int ECDSA_verify(const char *msg, const struct affine_point *Q,
const gcry_mpi_t sig, const struct curve_params *cp)
{
gcry_mpi_t e, r, s;
struct affine_point X1, X2;
int res = 0;
r = gcry_mpi_new(0);
s = gcry_mpi_new(0);
gcry_mpi_div(s, r, sig, cp->dp.order, 0);
if (gcry_mpi_cmp_ui(s, 0) <= 0 || gcry_mpi_cmp(s, cp->dp.order) >= 0 ||
gcry_mpi_cmp_ui(r, 0) <= 0 || gcry_mpi_cmp(r, cp->dp.order) >= 0)
goto end;
gcry_mpi_scan(&e, GCRYMPI_FMT_USG, msg, 64, NULL);
gcry_mpi_mod(e, e, cp->dp.order);
gcry_mpi_invm(s, s, cp->dp.order);
gcry_mpi_mulm(e, e, s, cp->dp.order);
X1 = pointmul(&cp->dp.base, e, &cp->dp);
gcry_mpi_mulm(e, r, s, cp->dp.order);
X2 = pointmul(Q, e, &cp->dp);
point_add(&X1, &X2, &cp->dp);
gcry_mpi_release(e);
if (! point_is_zero(&X1)) {
gcry_mpi_mod(s, X1.x, cp->dp.order);
res = ! gcry_mpi_cmp(s, r);
}
point_release(&X1);
point_release(&X2);
end:
gcry_mpi_release(r);
gcry_mpi_release(s);
return res;
}
static void
mpz_tdiv_q_2exp (gcry_mpi_t q, gcry_mpi_t n, unsigned int b)
{
gcry_mpi_t u, d;
u = gcry_mpi_set_ui (NULL, 1);
d = gcry_mpi_new (0);
gcry_mpi_mul_2exp (d, u, b);
gcry_mpi_div (q, NULL, n, d, 0);
}
char *ssh_gcry_bn2dec(bignum bn) {
bignum bndup, num, ten;
char *ret;
int count, count2;
int size, rsize;
char decnum;
size = gcry_mpi_get_nbits(bn) * 3;
rsize = size / 10 + size / 1000 + 2;
ret = malloc(rsize + 1);
if (ret == NULL) {
return NULL;
}
if (!gcry_mpi_cmp_ui(bn, 0)) {
strcpy(ret, "0");
} else {
ten = bignum_new();
if (ten == NULL) {
SAFE_FREE(ret);
return NULL;
}
num = bignum_new();
if (num == NULL) {
SAFE_FREE(ret);
bignum_safe_free(ten);
return NULL;
}
for (bndup = gcry_mpi_copy(bn), bignum_set_word(ten, 10), count = rsize;
count; count--) {
gcry_mpi_div(bndup, num, bndup, ten, 0);
for (decnum = 0, count2 = gcry_mpi_get_nbits(num); count2;
decnum *= 2, decnum += (gcry_mpi_test_bit(num, count2 - 1) ? 1 : 0),
count2--)
;
ret[count - 1] = decnum + '0';
}
for (count = 0; count < rsize && ret[count] == '0'; count++)
;
for (count2 = 0; count2 < rsize - count; ++count2) {
ret[count2] = ret[count2 + count];
}
ret[count2] = 0;
bignum_safe_free(num);
bignum_safe_free(bndup);
bignum_safe_free(ten);
}
return ret;
}
/* q = a / b */
static bigint_t
wrap_gcry_mpi_div (bigint_t q, const bigint_t a, const bigint_t b)
{
if (q == NULL)
q = _gnutls_mpi_alloc_like (a);
if (q == NULL)
return NULL;
gcry_mpi_div (q, NULL, a, b, 0);
return q;
}
void serialize_mpi(char *outbuf, int outlen, enum disp_format df,
const gcry_mpi_t x)
{
switch(df) {
case DF_BIN: do {
int len = (gcry_mpi_get_nbits(x) + 7) / 8;
assert(len <= outlen);
memset(outbuf, 0, outlen - len);
gcry_mpi_print(GCRYMPI_FMT_USG, (unsigned char*)outbuf + (outlen - len),
len, NULL, x);
} while (0);
break;
case DF_COMPACT:
case DF_BASE36: do {
const char *digits = get_digits(df);
