if !der.ReadASN1GeneralizedTime(&t) {
			return t, errors.New("x509: malformed GeneralizedTime")
		}
	default:
		return t, errors.New("x509: unsupported time format")
	}
	return t, nil
}

func parseValidity(der cryptobyte.String) (time.Time, time.Time, error) {
	notBefore, err := parseTime(&der)
	if err != nil {
		return time.Time{}, time.Time{}, err
	}
	notAfter, err := parseTime(&der)
	if err != nil {