2 * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include <openssl/crypto.h>
12 #include <openssl/err.h>
13 #include <openssl/rand.h>
15 #include "internal/thread_once.h"
16 #include "internal/rand_int.h"
17 #include "internal/cryptlib_int.h"
20 * Support framework for NIST SP 800-90A DRBG
22 * See manual page RAND_DRBG(7) for a general overview.
24 * The OpenSSL model is to have new and free functions, and that new
25 * does all initialization. That is not the NIST model, which has
26 * instantiation and un-instantiate, and re-use within a new/free
27 * lifecycle. (No doubt this comes from the desire to support hardware
28 * DRBG, where allocation of resources on something like an HSM is
29 * a much bigger deal than just re-setting an allocated resource.)
33 * The three shared DRBG instances
35 * There are three shared DRBG instances: <master>, <public>, and <private>.
41 * Not used directly by the application, only for reseeding the two other
42 * DRBGs. It reseeds itself by pulling either randomness from os entropy
43 * sources or by consuming randomness which was added by RAND_add().
45 * The <master> DRBG is a global instance which is accessed concurrently by
46 * all threads. The necessary locking is managed automatically by its child
47 * DRBG instances during reseeding.
49 static RAND_DRBG *master_drbg;
53 * Used by default for generating random bytes using RAND_bytes().
55 * The <public> DRBG is thread-local, i.e., there is one instance per thread.
57 static CRYPTO_THREAD_LOCAL public_drbg;
61 * Used by default for generating private keys using RAND_priv_bytes()
63 * The <private> DRBG is thread-local, i.e., there is one instance per thread.
65 static CRYPTO_THREAD_LOCAL private_drbg;
69 /* NIST SP 800-90A DRBG recommends the use of a personalization string. */
70 static const char ossl_pers_string[] = "OpenSSL NIST SP 800-90A DRBG";
72 static CRYPTO_ONCE rand_drbg_init = CRYPTO_ONCE_STATIC_INIT;
76 static int rand_drbg_type = RAND_DRBG_TYPE;
77 static unsigned int rand_drbg_flags = RAND_DRBG_FLAGS;
79 static unsigned int master_reseed_interval = MASTER_RESEED_INTERVAL;
80 static unsigned int slave_reseed_interval = SLAVE_RESEED_INTERVAL;
82 static time_t master_reseed_time_interval = MASTER_RESEED_TIME_INTERVAL;
83 static time_t slave_reseed_time_interval = SLAVE_RESEED_TIME_INTERVAL;
85 static RAND_DRBG *drbg_setup(RAND_DRBG *parent);
87 static RAND_DRBG *rand_drbg_new(int secure,
93 * Set/initialize |drbg| to be of type |type|, with optional |flags|.
95 * If |type| and |flags| are zero, use the defaults
97 * Returns 1 on success, 0 on failure.
99 int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags)
103 if (type == 0 && flags == 0) {
104 type = rand_drbg_type;
105 flags = rand_drbg_flags;
108 drbg->state = DRBG_UNINITIALISED;
114 RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE);
117 /* Uninitialized; that's okay. */
119 case NID_aes_128_ctr:
120 case NID_aes_192_ctr:
121 case NID_aes_256_ctr:
122 ret = drbg_ctr_init(drbg);
127 RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG);
132 * Set/initialize default |type| and |flag| for new drbg instances.
134 * Returns 1 on success, 0 on failure.
136 int RAND_DRBG_set_defaults(int type, unsigned int flags)
142 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_TYPE);
144 case NID_aes_128_ctr:
145 case NID_aes_192_ctr:
146 case NID_aes_256_ctr:
150 if ((flags & ~RAND_DRBG_USED_FLAGS) != 0) {
151 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_FLAGS);
155 rand_drbg_type = type;
156 rand_drbg_flags = flags;
163 * Allocate memory and initialize a new DRBG. The DRBG is allocated on
164 * the secure heap if |secure| is nonzero and the secure heap is enabled.
165 * The |parent|, if not NULL, will be used as random source for reseeding.
167 * Returns a pointer to the new DRBG instance on success, NULL on failure.
