/* To generate a DH key either q must be set in the params or
* level should be set to the number of required bits.
*/
static int
wrap_nettle_pk_generate_keys(gnutls_pk_algorithm_t algo,
unsigned int level /*bits */ ,
gnutls_pk_params_st * params)
{
int ret;
unsigned int i;
switch (algo) {
case GNUTLS_PK_DSA:
#ifdef ENABLE_FIPS140
{
struct dsa_public_key pub;
struct dsa_private_key priv;
if (params->params[DSA_Q] == NULL)
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
_dsa_params_to_pubkey(params, &pub);
dsa_private_key_init(&priv);
mpz_init(pub.y);
ret =
dsa_generate_dss_keypair(&pub, &priv,
NULL, rnd_func,
NULL, NULL);
if (ret != 1) {
gnutls_assert();
ret = GNUTLS_E_PK_GENERATION_ERROR;
goto dsa_fail;
}
ret = _gnutls_mpi_init_multi(¶ms->params[DSA_Y], ¶ms->params[DSA_X], NULL);
if (ret < 0) {
gnutls_assert();
goto dsa_fail;
}
mpz_set(TOMPZ(params->params[DSA_Y]), pub.y);
mpz_set(TOMPZ(params->params[DSA_X]), priv.x);
params->params_nr += 2;
dsa_fail:
dsa_private_key_clear(&priv);
mpz_clear(pub.y);
if (ret < 0)
goto fail;
break;
}
#endif
case GNUTLS_PK_DH:
{
struct dsa_public_key pub;
mpz_t r;
mpz_t x, y;
int max_tries;
unsigned have_q = 0;
if (algo != params->algo)
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
_dsa_params_to_pubkey(params, &pub);
if (params->params[DSA_Q] != NULL)
have_q = 1;
/* This check is for the case !ENABLE_FIPS140 */
if (algo == GNUTLS_PK_DSA && have_q == 0)
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
mpz_init(r);
mpz_init(x);
mpz_init(y);
max_tries = 3;
do {
if (have_q) {
mpz_set(r, pub.q);
mpz_sub_ui(r, r, 2);
nettle_mpz_random(x, NULL, rnd_func, r);
mpz_add_ui(x, x, 1);
} else {
unsigned size = mpz_sizeinbase(pub.p, 2);
if (level == 0)
level = MIN(size, DH_EXPONENT_SIZE(size));
nettle_mpz_random_size(x, NULL, rnd_func, level);
if (level >= size)
mpz_mod(x, x, pub.p);
}
mpz_powm(y, pub.g, x, pub.p);
max_tries--;
if (max_tries <= 0) {
gnutls_assert();
ret = GNUTLS_E_RANDOM_FAILED;
goto dh_fail;
}
} while(mpz_cmp_ui(y, 1) == 0);
ret = _gnutls_mpi_init_multi(¶ms->params[DSA_Y], ¶ms->params[DSA_X], NULL);
if (ret < 0) {
gnutls_assert();
goto dh_fail;
}
mpz_set(TOMPZ(params->params[DSA_Y]), y);
mpz_set(TOMPZ(params->params[DSA_X]), x);
params->params_nr += 2;
ret = 0;
dh_fail:
mpz_clear(r);
mpz_clear(x);
mpz_clear(y);
if (ret < 0)
goto fail;
break;
}
case GNUTLS_PK_RSA:
{
struct rsa_public_key pub;
struct rsa_private_key priv;
rsa_public_key_init(&pub);
rsa_private_key_init(&priv);
mpz_set_ui(pub.e, 65537);
#ifdef ENABLE_FIPS140
ret =
rsa_generate_fips186_4_keypair(&pub, &priv, NULL,
rnd_func, NULL, NULL,
level);
#else
ret =
rsa_generate_keypair(&pub, &priv, NULL,
rnd_func, NULL, NULL,
level, 0);
#endif
if (ret != 1) {
gnutls_assert();
ret = GNUTLS_E_PK_GENERATION_ERROR;
goto rsa_fail;
}
params->params_nr = 0;
for (i = 0; i < RSA_PRIVATE_PARAMS; i++) {
ret = _gnutls_mpi_init(¶ms->params[i]);
if (ret < 0) {
gnutls_assert();
goto rsa_fail;
}
params->params_nr++;
}
mpz_set(TOMPZ(params->params[0]), pub.n);
mpz_set(TOMPZ(params->params[1]), pub.e);
mpz_set(TOMPZ(params->params[2]), priv.d);
mpz_set(TOMPZ(params->params[3]), priv.p);
