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"
19 * Support framework for NIST SP 800-90A DRBG, AES-CTR mode.
20 * The RAND_DRBG is OpenSSL's pointer to an instance of the DRBG.
22 * The OpenSSL model is to have new and free functions, and that new
23 * does all initialization. That is not the NIST model, which has
24 * instantiation and un-instantiate, and re-use within a new/free
25 * lifecycle. (No doubt this comes from the desire to support hardware
26 * DRBG, where allocation of resources on something like an HSM is
27 * a much bigger deal than just re-setting an allocated resource.)
31 * THE THREE SHARED DRBGs
33 * There are three shared DRBGs (master, public and private), which are
34 * accessed concurrently by all threads.
38 * Not used directly by the application, only for reseeding the two other
39 * DRBGs. It reseeds itself by pulling either randomness from os entropy
40 * sources or by consuming randomnes which was added by RAND_add()
42 static RAND_DRBG *drbg_master;
46 * Used by default for generating random bytes using RAND_bytes().
48 static RAND_DRBG *drbg_public;
52 * Used by default for generating private keys using RAND_priv_bytes()
54 static RAND_DRBG *drbg_private;
58 * In addition there are DRBGs, which are not shared, but used only by a
59 * single thread at every time, for example the DRBGs which are owned by
60 * an SSL context. All DRBGs are organized in a hierarchical fashion
61 * with the <master> DRBG as root.
63 * This gives the following overall picture:
65 * <os entropy sources>
67 * RAND_add() ==> <master> \
68 * / \ | shared DRBGs (with locking)
69 * <public> <private> /
71 * <ssl> owned by an SSL context
75 * Before satisfying a generate request, a DRBG reseeds itself automatically,
76 * if one of the following two conditions holds:
78 * - the number of generate requests since the last reseeding exceeds a
79 * certain threshold, the so called |reseed_interval|. This behaviour
80 * can be disabled by setting the |reseed_interval| to 0.
82 * - the time elapsed since the last reseeding exceeds a certain time
83 * interval, the so called |reseed_time_interval|. This behaviour
84 * can be disabled by setting the |reseed_time_interval| to 0.
88 * For the three shared DRBGs (and only for these) there is another way to
89 * reseed them manually by calling RAND_seed() (or RAND_add() with a positive
90 * |randomness| argument). This will immediately reseed the <master> DRBG.
91 * The <public> and <private> DRBG will detect this on their next generate
92 * call and reseed, pulling randomness from <master>.
96 * The three shared DRBGs are intended to be used concurrently, so they
97 * support locking. The RAND methods take the locks automatically, so using
98 * the RAND api (in particular RAND_bytes() and RAND_priv_bytes()) is
99 * thread-safe. Note however that accessing the shared DRBGs directly via
100 * the RAND_DRBG interface is *not* thread-safe.
102 * All other DRBG instances don't support locking, because they are
103 * intendended to be used by a single thread. Instead of accessing a single
104 * DRBG instance concurrently from different threads, it is recommended to
105 * instantiate a separate DRBG instance per thread. Using the same shared
106 * DRBG (preferrably the public DRBG) as parent of DRBG instances on
107 * different threads is safe.
111 /* NIST SP 800-90A DRBG recommends the use of a personalization string. */
112 static const char ossl_pers_string[] = "OpenSSL NIST SP 800-90A DRBG";
114 static CRYPTO_ONCE rand_drbg_init = CRYPTO_ONCE_STATIC_INIT;
116 static RAND_DRBG *drbg_setup(RAND_DRBG *parent);
118 static RAND_DRBG *rand_drbg_new(int secure,
124 * Set/initialize |drbg| to be of type |nid|, with optional |flags|.
126 * Returns 1 on success, 0 on failure.
128 int RAND_DRBG_set(RAND_DRBG *drbg, int nid, unsigned int flags)
132 drbg->state = DRBG_UNINITIALISED;
138 RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE);
141 /* Uninitialized; that's okay. */
143 case NID_aes_128_ctr:
144 case NID_aes_192_ctr:
145 case NID_aes_256_ctr:
146 ret = drbg_ctr_init(drbg);
151 RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG);
156 * Allocate memory and initialize a new DRBG. The DRBG is allocated on
157 * the secure heap if |secure| is nonzero and the secure heap is enabled.
