/* crypto/rand/md_rand.c */

 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

  * All rights reserved.

  *

  * This package is an SSL implementation written

  * by Eric Young (eay@cryptsoft.com).

  * The implementation was written so as to conform with Netscapes SSL.

  * 

  * This library is free for commercial and non-commercial use as long as

  * the following conditions are aheared to.  The following conditions

  * apply to all code found in this distribution, be it the RC4, RSA,

  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

  * included with this distribution is covered by the same copyright terms

  * except that the holder is Tim Hudson (tjh@cryptsoft.com).

  * 

  * Copyright remains Eric Young's, and as such any Copyright notices in

  * the code are not to be removed.

  * If this package is used in a product, Eric Young should be given attribution

  * as the author of the parts of the library used.

  * This can be in the form of a textual message at program startup or

  * in documentation (online or textual) provided with the package.

  * 

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions

  * are met:

  * 1. Redistributions of source code must retain the copyright

  *    notice, this list of conditions and the following disclaimer.

  * 2. Redistributions in binary form must reproduce the above copyright

  *    notice, this list of conditions and the following disclaimer in the

  *    documentation and/or other materials provided with the distribution.

  * 3. All advertising materials mentioning features or use of this software

  *    must display the following acknowledgement:

  *    "This product includes cryptographic software written by

  *     Eric Young (eay@cryptsoft.com)"

  *    The word 'cryptographic' can be left out if the rouines from the library

  *    being used are not cryptographic related :-).

  * 4. If you include any Windows specific code (or a derivative thereof) from 

  *    the apps directory (application code) you must include an acknowledgement:

  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

  * 

  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND

  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

  * SUCH DAMAGE.

  * 

  * The licence and distribution terms for any publically available version or

  * derivative of this code cannot be changed.  i.e. this code cannot simply be

  * copied and put under another distribution licence

  * [including the GNU Public Licence.]

  */

 /* ====================================================================

  * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions

  * are met:

  *

  * 1. Redistributions of source code must retain the above copyright

  *    notice, this list of conditions and the following disclaimer. 

  *

  * 2. Redistributions in binary form must reproduce the above copyright

  *    notice, this list of conditions and the following disclaimer in

  *    the documentation and/or other materials provided with the

  *    distribution.

  *

  * 3. All advertising materials mentioning features or use of this

  *    software must display the following acknowledgment:

  *    "This product includes software developed by the OpenSSL Project

  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"

  *

  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

  *    endorse or promote products derived from this software without

  *    prior written permission. For written permission, please contact

  *    openssl-core@openssl.org.

  *

  * 5. Products derived from this software may not be called "OpenSSL"

  *    nor may "OpenSSL" appear in their names without prior written

  *    permission of the OpenSSL Project.

  *

  * 6. Redistributions of any form whatsoever must retain the following

  *    acknowledgment:

  *    "This product includes software developed by the OpenSSL Project

  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"

  *

  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

  * OF THE POSSIBILITY OF SUCH DAMAGE.

  * ====================================================================

  *

  * This product includes cryptographic software written by Eric Young

  * (eay@cryptsoft.com).  This product includes software written by Tim

  * Hudson (tjh@cryptsoft.com).

  *

  */

  /*

  © Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

  */

 #ifdef MD_RAND_DEBUG

 # ifndef NDEBUG

 #   define NDEBUG

 # endif

 #endif

 #include <assert.h>

 #include <stdio.h>

 #include <string.h>

 #include "e_os.h"

 #include <openssl/rand.h>

 #include "rand_lcl.h"

 #include <openssl/crypto.h>

 #include <openssl/err.h>

 #if (defined(SYMBIAN) && (defined(__WINSCW__) || defined(__WINS__)))

 #include "libcrypto_wsd_macros.h"

 #include "libcrypto_wsd.h"

