/*
* Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
*
- * Licensed under the OpenSSL license (the "License"). You may not use
+ * Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
/* 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 const char ossl_pers_string[] = DRBG_DEFAULT_PERS_STRING;
static CRYPTO_ONCE rand_drbg_init = CRYPTO_ONCE_STATIC_INIT;
+#define RAND_DRBG_TYPE_FLAGS ( \
+ RAND_DRBG_FLAG_MASTER | RAND_DRBG_FLAG_PUBLIC | RAND_DRBG_FLAG_PRIVATE )
-static int rand_drbg_type = RAND_DRBG_TYPE;
-static unsigned int rand_drbg_flags = RAND_DRBG_FLAGS;
+#define RAND_DRBG_TYPE_MASTER 0
+#define RAND_DRBG_TYPE_PUBLIC 1
+#define RAND_DRBG_TYPE_PRIVATE 2
+
+/* Defaults */
+static int rand_drbg_type[3] = {
+ RAND_DRBG_TYPE, /* Master */
+ RAND_DRBG_TYPE, /* Public */
+ RAND_DRBG_TYPE /* Private */
+};
+static unsigned int rand_drbg_flags[3] = {
+ RAND_DRBG_FLAGS | RAND_DRBG_FLAG_MASTER, /* Master */
+ RAND_DRBG_FLAGS | RAND_DRBG_FLAG_PUBLIC, /* Public */
+ RAND_DRBG_FLAGS | RAND_DRBG_FLAG_PRIVATE /* Private */
+};
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);
+/* 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 | RAND_DRBG_FLAG_HMAC | RAND_DRBG_TYPE_FLAGS;
+
+
+static RAND_DRBG *drbg_setup(RAND_DRBG *parent, int drbg_type);
static RAND_DRBG *rand_drbg_new(int secure,
int type,
unsigned int flags,
RAND_DRBG *parent);
+static int is_ctr(int type)
+{
+ switch (type) {
+ case NID_aes_128_ctr:
+ case NID_aes_192_ctr:
+ case NID_aes_256_ctr:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static int is_digest(int type)
+{
+ switch (type) {
+ case NID_sha1:
+ case NID_sha224:
+ case NID_sha256:
+ case NID_sha384:
+ case NID_sha512:
+ case NID_sha512_224:
+ case NID_sha512_256:
+ case NID_sha3_224:
+ case NID_sha3_256:
+ case NID_sha3_384:
+ case NID_sha3_512:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
/*
* Set/initialize |drbg| to be of type |type|, with optional |flags|.
*
int ret = 1;
if (type == 0 && flags == 0) {
- type = rand_drbg_type;
- flags = rand_drbg_flags;
+ type = rand_drbg_type[RAND_DRBG_TYPE_MASTER];
+ flags = rand_drbg_flags[RAND_DRBG_TYPE_MASTER];
+ }
+
+ /* 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:
- RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE);
- return 0;
- case 0:
+ if (type == 0) {
/* Uninitialized; that's okay. */
+ drbg->meth = NULL;
return 1;
- case NID_aes_128_ctr:
- case NID_aes_192_ctr:
- case NID_aes_256_ctr:
+ } else if (is_ctr(type)) {
ret = drbg_ctr_init(drbg);
- break;
+ } else if (is_digest(type)) {
+ if (flags & RAND_DRBG_FLAG_HMAC)
+ ret = drbg_hmac_init(drbg);
+ else
+ ret = drbg_hash_init(drbg);
+ } else {
+ drbg->type = 0;
+ drbg->flags = 0;
+ drbg->meth = NULL;
+ RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE);
+ return 0;
}
- if (ret == 0)
+ if (ret == 0) {
+ drbg->state = DRBG_ERROR;
RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG);
+ }
return ret;
}
*/
int RAND_DRBG_set_defaults(int type, unsigned int flags)
{
- int ret = 1;
-
- switch (type) {
- default:
+ int all;
+ if (!(is_digest(type) || is_ctr(type))) {
RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_TYPE);
return 0;
- case NID_aes_128_ctr:
- case NID_aes_192_ctr:
- case NID_aes_256_ctr:
- 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;
}
- rand_drbg_type = type;
- rand_drbg_flags = flags;
-
- return ret;
+ all = ((flags & RAND_DRBG_TYPE_FLAGS) == 0);
+ if (all || (flags & RAND_DRBG_FLAG_MASTER) != 0) {
+ rand_drbg_type[RAND_DRBG_TYPE_MASTER] = type;
+ rand_drbg_flags[RAND_DRBG_TYPE_MASTER] = flags | RAND_DRBG_FLAG_MASTER;
+ }
+ if (all || (flags & RAND_DRBG_FLAG_PUBLIC) != 0) {
+ rand_drbg_type[RAND_DRBG_TYPE_PUBLIC] = type;
+ rand_drbg_flags[RAND_DRBG_TYPE_PUBLIC] = flags | RAND_DRBG_FLAG_PUBLIC;
+ }
+ if (all || (flags & RAND_DRBG_FLAG_PRIVATE) != 0) {
+ rand_drbg_type[RAND_DRBG_TYPE_PRIVATE] = type;
+ rand_drbg_flags[RAND_DRBG_TYPE_PRIVATE] = flags | RAND_DRBG_FLAG_PRIVATE;
+ }
+ return 1;
}
unsigned int flags,
RAND_DRBG *parent)
{
- RAND_DRBG *drbg = secure ?