mpz_set(TOMPZ(params->params[4]), priv.q);
mpz_set(TOMPZ(params->params[5]), priv.c);
mpz_set(TOMPZ(params->params[6]), priv.a);
mpz_set(TOMPZ(params->params[7]), priv.b);
ret = 0;
rsa_fail:
rsa_private_key_clear(&priv);
rsa_public_key_clear(&pub);
if (ret < 0)
goto fail;
break;
}
case GNUTLS_PK_EC:
{
struct ecc_scalar key;
struct ecc_point pub;
const struct ecc_curve *curve;
curve = get_supported_curve(level);
if (curve == NULL)
return
gnutls_assert_val
(GNUTLS_E_ECC_UNSUPPORTED_CURVE);
ecc_scalar_init(&key, curve);
ecc_point_init(&pub, curve);
ecdsa_generate_keypair(&pub, &key, NULL, rnd_func);
ret = _gnutls_mpi_init_multi(¶ms->params[ECC_X], ¶ms->params[ECC_Y],
¶ms->params[ECC_K], NULL);
if (ret < 0) {
gnutls_assert();
goto ecc_fail;
}
params->flags = level;
params->params_nr = ECC_PRIVATE_PARAMS;
ecc_point_get(&pub, TOMPZ(params->params[ECC_X]),
TOMPZ(params->params[ECC_Y]));
ecc_scalar_get(&key, TOMPZ(params->params[ECC_K]));
ret = 0;
ecc_fail:
ecc_point_clear(&pub);
ecc_scalar_clear(&key);
if (ret < 0)
goto fail;
break;
}
default:
gnutls_assert();
return GNUTLS_E_INVALID_REQUEST;
}
FAIL_IF_LIB_ERROR;
return 0;
fail:
for (i = 0; i < params->params_nr; i++) {
_gnutls_mpi_release(¶ms->params[i]);
}
params->params_nr = 0;
FAIL_IF_LIB_ERROR;
return ret;
}
int
rsa_generate_keypair(struct rsa_public_key *pub,
struct rsa_private_key *key,
void *random_ctx, nettle_random_func *random,
void *progress_ctx, nettle_progress_func *progress,
unsigned n_size,
unsigned e_size)
{
mpz_t p1;
mpz_t q1;
mpz_t phi;
mpz_t tmp;
if (e_size)
{
/* We should choose e randomly. Is the size reasonable? */
if ((e_size < 16) || (e_size >= n_size) )
return 0;
}
else
{
/* We have a fixed e. Check that it makes sense */
/* It must be odd */
if (!mpz_tstbit(pub->e, 0))
return 0;
/* And 3 or larger */
if (mpz_cmp_ui(pub->e, 3) < 0)
return 0;
/* And size less than n */
if (mpz_sizeinbase(pub->e, 2) >= n_size)
return 0;
}
if (n_size < RSA_MINIMUM_N_BITS)
return 0;
mpz_init(p1); mpz_init(q1); mpz_init(phi); mpz_init(tmp);
/* Generate primes */
for (;;)
{
/* Generate p, such that gcd(p-1, e) = 1 */
for (;;)
{
nettle_random_prime(key->p, (n_size+1)/2, 1,
random_ctx, random,
progress_ctx, progress);
mpz_sub_ui(p1, key->p, 1);
/* If e was given, we must chose p such that p-1 has no factors in
* common with e. */
if (e_size)
break;
mpz_gcd(tmp, pub->e, p1);
if (mpz_cmp_ui(tmp, 1) == 0)
break;
else if (progress) progress(progress_ctx, 'c');
}
if (progress)
progress(progress_ctx, '\n');
/* Generate q, such that gcd(q-1, e) = 1 */
for (;;)
{
nettle_random_prime(key->q, n_size/2, 1,
random_ctx, random,
progress_ctx, progress);
/* Very unlikely. */
if (mpz_cmp (key->q, key->p) == 0)
continue;
mpz_sub_ui(q1, key->q, 1);
/* If e was given, we must chose q such that q-1 has no factors in
* common with e. */
if (e_size)
break;
mpz_gcd(tmp, pub->e, q1);
if (mpz_cmp_ui(tmp, 1) == 0)
break;
else if (progress) progress(progress_ctx, 'c');
}
/* Now we have the primes. Is the product of the right size? */
mpz_mul(pub->n, key->p, key->q);
assert (mpz_sizeinbase(pub->n, 2) == n_size);
