END_TEST
/* Random unit test for ec_mul and ec_add */
START_TEST (test_random_addmul)
{
FF_NUM a, b, c;
EC_POINT P, Q, R, T1, T2;
for (int passes = 0; passes < 10; ++passes)
{
ff_rand (&a, &ec_n);
ff_rand (&b, &ec_n);
ff_add (&c, &a, &b, &ec_n);
ec_mul (&P, &a, &ec_G);
ec_mul (&Q, &b, &ec_G);
ec_mul (&R, &c, &ec_G);
ec_add (&T1, &P, &Q);
ec_add (&T2, &Q, &P);
if (ff_compare (&(T1.x), &(R.x)) != 0 || ff_compare (&(T1.y), &(R.y)) != 0 || ff_compare (&(T2.x), &(R.x)) != 0 || ff_compare (&(T2.y), &(R.y)) != 0)
{
printf ("a: ");
print_ff (&a);
printf ("\nb: ");
print_ff (&b);
printf ("\nc: ");
print_ff (&c);
printf ("\nP: 04");
print_ff (&(P.x));
print_ff (&(P.y));
printf ("\nQ: 04");
print_ff (&(Q.x));
print_ff (&(Q.y));
printf ("\nR: 04");
print_ff (&(R.x));
print_ff (&(R.y));
printf ("\nT1: 04");
print_ff (&(T1.x));
print_ff (&(T1.y));
printf ("\nT2: 04");
print_ff (&(T2.x));
print_ff (&(T2.y));
printf ("\n");
return "If c = a + b is true then the following should be true: aG + bG == cG and bG + aG == cG.";
}
}
}
int cp_ecdh_key(uint8_t *key, int key_len, bn_t d, ec_t q) {
ec_t p;
bn_t x, h;
int l, result = STS_OK;
uint8_t _x[FC_BYTES];
ec_null(p);
bn_null(x);
bn_null(h);
TRY {
ec_new(p);
bn_new(x);
bn_new(h);
ec_curve_get_cof(h);
if (bn_bits(h) < BN_DIGIT) {
ec_mul_dig(p, q, h->dp[0]);
} else {
ec_mul(p, q, h);
}
ec_mul(p, p, d);
if (ec_is_infty(p)) {
result = STS_ERR;
}
ec_get_x(x, p);
l = bn_size_bin(x);
bn_write_bin(_x, l, x);
md_kdf2(key, key_len, _x, l);
}
CATCH_ANY {
THROW(ERR_CAUGHT);
}
FINALLY {
ec_free(p);
bn_free(x);
bn_free(h);
}
return result;
}
END_TEST
/* Test corner cases */
START_TEST (test_sign_corner)
{
EC_POINT pubkey;
FF_NUM privkey = {0x00000001,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000};
const FF_NUM hash = {0};
FF_NUM r, s;
const FF_NUM hash2 = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
ec_mul (&pubkey, &privkey, &ec_G);
ec_sign (&r, &s, &hash, &privkey);
mu_assert (ec_verify (&hash, &pubkey, &r, &s), "ec_sign should create a signature that can be verified with ec_verify when the private key is 1.");
ec_create_key (&privkey, &pubkey);
ec_sign (&r, &s, &hash, &privkey);
mu_assert (ec_verify (&hash, &pubkey, &r, &s), "ec_sign should create a signature that can be verified with ec_verify when the hash is 0.");
ec_sign (&r, &s, &hash2, &privkey);
mu_assert (ec_verify (&hash2, &pubkey, &r, &s), "ec_sign should create a signature that can be verified with ec_verify when the hash is 2^256-1.");
}