169 static RAND_DRBG *rand_drbg_new(int secure,
174 RAND_DRBG *drbg = secure ?
175 OPENSSL_secure_zalloc(sizeof(*drbg)) : OPENSSL_zalloc(sizeof(*drbg));
178 RANDerr(RAND_F_RAND_DRBG_NEW, ERR_R_MALLOC_FAILURE);
182 drbg->secure = secure && CRYPTO_secure_allocated(drbg);
183 drbg->fork_count = rand_fork_count;
184 drbg->parent = parent;
186 if (parent == NULL) {
187 drbg->reseed_interval = master_reseed_interval;
188 drbg->reseed_time_interval = master_reseed_time_interval;
190 drbg->reseed_interval = slave_reseed_interval;
191 drbg->reseed_time_interval = slave_reseed_time_interval;
194 if (RAND_DRBG_set(drbg, type, flags) == 0)
197 if (parent != NULL) {
198 rand_drbg_lock(parent);
199 if (drbg->strength > parent->strength) {
201 * We currently don't support the algorithm from NIST SP 800-90C
202 * 10.1.2 to use a weaker DRBG as source
204 rand_drbg_unlock(parent);
205 RANDerr(RAND_F_RAND_DRBG_NEW, RAND_R_PARENT_STRENGTH_TOO_WEAK);
208 rand_drbg_unlock(parent);
211 if (!RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy,
212 rand_drbg_cleanup_entropy,
220 OPENSSL_secure_free(drbg);
227 RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent)
229 return rand_drbg_new(0, type, flags, parent);
232 RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent)
234 return rand_drbg_new(1, type, flags, parent);
238 * Uninstantiate |drbg| and free all memory.
240 void RAND_DRBG_free(RAND_DRBG *drbg)
245 if (drbg->meth != NULL)
246 drbg->meth->uninstantiate(drbg);
247 CRYPTO_THREAD_lock_free(drbg->lock);
248 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data);
251 OPENSSL_secure_clear_free(drbg, sizeof(*drbg));
253 OPENSSL_clear_free(drbg, sizeof(*drbg));
257 * Instantiate |drbg|, after it has been initialized. Use |pers| and
258 * |perslen| as prediction-resistance input.
260 * Requires that drbg->lock is already locked for write, if non-null.
262 * Returns 1 on success, 0 on failure.
264 int RAND_DRBG_instantiate(RAND_DRBG *drbg,
265 const unsigned char *pers, size_t perslen)
267 unsigned char *nonce = NULL, *entropy = NULL;
268 size_t noncelen = 0, entropylen = 0;
269 size_t min_entropy = drbg->strength;
270 size_t min_entropylen = drbg->min_entropylen;
271 size_t max_entropylen = drbg->max_entropylen;
273 if (perslen > drbg->max_perslen) {
274 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
275 RAND_R_PERSONALISATION_STRING_TOO_LONG);
279 if (drbg->meth == NULL)
281 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
282 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
286 if (drbg->state != DRBG_UNINITIALISED) {
287 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
288 drbg->state == DRBG_ERROR ? RAND_R_IN_ERROR_STATE
289 : RAND_R_ALREADY_INSTANTIATED);
293 drbg->state = DRBG_ERROR;
296 * NIST SP800-90Ar1 section 9.1 says you can combine getting the entropy
297 * and nonce in 1 call by increasing the entropy with 50% and increasing
298 * the minimum length to accomadate the length of the nonce.
299 * We do this in case a nonce is require and get_nonce is NULL.
301 if (drbg->min_noncelen > 0 && drbg->get_nonce == NULL) {
302 min_entropy += drbg->strength / 2;
303 min_entropylen += drbg->min_noncelen;
304 max_entropylen += drbg->max_noncelen;
307 if (drbg->get_entropy != NULL)
308 entropylen = drbg->get_entropy(drbg, &entropy, min_entropy,
309 min_entropylen, max_entropylen, 0);
310 if (entropylen < min_entropylen
311 || entropylen > max_entropylen) {
312 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_ENTROPY);
316 if (drbg->min_noncelen > 0 && drbg->get_nonce != NULL) {
317 noncelen = drbg->get_nonce(drbg, &nonce, drbg->strength / 2,
318 drbg->min_noncelen, drbg->max_noncelen);
319 if (noncelen < drbg->min_noncelen || noncelen > drbg->max_noncelen) {
320 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_NONCE);
325 if (!drbg->meth->instantiate(drbg, entropy, entropylen,
326 nonce, noncelen, pers, perslen)) {
327 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_INSTANTIATING_DRBG);
331 drbg->state = DRBG_READY;
332 drbg->generate_counter = 0;
333 drbg->reseed_time = time(NULL);
334 if (drbg->reseed_counter > 0) {
335 if (drbg->parent == NULL)
336 drbg->reseed_counter++;
338 drbg->reseed_counter = drbg->parent->reseed_counter;
342 if (entropy != NULL && drbg->cleanup_entropy != NULL)
343 drbg->cleanup_entropy(drbg, entropy, entropylen);
344 if (nonce != NULL && drbg->cleanup_nonce!= NULL )
345 drbg->cleanup_nonce(drbg, nonce, noncelen);
346 if (drbg->pool != NULL) {
347 if (drbg->state == DRBG_READY) {
348 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
349 RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED);
350 drbg->state = DRBG_ERROR;
352 rand_pool_free(drbg->pool);
355 if (drbg->state == DRBG_READY)
361 * Uninstantiate |drbg|. Must be instantiated before it can be used.
