/*
- * Copyright 2011-2017 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
#include "rand_lcl.h"
#include "internal/thread_once.h"
#include "internal/rand_int.h"
-
-static RAND_DRBG rand_drbg; /* The default global DRBG. */
-static RAND_DRBG priv_drbg; /* The global private-key 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";
+#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
* a much bigger deal than just re-setting an allocated resource.)
*/
+/*
+ * The three shared DRBG instances
+ *
+ * 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 randomness which was added by RAND_add().
+ *
+ * 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
+ *
+ * Used by default for generating random bytes using RAND_bytes().
+ *
+ * The <public> DRBG is thread-local, i.e., there is one instance per thread.
+ */
+static CRYPTO_THREAD_LOCAL public_drbg;
+/*
+ * The <private> DRBG
+ *
+ * Used by default for generating private keys using RAND_priv_bytes()
+ *
+ * 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 int drbg_setup(RAND_DRBG *drbg, const char *name);
+
+#define RAND_DRBG_TYPE_FLAGS ( \
+ RAND_DRBG_FLAG_MASTER | RAND_DRBG_FLAG_PUBLIC | RAND_DRBG_FLAG_PRIVATE )
+
+#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;
+
+/* 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 |nid|, with optional |flags|.
- * Return -2 if the type is not supported, 1 on success and -1 on
- * failure.
+ * Set/initialize |drbg| to be of type |type|, with optional |flags|.
+ *
+ * If |type| and |flags| are zero, use the defaults
+ *
+ * Returns 1 on success, 0 on failure.
*/
-int RAND_DRBG_set(RAND_DRBG *drbg, int nid, unsigned int flags)
+int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags)
{
int ret = 1;
+ if (type == 0 && flags == 0) {
+ 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 (type != drbg->type && drbg->type != 0 && drbg->meth != NULL) {
+ drbg->meth->uninstantiate(drbg);
+ }
+
drbg->state = DRBG_UNINITIALISED;
drbg->flags = flags;
- drbg->nid = nid;
+ drbg->type = type;
- switch (nid) {
- default:
- RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE);
- return -2;
- case 0:
+ if (type == 0) {
/* Uninitialized; that's okay. */
return 1;
- case NID_aes_128_ctr:
- case NID_aes_192_ctr:
- case NID_aes_256_ctr:
- ret = ctr_init(drbg);
- break;
+ } else if (is_ctr(type)) {
+ ret = drbg_ctr_init(drbg);
+ } else if (is_digest(type)) {
+ if (flags & RAND_DRBG_FLAG_HMAC)
+ ret = drbg_hmac_init(drbg);
+ else
+ ret = drbg_hash_init(drbg);
+ } else {
+ RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE);
+ return 0;
}
- if (ret < 0)
+ if (ret == 0)
RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG);
return ret;
}
/*
- * Allocate memory and initialize a new DRBG. The |parent|, if not
- * NULL, will be used to auto-seed this RAND_DRBG as needed.
+ * Set/initialize default |type| and |flag| for new drbg instances.
+ *
+ * Returns 1 on success, 0 on failure.
*/
-RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent)
+int RAND_DRBG_set_defaults(int type, unsigned int flags)
+{
+ int all;
+ if (!(is_digest(type) || is_ctr(type))) {
+ RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_TYPE);
+ return 0;
+ }
+
+ if ((flags & ~rand_drbg_used_flags) != 0) {
+ RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_FLAGS);
+ return 0;
+ }
+
+ 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;
+}
+
+
+/*
+ * 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.
+ */
+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;
+ return NULL;
}
+
+ drbg->secure = secure && CRYPTO_secure_allocated(drbg);
drbg->fork_count = rand_fork_count;
drbg->parent = parent;
- if (RAND_DRBG_set(drbg, type, flags) < 0)
+
+ 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;
+ }
+
+ if (RAND_DRBG_set(drbg, type, flags) == 0)
goto err;
if (parent != NULL) {
- if (!RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy,
- rand_drbg_cleanup_entropy,
- NULL, NULL))
+ rand_drbg_lock(parent);
+ if (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
+ */
+ rand_drbg_unlock(parent);
+ RANDerr(RAND_F_RAND_DRBG_NEW, RAND_R_PARENT_STRENGTH_TOO_WEAK);
goto err;
+ }
+ rand_drbg_unlock(parent);
}
return drbg;
-err:
- OPENSSL_free(drbg);
+ err:
+ 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 == NULL)
return;
- ctr_uninstantiate(drbg);
+ 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));
}
/*
* |perslen| as prediction-resistance input.
