static void ctr_BCC_init(RAND_DRBG_CTR *ctr)
{
    memset(ctr->KX, 0, 48);
    memset(ctr->bltmp, 0, 16);
    ctr_BCC_block(ctr, ctr->KX, ctr->bltmp);
    ctr->bltmp[3] = 1;
    ctr_BCC_block(ctr, ctr->KX + 16, ctr->bltmp);
    if (ctr->keylen != 16) {
        ctr->bltmp[3] = 2;
        ctr_BCC_block(ctr, ctr->KX + 32, ctr->bltmp);
    }
}