/*
* Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <time.h>
#include "internal/cryptlib.h"
#include <openssl/opensslconf.h>
#include "crypto/rand.h"
#include <openssl/engine.h>
#include "internal/thread_once.h"
#include "rand_local.h"
#include "e_os.h"
#ifdef OPENSSL_FIPS
# include <openssl/fips.h>
# include <openssl/fips_rand.h>
#endif
#ifndef OPENSSL_NO_ENGINE
/* non-NULL if default_RAND_meth is ENGINE-provided */
static ENGINE *funct_ref;
static CRYPTO_RWLOCK *rand_engine_lock;
#endif
static CRYPTO_RWLOCK *rand_meth_lock;
static const RAND_METHOD *default_RAND_meth;
static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT;
static CRYPTO_RWLOCK *rand_nonce_lock;
static int rand_nonce_count;
static int rand_inited = 0;
#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);
extern unsigned int OPENSSL_ia32cap_P[];
/*
* 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 {
if (prediction_resistance) {
/*
* We don't have any entropy sources that comply with the NIST
* standard to provide prediction resistance (see NIST SP 800-90C,
* Section 5.4).
*/
RANDerr(RAND_F_RAND_DRBG_GET_ENTROPY,
RAND_R_PREDICTION_RESISTANCE_NOT_SUPPORTED);
goto err;
}
/* 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);
}
err:
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);
}
}
/*
* Implements the get_nonce() callback (see RAND_DRBG_set_callbacks())
*
*/
size_t rand_drbg_get_nonce(RAND_DRBG *drbg,
unsigned char **pout,
int entropy, size_t min_len, size_t max_len)
{
size_t ret = 0;
RAND_POOL *pool;
struct {
void * instance;
int count;
} data;
memset(&data, 0, sizeof(data));
pool = rand_pool_new(0, 0, min_len, max_len);
if (pool == NULL)
return 0;
if (rand_pool_add_nonce_data(pool) == 0)
goto err;
data.instance = drbg;
CRYPTO_atomic_add(&rand_nonce_count, 1, &data.count, rand_nonce_lock);
if (rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0) == 0)
goto err;
ret = rand_pool_length(pool);
*pout = rand_pool_detach(pool);
err:
rand_pool_free(pool);
return ret;
}
/*
* Implements the cleanup_nonce() callback (see RAND_DRBG_set_callbacks())
*
*/
void rand_drbg_cleanup_nonce(RAND_DRBG *drbg,
unsigned char *out, size_t outlen)
{
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);
}
DEFINE_RUN_ONCE_STATIC(do_rand_init)
{
#ifndef OPENSSL_NO_ENGINE
rand_engine_lock = CRYPTO_THREAD_lock_new();
if (rand_engine_lock == NULL)
return 0;
#endif
rand_meth_lock = CRYPTO_THREAD_lock_new();
if (rand_meth_lock == NULL)
goto err1;
rand_nonce_lock = CRYPTO_THREAD_lock_new();
if (rand_nonce_lock == NULL)
goto err2;
if (!rand_pool_init())
goto err3;
rand_inited = 1;
return 1;
err3:
CRYPTO_THREAD_lock_free(rand_nonce_lock);
rand_nonce_lock = NULL;
err2:
CRYPTO_THREAD_lock_free(rand_meth_lock);
rand_meth_lock = NULL;
err1:
#ifndef OPENSSL_NO_ENGINE
CRYPTO_THREAD_lock_free(rand_engine_lock);
rand_engine_lock = NULL;
#endif
return 0;
}
void rand_cleanup_int(void)
{
const RAND_METHOD *meth = default_RAND_meth;
if (!rand_inited)
return;
if (meth != NULL && meth->cleanup != NULL)
meth->cleanup();
RAND_set_rand_method(NULL);
rand_pool_cleanup();
#ifndef OPENSSL_NO_ENGINE
CRYPTO_THREAD_lock_free(rand_engine_lock);
rand_engine_lock = NULL;
#endif
CRYPTO_THREAD_lock_free(rand_meth_lock);
rand_meth_lock = NULL;
CRYPTO_THREAD_lock_free(rand_nonce_lock);
rand_nonce_lock = NULL;
rand_inited = 0;
}
/*
* RAND_close_seed_files() ensures that any seed file descriptors are
* closed after use.
*/
void RAND_keep_random_devices_open(int keep)
{
if (RUN_ONCE(&rand_init, do_rand_init))
rand_pool_keep_random_devices_open(keep);
}
/*
* RAND_poll() reseeds the default RNG using random input
*
* The random input is obtained from polling various entropy
* sources which depend on the operating system and are
* configurable via the --with-rand-seed configure option.
