#include "internal/cryptlib_int.h"
/*
- * Support framework for NIST SP 800-90A DRBG, AES-CTR mode.
- * The RAND_DRBG is OpenSSL's pointer to an instance of the DRBG.
+ * Support framework for NIST SP 800-90A DRBG
+ *
+ * See manual page RAND_DRBG(7) for a general overview.
*
* The OpenSSL model is to have new and free functions, and that new
* does all initialization. That is not the NIST model, which has
*/
/*
- * THE THREE SHARED DRBGs
- *
- * There are three shared DRBGs (master, public and private), which are
- * accessed concurrently by all threads.
+ * The three shared DRBG instances
*
- * THE MASTER DRBG
+ * There are three shared DRBG instances: <master>, <public>, and <private>.
+ */
+
+/*
+ * The <master> DRBG
*
* Not used directly by the application, only for reseeding the two other
* DRBGs. It reseeds itself by pulling either randomness from os entropy
- * sources or by consuming randomnes which was added by RAND_add()
- */
-static RAND_DRBG *drbg_master;
-/*+
- * DRBG HIERARCHY
- *
- * In addition there are DRBGs, which are not shared, but used only by a
- * single thread at every time, for example the DRBGs which are owned by
- * an SSL context. All DRBGs are organized in a hierarchical fashion
- * with the <master> DRBG as root.
+ * sources or by consuming randomness which was added by RAND_add().
*
- * This gives the following overall picture:
- *
- * <os entropy sources>
- * |
- * RAND_add() ==> <master> \
- * / \ | shared DRBGs (with locking)
- * <public> <private> /
- * |
- * <ssl> owned by an SSL context
- *
- * AUTOMATIC RESEEDING
- *
- * Before satisfying a generate request, a DRBG reseeds itself automatically,
- * if one of the following two conditions holds:
- *
- * - the number of generate requests since the last reseeding exceeds a
- * certain threshold, the so called |reseed_interval|. This behaviour
- * can be disabled by setting the |reseed_interval| to 0.
- *
- * - the time elapsed since the last reseeding exceeds a certain time
- * interval, the so called |reseed_time_interval|. This behaviour
- * can be disabled by setting the |reseed_time_interval| to 0.
- *
- * MANUAL RESEEDING
+ * The <master> DRBG is a global instance which is accessed concurrently by
+ * all threads. The necessary locking is managed automatically by its child
+ * DRBG instances during reseeding.
+ */
+static RAND_DRBG *master_drbg;
+/*
+ * The <public> DRBG
*
- * For the three shared DRBGs (and only for these) there is another way to
- * reseed them manually by calling RAND_seed() (or RAND_add() with a positive
- * |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>.
+ * Used by default for generating random bytes using RAND_bytes().
*
- * LOCKING
+ * The <public> DRBG is thread-local, i.e., there is one instance per thread.
+ */
+static CRYPTO_THREAD_LOCAL public_drbg;
+/*
+ * The <private> DRBG
*
- * 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.
+ * Used by default for generating private keys using RAND_priv_bytes()
*
- * 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.
+ * The <private> DRBG is thread-local, i.e., there is one instance per thread.
