if (ctr_mode == TFC_MODE_ECB) goto _ctrskip2;
tfc_data_to_words64(&iseek_blocks, sizeof(iseek_blocks));
tf_ctr_set(ctr, &iseek_blocks, sizeof(iseek_blocks));
if (ctr_mode == TFC_MODE_ECB) goto _ctrskip2;
tfc_data_to_words64(&iseek_blocks, sizeof(iseek_blocks));
tf_ctr_set(ctr, &iseek_blocks, sizeof(iseek_blocks));