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->get_entropy = rand_drbg_get_entropy;
188 drbg->cleanup_entropy = rand_drbg_cleanup_entropy;
189 #ifndef RAND_DRBG_GET_RANDOM_NONCE
190 drbg->get_nonce = rand_drbg_get_nonce;
191 drbg->cleanup_nonce = rand_drbg_cleanup_nonce;
194 drbg->reseed_interval = master_reseed_interval;
195 drbg->reseed_time_interval = master_reseed_time_interval;
197 drbg->get_entropy = rand_drbg_get_entropy;
198 drbg->cleanup_entropy = rand_drbg_cleanup_entropy;
200 * Do not provide nonce callbacks, the child DRBGs will
201 * obtain their nonce using random bits from the parent.
204 drbg->reseed_interval = slave_reseed_interval;
205 drbg->reseed_time_interval = slave_reseed_time_interval;
208 if (RAND_DRBG_set(drbg, type, flags) == 0)
211 if (parent != NULL) {
212 rand_drbg_lock(parent);
213 if (drbg->strength > parent->strength) {
215 * We currently don't support the algorithm from NIST SP 800-90C
216 * 10.1.2 to use a weaker DRBG as source
218 rand_drbg_unlock(parent);
219 RANDerr(RAND_F_RAND_DRBG_NEW, RAND_R_PARENT_STRENGTH_TOO_WEAK);
222 rand_drbg_unlock(parent);
229 OPENSSL_secure_free(drbg);
236 RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent)
238 return rand_drbg_new(0, type, flags, parent);
241 RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent)
243 return rand_drbg_new(1, type, flags, parent);
247 * Uninstantiate |drbg| and free all memory.
249 void RAND_DRBG_free(RAND_DRBG *drbg)
254 if (drbg->meth != NULL)
255 drbg->meth->uninstantiate(drbg);
256 CRYPTO_THREAD_lock_free(drbg->lock);
257 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data);
260 OPENSSL_secure_clear_free(drbg, sizeof(*drbg));
262 OPENSSL_clear_free(drbg, sizeof(*drbg));
266 * Instantiate |drbg|, after it has been initialized. Use |pers| and
267 * |perslen| as prediction-resistance input.
269 * Requires that drbg->lock is already locked for write, if non-null.
271 * Returns 1 on success, 0 on failure.
273 int RAND_DRBG_instantiate(RAND_DRBG *drbg,
274 const unsigned char *pers, size_t perslen)
276 unsigned char *nonce = NULL, *entropy = NULL;
277 size_t noncelen = 0, entropylen = 0;
278 size_t min_entropy = drbg->strength;
279 size_t min_entropylen = drbg->min_entropylen;
280 size_t max_entropylen = drbg->max_entropylen;
282 if (perslen > drbg->max_perslen) {
283 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
284 RAND_R_PERSONALISATION_STRING_TOO_LONG);
288 if (drbg->meth == NULL)
290 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
291 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
295 if (drbg->state != DRBG_UNINITIALISED) {
296 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
297 drbg->state == DRBG_ERROR ? RAND_R_IN_ERROR_STATE
298 : RAND_R_ALREADY_INSTANTIATED);
302 drbg->state = DRBG_ERROR;
305 * NIST SP800-90Ar1 section 9.1 says you can combine getting the entropy
306 * and nonce in 1 call by increasing the entropy with 50% and increasing
307 * the minimum length to accomadate the length of the nonce.
308 * We do this in case a nonce is require and get_nonce is NULL.
310 if (drbg->min_noncelen > 0 && drbg->get_nonce == NULL) {
311 min_entropy += drbg->strength / 2;
312 min_entropylen += drbg->min_noncelen;
313 max_entropylen += drbg->max_noncelen;
316 if (drbg->get_entropy != NULL)
317 entropylen = drbg->get_entropy(drbg, &entropy, min_entropy,
318 min_entropylen, max_entropylen, 0);
319 if (entropylen < min_entropylen
320 || entropylen > max_entropylen) {
321 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_ENTROPY);
325 if (drbg->min_noncelen > 0 && drbg->get_nonce != NULL) {
326 noncelen = drbg->get_nonce(drbg, &nonce, drbg->strength / 2,
327 drbg->min_noncelen, drbg->max_noncelen);
328 if (noncelen < drbg->min_noncelen || noncelen > drbg->max_noncelen) {
329 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_NONCE);
334 if (!drbg->meth->instantiate(drbg, entropy, entropylen,
335 nonce, noncelen, pers, perslen)) {
336 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_INSTANTIATING_DRBG);
340 drbg->state = DRBG_READY;
341 drbg->generate_counter = 0;
342 drbg->reseed_time = time(NULL);
343 if (drbg->reseed_counter > 0) {
344 if (drbg->parent == NULL)
345 drbg->reseed_counter++;
347 drbg->reseed_counter = drbg->parent->reseed_counter;
351 if (entropy != NULL && drbg->cleanup_entropy != NULL)
352 drbg->cleanup_entropy(drbg, entropy, entropylen);
353 if (nonce != NULL && drbg->cleanup_nonce!= NULL )
354 drbg->cleanup_nonce(drbg, nonce, noncelen);
355 if (drbg->pool != NULL) {
356 if (drbg->state == DRBG_READY) {
357 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
358 RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED);
359 drbg->state = DRBG_ERROR;
361 rand_pool_free(drbg->pool);
364 if (drbg->state == DRBG_READY)
370 * Uninstantiate |drbg|. Must be instantiated before it can be used.
