akkoma/lib/pleroma/object/containment.ex

73 lines
2.2 KiB
Elixir

# Pleroma: A lightweight social networking server
# Copyright © 2017-2019 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
@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))
if id_uri.host == actor_uri.host || id_uri.scheme == "tag" do
:ok
else
:error
end
end
def contain_origin(id, %{"attributedTo" => actor} = params),
do: contain_origin(id, Map.put(params, "actor", actor))
def contain_origin_from_id(_id, %{"id" => nil}), do: :error
def contain_origin_from_id(id, %{"id" => other_id} = _params) do
id_uri = URI.parse(id)
other_uri = URI.parse(other_id)
# We explicitly allow 'tag' URIs through, due to legacy OStatus objects
# being present in the ActivityPub network.
if id_uri.host == other_uri.host || other_uri.scheme == "tag" do
:ok
else
:error
end
end
def contain_child(%{"object" => %{"id" => id, "attributedTo" => _} = object}),
do: contain_origin(id, object)
def contain_child(_), do: :ok
end