*/
+static CRYPTO_THREAD_LOCAL private_drbg;
+
/* NIST SP 800-90A DRBG recommends the use of a personalization string. */
static const char ossl_pers_string[] = "OpenSSL NIST SP 800-90A DRBG";
static CRYPTO_ONCE rand_drbg_init = CRYPTO_ONCE_STATIC_INIT;
-static CRYPTO_THREAD_LOCAL private_drbg_thread_local_key;
-static CRYPTO_THREAD_LOCAL public_drbg_thread_local_key;
static time_t master_reseed_time_interval = MASTER_RESEED_TIME_INTERVAL;
static time_t slave_reseed_time_interval = SLAVE_RESEED_TIME_INTERVAL;
+/* A logical OR of all used DRBG flag bits (currently there is only one) */
+static const unsigned int rand_drbg_used_flags =
+ RAND_DRBG_FLAG_CTR_NO_DF;
+
static RAND_DRBG *drbg_setup(RAND_DRBG *parent);
static RAND_DRBG *rand_drbg_new(int secure,
flags = rand_drbg_flags;
}
+ /* If set is called multiple times - clear the old one */
+ if (drbg->type != 0 && (type != drbg->type || flags != drbg->flags)) {
+ drbg->meth->uninstantiate(drbg);
+ rand_pool_free(drbg->adin_pool);
+ drbg->adin_pool = NULL;
+ }
+
drbg->state = DRBG_UNINITIALISED;
drbg->flags = flags;
drbg->type = type;
switch (type) {
default:
+ drbg->type = 0;
+ drbg->flags = 0;
+ drbg->meth = NULL;
RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE);
return 0;
case 0:
/* Uninitialized; that's okay. */
+ drbg->meth = NULL;
return 1;
case NID_aes_128_ctr:
case NID_aes_192_ctr:
break;
}
- if (ret == 0)
+ if (ret == 0) {
+ drbg->state = DRBG_ERROR;
RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG);
+ }
return ret;
}
break;
}
- if ((flags & ~RAND_DRBG_USED_FLAGS) != 0) {
+ if ((flags & ~rand_drbg_used_flags) != 0) {
RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_FLAGS);
return 0;
}
drbg->parent = parent;
if (parent == NULL) {
+ drbg->get_entropy = rand_drbg_get_entropy;
+ drbg->cleanup_entropy = rand_drbg_cleanup_entropy;
+#ifndef RAND_DRBG_GET_RANDOM_NONCE
+ drbg->get_nonce = rand_drbg_get_nonce;
+ drbg->cleanup_nonce = rand_drbg_cleanup_nonce;
+#endif
+
drbg->reseed_interval = master_reseed_interval;
drbg->reseed_time_interval = master_reseed_time_interval;
} else {
+ drbg->get_entropy = rand_drbg_get_entropy;
+ drbg->cleanup_entropy = rand_drbg_cleanup_entropy;
+ /*
+ * Do not provide nonce callbacks, the child DRBGs will
+ * obtain their nonce using random bits from the parent.
+ */
+
drbg->reseed_interval = slave_reseed_interval;
drbg->reseed_time_interval = slave_reseed_time_interval;
}
rand_drbg_unlock(parent);
}
- if (!RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy,
- rand_drbg_cleanup_entropy,
- NULL, NULL))
- goto err;
-
return drbg;
-err:
- if (drbg->secure)
- OPENSSL_secure_free(drbg);
- else
- OPENSSL_free(drbg);
+ err:
+ RAND_DRBG_free(drbg);
return NULL;
}
if (drbg->meth != NULL)
drbg->meth->uninstantiate(drbg);
+ rand_pool_free(drbg->adin_pool);
CRYPTO_THREAD_lock_free(drbg->lock);
CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data);
{
unsigned char *nonce = NULL, *entropy = NULL;
size_t noncelen = 0, entropylen = 0;
+ size_t min_entropy = drbg->strength;
+ size_t min_entropylen = drbg->min_entropylen;
+ size_t max_entropylen = drbg->max_entropylen;
if (perslen > drbg->max_perslen) {
RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
goto end;
}
- if (drbg->meth == NULL)
- {
+ if (drbg->meth == NULL) {
RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
goto end;
}
drbg->state = DRBG_ERROR;
+
+ /*
+ * NIST SP800-90Ar1 section 9.1 says you can combine getting the entropy
+ * and nonce in 1 call by increasing the entropy with 50% and increasing
+ * the minimum length to accomadate the length of the nonce.
+ * We do this in case a nonce is require and get_nonce is NULL.