372 * Requires that drbg->lock is already locked for write, if non-null.
374 * Returns 1 on success, 0 on failure.
376 int RAND_DRBG_uninstantiate(RAND_DRBG *drbg)
378 if (drbg->meth == NULL)
380 RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE,
381 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
385 /* Clear the entire drbg->ctr struct, then reset some important
386 * members of the drbg->ctr struct (e.g. keysize, df_ks) to their
389 drbg->meth->uninstantiate(drbg);
390 return RAND_DRBG_set(drbg, drbg->type, drbg->flags);
394 * Reseed |drbg|, mixing in the specified data
396 * Requires that drbg->lock is already locked for write, if non-null.
398 * Returns 1 on success, 0 on failure.
400 int RAND_DRBG_reseed(RAND_DRBG *drbg,
401 const unsigned char *adin, size_t adinlen,
402 int prediction_resistance)
404 unsigned char *entropy = NULL;
405 size_t entropylen = 0;
407 if (drbg->state == DRBG_ERROR) {
408 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_IN_ERROR_STATE);
411 if (drbg->state == DRBG_UNINITIALISED) {
412 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_NOT_INSTANTIATED);
418 else if (adinlen > drbg->max_adinlen) {
419 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ADDITIONAL_INPUT_TOO_LONG);
423 drbg->state = DRBG_ERROR;
424 if (drbg->get_entropy != NULL)
425 entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength,
426 drbg->min_entropylen,
427 drbg->max_entropylen,
428 prediction_resistance);
429 if (entropylen < drbg->min_entropylen
430 || entropylen > drbg->max_entropylen) {
431 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ERROR_RETRIEVING_ENTROPY);
435 if (!drbg->meth->reseed(drbg, entropy, entropylen, adin, adinlen))
438 drbg->state = DRBG_READY;
439 drbg->generate_counter = 0;
440 drbg->reseed_time = time(NULL);
441 if (drbg->reseed_counter > 0) {
442 if (drbg->parent == NULL)
443 drbg->reseed_counter++;
445 drbg->reseed_counter = drbg->parent->reseed_counter;
449 if (entropy != NULL && drbg->cleanup_entropy != NULL)
450 drbg->cleanup_entropy(drbg, entropy, entropylen);
451 if (drbg->state == DRBG_READY)
457 * Restart |drbg|, using the specified entropy or additional input
459 * Tries its best to get the drbg instantiated by all means,
460 * regardless of its current state.
462 * Optionally, a |buffer| of |len| random bytes can be passed,
463 * which is assumed to contain at least |entropy| bits of entropy.
465 * If |entropy| > 0, the buffer content is used as entropy input.
467 * If |entropy| == 0, the buffer content is used as additional input
469 * Returns 1 on success, 0 on failure.
471 * This function is used internally only.
