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Lock globalRNGMutex in BN_rand, ECDH, EC25519 and AddSession #11048

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Lock globalRNGMutex in BN_rand, ECDH, EC25519 and AddSession #11048

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22 changes: 20 additions & 2 deletions src/pk.c
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Original file line number Diff line number Diff line change
Expand Up @@ -5187,6 +5187,9 @@ int wolfSSL_EC25519_shared_key(unsigned char *shared, unsigned int *sharedSz,
int res = 1;
curve25519_key privkey;
curve25519_key pubkey;
#ifdef WOLFSSL_CURVE25519_BLINDING
WC_RNG* rng = NULL;
#endif

WOLFSSL_ENTER("wolfSSL_EC25519_shared_key");

Expand All @@ -5206,8 +5209,13 @@ int wolfSSL_EC25519_shared_key(unsigned char *shared, unsigned int *sharedSz,
}
if (res) {
#ifdef WOLFSSL_CURVE25519_BLINDING
/* An RNG is needed. */
if (wc_curve25519_set_rng(&privkey, wolfssl_make_global_rng()) != 0) {
/* An RNG is needed for blinding. */
rng = wolfssl_make_global_rng();
if (rng == NULL) {
WOLFSSL_MSG("Failed to use global RNG.");
res = 0;
}
else if (wc_curve25519_set_rng(&privkey, rng) != 0) {
res = 0;
}
else
Expand Down Expand Up @@ -5235,6 +5243,13 @@ int wolfSSL_EC25519_shared_key(unsigned char *shared, unsigned int *sharedSz,
res = 0;
}
}
#ifdef WOLFSSL_CURVE25519_BLINDING
/* Global RNG is shared, lock it while blinding uses it. */
if (res && (wc_LockMutex(&globalRNGMutex) != 0)) {
WOLFSSL_MSG("Bad Lock Mutex rng");
res = 0;
}
#endif
if (res) {
/* Compute shared secret. */
ret = wc_curve25519_shared_secret_ex(&privkey, &pubkey, shared,
Expand All @@ -5243,6 +5258,9 @@ int wolfSSL_EC25519_shared_key(unsigned char *shared, unsigned int *sharedSz,
WOLFSSL_MSG("wc_curve25519_shared_secret_ex failed");
res = 0;
}
#ifdef WOLFSSL_CURVE25519_BLINDING
wc_UnLockMutex(&globalRNGMutex);
#endif
}

wc_curve25519_free(&pubkey);
Expand Down
41 changes: 28 additions & 13 deletions src/pk_ec.c
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Original file line number Diff line number Diff line change
Expand Up @@ -5489,6 +5489,7 @@ int wolfSSL_ECDH_compute_key(void *out, size_t outLen,
ecc_key* key = NULL;
#if defined(ECC_TIMING_RESISTANT) && !defined(HAVE_SELFTEST) && \
(!defined(HAVE_FIPS) || FIPS_VERSION_GE(5,0))
WC_RNG* rng = NULL;
int setGlobalRNG = 0;
#endif

Expand Down Expand Up @@ -5524,30 +5525,44 @@ int wolfSSL_ECDH_compute_key(void *out, size_t outLen,

#if defined(ECC_TIMING_RESISTANT) && !defined(HAVE_SELFTEST) && \
(!defined(HAVE_FIPS) || FIPS_VERSION_GE(5,0))
/* An RNG is needed. */
/* An RNG is needed. Hold the global lock across use of key->rng. */
if (key->rng == NULL) {
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key->rng = wolfssl_make_global_rng();
/* RNG set and needs to be unset. */
setGlobalRNG = 1;
rng = wolfssl_make_global_rng();
if (rng == NULL) {
WOLFSSL_MSG("Failed to use global RNG.");
err = 1;
}
else if (wc_LockMutex(&globalRNGMutex) != 0) {
WOLFSSL_MSG("Bad Lock Mutex rng");
err = 1;
}
else {
key->rng = rng;
/* RNG set and needs to be unset. */
setGlobalRNG = 1;
}
}
#endif

