2 * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (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
12 #include "internal/cryptlib.h"
13 #include <openssl/opensslconf.h>
14 #include "crypto/rand.h"
15 #include <openssl/engine.h>
16 #include "internal/thread_once.h"
17 #include "rand_local.h"
21 # ifndef OPENSSL_NO_ENGINE
22 /* non-NULL if default_RAND_meth is ENGINE-provided */
23 static ENGINE *funct_ref;
24 static CRYPTO_RWLOCK *rand_engine_lock;
26 static CRYPTO_RWLOCK *rand_meth_lock;
27 static const RAND_METHOD *default_RAND_meth;
28 static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT;
30 static int rand_inited = 0;
31 #endif /* FIPS_MODE */
33 #ifdef OPENSSL_RAND_SEED_RDTSC
35 * IMPORTANT NOTE: It is not currently possible to use this code
36 * because we are not sure about the amount of randomness it provides.
37 * Some SP900 tests have been run, but there is internal skepticism.
38 * So for now this code is not used.
40 # error "RDTSC enabled? Should not be possible!"
43 * Acquire entropy from high-speed clock
45 * Since we get some randomness from the low-order bits of the
46 * high-speed clock, it can help.
48 * Returns the total entropy count, if it exceeds the requested
49 * entropy count. Otherwise, returns an entropy count of 0.
51 size_t rand_acquire_entropy_from_tsc(RAND_POOL *pool)
56 if ((OPENSSL_ia32cap_P[0] & (1 << 4)) != 0) {
57 for (i = 0; i < TSC_READ_COUNT; i++) {
58 c = (unsigned char)(OPENSSL_rdtsc() & 0xFF);
59 rand_pool_add(pool, &c, 1, 4);
62 return rand_pool_entropy_available(pool);
66 #ifdef OPENSSL_RAND_SEED_RDCPU
67 size_t OPENSSL_ia32_rdseed_bytes(unsigned char *buf, size_t len);
68 size_t OPENSSL_ia32_rdrand_bytes(unsigned char *buf, size_t len);
71 * Acquire entropy using Intel-specific cpu instructions
73 * Uses the RDSEED instruction if available, otherwise uses
74 * RDRAND if available.
76 * For the differences between RDSEED and RDRAND, and why RDSEED
77 * is the preferred choice, see https://goo.gl/oK3KcN
79 * Returns the total entropy count, if it exceeds the requested
80 * entropy count. Otherwise, returns an entropy count of 0.
82 size_t rand_acquire_entropy_from_cpu(RAND_POOL *pool)
85 unsigned char *buffer;
87 bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
88 if (bytes_needed > 0) {
89 buffer = rand_pool_add_begin(pool, bytes_needed);
92 /* Whichever comes first, use RDSEED, RDRAND or nothing */
93 if ((OPENSSL_ia32cap_P[2] & (1 << 18)) != 0) {
94 if (OPENSSL_ia32_rdseed_bytes(buffer, bytes_needed)
96 rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed);
98 } else if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) {
99 if (OPENSSL_ia32_rdrand_bytes(buffer, bytes_needed)
101 rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed);
104 rand_pool_add_end(pool, 0, 0);
109 return rand_pool_entropy_available(pool);
115 * Implements the get_entropy() callback (see RAND_DRBG_set_callbacks())
117 * If the DRBG has a parent, then the required amount of entropy input
118 * is fetched using the parent's RAND_DRBG_generate().
120 * Otherwise, the entropy is polled from the system entropy sources
121 * using rand_pool_acquire_entropy().
123 * If a random pool has been added to the DRBG using RAND_add(), then
124 * its entropy will be used up first.
