int DH_compute_key(unsigned char *out, const BIGNUM *peers_key, DH *dh) {
BN_CTX *ctx = NULL;
BIGNUM *shared_key;
int ret = -1;
int check_result;
if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) {
OPENSSL_PUT_ERROR(DH, DH_R_MODULUS_TOO_LARGE);
goto err;
}
ctx = BN_CTX_new();
if (ctx == NULL) {
goto err;
}
BN_CTX_start(ctx);
shared_key = BN_CTX_get(ctx);
if (shared_key == NULL) {
goto err;
}
if (dh->priv_key == NULL) {
OPENSSL_PUT_ERROR(DH, DH_R_NO_PRIVATE_VALUE);
goto err;
}
if (!BN_MONT_CTX_set_locked(&dh->method_mont_p, &dh->method_mont_p_lock,
dh->p, ctx)) {
goto err;
}
if (!DH_check_pub_key(dh, peers_key, &check_result) || check_result) {
OPENSSL_PUT_ERROR(DH, DH_R_INVALID_PUBKEY);
goto err;
}
if (!BN_mod_exp_mont_consttime(shared_key, peers_key, dh->priv_key, dh->p,
ctx, dh->method_mont_p)) {
OPENSSL_PUT_ERROR(DH, ERR_R_BN_LIB);
goto err;
}
ret = BN_bn2bin(shared_key, out);
err:
if (ctx != NULL) {
BN_CTX_end(ctx);
BN_CTX_free(ctx);
}
return ret;
}
static int mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) {
assert(ctx != NULL);
assert(rsa->n != NULL);
assert(rsa->e != NULL);
assert(rsa->d != NULL);
assert(rsa->p != NULL);
assert(rsa->q != NULL);
assert(rsa->dmp1 != NULL);
assert(rsa->dmq1 != NULL);
assert(rsa->iqmp != NULL);
BIGNUM *r1, *m1, *vrfy;
BIGNUM local_dmp1, local_dmq1, local_c, local_r1;
BIGNUM *dmp1, *dmq1, *c, *pr1;
int ret = 0;
size_t i, num_additional_primes = 0;
if (rsa->additional_primes != NULL) {
num_additional_primes = sk_RSA_additional_prime_num(rsa->additional_primes);
}
BN_CTX_start(ctx);
r1 = BN_CTX_get(ctx);
m1 = BN_CTX_get(ctx);
vrfy = BN_CTX_get(ctx);
if (r1 == NULL ||
m1 == NULL ||
vrfy == NULL) {
goto err;
}
{
BIGNUM local_p, local_q;
BIGNUM *p = NULL, *q = NULL;
/* Make sure BN_mod in Montgomery initialization uses BN_FLG_CONSTTIME. */
BN_init(&local_p);
p = &local_p;
BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
BN_init(&local_q);
q = &local_q;
BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
if (!BN_MONT_CTX_set_locked(&rsa->mont_p, &rsa->lock, p, ctx) ||
!BN_MONT_CTX_set_locked(&rsa->mont_q, &rsa->lock, q, ctx)) {
goto err;
}
}
if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx)) {
goto err;
}
/* compute I mod q */
c = &local_c;
BN_with_flags(c, I, BN_FLG_CONSTTIME);
if (!BN_mod(r1, c, rsa->q, ctx)) {
goto err;
}
/* compute r1^dmq1 mod q */
dmq1 = &local_dmq1;
BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
if (!BN_mod_exp_mont_consttime(m1, r1, dmq1, rsa->q, ctx, rsa->mont_q)) {
goto err;
}
/* compute I mod p */
c = &local_c;
BN_with_flags(c, I, BN_FLG_CONSTTIME);
if (!BN_mod(r1, c, rsa->p, ctx)) {
goto err;
}
/* compute r1^dmp1 mod p */
dmp1 = &local_dmp1;
BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
if (!BN_mod_exp_mont_consttime(r0, r1, dmp1, rsa->p, ctx, rsa->mont_p)) {
goto err;
}
if (!BN_sub(r0, r0, m1)) {
goto err;
}
/* This will help stop the size of r0 increasing, which does
* affect the multiply if it optimised for a power of 2 size */
if (BN_is_negative(r0)) {
if (!BN_add(r0, r0, rsa->p)) {
goto err;
}
}
if (!BN_mul(r1, r0, rsa->iqmp, ctx)) {
goto err;
}
/* Turn BN_FLG_CONSTTIME flag on before division operation */
pr1 = &local_r1;
BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
if (!BN_mod(r0, pr1, rsa->p, ctx)) {
goto err;
}
/* If p < q it is occasionally possible for the correction of
* adding 'p' if r0 is negative above to leave the result still
* negative. This can break the private key operations: the following
* second correction should *always* correct this rare occurrence.
* This will *never* happen with OpenSSL generated keys because
* they ensure p > q [steve] */
if (BN_is_negative(r0)) {
if (!BN_add(r0, r0, rsa->p)) {
goto err;
}
}
if (!BN_mul(r1, r0, rsa->q, ctx)) {
goto err;
}
if (!BN_add(r0, r1, m1)) {
goto err;
}
for (i = 0; i < num_additional_primes; i++) {
/* multi-prime RSA. */
BIGNUM local_exp, local_prime;
BIGNUM *exp = &local_exp, *prime = &local_prime;
RSA_additional_prime *ap =
sk_RSA_additional_prime_value(rsa->additional_primes, i);
BN_with_flags(exp, ap->exp, BN_FLG_CONSTTIME);
BN_with_flags(prime, ap->prime, BN_FLG_CONSTTIME);
/* c will already point to a BIGNUM with the correct flags. */
if (!BN_mod(r1, c, prime, ctx)) {
goto err;
}
if (!BN_MONT_CTX_set_locked(&ap->mont, &rsa->lock, prime, ctx) ||
!BN_mod_exp_mont_consttime(m1, r1, exp, prime, ctx, ap->mont)) {
goto err;
}
BN_set_flags(m1, BN_FLG_CONSTTIME);
if (!BN_sub(m1, m1, r0) ||
!BN_mul(m1, m1, ap->coeff, ctx) ||
!BN_mod(m1, m1, prime, ctx) ||
(BN_is_negative(m1) && !BN_add(m1, m1, prime)) ||
!BN_mul(m1, m1, ap->r, ctx) ||
!BN_add(r0, r0, m1)) {
goto err;
}
}
ret = 1;
err:
BN_CTX_end(ctx);
return ret;
}
int rsa_default_private_transform(RSA *rsa, uint8_t *out, const uint8_t *in,
size_t len) {
BIGNUM *f, *result;
BN_CTX *ctx = NULL;
unsigned blinding_index = 0;
BN_BLINDING *blinding = NULL;
int ret = 0;
ctx = BN_CTX_new();
if (ctx == NULL) {
goto err;
}
BN_CTX_start(ctx);
f = BN_CTX_get(ctx);
result = BN_CTX_get(ctx);
if (f == NULL || result == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
goto err;
}
if (BN_bin2bn(in, len, f) == NULL) {
goto err;
}
if (BN_ucmp(f, rsa->n) >= 0) {
/* Usually the padding functions would catch this. */
OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
goto err;
}
if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
goto err;
}
/* We cannot do blinding or verification without |e|, and continuing without
* those countermeasures is dangerous. However, the Java/Android RSA API
* requires support for keys where only |d| and |n| (and not |e|) are known.