473 int rand_drbg_restart(RAND_DRBG *drbg,
474 const unsigned char *buffer, size_t len, size_t entropy)
477 const unsigned char *adin = NULL;
480 if (drbg->pool != NULL) {
481 RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
482 rand_pool_free(drbg->pool);
486 if (buffer != NULL) {
488 if (drbg->max_entropylen < len) {
489 RANDerr(RAND_F_RAND_DRBG_RESTART,
490 RAND_R_ENTROPY_INPUT_TOO_LONG);
494 if (entropy > 8 * len) {
495 RANDerr(RAND_F_RAND_DRBG_RESTART, RAND_R_ENTROPY_OUT_OF_RANGE);
499 /* will be picked up by the rand_drbg_get_entropy() callback */
500 drbg->pool = rand_pool_new(entropy, len, len);
501 if (drbg->pool == NULL)
504 rand_pool_add(drbg->pool, buffer, len, entropy);
506 if (drbg->max_adinlen < len) {
507 RANDerr(RAND_F_RAND_DRBG_RESTART,
508 RAND_R_ADDITIONAL_INPUT_TOO_LONG);
516 /* repair error state */
517 if (drbg->state == DRBG_ERROR)
518 RAND_DRBG_uninstantiate(drbg);
520 /* repair uninitialized state */
521 if (drbg->state == DRBG_UNINITIALISED) {
522 /* reinstantiate drbg */
523 RAND_DRBG_instantiate(drbg,
524 (const unsigned char *) ossl_pers_string,
525 sizeof(ossl_pers_string) - 1);
526 /* already reseeded. prevent second reseeding below */
527 reseeded = (drbg->state == DRBG_READY);
530 /* refresh current state if entropy or additional input has been provided */
531 if (drbg->state == DRBG_READY) {
534 * mix in additional input without reseeding
536 * Similar to RAND_DRBG_reseed(), but the provided additional
537 * data |adin| is mixed into the current state without pulling
538 * entropy from the trusted entropy source using get_entropy().
539 * This is not a reseeding in the strict sense of NIST SP 800-90A.
541 drbg->meth->reseed(drbg, adin, adinlen, NULL, 0);
542 } else if (reseeded == 0) {
543 /* do a full reseeding if it has not been done yet above */
544 RAND_DRBG_reseed(drbg, NULL, 0, 0);
548 /* check whether a given entropy pool was cleared properly during reseed */
549 if (drbg->pool != NULL) {
550 drbg->state = DRBG_ERROR;
551 RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
552 rand_pool_free(drbg->pool);
557 return drbg->state == DRBG_READY;
561 * Generate |outlen| bytes into the buffer at |out|. Reseed if we need
562 * to or if |prediction_resistance| is set. Additional input can be
563 * sent in |adin| and |adinlen|.
565 * Requires that drbg->lock is already locked for write, if non-null.
567 * Returns 1 on success, 0 on failure.
570 int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
571 int prediction_resistance,
572 const unsigned char *adin, size_t adinlen)
574 int reseed_required = 0;
576 if (drbg->state != DRBG_READY) {
577 /* try to recover from previous errors */
578 rand_drbg_restart(drbg, NULL, 0, 0);
580 if (drbg->state == DRBG_ERROR) {
581 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_IN_ERROR_STATE);
584 if (drbg->state == DRBG_UNINITIALISED) {
585 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_NOT_INSTANTIATED);
590 if (outlen > drbg->max_request) {
591 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG);
594 if (adinlen > drbg->max_adinlen) {
595 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_ADDITIONAL_INPUT_TOO_LONG);
599 if (drbg->fork_count != rand_fork_count) {
600 drbg->fork_count = rand_fork_count;
604 if (drbg->reseed_interval > 0) {
605 if (drbg->generate_counter >= drbg->reseed_interval)
608 if (drbg->reseed_time_interval > 0) {
609 time_t now = time(NULL);
610 if (now < drbg->reseed_time
611 || now - drbg->reseed_time >= drbg->reseed_time_interval)
614 if (drbg->reseed_counter > 0 && drbg->parent != NULL) {
615 if (drbg->reseed_counter != drbg->parent->reseed_counter)
619 if (reseed_required || prediction_resistance) {
620 if (!RAND_DRBG_reseed(drbg, adin, adinlen, prediction_resistance)) {
621 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_RESEED_ERROR);
628 if (!drbg->meth->generate(drbg, out, outlen, adin, adinlen)) {
629 drbg->state = DRBG_ERROR;
630 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_GENERATE_ERROR);
634 drbg->generate_counter++;
640 * Generates |outlen| random bytes and stores them in |out|. It will
641 * using the given |drbg| to generate the bytes.
643 * Requires that drbg->lock is already locked for write, if non-null.
645 * Returns 1 on success 0 on failure.
647 int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen)
649 unsigned char *additional = NULL;
650 size_t additional_len;
654 additional_len = rand_drbg_get_additional_data(&additional, drbg->max_adinlen);
656 for ( ; outlen > 0; outlen -= chunk, out += chunk) {
658 if (chunk > drbg->max_request)
659 chunk = drbg->max_request;
660 ret = RAND_DRBG_generate(drbg, out, chunk, 0, additional, additional_len);
667 if (additional_len != 0)
668 OPENSSL_secure_clear_free(additional, additional_len);
674 * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
676 * Setting the callbacks is allowed only if the drbg has not been
677 * initialized yet. Otherwise, the operation will fail.