126 size_t rand_drbg_get_entropy(RAND_DRBG *drbg,
127 unsigned char **pout,
128 int entropy, size_t min_len, size_t max_len,
129 int prediction_resistance)
132 size_t entropy_available = 0;
135 if (drbg->parent != NULL && drbg->strength > drbg->parent->strength) {
137 * We currently don't support the algorithm from NIST SP 800-90C
138 * 10.1.2 to use a weaker DRBG as source
140 RANDerr(RAND_F_RAND_DRBG_GET_ENTROPY, RAND_R_PARENT_STRENGTH_TOO_WEAK);
144 if (drbg->seed_pool != NULL) {
145 pool = drbg->seed_pool;
146 pool->entropy_requested = entropy;
148 pool = rand_pool_new(entropy, drbg->secure, min_len, max_len);
153 if (drbg->parent != NULL) {
154 size_t bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
155 unsigned char *buffer = rand_pool_add_begin(pool, bytes_needed);
157 if (buffer != NULL) {
161 * Get random data from parent. Include our address as additional input,
162 * in order to provide some additional distinction between different
163 * DRBG child instances.
164 * Our lock is already held, but we need to lock our parent before
165 * generating bits from it. (Note: taking the lock will be a no-op
166 * if locking if drbg->parent->lock == NULL.)
168 rand_drbg_lock(drbg->parent);
169 if (RAND_DRBG_generate(drbg->parent,
170 buffer, bytes_needed,
171 prediction_resistance,
172 (unsigned char *)&drbg, sizeof(drbg)) != 0)
173 bytes = bytes_needed;
174 drbg->reseed_next_counter
175 = tsan_load(&drbg->parent->reseed_prop_counter);
176 rand_drbg_unlock(drbg->parent);
178 rand_pool_add_end(pool, bytes, 8 * bytes);
179 entropy_available = rand_pool_entropy_available(pool);
183 /* Get entropy by polling system entropy sources. */
184 entropy_available = rand_pool_acquire_entropy(pool);
187 if (entropy_available > 0) {
188 ret = rand_pool_length(pool);
189 *pout = rand_pool_detach(pool);
192 if (drbg->seed_pool == NULL)
193 rand_pool_free(pool);
198 * Implements the cleanup_entropy() callback (see RAND_DRBG_set_callbacks())
201 void rand_drbg_cleanup_entropy(RAND_DRBG *drbg,
202 unsigned char *out, size_t outlen)
204 if (drbg->seed_pool == NULL) {
206 OPENSSL_secure_clear_free(out, outlen);
208 OPENSSL_clear_free(out, outlen);
213 * Generate additional data that can be used for the drbg. The data does
214 * not need to contain entropy, but it's useful if it contains at least
215 * some bits that are unpredictable.
217 * Returns 0 on failure.
219 * On success it allocates a buffer at |*pout| and returns the length of
220 * the data. The buffer should get freed using OPENSSL_secure_clear_free().
222 size_t rand_drbg_get_additional_data(RAND_POOL *pool, unsigned char **pout)
226 if (rand_pool_add_additional_data(pool) == 0)
229 ret = rand_pool_length(pool);
230 *pout = rand_pool_detach(pool);
236 void rand_drbg_cleanup_additional_data(RAND_POOL *pool, unsigned char *out)
238 rand_pool_reattach(pool, out);
242 DEFINE_RUN_ONCE_STATIC(do_rand_init)
244 # ifndef OPENSSL_NO_ENGINE
245 rand_engine_lock = CRYPTO_THREAD_lock_new();
246 if (rand_engine_lock == NULL)
250 rand_meth_lock = CRYPTO_THREAD_lock_new();
251 if (rand_meth_lock == NULL)
254 if (!rand_pool_init())
261 CRYPTO_THREAD_lock_free(rand_meth_lock);
262 rand_meth_lock = NULL;
263 # ifndef OPENSSL_NO_ENGINE
264 CRYPTO_THREAD_lock_free(rand_engine_lock);
265 rand_engine_lock = NULL;
270 void rand_cleanup_int(void)
272 const RAND_METHOD *meth = default_RAND_meth;
277 if (meth != NULL && meth->cleanup != NULL)
279 RAND_set_rand_method(NULL);
281 # ifndef OPENSSL_NO_ENGINE
282 CRYPTO_THREAD_lock_free(rand_engine_lock);
283 rand_engine_lock = NULL;
285 CRYPTO_THREAD_lock_free(rand_meth_lock);
286 rand_meth_lock = NULL;
290 /* TODO(3.0): Do we need to handle this somehow in the FIPS module? */
292 * RAND_close_seed_files() ensures that any seed file descriptors are
295 void RAND_keep_random_devices_open(int keep)
297 if (RUN_ONCE(&rand_init, do_rand_init))
298 rand_pool_keep_random_devices_open(keep);
302 * RAND_poll() reseeds the default RNG using random input
304 * The random input is obtained from polling various entropy
305 * sources which depend on the operating system and are
306 * configurable via the --with-rand-seed configure option.
