Merge branch 'feature/delete-validator' into 'develop'

Move deletions to the common pipeline

Closes #1497

See merge request pleroma/pleroma!2441

lib/mix/tasks/pleroma/user.ex

@@ -8,6 +8,8 @@ defmodule Mix.Tasks.Pleroma.User do
   alias Ecto.Changeset
   alias Pleroma.User
   alias Pleroma.UserInviteToken
+  alias Pleroma.Web.ActivityPub.Builder
+  alias Pleroma.Web.ActivityPub.Pipeline
 
   @shortdoc "Manages Pleroma users"
   @moduledoc File.read!("docs/administration/CLI_tasks/user.md")
@@ -96,8 +98,9 @@ defmodule Mix.Tasks.Pleroma.User do
   def run(["rm", nickname]) do
     start_pleroma()
 
-    with %User{local: true} = user <- User.get_cached_by_nickname(nickname) do
-      User.perform(:delete, user)
+    with %User{local: true} = user <- User.get_cached_by_nickname(nickname),
+         {:ok, delete_data, _} <- Builder.delete(user, user.ap_id),
+         {:ok, _delete, _} <- Pipeline.common_pipeline(delete_data, local: true) do
       shell_info("User #{nickname} deleted.")
     else
       _ -> shell_error("No local user #{nickname}")

lib/pleroma/user.ex

@@ -29,7 +29,9 @@ defmodule Pleroma.User do
   alias Pleroma.UserRelationship
   alias Pleroma.Web
   alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Builder
   alias Pleroma.Web.ActivityPub.ObjectValidators.Types
+  alias Pleroma.Web.ActivityPub.Pipeline
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.CommonAPI
   alias Pleroma.Web.CommonAPI.Utils, as: CommonUtils
@@ -1425,8 +1427,6 @@ defmodule Pleroma.User do
 
   @spec perform(atom(), User.t()) :: {:ok, User.t()}
   def perform(:delete, %User{} = user) do
-    {:ok, _user} = ActivityPub.delete(user)
-
     # Remove all relationships
     user
     |> get_followers()
@@ -1536,21 +1536,23 @@ defmodule Pleroma.User do
     })
   end
 
-  def delete_user_activities(%User{ap_id: ap_id}) do
+  def delete_user_activities(%User{ap_id: ap_id} = user) do
     ap_id
     |> Activity.Queries.by_actor()
     |> RepoStreamer.chunk_stream(50)
-    |> Stream.each(fn activities -> Enum.each(activities, &delete_activity/1) end)
+    |> Stream.each(fn activities ->
+      Enum.each(activities, fn activity -> delete_activity(activity, user) end)
+    end)
     |> Stream.run()
   end
 
-  defp delete_activity(%{data: %{"type" => "Create"}} = activity) do
-    activity
-    |> Object.normalize()
-    |> ActivityPub.delete()
+  defp delete_activity(%{data: %{"type" => "Create", "object" => object}}, user) do
+    {:ok, delete_data, _} = Builder.delete(user, object)
+
+    Pipeline.common_pipeline(delete_data, local: true)
   end
 
-  defp delete_activity(%{data: %{"type" => "Like"}} = activity) do
+  defp delete_activity(%{data: %{"type" => "Like"}} = activity, _user) do
     object = Object.normalize(activity)
 
     activity.actor
@@ -1558,7 +1560,7 @@ defmodule Pleroma.User do
     |> ActivityPub.unlike(object)
   end
 
-  defp delete_activity(%{data: %{"type" => "Announce"}} = activity) do
+  defp delete_activity(%{data: %{"type" => "Announce"}} = activity, _user) do
     object = Object.normalize(activity)
 
     activity.actor
@@ -1566,7 +1568,7 @@ defmodule Pleroma.User do
     |> ActivityPub.unannounce(object)
   end
 
-  defp delete_activity(_activity), do: "Doing nothing"
+  defp delete_activity(_activity, _user), do: "Doing nothing"
 
   def html_filter_policy(%User{no_rich_text: true}) do
     Pleroma.HTML.Scrubber.TwitterText

