code: func Check(d *certdata.Data) *errors.Errors {
  	var e = errors.New(nil)
  
  	gkp := goodkey.NewKeyPolicy()
  	err := gkp.GoodKey(d.Cert.PublicKey)
  	if err != nil {
  		e.Err("Certificate %s", strings.ToLower(err.Error()))
  		return e
  	}
  
  	return e
  }
docs: // Check performs a strict verification on the extension according to the standard(s)