363 * Requires that drbg->lock is already locked for write, if non-null.
365 * Returns 1 on success, 0 on failure.
367 int RAND_DRBG_uninstantiate(RAND_DRBG *drbg)
369 if (drbg->meth == NULL)
371 RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE,
372 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
376 /* Clear the entire drbg->ctr struct, then reset some important
377 * members of the drbg->ctr struct (e.g. keysize, df_ks) to their
380 drbg->meth->uninstantiate(drbg);
381 return RAND_DRBG_set(drbg, drbg->type, drbg->flags);
385 * Reseed |drbg|, mixing in the specified data
387 * Requires that drbg->lock is already locked for write, if non-null.
389 * Returns 1 on success, 0 on failure.
391 int RAND_DRBG_reseed(RAND_DRBG *drbg,
392 const unsigned char *adin, size_t adinlen,
393 int prediction_resistance)
395 unsigned char *entropy = NULL;
396 size_t entropylen = 0;
398 if (drbg->state == DRBG_ERROR) {
399 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_IN_ERROR_STATE);
402 if (drbg->state == DRBG_UNINITIALISED) {
403 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_NOT_INSTANTIATED);
409 else if (adinlen > drbg->max_adinlen) {
410 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ADDITIONAL_INPUT_TOO_LONG);
414 drbg->state = DRBG_ERROR;
415 if (drbg->get_entropy != NULL)
416 entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength,
417 drbg->min_entropylen,
418 drbg->max_entropylen,
419 prediction_resistance);
420 if (entropylen < drbg->min_entropylen
421 || entropylen > drbg->max_entropylen) {
422 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ERROR_RETRIEVING_ENTROPY);
426 if (!drbg->meth->reseed(drbg, entropy, entropylen, adin, adinlen))
429 drbg->state = DRBG_READY;
430 drbg->generate_counter = 0;
431 drbg->reseed_time = time(NULL);
432 if (drbg->reseed_counter > 0) {
433 if (drbg->parent == NULL)
434 drbg->reseed_counter++;
436 drbg->reseed_counter = drbg->parent->reseed_counter;
440 if (entropy != NULL && drbg->cleanup_entropy != NULL)
441 drbg->cleanup_entropy(drbg, entropy, entropylen);
442 if (drbg->state == DRBG_READY)
448 * Restart |drbg|, using the specified entropy or additional input
450 * Tries its best to get the drbg instantiated by all means,
451 * regardless of its current state.
453 * Optionally, a |buffer| of |len| random bytes can be passed,
454 * which is assumed to contain at least |entropy| bits of entropy.
456 * If |entropy| > 0, the buffer content is used as entropy input.
458 * If |entropy| == 0, the buffer content is used as additional input
460 * Returns 1 on success, 0 on failure.
462 * This function is used internally only.
464 int rand_drbg_restart(RAND_DRBG *drbg,
465 const unsigned char *buffer, size_t len, size_t entropy)
468 const unsigned char *adin = NULL;
471 if (drbg->pool != NULL) {
472 RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
473 rand_pool_free(drbg->pool);
477 if (buffer != NULL) {
479 if (drbg->max_entropylen < len) {
480 RANDerr(RAND_F_RAND_DRBG_RESTART,
481 RAND_R_ENTROPY_INPUT_TOO_LONG);
485 if (entropy > 8 * len) {
486 RANDerr(RAND_F_RAND_DRBG_RESTART, RAND_R_ENTROPY_OUT_OF_RANGE);
490 /* will be picked up by the rand_drbg_get_entropy() callback */
491 drbg->pool = rand_pool_new(entropy, len, len);
492 if (drbg->pool == NULL)
495 rand_pool_add(drbg->pool, buffer, len, entropy);
497 if (drbg->max_adinlen < len) {
498 RANDerr(RAND_F_RAND_DRBG_RESTART,
499 RAND_R_ADDITIONAL_INPUT_TOO_LONG);
507 /* repair error state */
508 if (drbg->state == DRBG_ERROR)
509 RAND_DRBG_uninstantiate(drbg);
511 /* repair uninitialized state */
512 if (drbg->state == DRBG_UNINITIALISED) {
513 /* reinstantiate drbg */
514 RAND_DRBG_instantiate(drbg,
515 (const unsigned char *) ossl_pers_string,
516 sizeof(ossl_pers_string) - 1);
517 /* already reseeded. prevent second reseeding below */
518 reseeded = (drbg->state == DRBG_READY);
521 /* refresh current state if entropy or additional input has been provided */
522 if (drbg->state == DRBG_READY) {
525 * mix in additional input without reseeding
527 * Similar to RAND_DRBG_reseed(), but the provided additional
528 * data |adin| is mixed into the current state without pulling
529 * entropy from the trusted entropy source using get_entropy().