PRIVATE_KEY_UNLOCK();
/* Create secret using wolfSSL. */
ret = wc_ecc_shared_secret_ex(key, (ecc_point*)pubKey->internal,
(byte *)out, &len);
PRIVATE_KEY_LOCK();
if (ret != MP_OKAY) {
WOLFSSL_MSG("wc_ecc_shared_secret failed");
err = 1;
if (!err) {
PRIVATE_KEY_UNLOCK();
/* Create secret using wolfSSL. */
ret = wc_ecc_shared_secret_ex(key, (ecc_point*)pubKey->internal,
(byte *)out, &len);
PRIVATE_KEY_LOCK();
if (ret != MP_OKAY) {
WOLFSSL_MSG("wc_ecc_shared_secret failed");
err = 1;
}
}
}

#if defined(ECC_TIMING_RESISTANT) && !defined(HAVE_SELFTEST) && \
(!defined(HAVE_FIPS) || FIPS_VERSION_GE(5,0))
/* Remove global from key. */
/* Remove global from key and release the lock taken when setting it. */
if (setGlobalRNG) {
key->rng = NULL;
wc_UnLockMutex(&globalRNGMutex);
}
#endif

Expand Down
15 changes: 12 additions & 3 deletions src/ssl_bn.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2146,11 +2146,20 @@ int wolfSSL_BN_rand(WOLFSSL_BIGNUM* bn, int bits, int top, int bottom)
WOLFSSL_MSG("Failed to allocate buffer.");
ret = 0;
}
/* Generate bytes to cover bits. */
if ((ret == 1) && wc_RNG_GenerateBlock(rng, buff, len) != 0) {
WOLFSSL_MSG("wc_RNG_GenerateBlock failed");
/* Global RNG is shared, lock it while generating. */
if ((ret == 1) && (wc_LockMutex(&globalRNGMutex) != 0)) {
WOLFSSL_MSG("Bad Lock Mutex rng");
ret = 0;
}

/* Generate bytes to cover bits. */
if (ret == 1) {
if (wc_RNG_GenerateBlock(rng, buff, len) != 0) {
WOLFSSL_MSG("wc_RNG_GenerateBlock failed");
ret = 0;
}
wc_UnLockMutex(&globalRNGMutex);
}
/* Read bytes in to big number. */
if ((ret == 1) && mp_read_unsigned_bin((mp_int*)bn->internal, buff, len)
!= MP_OKAY) {
Expand Down
18 changes: 16 additions & 2 deletions src/ssl_sess.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2162,15 +2162,29 @@ void AddSession(WOLFSSL* ssl)
* this point, it won't on resumption. */
if (idSz == 0 && ssl->options.side == WOLFSSL_CLIENT_END) {
WC_RNG* rng = NULL;
int genRet;
#if defined(HAVE_GLOBAL_RNG) && defined(OPENSSL_EXTRA)
int rngLocked = 0;
#endif
if (ssl->rng != NULL)
rng = ssl->rng;
#if defined(HAVE_GLOBAL_RNG) && defined(OPENSSL_EXTRA)
else if (initGlobalRNG == 1 || wolfSSL_RAND_Init() == WOLFSSL_SUCCESS) {
/* Global RNG is shared, lock it while generating. */
if (wc_LockMutex(&globalRNGMutex) != 0) {
WOLFSSL_MSG("Bad Lock Mutex rng");
return;
}
rng = &globalRNG;
rngLocked = 1;
}
#endif
if (wc_RNG_GenerateBlock(rng, ssl->session->altSessionID,
ID_LEN) != 0)
genRet = wc_RNG_GenerateBlock(rng, ssl->session->altSessionID, ID_LEN);
#if defined(HAVE_GLOBAL_RNG) && defined(OPENSSL_EXTRA)
if (rngLocked)
wc_UnLockMutex(&globalRNGMutex);
#endif
if (genRet != 0)
return;
ssl->session->haveAltSessionID = 1;
id = ssl->session->altSessionID;
Expand Down
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