X-Git-Url: http://git.squeep.com/?a=blobdiff_plain;f=lib%2Fpleroma%2Fweb%2Fmedia_proxy%2Fmedia_proxy.ex;h=4e01c14e4a765bf0047e2d649f89538413a7441e;hb=0e23138b50f1fdd9ea78df31eec1b3caac905e2c;hp=3bd2affe9e63733727a64ca1839eca27c15a924b;hpb=54e7087ab412a488f8ad7286aef89d313e5e7b14;p=akkoma diff --git a/lib/pleroma/web/media_proxy/media_proxy.ex b/lib/pleroma/web/media_proxy/media_proxy.ex index 3bd2affe9..4e01c14e4 100644 --- a/lib/pleroma/web/media_proxy/media_proxy.ex +++ b/lib/pleroma/web/media_proxy/media_proxy.ex @@ -1,77 +1,143 @@ # Pleroma: A lightweight social networking server -# Copyright © 2017-2019 Pleroma Authors +# Copyright © 2017-2020 Pleroma Authors # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.Web.MediaProxy do - @base64_opts [padding: false] - - def url(nil), do: nil + alias Pleroma.Config + alias Pleroma.Upload + alias Pleroma.Web - def url(""), do: nil + @base64_opts [padding: false] + def url(url) when is_nil(url) or url == "", do: nil def url("/" <> _ = url), do: url def url(url) do - config = Application.get_env(:pleroma, :media_proxy, []) - - if !Keyword.get(config, :enabled, false) or String.starts_with?(url, Pleroma.Web.base_url()) do + if not enabled?() or local?(url) or whitelisted?(url) do url else - secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base] + encode_url(url) + end + end - # Must preserve `%2F` for compatibility with S3 - # https://git.pleroma.social/pleroma/pleroma/issues/580 - replacement = get_replacement(url, ":2F:") + # Note: routing all URLs to preview handler (even local and whitelisted). + # Preview handler will call url/1 on decoded URLs, and applicable ones will detour media proxy. + def preview_url(url) do + if preview_enabled?() do + encode_preview_url(url) + else + url + end + end - # The URL is url-decoded and encoded again to ensure it is correctly encoded and not twice. - base64 = - url - |> String.replace("%2F", replacement) - |> URI.decode() - |> URI.encode() - |> String.replace(replacement, "%2F") - |> Base.url_encode64(@base64_opts) + def enabled?, do: Config.get([:media_proxy, :enabled], false) - sig = :crypto.hmac(:sha, secret, base64) - sig64 = sig |> Base.url_encode64(@base64_opts) + # Note: media proxy must be enabled for media preview proxy in order to load all + # non-local non-whitelisted URLs through it and be sure that body size constraint is preserved. + def preview_enabled?, do: enabled?() and Config.get([:media_preview_proxy, :enabled], false) - build_url(sig64, base64, filename(url)) - end + def local?(url), do: String.starts_with?(url, Pleroma.Web.base_url()) + + def whitelisted?(url) do + %{host: domain} = URI.parse(url) + + mediaproxy_whitelist = Config.get([:media_proxy, :whitelist]) + + upload_base_url_domain = + if !is_nil(Config.get([Upload, :base_url])) do + [URI.parse(Config.get([Upload, :base_url])).host] + else + [] + end + + whitelist = mediaproxy_whitelist ++ upload_base_url_domain + + Enum.any?(whitelist, fn pattern -> + String.equivalent?(domain, pattern) + end) end - def decode_url(sig, url) do - secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base] - sig = Base.url_decode64!(sig, @base64_opts) - local_sig = :crypto.hmac(:sha, secret, url) + defp base64_sig64(url) do + base64 = Base.url_encode64(url, @base64_opts) + + sig64 = + base64 + |> signed_url() + |> Base.url_encode64(@base64_opts) + + {base64, sig64} + end + + def encode_url(url) do + {base64, sig64} = base64_sig64(url) - if local_sig == sig do + build_url(sig64, base64, filename(url)) + end + + def encode_preview_url(url) do + {base64, sig64} = base64_sig64(url) + + build_preview_url(sig64, base64, filename(url)) + end + + def decode_url(sig, url) do + with {:ok, sig} <- Base.url_decode64(sig, @base64_opts), + signature when signature == sig <- signed_url(url) do {:ok, Base.url_decode64!(url, @base64_opts)} else - {:error, :invalid_signature} + _ -> {:error, :invalid_signature} end end + defp signed_url(url) do + :crypto.hmac(:sha, Config.get([Web.Endpoint, :secret_key_base]), url) + end + def filename(url_or_path) do if path = URI.parse(url_or_path).path, do: Path.basename(path) end - def build_url(sig_base64, url_base64, filename \\ nil) do + defp proxy_url(path, sig_base64, url_base64, filename) do [ - Pleroma.Config.get([:media_proxy, :base_url], Pleroma.Web.base_url()), - "proxy", + Pleroma.Config.get([:media_proxy, :base_url], Web.base_url()), + path, sig_base64, url_base64, filename ] - |> Enum.filter(fn value -> value end) + |> Enum.filter(& &1) |> Path.join() end - defp get_replacement(url, replacement) do - if String.contains?(url, replacement) do - get_replacement(url, replacement <> replacement) + def build_url(sig_base64, url_base64, filename \\ nil) do + proxy_url("proxy", sig_base64, url_base64, filename) + end + + def build_preview_url(sig_base64, url_base64, filename \\ nil) do + proxy_url("proxy/preview", sig_base64, url_base64, filename) + end + + def verify_request_path_and_url( + %Plug.Conn{params: %{"filename" => _}, request_path: request_path}, + url + ) do + verify_request_path_and_url(request_path, url) + end + + def verify_request_path_and_url(request_path, url) when is_binary(request_path) do + filename = filename(url) + + if filename && not basename_matches?(request_path, filename) do + {:wrong_filename, filename} else - replacement + :ok end end + + def verify_request_path_and_url(_, _), do: :ok + + defp basename_matches?(path, filename) do + basename = Path.basename(path) + basename == filename or URI.decode(basename) == filename or URI.encode(basename) == filename + end end