158 * The |parent|, if not NULL, will be used as random source for reseeding.
160 * Returns a pointer to the new DRBG instance on success, NULL on failure.
162 static RAND_DRBG *rand_drbg_new(int secure,
167 RAND_DRBG *drbg = secure ?
168 OPENSSL_secure_zalloc(sizeof(*drbg)) : OPENSSL_zalloc(sizeof(*drbg));
171 RANDerr(RAND_F_RAND_DRBG_NEW, ERR_R_MALLOC_FAILURE);
175 drbg->secure = secure && CRYPTO_secure_allocated(drbg);
176 drbg->fork_count = rand_fork_count;
177 drbg->parent = parent;
178 if (RAND_DRBG_set(drbg, type, flags) == 0)
181 if (parent != NULL && drbg->strength > parent->strength) {
183 * We currently don't support the algorithm from NIST SP 800-90C
184 * 10.1.2 to use a weaker DRBG as source
186 RANDerr(RAND_F_RAND_DRBG_NEW, RAND_R_PARENT_STRENGTH_TOO_WEAK);
190 if (!RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy,
191 rand_drbg_cleanup_entropy,
199 OPENSSL_secure_free(drbg);
206 RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent)
208 return rand_drbg_new(0, type, flags, parent);
211 RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent)
213 return rand_drbg_new(1, type, flags, parent);
217 * Uninstantiate |drbg| and free all memory.
219 void RAND_DRBG_free(RAND_DRBG *drbg)
224 if (drbg->meth != NULL)
225 drbg->meth->uninstantiate(drbg);
226 CRYPTO_THREAD_lock_free(drbg->lock);
227 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data);
230 OPENSSL_secure_clear_free(drbg, sizeof(*drbg));
232 OPENSSL_clear_free(drbg, sizeof(*drbg));
236 * Instantiate |drbg|, after it has been initialized. Use |pers| and
237 * |perslen| as prediction-resistance input.
239 * Requires that drbg->lock is already locked for write, if non-null.
241 * Returns 1 on success, 0 on failure.
243 int RAND_DRBG_instantiate(RAND_DRBG *drbg,
244 const unsigned char *pers, size_t perslen)
246 unsigned char *nonce = NULL, *entropy = NULL;
247 size_t noncelen = 0, entropylen = 0;
249 if (perslen > drbg->max_perslen) {
250 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
251 RAND_R_PERSONALISATION_STRING_TOO_LONG);
255 if (drbg->meth == NULL)
257 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
258 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
262 if (drbg->state != DRBG_UNINITIALISED) {
263 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
264 drbg->state == DRBG_ERROR ? RAND_R_IN_ERROR_STATE
265 : RAND_R_ALREADY_INSTANTIATED);
269 drbg->state = DRBG_ERROR;
270 if (drbg->get_entropy != NULL)
271 entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength,
272 drbg->min_entropylen, drbg->max_entropylen);
273 if (entropylen < drbg->min_entropylen
274 || entropylen > drbg->max_entropylen) {
275 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_ENTROPY);
279 if (drbg->max_noncelen > 0 && drbg->get_nonce != NULL) {
280 noncelen = drbg->get_nonce(drbg, &nonce, drbg->strength / 2,
281 drbg->min_noncelen, drbg->max_noncelen);
282 if (noncelen < drbg->min_noncelen || noncelen > drbg->max_noncelen) {
283 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
284 RAND_R_ERROR_RETRIEVING_NONCE);
289 if (!drbg->meth->instantiate(drbg, entropy, entropylen,
290 nonce, noncelen, pers, perslen)) {
291 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_INSTANTIATING_DRBG);
295 drbg->state = DRBG_READY;
296 drbg->generate_counter = 0;
297 drbg->reseed_time = time(NULL);
298 if (drbg->reseed_counter > 0) {
299 if (drbg->parent == NULL)
300 drbg->reseed_counter++;
302 drbg->reseed_counter = drbg->parent->reseed_counter;
306 if (entropy != NULL && drbg->cleanup_entropy != NULL)
307 drbg->cleanup_entropy(drbg, entropy, entropylen);
308 if (nonce != NULL && drbg->cleanup_nonce!= NULL )
309 drbg->cleanup_nonce(drbg, nonce, noncelen);
310 if (drbg->pool != NULL) {
311 if (drbg->state == DRBG_READY) {
312 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE,
313 RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED);
314 drbg->state = DRBG_ERROR;
316 RAND_POOL_free(drbg->pool);
319 if (drbg->state == DRBG_READY)
325 * Uninstantiate |drbg|. Must be instantiated before it can be used.