unsigned int digit_count = get_digit_count(df);
gcry_mpi_t base, Q, R;
int i;
base = gcry_mpi_set_ui(NULL, digit_count);
Q = gcry_mpi_copy(x);
R = gcry_mpi_snew(0);
for(i = outlen - 1; i >= 0; i--) {
unsigned char digit = 0;
gcry_mpi_div(Q, R, Q, base, 0);
gcry_mpi_print(GCRYMPI_FMT_USG, &digit, 1, NULL, R);
assert(digit < digit_count);
outbuf[i] = digits[digit];
}
assert(! gcry_mpi_cmp_ui(Q, 0));
gcry_mpi_release(base);
gcry_mpi_release(Q);
gcry_mpi_release(R);
} while(0);
break;
default:
assert(0);
}
}
int get_serialization_len(const gcry_mpi_t x, enum disp_format df)
{
int res;
switch(df) {
case DF_BIN:
res = (gcry_mpi_get_nbits(x) + 7) / 8;
break;
case DF_BASE36:
case DF_COMPACT:
do {
gcry_mpi_t base, Q;
base = gcry_mpi_set_ui(NULL, get_digit_count(df));
Q = gcry_mpi_copy(x);
for(res = 0; gcry_mpi_cmp_ui(Q, 0); res++)
gcry_mpi_div(Q, NULL, Q, base, 0);
gcry_mpi_release(base);
gcry_mpi_release(Q);
} while (0);
break;
default:
assert(0);
}
return res;
}
/**
* Generate a key pair with a key of size NBITS.
* @param sk where to store the key
* @param nbits the number of bits to use
* @param hc the HC to use for PRNG (modified!)
*/
static void
generate_kblock_key (KBlock_secret_key *sk, unsigned int nbits,
struct GNUNET_HashCode * hc)
{
gcry_mpi_t t1, t2;
gcry_mpi_t phi; /* helper: (p-1)(q-1) */
gcry_mpi_t g;
gcry_mpi_t f;
/* make sure that nbits is even so that we generate p, q of equal size */
if ((nbits & 1))
nbits++;
sk->e = gcry_mpi_set_ui (NULL, 257);
sk->n = gcry_mpi_new (0);
sk->p = gcry_mpi_new (0);
sk->q = gcry_mpi_new (0);
sk->d = gcry_mpi_new (0);
sk->u = gcry_mpi_new (0);
t1 = gcry_mpi_new (0);
t2 = gcry_mpi_new (0);
phi = gcry_mpi_new (0);
g = gcry_mpi_new (0);
f = gcry_mpi_new (0);
do
{
do
{
gcry_mpi_release (sk->p);
gcry_mpi_release (sk->q);
gen_prime (&sk->p, nbits / 2, hc);
gen_prime (&sk->q, nbits / 2, hc);
if (gcry_mpi_cmp (sk->p, sk->q) > 0) /* p shall be smaller than q (for calc of u) */
gcry_mpi_swap (sk->p, sk->q);
/* calculate the modulus */
gcry_mpi_mul (sk->n, sk->p, sk->q);
}
while (gcry_mpi_get_nbits (sk->n) != nbits);
/* calculate Euler totient: phi = (p-1)(q-1) */
gcry_mpi_sub_ui (t1, sk->p, 1);
gcry_mpi_sub_ui (t2, sk->q, 1);
gcry_mpi_mul (phi, t1, t2);
gcry_mpi_gcd (g, t1, t2);
gcry_mpi_div (f, NULL, phi, g, 0);
while (0 == gcry_mpi_gcd (t1, sk->e, phi))
{ /* (while gcd is not 1) */
gcry_mpi_add_ui (sk->e, sk->e, 2);
}
/* calculate the secret key d = e^1 mod phi */
}
while ((0 == gcry_mpi_invm (sk->d, sk->e, f)) ||
(0 == gcry_mpi_invm (sk->u, sk->p, sk->q)));
gcry_mpi_release (t1);
gcry_mpi_release (t2);
gcry_mpi_release (phi);
gcry_mpi_release (f);
gcry_mpi_release (g);
}
static void
gen_prime (gcry_mpi_t * ptest, unsigned int nbits, struct GNUNET_HashCode * hc)
{
/* Note: 2 is not included because it can be tested more easily by