* The callers that require that bad behavior set |RSA_FLAG_NO_BLINDING|. */
int disable_security = (rsa->flags & RSA_FLAG_NO_BLINDING) && rsa->e == NULL;
if (!disable_security) {
/* Keys without public exponents must have blinding explicitly disabled to
* be used. */
if (rsa->e == NULL) {
OPENSSL_PUT_ERROR(RSA, RSA_R_NO_PUBLIC_EXPONENT);
goto err;
}
blinding = rsa_blinding_get(rsa, &blinding_index, ctx);
if (blinding == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
goto err;
}
if (!BN_BLINDING_convert(f, blinding, rsa->e, rsa->mont_n, ctx)) {
goto err;
}
}
if (rsa->p != NULL && rsa->q != NULL && rsa->e != NULL && rsa->dmp1 != NULL &&
rsa->dmq1 != NULL && rsa->iqmp != NULL) {
if (!mod_exp(result, f, rsa, ctx)) {
goto err;
}
} else {
BIGNUM local_d;
BIGNUM *d = NULL;
BN_init(&local_d);
d = &local_d;
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
if (!BN_mod_exp_mont_consttime(result, f, d, rsa->n, ctx, rsa->mont_n)) {
goto err;
}
}
/* Verify the result to protect against fault attacks as described in the
* 1997 paper "On the Importance of Checking Cryptographic Protocols for
* Faults" by Dan Boneh, Richard A. DeMillo, and Richard J. Lipton. Some
* implementations do this only when the CRT is used, but we do it in all
* cases. Section 6 of the aforementioned paper describes an attack that
* works when the CRT isn't used. That attack is much less likely to succeed
* than the CRT attack, but there have likely been improvements since 1997.
*
* This check is cheap assuming |e| is small; it almost always is. */
if (!disable_security) {
BIGNUM *vrfy = BN_CTX_get(ctx);
if (vrfy == NULL ||
!BN_mod_exp_mont(vrfy, result, rsa->e, rsa->n, ctx, rsa->mont_n) ||
!BN_equal_consttime(vrfy, f)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
goto err;
}
if (!BN_BLINDING_invert(result, blinding, rsa->mont_n, ctx)) {
goto err;
}
}
if (!BN_bn2bin_padded(out, len, result)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
goto err;
}
ret = 1;
err:
if (ctx != NULL) {
BN_CTX_end(ctx);
BN_CTX_free(ctx);
}
if (blinding != NULL) {
rsa_blinding_release(rsa, blinding, blinding_index);
}
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, *order = NULL, *X = NULL;
EC_POINT *tmp_point = NULL;
const EC_GROUP *group;
int ret = 0;
if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
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 */
order = BN_new();
X = BN_new();
if (k == NULL || r == NULL || order == 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;
}
if (!EC_GROUP_get_order(group, order, ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
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_rand_range(k, order)) {
ECerr(EC_F_ECDSA_SIGN_SETUP,
EC_R_RANDOM_NUMBER_GENERATION_FAILED);
goto err;
}
}
while (BN_is_zero(k));
/*
* We do not want timing information to leak the length of k, so we
* compute G*k using an equivalent scalar of fixed bit-length.
*/
if (!BN_add(k, k, order))
goto err;
if (BN_num_bits(k) <= BN_num_bits(order))
if (!BN_add(k, k, order))
goto err;
/* 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));
/* compute the inverse of k */
if (EC_GROUP_get_mont_data(group) != 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, EC_GROUP_get_mont_data(group))) {
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);
BN_free(order);
EC_POINT_free(tmp_point);
BN_clear_free(X);
return (ret);
}
static int mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) {
assert(ctx != NULL);
assert(rsa->n != NULL);
assert(rsa->e != NULL);
assert(rsa->d != NULL);
assert(rsa->p != NULL);
assert(rsa->q != NULL);
assert(rsa->dmp1 != NULL);
assert(rsa->dmq1 != NULL);
assert(rsa->iqmp != NULL);
BIGNUM *r1, *m1;
int ret = 0;
BN_CTX_start(ctx);
r1 = BN_CTX_get(ctx);
m1 = BN_CTX_get(ctx);
if (r1 == NULL ||
m1 == NULL) {
goto err;
}
if (!freeze_private_key(rsa, ctx)) {
goto err;
}
// Implementing RSA with CRT in constant-time is sensitive to which prime is
// larger. Canonicalize fields so that |p| is the larger prime.
const BIGNUM *dmp1 = rsa->dmp1_fixed, *dmq1 = rsa->dmq1_fixed;
const BN_MONT_CTX *mont_p = rsa->mont_p, *mont_q = rsa->mont_q;
if (BN_cmp(rsa->p, rsa->q) < 0) {
mont_p = rsa->mont_q;
mont_q = rsa->mont_p;
dmp1 = rsa->dmq1_fixed;
dmq1 = rsa->dmp1_fixed;
}
// Use the minimal-width versions of |n|, |p|, and |q|. Either works, but if
// someone gives us non-minimal values, these will be slightly more efficient
// on the non-Montgomery operations.
const BIGNUM *n = &rsa->mont_n->N;
const BIGNUM *p = &mont_p->N;
const BIGNUM *q = &mont_q->N;
// This is a pre-condition for |mod_montgomery|. It was already checked by the
// caller.
assert(BN_ucmp(I, n) < 0);
if (// |m1| is the result modulo |q|.
!mod_montgomery(r1, I, q, mont_q, p, ctx) ||
!BN_mod_exp_mont_consttime(m1, r1, dmq1, q, ctx, mont_q) ||
// |r0| is the result modulo |p|.
!mod_montgomery(r1, I, p, mont_p, q, ctx) ||
!BN_mod_exp_mont_consttime(r0, r1, dmp1, p, ctx, mont_p) ||
// Compute r0 = r0 - m1 mod p. |p| is the larger prime, so |m1| is already
// fully reduced mod |p|.