*/
int RAND_poll(void)
{
int ret = 0;
RAND_POOL *pool = NULL;
const RAND_METHOD *meth = RAND_get_rand_method();
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 {
/* fill random pool and seed the current legacy RNG */
pool = rand_pool_new(RAND_DRBG_STRENGTH, 1,
(RAND_DRBG_STRENGTH + 7) / 8,
RAND_POOL_MAX_LENGTH);
if (pool == NULL)
return 0;
if (rand_pool_acquire_entropy(pool) == 0)
goto err;
if (meth->add == NULL
|| meth->add(rand_pool_buffer(pool),
rand_pool_length(pool),
(rand_pool_entropy(pool) / 8.0)) == 0)
goto err;
ret = 1;
}
err:
rand_pool_free(pool);
return ret;
}
/*
* 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 <master> 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;
}
int RAND_set_rand_method(const RAND_METHOD *meth)
{
if (!RUN_ONCE(&rand_init, do_rand_init))
return 0;
CRYPTO_THREAD_write_lock(rand_meth_lock);
#ifndef OPENSSL_NO_ENGINE
ENGINE_finish(funct_ref);
funct_ref = NULL;
#endif
default_RAND_meth = meth;
CRYPTO_THREAD_unlock(rand_meth_lock);
return 1;
}
const RAND_METHOD *RAND_get_rand_method(void)
{
const RAND_METHOD *tmp_meth = NULL;
if (!RUN_ONCE(&rand_init, do_rand_init))
return NULL;
CRYPTO_THREAD_write_lock(rand_meth_lock);
if (default_RAND_meth == NULL) {
#ifndef OPENSSL_NO_ENGINE
ENGINE *e;
/* If we have an engine that can do RAND, use it. */
if ((e = ENGINE_get_default_RAND()) != NULL
&& (tmp_meth = ENGINE_get_RAND(e)) != NULL) {
funct_ref = e;
default_RAND_meth = tmp_meth;
} else {
ENGINE_finish(e);
default_RAND_meth = &rand_meth;
}
#else
default_RAND_meth = &rand_meth;
#endif
}
tmp_meth = default_RAND_meth;
CRYPTO_THREAD_unlock(rand_meth_lock);
return tmp_meth;
}
#ifndef OPENSSL_NO_ENGINE
int RAND_set_rand_engine(ENGINE *engine)
{
const RAND_METHOD *tmp_meth = NULL;
if (!RUN_ONCE(&rand_init, do_rand_init))
return 0;
if (engine != NULL) {
if (!ENGINE_init(engine))
return 0;
tmp_meth = ENGINE_get_RAND(engine);
if (tmp_meth == NULL) {
ENGINE_finish(engine);
return 0;
}
}
CRYPTO_THREAD_write_lock(rand_engine_lock);
/* This function releases any prior ENGINE so call it first */
RAND_set_rand_method(tmp_meth);
funct_ref = engine;
CRYPTO_THREAD_unlock(rand_engine_lock);
return 1;
}
#endif
void RAND_seed(const void *buf, int num)
{
const RAND_METHOD *meth = RAND_get_rand_method();
if (meth != NULL && meth->seed != NULL)
meth->seed(buf, num);
}
void RAND_add(const void *buf, int num, double randomness)
{
const RAND_METHOD *meth = RAND_get_rand_method();
if (meth != NULL && meth->add != NULL)
meth->add(buf, num, randomness);
}
/*
* This function is not part of RAND_METHOD, so if we're not using
* the default method, then just call RAND_bytes(). Otherwise make
* sure we're instantiated and use the private DRBG.
*/
int RAND_priv_bytes(unsigned char *buf, int num)
{
const RAND_METHOD *meth = RAND_get_rand_method();
RAND_DRBG *drbg;
if (meth != NULL && meth != RAND_OpenSSL())
return RAND_bytes(buf, num);
drbg = RAND_DRBG_get0_private();
if (drbg != NULL)
return RAND_DRBG_bytes(drbg, buf, num);
return 0;
}
int RAND_bytes(unsigned char *buf, int num)
{
const RAND_METHOD *meth = RAND_get_rand_method();
if (meth != NULL && meth->bytes != NULL)
return meth->bytes(buf, num);
RANDerr(RAND_F_RAND_BYTES, RAND_R_FUNC_NOT_IMPLEMENTED);
return -1;
}
#if OPENSSL_API_COMPAT < 0x10100000L
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;
}
#ifdef OPENSSL_FIPS
void RAND_set_fips_drbg_type(int type, int flags)
{ /* just a stub for ABI compatibility */
}
int RAND_init_fips(void)
{
/* just a stub for ABI compatibility */
return 1;
}
#endif