatar_removal: [],
-            banner_removal: []
+            banner_removal: [],
+            reject_deletes: []
           )
 
   describe "when :media_removal" do
@@ -382,6 +383,66 @@ test "match with wildcard domain" do
     end
   end
 
+  describe "when :reject_deletes is empty" do
+    setup do: Config.put([:mrf_simple, :reject_deletes], [])
+
+    test "it accepts deletions even from rejected servers" do
+      Config.put([:mrf_simple, :reject], ["remote.instance"])
+
+      deletion_message = build_remote_deletion_message()
+
+      assert SimplePolicy.filter(deletion_message) == {:ok, deletion_message}
+    end
+
+    test "it accepts deletions even from non-whitelisted servers" do
+      Config.put([:mrf_simple, :accept], ["non.matching.remote"])
+
+      deletion_message = build_remote_deletion_message()
+
+      assert SimplePolicy.filter(deletion_message) == {:ok, deletion_message}
+    end
+  end
+
+  describe "when :reject_deletes is not empty but it doesn't have a matching host" do
+    setup do: Config.put([:mrf_simple, :reject_deletes], ["non.matching.remote"])
+
+    test "it accepts deletions even from rejected servers" do
+      Config.put([:mrf_simple, :reject], ["remote.instance"])
+
+      deletion_message = build_remote_deletion_message()
+
+      assert SimplePolicy.filter(deletion_message) == {:ok, deletion_message}
+    end
+
+    test "it accepts deletions even from non-whitelisted servers" do
+      Config.put([:mrf_simple, :accept], ["non.matching.remote"])
+
+      deletion_message = build_remote_deletion_message()
+
+      assert SimplePolicy.filter(deletion_message) == {:ok, deletion_message}
+    end
+  end
+
+  describe "when :reject_deletes has a matching host" do
+    setup do: Config.put([:mrf_simple, :reject_deletes], ["remote.instance"])
+
+    test "it rejects the deletion" do
+      deletion_message = build_remote_deletion_message()
+
+      assert SimplePolicy.filter(deletion_message) == {:reject, nil}
+    end
+  end
+
+  describe "when :reject_deletes match with wildcard domain" do
+    setup do: Config.put([:mrf_simple, :reject_deletes], ["*.remote.instance"])
+
+    test "it rejects the deletion" do
+      deletion_message = build_remote_deletion_message()
+
+      assert SimplePolicy.filter(deletion_message) == {:reject, nil}
+    end
+  end
+
   defp build_local_message do
     %{
       "actor" => "#{Pleroma.Web.base_url()}/users/alice",
@@ -408,4 +469,11 @@ defp build_remote_user do
       "type" => "Person"
     }
   end
+
+  defp build_remote_deletion_message do
+    %{
+      "type" => "Delete",
+      "actor" => "https://remote.instance/users/bob"
+    }
+  end
 end