* |randomness| argument). This will immediately reseed the <master> DRBG.
* The <public> and <private> DRBG will detect this on their next generate
* call and reseed, pulling randomness from <master>.
+ *
+ * LOCKING
+ *
+ * The three shared DRBGs are intended to be used concurrently, so they
+ * support locking. The RAND methods take the locks automatically, so using
+ * the RAND api (in particular RAND_bytes() and RAND_priv_bytes()) is
+ * thread-safe. Note however that accessing the shared DRBGs directly via
+ * the RAND_DRBG interface is *not* thread-safe.
+ *
+ * All other DRBG instances don't support locking, because they are
+ * intendended to be used by a single thread. Instead of accessing a single
+ * DRBG instance concurrently from different threads, it is recommended to
+ * instantiate a separate DRBG instance per thread. Using the same shared
+ * DRBG (preferrably the public DRBG) as parent of DRBG instances on
+ * different threads is safe.
*/
static CRYPTO_ONCE rand_drbg_init = CRYPTO_ONCE_STATIC_INIT;
+static unsigned int master_reseed_interval = MASTER_RESEED_INTERVAL;
+static unsigned int slave_reseed_interval = SLAVE_RESEED_INTERVAL;
+
+static time_t master_reseed_time_interval = MASTER_RESEED_TIME_INTERVAL;
+static time_t slave_reseed_time_interval = SLAVE_RESEED_TIME_INTERVAL;
+
static RAND_DRBG *drbg_setup(RAND_DRBG *parent);
-static void drbg_cleanup(RAND_DRBG *drbg);
+
+static RAND_DRBG *rand_drbg_new(int secure,
+ int type,
+ unsigned int flags,
+ RAND_DRBG *parent);
/*
* Set/initialize |drbg| to be of type |nid|, with optional |flags|.
}
/*
- * Allocate memory and initialize a new DRBG. The |parent|, if not
- * NULL, will be used to auto-seed this RAND_DRBG as needed.
+ * Allocate memory and initialize a new DRBG. The DRBG is allocated on
+ * the secure heap if |secure| is nonzero and the secure heap is enabled.
+ * The |parent|, if not NULL, will be used as random source for reseeding.
*
* Returns a pointer to the new DRBG instance on success, NULL on failure.
*/
-RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent)
+static RAND_DRBG *rand_drbg_new(int secure,
+ int type,
+ unsigned int flags,
+ RAND_DRBG *parent)
{
- RAND_DRBG *drbg = OPENSSL_zalloc(sizeof(*drbg));
+ RAND_DRBG *drbg = secure ?
+ OPENSSL_secure_zalloc(sizeof(*drbg)) : OPENSSL_zalloc(sizeof(*drbg));
if (drbg == NULL) {
RANDerr(RAND_F_RAND_DRBG_NEW, ERR_R_MALLOC_FAILURE);
goto err;
}
+
+ drbg->secure = secure && CRYPTO_secure_allocated(drbg);
drbg->fork_count = rand_fork_count;
drbg->parent = parent;
+
+ if (parent == NULL) {
+ drbg->reseed_interval = master_reseed_interval;
+ drbg->reseed_time_interval = master_reseed_time_interval;
+ } else {
+ drbg->reseed_interval = slave_reseed_interval;
+ drbg->reseed_time_interval = slave_reseed_time_interval;
+ }
+
if (RAND_DRBG_set(drbg, type, flags) == 0)
goto err;
+ if (parent != NULL && drbg->strength > parent->strength) {
+ /*
+ * We currently don't support the algorithm from NIST SP 800-90C
+ * 10.1.2 to use a weaker DRBG as source
+ */
+ RANDerr(RAND_F_RAND_DRBG_NEW, RAND_R_PARENT_STRENGTH_TOO_WEAK);
+ goto err;
+ }
+
if (!RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy,
rand_drbg_cleanup_entropy,
NULL, NULL))
return drbg;
err:
- OPENSSL_free(drbg);
+ if (drbg->secure)
+ OPENSSL_secure_free(drbg);
+ else
+ OPENSSL_free(drbg);
+
return NULL;
}
+RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent)
+{
+ return rand_drbg_new(0, type, flags, parent);
+}
+
+RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent)
+{
+ return rand_drbg_new(1, type, flags, parent);
+}
+
/*
* Uninstantiate |drbg| and free all memory.