* looking at bit 0. The last entry in this list is marked by a zero */
static const uint16_t small_prime_numbers[] = {
3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43,
47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101,
103, 107, 109, 113, 127, 131, 137, 139, 149, 151,
157, 163, 167, 173, 179, 181, 191, 193, 197, 199,
211, 223, 227, 229, 233, 239, 241, 251, 257, 263,
269, 271, 277, 281, 283, 293, 307, 311, 313, 317,
331, 337, 347, 349, 353, 359, 367, 373, 379, 383,
389, 397, 401, 409, 419, 421, 431, 433, 439, 443,
449, 457, 461, 463, 467, 479, 487, 491, 499, 503,
509, 521, 523, 541, 547, 557, 563, 569, 571, 577,
587, 593, 599, 601, 607, 613, 617, 619, 631, 641,
643, 647, 653, 659, 661, 673, 677, 683, 691, 701,
709, 719, 727, 733, 739, 743, 751, 757, 761, 769,
773, 787, 797, 809, 811, 821, 823, 827, 829, 839,
853, 857, 859, 863, 877, 881, 883, 887, 907, 911,
919, 929, 937, 941, 947, 953, 967, 971, 977, 983,
991, 997, 1009, 1013, 1019, 1021, 1031, 1033,
1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091,
1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151,
1153, 1163, 1171, 1181, 1187, 1193, 1201, 1213,
1217, 1223, 1229, 1231, 1237, 1249, 1259, 1277,
1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307,
1319, 1321, 1327, 1361, 1367, 1373, 1381, 1399,
1409, 1423, 1427, 1429, 1433, 1439, 1447, 1451,
1453, 1459, 1471, 1481, 1483, 1487, 1489, 1493,
1499, 1511, 1523, 1531, 1543, 1549, 1553, 1559,
1567, 1571, 1579, 1583, 1597, 1601, 1607, 1609,
1613, 1619, 1621, 1627, 1637, 1657, 1663, 1667,
1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733,
1741, 1747, 1753, 1759, 1777, 1783, 1787, 1789,
1801, 1811, 1823, 1831, 1847, 1861, 1867, 1871,
1873, 1877, 1879, 1889, 1901, 1907, 1913, 1931,
1933, 1949, 1951, 1973, 1979, 1987, 1993, 1997,
1999, 2003, 2011, 2017, 2027, 2029, 2039, 2053,
2063, 2069, 2081, 2083, 2087, 2089, 2099, 2111,
2113, 2129, 2131, 2137, 2141, 2143, 2153, 2161,
2179, 2203, 2207, 2213, 2221, 2237, 2239, 2243,
2251, 2267, 2269, 2273, 2281, 2287, 2293, 2297,
2309, 2311, 2333, 2339, 2341, 2347, 2351, 2357,
2371, 2377, 2381, 2383, 2389, 2393, 2399, 2411,
2417, 2423, 2437, 2441, 2447, 2459, 2467, 2473,
2477, 2503, 2521, 2531, 2539, 2543, 2549, 2551,
2557, 2579, 2591, 2593, 2609, 2617, 2621, 2633,
2647, 2657, 2659, 2663, 2671, 2677, 2683, 2687,
2689, 2693, 2699, 2707, 2711, 2713, 2719, 2729,
2731, 2741, 2749, 2753, 2767, 2777, 2789, 2791,
2797, 2801, 2803, 2819, 2833, 2837, 2843, 2851,
2857, 2861, 2879, 2887, 2897, 2903, 2909, 2917,
2927, 2939, 2953, 2957, 2963, 2969, 2971, 2999,
3001, 3011, 3019, 3023, 3037, 3041, 3049, 3061,
3067, 3079, 3083, 3089, 3109, 3119, 3121, 3137,
3163, 3167, 3169, 3181, 3187, 3191, 3203, 3209,
3217, 3221, 3229, 3251, 3253, 3257, 3259, 3271,
3299, 3301, 3307, 3313, 3319, 3323, 3329, 3331,