312 const RAND_METHOD *meth = RAND_get_rand_method();
314 if (meth == RAND_OpenSSL()) {
315 /* fill random pool and seed the master DRBG */
316 RAND_DRBG *drbg = RAND_DRBG_get0_master();
321 rand_drbg_lock(drbg);
322 ret = rand_drbg_restart(drbg, NULL, 0, 0);
323 rand_drbg_unlock(drbg);
328 RAND_POOL *pool = NULL;
330 /* fill random pool and seed the current legacy RNG */
331 pool = rand_pool_new(RAND_DRBG_STRENGTH, 1,
332 (RAND_DRBG_STRENGTH + 7) / 8,
333 RAND_POOL_MAX_LENGTH);
337 if (rand_pool_acquire_entropy(pool) == 0)
340 if (meth->add == NULL
341 || meth->add(rand_pool_buffer(pool),
342 rand_pool_length(pool),
343 (rand_pool_entropy(pool) / 8.0)) == 0)
349 rand_pool_free(pool);
354 #endif /* FIPS_MODE */
357 * Allocate memory and initialize a new random pool
360 RAND_POOL *rand_pool_new(int entropy_requested, int secure,
361 size_t min_len, size_t max_len)
363 RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool));
364 size_t min_alloc_size = RAND_POOL_MIN_ALLOCATION(secure);
367 RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE);
371 pool->min_len = min_len;
372 pool->max_len = (max_len > RAND_POOL_MAX_LENGTH) ?
373 RAND_POOL_MAX_LENGTH : max_len;
374 pool->alloc_len = min_len < min_alloc_size ? min_alloc_size : min_len;
375 if (pool->alloc_len > pool->max_len)
376 pool->alloc_len = pool->max_len;
379 pool->buffer = OPENSSL_secure_zalloc(pool->alloc_len);
381 pool->buffer = OPENSSL_zalloc(pool->alloc_len);
383 if (pool->buffer == NULL) {
384 RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE);
388 pool->entropy_requested = entropy_requested;
389 pool->secure = secure;
399 * Attach new random pool to the given buffer
401 * This function is intended to be used only for feeding random data
402 * provided by RAND_add() and RAND_seed() into the <master> DRBG.
404 RAND_POOL *rand_pool_attach(const unsigned char *buffer, size_t len,
407 RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool));
410 RANDerr(RAND_F_RAND_POOL_ATTACH, ERR_R_MALLOC_FAILURE);
415 * The const needs to be cast away, but attached buffers will not be
416 * modified (in contrary to allocated buffers which are zeroed and
419 pool->buffer = (unsigned char *) buffer;
424 pool->min_len = pool->max_len = pool->alloc_len = pool->len;
425 pool->entropy = entropy;
431 * Free |pool|, securely erasing its buffer.
433 void rand_pool_free(RAND_POOL *pool)
439 * Although it would be advisable from a cryptographical viewpoint,
440 * we are not allowed to clear attached buffers, since they are passed
441 * to rand_pool_attach() as `const unsigned char*`.
442 * (see corresponding comment in rand_pool_attach()).
444 if (!pool->attached) {
446 OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len);
448 OPENSSL_clear_free(pool->buffer, pool->alloc_len);
455 * Return the |pool|'s buffer to the caller (readonly).
457 const unsigned char *rand_pool_buffer(RAND_POOL *pool)
463 * Return the |pool|'s entropy to the caller.
465 size_t rand_pool_entropy(RAND_POOL *pool)
467 return pool->entropy;
471 * Return the |pool|'s buffer length to the caller.