679 * Returns 1 on success, 0 on failure.
681 int RAND_DRBG_set_callbacks(RAND_DRBG *drbg,
682 RAND_DRBG_get_entropy_fn get_entropy,
683 RAND_DRBG_cleanup_entropy_fn cleanup_entropy,
684 RAND_DRBG_get_nonce_fn get_nonce,
685 RAND_DRBG_cleanup_nonce_fn cleanup_nonce)
687 if (drbg->state != DRBG_UNINITIALISED)
689 drbg->get_entropy = get_entropy;
690 drbg->cleanup_entropy = cleanup_entropy;
691 drbg->get_nonce = get_nonce;
692 drbg->cleanup_nonce = cleanup_nonce;
697 * Set the reseed interval.
699 * The drbg will reseed automatically whenever the number of generate
700 * requests exceeds the given reseed interval. If the reseed interval
701 * is 0, then this feature is disabled.
703 * Returns 1 on success, 0 on failure.
705 int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval)
707 if (interval > MAX_RESEED_INTERVAL)
709 drbg->reseed_interval = interval;
714 * Set the reseed time interval.
716 * The drbg will reseed automatically whenever the time elapsed since
717 * the last reseeding exceeds the given reseed time interval. For safety,
718 * a reseeding will also occur if the clock has been reset to a smaller
721 * Returns 1 on success, 0 on failure.
723 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval)
725 if (interval > MAX_RESEED_TIME_INTERVAL)
727 drbg->reseed_time_interval = interval;
732 * Set the default values for reseed (time) intervals of new DRBG instances
734 * The default values can be set independently for master DRBG instances
735 * (without a parent) and slave DRBG instances (with parent).
737 * Returns 1 on success, 0 on failure.
740 int RAND_DRBG_set_reseed_defaults(
741 unsigned int _master_reseed_interval,
742 unsigned int _slave_reseed_interval,
743 time_t _master_reseed_time_interval,
744 time_t _slave_reseed_time_interval
747 if (_master_reseed_interval > MAX_RESEED_INTERVAL
748 || _slave_reseed_interval > MAX_RESEED_INTERVAL)
751 if (_master_reseed_time_interval > MAX_RESEED_TIME_INTERVAL
752 || _slave_reseed_time_interval > MAX_RESEED_TIME_INTERVAL)
755 master_reseed_interval = _master_reseed_interval;
756 slave_reseed_interval = _slave_reseed_interval;
758 master_reseed_time_interval = _master_reseed_time_interval;
759 slave_reseed_time_interval = _slave_reseed_time_interval;
765 * Locks the given drbg. Locking a drbg which does not have locking
766 * enabled is considered a successful no-op.
768 * Returns 1 on success, 0 on failure.
770 int rand_drbg_lock(RAND_DRBG *drbg)
772 if (drbg->lock != NULL)
773 return CRYPTO_THREAD_write_lock(drbg->lock);
779 * Unlocks the given drbg. Unlocking a drbg which does not have locking
780 * enabled is considered a successful no-op.
782 * Returns 1 on success, 0 on failure.
784 int rand_drbg_unlock(RAND_DRBG *drbg)
786 if (drbg->lock != NULL)
787 return CRYPTO_THREAD_unlock(drbg->lock);
793 * Enables locking for the given drbg
795 * Locking can only be enabled if the random generator
796 * is in the uninitialized state.
798 * Returns 1 on success, 0 on failure.
800 int rand_drbg_enable_locking(RAND_DRBG *drbg)
802 if (drbg->state != DRBG_UNINITIALISED) {
803 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
804 RAND_R_DRBG_ALREADY_INITIALIZED);
808 if (drbg->lock == NULL) {
809 if (drbg->parent != NULL && drbg->parent->lock == NULL) {
810 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
811 RAND_R_PARENT_LOCKING_NOT_ENABLED);
815 drbg->lock = CRYPTO_THREAD_lock_new();
816 if (drbg->lock == NULL) {
817 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
818 RAND_R_FAILED_TO_CREATE_LOCK);
827 * Get and set the EXDATA
829 int RAND_DRBG_set_ex_data(RAND_DRBG *drbg, int idx, void *arg)
831 return CRYPTO_set_ex_data(&drbg->ex_data, idx, arg);
834 void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx)
836 return CRYPTO_get_ex_data(&drbg->ex_data, idx);
841 * The following functions provide a RAND_METHOD that works on the
842 * global DRBG. They lock.
846 * Allocates a new global DRBG on the secure heap (if enabled) and
847 * initializes it with default settings.