3343, 3347, 3359, 3361, 3371, 3373, 3389, 3391,
3407, 3413, 3433, 3449, 3457, 3461, 3463, 3467,
3469, 3491, 3499, 3511, 3517, 3527, 3529, 3533,
3539, 3541, 3547, 3557, 3559, 3571, 3581, 3583,
3593, 3607, 3613, 3617, 3623, 3631, 3637, 3643,
3659, 3671, 3673, 3677, 3691, 3697, 3701, 3709,
3719, 3727, 3733, 3739, 3761, 3767, 3769, 3779,
3793, 3797, 3803, 3821, 3823, 3833, 3847, 3851,
3853, 3863, 3877, 3881, 3889, 3907, 3911, 3917,
3919, 3923, 3929, 3931, 3943, 3947, 3967, 3989,
4001, 4003, 4007, 4013, 4019, 4021, 4027, 4049,
4051, 4057, 4073, 4079, 4091, 4093, 4099, 4111,
4127, 4129, 4133, 4139, 4153, 4157, 4159, 4177,
4201, 4211, 4217, 4219, 4229, 4231, 4241, 4243,
4253, 4259, 4261, 4271, 4273, 4283, 4289, 4297,
4327, 4337, 4339, 4349, 4357, 4363, 4373, 4391,
4397, 4409, 4421, 4423, 4441, 4447, 4451, 4457,
4463, 4481, 4483, 4493, 4507, 4513, 4517, 4519,
4523, 4547, 4549, 4561, 4567, 4583, 4591, 4597,
4603, 4621, 4637, 4639, 4643, 4649, 4651, 4657,
4663, 4673, 4679, 4691, 4703, 4721, 4723, 4729,
4733, 4751, 4759, 4783, 4787, 4789, 4793, 4799,
4801, 4813, 4817, 4831, 4861, 4871, 4877, 4889,
4903, 4909, 4919, 4931, 4933, 4937, 4943, 4951,
4957, 4967, 4969, 4973, 4987, 4993, 4999,
0
};
#define DIM(v) (sizeof(v)/sizeof((v)[0]))
static int no_of_small_prime_numbers = DIM (small_prime_numbers) - 1;
gcry_mpi_t prime, pminus1, val_2, val_3, result;
unsigned int i;
unsigned int step;
unsigned int mods[no_of_small_prime_numbers];
gcry_mpi_t tmp;
gcry_mpi_t sp;
GNUNET_assert (nbits >= 16);
/* Make nbits fit into mpz_t implementation. */
val_2 = gcry_mpi_set_ui (NULL, 2);
val_3 = gcry_mpi_set_ui (NULL, 3);
prime = gcry_mpi_snew (0);
result = gcry_mpi_new (0);
pminus1 = gcry_mpi_new (0);
*ptest = gcry_mpi_new (0);
tmp = gcry_mpi_new (0);
sp = gcry_mpi_new (0);
while (1)
{
/* generate a random number */
mpz_randomize (prime, nbits, hc);
/* Set high order bit to 1, set low order bit to 1. If we are
* generating a secret prime we are most probably doing that
* for RSA, to make sure that the modulus does have the
* requested key size we set the 2 high order bits. */
gcry_mpi_set_bit (prime, nbits - 1);
gcry_mpi_set_bit (prime, nbits - 2);
gcry_mpi_set_bit (prime, 0);
/* Calculate all remainders. */
for (i = 0; i < no_of_small_prime_numbers; i++)
{
size_t written;
gcry_mpi_set_ui (sp, small_prime_numbers[i]);
gcry_mpi_div (NULL, tmp, prime, sp, -1);
mods[i] = 0;
written = sizeof (unsigned int);
GNUNET_assert (0 ==
gcry_mpi_print (GCRYMPI_FMT_USG,
(unsigned char *) &mods[i], written,
&written, tmp));
adjust ((unsigned char *) &mods[i], written, sizeof (unsigned int));
mods[i] = ntohl (mods[i]);
}
/* Now try some primes starting with prime. */
for (step = 0; step < 20000; step += 2)
{
/* Check against all the small primes we have in mods. */
for (i = 0; i < no_of_small_prime_numbers; i++)
{