473 size_t rand_pool_length(RAND_POOL *pool)
479 * Detach the |pool| buffer and return it to the caller.
480 * It's the responsibility of the caller to free the buffer
481 * using OPENSSL_secure_clear_free() or to re-attach it
482 * again to the pool using rand_pool_reattach().
484 unsigned char *rand_pool_detach(RAND_POOL *pool)
486 unsigned char *ret = pool->buffer;
493 * Re-attach the |pool| buffer. It is only allowed to pass
494 * the |buffer| which was previously detached from the same pool.
496 void rand_pool_reattach(RAND_POOL *pool, unsigned char *buffer)
498 pool->buffer = buffer;
499 OPENSSL_cleanse(pool->buffer, pool->len);
504 * If |entropy_factor| bits contain 1 bit of entropy, how many bytes does one
505 * need to obtain at least |bits| bits of entropy?
507 #define ENTROPY_TO_BYTES(bits, entropy_factor) \
508 (((bits) * (entropy_factor) + 7) / 8)
512 * Checks whether the |pool|'s entropy is available to the caller.
513 * This is the case when entropy count and buffer length are high enough.
516 * |entropy| if the entropy count and buffer size is large enough
519 size_t rand_pool_entropy_available(RAND_POOL *pool)
521 if (pool->entropy < pool->entropy_requested)
524 if (pool->len < pool->min_len)
527 return pool->entropy;
531 * Returns the (remaining) amount of entropy needed to fill
535 size_t rand_pool_entropy_needed(RAND_POOL *pool)
537 if (pool->entropy < pool->entropy_requested)
538 return pool->entropy_requested - pool->entropy;
543 /* Increase the allocation size -- not usable for an attached pool */
544 static int rand_pool_grow(RAND_POOL *pool, size_t len)
546 if (len > pool->alloc_len - pool->len) {
548 const size_t limit = pool->max_len / 2;
549 size_t newlen = pool->alloc_len;
551 if (pool->attached || len > pool->max_len - pool->len) {
552 RANDerr(RAND_F_RAND_POOL_GROW, ERR_R_INTERNAL_ERROR);
557 newlen = newlen < limit ? newlen * 2 : pool->max_len;
558 while (len > newlen - pool->len);
561 p = OPENSSL_secure_zalloc(newlen);
563 p = OPENSSL_zalloc(newlen);
565 RANDerr(RAND_F_RAND_POOL_GROW, ERR_R_MALLOC_FAILURE);
568 memcpy(p, pool->buffer, pool->len);
570 OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len);
572 OPENSSL_clear_free(pool->buffer, pool->alloc_len);
574 pool->alloc_len = newlen;
580 * Returns the number of bytes needed to fill the pool, assuming
581 * the input has 1 / |entropy_factor| entropy bits per data bit.
582 * In case of an error, 0 is returned.
585 size_t rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_factor)
588 size_t entropy_needed = rand_pool_entropy_needed(pool);
590 if (entropy_factor < 1) {
591 RANDerr(RAND_F_RAND_POOL_BYTES_NEEDED, RAND_R_ARGUMENT_OUT_OF_RANGE);
595 bytes_needed = ENTROPY_TO_BYTES(entropy_needed, entropy_factor);
597 if (bytes_needed > pool->max_len - pool->len) {
598 /* not enough space left */
599 RANDerr(RAND_F_RAND_POOL_BYTES_NEEDED, RAND_R_RANDOM_POOL_OVERFLOW);
603 if (pool->len < pool->min_len &&
604 bytes_needed < pool->min_len - pool->len)
605 /* to meet the min_len requirement */
606 bytes_needed = pool->min_len - pool->len;
609 * Make sure the buffer is large enough for the requested amount
610 * of data. This guarantees that existing code patterns where
611 * rand_pool_add_begin, rand_pool_add_end or rand_pool_add
612 * are used to collect entropy data without any error handling
613 * whatsoever, continue to be valid.
614 * Furthermore if the allocation here fails once, make sure that
615 * we don't fall back to a less secure or even blocking random source,
616 * as that could happen by the existing code patterns.
