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