uint16_t x = small_prime_numbers[i];
while (mods[i] + step >= x)
mods[i] -= x;
if (!(mods[i] + step))
break;
}
if (i < no_of_small_prime_numbers)
continue; /* Found a multiple of an already known prime. */
gcry_mpi_add_ui (*ptest, prime, step);
if (!gcry_mpi_test_bit (*ptest, nbits - 2))
break;
/* Do a fast Fermat test now. */
gcry_mpi_sub_ui (pminus1, *ptest, 1);
gcry_mpi_powm (result, val_2, pminus1, *ptest);
if ((!gcry_mpi_cmp_ui (result, 1)) && (is_prime (*ptest, 5, hc)))
{
/* Got it. */
gcry_mpi_release (sp);
gcry_mpi_release (tmp);
gcry_mpi_release (val_2);
gcry_mpi_release (val_3);
gcry_mpi_release (result);
gcry_mpi_release (pminus1);
gcry_mpi_release (prime);
return;
}
}
}
}
/* Compute and print missing RSA parameters. */
static void
compute_missing (gcry_mpi_t rsa_p, gcry_mpi_t rsa_q, gcry_mpi_t rsa_e)
{
gcry_mpi_t rsa_n, rsa_d, rsa_pm1, rsa_qm1, rsa_u;
gcry_mpi_t phi, tmp_g, tmp_f;
rsa_n = gcry_mpi_new (0);
rsa_d = gcry_mpi_new (0);
rsa_pm1 = gcry_mpi_new (0);
rsa_qm1 = gcry_mpi_new (0);
rsa_u = gcry_mpi_new (0);
phi = gcry_mpi_new (0);
tmp_f = gcry_mpi_new (0);
tmp_g = gcry_mpi_new (0);
/* Check that p < q; if not swap p and q. */
if (openpgp_mode && gcry_mpi_cmp (rsa_p, rsa_q) > 0)
{
fprintf (stderr, PGM ": swapping p and q\n");
gcry_mpi_swap (rsa_p, rsa_q);
}
gcry_mpi_mul (rsa_n, rsa_p, rsa_q);
/* Compute the Euler totient: phi = (p-1)(q-1) */
gcry_mpi_sub_ui (rsa_pm1, rsa_p, 1);
gcry_mpi_sub_ui (rsa_qm1, rsa_q, 1);
gcry_mpi_mul (phi, rsa_pm1, rsa_qm1);
if (!gcry_mpi_gcd (tmp_g, rsa_e, phi))
die ("parameter 'e' does match 'p' and 'q'\n");
/* Compute: f = lcm(p-1,q-1) = phi / gcd(p-1,q-1) */
gcry_mpi_gcd (tmp_g, rsa_pm1, rsa_qm1);
gcry_mpi_div (tmp_f, NULL, phi, tmp_g, -1);
/* Compute the secret key: d = e^{-1} mod lcm(p-1,q-1) */
gcry_mpi_invm (rsa_d, rsa_e, tmp_f);
/* Compute the CRT helpers: d mod (p-1), d mod (q-1) */
gcry_mpi_mod (rsa_pm1, rsa_d, rsa_pm1);
gcry_mpi_mod (rsa_qm1, rsa_d, rsa_qm1);
/* Compute the CRT value: OpenPGP: u = p^{-1} mod q
Standard: iqmp = q^{-1} mod p */
if (openpgp_mode)
gcry_mpi_invm (rsa_u, rsa_p, rsa_q);
else
gcry_mpi_invm (rsa_u, rsa_q, rsa_p);
gcry_mpi_release (phi);
gcry_mpi_release (tmp_f);
gcry_mpi_release (tmp_g);
/* Print everything. */
print_mpi_line ("n", rsa_n);
print_mpi_line ("e", rsa_e);
if (openpgp_mode)
print_mpi_line ("d", rsa_d);
print_mpi_line ("p", rsa_p);
print_mpi_line ("q", rsa_q);
if (openpgp_mode)
print_mpi_line ("u", rsa_u);
else
{
print_mpi_line ("dmp1", rsa_pm1);
print_mpi_line ("dmq1", rsa_qm1);
print_mpi_line ("iqmp", rsa_u);
}
gcry_mpi_release (rsa_n);
gcry_mpi_release (rsa_d);
gcry_mpi_release (rsa_pm1);
gcry_mpi_release (rsa_qm1);
gcry_mpi_release (rsa_u);
}
/* Check the math used with Twisted Edwards curves. */
static void
twistededwards_math (void)
{
gpg_error_t err;
gcry_ctx_t ctx;