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -519,67 +519,6 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
-  @spec delete(User.t() | Object.t(), keyword()) :: {:ok, User.t() | Object.t()} | {:error, any()}
-  def delete(entity, options \\ []) do
-    with {:ok, result} <- Repo.transaction(fn -> do_delete(entity, options) end) do
-      result
-    end
-  end
-
-  defp do_delete(%User{ap_id: ap_id, follower_address: follower_address} = user, _) do
-    with data <- %{
-           "to" => [follower_address],
-           "type" => "Delete",
-           "actor" => ap_id,
-           "object" => %{"type" => "Person", "id" => ap_id}
-         },
-         {:ok, activity} <- insert(data, true, true, true),
-         :ok <- maybe_federate(activity) do
-      {:ok, user}
-    end
-  end
-
-  defp do_delete(%Object{data: %{"id" => id, "actor" => actor}} = object, options) do
-    local = Keyword.get(options, :local, true)
-    activity_id = Keyword.get(options, :activity_id, nil)
-    actor = Keyword.get(options, :actor, actor)
-
-    user = User.get_cached_by_ap_id(actor)
-    to = (object.data["to"] || []) ++ (object.data["cc"] || [])
-
-    with create_activity <- Activity.get_create_by_object_ap_id(id),
-         data <-
-           %{
-             "type" => "Delete",
-             "actor" => actor,
-             "object" => id,
-             "to" => to,
-             "deleted_activity_id" => create_activity && create_activity.id
-           }
-           |> maybe_put("id", activity_id),
-         {:ok, activity} <- insert(data, local, false),
-         {:ok, object, _create_activity} <- Object.delete(object),
-         stream_out_participations(object, user),
-         _ <- decrease_replies_count_if_reply(object),
-         {:ok, _actor} <- decrease_note_count_if_public(user, object),
-         :ok <- maybe_federate(activity) do
-      {:ok, activity}
-    else
-      {:error, error} ->
-        Repo.rollback(error)
-    end
-  end
-
-  defp do_delete(%Object{data: %{"type" => "Tombstone", "id" => ap_id}}, _) do
-    activity =
-      ap_id
-      |> Activity.Queries.by_object_id()
-      |> Activity.Queries.by_type("Delete")
-      |> Repo.one()
-
-    {:ok, activity}
-  end
-
   @spec block(User.t(), User.t(), String.t() | nil, boolean()) ::
           {:ok, Activity.t()} | {:error, any()}
   def block(blocker, blocked, activity_id \\ nil, local \\ true) do

lib/pleroma/web/activity_pub/activity_pub_controller.ex

@@ -415,7 +415,8 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
   defp handle_user_activity(%User{} = user, %{"type" => "Delete"} = params) do
     with %Object{} = object <- Object.normalize(params["object"]),
          true <- user.is_moderator || user.ap_id == object.data["actor"],
-         {:ok, delete} <- ActivityPub.delete(object) do
+         {:ok, delete_data, _} <- Builder.delete(user, object.data["id"]),
+         {:ok, delete, _} <- Pipeline.common_pipeline(delete_data, local: true) do
       {:ok, delete}
     else
       _ -> {:error, dgettext("errors", "Can't delete object")}

lib/pleroma/web/activity_pub/builder.ex

@@ -10,6 +10,33 @@ defmodule Pleroma.Web.ActivityPub.Builder do
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.ActivityPub.Visibility
 
+  @spec delete(User.t(), String.t()) :: {:ok, map(), keyword()}
+  def delete(actor, object_id) do
+    object = Object.normalize(object_id, false)
+
+    user = !object && User.get_cached_by_ap_id(object_id)
+
+    to =
+      case {object, user} do
+        {%Object{}, _} ->
+          # We are deleting an object, address everyone who was originally mentioned
+          (object.data["to"] || []) ++ (object.data["cc"] || [])
+
+        {_, %User{follower_address: follower_address}} ->
+          # We are deleting a user, address the followers of that user
+          [follower_address]
+      end
+
+    {:ok,
+     %{
+       "id" => Utils.generate_activity_id(),
+       "actor" => actor.ap_id,
+       "object" => object_id,
+       "to" => to,
+       "type" => "Delete"
+     }, []}
+  end
+
   @spec like(User.t(), Object.t()) :: {:ok, map(), keyword()}
   def like(actor, object) do
     object_actor = User.get_cached_by_ap_id(object.data["actor"])

lib/pleroma/web/activity_pub/object_validator.ex

@@ -11,11 +11,23 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
 
   alias Pleroma.Object
   alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ObjectValidators.DeleteValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.LikeValidator
+  alias Pleroma.Web.ActivityPub.ObjectValidators.Types
 
   @spec validate(map(), keyword()) :: {:ok, map(), keyword()} | {:error, any()}
   def validate(object, meta)
 