!bn_mod_sub_consttime(r0, r0, m1, p, ctx) ||
// r0 = r0 * iqmp mod p. We use Montgomery multiplication to compute this
// in constant time. |inv_small_mod_large_mont| is in Montgomery form and
// r0 is not, so the result is taken out of Montgomery form.
!BN_mod_mul_montgomery(r0, r0, rsa->inv_small_mod_large_mont, mont_p,
ctx) ||
// r0 = r0 * q + m1 gives the final result. Reducing modulo q gives m1, so
// it is correct mod p. Reducing modulo p gives (r0-m1)*iqmp*q + m1 = r0,
// so it is correct mod q. Finally, the result is bounded by [m1, n + m1),
// and the result is at least |m1|, so this must be the unique answer in
// [0, n).
!bn_mul_consttime(r0, r0, q, ctx) ||
!bn_uadd_consttime(r0, r0, m1) ||
// The result should be bounded by |n|, but fixed-width operations may
// bound the width slightly higher, so fix it.
!bn_resize_words(r0, n->width)) {
goto err;
}
ret = 1;
err:
BN_CTX_end(ctx);
return ret;
}
int rsa_default_private_transform(RSA *rsa, uint8_t *out, const uint8_t *in,
size_t len) {
if (rsa->n == NULL || rsa->d == NULL) {
OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING);
return 0;
}
BIGNUM *f, *result;
BN_CTX *ctx = NULL;
unsigned blinding_index = 0;
BN_BLINDING *blinding = NULL;
int ret = 0;
ctx = BN_CTX_new();
if (ctx == NULL) {
goto err;
}
BN_CTX_start(ctx);
f = BN_CTX_get(ctx);
result = BN_CTX_get(ctx);
if (f == NULL || result == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
goto err;
}
if (BN_bin2bn(in, len, f) == NULL) {
goto err;
}
if (BN_ucmp(f, rsa->n) >= 0) {
// Usually the padding functions would catch this.
OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE);
goto err;
}
if (!freeze_private_key(rsa, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
goto err;
}
const int do_blinding = (rsa->flags & RSA_FLAG_NO_BLINDING) == 0;
if (rsa->e == NULL && do_blinding) {
// We cannot do blinding or verification without |e|, and continuing without
// those countermeasures is dangerous. However, the Java/Android RSA API
// requires support for keys where only |d| and |n| (and not |e|) are known.
// The callers that require that bad behavior set |RSA_FLAG_NO_BLINDING|.
OPENSSL_PUT_ERROR(RSA, RSA_R_NO_PUBLIC_EXPONENT);
goto err;
}
if (do_blinding) {
blinding = rsa_blinding_get(rsa, &blinding_index, ctx);
if (blinding == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
goto err;
}
if (!BN_BLINDING_convert(f, blinding, rsa->e, rsa->mont_n, ctx)) {
goto err;
}
}
if (rsa->p != NULL && rsa->q != NULL && rsa->e != NULL && rsa->dmp1 != NULL &&
rsa->dmq1 != NULL && rsa->iqmp != NULL) {
if (!mod_exp(result, f, rsa, ctx)) {
goto err;
}
} else if (!BN_mod_exp_mont_consttime(result, f, rsa->d_fixed, rsa->n, ctx,
rsa->mont_n)) {
goto err;
}
// Verify the result to protect against fault attacks as described in the
// 1997 paper "On the Importance of Checking Cryptographic Protocols for
// Faults" by Dan Boneh, Richard A. DeMillo, and Richard J. Lipton. Some
// implementations do this only when the CRT is used, but we do it in all
// cases. Section 6 of the aforementioned paper describes an attack that
// works when the CRT isn't used. That attack is much less likely to succeed
// than the CRT attack, but there have likely been improvements since 1997.
//
// This check is cheap assuming |e| is small; it almost always is.
if (rsa->e != NULL) {
BIGNUM *vrfy = BN_CTX_get(ctx);
if (vrfy == NULL ||
!BN_mod_exp_mont(vrfy, result, rsa->e, rsa->n, ctx, rsa->mont_n) ||
!BN_equal_consttime(vrfy, f)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
goto err;
}
}
if (do_blinding &&
!BN_BLINDING_invert(result, blinding, rsa->mont_n, ctx)) {
goto err;
}
// The computation should have left |result| as a maximally-wide number, so
// that it and serializing does not leak information about the magnitude of
// the result.
//
// See Falko Stenzke, "Manger's Attack revisited", ICICS 2010.
assert(result->width == rsa->mont_n->N.width);
if (!BN_bn2bin_padded(out, len, result)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
goto err;
}
ret = 1;
err:
if (ctx != NULL) {
BN_CTX_end(ctx);
BN_CTX_free(ctx);
}
if (blinding != NULL) {
rsa_blinding_release(rsa, blinding, blinding_index);
}
return ret;
}
static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
BIGNUM **rp)
{
BN_CTX *ctx = NULL;
BIGNUM *k = NULL, *r = NULL, *order = NULL, *X = NULL;
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) {
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
if (ctx_in == NULL) {
if ((ctx = BN_CTX_new()) == NULL) {
ECDSAerr(ECDSA_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 */
order = BN_new();
X = BN_new();
if (!k || !r || !order || !X) {
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
goto err;
}
if ((tmp_point = EC_POINT_new(group)) == NULL) {
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
goto err;
}
if (!EC_GROUP_get_order(group, order, ctx)) {
ECDSAerr(ECDSA_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 (!BN_rand_range(k, order)) {
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,
ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED);
goto err;
}
while (BN_is_zero(k)) ;
/*
* We do not want timing information to leak the length of k, so we
* compute G*k using an equivalent scalar of fixed bit-length.
*
* We unconditionally perform both of these additions to prevent a
* small timing information leakage. We then choose the sum that is
* one bit longer than the order. This guarantees the code
* path used in the constant time implementations elsewhere.
*
* TODO: revisit the BN_copy aiming for a memory access agnostic
* conditional copy.
