if (ctr_mode == TFC_MODE_STREAM) tfe_init_iv(&tfe, key, ctr);
if (ctr_mode == TFC_MODE_XTS) tfc_getrandom(xtskey, sizeof(xtskey));
if (ctr_mode == TFC_MODE_STREAM) tfe_init_iv(&tfe, key, ctr);
if (ctr_mode == TFC_MODE_XTS) tfc_getrandom(xtskey, sizeof(xtskey));