1 # Pleroma: A lightweight social networking server
2 # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
3 # SPDX-License-Identifier: AGPL-3.0-only
5 defmodule Pleroma.Web.MediaProxy do
10 @base64_opts [padding: false]
12 def url(url) when is_nil(url) or url == "", do: nil
13 def url("/" <> _ = url), do: url
16 if disabled?() or local?(url) or whitelisted?(url) do
23 def preview_url(url) do
24 if disabled?() or whitelisted?(url) do
27 encode_preview_url(url)
31 defp disabled?, do: !Config.get([:media_proxy, :enabled], false)
33 defp local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
35 defp whitelisted?(url) do
36 %{host: domain} = URI.parse(url)
38 mediaproxy_whitelist = Config.get([:media_proxy, :whitelist])
40 upload_base_url_domain =
41 if !is_nil(Config.get([Upload, :base_url])) do
42 [URI.parse(Config.get([Upload, :base_url])).host]
47 whitelist = mediaproxy_whitelist ++ upload_base_url_domain
49 Enum.any?(whitelist, fn pattern ->
50 String.equivalent?(domain, pattern)
54 defp base64_sig64(url) do
55 base64 = Base.url_encode64(url, @base64_opts)
60 |> Base.url_encode64(@base64_opts)
65 def encode_url(url) do
66 {base64, sig64} = base64_sig64(url)
68 build_url(sig64, base64, filename(url))
71 def encode_preview_url(url) do
72 {base64, sig64} = base64_sig64(url)
74 build_preview_url(sig64, base64, filename(url))
77 def decode_url(sig, url) do
78 with {:ok, sig} <- Base.url_decode64(sig, @base64_opts),
79 signature when signature == sig <- signed_url(url) do
80 {:ok, Base.url_decode64!(url, @base64_opts)}
82 _ -> {:error, :invalid_signature}
86 defp signed_url(url) do
87 :crypto.hmac(:sha, Config.get([Web.Endpoint, :secret_key_base]), url)
90 def filename(url_or_path) do
91 if path = URI.parse(url_or_path).path, do: Path.basename(path)
94 defp proxy_url(path, sig_base64, url_base64, filename) do
96 Pleroma.Config.get([:media_proxy, :base_url], Web.base_url()),
106 def build_url(sig_base64, url_base64, filename \\ nil) do
107 proxy_url("proxy", sig_base64, url_base64, filename)
110 def build_preview_url(sig_base64, url_base64, filename \\ nil) do
111 proxy_url("proxy/preview", sig_base64, url_base64, filename)
114 def filename_matches(%{"filename" => _} = _, path, url) do
115 filename = filename(url)
117 if filename && not basename_matches?(path, filename) do
118 {:wrong_filename, filename}
124 def filename_matches(_, _, _), do: :ok
126 defp basename_matches?(path, filename) do
127 basename = Path.basename(path)
128 basename == filename or URI.decode(basename) == filename or URI.encode(basename) == filename