*/
if (!BN_add(r, k, order)
|| !BN_add(X, r, order)
|| !BN_copy(k, BN_num_bits(r) > order_bits ? r : X))
goto err;
/* compute r the x-coordinate of generator * k */
if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx)) {
ECDSAerr(ECDSA_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)) {
ECDSAerr(ECDSA_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)) {
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
goto err;
}
}
#endif
if (!BN_nnmod(r, X, order, ctx)) {
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
goto err;
}
}
while (BN_is_zero(r));
/* compute the inverse of k */
if (EC_GROUP_get_mont_data(group) != 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)) {
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
goto err;
}
if (!BN_mod_sub(X, order, X, order, ctx)) {
ECDSAerr(ECDSA_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, EC_GROUP_get_mont_data(group))) {
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
goto err;
}
} else {
if (!BN_mod_inverse(k, k, order, ctx)) {
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
goto err;
}
}
/* clear old values if necessary */
if (*rp != NULL)
BN_clear_free(*rp);
if (*kinvp != NULL)
BN_clear_free(*kinvp);
/* save the pre-computed values */
*rp = r;
*kinvp = k;
ret = 1;
err:
if (!ret) {
if (k != NULL)
BN_clear_free(k);
if (r != NULL)
BN_clear_free(r);
}
if (ctx_in == NULL)
BN_CTX_free(ctx);
if (order != NULL)
BN_free(order);
if (tmp_point != NULL)
EC_POINT_free(tmp_point);
if (X)
BN_clear_free(X);
return (ret);
}
int main(int argc, char *argv[])
{
BN_CTX *ctx;
BIO *out = NULL;
int i, ret;
unsigned char c;
BIGNUM *r_mont, *r_mont_const, *r_recp, *r_simple, *a, *b, *m;
RAND_seed(rnd_seed, sizeof rnd_seed); /* or BN_rand may fail, and we
* don't even check its return
* value (which we should) */
ERR_load_BN_strings();
ctx = BN_CTX_new();
if (ctx == NULL)
EXIT(1);
r_mont = BN_new();
r_mont_const = BN_new();
r_recp = BN_new();
r_simple = BN_new();
a = BN_new();
b = BN_new();
m = BN_new();
if ((r_mont == NULL) || (r_recp == NULL) || (a == NULL) || (b == NULL))
goto err;
out = BIO_new(BIO_s_file());
if (out == NULL)
EXIT(1);
BIO_set_fp(out, stdout, BIO_NOCLOSE);
for (i = 0; i < 200; i++) {
RAND_bytes(&c, 1);
c = (c % BN_BITS) - BN_BITS2;
BN_rand(a, NUM_BITS + c, 0, 0);
RAND_bytes(&c, 1);
c = (c % BN_BITS) - BN_BITS2;
BN_rand(b, NUM_BITS + c, 0, 0);
RAND_bytes(&c, 1);
c = (c % BN_BITS) - BN_BITS2;
BN_rand(m, NUM_BITS + c, 0, 1);
BN_mod(a, a, m, ctx);
BN_mod(b, b, m, ctx);
ret = BN_mod_exp_mont(r_mont, a, b, m, ctx, NULL);
if (ret <= 0) {
printf("BN_mod_exp_mont() problems\n");
ERR_print_errors(out);
EXIT(1);
}
ret = BN_mod_exp_recp(r_recp, a, b, m, ctx);
if (ret <= 0) {
printf("BN_mod_exp_recp() problems\n");
ERR_print_errors(out);
EXIT(1);
}
ret = BN_mod_exp_simple(r_simple, a, b, m, ctx);
if (ret <= 0) {
printf("BN_mod_exp_simple() problems\n");
ERR_print_errors(out);
EXIT(1);
}
ret = BN_mod_exp_mont_consttime(r_mont_const, a, b, m, ctx, NULL);
if (ret <= 0) {
printf("BN_mod_exp_mont_consttime() problems\n");
ERR_print_errors(out);
EXIT(1);
}
if (BN_cmp(r_simple, r_mont) == 0
&& BN_cmp(r_simple, r_recp) == 0
&& BN_cmp(r_simple, r_mont_const) == 0) {
printf(".");
fflush(stdout);
} else {
if (BN_cmp(r_simple, r_mont) != 0)
printf("\nsimple and mont results differ\n");
if (BN_cmp(r_simple, r_mont_const) != 0)
printf("\nsimple and mont const time results differ\n");
if (BN_cmp(r_simple, r_recp) != 0)
printf("\nsimple and recp results differ\n");
printf("a (%3d) = ", BN_num_bits(a));
BN_print(out, a);
printf("\nb (%3d) = ", BN_num_bits(b));
BN_print(out, b);
printf("\nm (%3d) = ", BN_num_bits(m));
BN_print(out, m);
printf("\nsimple =");
BN_print(out, r_simple);
printf("\nrecp =");
BN_print(out, r_recp);
printf("\nmont =");
BN_print(out, r_mont);
printf("\nmont_ct =");
BN_print(out, r_mont_const);
printf("\n");
EXIT(1);
}
}
BN_free(r_mont);
BN_free(r_mont_const);
BN_free(r_recp);
BN_free(r_simple);
BN_free(a);
BN_free(b);
BN_free(m);
BN_CTX_free(ctx);
ERR_remove_thread_state(NULL);
CRYPTO_mem_leaks(out);
BIO_free(out);
printf("\n");
if (test_exp_mod_zero() != 0)
goto err;
printf("done\n");
EXIT(0);
err:
ERR_load_crypto_strings();
ERR_print_errors(out);
#ifdef OPENSSL_SYS_NETWARE
printf("ERROR\n");
#endif
EXIT(1);
return (1);
}
/*
* test_exp_mod_zero tests that x**0 mod 1 == 0. It returns zero on success.
*/
static int test_exp_mod_zero()
{
BIGNUM *a = NULL, *p = NULL, *m = NULL;
BIGNUM *r = NULL;
BN_ULONG one_word = 1;
BN_CTX *ctx = BN_CTX_new();
int ret = 1, failed = 0;
m = BN_new();
if (!m)
goto err;
BN_one(m);
a = BN_new();
if (!a)
goto err;
BN_one(a);
p = BN_new();
if (!p)
goto err;
BN_zero(p);
r = BN_new();
if (!r)
goto err;
if (!BN_rand(a, 1024, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY))
goto err;
if (!BN_mod_exp(r, a, p, m, ctx))
goto err;
if (!a_is_zero_mod_one("BN_mod_exp", r, a))
failed = 1;
if (!BN_mod_exp_recp(r, a, p, m, ctx))
goto err;
if (!a_is_zero_mod_one("BN_mod_exp_recp", r, a))
failed = 1;
if (!BN_mod_exp_simple(r, a, p, m, ctx))
goto err;
if (!a_is_zero_mod_one("BN_mod_exp_simple", r, a))
failed = 1;
if (!BN_mod_exp_mont(r, a, p, m, ctx, NULL))
goto err;
if (!a_is_zero_mod_one("BN_mod_exp_mont", r, a))
failed = 1;
if (!BN_mod_exp_mont_consttime(r, a, p, m, ctx, NULL)) {
goto err;
}
if (!a_is_zero_mod_one("BN_mod_exp_mont_consttime", r, a))
failed = 1;
/*
* A different codepath exists for single word multiplication
* in non-constant-time only.
