git.squeep.com Git - akkoma/blob - lib/pleroma/web/media_proxy/media_proxy.ex

   1 defmodule Pleroma.Web.MediaProxy do
   2   @base64_opts [padding: false]
   3
   4   def url(nil), do: nil
   5
   6   def url(url = "/" <> _), do: url
   7
   8   def url(url) do
   9     config = Application.get_env(:pleroma, :media_proxy, [])
  10
  11     if !Keyword.get(config, :enabled, false) or String.starts_with?(url, Pleroma.Web.base_url()) do
  12       url
  13     else
  14       secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
  15       base64 = Base.url_encode64(url, @base64_opts)
  16       sig = :crypto.hmac(:sha, secret, base64)
  17       sig64 = sig |> Base.url_encode64(@base64_opts)
  18       Keyword.get(config, :base_url, Pleroma.Web.base_url()) <> "/proxy/#{sig64}/#{base64}"
  19     end
  20   end
  21
  22   def decode_url(sig, url) do
  23     secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
  24     sig = Base.url_decode64!(sig, @base64_opts)
  25     local_sig = :crypto.hmac(:sha, secret, url)
  26
  27     if local_sig == sig do
  28       {:ok, Base.url_decode64!(url, @base64_opts)}
  29     else
  30       {:error, :invalid_signature}
  31     end
  32   end
  33 end