git.squeep.com Git - akkoma/blob - lib/pleroma/web/media_proxy/media_proxy_controller.ex

   1 # Pleroma: A lightweight social networking server
   2 # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
   3 # SPDX-License-Identifier: AGPL-3.0-only
   4
   5 defmodule Pleroma.Web.MediaProxy.MediaProxyController do
   6   use Pleroma.Web, :controller
   7
   8   alias Pleroma.ReverseProxy
   9   alias Pleroma.Web.MediaProxy
  10
  11   @default_proxy_opts [max_body_length: 25 * 1_048_576, http: [follow_redirect: true]]
  12
  13   def remote(conn, %{"sig" => sig64, "url" => url64} = params) do
  14     with config <- Pleroma.Config.get([:media_proxy], []),
  15          true <- Keyword.get(config, :enabled, false),
  16          {:ok, url} <- MediaProxy.decode_url(sig64, url64),
  17          {_, false} <- {:in_banned_urls, MediaProxy.in_banned_urls(url)},
  18          :ok <- filename_matches(params, conn.request_path, url) do
  19       ReverseProxy.call(conn, url, Keyword.get(config, :proxy_opts, @default_proxy_opts))
  20     else
  21       error when error in [false, {:in_banned_urls, true}] ->
  22         send_resp(conn, 404, Plug.Conn.Status.reason_phrase(404))
  23
  24       {:error, :invalid_signature} ->
  25         send_resp(conn, 403, Plug.Conn.Status.reason_phrase(403))
  26
  27       {:wrong_filename, filename} ->
  28         redirect(conn, external: MediaProxy.build_url(sig64, url64, filename))
  29     end
  30   end
  31
  32   def filename_matches(%{"filename" => _} = _, path, url) do
  33     filename = MediaProxy.filename(url)
  34
  35     if filename && does_not_match(path, filename) do
  36       {:wrong_filename, filename}
  37     else
  38       :ok
  39     end
  40   end
  41
  42   def filename_matches(_, _, _), do: :ok
  43
  44   defp does_not_match(path, filename) do
  45     basename = Path.basename(path)
  46     basename != filename and URI.decode(basename) != filename and URI.encode(basename) != filename
  47   end
  48 end