*
* Requires that drbg->lock is already locked for write, if non-null.
+ *
+ * Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_instantiate(RAND_DRBG *drbg,
const unsigned char *pers, size_t perslen)
{
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,
RAND_R_PERSONALISATION_STRING_TOO_LONG);
goto end;
}
+
+ if (drbg->meth == NULL) {
+ RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
+ RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
+ goto end;
+ }
+
if (drbg->state != DRBG_UNINITIALISED) {
RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
drbg->state == DRBG_ERROR ? RAND_R_IN_ERROR_STATE
}
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);
- 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;
}
}
- if (!ctr_instantiate(drbg, entropy, entropylen,
+ if (!drbg->meth->instantiate(drbg, entropy, entropylen,
nonce, noncelen, pers, perslen)) {
RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_INSTANTIATING_DRBG);
goto end;
}
drbg->state = DRBG_READY;
- drbg->reseed_counter = 1;
+ drbg->reseed_gen_counter = 1;
+ drbg->reseed_time = time(NULL);
+ 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;
* Uninstantiate |drbg|. Must be instantiated before it can be used.
*
* Requires that drbg->lock is already locked for write, if non-null.
+ *
+ * Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_uninstantiate(RAND_DRBG *drbg)
{
- int ret = ctr_uninstantiate(drbg);
+ int index = -1, type, flags;
+ if (drbg->meth == NULL) {
+ RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE,
+ RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
+ return 0;
+ }
- OPENSSL_cleanse(&drbg->ctr, sizeof(drbg->ctr));
- drbg->state = DRBG_UNINITIALISED;
- return ret;
+ /* Clear the entire drbg->ctr struct, then reset some important
+ * members of the drbg->ctr struct (e.g. keysize, df_ks) to their
+ * initial values.
+ */
+ drbg->meth->uninstantiate(drbg);
+
+ /* 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);
}
/*
* Reseed |drbg|, mixing in the specified data
*
* Requires that drbg->lock is already locked for write, if non-null.
+ *
+ * Returns 1 on success, 0 on failure.
*/
int RAND_DRBG_reseed(RAND_DRBG *drbg,
- const unsigned char *adin, size_t adinlen)
+ const unsigned char *adin, size_t adinlen,
+ int prediction_resistance)
{
unsigned char *entropy = NULL;
size_t entropylen = 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);
+ 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;
}
- if (!ctr_reseed(drbg, entropy, entropylen, adin, adinlen))
+ if (!drbg->meth->reseed(drbg, entropy, entropylen, adin, adinlen))
goto end;
+
drbg->state = DRBG_READY;
- drbg->reseed_counter = 1;
+ drbg->reseed_gen_counter = 1;
+ drbg->reseed_time = time(NULL);
+ 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)
if (drbg->pool != NULL) {
RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
- RAND_POOL_free(drbg->pool);
+ drbg->state = DRBG_ERROR;
+ rand_pool_free(drbg->pool);
drbg->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);
+ drbg->pool = rand_pool_attach(buffer, len, entropy);
if (drbg->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;
/* repair uninitialized state */
if (drbg->state == DRBG_UNINITIALISED) {
- drbg_setup(drbg, NULL);
+ /* reinstantiate drbg */
+ RAND_DRBG_instantiate(drbg,
+ (const unsigned char *) ossl_pers_string,
+ sizeof(ossl_pers_string) - 1);
/* already reseeded. prevent second reseeding below */
reseeded = (drbg->state == DRBG_READY);
}
* entropy from the trusted entropy source using get_entropy().
* This is not a reseeding in the strict sense of NIST SP 800-90A.
