{ fetchurl }:

fetchurl {
  name = "isrg-root-x1.pem";
  url = "https://letsencrypt.org/certs/isrgrootx1.pem";
  sha256 = "sha256-C5+lpZ7tcVwmwQIMcRtPbsQtWLABXhQzejna0wHFr8M=";
}