+ */
+ if (drbg->min_noncelen > 0 && drbg->get_nonce == NULL) {
+ min_entropy += drbg->strength / 2;
+ min_entropylen += drbg->min_noncelen;
+ max_entropylen += drbg->max_noncelen;
+ }
+
+ drbg->reseed_next_counter = tsan_load(&drbg->reseed_prop_counter);
+ if (drbg->reseed_next_counter) {
+ drbg->reseed_next_counter++;
+ if(!drbg->reseed_next_counter)
+ drbg->reseed_next_counter = 1;
+ }
+
if (drbg->get_entropy != NULL)
- entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength,
- drbg->min_entropylen,
- drbg->max_entropylen, 0);
- if (entropylen < drbg->min_entropylen
- || entropylen > drbg->max_entropylen) {
+ entropylen = drbg->get_entropy(drbg, &entropy, min_entropy,
+ min_entropylen, max_entropylen, 0);
+ if (entropylen < min_entropylen
+ || entropylen > max_entropylen) {
RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_ENTROPY);
goto end;
}
- if (drbg->max_noncelen > 0 && drbg->get_nonce != NULL) {
+ if (drbg->min_noncelen > 0 && drbg->get_nonce != NULL) {
noncelen = drbg->get_nonce(drbg, &nonce, drbg->strength / 2,
drbg->min_noncelen, drbg->max_noncelen);
if (noncelen < drbg->min_noncelen || noncelen > drbg->max_noncelen) {
- RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
- RAND_R_ERROR_RETRIEVING_NONCE);
+ RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_NONCE);
goto end;
}
}
}
drbg->state = DRBG_READY;
- drbg->generate_counter = 0;
+ drbg->reseed_gen_counter = 1;
drbg->reseed_time = time(NULL);
- if (drbg->reseed_counter > 0) {
- if (drbg->parent == NULL)
- drbg->reseed_counter++;
- else
- drbg->reseed_counter = drbg->parent->reseed_counter;
- }
+ tsan_store(&drbg->reseed_prop_counter, drbg->reseed_next_counter);
-end:
+ end:
if (entropy != NULL && drbg->cleanup_entropy != NULL)
drbg->cleanup_entropy(drbg, entropy, entropylen);
- if (nonce != NULL && drbg->cleanup_nonce!= NULL )
+ if (nonce != NULL && drbg->cleanup_nonce != NULL)
drbg->cleanup_nonce(drbg, nonce, noncelen);
- if (drbg->pool != NULL) {
- if (drbg->state == DRBG_READY) {
- RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
- RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED);
- drbg->state = DRBG_ERROR;
- }
- rand_pool_free(drbg->pool);
- drbg->pool = NULL;
- }
if (drbg->state == DRBG_READY)
return 1;
return 0;
*/
int RAND_DRBG_uninstantiate(RAND_DRBG *drbg)
{
- if (drbg->meth == NULL)
- {
+ if (drbg->meth == NULL) {
+ drbg->state = DRBG_ERROR;
RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE,
RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
return 0;
return 0;
}
- if (adin == NULL)
+ if (adin == NULL) {
adinlen = 0;
- else if (adinlen > drbg->max_adinlen) {
+ } else if (adinlen > drbg->max_adinlen) {
RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ADDITIONAL_INPUT_TOO_LONG);
return 0;
}
drbg->state = DRBG_ERROR;
+
+ drbg->reseed_next_counter = tsan_load(&drbg->reseed_prop_counter);
+ if (drbg->reseed_next_counter) {
+ drbg->reseed_next_counter++;
+ if(!drbg->reseed_next_counter)
+ drbg->reseed_next_counter = 1;
+ }
+
if (drbg->get_entropy != NULL)
entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength,
drbg->min_entropylen,
drbg->max_entropylen,
prediction_resistance);
if (entropylen < drbg->min_entropylen
- || entropylen > drbg->max_entropylen) {
+ || entropylen > drbg->max_entropylen) {
RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ERROR_RETRIEVING_ENTROPY);
goto end;
}
goto end;
drbg->state = DRBG_READY;
- drbg->generate_counter = 0;
+ drbg->reseed_gen_counter = 1;
drbg->reseed_time = time(NULL);
- if (drbg->reseed_counter > 0) {
- if (drbg->parent == NULL)
- drbg->reseed_counter++;
- else
- drbg->reseed_counter = drbg->parent->reseed_counter;
- }
+ tsan_store(&drbg->reseed_prop_counter, drbg->reseed_next_counter);
-end:
+ end:
if (entropy != NULL && drbg->cleanup_entropy != NULL)
drbg->cleanup_entropy(drbg, entropy, entropylen);
if (drbg->state == DRBG_READY)
const unsigned char *adin = NULL;
size_t adinlen = 0;
- if (drbg->pool != NULL) {
+ if (drbg->seed_pool != NULL) {
RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
- rand_pool_free(drbg->pool);
- drbg->pool = NULL;
+ drbg->state = DRBG_ERROR;
+ rand_pool_free(drbg->seed_pool);
+ drbg->seed_pool = NULL;
+ return 0;
}
if (buffer != NULL) {
if (drbg->max_entropylen < len) {
RANDerr(RAND_F_RAND_DRBG_RESTART,
RAND_R_ENTROPY_INPUT_TOO_LONG);
+ drbg->state = DRBG_ERROR;
return 0;
}
if (entropy > 8 * len) {
RANDerr(RAND_F_RAND_DRBG_RESTART, RAND_R_ENTROPY_OUT_OF_RANGE);
+ drbg->state = DRBG_ERROR;
return 0;
}
/* will be picked up by the rand_drbg_get_entropy() callback */
- drbg->pool = rand_pool_new(entropy, len, len);
- if (drbg->pool == NULL)
+ drbg->seed_pool = rand_pool_attach(buffer, len, entropy);
+ if (drbg->seed_pool == NULL)
return 0;
-
- rand_pool_add(drbg->pool, buffer, len, entropy);
} else {
if (drbg->max_adinlen < len) {
RANDerr(RAND_F_RAND_DRBG_RESTART,
RAND_R_ADDITIONAL_INPUT_TOO_LONG);
+ drbg->state = DRBG_ERROR;
return 0;
}
adin = buffer;
}
}
- /* check whether a given entropy pool was cleared properly during reseed */
- if (drbg->pool != NULL) {
- drbg->state = DRBG_ERROR;
- RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
- rand_pool_free(drbg->pool);
- drbg->pool = NULL;
- return 0;
- }
+ rand_pool_free(drbg->seed_pool);
+ drbg->seed_pool = NULL;
return drbg->state == DRBG_READY;
}
}
if (drbg->reseed_interval > 0) {
- if (drbg->generate_counter >= drbg->reseed_interval)
+ if (drbg->reseed_gen_counter >= drbg->reseed_interval)
reseed_required = 1;
}
if (drbg->reseed_time_interval > 0) {
|| now - drbg->reseed_time >= drbg->reseed_time_interval)
reseed_required = 1;
}
- if (drbg->reseed_counter > 0 && drbg->parent != NULL) {
- if (drbg->reseed_counter != drbg->parent->reseed_counter)
+ if (drbg->parent != NULL) {
+ unsigned int reseed_counter = tsan_load(&drbg->reseed_prop_counter);
+ if (reseed_counter > 0
+ && tsan_load(&drbg->parent->reseed_prop_counter)
+ != reseed_counter)
reseed_required = 1;
}
return 0;
}
- drbg->generate_counter++;
+ drbg->reseed_gen_counter++;
return 1;
}
unsigned char *additional = NULL;
size_t additional_len;
size_t chunk;
- size_t ret;
+ size_t ret = 0;
+
+ if (drbg->adin_pool == NULL) {
+ if (drbg->type == 0)
+ goto err;
+ drbg->adin_pool = rand_pool_new(0, 0, drbg->max_adinlen);
+ if (drbg->adin_pool == NULL)
+ goto err;
+ }
- additional_len = rand_drbg_get_additional_data(&additional, drbg->max_adinlen);
+ additional_len = rand_drbg_get_additional_data(drbg->adin_pool,
+ &additional);
for ( ; outlen > 0; outlen -= chunk, out += chunk) {
chunk = outlen;
}
ret = 1;
-err:
- if (additional_len != 0)
- OPENSSL_secure_clear_free(additional, additional_len);
+ err:
+ if (additional != NULL)
+ rand_drbg_cleanup_additional_data(drbg->adin_pool, additional);
return ret;
}
/*
* Set the RAND_DRBG callbacks for obtaining entropy and nonce.
*
- * In the following, the signature and the semantics of the
- * get_entropy() and cleanup_entropy() callbacks are explained.
- *
- * GET_ENTROPY
- *
- * size_t get_entropy(RAND_DRBG *ctx,
- * unsigned char **pout,
- * int entropy,
- * size_t min_len, size_t max_len);
- *
- * This is a request to allocate and fill a buffer of size
- * |min_len| <= size <= |max_len| (in bytes) which contains
- * at least |entropy| bits of randomness. The buffer's address is
- * to be returned in |*pout| and the number of collected
- * randomness bytes (which may be less than the allocated size
- * of the buffer) as return value.
- *
- * If the callback fails to acquire at least |entropy| bits of
- * randomness, it shall return a buffer length of 0.
- *
- * CLEANUP_ENTROPY
+ * Setting the callbacks is allowed only if the drbg has not been
+ * initialized yet. Otherwise, the operation will fail.
*
- * void cleanup_entropy(RAND_DRBG *ctx,
- * unsigned char *out, size_t outlen);
- *
- * A request to clear and free the buffer allocated by get_entropy().
- * The values |out| and |outlen| are expected to be the random buffer's
- * address and length, as returned by the get_entropy() callback.