if (progress)
progress(progress_ctx, '\n');
/* c = q^{-1} (mod p) */
if (mpz_invert(key->c, key->q, key->p))
/* This should succeed everytime. But if it doesn't,
* we try again. */
break;
else if (progress) progress(progress_ctx, '?');
}
mpz_mul(phi, p1, q1);
/* If we didn't have a given e, generate one now. */
if (e_size)
{
int retried = 0;
for (;;)
{
nettle_mpz_random_size(pub->e,
random_ctx, random,
e_size);
/* Make sure it's odd and that the most significant bit is
* set */
mpz_setbit(pub->e, 0);
mpz_setbit(pub->e, e_size - 1);
/* Needs gmp-3, or inverse might be negative. */
if (mpz_invert(key->d, pub->e, phi))
break;
if (progress) progress(progress_ctx, 'e');
retried = 1;
}
if (retried && progress)
progress(progress_ctx, '\n');
}
else
{
/* Must always succeed, as we already that e
* doesn't have any common factor with p-1 or q-1. */
int res = mpz_invert(key->d, pub->e, phi);
assert(res);
}
/* Done! Almost, we must compute the auxillary private values. */
/* a = d % (p-1) */
mpz_fdiv_r(key->a, key->d, p1);
/* b = d % (q-1) */
mpz_fdiv_r(key->b, key->d, q1);
/* c was computed earlier */
pub->size = key->size = (n_size + 7) / 8;
assert(pub->size >= RSA_MINIMUM_N_OCTETS);
mpz_clear(p1); mpz_clear(q1); mpz_clear(phi); mpz_clear(tmp);
return 1;
}
static void
dsa_nist_gen(mpz_t p, mpz_t q,
void *random_ctx, nettle_random_func random,
void *progress_ctx, nettle_progress_func progress,
unsigned L)
{
unsigned n;
unsigned b;
mpz_t s;
mpz_t t;
mpz_t c;
/* For NIS keysizes, we should have L = 512 + 64 * l */
n = (L-1) / 160; b = (L-1) % 160;
mpz_init(s);
mpz_init(t);
mpz_init(c);
for (;;)
{
{ /* Generate q */
uint8_t h1[SHA1_DIGEST_SIZE];
uint8_t h2[SHA1_DIGEST_SIZE];
if (progress)
progress(progress_ctx, '.');
nettle_mpz_random_size(s, random_ctx, random, SEED_BITS);
hash(s, h1);
mpz_set(t, s);
mpz_add_ui(t, t, 1);
hash(t, h2);
memxor(h1, h2, SHA1_DIGEST_SIZE);
h1[0] |= 0x80;
h1[SHA1_DIGEST_SIZE - 1] |= 1;
nettle_mpz_set_str_256_u(q, SHA1_DIGEST_SIZE, h1);
/* The spec says that we should use 18 iterations of
* miller-rabin. For performance, we want to do some trial
* divisions first. The curent version of mpz_probab_prime_p
* does exactly that. */
if (!mpz_probab_prime_p(q, 18))
/* Try new seed. */
continue;
}
/* q is a prime, with overwhelming probability. */
if (progress)
progress(progress_ctx, '\n');
{
/* Official maximum key size: L = 1024 => n = 6 */
TMP_DECL(buffer, uint8_t, (6 + 1) * SHA1_DIGEST_SIZE);
unsigned size = (n+1) * SHA1_DIGEST_SIZE;
unsigned i, j;
TMP_ALLOC(buffer, size);
for (i = 0, j = 2; i<4096; i++, j+= n+1)
{
unsigned k;
if (progress)
progress(progress_ctx, ',');
for (k = 0; k<=n ; k++)
{
mpz_set(t, s);
mpz_add_ui(t, t, j + k);
hash(t, buffer + ( (n-k) * SHA1_DIGEST_SIZE));
}
nettle_mpz_set_str_256_u(p, size, buffer);
mpz_fdiv_r_2exp(p, p, L);
mpz_setbit(p, L-1);
mpz_set(t, q);
mpz_mul_2exp(t, t, 1);
mpz_fdiv_r(c, p, t);
mpz_sub_ui(c, c, 1);
mpz_sub(p, p, c);
if (mpz_probab_prime_p(p, 5))
{
/* Done! */
if (progress)
progress(progress_ctx, '\n');
mpz_clear(s);
mpz_clear(t);
mpz_clear(c);
return;
}
}
if (progress)
progress(progress_ctx, '+');
}
}
}
