X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Frand_lib.c;h=e7dfb07de21466e07f633f84fcd4562eaba8ff09;hp=a5eb0bc7ae318a2f94e32e8cd6ae17c2c574f4fe;hb=f000e82898af251442ca52e81fc1ee45996090dc;hpb=f844f9eb44186df2f8b0cfd3264b4eb003d8c61a diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c index a5eb0bc7ae..e7dfb07de2 100644 --- a/crypto/rand/rand_lib.c +++ b/crypto/rand/rand_lib.c @@ -18,6 +18,9 @@ #include "e_os.h" #ifndef FIPS_MODULE +# include "prov/rand_pool.h" +# include "prov/seeding.h" + # ifndef OPENSSL_NO_ENGINE /* non-NULL if default_RAND_meth is ENGINE-provided */ static ENGINE *funct_ref; @@ -28,217 +31,7 @@ static const RAND_METHOD *default_RAND_meth; static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT; static int rand_inited = 0; -#endif /* FIPS_MODULE */ - -#ifdef OPENSSL_RAND_SEED_RDTSC -/* - * IMPORTANT NOTE: It is not currently possible to use this code - * because we are not sure about the amount of randomness it provides. - * Some SP900 tests have been run, but there is internal skepticism. - * So for now this code is not used. - */ -# error "RDTSC enabled? Should not be possible!" - -/* - * Acquire entropy from high-speed clock - * - * Since we get some randomness from the low-order bits of the - * high-speed clock, it can help. - * - * Returns the total entropy count, if it exceeds the requested - * entropy count. Otherwise, returns an entropy count of 0. - */ -size_t rand_acquire_entropy_from_tsc(RAND_POOL *pool) -{ - unsigned char c; - int i; - - if ((OPENSSL_ia32cap_P[0] & (1 << 4)) != 0) { - for (i = 0; i < TSC_READ_COUNT; i++) { - c = (unsigned char)(OPENSSL_rdtsc() & 0xFF); - rand_pool_add(pool, &c, 1, 4); - } - } - return rand_pool_entropy_available(pool); -} -#endif - -#ifdef OPENSSL_RAND_SEED_RDCPU -size_t OPENSSL_ia32_rdseed_bytes(unsigned char *buf, size_t len); -size_t OPENSSL_ia32_rdrand_bytes(unsigned char *buf, size_t len); - -/* - * Acquire entropy using Intel-specific cpu instructions - * - * Uses the RDSEED instruction if available, otherwise uses - * RDRAND if available. - * - * For the differences between RDSEED and RDRAND, and why RDSEED - * is the preferred choice, see https://goo.gl/oK3KcN - * - * Returns the total entropy count, if it exceeds the requested - * entropy count. Otherwise, returns an entropy count of 0. - */ -size_t rand_acquire_entropy_from_cpu(RAND_POOL *pool) -{ - size_t bytes_needed; - unsigned char *buffer; - - bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/); - if (bytes_needed > 0) { - buffer = rand_pool_add_begin(pool, bytes_needed); - - if (buffer != NULL) { - /* Whichever comes first, use RDSEED, RDRAND or nothing */ - if ((OPENSSL_ia32cap_P[2] & (1 << 18)) != 0) { - if (OPENSSL_ia32_rdseed_bytes(buffer, bytes_needed) - == bytes_needed) { - rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed); - } - } else if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) { - if (OPENSSL_ia32_rdrand_bytes(buffer, bytes_needed) - == bytes_needed) { - rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed); - } - } else { - rand_pool_add_end(pool, 0, 0); - } - } - } - - return rand_pool_entropy_available(pool); -} -#endif - - -/* - * Implements the get_entropy() callback (see RAND_DRBG_set_callbacks()) - * - * If the DRBG has a parent, then the required amount of entropy input - * is fetched using the parent's RAND_DRBG_generate(). - * - * Otherwise, the entropy is polled from the system entropy sources - * using rand_pool_acquire_entropy(). - * - * If a random pool has been added to the DRBG using RAND_add(), then - * its entropy will