327 * Requires that drbg->lock is already locked for write, if non-null.
329 * Returns 1 on success, 0 on failure.
331 int RAND_DRBG_uninstantiate(RAND_DRBG *drbg)
333 if (drbg->meth == NULL)
335 RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE,
336 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
340 /* Clear the entire drbg->ctr struct, then reset some important
341 * members of the drbg->ctr struct (e.g. keysize, df_ks) to their
344 drbg->meth->uninstantiate(drbg);
345 return RAND_DRBG_set(drbg, drbg->nid, drbg->flags);
349 * Reseed |drbg|, mixing in the specified data
351 * Requires that drbg->lock is already locked for write, if non-null.
353 * Returns 1 on success, 0 on failure.
355 int RAND_DRBG_reseed(RAND_DRBG *drbg,
356 const unsigned char *adin, size_t adinlen)
358 unsigned char *entropy = NULL;
359 size_t entropylen = 0;
361 if (drbg->state == DRBG_ERROR) {
362 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_IN_ERROR_STATE);
365 if (drbg->state == DRBG_UNINITIALISED) {
366 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_NOT_INSTANTIATED);
372 else if (adinlen > drbg->max_adinlen) {
373 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ADDITIONAL_INPUT_TOO_LONG);
377 drbg->state = DRBG_ERROR;
378 if (drbg->get_entropy != NULL)
379 entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength,
380 drbg->min_entropylen, drbg->max_entropylen);
381 if (entropylen < drbg->min_entropylen
382 || entropylen > drbg->max_entropylen) {
383 RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ERROR_RETRIEVING_ENTROPY);
387 if (!drbg->meth->reseed(drbg, entropy, entropylen, adin, adinlen))
390 drbg->state = DRBG_READY;
391 drbg->generate_counter = 0;
392 drbg->reseed_time = time(NULL);
393 if (drbg->reseed_counter > 0) {
394 if (drbg->parent == NULL)
395 drbg->reseed_counter++;
397 drbg->reseed_counter = drbg->parent->reseed_counter;
401 if (entropy != NULL && drbg->cleanup_entropy != NULL)
402 drbg->cleanup_entropy(drbg, entropy, entropylen);
403 if (drbg->state == DRBG_READY)
409 * Restart |drbg|, using the specified entropy or additional input
411 * Tries its best to get the drbg instantiated by all means,
412 * regardless of its current state.
414 * Optionally, a |buffer| of |len| random bytes can be passed,
415 * which is assumed to contain at least |entropy| bits of entropy.
417 * If |entropy| > 0, the buffer content is used as entropy input.
419 * If |entropy| == 0, the buffer content is used as additional input
421 * Returns 1 on success, 0 on failure.
423 * This function is used internally only.
425 int rand_drbg_restart(RAND_DRBG *drbg,
426 const unsigned char *buffer, size_t len, size_t entropy)
429 const unsigned char *adin = NULL;
432 if (drbg->pool != NULL) {
433 RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
434 RAND_POOL_free(drbg->pool);
438 if (buffer != NULL) {
440 if (drbg->max_entropylen < len) {
441 RANDerr(RAND_F_RAND_DRBG_RESTART,
442 RAND_R_ENTROPY_INPUT_TOO_LONG);
446 if (entropy > 8 * len) {
447 RANDerr(RAND_F_RAND_DRBG_RESTART, RAND_R_ENTROPY_OUT_OF_RANGE);
451 /* will be picked up by the rand_drbg_get_entropy() callback */
452 drbg->pool = RAND_POOL_new(entropy, len, len);
453 if (drbg->pool == NULL)
456 RAND_POOL_add(drbg->pool, buffer, len, entropy);
458 if (drbg->max_adinlen < len) {
459 RANDerr(RAND_F_RAND_DRBG_RESTART,
460 RAND_R_ADDITIONAL_INPUT_TOO_LONG);
468 /* repair error state */
469 if (drbg->state == DRBG_ERROR)
470 RAND_DRBG_uninstantiate(drbg);
472 /* repair uninitialized state */
473 if (drbg->state == DRBG_UNINITIALISED) {
474 /* reinstantiate drbg */
475 RAND_DRBG_instantiate(drbg,
476 (const unsigned char *) ossl_pers_string,
477 sizeof(ossl_pers_string) - 1);
478 /* already reseeded. prevent second reseeding below */
479 reseeded = (drbg->state == DRBG_READY);
482 /* refresh current state if entropy or additional input has been provided */
483 if (drbg->state == DRBG_READY) {
486 * mix in additional input without reseeding
488 * Similar to RAND_DRBG_reseed(), but the provided additional
489 * data |adin| is mixed into the current state without pulling
490 * entropy from the trusted entropy source using get_entropy().
