1 # Pleroma: A lightweight social networking server
2 # Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
3 # SPDX-License-Identifier: AGPL-3.0-only
5 defmodule Pleroma.Web.MediaProxy do
6 @base64_opts [padding: false]
12 def url("/" <> _ = url), do: url
15 config = Application.get_env(:pleroma, :media_proxy, [])
16 domain = URI.parse(url).host
19 !Keyword.get(config, :enabled, false) or String.starts_with?(url, Pleroma.Web.base_url()) ->
22 Enum.any?(Pleroma.Config.get([:media_proxy, :whitelist]), fn pattern ->
23 String.equivalent?(domain, pattern)
32 def encode_url(url) do
33 secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
35 # Must preserve `%2F` for compatibility with S3
36 # https://git.pleroma.social/pleroma/pleroma/issues/580
37 replacement = get_replacement(url, ":2F:")
39 # The URL is url-decoded and encoded again to ensure it is correctly encoded and not twice.
42 |> String.replace("%2F", replacement)
45 |> String.replace(replacement, "%2F")
46 |> Base.url_encode64(@base64_opts)
48 sig = :crypto.hmac(:sha, secret, base64)
49 sig64 = sig |> Base.url_encode64(@base64_opts)
51 build_url(sig64, base64, filename(url))
54 def decode_url(sig, url) do
55 secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
56 sig = Base.url_decode64!(sig, @base64_opts)
57 local_sig = :crypto.hmac(:sha, secret, url)
59 if local_sig == sig do
60 {:ok, Base.url_decode64!(url, @base64_opts)}
62 {:error, :invalid_signature}
66 def filename(url_or_path) do
67 if path = URI.parse(url_or_path).path, do: Path.basename(path)
70 def build_url(sig_base64, url_base64, filename \\ nil) do
72 Pleroma.Config.get([:media_proxy, :base_url], Pleroma.Web.base_url()),
78 |> Enum.filter(fn value -> value end)
82 defp get_replacement(url, replacement) do
83 if String.contains?(url, replacement) do
84 get_replacement(url, replacement <> replacement)