be used up first. - */ -size_t rand_drbg_get_entropy(RAND_DRBG *drbg, - unsigned char **pout, - int entropy, size_t min_len, size_t max_len, - int prediction_resistance) -{ - size_t ret = 0; - size_t entropy_available = 0; - RAND_POOL *pool; - - if (drbg->parent != NULL && drbg->strength > drbg->parent->strength) { - /* - * We currently don't support the algorithm from NIST SP 800-90C - * 10.1.2 to use a weaker DRBG as source - */ - RANDerr(RAND_F_RAND_DRBG_GET_ENTROPY, RAND_R_PARENT_STRENGTH_TOO_WEAK); - return 0; - } - - if (drbg->seed_pool != NULL) { - pool = drbg->seed_pool; - pool->entropy_requested = entropy; - } else { - pool = rand_pool_new(entropy, drbg->secure, min_len, max_len); - if (pool == NULL) - return 0; - } - - if (drbg->parent != NULL) { - size_t bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/); - unsigned char *buffer = rand_pool_add_begin(pool, bytes_needed); - - if (buffer != NULL) { - size_t bytes = 0; - - /* - * Get random data from parent. Include our address as additional input, - * in order to provide some additional distinction between different - * DRBG child instances. - * Our lock is already held, but we need to lock our parent before - * generating bits from it. (Note: taking the lock will be a no-op - * if locking if drbg->parent->lock == NULL.) - */ - rand_drbg_lock(drbg->parent); - if (RAND_DRBG_generate(drbg->parent, - buffer, bytes_needed, - prediction_resistance, - (unsigned char *)&drbg, sizeof(drbg)) != 0) - bytes = bytes_needed; - drbg->reseed_next_counter - = tsan_load(&drbg->parent->reseed_prop_counter); - rand_drbg_unlock(drbg->parent); - - rand_pool_add_end(pool, bytes, 8 * bytes); - entropy_available = rand_pool_entropy_available(pool); - } - - } else { - /* Get entropy by polling system entropy sources. */ - entropy_available = rand_pool_acquire_entropy(pool); - } - - if (entropy_available > 0) { - ret = rand_pool_length(pool); - *pout = rand_pool_detach(pool); - } - - if (drbg->seed_pool == NULL) - rand_pool_free(pool); - return ret; -} - -/* - * Implements the cleanup_entropy() callback (see RAND_DRBG_set_callbacks()) - * - */ -void rand_drbg_cleanup_entropy(RAND_DRBG *drbg, - unsigned char *out, size_t outlen) -{ - if (drbg->seed_pool == NULL) { - if (drbg->secure) - OPENSSL_secure_clear_free(out, outlen); - else - OPENSSL_clear_free(out, outlen); - } -} - -/* - * Generate additional data that can be used for the drbg. The data does - * not need to contain entropy, but it's useful if it contains at least - * some bits that are unpredictable. - * - * Returns 0 on failure. - * - * On success it allocates a buffer at |*pout| and returns the length of - * the data. The buffer should get freed using OPENSSL_secure_clear_free(). - */ -size_t rand_drbg_get_additional_data(RAND_POOL *pool, unsigned char **pout) -{ - size_t ret = 0; - - if (rand_pool_add_additional_data(pool) == 0) - goto err; - - ret = rand_pool_length(pool); - *pout = rand_pool_detach(pool); - - err: - return ret; -} - -void rand_drbg_cleanup_additional_data(RAND_POOL *pool, unsigned char *out) -{ - rand_pool_reattach(pool, out); -} -#ifndef FIPS_MODULE DEFINE_RUN_ONCE_STATIC(do_rand_init) { # ifndef OPENSSL_NO_ENGINE @@ -287,10 +80,10 @@ void rand_cleanup_int(void) rand_inited = 0; } -/* TODO(3.0): Do we need to handle this somehow in the FIPS module? */ /* * RAND_close_seed_files() ensures that any seed file descriptors are - * closed after use. + * closed after use. This only applies to libcrypto/default provider, + * it does not apply to other providers. */ void RAND_keep_random_devices_open(int keep) { @@ -307,29 +100,14 @@ void RAND_keep_random_devices_open(int keep) */ int RAND_poll(void) { - int ret = 0; - const RAND_METHOD *meth = RAND_get_rand_method(); + int ret = meth == RAND_OpenSSL(); + RAND_POOL *pool; if (meth == NULL) return 0; - if (meth == RAND_OpenSSL()) { - /* fill random pool and seed the master DRBG */ - RAND_DRBG *drbg = RAND_DRBG_get0_master(); - - if (drbg == NULL) - return 0; - - rand_drbg_lock(drbg); - ret = rand_drbg_restart(drbg, NULL, 0, 0); - rand_drbg_unlock(drbg); - - return ret; - - } else { - RAND_POOL *pool = NULL; - + if (!ret) { /* fill random pool and seed the current legacy RNG */ pool = rand_pool_new(RAND_DRBG_STRENGTH, 1, (RAND_DRBG_STRENGTH + 7) / 8, @@ -337,7 +115,7 @@ int RAND_poll(void) if (pool == NULL) return 0; - if (rand_pool_acquire_entropy(pool) == 0) + if (prov_pool_acquire_entropy(pool) == 0) goto err; if (meth->add == NULL @@ -347,413 +125,12 @@ int RAND_poll(void) goto err; ret = 1; - err: rand_pool_free(pool); } - - return ret; -} -#endif /* FIPS_MODULE */ - -/* - * Allocate memory and initialize a new random pool - */ - -RAND_POOL *rand_pool_new(int entropy_requested, int secure, - size_t min_len, size_t max_len) -{ - RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool)); - size_t min_alloc_size = RAND_POOL_MIN_ALLOCATION(secure); - - if (pool == NULL) { - RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE); - return NULL; - } - - pool->min_len = min_len; - pool->max_len = (max_len > RAND_POOL_MAX_LENGTH) ? - RAND_POOL_MAX_LENGTH : max_len; - pool->alloc_len = min_len < min_alloc_size ? min_alloc_size : min_len; - if (pool->alloc_len > pool->max_len) - pool->alloc_len = pool->max_len; - - if (secure) - pool->buffer = OPENSSL_secure_zalloc(pool->alloc_len); - else - pool->buffer = OPENSSL_zalloc(pool->alloc_len); - - if (pool->buffer == NULL) { - RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE); - goto err; - } - - pool->entropy_requested = entropy_requested; - pool->secure = secure; - - return pool; - -err: - OPENSSL_free(pool); - return NULL; -} - -/* - * Attach new random pool to the given buffer - * - * This function is intended to be used only for feeding random data - * provided by RAND_add() and RAND_seed() into the DRBG. - */ -RAND_POOL *rand_pool_attach(const unsigned char *buffer, size_t len, - size_t entropy) -{ - RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool)); - - if (pool == NULL) { - RANDerr(RAND_F_RAND_POOL_ATTACH, ERR_R_MALLOC_FAILURE); - return NULL; - } - - /* - * The const needs to be cast away, but attached buffers will not be - * modified (in contrary to allocated buffers which are zeroed and - * freed in the end). - */ - pool->buffer = (unsigned char *) buffer; - pool->len = len; - - pool->attached = 1; - - pool->min_len = pool->max_len = pool->alloc_len = pool->len; - pool->entropy = entropy; - - return pool; -} - -/* - * Free |pool|, securely erasing its buffer. - */ -void rand_pool_free(RAND_POOL *pool) -{ - if (pool == NULL) - return; - - /* - * Although it would be advisable from a cryptographical viewpoint, - * we are not allowed to clear attached buffers, since they are passed - * to rand_pool_attach() as `const unsigned char*`. - * (see corresponding comment in rand_pool_attach()). - */ - if (!pool->attached) { - if (pool->secure) - OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len); - else - OPENSSL_clear_free(pool->buffer, pool->alloc_len); - } - - OPENSSL_free(pool); -} - -/* - * Return the |pool|'s buffer to the caller (readonly). - */ -const unsigned char *rand_pool_buffer(RAND_POOL *pool) -{ - return