*/
if (!BN_mod_exp_mont_word(r, one_word, p, m, ctx, NULL))
goto err;
if (!BN_is_zero(r)) {
fprintf(stderr, "BN_mod_exp_mont_word failed:\n");
fprintf(stderr, "1 ** 0 mod 1 = r (should be 0)\n");
fprintf(stderr, "r = ");
BN_print_fp(stderr, r);
fprintf(stderr, "\n");
return 0;
}
ret = failed;
err:
BN_free(r);
BN_free(a);
BN_free(p);
BN_free(m);
BN_CTX_free(ctx);
return ret;
}
int DH_generate_key(DH *dh) {
int ok = 0;
int generate_new_key = 0;
BN_CTX *ctx = NULL;
BIGNUM *pub_key = NULL, *priv_key = NULL;
if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) {
OPENSSL_PUT_ERROR(DH, DH_R_MODULUS_TOO_LARGE);
goto err;
}
ctx = BN_CTX_new();
if (ctx == NULL) {
goto err;
}
if (dh->priv_key == NULL) {
priv_key = BN_new();
if (priv_key == NULL) {
goto err;
}
generate_new_key = 1;
} else {
priv_key = dh->priv_key;
}
if (dh->pub_key == NULL) {
pub_key = BN_new();
if (pub_key == NULL) {
goto err;
}
} else {
pub_key = dh->pub_key;
}
if (!BN_MONT_CTX_set_locked(&dh->method_mont_p, &dh->method_mont_p_lock,
dh->p, ctx)) {
goto err;
}
if (generate_new_key) {
if (dh->q) {
if (!BN_rand_range_ex(priv_key, 2, dh->q)) {
goto err;
}
} else {
// secret exponent length
unsigned priv_bits = dh->priv_length;
if (priv_bits == 0) {
const unsigned p_bits = BN_num_bits(dh->p);
if (p_bits == 0) {
goto err;
}
priv_bits = p_bits - 1;
}
if (!BN_rand(priv_key, priv_bits, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY)) {
goto err;
}
}
}
if (!BN_mod_exp_mont_consttime(pub_key, dh->g, priv_key, dh->p, ctx,
dh->method_mont_p)) {
goto err;
}
dh->pub_key = pub_key;
dh->priv_key = priv_key;
ok = 1;
err:
if (ok != 1) {
OPENSSL_PUT_ERROR(DH, ERR_R_BN_LIB);
}
if (dh->pub_key == NULL) {
BN_free(pub_key);
}
if (dh->priv_key == NULL) {
BN_free(priv_key);
}
BN_CTX_free(ctx);
return ok;
}
/*
* test_mod_exp_zero tests that x**0 mod 1 == 0. It returns zero on success.
*/
static int test_mod_exp_zero(void)
{
BIGNUM *a = NULL, *p = NULL, *m = NULL;
BIGNUM *r = NULL;
BN_ULONG one_word = 1;
BN_CTX *ctx = BN_CTX_new();
int ret = 1, failed = 0;
if (!TEST_ptr(m = BN_new())
|| !TEST_ptr(a = BN_new())
|| !TEST_ptr(p = BN_new())
|| !TEST_ptr(r = BN_new()))
goto err;
BN_one(m);
BN_one(a);
BN_zero(p);
if (!TEST_true(BN_rand(a, 1024, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY)))
goto err;
if (!TEST_true(BN_mod_exp(r, a, p, m, ctx)))
goto err;
if (!TEST_true(a_is_zero_mod_one("BN_mod_exp", r, a)))
failed = 1;
if (!TEST_true(BN_mod_exp_recp(r, a, p, m, ctx)))
goto err;
if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_recp", r, a)))
failed = 1;
if (!TEST_true(BN_mod_exp_simple(r, a, p, m, ctx)))
goto err;
if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_simple", r, a)))
failed = 1;
if (!TEST_true(BN_mod_exp_mont(r, a, p, m, ctx, NULL)))
goto err;
if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_mont", r, a)))
failed = 1;
if (!TEST_true(BN_mod_exp_mont_consttime(r, a, p, m, ctx, NULL)))
goto err;
if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_mont_consttime", r, a)))
failed = 1;
/*
* A different codepath exists for single word multiplication
* in non-constant-time only.
*/
if (!TEST_true(BN_mod_exp_mont_word(r, one_word, p, m, ctx, NULL)))
goto err;
if (!TEST_BN_eq_zero(r)) {
TEST_error("BN_mod_exp_mont_word failed: "
"1 ** 0 mod 1 = r (should be 0)");
BN_print_var(r);
goto err;
}
ret = !failed;
err:
BN_free(r);
BN_free(a);
BN_free(p);
BN_free(m);
BN_CTX_free(ctx);
return ret;
}
static int test_mod_exp(int round)
{
BN_CTX *ctx;
unsigned char c;
int ret = 0;
BIGNUM *r_mont = NULL;
BIGNUM *r_mont_const = NULL;
BIGNUM *r_recp = NULL;
BIGNUM *r_simple = NULL;
BIGNUM *a = NULL;
BIGNUM *b = NULL;
BIGNUM *m = NULL;
if (!TEST_ptr(ctx = BN_CTX_new()))
goto err;
if (!TEST_ptr(r_mont = BN_new())
|| !TEST_ptr(r_mont_const = BN_new())
|| !TEST_ptr(r_recp = BN_new())
|| !TEST_ptr(r_simple = BN_new())
|| !TEST_ptr(a = BN_new())
|| !TEST_ptr(b = BN_new())
|| !TEST_ptr(m = BN_new()))
goto err;
RAND_bytes(&c, 1);
c = (c % BN_BITS) - BN_BITS2;
BN_rand(a, NUM_BITS + c, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY);
RAND_bytes(&c, 1);
c = (c % BN_BITS) - BN_BITS2;
BN_rand(b, NUM_BITS + c, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY);
RAND_bytes(&c, 1);
c = (c % BN_BITS) - BN_BITS2;
BN_rand(m, NUM_BITS + c, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD);
if (!TEST_true(BN_mod(a, a, m, ctx))
|| !TEST_true(BN_mod(b, b, m, ctx))
|| !TEST_true(BN_mod_exp_mont(r_mont, a, b, m, ctx, NULL))
|| !TEST_true(BN_mod_exp_recp(r_recp, a, b, m, ctx))
|| !TEST_true(BN_mod_exp_simple(r_simple, a, b, m, ctx))
|| !TEST_true(BN_mod_exp_mont_consttime(r_mont_const, a, b, m, ctx, NULL)))
goto err;
if (!TEST_BN_eq(r_simple, r_mont)
