int wc_ecc_export_private_only(ecc_key* key, byte* out, word32* outLen)
{
    if (out == NULL || outLen == NULL) {
        return BAD_FUNC_ARG;
    }

    return wc_ecc_export_ex(key, NULL, NULL, NULL, NULL, out, outLen,
        WC_TYPE_UNSIGNED_BIN);
}
int wc_ecc_export_private_only(ecc_key* key, byte* out, word32* outLen)
{
    if (out == NULL || outLen == NULL) {
        return BAD_FUNC_ARG;
    }

    return wc_ecc_export_ex(key, NULL, NULL, NULL, NULL, out, outLen,
        WC_TYPE_UNSIGNED_BIN);
}