+  def validate(%{"type" => "Delete"} = object, meta) do
+    with cng <- DeleteValidator.cast_and_validate(object),
+         do_not_federate <- DeleteValidator.do_not_federate?(cng),
+         {:ok, object} <- Ecto.Changeset.apply_action(cng, :insert) do
+      object = stringify_keys(object)
+      meta = Keyword.put(meta, :do_not_federate, do_not_federate)
+      {:ok, object, meta}
+    end
+  end
+
   def validate(%{"type" => "Like"} = object, meta) do
     with {:ok, object} <-
            object |> LikeValidator.cast_and_validate() |> Ecto.Changeset.apply_action(:insert) do
@@ -24,13 +36,25 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
     end
   end
 
+  def stringify_keys(%{__struct__: _} = object) do
+    object
+    |> Map.from_struct()
+    |> stringify_keys
+  end
+
   def stringify_keys(object) do
     object
     |> Map.new(fn {key, val} -> {to_string(key), val} end)
   end
 
+  def fetch_actor(object) do
+    with {:ok, actor} <- Types.ObjectID.cast(object["actor"]) do
+      User.get_or_fetch_by_ap_id(actor)
+    end
+  end
+
   def fetch_actor_and_object(object) do
-    User.get_or_fetch_by_ap_id(object["actor"])
+    fetch_actor(object)
     Object.normalize(object["object"])
     :ok
   end

lib/pleroma/web/activity_pub/object_validators/common_validations.ex

@@ -8,7 +8,29 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.CommonValidations do
   alias Pleroma.Object
   alias Pleroma.User
 
-  def validate_actor_presence(cng, field_name \\ :actor) do
+  def validate_recipients_presence(cng, fields \\ [:to, :cc]) do
+    non_empty =
+      fields
+      |> Enum.map(fn field -> get_field(cng, field) end)
+      |> Enum.any?(fn
+        [] -> false
+        _ -> true
+      end)
+
+    if non_empty do
+      cng
+    else
+      fields
+      |> Enum.reduce(cng, fn field, cng ->
+        cng
+        |> add_error(field, "no recipients in any field")
+      end)
+    end
+  end
+
+  def validate_actor_presence(cng, options \\ []) do
+    field_name = Keyword.get(options, :field_name, :actor)
+
     cng
     |> validate_change(field_name, fn field_name, actor ->
       if User.get_cached_by_ap_id(actor) do
@@ -19,14 +41,39 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.CommonValidations do
     end)
   end
 
-  def validate_object_presence(cng, field_name \\ :object) do
+  def validate_object_presence(cng, options \\ []) do
+    field_name = Keyword.get(options, :field_name, :object)
+    allowed_types = Keyword.get(options, :allowed_types, false)
+
     cng
-    |> validate_change(field_name, fn field_name, object ->
-      if Object.get_cached_by_ap_id(object) do
-        []
-      else
-        [{field_name, "can't find object"}]
+    |> validate_change(field_name, fn field_name, object_id ->
+      object = Object.get_cached_by_ap_id(object_id)
+
+      cond do
+        !object ->
+          [{field_name, "can't find object"}]
+
+        object && allowed_types && object.data["type"] not in allowed_types ->
+          [{field_name, "object not in allowed types"}]
+
+        true ->
+          []
       end
     end)
   end
+
+  def validate_object_or_user_presence(cng, options \\ []) do
+    field_name = Keyword.get(options, :field_name, :object)
+    options = Keyword.put(options, :field_name, field_name)
+
+    actor_cng =
+      cng
+      |> validate_actor_presence(options)
+
+    object_cng =
+      cng
+      |> validate_object_presence(options)
+
+    if actor_cng.valid?, do: actor_cng, else: object_cng
+  end
 end