- *
- * GET_NONCE, CLEANUP_NONCE
- *
- * Signature and semantics of the get_nonce() and cleanup_nonce()
- * callbacks are analogous to get_entropy() and cleanup_entropy().
- * Currently, the nonce is used only for the known answer tests.
+ * Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_set_callbacks(RAND_DRBG *drbg,
RAND_DRBG_get_entropy_fn get_entropy,
RAND_DRBG_get_nonce_fn get_nonce,
RAND_DRBG_cleanup_nonce_fn cleanup_nonce)
{
- if (drbg->state != DRBG_UNINITIALISED)
+ if (drbg->state != DRBG_UNINITIALISED
+ || drbg->parent != NULL)
return 0;
drbg->get_entropy = get_entropy;
drbg->cleanup_entropy = cleanup_entropy;
goto err;
/* enable seed propagation */
- drbg->reseed_counter = 1;
+ tsan_store(&drbg->reseed_prop_counter, 1);
/*
- * Ignore instantiation error so support just-in-time instantiation.
+ * Ignore instantiation error to support just-in-time instantiation.
*
* The state of the drbg will be checked in RAND_DRBG_generate() and
* an automatic recovery is attempted.
*/
- RAND_DRBG_instantiate(drbg,
- (const unsigned char *) ossl_pers_string,
- sizeof(ossl_pers_string) - 1);
+ (void)RAND_DRBG_instantiate(drbg,
+ (const unsigned char *) ossl_pers_string,
+ sizeof(ossl_pers_string) - 1);
return drbg;
err:
*/
DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init)
{
- int ret = 1;
-
/*
* ensure that libcrypto is initialized, otherwise the
* DRBG locks are not cleaned up properly
if (!OPENSSL_init_crypto(0, NULL))
return 0;
- ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
-
- drbg_master = drbg_setup(NULL);
+ if (!CRYPTO_THREAD_init_local(&private_drbg, NULL))
+ return 0;
- ret &= CRYPTO_THREAD_init_local(&private_drbg_thread_local_key, NULL);
- ret &= CRYPTO_THREAD_init_local(&public_drbg_thread_local_key, NULL);
+ if (!CRYPTO_THREAD_init_local(&public_drbg, NULL))
+ goto err1;
- if (drbg_master == NULL || ret == 0)
- return 0;
+ master_drbg = drbg_setup(NULL);
+ if (master_drbg == NULL)
+ goto err2;
return 1;
+
+err2:
+ CRYPTO_THREAD_cleanup_local(&public_drbg);
+err1:
+ CRYPTO_THREAD_cleanup_local(&private_drbg);
+ return 0;
}
/* Clean up the global DRBGs before exit */
void rand_drbg_cleanup_int(void)
{
- RAND_DRBG_free(drbg_master);
- drbg_master = NULL;
+ if (master_drbg != NULL) {
+ RAND_DRBG_free(master_drbg);
+ master_drbg = NULL;
- CRYPTO_THREAD_cleanup_local(&private_drbg_thread_local_key);
- CRYPTO_THREAD_cleanup_local(&public_drbg_thread_local_key);
+ CRYPTO_THREAD_cleanup_local(&private_drbg);
+ CRYPTO_THREAD_cleanup_local(&public_drbg);
+ }
}
-void drbg_delete_thread_state()
+void drbg_delete_thread_state(void)
{
RAND_DRBG *drbg;
- drbg = CRYPTO_THREAD_get_local(&public_drbg_thread_local_key);
+ drbg = CRYPTO_THREAD_get_local(&public_drbg);
+ CRYPTO_THREAD_set_local(&public_drbg, NULL);
RAND_DRBG_free(drbg);
- drbg = CRYPTO_THREAD_get_local(&private_drbg_thread_local_key);
+ drbg = CRYPTO_THREAD_get_local(&private_drbg);
+ CRYPTO_THREAD_set_local(&private_drbg, NULL);
RAND_DRBG_free(drbg);
}
return ret;
}
+/*
+ * Calculates the minimum length of a full entropy buffer
+ * which is necessary to seed (i.e. instantiate) the DRBG
+ * successfully.
+ */
+size_t rand_drbg_seedlen(RAND_DRBG *drbg)
+{
+ /*
+ * If no os entropy source is available then RAND_seed(buffer, bufsize)
+ * is expected to succeed if and only if the buffer length satisfies
+ * the following requirements, which follow from the calculations
+ * in RAND_DRBG_instantiate().