gcry_mpi_point_t G, Q;
gcry_mpi_t k;
gcry_mpi_t w, a, x, y, z, p, n, b, I;
wherestr = "twistededwards_math";
show ("checking basic Twisted Edwards math\n");
err = gcry_mpi_ec_new (&ctx, NULL, "Ed25519");
if (err)
die ("gcry_mpi_ec_new failed: %s\n", gpg_strerror (err));
k = hex2mpi
("2D3501E723239632802454EE5DDC406EFB0BDF18486A5BDE9C0390A9C2984004"
"F47252B628C953625B8DEB5DBCB8DA97AA43A1892D11FA83596F42E0D89CB1B6");
G = gcry_mpi_ec_get_point ("g", ctx, 1);
if (!G)
die ("gcry_mpi_ec_get_point(G) failed\n");
Q = gcry_mpi_point_new (0);
w = gcry_mpi_new (0);
a = gcry_mpi_new (0);
x = gcry_mpi_new (0);
y = gcry_mpi_new (0);
z = gcry_mpi_new (0);
I = gcry_mpi_new (0);
p = gcry_mpi_ec_get_mpi ("p", ctx, 1);
n = gcry_mpi_ec_get_mpi ("n", ctx, 1);
b = gcry_mpi_ec_get_mpi ("b", ctx, 1);
/* Check: 2^{p-1} mod p == 1 */
gcry_mpi_sub_ui (a, p, 1);
gcry_mpi_powm (w, GCRYMPI_CONST_TWO, a, p);
if (gcry_mpi_cmp_ui (w, 1))
fail ("failed assertion: 2^{p-1} mod p == 1\n");
/* Check: p % 4 == 1 */
gcry_mpi_mod (w, p, GCRYMPI_CONST_FOUR);
if (gcry_mpi_cmp_ui (w, 1))
fail ("failed assertion: p % 4 == 1\n");
/* Check: 2^{n-1} mod n == 1 */
gcry_mpi_sub_ui (a, n, 1);
gcry_mpi_powm (w, GCRYMPI_CONST_TWO, a, n);
if (gcry_mpi_cmp_ui (w, 1))
fail ("failed assertion: 2^{n-1} mod n == 1\n");
/* Check: b^{(p-1)/2} mod p == p-1 */
gcry_mpi_sub_ui (a, p, 1);
gcry_mpi_div (x, NULL, a, GCRYMPI_CONST_TWO, -1);
gcry_mpi_powm (w, b, x, p);
gcry_mpi_abs (w);
if (gcry_mpi_cmp (w, a))
fail ("failed assertion: b^{(p-1)/2} mod p == p-1\n");
/* I := 2^{(p-1)/4} mod p */
gcry_mpi_sub_ui (a, p, 1);
gcry_mpi_div (x, NULL, a, GCRYMPI_CONST_FOUR, -1);
gcry_mpi_powm (I, GCRYMPI_CONST_TWO, x, p);
/* Check: I^2 mod p == p-1 */
gcry_mpi_powm (w, I, GCRYMPI_CONST_TWO, p);
if (gcry_mpi_cmp (w, a))
fail ("failed assertion: I^2 mod p == p-1\n");
/* Check: G is on the curve */
if (!gcry_mpi_ec_curve_point (G, ctx))
fail ("failed assertion: G is on the curve\n");
/* Check: nG == (0,1) */
gcry_mpi_ec_mul (Q, n, G, ctx);
if (gcry_mpi_ec_get_affine (x, y, Q, ctx))
fail ("failed to get affine coordinates\n");
if (gcry_mpi_cmp_ui (x, 0) || gcry_mpi_cmp_ui (y, 1))
fail ("failed assertion: nG == (0,1)\n");
/* Now two arbitrary point operations taken from the ed25519.py
sample data. */
gcry_mpi_release (a);
a = hex2mpi
("4f71d012df3c371af3ea4dc38385ca5bb7272f90cb1b008b3ed601c76de1d496"
"e30cbf625f0a756a678d8f256d5325595cccc83466f36db18f0178eb9925edd3");
gcry_mpi_ec_mul (Q, a, G, ctx);
if (gcry_mpi_ec_get_affine (x, y, Q, ctx))
fail ("failed to get affine coordinates\n");
if (cmp_mpihex (x, ("157f7361c577aad36f67ed33e38dc7be"
"00014fecc2165ca5cee9eee19fe4d2c1"))
|| cmp_mpihex (y, ("5a69dbeb232276b38f3f5016547bb2a2"
"4025645f0b820e72b8cad4f0a909a092")))
{
fail ("sample point multiply failed:\n");
print_mpi ("r", a);
