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, [])
17 if !Keyword.get(config, :enabled, false) or String.starts_with?(url, Pleroma.Web.base_url()) do
20 secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
22 # Must preserve `%2F` for compatibility with S3
23 # https://git.pleroma.social/pleroma/pleroma/issues/580
24 replacement = get_replacement(url, ":2F:")
26 # The URL is url-decoded and encoded again to ensure it is correctly encoded and not twice.
29 |> String.replace("%2F", replacement)
32 |> String.replace(replacement, "%2F")
33 |> Base.url_encode64(@base64_opts)
35 sig = :crypto.hmac(:sha, secret, base64)
36 sig64 = sig |> Base.url_encode64(@base64_opts)
38 build_url(sig64, base64, filename(url))
42 def decode_url(sig, url) do
43 secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
44 sig = Base.url_decode64!(sig, @base64_opts)
45 local_sig = :crypto.hmac(:sha, secret, url)
47 if local_sig == sig do
48 {:ok, Base.url_decode64!(url, @base64_opts)}
50 {:error, :invalid_signature}
54 def filename(url_or_path) do
55 if path = URI.parse(url_or_path).path, do: Path.basename(path)
58 def build_url(sig_base64, url_base64, filename \\ nil) do
60 Pleroma.Config.get([:media_proxy, :base_url], Pleroma.Web.base_url()),
66 |> Enum.filter(fn value -> value end)
70 defp get_replacement(url, replacement) do
71 if String.contains?(url, replacement) do
72 get_replacement(url, replacement <> replacement)