491 * This is not a reseeding in the strict sense of NIST SP 800-90A.
493 drbg->meth->reseed(drbg, adin, adinlen, NULL, 0);
494 } else if (reseeded == 0) {
495 /* do a full reseeding if it has not been done yet above */
496 RAND_DRBG_reseed(drbg, NULL, 0);
500 /* check whether a given entropy pool was cleared properly during reseed */
501 if (drbg->pool != NULL) {
502 drbg->state = DRBG_ERROR;
503 RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR);
504 RAND_POOL_free(drbg->pool);
509 return drbg->state == DRBG_READY;
513 * Generate |outlen| bytes into the buffer at |out|. Reseed if we need
514 * to or if |prediction_resistance| is set. Additional input can be
515 * sent in |adin| and |adinlen|.
517 * Requires that drbg->lock is already locked for write, if non-null.
519 * Returns 1 on success, 0 on failure.
522 int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
523 int prediction_resistance,
524 const unsigned char *adin, size_t adinlen)
526 int reseed_required = 0;
528 if (drbg->state != DRBG_READY) {
529 /* try to recover from previous errors */
530 rand_drbg_restart(drbg, NULL, 0, 0);
532 if (drbg->state == DRBG_ERROR) {
533 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_IN_ERROR_STATE);
536 if (drbg->state == DRBG_UNINITIALISED) {
537 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_NOT_INSTANTIATED);
542 if (outlen > drbg->max_request) {
543 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG);
546 if (adinlen > drbg->max_adinlen) {
547 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_ADDITIONAL_INPUT_TOO_LONG);
551 if (drbg->fork_count != rand_fork_count) {
552 drbg->fork_count = rand_fork_count;
556 if (drbg->reseed_interval > 0) {
557 if (drbg->generate_counter >= drbg->reseed_interval)
560 if (drbg->reseed_time_interval > 0) {
561 time_t now = time(NULL);
562 if (now < drbg->reseed_time
563 || now - drbg->reseed_time >= drbg->reseed_time_interval)
566 if (drbg->reseed_counter > 0 && drbg->parent != NULL) {
567 if (drbg->reseed_counter != drbg->parent->reseed_counter)
571 if (reseed_required || prediction_resistance) {
572 if (!RAND_DRBG_reseed(drbg, adin, adinlen)) {
573 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_RESEED_ERROR);
580 if (!drbg->meth->generate(drbg, out, outlen, adin, adinlen)) {
581 drbg->state = DRBG_ERROR;
582 RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_GENERATE_ERROR);
586 drbg->generate_counter++;
592 * Generates |outlen| random bytes and stores them in |out|. It will
593 * using the given |drbg| to generate the bytes.
595 * Requires that drbg->lock is already locked for write, if non-null.
597 * Returns 1 on success 0 on failure.
599 int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen)
601 unsigned char *additional = NULL;
602 size_t additional_len;
606 additional_len = rand_drbg_get_additional_data(&additional, drbg->max_adinlen);
608 for ( ; outlen > 0; outlen -= chunk, out += chunk) {
610 if (chunk > drbg->max_request)
611 chunk = drbg->max_request;
612 ret = RAND_DRBG_generate(drbg, out, chunk, 0, additional, additional_len);
619 if (additional_len != 0)
620 OPENSSL_secure_clear_free(additional, additional_len);
626 * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
628 * In the following, the signature and the semantics of the
629 * get_entropy() and cleanup_entropy() callbacks are explained.
