static int alice_function(void)
{
size_t input_length = current_length;
themis_status_t themis_status;
current_length = sizeof(shared_mem);
themis_status =
secure_comparator_proceed_compare(alice, shared_mem, input_length, shared_mem, ¤t_length);
switch (themis_status) {
case THEMIS_SCOMPARE_SEND_OUTPUT_TO_PEER:
if (0 == current_length) {
testsuite_fail_if(true, "secure_comparator_proceed_compare: invalid output length");
return TEST_STOP_ERROR;
}
return TEST_CONTINUE;
case THEMIS_SUCCESS:
if (current_length > 0) {
testsuite_fail_if(true, "secure_comparator_proceed_compare: invalid output length");
return TEST_STOP_ERROR;
}
return TEST_STOP_SUCCESS;
default:
return TEST_STOP_ERROR;
}
}
const data_t& proceed(const std::vector<uint8_t>& data)
{
if (data.empty()) {
throw themispp::exception_t(
"Secure Comparator failed to proceed comparison: data must be non-empty");
}
themis_status_t status = THEMIS_FAIL;
size_t res_data_length = 0;
status = secure_comparator_proceed_compare(comparator_, &data[0], data.size(), NULL, &res_data_length);
if (THEMIS_BUFFER_TOO_SMALL != status) {
throw themispp::exception_t("Secure Comparator failed to proceed comparison", status);
}
res_.resize(res_data_length);
status = secure_comparator_proceed_compare(comparator_, &data[0], data.size(), &res_[0], &res_data_length);
if (THEMIS_SCOMPARE_SEND_OUTPUT_TO_PEER != status && THEMIS_SUCCESS != status) {
throw themispp::exception_t("Secure Comparator failed to proceed comparison", status);
}
return res_;
}
static void corrupt_bob_step2(secure_comparator_t *bob, const void *input, size_t input_length, void *output, size_t *output_length)
{
/* Let's assume bob is malicious and uses zeroes instead of random numbers */
ge_p3 g2a;
ge_p3 g3a;
ge_p3 g2b;
ge_p3 g3b;
ge_frombytes_vartime(&g2a, (const unsigned char *)input);
ge_frombytes_vartime(&g3a, ((const unsigned char *)input) + (3 * ED25519_GE_LENGTH));
if (THEMIS_SCOMPARE_SEND_OUTPUT_TO_PEER != secure_comparator_proceed_compare(bob, input, input_length, output, output_length))
{
testsuite_fail_if(true, "secure_comparator_proceed_compare failed");
return;
}
memset(bob->rand2, 0, sizeof(bob->rand2));
memset(bob->rand3, 0, sizeof(bob->rand3));
ge_scalarmult_base(&g2b, bob->rand2);
ge_scalarmult_base(&g3b, bob->rand3);
ge_scalarmult_blinded(&(bob->g2), bob->rand2, &g2a);
ge_scalarmult_blinded(&(bob->g3), bob->rand3, &g3a);
memset(bob->rand, 0, sizeof(bob->rand));
ge_scalarmult_blinded(&(bob->P), bob->rand, &(bob->g3));
ge_double_scalarmult_vartime((ge_p2 *)&(bob->Q), bob->secret, &(bob->g2), bob->rand);
ge_p2_to_p3(&(bob->Q), (const ge_p2 *)&(bob->Q));
ge_p3_tobytes((unsigned char *)output, &g2b);
ed_sign(3, bob->rand2, ((unsigned char *)output) + ED25519_GE_LENGTH);
ge_p3_tobytes(((unsigned char *)output) + (3 * ED25519_GE_LENGTH), &g3b);
ed_sign(4, bob->rand3, ((unsigned char *)output) + (4 * ED25519_GE_LENGTH));
ge_p3_tobytes(((unsigned char *)output) + (6 * ED25519_GE_LENGTH), &(bob->P));
ge_p3_tobytes(((unsigned char *)output) + (7 * ED25519_GE_LENGTH), &(bob->Q));
ed_dbl_base_sign(5, bob->rand, bob->secret, &(bob->g2), &(bob->g3), ((unsigned char *)output) + (8 * ED25519_GE_LENGTH));
}
void secure_comparator_security_test(void)
{
const char alice_secret[] = "alice secret";
const char bob_secret[] = "bob secret";
size_t output_length = sizeof(shared_mem);
secure_comparator_t alice, bob;
if (THEMIS_SUCCESS != secure_comparator_init(&alice))
{
testsuite_fail_if(true, "secure_comparator_init failed");
return;
}
if (THEMIS_SUCCESS != secure_comparator_init(&bob))
{
testsuite_fail_if(true, "secure_comparator_init failed");
return;
}
if (THEMIS_SUCCESS != secure_comparator_append_secret(&alice, alice_secret, sizeof(alice_secret)))
{
testsuite_fail_if(true, "secure_comparator_append_secret failed");
return;
}
if (THEMIS_SUCCESS != secure_comparator_append_secret(&bob, bob_secret, sizeof(bob_secret)))
{
testsuite_fail_if(true, "secure_comparator_append_secret failed");
return;
}
current_length = sizeof(shared_mem);
if (THEMIS_SCOMPARE_SEND_OUTPUT_TO_PEER != secure_comparator_begin_compare(&alice, shared_mem, ¤t_length))
{
testsuite_fail_if(true, "secure_comparator_begin_compare failed");
return;
}
corrupt_alice_step1(&alice, shared_mem);
corrupt_bob_step2(&bob, shared_mem, current_length, shared_mem, &output_length);
current_length = output_length;
output_length = sizeof(shared_mem);
if (THEMIS_SCOMPARE_SEND_OUTPUT_TO_PEER != secure_comparator_proceed_compare(&alice, shared_mem, current_length, shared_mem, &output_length))
{
testsuite_fail_if(true, "secure_comparator_proceed_compare failed");
return;
}
current_length = output_length;
output_length = sizeof(shared_mem);
if (THEMIS_SCOMPARE_SEND_OUTPUT_TO_PEER != secure_comparator_proceed_compare(&bob, shared_mem, current_length, shared_mem, &output_length))
{
testsuite_fail_if(true, "secure_comparator_proceed_compare failed");
return;
}
current_length = output_length;
output_length = sizeof(shared_mem);
if (THEMIS_SUCCESS != secure_comparator_proceed_compare(&alice, shared_mem, current_length, shared_mem, &output_length))
{
testsuite_fail_if(true, "secure_comparator_proceed_compare failed");
return;
}
testsuite_fail_unless((THEMIS_SCOMPARE_NO_MATCH == secure_comparator_get_result(&alice)) && (THEMIS_SCOMPARE_NO_MATCH == secure_comparator_get_result(&bob)), "compare result no match");
}
