# Pleroma: A lightweight social networking server # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.Object.Containment do @moduledoc """ This module contains some useful functions for containing objects to specific origins and determining those origins. They previously lived in the ActivityPub `Transmogrifier` module. Object containment is an important step in validating remote objects to prevent spoofing, therefore removal of object containment functions is NOT recommended. """ def get_actor(%{"actor" => actor}) when is_binary(actor) do actor end def get_actor(%{"actor" => actor}) when is_list(actor) do if is_binary(Enum.at(actor, 0)) do Enum.at(actor, 0) else Enum.find(actor, fn %{"type" => type} -> type in ["Person", "Service", "Application"] end) |> Map.get("id") end end def get_actor(%{"actor" => %{"id" => id}}) when is_bitstring(id) do id end def get_actor(%{"actor" => nil, "attributedTo" => actor}) when not is_nil(actor) do get_actor(%{"actor" => actor}) end def get_object(%{"object" => id}) when is_binary(id) do id end def get_object(%{"object" => %{"id" => id}}) when is_binary(id) do id end def get_object(_) do nil end # TODO: We explicitly allow 'tag' URIs through, due to references to legacy OStatus # objects being present in the test suite environment. Once these objects are # removed, please also remove this. if Mix.env() == :test do defp compare_uris(_, %URI{scheme: "tag"}), do: :ok end defp compare_uris(%URI{host: host} = _id_uri, %URI{host: host} = _other_uri), do: :ok defp compare_uris(_id_uri, _other_uri), do: :error @doc """ Checks that an imported AP object's actor matches the domain it came from. """ def contain_origin(_id, %{"actor" => nil}), do: :error def contain_origin(id, %{"actor" => _actor} = params) do id_uri = URI.parse(id) actor_uri = URI.parse(get_actor(params)) compare_uris(actor_uri, id_uri) end def contain_origin(id, %{"attributedTo" => actor} = params), do: contain_origin(id, Map.put(params, "actor", actor)) def contain_origin(_id, _data), do: :error def contain_origin_from_id(id, %{"id" => other_id} = _params) when is_binary(other_id) do id_uri = URI.parse(id) other_uri = URI.parse(other_id) compare_uris(id_uri, other_uri) end def contain_origin_from_id(_id, _data), do: :error def contain_child(%{"object" => %{"id" => id, "attributedTo" => _} = object}), do: contain_origin(id, object) def contain_child(_), do: :ok end