530 * This is not a reseeding in the strict sense of NIST SP 800-90A.
532 drbg->meth->reseed(drbg, adin, adinlen, NULL, 0);
533 } else if (reseeded == 0) {
534 /* do a full reseeding if it has not been done yet above */
535 RAND_DRBG_reseed(drbg, NULL, 0, 0);
539 /* check whether a given entropy pool was cleared properly during reseed */
540 if (drbg->pool != NULL) {
541 drbg->state = DRBG_ERROR;
542 RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
543 rand_pool_free(drbg->pool);
548 return drbg->state == DRBG_READY;
552 * Generate |outlen| bytes into the buffer at |out|. Reseed if we need
553 * to or if |prediction_resistance| is set. Additional input can be
554 * sent in |adin| and |adinlen|.
556 * Requires that drbg->lock is already locked for write, if non-null.
558 * Returns 1 on success, 0 on failure.
561 int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
562 int prediction_resistance,
563 const unsigned char *adin, size_t adinlen)
565 int reseed_required = 0;
567 if (drbg->state != DRBG_READY) {
568 /* try to recover from previous errors */
569 rand_drbg_restart(drbg, NULL, 0, 0);
571 if (drbg->state == DRBG_ERROR) {
572 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_IN_ERROR_STATE);
575 if (drbg->state == DRBG_UNINITIALISED) {
576 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_NOT_INSTANTIATED);
581 if (outlen > drbg->max_request) {
582 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG);
585 if (adinlen > drbg->max_adinlen) {
586 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_ADDITIONAL_INPUT_TOO_LONG);
590 if (drbg->fork_count != rand_fork_count) {
591 drbg->fork_count = rand_fork_count;
595 if (drbg->reseed_interval > 0) {
596 if (drbg->generate_counter >= drbg->reseed_interval)
599 if (drbg->reseed_time_interval > 0) {
600 time_t now = time(NULL);
601 if (now < drbg->reseed_time
602 || now - drbg->reseed_time >= drbg->reseed_time_interval)
605 if (drbg->reseed_counter > 0 && drbg->parent != NULL) {
606 if (drbg->reseed_counter != drbg->parent->reseed_counter)
610 if (reseed_required || prediction_resistance) {
611 if (!RAND_DRBG_reseed(drbg, adin, adinlen, prediction_resistance)) {
612 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_RESEED_ERROR);
619 if (!drbg->meth->generate(drbg, out, outlen, adin, adinlen)) {
620 drbg->state = DRBG_ERROR;
621 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_GENERATE_ERROR);
625 drbg->generate_counter++;
631 * Generates |outlen| random bytes and stores them in |out|. It will
632 * using the given |drbg| to generate the bytes.
634 * Requires that drbg->lock is already locked for write, if non-null.
636 * Returns 1 on success 0 on failure.
638 int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen)
640 unsigned char *additional = NULL;
641 size_t additional_len;
645 additional_len = rand_drbg_get_additional_data(&additional, drbg->max_adinlen);
647 for ( ; outlen > 0; outlen -= chunk, out += chunk) {
649 if (chunk > drbg->max_request)
650 chunk = drbg->max_request;
651 ret = RAND_DRBG_generate(drbg, out, chunk, 0, additional, additional_len);
658 if (additional_len != 0)
659 OPENSSL_secure_clear_free(additional, additional_len);
665 * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
667 * Setting the callbacks is allowed only if the drbg has not been
668 * initialized yet. Otherwise, the operation will fail.
670 * Returns 1 on success, 0 on failure.