print_mpi ("Rx", x);
print_mpi ("Ry", y);
}
gcry_mpi_release (a);
a = hex2mpi
("2d3501e723239632802454ee5ddc406efb0bdf18486a5bde9c0390a9c2984004"
"f47252b628c953625b8deb5dbcb8da97aa43a1892d11fa83596f42e0d89cb1b6");
gcry_mpi_ec_mul (Q, a, G, ctx);
if (gcry_mpi_ec_get_affine (x, y, Q, ctx))
fail ("failed to get affine coordinates\n");
if (cmp_mpihex (x, ("6218e309d40065fcc338b3127f468371"
"82324bd01ce6f3cf81ab44e62959c82a"))
|| cmp_mpihex (y, ("5501492265e073d874d9e5b81e7f8784"
"8a826e80cce2869072ac60c3004356e5")))
{
fail ("sample point multiply failed:\n");
print_mpi ("r", a);
print_mpi ("Rx", x);
print_mpi ("Ry", y);
}
gcry_mpi_release (I);
gcry_mpi_release (b);
gcry_mpi_release (n);
gcry_mpi_release (p);
gcry_mpi_release (w);
gcry_mpi_release (a);
gcry_mpi_release (x);
gcry_mpi_release (y);
gcry_mpi_release (z);
gcry_mpi_point_release (Q);
gcry_mpi_point_release (G);
gcry_mpi_release (k);
gcry_ctx_release (ctx);
}
/* Check that the RSA secret key SKEY is valid. Swap parameters to
the libgcrypt standard. */
static gpg_error_t
rsa_key_check (struct rsa_secret_key_s *skey)
{
int err = 0;
gcry_mpi_t t = gcry_mpi_snew (0);
gcry_mpi_t t1 = gcry_mpi_snew (0);
gcry_mpi_t t2 = gcry_mpi_snew (0);
gcry_mpi_t phi = gcry_mpi_snew (0);
/* Check that n == p * q. */
gcry_mpi_mul (t, skey->p, skey->q);
if (gcry_mpi_cmp( t, skey->n) )
{
log_error ("RSA oops: n != p * q\n");
err++;
}
/* Check that p is less than q. */
if (gcry_mpi_cmp (skey->p, skey->q) > 0)
{
gcry_mpi_t tmp;
log_info ("swapping secret primes\n");
tmp = gcry_mpi_copy (skey->p);
gcry_mpi_set (skey->p, skey->q);
gcry_mpi_set (skey->q, tmp);
gcry_mpi_release (tmp);
/* Recompute u. */
gcry_mpi_invm (skey->u, skey->p, skey->q);
}
/* Check that e divides neither p-1 nor q-1. */
gcry_mpi_sub_ui (t, skey->p, 1 );
gcry_mpi_div (NULL, t, t, skey->e, 0);
if (!gcry_mpi_cmp_ui( t, 0) )
{
log_error ("RSA oops: e divides p-1\n");
err++;
}
gcry_mpi_sub_ui (t, skey->q, 1);
gcry_mpi_div (NULL, t, t, skey->e, 0);
if (!gcry_mpi_cmp_ui( t, 0))
{
log_info ("RSA oops: e divides q-1\n" );
err++;
}
/* Check that d is correct. */
gcry_mpi_sub_ui (t1, skey->p, 1);
gcry_mpi_sub_ui (t2, skey->q, 1);
gcry_mpi_mul (phi, t1, t2);
gcry_mpi_invm (t, skey->e, phi);
if (gcry_mpi_cmp (t, skey->d))
{
/* No: try universal exponent. */
gcry_mpi_gcd (t, t1, t2);
gcry_mpi_div (t, NULL, phi, t, 0);
gcry_mpi_invm (t, skey->e, t);
if (gcry_mpi_cmp (t, skey->d))
{
log_error ("RSA oops: bad secret exponent\n");
err++;
}
}
/* Check for correctness of u. */
gcry_mpi_invm (t, skey->p, skey->q);
if (gcry_mpi_cmp (t, skey->u))
{
log_info ("RSA oops: bad u parameter\n");
err++;
}
if (err)
log_info ("RSA secret key check failed\n");
gcry_mpi_release (t);
gcry_mpi_release (t1);
gcry_mpi_release (t2);
gcry_mpi_release (phi);
return err? gpg_error (GPG_ERR_BAD_SECKEY):0;
}
