inline int AES_set_decrypt_key(const unsigned char *userKey, const int bits,
AES_KEY *key) {
AES_KEY temp_key;
AES_set_encrypt_key(userKey, bits, &temp_key);
AES_set_decrypt_key_fast(key, &temp_key);
return 0;
}
static int
computeOutputs(const OutputInstructions *ois, int *output,
block **computed_outputmap)
{
assert(output && "output's memory should be allocated");
for (uint16_t i = 0; i < ois->size; ++i) {
AES_KEY key;
block out[2], b_zero, b_one;
OutputInstruction *oi = &ois->output_instruction[i];
// decrypt using comp_block as key
block comp_block = computed_outputmap[oi->gc_id][oi->wire_id];
/* XXX: huh? why does calling AES_set_decrypt_key not work!? */
/* AES_set_decrypt_key(comp_block, &key); */
{
AES_KEY temp_key;
AES_set_encrypt_key(comp_block, &temp_key);
AES_set_decrypt_key_fast(&key, &temp_key);
}
out[0] = oi->labels[0];
out[1] = oi->labels[1];
AES_ecb_decrypt_blks(out, 2, &key);
b_zero = garble_zero_block();
b_one = garble_make_block((uint64_t) 0, (uint64_t) 1); // 000...00001
if (garble_equal(out[0], b_zero) || garble_equal(out[1], b_zero)) {
output[i] = 0;
} else if (garble_equal(out[0], b_one) || garble_equal(out[1], b_one)) {
output[i] = 1;
} else {
fprintf(stderr, "Could not compute output[%d] from (gc_id: %d, wire_id: %d)\n",
i, oi->gc_id, oi->wire_id);
/* assert(false); */
return FAILURE;
}
}
return SUCCESS;
}
