# Pleroma: A lightweight social networking server # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.Web.Plugs.MappedSignatureToIdentityPlug do alias Pleroma.Signature alias Pleroma.User alias Pleroma.Web.ActivityPub.Utils import Plug.Conn require Logger def init(options), do: options defp key_id_from_conn(conn) do with %{"keyId" => key_id} <- HTTPSignatures.signature_for_conn(conn), {:ok, ap_id} <- Signature.key_id_to_actor_id(key_id) do ap_id else _ -> nil end end defp user_from_key_id(conn) do with key_actor_id when is_binary(key_actor_id) <- key_id_from_conn(conn), {:ok, %User{} = user} <- User.get_or_fetch_by_ap_id(key_actor_id) do user else _ -> nil end end def call(%{assigns: %{user: _}} = conn, _opts), do: conn # if this has payload make sure it is signed by the same actor that made it def call(%{assigns: %{valid_signature: true}, params: %{"actor" => actor}} = conn, _opts) do with actor_id <- Utils.get_ap_id(actor), {:user, %User{} = user} <- {:user, user_from_key_id(conn)}, {:user_match, true} <- {:user_match, user.ap_id == actor_id} do assign(conn, :user, user) else {:user_match, false} -> Logger.debug("Failed to map identity from signature (payload actor mismatch)") Logger.debug("key_id=#{inspect(key_id_from_conn(conn))}, actor=#{inspect(actor)}") assign(conn, :valid_signature, false) # remove me once testsuite uses mapped capabilities instead of what we do now {:user, nil} -> Logger.debug("Failed to map identity from signature (lookup failure)") Logger.debug("key_id=#{inspect(key_id_from_conn(conn))}, actor=#{actor}") conn end end # no payload, probably a signed fetch def call(%{assigns: %{valid_signature: true}} = conn, _opts) do with %User{} = user <- user_from_key_id(conn) do assign(conn, :user, user) else _ -> Logger.debug("Failed to map identity from signature (no payload actor mismatch)") Logger.debug("key_id=#{inspect(key_id_from_conn(conn))}") assign(conn, :valid_signature, false) end end # no signature at all def call(conn, _opts), do: conn end