int ec_key_simple_generate_key(EC_KEY *eckey)
{
int ok = 0;
BN_CTX *ctx = NULL;
BIGNUM *priv_key = NULL;
const BIGNUM *order = NULL;
EC_POINT *pub_key = NULL;
if ((ctx = BN_CTX_new()) == NULL)
goto err;
if (eckey->priv_key == NULL) {
priv_key = BN_new();
if (priv_key == NULL)
goto err;
} else
priv_key = eckey->priv_key;
order = EC_GROUP_get0_order(eckey->group);
if (order == NULL)
goto err;
do
if (!BN_priv_rand_range(priv_key, order))
goto err;
while (BN_is_zero(priv_key)) ;
if (eckey->pub_key == NULL) {
pub_key = EC_POINT_new(eckey->group);
if (pub_key == NULL)
goto err;
} else
pub_key = eckey->pub_key;
if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
goto err;
eckey->priv_key = priv_key;
eckey->pub_key = pub_key;
ok = 1;
err:
if (eckey->pub_key == NULL)
EC_POINT_free(pub_key);
if (eckey->priv_key != priv_key)
BN_free(priv_key);
BN_CTX_free(ctx);
return ok;
}
/*-
* Apply randomization of EC point projective coordinates:
*
* (X, Y ,Z ) = (lambda^2*X, lambda^3*Y, lambda*Z)
* lambda = [1,group->field)
*
*/
int ec_GFp_simple_blind_coordinates(const EC_GROUP *group, EC_POINT *p,
BN_CTX *ctx)
{
int ret = 0;
BIGNUM *lambda = NULL;
BIGNUM *temp = NULL;
BN_CTX_start(ctx);
lambda = BN_CTX_get(ctx);
temp = BN_CTX_get(ctx);
if (temp == NULL) {
ECerr(EC_F_EC_GFP_SIMPLE_BLIND_COORDINATES, ERR_R_MALLOC_FAILURE);
goto err;
}
/* make sure lambda is not zero */
do {
if (!BN_priv_rand_range(lambda, group->field)) {
ECerr(EC_F_EC_GFP_SIMPLE_BLIND_COORDINATES, ERR_R_BN_LIB);
goto err;
}
} while (BN_is_zero(lambda));
/* if field_encode defined convert between representations */
if (group->meth->field_encode != NULL
&& !group->meth->field_encode(group, lambda, lambda, ctx))
goto err;
if (!group->meth->field_mul(group, p->Z, p->Z, lambda, ctx))
goto err;
if (!group->meth->field_sqr(group, temp, lambda, ctx))
goto err;
if (!group->meth->field_mul(group, p->X, p->X, temp, ctx))
goto err;
if (!group->meth->field_mul(group, temp, temp, lambda, ctx))
goto err;
if (!group->meth->field_mul(group, p->Y, p->Y, temp, ctx))
goto err;
p->Z_is_one = 0;
ret = 1;
err:
BN_CTX_end(ctx);
return ret;
}
int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed,
int do_trial_division, BN_GENCB *cb)
{
int i, j, ret = -1;
int k;
BN_CTX *ctx = NULL;
BIGNUM *A1, *A1_odd, *check; /* taken from ctx */
BN_MONT_CTX *mont = NULL;
if (BN_cmp(a, BN_value_one()) <= 0)
return 0;
if (checks == BN_prime_checks)
checks = BN_prime_checks_for_size(BN_num_bits(a));
/* first look for small factors */
if (!BN_is_odd(a))
/* a is even => a is prime if and only if a == 2 */
return BN_is_word(a, 2);
if (do_trial_division) {
for (i = 1; i < NUMPRIMES; i++) {
BN_ULONG mod = BN_mod_word(a, primes[i]);
if (mod == (BN_ULONG)-1)
goto err;
if (mod == 0)
return BN_is_word(a, primes[i]);
}
if (!BN_GENCB_call(cb, 1, -1))
goto err;
}
if (ctx_passed != NULL)
ctx = ctx_passed;
else if ((ctx = BN_CTX_new()) == NULL)
goto err;
BN_CTX_start(ctx);
A1 = BN_CTX_get(ctx);
A1_odd = BN_CTX_get(ctx);
check = BN_CTX_get(ctx);
if (check == NULL)
goto err;
/* compute A1 := a - 1 */
if (!BN_copy(A1, a))
goto err;
if (!BN_sub_word(A1, 1))
goto err;
if (BN_is_zero(A1)) {
ret = 0;
goto err;
}
/* write A1 as A1_odd * 2^k */
k = 1;
while (!BN_is_bit_set(A1, k))
k++;
if (!BN_rshift(A1_odd, A1, k))
goto err;
/* Montgomery setup for computations mod a */
mont = BN_MONT_CTX_new();
if (mont == NULL)
goto err;
if (!BN_MONT_CTX_set(mont, a, ctx))
goto err;
for (i = 0; i < checks; i++) {
if (!BN_priv_rand_range(check, A1))
goto err;
if (!BN_add_word(check, 1))
goto err;
/* now 1 <= check < a */
j = witness(check, a, A1, A1_odd, k, ctx, mont);
if (j == -1)
goto err;
if (j) {
ret = 0;
goto err;
}
if (!BN_GENCB_call(cb, 1, i))
goto err;
}
ret = 1;
err:
if (ctx != NULL) {
BN_CTX_end(ctx);
if (ctx_passed == NULL)
BN_CTX_free(ctx);
}
BN_MONT_CTX_free(mont);
return ret;
}
/*
* Refer to FIPS 186-4 C.3.2 Enhanced Miller-Rabin Probabilistic Primality Test.