pool->buffer; -} - -/* - * Return the |pool|'s entropy to the caller. - */ -size_t rand_pool_entropy(RAND_POOL *pool) -{ - return pool->entropy; -} - -/* - * Return the |pool|'s buffer length to the caller. - */ -size_t rand_pool_length(RAND_POOL *pool) -{ - return pool->len; -} - -/* - * Detach the |pool| buffer and return it to the caller. - * It's the responsibility of the caller to free the buffer - * using OPENSSL_secure_clear_free() or to re-attach it - * again to the pool using rand_pool_reattach(). - */ -unsigned char *rand_pool_detach(RAND_POOL *pool) -{ - unsigned char *ret = pool->buffer; - pool->buffer = NULL; - pool->entropy = 0; return ret; } -/* - * Re-attach the |pool| buffer. It is only allowed to pass - * the |buffer| which was previously detached from the same pool. - */ -void rand_pool_reattach(RAND_POOL *pool, unsigned char *buffer) -{ - pool->buffer = buffer; - OPENSSL_cleanse(pool->buffer, pool->len); - pool->len = 0; -} - -/* - * If |entropy_factor| bits contain 1 bit of entropy, how many bytes does one - * need to obtain at least |bits| bits of entropy? - */ -#define ENTROPY_TO_BYTES(bits, entropy_factor) \ - (((bits) * (entropy_factor) + 7) / 8) - - -/* - * Checks whether the |pool|'s entropy is available to the caller. - * This is the case when entropy count and buffer length are high enough. - * Returns - * - * |entropy| if the entropy count and buffer size is large enough - * 0 otherwise - */ -size_t rand_pool_entropy_available(RAND_POOL *pool) -{ - if (pool->entropy < pool->entropy_requested) - return 0; - - if (pool->len < pool->min_len) - return 0; - - return pool->entropy; -} - -/* - * Returns the (remaining) amount of entropy needed to fill - * the random pool. - */ - -size_t rand_pool_entropy_needed(RAND_POOL *pool) -{ - if (pool->entropy < pool->entropy_requested) - return pool->entropy_requested - pool->entropy; - - return 0; -} - -/* Increase the allocation size -- not usable for an attached pool */ -static int rand_pool_grow(RAND_POOL *pool, size_t len) -{ - if (len > pool->alloc_len - pool->len) { - unsigned char *p; - const size_t limit = pool->max_len / 2; - size_t newlen = pool->alloc_len; - - if (pool->attached || len > pool->max_len - pool->len) { - RANDerr(RAND_F_RAND_POOL_GROW, ERR_R_INTERNAL_ERROR); - return 0; - } - - do - newlen = newlen < limit ? newlen * 2 : pool->max_len; - while (len > newlen - pool->len); - - if (pool->secure) - p = OPENSSL_secure_zalloc(newlen); - else - p = OPENSSL_zalloc(newlen); - if (p == NULL) { - RANDerr(RAND_F_RAND_POOL_GROW, ERR_R_MALLOC_FAILURE); - return 0; - } - memcpy(p, pool->buffer, pool->len); - if (pool->secure) - OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len); - else - OPENSSL_clear_free(pool->buffer, pool->alloc_len); - pool->buffer = p; - pool->alloc_len = newlen; - } - return 1; -} - -/* - * Returns the number of bytes needed to fill the pool, assuming - * the input has 1 / |entropy_factor| entropy bits per data bit. - * In case of an error, 0 is returned. - */ - -size_t rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_factor) -{ - size_t bytes_needed; - size_t entropy_needed = rand_pool_entropy_needed(pool); - - if (entropy_factor < 1) { - RANDerr(RAND_F_RAND_POOL_BYTES_NEEDED, RAND_R_ARGUMENT_OUT_OF_RANGE); - return 0; - } - - bytes_needed = ENTROPY_TO_BYTES(entropy_needed, entropy_factor); - - if (bytes_needed > pool->max_len - pool->len) { - /* not enough space left */ - RANDerr(RAND_F_RAND_POOL_BYTES_NEEDED, RAND_R_RANDOM_POOL_OVERFLOW); - return 0; - } - - if (pool->len < pool->min_len && - bytes_needed < pool->min_len - pool->len) - /* to meet the min_len requirement */ - bytes_needed = pool->min_len - pool->len; - - /* - * Make sure the buffer is large enough for the requested amount - * of data. This guarantees that existing code patterns where - * rand_pool_add_begin, rand_pool_add_end or rand_pool_add - * are used to collect entropy data without any error handling - * whatsoever, continue to be valid. - * Furthermore if the allocation here fails once, make sure that - * we don't fall back to a less secure or even blocking random source, - * as that could happen by the existing code patterns. - * This is not a concern for additional data, therefore that - * is not needed if rand_pool_grow fails in other places. - */ - if (!rand_pool_grow(pool, bytes_needed)) { - /* persistent error for this pool */ - pool->max_len = pool->len = 0; - return 0; - } - - return bytes_needed; -} - -/* Returns the remaining number of bytes available */ -size_t rand_pool_bytes_remaining(RAND_POOL *pool) -{ - return pool->max_len - pool->len; -} - -/* - * Add random bytes to the random pool. - * - * It is expected that the |buffer| contains |len| bytes of - * random input which contains at least |entropy| bits of - * randomness. - * - * Returns 1 if the added amount is adequate, otherwise 0 - */ -int rand_pool_add(RAND_POOL *pool, - const unsigned char *buffer, size_t len, size_t entropy) -{ - if (len > pool->max_len - pool->len) { - RANDerr(RAND_F_RAND_POOL_ADD, RAND_R_ENTROPY_INPUT_TOO_LONG); - return 0; - } - - if (pool->buffer == NULL) { - RANDerr(RAND_F_RAND_POOL_ADD, ERR_R_INTERNAL_ERROR); - return 0; - } - - if (len > 0) { - /* - * This is to protect us from accidentally passing the buffer - * returned from rand_pool_add_begin. - * The check for alloc_len makes sure we do not compare the - * address of the end of the allocated memory to something - * different, since that comparison would have an - * indeterminate result. - */ - if (pool->alloc_len > pool->len && pool->buffer + pool->len == buffer) { - RANDerr(RAND_F_RAND_POOL_ADD, ERR_R_INTERNAL_ERROR); - return 0; - } - /* - * We have that only for cases when a pool is used to collect - * additional data. - * For entropy data, as long as the allocation request stays within - * the limits given by rand_pool_bytes_needed this rand_pool_grow - * below is guaranteed to succeed, thus no allocation happens. - */ - if (!rand_pool_grow(pool, len)) - return 0; - memcpy(pool->buffer + pool->len, buffer, len); - pool->len += len; - pool->entropy += entropy; - } - - return 1; -} - -/* - * Start to add random bytes to the random pool in-place. - * - * Reserves the next |len| bytes for adding random bytes in-place - * and returns a pointer to the buffer. - * The caller is allowed to copy up to |len| bytes into the buffer. - * If |len| == 0 this is considered a no-op and a NULL pointer - * is returned without producing an error message. - * - * After updating the buffer, rand_pool_add_end() needs to be called - * to finish the update operation (see next comment). - */ -unsigned char *rand_pool_add_begin(RAND_POOL *pool, size_t len) -{ - if (len == 0) - return NULL; - - if (len > pool->max_len - pool->len) { - RANDerr(RAND_F_RAND_POOL_ADD_BEGIN, RAND_R_RANDOM_POOL_OVERFLOW); - return NULL; - } - - if (pool->buffer == NULL) { - RANDerr(RAND_F_RAND_POOL_ADD_BEGIN, ERR_R_INTERNAL_ERROR); - return NULL; - } - - /* - * As long as the allocation request stays within the limits given - * by rand_pool_bytes_needed this rand_pool_grow below is guaranteed - * to succeed, thus no allocation happens. - * We have that