672 int RAND_DRBG_set_callbacks(RAND_DRBG *drbg,
673 RAND_DRBG_get_entropy_fn get_entropy,
674 RAND_DRBG_cleanup_entropy_fn cleanup_entropy,
675 RAND_DRBG_get_nonce_fn get_nonce,
676 RAND_DRBG_cleanup_nonce_fn cleanup_nonce)
678 if (drbg->state != DRBG_UNINITIALISED)
680 drbg->get_entropy = get_entropy;
681 drbg->cleanup_entropy = cleanup_entropy;
682 drbg->get_nonce = get_nonce;
683 drbg->cleanup_nonce = cleanup_nonce;
688 * Set the reseed interval.
690 * The drbg will reseed automatically whenever the number of generate
691 * requests exceeds the given reseed interval. If the reseed interval
692 * is 0, then this feature is disabled.
694 * Returns 1 on success, 0 on failure.
696 int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval)
698 if (interval > MAX_RESEED_INTERVAL)
700 drbg->reseed_interval = interval;
705 * Set the reseed time interval.
707 * The drbg will reseed automatically whenever the time elapsed since
708 * the last reseeding exceeds the given reseed time interval. For safety,
709 * a reseeding will also occur if the clock has been reset to a smaller
712 * Returns 1 on success, 0 on failure.
714 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval)
716 if (interval > MAX_RESEED_TIME_INTERVAL)
718 drbg->reseed_time_interval = interval;
723 * Set the default values for reseed (time) intervals of new DRBG instances
725 * The default values can be set independently for master DRBG instances
726 * (without a parent) and slave DRBG instances (with parent).
728 * Returns 1 on success, 0 on failure.
731 int RAND_DRBG_set_reseed_defaults(
732 unsigned int _master_reseed_interval,
733 unsigned int _slave_reseed_interval,
734 time_t _master_reseed_time_interval,
735 time_t _slave_reseed_time_interval
738 if (_master_reseed_interval > MAX_RESEED_INTERVAL
739 || _slave_reseed_interval > MAX_RESEED_INTERVAL)
742 if (_master_reseed_time_interval > MAX_RESEED_TIME_INTERVAL
743 || _slave_reseed_time_interval > MAX_RESEED_TIME_INTERVAL)
746 master_reseed_interval = _master_reseed_interval;
747 slave_reseed_interval = _slave_reseed_interval;
749 master_reseed_time_interval = _master_reseed_time_interval;
750 slave_reseed_time_interval = _slave_reseed_time_interval;
756 * Locks the given drbg. Locking a drbg which does not have locking
757 * enabled is considered a successful no-op.
759 * Returns 1 on success, 0 on failure.
761 int rand_drbg_lock(RAND_DRBG *drbg)
763 if (drbg->lock != NULL)
764 return CRYPTO_THREAD_write_lock(drbg->lock);
770 * Unlocks the given drbg. Unlocking a drbg which does not have locking
771 * enabled is considered a successful no-op.
773 * Returns 1 on success, 0 on failure.
775 int rand_drbg_unlock(RAND_DRBG *drbg)
777 if (drbg->lock != NULL)
778 return CRYPTO_THREAD_unlock(drbg->lock);
784 * Enables locking for the given drbg
786 * Locking can only be enabled if the random generator
787 * is in the uninitialized state.
789 * Returns 1 on success, 0 on failure.
791 int rand_drbg_enable_locking(RAND_DRBG *drbg)
793 if (drbg->state != DRBG_UNINITIALISED) {
794 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
795 RAND_R_DRBG_ALREADY_INITIALIZED);
799 if (drbg->lock == NULL) {
800 if (drbg->parent != NULL && drbg->parent->lock == NULL) {
801 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
802 RAND_R_PARENT_LOCKING_NOT_ENABLED);
806 drbg->lock = CRYPTO_THREAD_lock_new();
807 if (drbg->lock == NULL) {
808 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
809 RAND_R_FAILED_TO_CREATE_LOCK);
818 * Get and set the EXDATA
820 int RAND_DRBG_set_ex_data(RAND_DRBG *drbg, int idx, void *arg)
822 return CRYPTO_set_ex_data(&drbg->ex_data, idx, arg);
825 void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx)
827 return CRYPTO_get_ex_data(&drbg->ex_data, idx);
832 * The following functions provide a RAND_METHOD that works on the
833 * global DRBG. They lock.
837 * Allocates a new global DRBG on the secure heap (if enabled) and
838 * initializes it with default settings.
840 * Returns a pointer to the new DRBG instance on success, NULL on failure.