633 * size_t get_entropy(RAND_DRBG *ctx,
634 * unsigned char **pout,
636 * size_t min_len, size_t max_len);
638 * This is a request to allocate and fill a buffer of size
639 * |min_len| <= size <= |max_len| (in bytes) which contains
640 * at least |entropy| bits of randomness. The buffer's address is
641 * to be returned in |*pout| and the number of collected
642 * randomness bytes (which may be less than the allocated size
643 * of the buffer) as return value.
645 * If the callback fails to acquire at least |entropy| bits of
646 * randomness, it shall return a buffer length of 0.
650 * void cleanup_entropy(RAND_DRBG *ctx,
651 * unsigned char *out, size_t outlen);
653 * A request to clear and free the buffer allocated by get_entropy().
654 * The values |out| and |outlen| are expected to be the random buffer's
655 * address and length, as returned by the get_entropy() callback.
657 * GET_NONCE, CLEANUP_NONCE
659 * Signature and semantics of the get_nonce() and cleanup_nonce()
660 * callbacks are analogous to get_entropy() and cleanup_entropy().
661 * Currently, the nonce is used only for the known answer tests.
663 int RAND_DRBG_set_callbacks(RAND_DRBG *drbg,
664 RAND_DRBG_get_entropy_fn get_entropy,
665 RAND_DRBG_cleanup_entropy_fn cleanup_entropy,
666 RAND_DRBG_get_nonce_fn get_nonce,
667 RAND_DRBG_cleanup_nonce_fn cleanup_nonce)
669 if (drbg->state != DRBG_UNINITIALISED)
671 drbg->get_entropy = get_entropy;
672 drbg->cleanup_entropy = cleanup_entropy;
673 drbg->get_nonce = get_nonce;
674 drbg->cleanup_nonce = cleanup_nonce;
679 * Set the reseed interval.
681 * The drbg will reseed automatically whenever the number of generate
682 * requests exceeds the given reseed interval. If the reseed interval
683 * is 0, then this feature is disabled.
685 * Returns 1 on success, 0 on failure.
687 int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval)
689 if (interval > MAX_RESEED_INTERVAL)
691 drbg->reseed_interval = interval;
696 * Set the reseed time interval.
698 * The drbg will reseed automatically whenever the time elapsed since
699 * the last reseeding exceeds the given reseed time interval. For safety,
700 * a reseeding will also occur if the clock has been reset to a smaller
703 * Returns 1 on success, 0 on failure.
705 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval)
707 if (interval > MAX_RESEED_TIME_INTERVAL)
709 drbg->reseed_time_interval = interval;
715 * Locks the given drbg. Locking a drbg which does not have locking
716 * enabled is considered a successful no-op.
718 * Returns 1 on success, 0 on failure.
720 int rand_drbg_lock(RAND_DRBG *drbg)
722 if (drbg->lock != NULL)
723 return CRYPTO_THREAD_write_lock(drbg->lock);
729 * Unlocks the given drbg. Unlocking a drbg which does not have locking
730 * enabled is considered a successful no-op.
732 * Returns 1 on success, 0 on failure.
734 int rand_drbg_unlock(RAND_DRBG *drbg)
736 if (drbg->lock != NULL)
737 return CRYPTO_THREAD_unlock(drbg->lock);
743 * Enables locking for the given drbg
745 * Locking can only be enabled if the random generator
746 * is in the uninitialized state.
748 * Returns 1 on success, 0 on failure.
750 int rand_drbg_enable_locking(RAND_DRBG *drbg)
752 if (drbg->state != DRBG_UNINITIALISED) {
753 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
754 RAND_R_DRBG_ALREADY_INITIALIZED);
758 if (drbg->lock == NULL) {
759 if (drbg->parent != NULL && drbg->parent->lock == NULL) {
760 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
761 RAND_R_PARENT_LOCKING_NOT_ENABLED);
765 drbg->lock = CRYPTO_THREAD_lock_new();
766 if (drbg->lock == NULL) {
767 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING,
768 RAND_R_FAILED_TO_CREATE_LOCK);
777 * Get and set the EXDATA
779 int RAND_DRBG_set_ex_data(RAND_DRBG *drbg, int idx, void *arg)
781 return CRYPTO_set_ex_data(&drbg->ex_data, idx, arg);
784 void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx)
786 return CRYPTO_get_ex_data(&drbg->ex_data, idx);
791 * The following functions provide a RAND_METHOD that works on the
792 * global DRBG. They lock.