617 * This is not a concern for additional data, therefore that
618 * is not needed if rand_pool_grow fails in other places.
620 if (!rand_pool_grow(pool, bytes_needed)) {
621 /* persistent error for this pool */
622 pool->max_len = pool->len = 0;
629 /* Returns the remaining number of bytes available */
630 size_t rand_pool_bytes_remaining(RAND_POOL *pool)
632 return pool->max_len - pool->len;
636 * Add random bytes to the random pool.
638 * It is expected that the |buffer| contains |len| bytes of
639 * random input which contains at least |entropy| bits of
642 * Returns 1 if the added amount is adequate, otherwise 0
644 int rand_pool_add(RAND_POOL *pool,
645 const unsigned char *buffer, size_t len, size_t entropy)
647 if (len > pool->max_len - pool->len) {
648 RANDerr(RAND_F_RAND_POOL_ADD, RAND_R_ENTROPY_INPUT_TOO_LONG);
652 if (pool->buffer == NULL) {
653 RANDerr(RAND_F_RAND_POOL_ADD, ERR_R_INTERNAL_ERROR);
659 * This is to protect us from accidentally passing the buffer
660 * returned from rand_pool_add_begin.
661 * The check for alloc_len makes sure we do not compare the
662 * address of the end of the allocated memory to something
663 * different, since that comparison would have an
664 * indeterminate result.
666 if (pool->alloc_len > pool->len && pool->buffer + pool->len == buffer) {
667 RANDerr(RAND_F_RAND_POOL_ADD, ERR_R_INTERNAL_ERROR);
671 * We have that only for cases when a pool is used to collect
673 * For entropy data, as long as the allocation request stays within
674 * the limits given by rand_pool_bytes_needed this rand_pool_grow
675 * below is guaranteed to succeed, thus no allocation happens.
677 if (!rand_pool_grow(pool, len))
679 memcpy(pool->buffer + pool->len, buffer, len);
681 pool->entropy += entropy;
688 * Start to add random bytes to the random pool in-place.
690 * Reserves the next |len| bytes for adding random bytes in-place
691 * and returns a pointer to the buffer.
692 * The caller is allowed to copy up to |len| bytes into the buffer.
693 * If |len| == 0 this is considered a no-op and a NULL pointer
694 * is returned without producing an error message.
696 * After updating the buffer, rand_pool_add_end() needs to be called
697 * to finish the udpate operation (see next comment).
699 unsigned char *rand_pool_add_begin(RAND_POOL *pool, size_t len)
704 if (len > pool->max_len - pool->len) {
705 RANDerr(RAND_F_RAND_POOL_ADD_BEGIN, RAND_R_RANDOM_POOL_OVERFLOW);
709 if (pool->buffer == NULL) {
710 RANDerr(RAND_F_RAND_POOL_ADD_BEGIN, ERR_R_INTERNAL_ERROR);
715 * As long as the allocation request stays within the limits given
716 * by rand_pool_bytes_needed this rand_pool_grow below is guaranteed
717 * to succeed, thus no allocation happens.
718 * We have that only for cases when a pool is used to collect
719 * additional data. Then the buffer might need to grow here,
720 * and of course the caller is responsible to check the return
721 * value of this function.
723 if (!rand_pool_grow(pool, len))
726 return pool->buffer + pool->len;
730 * Finish to add random bytes to the random pool in-place.
732 * Finishes an in-place update of the random pool started by
733 * rand_pool_add_begin() (see previous comment).
734 * It is expected that |len| bytes of random input have been added
735 * to the buffer which contain at least |entropy| bits of randomness.
736 * It is allowed to add less bytes than originally reserved.
