defmodule Pleroma.Web.MediaProxy.MediaProxyController do use Pleroma.Web, :controller alias Pleroma.{Web.MediaProxy, ReverseProxy} @default_proxy_opts [max_body_length: 25 * 1_048_576, http: [follow_redirect: true]] def remote(conn, params = %{"sig" => sig64, "url" => url64}) do with config <- Pleroma.Config.get([:media_proxy], []), true <- Keyword.get(config, :enabled, false), {:ok, url} <- MediaProxy.decode_url(sig64, url64), _filename <- Path.basename(URI.parse(url).path), :ok <- filename_matches(Map.has_key?(params, "filename"), conn.request_path, url) do ReverseProxy.call(conn, url, Keyword.get(config, :proxy_opts, @default_proxy_opts)) else false -> send_resp(conn, 404, Plug.Conn.Status.reason_phrase(404)) {:error, :invalid_signature} -> send_resp(conn, 403, Plug.Conn.Status.reason_phrase(403)) {:wrong_filename, filename} -> redirect(conn, external: MediaProxy.build_url(sig64, url64, filename)) end end def filename_matches(has_filename, path, url) do filename = url |> MediaProxy.filename() |> URI.decode() path = URI.decode(path) cond do has_filename && filename && Path.basename(path) != filename -> {:wrong_filename, filename} true -> :ok end end end