+ */
+ size_t min_entropy = drbg->strength;
+ size_t min_entropylen = drbg->min_entropylen;
+
+ /*
+ * Extra entropy for the random nonce in the absence of a
+ * get_nonce callback, see comment in RAND_DRBG_instantiate().
+ */
+ if (drbg->min_noncelen > 0 && drbg->get_nonce == NULL) {
+ min_entropy += drbg->strength / 2;
+ min_entropylen += drbg->min_noncelen;
+ }
+
+ /*
+ * Convert entropy requirement from bits to bytes
+ * (dividing by 8 without rounding upwards, because
+ * all entropy requirements are divisible by 8).
+ */
+ min_entropy >>= 3;
+
+ /* Return a value that satisfies both requirements */
+ return min_entropy > min_entropylen ? min_entropy : min_entropylen;
+}
+
/* Implements the default OpenSSL RAND_add() method */
static int drbg_add(const void *buf, int num, double randomness)
{
int ret = 0;
RAND_DRBG *drbg = RAND_DRBG_get0_master();
+ size_t buflen;
+ size_t seedlen;
if (drbg == NULL)
return 0;
if (num < 0 || randomness < 0.0)
return 0;
- if (randomness > (double)drbg->max_entropylen) {
+ rand_drbg_lock(drbg);
+ seedlen = rand_drbg_seedlen(drbg);
+
+ buflen = (size_t)num;
+
+ if (buflen < seedlen || randomness < (double) seedlen) {
+#if defined(OPENSSL_RAND_SEED_NONE)
+ /*
+ * If no os entropy source is available, a reseeding will fail
+ * inevitably. So we use a trick to mix the buffer contents into
+ * the DRBG state without forcing a reseeding: we generate a
+ * dummy random byte, using the buffer content as additional data.
+ * Note: This won't work with RAND_DRBG_FLAG_CTR_NO_DF.
+ */
+ unsigned char dummy[1];
+
+ ret = RAND_DRBG_generate(drbg, dummy, sizeof(dummy), 0, buf, buflen);
+ rand_drbg_unlock(drbg);
+ return ret;
+#else
+ /*
+ * If an os entropy source is avaible then we declare the buffer content
+ * as additional data by setting randomness to zero and trigger a regular
+ * reseeding.
+ */
+ randomness = 0.0;
+#endif
+ }
+
+
+ if (randomness > (double)seedlen) {
/*
* The purpose of this check is to bound |randomness| by a
* relatively small value in order to prevent an integer
* overflow when multiplying by 8 in the rand_drbg_restart()
- * call below.
+ * call below. Note that randomness is measured in bytes,
+ * not bits, so this value corresponds to eight times the
+ * security strength.
*/
- return 0;
+ randomness = (double)seedlen;
}
- rand_drbg_lock(drbg);
- ret = rand_drbg_restart(drbg, buf,
- (size_t)(unsigned int)num,
- (size_t)(8*randomness));
+ ret = rand_drbg_restart(drbg, buf, buflen, (size_t)(8 * randomness));
rand_drbg_unlock(drbg);
return ret;
if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
return NULL;
- return drbg_master;
+ return master_drbg;
}
/*
if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
return NULL;
- drbg = CRYPTO_THREAD_get_local(&public_drbg_thread_local_key);
+ drbg = CRYPTO_THREAD_get_local(&public_drbg);
if (drbg == NULL) {
- ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
- drbg = drbg_setup(drbg_master);
- CRYPTO_THREAD_set_local(&public_drbg_thread_local_key, drbg);
+ if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND))
+ return NULL;
+ drbg = drbg_setup(master_drbg);
+ CRYPTO_THREAD_set_local(&public_drbg, drbg);
}
return drbg;
}
if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
return NULL;
- drbg = CRYPTO_THREAD_get_local(&private_drbg_thread_local_key);
+ drbg = CRYPTO_THREAD_get_local(&private_drbg);
if (drbg == NULL) {
- ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
- drbg = drbg_setup(drbg_master);
- CRYPTO_THREAD_set_local(&private_drbg_thread_local_key, drbg);
+ if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND))
+ return NULL;
+ drbg = drbg_setup(master_drbg);
+ CRYPTO_THREAD_set_local(&private_drbg, drbg);
}
return drbg;
}