* OR C.3.1 Miller-Rabin Probabilistic Primality Test (if enhanced is zero).
* The Step numbers listed in the code refer to the enhanced case.
*
* if enhanced is set, then status returns one of the following:
* BN_PRIMETEST_PROBABLY_PRIME
* BN_PRIMETEST_COMPOSITE_WITH_FACTOR
* BN_PRIMETEST_COMPOSITE_NOT_POWER_OF_PRIME
* if enhanced is zero, then status returns either
* BN_PRIMETEST_PROBABLY_PRIME or
* BN_PRIMETEST_COMPOSITE
*
* returns 0 if there was an error, otherwise it returns 1.
*/
int bn_miller_rabin_is_prime(const BIGNUM *w, int iterations, BN_CTX *ctx,
BN_GENCB *cb, int enhanced, int *status)
{
int i, j, a, ret = 0;
BIGNUM *g, *w1, *w3, *x, *m, *z, *b;
BN_MONT_CTX *mont = NULL;
/* w must be odd */
if (!BN_is_odd(w))
return 0;
BN_CTX_start(ctx);
g = BN_CTX_get(ctx);
w1 = BN_CTX_get(ctx);
w3 = BN_CTX_get(ctx);
x = BN_CTX_get(ctx);
m = BN_CTX_get(ctx);
z = BN_CTX_get(ctx);
b = BN_CTX_get(ctx);
if (!(b != NULL
/* w1 := w - 1 */
&& BN_copy(w1, w)
&& BN_sub_word(w1, 1)
/* w3 := w - 3 */
&& BN_copy(w3, w)
&& BN_sub_word(w3, 3)))
goto err;
/* check w is larger than 3, otherwise the random b will be too small */
if (BN_is_zero(w3) || BN_is_negative(w3))
goto err;
/* (Step 1) Calculate largest integer 'a' such that 2^a divides w-1 */
a = 1;
while (!BN_is_bit_set(w1, a))
a++;
/* (Step 2) m = (w-1) / 2^a */
if (!BN_rshift(m, w1, a))
goto err;
/* Montgomery setup for computations mod a */
mont = BN_MONT_CTX_new();
if (mont == NULL || !BN_MONT_CTX_set(mont, w, ctx))
goto err;
if (iterations == BN_prime_checks)
iterations = BN_prime_checks_for_size(BN_num_bits(w));
/* (Step 4) */
for (i = 0; i < iterations; ++i) {
/* (Step 4.1) obtain a Random string of bits b where 1 < b < w-1 */
if (!BN_priv_rand_range(b, w3) || !BN_add_word(b, 2)) /* 1 < b < w-1 */
goto err;
if (enhanced) {
/* (Step 4.3) */
if (!BN_gcd(g, b, w, ctx))
goto err;
/* (Step 4.4) */
if (!BN_is_one(g)) {
*status = BN_PRIMETEST_COMPOSITE_WITH_FACTOR;
ret = 1;
goto err;
}
}
/* (Step 4.5) z = b^m mod w */
if (!BN_mod_exp_mont(z, b, m, w, ctx, mont))
goto err;
/* (Step 4.6) if (z = 1 or z = w-1) */
if (BN_is_one(z) || BN_cmp(z, w1) == 0)
goto outer_loop;
/* (Step 4.7) for j = 1 to a-1 */
for (j = 1; j < a ; ++j) {
/* (Step 4.7.1 - 4.7.2) x = z. z = x^2 mod w */
if (!BN_copy(x, z) || !BN_mod_mul(z, x, x, w, ctx))
goto err;
/* (Step 4.7.3) */
if (BN_cmp(z, w1) == 0)
goto outer_loop;
/* (Step 4.7.4) */
if (BN_is_one(z))
goto composite;
}
/* At this point z = b^((w-1)/2) mod w */
/* (Steps 4.8 - 4.9) x = z, z = x^2 mod w */
if (!BN_copy(x, z) || !BN_mod_mul(z, x, x, w, ctx))
goto err;
/* (Step 4.10) */
if (BN_is_one(z))
goto composite;
/* (Step 4.11) x = b^(w-1) mod w */
if (!BN_copy(x, z))
goto err;
composite:
if (enhanced) {
/* (Step 4.1.2) g = GCD(x-1, w) */
if (!BN_sub_word(x, 1) || !BN_gcd(g, x, w, ctx))
goto err;
/* (Steps 4.1.3 - 4.1.4) */
if (BN_is_one(g))
*status = BN_PRIMETEST_COMPOSITE_NOT_POWER_OF_PRIME;
else
*status = BN_PRIMETEST_COMPOSITE_WITH_FACTOR;
} else {
*status = BN_PRIMETEST_COMPOSITE;
}
ret = 1;
goto err;
outer_loop: ;
/* (Step 4.1.5) */
if (!BN_GENCB_call(cb, 1, i))
goto err;
}
/* (Step 5) */
*status = BN_PRIMETEST_PROBABLY_PRIME;
ret = 1;
err:
BN_clear(g);
BN_clear(w1);
BN_clear(w3);
BN_clear(x);
BN_clear(m);
BN_clear(z);
BN_clear(b);
BN_CTX_end(ctx);
BN_MONT_CTX_free(mont);
return ret;
}