738 int rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy)
740 if (len > pool->alloc_len - pool->len) {
741 RANDerr(RAND_F_RAND_POOL_ADD_END, RAND_R_RANDOM_POOL_OVERFLOW);
747 pool->entropy += entropy;
754 int RAND_set_rand_method(const RAND_METHOD *meth)
756 if (!RUN_ONCE(&rand_init, do_rand_init))
759 CRYPTO_THREAD_write_lock(rand_meth_lock);
760 # ifndef OPENSSL_NO_ENGINE
761 ENGINE_finish(funct_ref);
764 default_RAND_meth = meth;
765 CRYPTO_THREAD_unlock(rand_meth_lock);
770 const RAND_METHOD *RAND_get_rand_method(void)
775 const RAND_METHOD *tmp_meth = NULL;
777 if (!RUN_ONCE(&rand_init, do_rand_init))
780 CRYPTO_THREAD_write_lock(rand_meth_lock);
781 if (default_RAND_meth == NULL) {
782 # ifndef OPENSSL_NO_ENGINE
785 /* If we have an engine that can do RAND, use it. */
786 if ((e = ENGINE_get_default_RAND()) != NULL
787 && (tmp_meth = ENGINE_get_RAND(e)) != NULL) {
789 default_RAND_meth = tmp_meth;
792 default_RAND_meth = &rand_meth;
795 default_RAND_meth = &rand_meth;
798 tmp_meth = default_RAND_meth;
799 CRYPTO_THREAD_unlock(rand_meth_lock);
804 #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODE)
805 int RAND_set_rand_engine(ENGINE *engine)
807 const RAND_METHOD *tmp_meth = NULL;
809 if (!RUN_ONCE(&rand_init, do_rand_init))
812 if (engine != NULL) {
813 if (!ENGINE_init(engine))
815 tmp_meth = ENGINE_get_RAND(engine);
816 if (tmp_meth == NULL) {
817 ENGINE_finish(engine);
821 CRYPTO_THREAD_write_lock(rand_engine_lock);
822 /* This function releases any prior ENGINE so call it first */
823 RAND_set_rand_method(tmp_meth);
825 CRYPTO_THREAD_unlock(rand_engine_lock);
830 void RAND_seed(const void *buf, int num)
832 const RAND_METHOD *meth = RAND_get_rand_method();
834 if (meth->seed != NULL)
835 meth->seed(buf, num);
838 void RAND_add(const void *buf, int num, double randomness)
840 const RAND_METHOD *meth = RAND_get_rand_method();
842 if (meth->add != NULL)
843 meth->add(buf, num, randomness);
847 * This function is not part of RAND_METHOD, so if we're not using
848 * the default method, then just call RAND_bytes(). Otherwise make
849 * sure we're instantiated and use the private DRBG.
851 int rand_priv_bytes_ex(OPENSSL_CTX *ctx, unsigned char *buf, int num)
855 const RAND_METHOD *meth = RAND_get_rand_method();
857 if (meth != RAND_OpenSSL())
858 return meth->bytes(buf, num);
860 drbg = OPENSSL_CTX_get0_private_drbg(ctx);
864 ret = RAND_DRBG_bytes(drbg, buf, num);
868 int RAND_priv_bytes(unsigned char *buf, int num)
870 return rand_priv_bytes_ex(NULL, buf, num);
873 int rand_bytes_ex(OPENSSL_CTX *ctx, unsigned char *buf, int num)
877 const RAND_METHOD *meth = RAND_get_rand_method();
879 if (meth != RAND_OpenSSL()) {
880 if (meth->bytes != NULL)
881 return meth->bytes(buf, num);
882 RANDerr(RAND_F_RAND_BYTES_EX, RAND_R_FUNC_NOT_IMPLEMENTED);
886 drbg = OPENSSL_CTX_get0_public_drbg(ctx);
890 ret = RAND_DRBG_bytes(drbg, buf, num);
894 int RAND_bytes(unsigned char *buf, int num)
896 return rand_bytes_ex(NULL, buf, num);
899 #if !defined(OPENSSL_NO_DEPRECATED_1_1_0) && !defined(FIPS_MODE)
900 int RAND_pseudo_bytes(unsigned char *buf, int num)
902 const RAND_METHOD *meth = RAND_get_rand_method();
904 if (meth->pseudorand != NULL)
905 return meth->pseudorand(buf, num);
910 int RAND_status(void)
912 const RAND_METHOD *meth = RAND_get_rand_method();
914 if (meth->status != NULL)
915 return meth->status();