Make return value of |BN_MONT_CTX_set_locked| int.

This reduces the chance of double-frees.

BUG=10

Change-Id: I11a240e2ea5572effeddc05acb94db08c54a2e0b
Reviewed-on: https://boringssl-review.googlesource.com/7583
Reviewed-by: David Benjamin <davidben@google.com>
This commit is contained in:
Brian Smith 2016-03-25 10:11:04 -10:00 committed by David Benjamin
parent 51b0d5b1e8
commit d035730ac7
5 changed files with 30 additions and 35 deletions

View File

@ -289,14 +289,14 @@ err:
return ret;
}
BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, CRYPTO_MUTEX *lock,
int BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, CRYPTO_MUTEX *lock,
const BIGNUM *mod, BN_CTX *bn_ctx) {
CRYPTO_MUTEX_lock_read(lock);
BN_MONT_CTX *ctx = *pmont;
CRYPTO_MUTEX_unlock(lock);
if (ctx) {
return ctx;
return 1;
}
CRYPTO_MUTEX_lock_write(lock);
@ -318,7 +318,7 @@ BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, CRYPTO_MUTEX *lock,
out:
CRYPTO_MUTEX_unlock(lock);
return ctx;
return ctx != NULL;
}
int BN_to_montgomery(BIGNUM *ret, const BIGNUM *a, const BN_MONT_CTX *mont,

View File

@ -236,7 +236,6 @@ int DH_generate_key(DH *dh) {
int generate_new_key = 0;
unsigned l;
BN_CTX *ctx = NULL;
BN_MONT_CTX *mont = NULL;
BIGNUM *pub_key = NULL, *priv_key = NULL;
BIGNUM local_priv;
@ -269,9 +268,8 @@ int DH_generate_key(DH *dh) {
pub_key = dh->pub_key;
}
mont = BN_MONT_CTX_set_locked(&dh->method_mont_p, &dh->method_mont_p_lock,
dh->p, ctx);
if (!mont) {
if (!BN_MONT_CTX_set_locked(&dh->method_mont_p, &dh->method_mont_p_lock,
dh->p, ctx)) {
goto err;
}
@ -293,7 +291,8 @@ int DH_generate_key(DH *dh) {
}
BN_with_flags(&local_priv, priv_key, BN_FLG_CONSTTIME);
if (!BN_mod_exp_mont(pub_key, dh->g, &local_priv, dh->p, ctx, mont)) {
if (!BN_mod_exp_mont(pub_key, dh->g, &local_priv, dh->p, ctx,
dh->method_mont_p)) {
goto err;
}
@ -318,7 +317,6 @@ err:
int DH_compute_key(unsigned char *out, const BIGNUM *peers_key, DH *dh) {
BN_CTX *ctx = NULL;
BN_MONT_CTX *mont = NULL;
BIGNUM *shared_key;
int ret = -1;
int check_result;
@ -344,9 +342,8 @@ int DH_compute_key(unsigned char *out, const BIGNUM *peers_key, DH *dh) {
goto err;
}
mont = BN_MONT_CTX_set_locked(&dh->method_mont_p, &dh->method_mont_p_lock,
dh->p, ctx);
if (!mont) {
if (!BN_MONT_CTX_set_locked(&dh->method_mont_p, &dh->method_mont_p_lock,
dh->p, ctx)) {
goto err;
}
@ -357,7 +354,7 @@ int DH_compute_key(unsigned char *out, const BIGNUM *peers_key, DH *dh) {
BN_with_flags(&local_priv, dh->priv_key, BN_FLG_CONSTTIME);
if (!BN_mod_exp_mont(shared_key, peers_key, &local_priv, dh->p, ctx,
mont)) {
dh->method_mont_p)) {
OPENSSL_PUT_ERROR(DH, ERR_R_BN_LIB);
goto err;
}

View File

@ -591,7 +591,6 @@ int DSA_do_check_signature(int *out_valid, const uint8_t *digest,
size_t digest_len, DSA_SIG *sig, const DSA *dsa) {
BN_CTX *ctx;
BIGNUM u1, u2, t1;
BN_MONT_CTX *mont = NULL;
int ret = 0;
unsigned i;
@ -662,15 +661,14 @@ int DSA_do_check_signature(int *out_valid, const uint8_t *digest,
goto err;
}
mont = BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p,
(CRYPTO_MUTEX *)&dsa->method_mont_p_lock,
dsa->p, ctx);
if (!mont) {
if (!BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p,
(CRYPTO_MUTEX *)&dsa->method_mont_p_lock, dsa->p,
ctx)) {
goto err;
}
if (!BN_mod_exp2_mont(&t1, dsa->g, &u1, dsa->pub_key, &u2, dsa->p, ctx,
mont)) {
dsa->method_mont_p)) {
goto err;
}
@ -823,9 +821,9 @@ int DSA_sign_setup(const DSA *dsa, BN_CTX *ctx_in, BIGNUM **out_kinv,
BN_set_flags(&k, BN_FLG_CONSTTIME);
if (BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p,
if (!BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p,
(CRYPTO_MUTEX *)&dsa->method_mont_p_lock, dsa->p,
ctx) == NULL) {
ctx)) {
goto err;
}

View File

@ -171,7 +171,7 @@ int rsa_default_encrypt(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
goto err;
}
if (BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx) == NULL ||
if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx) ||
!BN_mod_exp_mont(result, f, rsa->e, rsa->n, ctx, rsa->mont_n)) {
goto err;
}
@ -487,7 +487,7 @@ int RSA_verify_raw(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
goto err;
}
if (BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx) == NULL ||
if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx) ||
!BN_mod_exp_mont(result, f, rsa->e, rsa->n, ctx, rsa->mont_n)) {
goto err;
}
@ -557,7 +557,7 @@ int rsa_default_private_transform(RSA *rsa, uint8_t *out, const uint8_t *in,
}
if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
if (BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx) == NULL) {
if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
goto err;
}
@ -585,7 +585,7 @@ int rsa_default_private_transform(RSA *rsa, uint8_t *out, const uint8_t *in,
d = &local_d;
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
if (BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx) == NULL ||
if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx) ||
!BN_mod_exp_mont_consttime(result, f, d, rsa->n, ctx, rsa->mont_n)) {
goto err;
}
@ -662,13 +662,13 @@ static int mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) {
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) == NULL ||
BN_MONT_CTX_set_locked(&rsa->mont_q, &rsa->lock, q, ctx) == NULL) {
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) == NULL) {
if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx)) {
goto err;
}
@ -756,7 +756,7 @@ static int mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) {
goto err;
}
if (BN_MONT_CTX_set_locked(&ap->mont, &rsa->lock, prime, ctx) == NULL ||
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;
}

View File

@ -749,10 +749,10 @@ OPENSSL_EXPORT int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod,
/* BN_MONT_CTX_set_locked takes |lock| and checks whether |*pmont| is NULL. If
* so, it creates a new |BN_MONT_CTX| and sets the modulus for it to |mod|. It
* then stores it as |*pmont| and returns it, or NULL on error.
* then stores it as |*pmont|. It returns one on success and zero on error.
*
* If |*pmont| is already non-NULL then the existing value is returned. */
BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, CRYPTO_MUTEX *lock,
* If |*pmont| is already non-NULL then it does nothing and returns one. */
int BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, CRYPTO_MUTEX *lock,
const BIGNUM *mod, BN_CTX *bn_ctx);
/* BN_to_montgomery sets |ret| equal to |a| in the Montgomery domain. It