*/
- ctr_reseed(drbg, adin, adinlen, NULL, 0);
+ drbg->meth->reseed(drbg, adin, adinlen, NULL, 0);
} else if (reseeded == 0) {
/* do a full reseeding if it has not been done yet above */
- RAND_DRBG_reseed(drbg, NULL, 0);
+ RAND_DRBG_reseed(drbg, NULL, 0, 0);
}
}
- /* 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->pool);
+ drbg->pool = NULL;
return drbg->state == DRBG_READY;
}
reseed_required = 1;
}
- if (drbg->reseed_counter >= drbg->reseed_interval)
- reseed_required = 1;
+ if (drbg->reseed_interval > 0) {
+ if (drbg->reseed_gen_counter > drbg->reseed_interval)
+ reseed_required = 1;
+ }
+ if (drbg->reseed_time_interval > 0) {
+ time_t now = time(NULL);
+ if (now < drbg->reseed_time
+ || now - drbg->reseed_time >= drbg->reseed_time_interval)
+ reseed_required = 1;
+ }
+ 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;
+ }
if (reseed_required || prediction_resistance) {
- if (!RAND_DRBG_reseed(drbg, adin, adinlen)) {
+ if (!RAND_DRBG_reseed(drbg, adin, adinlen, prediction_resistance)) {
RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_RESEED_ERROR);
return 0;
}
adinlen = 0;
}
- if (!ctr_generate(drbg, out, outlen, adin, adinlen)) {
+ if (!drbg->meth->generate(drbg, out, outlen, adin, adinlen)) {
drbg->state = DRBG_ERROR;
RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_GENERATE_ERROR);
return 0;
}
- drbg->reseed_counter++;
+ drbg->reseed_gen_counter++;
return 1;
}
/*
- * 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.
+ * Generates |outlen| random bytes and stores them in |out|. It will
+ * using the given |drbg| to generate the bytes.
*
- * If the callback fails to acquire at least |entropy| bits of
- * randomness, it shall return a buffer length of 0.
- *
- * CLEANUP_ENTROPY
- *
- * void cleanup_entropy(RAND_DRBG *ctx,
- * unsigned char *out, size_t outlen);
+ * Requires that drbg->lock is already locked for write, if non-null.
*
- * 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.
+ * Returns 1 on success 0 on failure.
+ */
+int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen)
+{
+ 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);
+
+ 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 ret;
+}
+
+/*
+ * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
*
- * GET_NONCE, CLEANUP_NONCE
+ * Setting the callbacks is allowed only if the drbg has not been
+ * initialized yet. Otherwise, the operation will fail.
*
- * 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;
/*
* Set the reseed interval.
+ *
+ * The drbg will reseed automatically whenever the number of generate
+ * requests exceeds the given reseed interval. If the reseed interval
+ * is 0, then this feature is disabled.
+ *
+ * Returns 1 on success, 0 on failure.
*/
-int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, int interval)
+int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval)
{
- if (interval < 0 || interval > MAX_RESEED)
+ if (interval > MAX_RESEED_INTERVAL)
return 0;
drbg->reseed_interval = interval;
return 1;
}
+/*
+ * Set the reseed time interval.
+ *
+ * The drbg will reseed automatically whenever the time elapsed since
+ * the last reseeding exceeds the given reseed time interval. For safety,
+ * a reseeding will also occur if the clock has been reset to a smaller
+ * value.
+ *
+ * Returns 1 on success, 0 on failure.
+ */
+int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval)
+{
+ if (interval > MAX_RESEED_TIME_INTERVAL)
+ return 0;
+ drbg->reseed_time_interval = interval;
+ 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
*/
*/
/*
- * Initializes the DRBG with default settings.
- * For global DRBGs a global lock is created with the given name
- * Returns 1 on success, 0 on failure
+ * Allocates a new global DRBG on the secure heap (if enabled) and
+ * initializes it with default settings.
+ *
+ * Returns a pointer to the new DRBG instance on success, NULL on failure.
*/
-static int drbg_setup(RAND_DRBG *drbg, const char *name)
+static RAND_DRBG *drbg_setup(RAND_DRBG *parent, int drbg_type)
{
- int ret = 1;
+ RAND_DRBG *drbg;
- if (name != NULL) {
- if (drbg->lock != NULL) {
- RANDerr(RAND_F_DRBG_SETUP, ERR_R_INTERNAL_ERROR);
- return 0;
- }
+ drbg = RAND_DRBG_secure_new(rand_drbg_type[drbg_type],
+ rand_drbg_flags[drbg_type], parent);
+ if (drbg == NULL)
+ return NULL;
- drbg->lock = CRYPTO_THREAD_glock_new(name);
- if (drbg->lock == NULL) {
