[#2497] Media preview proxy: preview bypass for small images

(basing on Content-Length and Content-Type).
This commit is contained in:
Ivan Tashkinov 2020-09-12 11:20:41 +03:00
parent 32831f371f
commit cd234a5321

View file

@ -11,6 +11,8 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyController do
alias Pleroma.Web.MediaProxy alias Pleroma.Web.MediaProxy
alias Plug.Conn alias Plug.Conn
@min_content_length_for_preview 100 * 1024
def remote(conn, %{"sig" => sig64, "url" => url64}) do def remote(conn, %{"sig" => sig64, "url" => url64}) do
with {_, true} <- {:enabled, MediaProxy.enabled?()}, with {_, true} <- {:enabled, MediaProxy.enabled?()},
{:ok, url} <- MediaProxy.decode_url(sig64, url64), {:ok, url} <- MediaProxy.decode_url(sig64, url64),
@ -54,8 +56,12 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyController do
with {:ok, %{status: status} = head_response} when status in 200..299 <- with {:ok, %{status: status} = head_response} when status in 200..299 <-
Pleroma.HTTP.request("head", media_proxy_url, [], [], pool: :media) do Pleroma.HTTP.request("head", media_proxy_url, [], [], pool: :media) do
content_type = Tesla.get_header(head_response, "content-type") content_type = Tesla.get_header(head_response, "content-type")
handle_preview(content_type, conn, media_proxy_url) content_length = Tesla.get_header(head_response, "content-length")
content_length = content_length && String.to_integer(content_length)
handle_preview(content_type, content_length, conn, media_proxy_url)
else else
# If HEAD failed, redirecting to media proxy URI doesn't make much sense; returning an error
{_, %{status: status}} -> {_, %{status: status}} ->
send_resp(conn, :failed_dependency, "Can't fetch HTTP headers (HTTP #{status}).") send_resp(conn, :failed_dependency, "Can't fetch HTTP headers (HTTP #{status}).")
@ -69,29 +75,36 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyController do
defp handle_preview( defp handle_preview(
"image/" <> _ = _content_type, "image/" <> _ = _content_type,
_content_length,
%{params: %{"output_format" => "jpeg"}} = conn, %{params: %{"output_format" => "jpeg"}} = conn,
media_proxy_url media_proxy_url
) do ) do
handle_jpeg_preview(conn, media_proxy_url) handle_jpeg_preview(conn, media_proxy_url)
end end
defp handle_preview("image/gif" = _content_type, conn, media_proxy_url) do defp handle_preview("image/gif" = _content_type, _content_length, conn, media_proxy_url) do
redirect(conn, external: media_proxy_url) redirect(conn, external: media_proxy_url)
end end
defp handle_preview("image/png" <> _ = _content_type, conn, media_proxy_url) do defp handle_preview("image/" <> _ = _content_type, content_length, conn, media_proxy_url)
when is_integer(content_length) and content_length > 0 and
content_length < @min_content_length_for_preview do
redirect(conn, external: media_proxy_url)
end
defp handle_preview("image/png" <> _ = _content_type, _content_length, conn, media_proxy_url) do
handle_png_preview(conn, media_proxy_url) handle_png_preview(conn, media_proxy_url)
end end
defp handle_preview("image/" <> _ = _content_type, conn, media_proxy_url) do defp handle_preview("image/" <> _ = _content_type, _content_length, conn, media_proxy_url) do
handle_jpeg_preview(conn, media_proxy_url) handle_jpeg_preview(conn, media_proxy_url)
end end
defp handle_preview("video/" <> _ = _content_type, conn, media_proxy_url) do defp handle_preview("video/" <> _ = _content_type, _content_length, conn, media_proxy_url) do
handle_video_preview(conn, media_proxy_url) handle_video_preview(conn, media_proxy_url)
end end
defp handle_preview(_unsupported_content_type, conn, media_proxy_url) do defp handle_preview(_unsupported_content_type, _content_length, conn, media_proxy_url) do
fallback_on_preview_error(conn, media_proxy_url) fallback_on_preview_error(conn, media_proxy_url)
end end