lib/pleroma/web/activity_pub/object_validators/delete_validator.ex

@@ -0,0 +1,99 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.DeleteValidator do
+  use Ecto.Schema
+
+  alias Pleroma.Activity
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ObjectValidators.Types
+
+  import Ecto.Changeset
+  import Pleroma.Web.ActivityPub.ObjectValidators.CommonValidations
+
+  @primary_key false
+
+  embedded_schema do
+    field(:id, Types.ObjectID, primary_key: true)
+    field(:type, :string)
+    field(:actor, Types.ObjectID)
+    field(:to, Types.Recipients, default: [])
+    field(:cc, Types.Recipients, default: [])
+    field(:deleted_activity_id, Types.ObjectID)
+    field(:object, Types.ObjectID)
+  end
+
+  def cast_data(data) do
+    %__MODULE__{}
+    |> cast(data, __schema__(:fields))
+  end
+
+  def add_deleted_activity_id(cng) do
+    object =
+      cng
+      |> get_field(:object)
+
+    with %Activity{id: id} <- Activity.get_create_by_object_ap_id(object) do
+      cng
+      |> put_change(:deleted_activity_id, id)
+    else
+      _ -> cng
+    end
+  end
+
+  @deletable_types ~w{
+    Answer
+    Article
+    Audio
+    Event
+    Note
+    Page
+    Question
+    Video
+  }
+  def validate_data(cng) do
+    cng
+    |> validate_required([:id, :type, :actor, :to, :cc, :object])
+    |> validate_inclusion(:type, ["Delete"])
+    |> validate_actor_presence()
+    |> validate_deletion_rights()
+    |> validate_object_or_user_presence(allowed_types: @deletable_types)
+    |> add_deleted_activity_id()
+  end
+
+  def do_not_federate?(cng) do
+    !same_domain?(cng)
+  end
+
+  defp same_domain?(cng) do
+    actor_uri =
+      cng
+      |> get_field(:actor)
+      |> URI.parse()
+
+    object_uri =
+      cng
+      |> get_field(:object)
+      |> URI.parse()
+
+    object_uri.host == actor_uri.host
+  end
+
+  def validate_deletion_rights(cng) do
+    actor = User.get_cached_by_ap_id(get_field(cng, :actor))
+
+    if User.superuser?(actor) || same_domain?(cng) do
+      cng
+    else
+      cng
+      |> add_error(:actor, "is not allowed to delete object")
+    end
+  end
+
+  def cast_and_validate(data) do
+    data
+    |> cast_data
+    |> validate_data
+  end
+end

lib/pleroma/web/activity_pub/object_validators/like_validator.ex

@@ -20,8 +20,8 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.LikeValidator do
     field(:object, Types.ObjectID)
     field(:actor, Types.ObjectID)
     field(:context, :string)
-    field(:to, {:array, :string}, default: [])
-    field(:cc, {:array, :string}, default: [])
+    field(:to, Types.Recipients, default: [])
+    field(:cc, Types.Recipients, default: [])
   end
 
   def cast_and_validate(data) do

lib/pleroma/web/activity_pub/object_validators/types/recipients.ex

@@ -0,0 +1,34 @@
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.Types.Recipients do
+  use Ecto.Type
+
+  alias Pleroma.Web.ActivityPub.ObjectValidators.Types.ObjectID
+
+  def type, do: {:array, ObjectID}
+
+  def cast(object) when is_binary(object) do
+    cast([object])
+  end
+
+  def cast(data) when is_list(data) do
+    data
+    |> Enum.reduce({:ok, []}, fn element, acc ->
+      case {acc, ObjectID.cast(element)} do
+        {:error, _} -> :error
+        {_, :error} -> :error
+        {{:ok, list}, {:ok, id}} -> {:ok, [id | list]}
+      end
+    end)
+  end
+
+  def cast(_) do
+    :error
+  end
+
+  def dump(data) do
+    {:ok, data}
+  end
+
+  def load(data) do
+    {:ok, data}
+  end
+end

lib/pleroma/web/activity_pub/pipeline.ex

@@ -44,7 +44,9 @@ defmodule Pleroma.Web.ActivityPub.Pipeline do
 
   defp maybe_federate(%Activity{} = activity, meta) do
     with {:ok, local} <- Keyword.fetch(meta, :local) do
-      if local do
+      do_not_federate = meta[:do_not_federate]
+
+      if !do_not_federate && local do
         Federator.publish(activity)
         {:ok, :federated}
       else

lib/pleroma/web/activity_pub/side_effects.ex

@@ -7,6 +7,8 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
   """
   alias Pleroma.Notification
   alias Pleroma.Object
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.Web.ActivityPub.Utils
 
   def handle(object, meta \\ [])
@@ -23,6 +25,49 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
     {:ok, object, meta}
   end
 
+  # Tasks this handles:
+  # - Delete and unpins the create activity
+  # - Replace object with Tombstone
+  # - Set up notification
+  # - Reduce the user note count
+  # - Reduce the reply count
+  # - Stream out the activity
+  def handle(%{data: %{"type" => "Delete", "object" => deleted_object}} = object, meta) do
+    deleted_object =
+      Object.normalize(deleted_object, false) || User.get_cached_by_ap_id(deleted_object)
+
+    result =
+      case deleted_object do
+        %Object{} ->
+          with {:ok, deleted_object, activity} <- Object.delete(deleted_object),
+               %User{} = user <- User.get_cached_by_ap_id(deleted_object.data["actor"]) do
+            User.remove_pinnned_activity(user, activity)
+
+            {:ok, user} = ActivityPub.decrease_note_count_if_public(user, deleted_object)
+
+            if in_reply_to = deleted_object.data["inReplyTo"] do
+              Object.decrease_replies_count(in_reply_to)
+            end
+
+            ActivityPub.stream_out(object)
+            ActivityPub.stream_out_participations(deleted_object, user)
+            :ok
+          end
+
+        %User{} ->
+          with {:ok, _} <- User.delete(deleted_object) do
+            :ok
+          end
+      end
+
+    if result == :ok do
+      Notification.create_notifications(object)
+      {:ok, object, meta}
+    else
+      {:error, result}
+    end
+  end
+
   # Nothing to do
   def handle(object, meta) do
     {:ok, object, meta}

lib/pleroma/web/activity_pub/transmogrifier.ex

@@ -735,36 +735,12 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     end
   end
 