*/
if (drbg->meth != NULL)
drbg->meth->uninstantiate(drbg);
+ CRYPTO_THREAD_lock_free(drbg->lock);
CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data);
- OPENSSL_clear_free(drbg, sizeof(*drbg));
+
+ if (drbg->secure)
+ OPENSSL_secure_clear_free(drbg, sizeof(*drbg));
+ else
+ OPENSSL_clear_free(drbg, sizeof(*drbg));
}
/*
RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED);
drbg->state = DRBG_ERROR;
}
- RAND_POOL_free(drbg->pool);
+ rand_pool_free(drbg->pool);
drbg->pool = NULL;
}
if (drbg->state == DRBG_READY)
if (drbg->pool != NULL) {
RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
- RAND_POOL_free(drbg->pool);
+ rand_pool_free(drbg->pool);
drbg->pool = NULL;
}
}
/* will be picked up by the rand_drbg_get_entropy() callback */
- drbg->pool = RAND_POOL_new(entropy, len, len);
+ drbg->pool = rand_pool_new(entropy, len, len);
if (drbg->pool == NULL)
return 0;
- RAND_POOL_add(drbg->pool, buffer, len, entropy);
+ rand_pool_add(drbg->pool, buffer, len, entropy);
} else {
if (drbg->max_adinlen < len) {
RANDerr(RAND_F_RAND_DRBG_RESTART,
if (drbg->pool != NULL) {
drbg->state = DRBG_ERROR;
RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
- RAND_POOL_free(drbg->pool);
+ rand_pool_free(drbg->pool);
drbg->pool = NULL;
return 0;
}
{
unsigned char *additional = NULL;
size_t additional_len;
+ size_t chunk;
size_t ret;
additional_len = rand_drbg_get_additional_data(&additional, drbg->max_adinlen);
- ret = RAND_DRBG_generate(drbg, out, outlen, 0, additional, additional_len);
+
+ for ( ; outlen > 0; outlen -= chunk, out += chunk) {
+ chunk = outlen;
+ if (chunk > drbg->max_request)
+ chunk = drbg->max_request;
+ ret = RAND_DRBG_generate(drbg, out, chunk, 0, additional, additional_len);
+ if (!ret)
+ goto err;
+ }
+ ret = 1;
+
+err:
if (additional_len != 0)
OPENSSL_secure_clear_free(additional, additional_len);
return 1;
}
+/*
+ * Set the default values for reseed (time) intervals of new DRBG instances
+ *
+ * The default values can be set independently for master DRBG instances
+ * (without a parent) and slave DRBG instances (with parent).
+ *
+ * Returns 1 on success, 0 on failure.
+ */
+
+int RAND_DRBG_set_reseed_defaults(
+ unsigned int _master_reseed_interval,
+ unsigned int _slave_reseed_interval,
+ time_t _master_reseed_time_interval,
+ time_t _slave_reseed_time_interval
+ )
+{
+ if (_master_reseed_interval > MAX_RESEED_INTERVAL
+ || _slave_reseed_interval > MAX_RESEED_INTERVAL)
+ return 0;
+
+ if (_master_reseed_time_interval > MAX_RESEED_TIME_INTERVAL
+ || _slave_reseed_time_interval > MAX_RESEED_TIME_INTERVAL)
+ return 0;
+
+ master_reseed_interval = _master_reseed_interval;
+ slave_reseed_interval = _slave_reseed_interval;
+
+ master_reseed_time_interval = _master_reseed_time_interval;
+ slave_reseed_time_interval = _slave_reseed_time_interval;
+
+ return 1;
+}
+
+/*
+ * Locks the given drbg. Locking a drbg which does not have locking
+ * enabled is considered a successful no-op.
+ *
+ * Returns 1 on success, 0 on failure.
+ */
+int rand_drbg_lock(RAND_DRBG *drbg)
+{
+ if (drbg->lock != NULL)
+ return CRYPTO_THREAD_write_lock(drbg->lock);
+
+ return 1;
+}
+
+/*
+ * Unlocks the given drbg. Unlocking a drbg which does not have locking
+ * enabled is considered a successful no-op.
+ *
+ * Returns 1 on success, 0 on failure.
+ */
+int rand_drbg_unlock(RAND_DRBG *drbg)
+{
+ if (drbg->lock != NULL)
+ return CRYPTO_THREAD_unlock(drbg->lock);
+
+ return 1;
+}
+
+/*
+ * Enables locking for the given drbg
+ *
+ * Locking can only be enabled if the random generator
+ * is in the uninitialized state.
+ *
+ * Returns 1 on success, 0 on failure.