- OPENSSL_secure_zalloc(sizeof(*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);
drbg->parent = parent;
if (parent == NULL) {
+#ifdef FIPS_MODE
+ drbg->get_entropy = rand_crngt_get_entropy;
+ drbg->cleanup_entropy = rand_crngt_cleanup_entropy;
+#else
+ drbg->get_entropy = rand_drbg_get_entropy;
+ drbg->cleanup_entropy = rand_drbg_cleanup_entropy;
+#endif
+#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)
- {
+ int index = -1, type, flags;
+ if (drbg->meth == NULL) {
+ drbg->state = DRBG_ERROR;
RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE,
RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
return 0;
* initial values.
*/
drbg->meth->uninstantiate(drbg);
- return RAND_DRBG_set(drbg, drbg->type, drbg->flags);
+
+ /* The reset uses the default values for type and flags */
+ if (drbg->flags & RAND_DRBG_FLAG_MASTER)
+ index = RAND_DRBG_TYPE_MASTER;
+ else if (drbg->flags & RAND_DRBG_FLAG_PRIVATE)
+ index = RAND_DRBG_TYPE_PRIVATE;
+ else if (drbg->flags & RAND_DRBG_FLAG_PUBLIC)
+ index = RAND_DRBG_TYPE_PUBLIC;
+
+ if (index != -1) {
+ flags = rand_drbg_flags[index];
+ type = rand_drbg_type[index];
+ } else {
+ flags = drbg->flags;
+ type = drbg->type;
+ }
+ return RAND_DRBG_set(drbg, type, flags);
}
/*
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;
- additional_len = rand_drbg_get_additional_data(&additional, drbg->max_adinlen);
+ 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(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;
}
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;
*
* Returns a pointer to the new DRBG instance on success, NULL on failure.
*/
-static RAND_DRBG *drbg_setup(RAND_DRBG *parent)
+static RAND_DRBG *drbg_setup(RAND_DRBG *parent, int drbg_type)
{
RAND_DRBG *drbg;
- drbg = RAND_DRBG_secure_new(rand_drbg_type, rand_drbg_flags, parent);
+ drbg = RAND_DRBG_secure_new(rand_drbg_type[drbg_type],
+ rand_drbg_flags[drbg_type], parent);
if (drbg == NULL)
return NULL;
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);
-
- master_drbg = drbg_setup(NULL);
+ if (!CRYPTO_THREAD_init_local(&private_drbg, NULL))
+ return 0;
- ret &= CRYPTO_THREAD_init_local(&private_drbg, NULL);
- ret &= CRYPTO_THREAD_init_local(&public_drbg, NULL);
+ if (!CRYPTO_THREAD_init_local(&public_drbg, NULL))
+ goto err1;
- if (master_drbg == NULL || ret == 0)
- return 0;
+ master_drbg = drbg_setup(NULL, RAND_DRBG_TYPE_MASTER);
+ 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(master_drbg);
- master_drbg = NULL;
+ if (master_drbg != NULL) {
+ RAND_DRBG_free(master_drbg);
+ master_drbg = NULL;
- CRYPTO_THREAD_cleanup_local(&private_drbg);
- CRYPTO_THREAD_cleanup_local(&public_drbg);
+ 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);
+ CRYPTO_THREAD_set_local(&public_drbg, NULL);
RAND_DRBG_free(drbg);
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;
drbg = CRYPTO_THREAD_get_local(&public_drbg);
if (drbg == NULL) {
- ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
- drbg = drbg_setup(master_drbg);
+ if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND))
+ return NULL;
+ drbg = drbg_setup(master_drbg, RAND_DRBG_TYPE_PUBLIC);
CRYPTO_THREAD_set_local(&public_drbg, drbg);
}
return drbg;
drbg = CRYPTO_THREAD_get_local(&private_drbg);
if (drbg == NULL) {
- ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
- drbg = drbg_setup(master_drbg);
+ if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND))
+ return NULL;
+ drbg = drbg_setup(master_drbg, RAND_DRBG_TYPE_PRIVATE);
CRYPTO_THREAD_set_local(&private_drbg, drbg);
}
return drbg;
projects / openssl.git / blobdiff