static mp_int* GetRsaInt(RsaKey* key, int idx)
{
    if (idx == 0)
        return &key->n;
    if (idx == 1)
        return &key->e;
    if (idx == 2)
        return &key->d;
    if (idx == 3)
        return &key->p;
    if (idx == 4)
        return &key->q;
    if (idx == 5)
        return &key->dP;
    if (idx == 6)
        return &key->dQ;
    if (idx == 7)
        return &key->u;

    return NULL;
}
static mp_int* GetRsaInt(RsaKey* key, int idx)
{
    if (idx == 0)
        return &key->n;
    if (idx == 1)
        return &key->e;
    if (idx == 2)
        return &key->d;
    if (idx == 3)
        return &key->p;
    if (idx == 4)
        return &key->q;
    if (idx == 5)
        return &key->dP;
    if (idx == 6)
        return &key->dQ;
    if (idx == 7)
        return &key->u;

    return NULL;
}