|| !TEST_BN_eq(r_simple, r_recp)
|| !TEST_BN_eq(r_simple, r_mont_const)) {
if (BN_cmp(r_simple, r_mont) != 0)
TEST_info("simple and mont results differ");
if (BN_cmp(r_simple, r_mont_const) != 0)
TEST_info("simple and mont const time results differ");
if (BN_cmp(r_simple, r_recp) != 0)
TEST_info("simple and recp results differ");
BN_print_var(a);
BN_print_var(b);
BN_print_var(m);
BN_print_var(r_simple);
BN_print_var(r_recp);
BN_print_var(r_mont);
BN_print_var(r_mont_const);
goto err;
}
ret = 1;
err:
BN_free(r_mont);
BN_free(r_mont_const);
BN_free(r_recp);
BN_free(r_simple);
BN_free(a);
BN_free(b);
BN_free(m);
BN_CTX_free(ctx);
return ret;
}
int exp_main(int argc, char *argv[])
#endif
{
BN_CTX *ctx;
BIO *out=NULL;
int i,ret;
unsigned char c;
BIGNUM *r_mont,*r_mont_const,*r_recp,*r_simple,*a,*b,*m;
// FILE* temp;
RAND_seed(rnd_seed, sizeof rnd_seed); /* or BN_rand may fail, and we don't
* even check its return value
* (which we should) */
if(errno==ENOMEM)
{
return 1;
}
ERR_load_BN_strings();
if(errno==ENOMEM)
{
return 1;
}
ctx=BN_CTX_new();
if (ctx == NULL)
{
if(errno==ENOMEM)
{
return 1;
}
return 1;
}
r_mont=BN_new();
if(r_mont==NULL&&errno==ENOMEM)
{
return 1;
}
r_mont_const=BN_new();
if(r_mont_const==NULL&&errno==ENOMEM)
{
return 1;
}
r_recp=BN_new();
if(r_recp==NULL&&errno==ENOMEM)
{
return 1;
}
r_simple=BN_new();
if(r_simple==NULL&&errno==ENOMEM)
{
return 1;
}
a=BN_new();
if(a==NULL&&errno==ENOMEM)
{
return 1;
}
b=BN_new();
if(b==NULL&&errno==ENOMEM)
{
return 1;
}
m=BN_new();
if(m==NULL&&errno==ENOMEM)
{
return 1;
}
if ( (r_mont == NULL) || (r_recp == NULL) ||
(a == NULL) || (b == NULL))
goto err;
out=BIO_new(BIO_s_file());
if(out==NULL&&errno==ENOMEM)
{
return 1;
}
if (out == NULL)
return 1;
BIO_set_fp(out,stdout,BIO_NOCLOSE);
if(errno==ENOMEM)
{
return 1;
}
// temp = fopen("sanjeev.txt", "w");
for (i=0; i<200; i++)
{
// fputc(i,temp);
RAND_bytes(&c,1);
if(errno==ENOMEM)
{
return 1;
}
c=(c%BN_BITS)-BN_BITS2;
BN_rand(a,NUM_BITS+c,0,0);
if(errno==ENOMEM)
{
return 1;
}
RAND_bytes(&c,1);
if(errno==ENOMEM)
{
return 1;
}
c=(c%BN_BITS)-BN_BITS2;
BN_rand(b,NUM_BITS+c,0,0);
if(errno==ENOMEM)
{
return 1;
}
RAND_bytes(&c,1);
if(errno==ENOMEM)
{
return 1;
}
c=(c%BN_BITS)-BN_BITS2;
BN_rand(m,NUM_BITS+c,0,1);
if(errno==ENOMEM)
{
return 1;
}
BN_mod(a,a,m,ctx);
if(errno==ENOMEM)
{
return 1;
}
BN_mod(b,b,m,ctx);
if(errno==ENOMEM)
{
return 1;
}
ret=BN_mod_exp_mont(r_mont,a,b,m,ctx,NULL);
if (ret <= 0)
{
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"BN_mod_exp_mont() problems\n");
ERR_print_errors(out);
if(errno==ENOMEM)
{
return 1;
}
return 1;
}
ret=BN_mod_exp_recp(r_recp,a,b,m,ctx);
if (ret <= 0)
{
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"BN_mod_exp_recp() problems\n");
ERR_print_errors(out);
if(errno==ENOMEM)
{
return 1;
}
return 1;
}
ret=BN_mod_exp_simple(r_simple,a,b,m,ctx);
if (ret <= 0)
{
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"BN_mod_exp_simple() problems\n");
ERR_print_errors(out);
if(errno==ENOMEM)
{
return 1;
}
return 1;
}
ret=BN_mod_exp_mont_consttime(r_mont_const,a,b,m,ctx,NULL);
if (ret <= 0)
{
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"BN_mod_exp_mont_consttime() problems\n");
ERR_print_errors(out);
if(errno==ENOMEM)
{
return 1;
}
return 1;
}
if (BN_cmp(r_simple, r_mont) == 0
&& BN_cmp(r_simple,r_recp) == 0
&& BN_cmp(r_simple,r_mont_const) == 0)
{
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,".");
fflush(stdout);
}
else
{
if (BN_cmp(r_simple,r_mont) != 0)
{
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"\nsimple and mont results differ\n");
}
if (BN_cmp(r_simple,r_mont) != 0)
{
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"\nsimple and mont const time results differ\n");
}
if (BN_cmp(r_simple,r_recp) != 0)
{
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"\nsimple and recp results differ\n");
}
fprintf(stdout,"a (%3d) = ",BN_num_bits(a));
BN_print(out,a);
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"\nb (%3d) = ",BN_num_bits(b));
BN_print(out,b);
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"\nm (%3d) = ",BN_num_bits(m));
BN_print(out,m);
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"\nsimple =");
BN_print(out,r_simple);
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"\nrecp =");
BN_print(out,r_recp);
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"\nmont =");
BN_print(out,r_mont);
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"\nmont_ct =");
BN_print(out,r_mont_const);
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout,"\n");
return 1;
}
}
BN_free(r_mont);
BN_free(r_mont_const);
BN_free(r_recp);
BN_free(r_simple);
BN_free(a);
BN_free(b);
BN_free(m);
