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 if !enabled?() or local?(url) or whitelisted?(url) do
22 defp enabled?, do: Pleroma.Config.get([:media_proxy, :enabled], false)
24 defp local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
26 defp whitelisted?(url) do
27 %{host: domain} = URI.parse(url)
29 Enum.any?(Pleroma.Config.get([:media_proxy, :whitelist]), fn pattern ->
30 String.equivalent?(domain, pattern)
34 def encode_url(url) do
35 secret = Pleroma.Config.get([Pleroma.Web.Endpoint, :secret_key_base])
36 base64 = Base.url_encode64(url, @base64_opts)
37 sig = :crypto.hmac(:sha, secret, base64)
38 sig64 = sig |> Base.url_encode64(@base64_opts)
40 build_url(sig64, base64, filename(url))
43 def decode_url(sig, url) do
44 secret = Pleroma.Config.get([Pleroma.Web.Endpoint, :secret_key_base])
45 sig = Base.url_decode64!(sig, @base64_opts)
46 local_sig = :crypto.hmac(:sha, secret, url)
48 if local_sig == sig do
49 {:ok, Base.url_decode64!(url, @base64_opts)}
51 {:error, :invalid_signature}
55 def filename(url_or_path) do
56 if path = URI.parse(url_or_path).path, do: Path.basename(path)
59 def build_url(sig_base64, url_base64, filename \\ nil) do
61 Pleroma.Config.get([:media_proxy, :base_url], Pleroma.Web.base_url()),
67 |> Enum.filter(fn value -> value end)