static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in,
BIGNUM **kinvp, BIGNUM **rp,
const unsigned char *dgst, int dlen)
{
BN_CTX *ctx = NULL;
BIGNUM *k = NULL, *r = NULL, *X = NULL;
const BIGNUM *order;
EC_POINT *tmp_point = NULL;
const EC_GROUP *group;
int ret = 0;
int order_bits;
if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
if (!EC_KEY_can_sign(eckey)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
return 0;
}
if (ctx_in == NULL) {
if ((ctx = BN_CTX_new()) == NULL) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
return 0;
}
} else
ctx = ctx_in;
k = BN_new(); /* this value is later returned in *kinvp */
r = BN_new(); /* this value is later returned in *rp */
X = BN_new();
if (k == NULL || r == NULL || X == NULL) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
goto err;
}
if ((tmp_point = EC_POINT_new(group)) == NULL) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
goto err;
}
order = EC_GROUP_get0_order(group);
if (order == NULL) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
goto err;
}
/* Preallocate space */
order_bits = BN_num_bits(order);
if (!BN_set_bit(k, order_bits)
|| !BN_set_bit(r, order_bits)
|| !BN_set_bit(X, order_bits))
goto err;
do {
/* get random k */
do
if (dgst != NULL) {
if (!BN_generate_dsa_nonce
(k, order, EC_KEY_get0_private_key(eckey), dgst, dlen,
ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP,
EC_R_RANDOM_NUMBER_GENERATION_FAILED);
goto err;
}
} else {
if (!BN_priv_rand_range(k, order)) {
ECerr(EC_F_ECDSA_SIGN_SETUP,
EC_R_RANDOM_NUMBER_GENERATION_FAILED);
goto err;
}
}
while (BN_is_zero(k));
/* compute r the x-coordinate of generator * k */
if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
goto err;
}
if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) ==
NID_X9_62_prime_field) {
if (!EC_POINT_get_affine_coordinates_GFp
(group, tmp_point, X, NULL, ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
goto err;
}
}
#ifndef OPENSSL_NO_EC2M
else { /* NID_X9_62_characteristic_two_field */
if (!EC_POINT_get_affine_coordinates_GF2m(group,
tmp_point, X, NULL,
ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
goto err;
}
}
#endif
if (!BN_nnmod(r, X, order, ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
goto err;
}
}
while (BN_is_zero(r));
/* Check if optimized inverse is implemented */
if (EC_GROUP_do_inverse_ord(group, k, k, ctx) == 0) {
/* compute the inverse of k */
if (group->mont_data != NULL) {
/*
* We want inverse in constant time, therefore we utilize the fact
* order must be prime and use Fermats Little Theorem instead.
*/
if (!BN_set_word(X, 2)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
goto err;
}
if (!BN_mod_sub(X, order, X, order, ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
goto err;
}
BN_set_flags(X, BN_FLG_CONSTTIME);
if (!BN_mod_exp_mont_consttime(k, k, X, order, ctx,
group->mont_data)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
goto err;
}
} else {
if (!BN_mod_inverse(k, k, order, ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
goto err;
}
}
}
/* clear old values if necessary */
BN_clear_free(*rp);
BN_clear_free(*kinvp);
/* save the pre-computed values */
*rp = r;
*kinvp = k;
ret = 1;
err:
if (!ret) {
BN_clear_free(k);
BN_clear_free(r);
}
if (ctx != ctx_in)
BN_CTX_free(ctx);
EC_POINT_free(tmp_point);
BN_clear_free(X);
return ret;
}