BN_CTX_free(ctx);
ERR_remove_state(0);
if(errno==ENOMEM)
{
return 1;
}
CRYPTO_mem_leaks(out);
if(errno==ENOMEM)
{
return 1;
}
BIO_free(out);
if(errno==ENOMEM)
{
return 1;
}
CRYPTO_cleanup_all_ex_data();
if(errno==ENOMEM)
{
return 1;
}
fprintf(stdout," done\n");
fprintf(stdout," Test case passed\n");
return 0;
err:
ERR_load_crypto_strings();
if(errno==ENOMEM)
{
return 1;
}
ERR_print_errors(out);
if(errno==ENOMEM)
{
return 1;
}
#ifdef OPENSSL_SYS_NETWARE
fprintf(stdout,"ERROR\n");
#endif
return(1);
}
static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
{
BIGNUM *r1, *m1, *vrfy, *r2, *m[RSA_MAX_PRIME_NUM - 2];
int ret = 0, i, ex_primes = 0, smooth = 0;
RSA_PRIME_INFO *pinfo;
BN_CTX_start(ctx);
r1 = BN_CTX_get(ctx);
r2 = BN_CTX_get(ctx);
m1 = BN_CTX_get(ctx);
vrfy = BN_CTX_get(ctx);
if (vrfy == NULL)
goto err;
if (rsa->version == RSA_ASN1_VERSION_MULTI
&& ((ex_primes = sk_RSA_PRIME_INFO_num(rsa->prime_infos)) <= 0
|| ex_primes > RSA_MAX_PRIME_NUM - 2))
goto err;
if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
BIGNUM *factor = BN_new();
if (factor == NULL)
goto err;
/*
* Make sure BN_mod_inverse in Montgomery initialization uses the
* BN_FLG_CONSTTIME flag
*/
if (!(BN_with_flags(factor, rsa->p, BN_FLG_CONSTTIME),
BN_MONT_CTX_set_locked(&rsa->_method_mod_p, rsa->lock,
factor, ctx))
|| !(BN_with_flags(factor, rsa->q, BN_FLG_CONSTTIME),
BN_MONT_CTX_set_locked(&rsa->_method_mod_q, rsa->lock,
factor, ctx))) {
BN_free(factor);
goto err;
}
for (i = 0; i < ex_primes; i++) {
pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i);
BN_with_flags(factor, pinfo->r, BN_FLG_CONSTTIME);
if (!BN_MONT_CTX_set_locked(&pinfo->m, rsa->lock, factor, ctx)) {
BN_free(factor);
goto err;
}
}
/*
* We MUST free |factor| before any further use of the prime factors
*/
BN_free(factor);
smooth = (ex_primes == 0)
&& (rsa->meth->bn_mod_exp == BN_mod_exp_mont)
&& (BN_num_bits(rsa->q) == BN_num_bits(rsa->p));
}
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock,
rsa->n, ctx))
goto err;
if (smooth) {
/*
* Conversion from Montgomery domain, a.k.a. Montgomery reduction,
* accepts values in [0-m*2^w) range. w is m's bit width rounded up
* to limb width. So that at the very least if |I| is fully reduced,
* i.e. less than p*q, we can count on from-to round to perform
* below modulo operations on |I|. Unlike BN_mod it's constant time.
*/
if (/* m1 = I moq q */
!bn_from_mont_fixed_top(m1, I, rsa->_method_mod_q, ctx)
|| !bn_to_mont_fixed_top(m1, m1, rsa->_method_mod_q, ctx)
/* m1 = m1^dmq1 mod q */
|| !BN_mod_exp_mont_consttime(m1, m1, rsa->dmq1, rsa->q, ctx,
rsa->_method_mod_q)
/* r1 = I mod p */
|| !bn_from_mont_fixed_top(r1, I, rsa->_method_mod_p, ctx)
|| !bn_to_mont_fixed_top(r1, r1, rsa->_method_mod_p, ctx)
/* r1 = r1^dmp1 mod p */
|| !BN_mod_exp_mont_consttime(r1, r1, rsa->dmp1, rsa->p, ctx,
rsa->_method_mod_p)
/* r1 = (r1 - m1) mod p */
/*
* bn_mod_sub_fixed_top is not regular modular subtraction,
* it can tolerate subtrahend to be larger than modulus, but
* not bit-wise wider. This makes up for uncommon q>p case,
* when |m1| can be larger than |rsa->p|.
*/
|| !bn_mod_sub_fixed_top(r1, r1, m1, rsa->p)
/* r1 = r1 * iqmp mod p */
|| !bn_to_mont_fixed_top(r1, r1, rsa->_method_mod_p, ctx)
|| !bn_mul_mont_fixed_top(r1, r1, rsa->iqmp, rsa->_method_mod_p,
ctx)
/* r0 = r1 * q + m1 */
|| !bn_mul_fixed_top(r0, r1, rsa->q, ctx)
|| !bn_mod_add_fixed_top(r0, r0, m1, rsa->n))
goto err;
goto tail;
}
/* compute I mod q */
{
BIGNUM *c = BN_new();
if (c == NULL)
goto err;
BN_with_flags(c, I, BN_FLG_CONSTTIME);
if (!BN_mod(r1, c, rsa->q, ctx)) {
BN_free(c);
goto err;
}
{
BIGNUM *dmq1 = BN_new();
if (dmq1 == NULL) {
BN_free(c);
goto err;
}
BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
/* compute r1^dmq1 mod q */
if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx,
rsa->_method_mod_q)) {
BN_free(c);
BN_free(dmq1);
goto err;
}
/* We MUST free dmq1 before any further use of rsa->dmq1 */
BN_free(dmq1);
}
/* compute I mod p */
if (!BN_mod(r1, c, rsa->p, ctx)) {
BN_free(c);
goto err;
}
/* We MUST free c before any further use of I */
BN_free(c);
}
{
BIGNUM *dmp1 = BN_new();
if (dmp1 == NULL)
goto err;
BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
/* compute r1^dmp1 mod p */
if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx,
rsa->_method_mod_p)) {
BN_free(dmp1);
goto err;
}
/* We MUST free dmp1 before any further use of rsa->dmp1 */
BN_free(dmp1);
}
/*
* calculate m_i in multi-prime case
*
* TODO:
* 1. squash the following two loops and calculate |m_i| there.
* 2. remove cc and reuse |c|.
* 3. remove |dmq1| and |dmp1| in previous block and use |di|.
*
* If these things are done, the code will be more readable.