842 static RAND_DRBG *drbg_setup(RAND_DRBG *parent)
846 drbg = RAND_DRBG_secure_new(rand_drbg_type, rand_drbg_flags, parent);
850 /* Only the master DRBG needs to have a lock */
851 if (parent == NULL && rand_drbg_enable_locking(drbg) == 0)
854 /* enable seed propagation */
855 drbg->reseed_counter = 1;
858 * Ignore instantiation error so support just-in-time instantiation.
860 * The state of the drbg will be checked in RAND_DRBG_generate() and
861 * an automatic recovery is attempted.
863 RAND_DRBG_instantiate(drbg,
864 (const unsigned char *) ossl_pers_string,
865 sizeof(ossl_pers_string) - 1);
869 RAND_DRBG_free(drbg);
874 * Initialize the global DRBGs on first use.
875 * Returns 1 on success, 0 on failure.
877 DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init)
882 * ensure that libcrypto is initialized, otherwise the
883 * DRBG locks are not cleaned up properly
885 if (!OPENSSL_init_crypto(0, NULL))
888 ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
890 master_drbg = drbg_setup(NULL);
892 ret &= CRYPTO_THREAD_init_local(&private_drbg, NULL);
893 ret &= CRYPTO_THREAD_init_local(&public_drbg, NULL);
895 if (master_drbg == NULL || ret == 0)
901 /* Clean up the global DRBGs before exit */
902 void rand_drbg_cleanup_int(void)
904 RAND_DRBG_free(master_drbg);
907 CRYPTO_THREAD_cleanup_local(&private_drbg);
908 CRYPTO_THREAD_cleanup_local(&public_drbg);
911 void drbg_delete_thread_state()
915 drbg = CRYPTO_THREAD_get_local(&public_drbg);
916 RAND_DRBG_free(drbg);
918 drbg = CRYPTO_THREAD_get_local(&private_drbg);
919 RAND_DRBG_free(drbg);
922 /* Implements the default OpenSSL RAND_bytes() method */
923 static int drbg_bytes(unsigned char *out, int count)
926 RAND_DRBG *drbg = RAND_DRBG_get0_public();
931 ret = RAND_DRBG_bytes(drbg, out, count);
936 /* Implements the default OpenSSL RAND_add() method */
937 static int drbg_add(const void *buf, int num, double randomness)
940 RAND_DRBG *drbg = RAND_DRBG_get0_master();
945 if (num < 0 || randomness < 0.0)
948 if (randomness > (double)drbg->max_entropylen) {
950 * The purpose of this check is to bound |randomness| by a
951 * relatively small value in order to prevent an integer
952 * overflow when multiplying by 8 in the rand_drbg_restart()
958 rand_drbg_lock(drbg);
959 ret = rand_drbg_restart(drbg, buf,
960 (size_t)(unsigned int)num,
961 (size_t)(8*randomness));
962 rand_drbg_unlock(drbg);
967 /* Implements the default OpenSSL RAND_seed() method */
968 static int drbg_seed(const void *buf, int num)
970 return drbg_add(buf, num, num);
973 /* Implements the default OpenSSL RAND_status() method */
974 static int drbg_status(void)
977 RAND_DRBG *drbg = RAND_DRBG_get0_master();
982 rand_drbg_lock(drbg);
983 ret = drbg->state == DRBG_READY ? 1 : 0;
984 rand_drbg_unlock(drbg);
989 * Get the master DRBG.
990 * Returns pointer to the DRBG on success, NULL on failure.
993 RAND_DRBG *RAND_DRBG_get0_master(void)
995 if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
1002 * Get the public DRBG.
1003 * Returns pointer to the DRBG on success, NULL on failure.
1005 RAND_DRBG *RAND_DRBG_get0_public(void)
1009 if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
1012 drbg = CRYPTO_THREAD_get_local(&public_drbg);
1014 ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
1015 drbg = drbg_setup(master_drbg);
1016 CRYPTO_THREAD_set_local(&public_drbg, drbg);
1022 * Get the private DRBG.
1023 * Returns pointer to the DRBG on success, NULL on failure.
1025 RAND_DRBG *RAND_DRBG_get0_private(void)
1029 if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
1032 drbg = CRYPTO_THREAD_get_local(&private_drbg);
1034 ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
1035 drbg = drbg_setup(master_drbg);
1036 CRYPTO_THREAD_set_local(&private_drbg, drbg);
1041 RAND_METHOD rand_meth = {
1050 RAND_METHOD *RAND_OpenSSL(void)