# 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.HTTPSignaturePlug do import Plug.Conn import Phoenix.Controller, only: [get_format: 1, text: 2] require Logger def init(options) do options end def call(%{assigns: %{valid_signature: true}} = conn, _opts) do conn end def call(conn, _opts) do if get_format(conn) == "activity+json" do conn |> maybe_assign_valid_signature() |> maybe_require_signature() else conn end end defp maybe_assign_valid_signature(conn) do if has_signature_header?(conn) do # set (request-target) header to the appropriate value # we also replace the digest header with the one we computed request_target = String.downcase("#{conn.method}") <> " #{conn.request_path}" conn = conn |> put_req_header("(request-target)", request_target) |> case do %{assigns: %{digest: digest}} = conn -> put_req_header(conn, "digest", digest) conn -> conn end assign(conn, :valid_signature, HTTPSignatures.validate_conn(conn)) else Logger.debug("No signature header!") conn end end defp has_signature_header?(conn) do conn |> get_req_header("signature") |> Enum.at(0, false) end defp maybe_require_signature(%{assigns: %{valid_signature: true}} = conn), do: conn defp maybe_require_signature(conn) do if Pleroma.Config.get([:activitypub, :authorized_fetch_mode], false) do conn |> put_status(:unauthorized) |> text("Request not signed") |> halt() else conn end end end