849 * Returns a pointer to the new DRBG instance on success, NULL on failure.
851 static RAND_DRBG *drbg_setup(RAND_DRBG *parent)
855 drbg = RAND_DRBG_secure_new(rand_drbg_type, rand_drbg_flags, parent);
859 /* Only the master DRBG needs to have a lock */
860 if (parent == NULL && rand_drbg_enable_locking(drbg) == 0)
863 /* enable seed propagation */
864 drbg->reseed_counter = 1;
867 * Ignore instantiation error to support just-in-time instantiation.
869 * The state of the drbg will be checked in RAND_DRBG_generate() and
870 * an automatic recovery is attempted.
872 (void)RAND_DRBG_instantiate(drbg,
873 (const unsigned char *) ossl_pers_string,
874 sizeof(ossl_pers_string) - 1);
878 RAND_DRBG_free(drbg);
883 * Initialize the global DRBGs on first use.
884 * Returns 1 on success, 0 on failure.
886 DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init)
891 * ensure that libcrypto is initialized, otherwise the
892 * DRBG locks are not cleaned up properly
894 if (!OPENSSL_init_crypto(0, NULL))
897 ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
899 master_drbg = drbg_setup(NULL);
901 ret &= CRYPTO_THREAD_init_local(&private_drbg, NULL);
902 ret &= CRYPTO_THREAD_init_local(&public_drbg, NULL);
904 if (master_drbg == NULL || ret == 0)
910 /* Clean up the global DRBGs before exit */
911 void rand_drbg_cleanup_int(void)
913 RAND_DRBG_free(master_drbg);
916 CRYPTO_THREAD_cleanup_local(&private_drbg);
917 CRYPTO_THREAD_cleanup_local(&public_drbg);
920 void drbg_delete_thread_state()
924 drbg = CRYPTO_THREAD_get_local(&public_drbg);
925 RAND_DRBG_free(drbg);
927 drbg = CRYPTO_THREAD_get_local(&private_drbg);
928 RAND_DRBG_free(drbg);
931 /* Implements the default OpenSSL RAND_bytes() method */
932 static int drbg_bytes(unsigned char *out, int count)
935 RAND_DRBG *drbg = RAND_DRBG_get0_public();
940 ret = RAND_DRBG_bytes(drbg, out, count);
945 /* Implements the default OpenSSL RAND_add() method */
946 static int drbg_add(const void *buf, int num, double randomness)
949 RAND_DRBG *drbg = RAND_DRBG_get0_master();
954 if (num < 0 || randomness < 0.0)
957 if (randomness > (double)drbg->max_entropylen) {
959 * The purpose of this check is to bound |randomness| by a
960 * relatively small value in order to prevent an integer
961 * overflow when multiplying by 8 in the rand_drbg_restart()
967 rand_drbg_lock(drbg);
968 ret = rand_drbg_restart(drbg, buf,
969 (size_t)(unsigned int)num,
970 (size_t)(8*randomness));
971 rand_drbg_unlock(drbg);
976 /* Implements the default OpenSSL RAND_seed() method */
977 static int drbg_seed(const void *buf, int num)
979 return drbg_add(buf, num, num);
982 /* Implements the default OpenSSL RAND_status() method */
983 static int drbg_status(void)
986 RAND_DRBG *drbg = RAND_DRBG_get0_master();
991 rand_drbg_lock(drbg);
992 ret = drbg->state == DRBG_READY ? 1 : 0;
993 rand_drbg_unlock(drbg);
998 * Get the master DRBG.
999 * Returns pointer to the DRBG on success, NULL on failure.
1002 RAND_DRBG *RAND_DRBG_get0_master(void)
1004 if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
1011 * Get the public DRBG.
1012 * Returns pointer to the DRBG on success, NULL on failure.
1014 RAND_DRBG *RAND_DRBG_get0_public(void)
1018 if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
1021 drbg = CRYPTO_THREAD_get_local(&public_drbg);
1023 ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
1024 drbg = drbg_setup(master_drbg);
1025 CRYPTO_THREAD_set_local(&public_drbg, drbg);
1031 * Get the private DRBG.
1032 * Returns pointer to the DRBG on success, NULL on failure.
1034 RAND_DRBG *RAND_DRBG_get0_private(void)
1038 if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
1041 drbg = CRYPTO_THREAD_get_local(&private_drbg);
1043 ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND);
1044 drbg = drbg_setup(master_drbg);
1045 CRYPTO_THREAD_set_local(&private_drbg, drbg);
1050 RAND_METHOD rand_meth = {
1059 RAND_METHOD *RAND_OpenSSL(void)