# Pleroma: A lightweight social networking server # Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.Web.MediaProxy.MediaProxyController do use Pleroma.Web, :controller alias Pleroma.Config alias Pleroma.Helpers.MediaHelper alias Pleroma.Helpers.UriHelper alias Pleroma.ReverseProxy alias Pleroma.Web.MediaProxy alias Plug.Conn def remote(conn, %{"sig" => sig64, "url" => url64}) do with {_, true} <- {:enabled, MediaProxy.enabled?()}, {:ok, url} <- MediaProxy.decode_url(sig64, url64), {_, false} <- {:in_banned_urls, MediaProxy.in_banned_urls(url)}, :ok <- MediaProxy.verify_request_path_and_url(conn, url) do ReverseProxy.call(conn, url, media_proxy_opts()) else {:enabled, false} -> send_resp(conn, 404, Conn.Status.reason_phrase(404)) {:in_banned_urls, true} -> send_resp(conn, 404, Conn.Status.reason_phrase(404)) {:error, :invalid_signature} -> send_resp(conn, 403, Conn.Status.reason_phrase(403)) {:wrong_filename, filename} -> redirect(conn, external: MediaProxy.build_url(sig64, url64, filename)) end end def preview(%Conn{} = conn, %{"sig" => sig64, "url" => url64}) do with {_, true} <- {:enabled, MediaProxy.preview_enabled?()}, {:ok, url} <- MediaProxy.decode_url(sig64, url64), :ok <- MediaProxy.verify_request_path_and_url(conn, url) do handle_preview(conn, url) else {:enabled, false} -> send_resp(conn, 404, Conn.Status.reason_phrase(404)) {:error, :invalid_signature} -> send_resp(conn, 403, Conn.Status.reason_phrase(403)) {:wrong_filename, filename} -> redirect(conn, external: MediaProxy.build_preview_url(sig64, url64, filename)) end end defp handle_preview(conn, url) do media_proxy_url = MediaProxy.url(url) with {:ok, %{status: status} = head_response} when status in 200..299 <- Pleroma.HTTP.request("HEAD", media_proxy_url, [], [], name: MyFinch) do content_type = Tesla.get_header(head_response, "content-type") content_length = Tesla.get_header(head_response, "content-length") content_length = content_length && String.to_integer(content_length) static = conn.params["static"] in ["true", true] cond do static and content_type == "image/gif" -> handle_jpeg_preview(conn, media_proxy_url) static -> drop_static_param_and_redirect(conn) content_type == "image/gif" -> redirect(conn, external: media_proxy_url) min_content_length_for_preview() > 0 and content_length > 0 and content_length < min_content_length_for_preview() -> redirect(conn, external: media_proxy_url) true -> handle_preview(content_type, conn, media_proxy_url) end else # If HEAD failed, redirecting to media proxy URI doesn't make much sense; returning an error {_, %{status: status}} -> send_resp(conn, :failed_dependency, "Can't fetch HTTP headers (HTTP #{status}).") {:error, :recv_response_timeout} -> send_resp(conn, :failed_dependency, "HEAD request timeout.") _ -> send_resp(conn, :failed_dependency, "Can't fetch HTTP headers.") end end defp handle_preview("image/png" <> _ = _content_type, conn, media_proxy_url) do handle_png_preview(conn, media_proxy_url) end defp handle_preview("image/" <> _ = _content_type, conn, media_proxy_url) do handle_jpeg_preview(conn, media_proxy_url) end defp handle_preview("video/" <> _ = _content_type, conn, media_proxy_url) do handle_video_preview(conn, media_proxy_url) end defp handle_preview(_unsupported_content_type, conn, media_proxy_url) do fallback_on_preview_error(conn, media_proxy_url) end defp handle_png_preview(conn, media_proxy_url) do quality = Config.get!([:media_preview_proxy, :image_quality]) {thumbnail_max_width, thumbnail_max_height} = thumbnail_max_dimensions() with {:ok, thumbnail_binary} <- MediaHelper.image_resize( media_proxy_url, %{ max_width: thumbnail_max_width, max_height: thumbnail_max_height, quality: quality, format: "png" } ) do conn |> put_preview_response_headers(["image/png", "preview.png"]) |> send_resp(200, thumbnail_binary) else _ -> fallback_on_preview_error(conn, media_proxy_url) end end defp handle_jpeg_preview(conn, media_proxy_url) do quality = Config.get!([:media_preview_proxy, :image_quality]) {thumbnail_max_width, thumbnail_max_height} = thumbnail_max_dimensions() with {:ok, thumbnail_binary} <- MediaHelper.image_resize( media_proxy_url, %{max_width: thumbnail_max_width, max_height: thumbnail_max_height, quality: quality} ) do conn |> put_preview_response_headers() |> send_resp(200, thumbnail_binary) else _ -> fallback_on_preview_error(conn, media_proxy_url) end end defp handle_video_preview(conn, media_proxy_url) do with {:ok, thumbnail_binary} <- MediaHelper.video_framegrab(media_proxy_url) do conn |> put_preview_response_headers() |> send_resp(200, thumbnail_binary) else _ -> fallback_on_preview_error(conn, media_proxy_url) end end defp drop_static_param_and_redirect(conn) do uri_without_static_param = conn |> current_url() |> UriHelper.modify_uri_params(%{}, ["static"]) redirect(conn, external: uri_without_static_param) end defp fallback_on_preview_error(conn, media_proxy_url) do redirect(conn, external: media_proxy_url) end defp put_preview_response_headers( conn, [content_type, filename] = _content_info \\ ["image/jpeg", "preview.jpg"] ) do conn |> put_resp_header("content-type", content_type) |> put_resp_header("content-disposition", "inline; filename=\"#{filename}\"") |> put_resp_header("cache-control", ReverseProxy.default_cache_control_header()) end defp thumbnail_max_dimensions do config = media_preview_proxy_config() thumbnail_max_width = Keyword.fetch!(config, :thumbnail_max_width) thumbnail_max_height = Keyword.fetch!(config, :thumbnail_max_height) {thumbnail_max_width, thumbnail_max_height} end defp min_content_length_for_preview do Keyword.get(media_preview_proxy_config(), :min_content_length, 0) end defp media_preview_proxy_config do Config.get!([:media_preview_proxy]) end defp media_proxy_opts do Config.get([:media_proxy, :proxy_opts], []) end end