*/
if (ex_primes > 0) {
BIGNUM *di = BN_new(), *cc = BN_new();
if (cc == NULL || di == NULL) {
BN_free(cc);
BN_free(di);
goto err;
}
for (i = 0; i < ex_primes; i++) {
/* prepare m_i */
if ((m[i] = BN_CTX_get(ctx)) == NULL) {
BN_free(cc);
BN_free(di);
goto err;
}
pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i);
/* prepare c and d_i */
BN_with_flags(cc, I, BN_FLG_CONSTTIME);
BN_with_flags(di, pinfo->d, BN_FLG_CONSTTIME);
if (!BN_mod(r1, cc, pinfo->r, ctx)) {
BN_free(cc);
BN_free(di);
goto err;
}
/* compute r1 ^ d_i mod r_i */
if (!rsa->meth->bn_mod_exp(m[i], r1, di, pinfo->r, ctx, pinfo->m)) {
BN_free(cc);
BN_free(di);
goto err;
}
}
BN_free(cc);
BN_free(di);
}
if (!BN_sub(r0, r0, m1))
goto err;
/*
* This will help stop the size of r0 increasing, which does affect the
* multiply if it optimised for a power of 2 size
*/
if (BN_is_negative(r0))
if (!BN_add(r0, r0, rsa->p))
goto err;
if (!BN_mul(r1, r0, rsa->iqmp, ctx))
goto err;
{
BIGNUM *pr1 = BN_new();
if (pr1 == NULL)
goto err;
BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
if (!BN_mod(r0, pr1, rsa->p, ctx)) {
BN_free(pr1);
goto err;
}
/* We MUST free pr1 before any further use of r1 */
BN_free(pr1);
}
/*
* If p < q it is occasionally possible for the correction of adding 'p'
* if r0 is negative above to leave the result still negative. This can
* break the private key operations: the following second correction
* should *always* correct this rare occurrence. This will *never* happen
* with OpenSSL generated keys because they ensure p > q [steve]
*/
if (BN_is_negative(r0))
if (!BN_add(r0, r0, rsa->p))
goto err;
if (!BN_mul(r1, r0, rsa->q, ctx))
goto err;
if (!BN_add(r0, r1, m1))
goto err;
/* add m_i to m in multi-prime case */
if (ex_primes > 0) {
BIGNUM *pr2 = BN_new();
if (pr2 == NULL)
goto err;
for (i = 0; i < ex_primes; i++) {
pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i);
if (!BN_sub(r1, m[i], r0)) {
BN_free(pr2);
goto err;
}
if (!BN_mul(r2, r1, pinfo->t, ctx)) {
BN_free(pr2);
goto err;
}
BN_with_flags(pr2, r2, BN_FLG_CONSTTIME);
if (!BN_mod(r1, pr2, pinfo->r, ctx)) {
BN_free(pr2);
goto err;
}
if (BN_is_negative(r1))
if (!BN_add(r1, r1, pinfo->r)) {
BN_free(pr2);
goto err;
}
if (!BN_mul(r1, r1, pinfo->pp, ctx)) {
BN_free(pr2);
goto err;
}
if (!BN_add(r0, r0, r1)) {
BN_free(pr2);
goto err;
}
}
BN_free(pr2);
}
tail:
if (rsa->e && rsa->n) {
if (rsa->meth->bn_mod_exp == BN_mod_exp_mont) {
if (!BN_mod_exp_mont(vrfy, r0, rsa->e, rsa->n, ctx,
rsa->_method_mod_n))
goto err;
} else {
bn_correct_top(r0);
if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,
rsa->_method_mod_n))
goto err;
}
/*
* If 'I' was greater than (or equal to) rsa->n, the operation will
* be equivalent to using 'I mod n'. However, the result of the
* verify will *always* be less than 'n' so we don't check for
* absolute equality, just congruency.
*/
if (!BN_sub(vrfy, vrfy, I))
goto err;
if (BN_is_zero(vrfy)) {
bn_correct_top(r0);
ret = 1;
goto err; /* not actually error */
}
if (!BN_mod(vrfy, vrfy, rsa->n, ctx))
goto err;
if (BN_is_negative(vrfy))
if (!BN_add(vrfy, vrfy, rsa->n))
goto err;
if (!BN_is_zero(vrfy)) {
/*
* 'I' and 'vrfy' aren't congruent mod n. Don't leak
* miscalculated CRT output, just do a raw (slower) mod_exp and
* return that instead.
*/
BIGNUM *d = BN_new();
if (d == NULL)
goto err;
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
rsa->_method_mod_n)) {
BN_free(d);
goto err;
}
/* We MUST free d before any further use of rsa->d */
BN_free(d);
}
}
/*
* It's unfortunate that we have to bn_correct_top(r0). What hopefully
* saves the day is that correction is highly unlike, and private key
* operations are customarily performed on blinded message. Which means
* that attacker won't observe correlation with chosen plaintext.
* Secondly, remaining code would still handle it in same computational
* time and even conceal memory access pattern around corrected top.
*/
bn_correct_top(r0);
ret = 1;
err:
BN_CTX_end(ctx);
return ret;
}
/*
* test_exp_mod_zero tests that x**0 mod 1 == 0. It returns zero on success.
*/
static int test_exp_mod_zero(void)
{
BIGNUM a, p, m;
BIGNUM r;
BN_ULONG one_word = 1;
BN_CTX *ctx = BN_CTX_new();
int ret = 1, failed = 0;
BN_init(&m);
BN_one(&m);
BN_init(&a);
BN_one(&a);
BN_init(&p);
BN_zero(&p);
BN_init(&r);
if (!BN_rand(&a, 1024, 0, 0))
goto err;
if (!BN_mod_exp(&r, &a, &p, &m, ctx))
goto err;
if (!a_is_zero_mod_one("BN_mod_exp", &r, &a))
failed = 1;
if (!BN_mod_exp_recp(&r, &a, &p, &m, ctx))
goto err;
if (!a_is_zero_mod_one("BN_mod_exp_recp", &r, &a))
failed = 1;
if (!BN_mod_exp_simple(&r, &a, &p, &m, ctx))
goto err;
if (!a_is_zero_mod_one("BN_mod_exp_simple", &r, &a))
failed = 1;
if (!BN_mod_exp_mont(&r, &a, &p, &m, ctx, NULL))
goto err;
if (!a_is_zero_mod_one("BN_mod_exp_mont", &r, &a))
failed = 1;
if (!BN_mod_exp_mont_consttime(&r, &a, &p, &m, ctx, NULL)) {
goto err;
}
if (!a_is_zero_mod_one("BN_mod_exp_mont_consttime", &r, &a))
failed = 1;
/*
* A different codepath exists for single word multiplication
* in non-constant-time only.
*/
if (!BN_mod_exp_mont_word(&r, one_word, &p, &m, ctx, NULL))
goto err;
if (!BN_is_zero(&r)) {
fprintf(stderr, "BN_mod_exp_mont_word failed:\n");
fprintf(stderr, "1 ** 0 mod 1 = r (should be 0)\n");
fprintf(stderr, "r = ");
BN_print_fp(stderr, &r);
fprintf(stderr, "\n");
return 0;
}
ret = failed;
err:
BN_free(&r);
BN_free(&a);
BN_free(&p);
BN_free(&m);
BN_CTX_free(ctx);
return ret;
}