only for cases when a pool is used to collect - * additional data. Then the buffer might need to grow here, - * and of course the caller is responsible to check the return - * value of this function. - */ - if (!rand_pool_grow(pool, len)) - return NULL; - - return pool->buffer + pool->len; -} - -/* - * Finish to add random bytes to the random pool in-place. - * - * Finishes an in-place update of the random pool started by - * rand_pool_add_begin() (see previous comment). - * It is expected that |len| bytes of random input have been added - * to the buffer which contain at least |entropy| bits of randomness. - * It is allowed to add less bytes than originally reserved. - */ -int rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy) -{ - if (len > pool->alloc_len - pool->len) { - RANDerr(RAND_F_RAND_POOL_ADD_END, RAND_R_RANDOM_POOL_OVERFLOW); - return 0; - } - - if (len > 0) { - pool->len += len; - pool->entropy += entropy; - } - - return 1; -} - -#ifndef FIPS_MODULE int RAND_set_rand_method(const RAND_METHOD *meth) { if (!RUN_ONCE(&rand_init, do_rand_init)) @@ -768,13 +145,9 @@ int RAND_set_rand_method(const RAND_METHOD *meth) CRYPTO_THREAD_unlock(rand_meth_lock); return 1; } -#endif const RAND_METHOD *RAND_get_rand_method(void) { -#ifdef FIPS_MODULE - return NULL; -#else const RAND_METHOD *tmp_meth = NULL; if (!RUN_ONCE(&rand_init, do_rand_init)) @@ -801,10 +174,9 @@ const RAND_METHOD *RAND_get_rand_method(void) tmp_meth = default_RAND_meth; CRYPTO_THREAD_unlock(rand_meth_lock); return tmp_meth; -#endif } -#if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODULE) +# if !defined(OPENSSL_NO_ENGINE) int RAND_set_rand_engine(ENGINE *engine) { const RAND_METHOD *tmp_meth = NULL; @@ -828,7 +200,7 @@ int RAND_set_rand_engine(ENGINE *engine) CRYPTO_THREAD_unlock(rand_engine_lock); return 1; } -#endif +# endif void RAND_seed(const void *buf, int num) { @@ -846,6 +218,38 @@ void RAND_add(const void *buf, int num, double randomness) meth->add(buf, num, randomness); } +# if !defined(OPENSSL_NO_DEPRECATED_1_1_0) +int RAND_pseudo_bytes(unsigned char *buf, int num) +{ + const RAND_METHOD *meth = RAND_get_rand_method(); + + if (meth != NULL && meth->pseudorand != NULL) + return meth->pseudorand(buf, num); + RANDerr(RAND_F_RAND_PSEUDO_BYTES, RAND_R_FUNC_NOT_IMPLEMENTED); + return -1; +} +# endif + +int RAND_status(void) +{ + RAND_DRBG *drbg; + const RAND_METHOD *meth = RAND_get_rand_method(); + + if (meth != NULL && meth != RAND_OpenSSL()) + return meth->status != NULL ? meth->status() : 0; + + if ((drbg = RAND_DRBG_get0_master()) == NULL || drbg->rand == NULL) + return EVP_RAND_STATE_UNINITIALISED; + return EVP_RAND_state(drbg->rand) == EVP_RAND_STATE_READY; +} +#else /* !FIPS_MODULE */ + +const RAND_METHOD *RAND_get_rand_method(void) +{ + return NULL; +} +#endif /* !FIPS_MODULE */ + /* * This function is not part of RAND_METHOD, so if we're not using * the default method, then just call RAND_bytes(). Otherwise make @@ -898,24 +302,3 @@ int RAND_bytes(unsigned char *buf, int num) { return RAND_bytes_ex(NULL, buf, num); } - -#if !defined(OPENSSL_NO_DEPRECATED_1_1_0) && !defined(FIPS_MODULE) -int RAND_pseudo_bytes(unsigned char *buf, int num) -{ - const RAND_METHOD *meth = RAND_get_rand_method(); - - if (meth != NULL && meth->pseudorand != NULL) - return meth->pseudorand(buf, num); - RANDerr(RAND_F_RAND_PSEUDO_BYTES, RAND_R_FUNC_NOT_IMPLEMENTED); - return -1; -} -#endif - -int RAND_status(void) -{ - const RAND_METHOD *meth = RAND_get_rand_method(); - - if (meth != NULL && meth->status != NULL) - return meth->status(); - return 0; -}