 #endif

 #ifdef BN_DEBUG

 # define PREDICT

 #endif

 /* #define PREDICT	1 */

 #define STATE_SIZE	1023

 #ifndef EMULATOR

 static int state_num=0,state_index=0;

 static unsigned char state[STATE_SIZE+MD_DIGEST_LENGTH];

 static unsigned char md[MD_DIGEST_LENGTH];

 static long md_count[2]={0,0};

 static double entropy=0;

 static int initialized=0;

 static unsigned int crypto_lock_rand = 0; /* may be set only when a thread

                                            * holds CRYPTO_LOCK_RAND

                                            * (to prevent double locking) */

 /* access to lockin_thread is synchronized by CRYPTO_LOCK_RAND2 */

 static unsigned long locking_thread = 0; /* valid iff crypto_lock_rand is set */

 #else

 GET_STATIC_VAR_FROM_TLS(state_num,md_rand,int)

 #define state_num (*GET_WSD_VAR_NAME(state_num,md_rand, s)())

 GET_STATIC_VAR_FROM_TLS(state_index,md_rand,int)

 #define state_index (*GET_WSD_VAR_NAME(state_index,md_rand, s)())

 GET_STATIC_ARRAY_FROM_TLS(state,md_rand,unsigned char)

 #define state (GET_WSD_VAR_NAME(state,md_rand, s)())

 GET_STATIC_ARRAY_FROM_TLS(md,md_rand,unsigned char)

 #define md (GET_WSD_VAR_NAME(md,md_rand, s)())

 GET_STATIC_ARRAY_FROM_TLS(md_count,md_rand,unsigned char)

 #define md_count (GET_WSD_VAR_NAME(md_count,md_rand, s)())

 GET_STATIC_VAR_FROM_TLS(entropy,md_rand,double)

 #define entropy (*GET_WSD_VAR_NAME(entropy,md_rand, s)())

 GET_STATIC_VAR_FROM_TLS(initialized,md_rand,int)

 #define initialized (*GET_WSD_VAR_NAME(initialized,md_rand, s)())

 GET_STATIC_VAR_FROM_TLS(crypto_lock_rand,md_rand,unsigned int)

 #define crypto_lock_rand (*GET_WSD_VAR_NAME(crypto_lock_rand,md_rand, s)())

 GET_STATIC_VAR_FROM_TLS(locking_thread,md_rand,unsigned long)

 #define locking_thread  (*GET_WSD_VAR_NAME(locking_thread,md_rand, s)())

 #endif

 #ifdef PREDICT

 int rand_predictable=0;

 #endif

 const char RAND_version[]="RAND" OPENSSL_VERSION_PTEXT;

 static void ssleay_rand_cleanup(void);

 static void ssleay_rand_seed(const void *buf, int num);

 static void ssleay_rand_add(const void *buf, int num, double add_entropy);

 static int ssleay_rand_bytes(unsigned char *buf, int num);

 static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num);

 static int ssleay_rand_status(void);

 #ifndef EMULATOR

 RAND_METHOD rand_ssleay_meth={

 	ssleay_rand_seed,

 	ssleay_rand_bytes,

 	ssleay_rand_cleanup,

 	ssleay_rand_add,

 	ssleay_rand_pseudo_bytes,

 	ssleay_rand_status

 	}; 

 #else

 GET_GLOBAL_VAR_FROM_TLS(rand_ssleay_meth,md_rand, RAND_METHOD)

 #define rand_ssleay_meth (*GET_WSD_VAR_NAME(rand_ssleay_meth,md_rand, g)())

 const RAND_METHOD temp_g_rand_ssleay_meth={

 	ssleay_rand_seed,

 	ssleay_rand_bytes,

 	ssleay_rand_cleanup,

 	ssleay_rand_add,

 	ssleay_rand_pseudo_bytes,

 	ssleay_rand_status

 	}; 

 #endif

 EXPORT_C RAND_METHOD *RAND_SSLeay(void)

 	{

 	return(&rand_ssleay_meth);

 	}

 static void ssleay_rand_cleanup(void)

 	{

 	OPENSSL_cleanse(state,sizeof(state));

 	state_num=0;

 	state_index=0;