796 * Allocates a new global DRBG on the secure heap (if enabled) and
797 * initializes it with default settings.
799 * Returns a pointer to the new DRBG instance on success, NULL on failure.
801 static RAND_DRBG *drbg_setup(RAND_DRBG *parent)
805 drbg = RAND_DRBG_secure_new(RAND_DRBG_NID, 0, parent);
809 if (rand_drbg_enable_locking(drbg) == 0)
812 if (parent == NULL) {
813 drbg->reseed_interval = MASTER_RESEED_INTERVAL;
814 drbg->reseed_time_interval = MASTER_RESEED_TIME_INTERVAL;
816 drbg->reseed_interval = SLAVE_RESEED_INTERVAL;
817 drbg->reseed_time_interval = SLAVE_RESEED_TIME_INTERVAL;
820 /* enable seed propagation */
821 drbg->reseed_counter = 1;
824 * Ignore instantiation error so support just-in-time instantiation.
826 * The state of the drbg will be checked in RAND_DRBG_generate() and
827 * an automatic recovery is attempted.
829 RAND_DRBG_instantiate(drbg,
830 (const unsigned char *) ossl_pers_string,
831 sizeof(ossl_pers_string) - 1);
835 RAND_DRBG_free(drbg);
840 * Initialize the global DRBGs on first use.
841 * Returns 1 on success, 0 on failure.
843 DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init)
846 * ensure that libcrypto is initialized, otherwise the
847 * DRBG locks are not cleaned up properly
849 if (!OPENSSL_init_crypto(0, NULL))
852 drbg_master = drbg_setup(NULL);
853 drbg_public = drbg_setup(drbg_master);
854 drbg_private = drbg_setup(drbg_master);
856 if (drbg_master == NULL || drbg_public == NULL || drbg_private == NULL)
862 /* Clean up the global DRBGs before exit */
863 void rand_drbg_cleanup_int(void)
865 RAND_DRBG_free(drbg_private);
866 RAND_DRBG_free(drbg_public);
867 RAND_DRBG_free(drbg_master);
869 drbg_private = drbg_public = drbg_master = NULL;
872 /* Implements the default OpenSSL RAND_bytes() method */
873 static int drbg_bytes(unsigned char *out, int count)
876 RAND_DRBG *drbg = RAND_DRBG_get0_public();
881 rand_drbg_lock(drbg);
882 ret = RAND_DRBG_bytes(drbg, out, count);
883 rand_drbg_unlock(drbg);
888 /* Implements the default OpenSSL RAND_add() method */
889 static int drbg_add(const void *buf, int num, double randomness)
892 RAND_DRBG *drbg = RAND_DRBG_get0_master();
897 if (num < 0 || randomness < 0.0)
900 if (randomness > (double)drbg->max_entropylen) {
902 * The purpose of this check is to bound |randomness| by a
903 * relatively small value in order to prevent an integer
904 * overflow when multiplying by 8 in the rand_drbg_restart()
910 rand_drbg_lock(drbg);
911 ret = rand_drbg_restart(drbg, buf,
912 (size_t)(unsigned int)num,
913 (size_t)(8*randomness));
914 rand_drbg_unlock(drbg);
919 /* Implements the default OpenSSL RAND_seed() method */
920 static int drbg_seed(const void *buf, int num)
922 return drbg_add(buf, num, num);
925 /* Implements the default OpenSSL RAND_status() method */
926 static int drbg_status(void)
929 RAND_DRBG *drbg = RAND_DRBG_get0_master();
934 rand_drbg_lock(drbg);
935 ret = drbg->state == DRBG_READY ? 1 : 0;
936 rand_drbg_unlock(drbg);
941 * Get the master DRBG.
942 * Returns pointer to the DRBG on success, NULL on failure.
945 RAND_DRBG *RAND_DRBG_get0_master(void)
947 if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
954 * Get the public DRBG.
955 * Returns pointer to the DRBG on success, NULL on failure.
957 RAND_DRBG *RAND_DRBG_get0_public(void)
959 if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
966 * Get the private DRBG.
967 * Returns pointer to the DRBG on success, NULL on failure.
969 RAND_DRBG *RAND_DRBG_get0_private(void)
971 if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init))
977 RAND_METHOD rand_meth = {
986 RAND_METHOD *RAND_OpenSSL(void)