- RANDerr(RAND_F_DRBG_SETUP, RAND_R_FAILED_TO_CREATE_LOCK);
- return 0;
- }
- }
+ /* Only the master DRBG needs to have a lock */
+ if (parent == NULL && rand_drbg_enable_locking(drbg) == 0)
+ goto err;
+
+ /* enable seed propagation */
+ tsan_store(&drbg->reseed_prop_counter, 1);
- ret &= RAND_DRBG_set(drbg,
- RAND_DRBG_NID, RAND_DRBG_FLAG_CTR_USE_DF) == 1;
- ret &= RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy,
- rand_drbg_cleanup_entropy, NULL, NULL) == 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);
- return ret;
+ (void)RAND_DRBG_instantiate(drbg,
+ (const unsigned char *) ossl_pers_string,
+ sizeof(ossl_pers_string) - 1);
+ return drbg;
+
+err:
+ RAND_DRBG_free(drbg);
+ return NULL;
}
/*
*/
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;
- ret &= drbg_setup(&rand_drbg, "rand_drbg");
- ret &= drbg_setup(&priv_drbg, "priv_drbg");
+ if (!CRYPTO_THREAD_init_local(&private_drbg, NULL))
+ return 0;
- return ret;
-}
+ if (!CRYPTO_THREAD_init_local(&public_drbg, NULL))
+ goto err1;
-/* Cleans up the given global DRBG */
-static void drbg_cleanup(RAND_DRBG *drbg)
-{
- CRYPTO_THREAD_lock_free(drbg->lock);
- RAND_DRBG_uninstantiate(drbg);
+ 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)
{
- drbg_cleanup(&rand_drbg);
- drbg_cleanup(&priv_drbg);
+ if (master_drbg != NULL) {
+ RAND_DRBG_free(master_drbg);
+ master_drbg = NULL;
+
+ CRYPTO_THREAD_cleanup_local(&private_drbg);
+ CRYPTO_THREAD_cleanup_local(&public_drbg);
+ }
+}
+
+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);
}
/* Implements the default OpenSSL RAND_bytes() method */
static int drbg_bytes(unsigned char *out, int count)
{
- int ret = 0;
- size_t chunk;
- RAND_DRBG *drbg = RAND_DRBG_get0_global();
+ 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;
+ ret = RAND_DRBG_bytes(drbg, out, count);
- 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;
+ return ret;
+}
+
+/*
+ * Calculates the minimum length of a full entropy buffer
+ * which is necessary to seed (i.e. instantiate) the DRBG
+ * successfully.
+ *
+ * NOTE: There is a copy of this function in drbgtest.c.
+ * If you change anything here, you need to update
+ * the copy accordingly.
+ */
+static 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;
}
- ret = 1;
-err:
- CRYPTO_THREAD_unlock(drbg->lock);
- return ret;
+ /*
+ * 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_global();
+ 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) {
+ 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.
+ */
+ unsigned char dummy[1];
+
+ return RAND_DRBG_generate(drbg, dummy, sizeof(dummy), 0, buf, buflen);
+#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;
}
- CRYPTO_THREAD_write_lock(drbg->lock);
- ret = rand_drbg_restart(drbg, buf,
- (size_t)(unsigned int)num,
- (size_t)(8*randomness));
- CRYPTO_THREAD_unlock(drbg->lock);
+ rand_drbg_lock(drbg);
+ ret = rand_drbg_restart(drbg, buf, buflen, (size_t)(8 * randomness));
+ rand_drbg_unlock(drbg);
return ret;
}
static int drbg_status(void)
{
int ret;
- RAND_DRBG *drbg = RAND_DRBG_get0_global();
+ RAND_DRBG *drbg = RAND_DRBG_get0_master();
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;
}
/*
- * Get the global public DRBG.
+ * Get the master DRBG.
* Returns pointer to the DRBG on success, NULL on failure.
+ *
*/
-RAND_DRBG *RAND_DRBG_get0_global(void)
+RAND_DRBG *RAND_DRBG_get0_master(void)
{
if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
return NULL;
- return &rand_drbg;
+ return master_drbg;
}
/*
- * Get the global private DRBG.
+ * Get the public DRBG.
* Returns pointer to the DRBG on success, NULL on failure.
*/
-RAND_DRBG *RAND_DRBG_get0_priv_global(void)
+RAND_DRBG *RAND_DRBG_get0_public(void)
{
+ RAND_DRBG *drbg;
+
if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
return NULL;
- return &priv_drbg;
+ drbg = CRYPTO_THREAD_get_local(&public_drbg);
+ if (drbg == NULL) {
+ 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;
+}
+
+/*
+ * Get the private DRBG.
+ * Returns pointer to the DRBG on success, NULL on failure.
+ */
+RAND_DRBG *RAND_DRBG_get0_private(void)
+{
+ RAND_DRBG *drbg;
+
+ if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
+ return NULL;
+
+ drbg = CRYPTO_THREAD_get_local(&private_drbg);
+ if (drbg == NULL) {
+ 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;
}
RAND_METHOD rand_meth = {
projects / openssl.git / blobdiff