+ */
+int rand_drbg_enable_locking(RAND_DRBG *drbg)
+{
+ if (drbg->state != DRBG_UNINITIALISED) {
+ RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
+ RAND_R_DRBG_ALREADY_INITIALIZED);
+ return 0;
+ }
+
+ if (drbg->lock == NULL) {
+ if (drbg->parent != NULL && drbg->parent->lock == NULL) {
+ RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
+ RAND_R_PARENT_LOCKING_NOT_ENABLED);
+ return 0;
+ }
+
+ drbg->lock = CRYPTO_THREAD_lock_new();
+ if (drbg->lock == NULL) {
+ RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
+ RAND_R_FAILED_TO_CREATE_LOCK);
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
/*
* Get and set the EXDATA
*/
{
RAND_DRBG *drbg;
- drbg = OPENSSL_secure_zalloc(sizeof(RAND_DRBG));
+ drbg = RAND_DRBG_secure_new(RAND_DRBG_NID, 0, parent);
if (drbg == NULL)
return NULL;
- drbg->lock = CRYPTO_THREAD_lock_new();
- if (drbg->lock == NULL) {
- RANDerr(RAND_F_DRBG_SETUP, RAND_R_FAILED_TO_CREATE_LOCK);
- goto err;
- }
-
- if (RAND_DRBG_set(drbg,
- RAND_DRBG_NID, RAND_DRBG_FLAG_CTR_USE_DF) != 1)
- goto err;
- if (RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy,
- rand_drbg_cleanup_entropy, NULL, NULL) != 1)
+ if (rand_drbg_enable_locking(drbg) == 0)
goto err;
- if (parent == NULL) {
- drbg->reseed_interval = MASTER_RESEED_INTERVAL;
- drbg->reseed_time_interval = MASTER_RESEED_TIME_INTERVAL;
- } else {
- drbg->parent = parent;
- drbg->reseed_interval = SLAVE_RESEED_INTERVAL;
- drbg->reseed_time_interval = SLAVE_RESEED_TIME_INTERVAL;
- }
-
/* enable seed propagation */
drbg->reseed_counter = 1;
return drbg;
err:
- drbg_cleanup(drbg);
+ RAND_DRBG_free(drbg);
return NULL;
}
return 1;
}
-/* Cleans up the given global DRBG */
-static void drbg_cleanup(RAND_DRBG *drbg)
-{
- if (drbg != NULL) {
- RAND_DRBG_uninstantiate(drbg);
- CRYPTO_THREAD_lock_free(drbg->lock);
- OPENSSL_secure_clear_free(drbg, sizeof(RAND_DRBG));
- }
-}
-
/* Clean up the global DRBGs before exit */
void rand_drbg_cleanup_int(void)
{
- drbg_cleanup(drbg_private);
- drbg_cleanup(drbg_public);
- drbg_cleanup(drbg_master);
+ RAND_DRBG_free(drbg_private);
+ RAND_DRBG_free(drbg_public);
+ RAND_DRBG_free(drbg_master);
drbg_private = drbg_public = drbg_master = NULL;
}
/* Implements the default OpenSSL RAND_bytes() method */
static int drbg_bytes(unsigned char *out, int count)
{
- int ret = 0;
- size_t chunk;
+ int ret;
RAND_DRBG *drbg = RAND_DRBG_get0_public();
if (drbg == NULL)
return 0;
- CRYPTO_THREAD_write_lock(drbg->lock);
- if (drbg->state == DRBG_UNINITIALISED)
- goto err;
-
- for ( ; count > 0; count -= chunk, out += chunk) {
- chunk = count;
- if (chunk > drbg->max_request)
- chunk = drbg->max_request;
- ret = RAND_DRBG_generate(drbg, out, chunk, 0, NULL, 0);
- if (!ret)
- goto err;
- }
- ret = 1;
+ rand_drbg_lock(drbg);
+ ret = RAND_DRBG_bytes(drbg, out, count);
+ rand_drbg_unlock(drbg);
-err:
- CRYPTO_THREAD_unlock(drbg->lock);
return ret;
}
return 0;
}
- CRYPTO_THREAD_write_lock(drbg->lock);
+ rand_drbg_lock(drbg);
ret = rand_drbg_restart(drbg, buf,
(size_t)(unsigned int)num,
(size_t)(8*randomness));
- CRYPTO_THREAD_unlock(drbg->lock);
+ rand_drbg_unlock(drbg);
return ret;
}
if (drbg == NULL)
return 0;
- CRYPTO_THREAD_write_lock(drbg->lock);
+ rand_drbg_lock(drbg);
ret = drbg->state == DRBG_READY ? 1 : 0;
- CRYPTO_THREAD_unlock(drbg->lock);
+ rand_drbg_unlock(drbg);
return ret;
}