-  # TODO: We presently assume that any actor on the same origin domain as the object being
-  # deleted has the rights to delete that object.  A better way to validate whether or not
-  # the object should be deleted is to refetch the object URI, which should return either
-  # an error or a tombstone.  This would allow us to verify that a deletion actually took
-  # place.
   def handle_incoming(
-        %{"type" => "Delete", "object" => object_id, "actor" => actor, "id" => id} = data,
+        %{"type" => "Delete"} = data,
         _options
       ) do
-    object_id = Utils.get_ap_id(object_id)
-
-    with actor <- Containment.get_actor(data),
-         {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
-         {:ok, object} <- get_obj_helper(object_id),
-         :ok <- Containment.contain_origin(actor.ap_id, object.data),
-         {:ok, activity} <-
-           ActivityPub.delete(object, local: false, activity_id: id, actor: actor.ap_id) do
+    with {:ok, activity, _} <- Pipeline.common_pipeline(data, local: false) do
       {:ok, activity}
-    else
-      nil ->
-        case User.get_cached_by_ap_id(object_id) do
-          %User{ap_id: ^actor} = user ->
-            User.delete(user)
-
-          nil ->
-            :error
-        end
-
-      _e ->
-        :error
     end
   end
 

lib/pleroma/web/activity_pub/utils.ex

@@ -512,7 +512,7 @@ defmodule Pleroma.Web.ActivityPub.Utils do
   #### Announce-related helpers
 
   @doc """
-  Retruns an existing announce activity if the notice has already been announced
+  Returns an existing announce activity if the notice has already been announced
   """
   @spec get_existing_announce(String.t(), map()) :: Activity.t() | nil
   def get_existing_announce(actor, %{data: %{"id" => ap_id}}) do

lib/pleroma/web/admin_api/admin_api_controller.ex

@@ -17,6 +17,8 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
   alias Pleroma.User
   alias Pleroma.UserInviteToken
   alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Builder
+  alias Pleroma.Web.ActivityPub.Pipeline
   alias Pleroma.Web.ActivityPub.Relay
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.AdminAPI.AccountView
@@ -133,23 +135,20 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
 
   action_fallback(:errors)
 
-  def user_delete(%{assigns: %{user: admin}} = conn, %{"nickname" => nickname}) do
-    user = User.get_cached_by_nickname(nickname)
-    User.delete(user)
-
-    ModerationLog.insert_log(%{
-      actor: admin,
-      subject: [user],
-      action: "delete"
-    })
-
-    conn
-    |> json(nickname)
+  def user_delete(conn, %{"nickname" => nickname}) do
+    user_delete(conn, %{"nicknames" => [nickname]})
   end
 
   def user_delete(%{assigns: %{user: admin}} = conn, %{"nicknames" => nicknames}) do
-    users = nicknames |> Enum.map(&User.get_cached_by_nickname/1)
-    User.delete(users)
+    users =
+      nicknames
+      |> Enum.map(&User.get_cached_by_nickname/1)
+
+    users
+    |> Enum.each(fn user ->
+      {:ok, delete_data, _} = Builder.delete(admin, user.ap_id)
+      Pipeline.common_pipeline(delete_data, local: true)
+    end)
 
     ModerationLog.insert_log(%{
       actor: admin,

lib/pleroma/web/common_api/common_api.ex

@@ -79,8 +79,8 @@ defmodule Pleroma.Web.CommonAPI do
            {:find_activity, Activity.get_by_id_with_object(activity_id)},
          %Object{} = object <- Object.normalize(activity),
          true <- User.superuser?(user) || user.ap_id == object.data["actor"],
-         {:ok, _} <- unpin(activity_id, user),
-         {:ok, delete} <- ActivityPub.delete(object) do
+         {:ok, delete_data, _} <- Builder.delete(user, object.data["id"]),
+         {:ok, delete, _} <- Pipeline.common_pipeline(delete_data, local: true) do
       {:ok, delete}
     else
       {:find_activity, _} -> {:error, :not_found}