 	OPENSSL_cleanse(md,MD_DIGEST_LENGTH);

 	md_count[0]=0;

 	md_count[1]=0;

 	entropy=0;

 	initialized=0;

 	}

 static void ssleay_rand_add(const void *buf, int num, double add)

 	{

 	int i,j,k,st_idx;

 	long md_c[2];

 	unsigned char local_md[MD_DIGEST_LENGTH];

 	EVP_MD_CTX m;

 	int do_not_lock;

 	/*

 	 * (Based on the rand(3) manpage)

 	 *

 	 * The input is chopped up into units of 20 bytes (or less for

 	 * the last block).  Each of these blocks is run through the hash

 	 * function as follows:  The data passed to the hash function

 	 * is the current 'md', the same number of bytes from the 'state'

 	 * (the location determined by in incremented looping index) as

 	 * the current 'block', the new key data 'block', and 'count'

 	 * (which is incremented after each use).

 	 * The result of this is kept in 'md' and also xored into the

 	 * 'state' at the same locations that were used as input into the

          * hash function.

 	 */

 	/* check if we already have the lock */

 	if (crypto_lock_rand)

 		{

 		CRYPTO_r_lock(CRYPTO_LOCK_RAND2);

 		do_not_lock = (locking_thread == CRYPTO_thread_id());

 		CRYPTO_r_unlock(CRYPTO_LOCK_RAND2);

 		}

 	else

 		do_not_lock = 0;

 	if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND);

 	st_idx=state_index;

 	/* use our own copies of the counters so that even

 	 * if a concurrent thread seeds with exactly the

 	 * same data and uses the same subarray there's _some_

 	 * difference */

 	md_c[0] = md_count[0];

 	md_c[1] = md_count[1];

 	memcpy(local_md, md, sizeof md);

 	/* state_index <= state_num <= STATE_SIZE */

 	state_index += num;

 	if (state_index >= STATE_SIZE)

 		{

 		state_index%=STATE_SIZE;

 		state_num=STATE_SIZE;

 		}

 	else if (state_num < STATE_SIZE)	

 		{

 		if (state_index > state_num)

 			state_num=state_index;

 		}

 	/* state_index <= state_num <= STATE_SIZE */

 	/* state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE]

 	 * are what we will use now, but other threads may use them

 	 * as well */

 	md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0);

 	if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND);

 	EVP_MD_CTX_init(&m);

 	for (i=0; i<num; i+=MD_DIGEST_LENGTH)

 		{

 		j=(num-i);

 		j=(j > MD_DIGEST_LENGTH)?MD_DIGEST_LENGTH:j;

 		MD_Init(&m);

 		MD_Update(&m,local_md,MD_DIGEST_LENGTH);

 		k=(st_idx+j)-STATE_SIZE;

 		if (k > 0)

 			{

 			MD_Update(&m,&(state[st_idx]),j-k);

 			MD_Update(&m,&(state[0]),k);

 			}

 		else

 			MD_Update(&m,&(state[st_idx]),j);

 		MD_Update(&m,buf,j);

 		MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));

 		MD_Final(&m,local_md);

 		md_c[1]++;

 		buf=(const char *)buf + j;

 		for (k=0; k<j; k++)

 			{

 			/* Parallel threads may interfere with this,

 			 * but always each byte of the new state is

 			 * the XOR of some previous value of its

 			 * and local_md (itermediate values may be lost).

 			 * Alway using locking could hurt performance more

 			 * than necessary given that conflicts occur only

 			 * when the total seeding is longer than the random

 			 * state. */

 			state[st_idx++]^=local_md[k];

 			if (st_idx >= STATE_SIZE)

 				st_idx=0;

 			}

 		}

 	EVP_MD_CTX_cleanup(&m);

 	if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND);

 	/* Don't just copy back local_md into md -- this could mean that

 	 * other thread's seeding remains without effect (except for

 	 * the incremented counter).  By XORing it we keep at least as

 	 * much entropy as fits into md. */

 	for (k = 0; k < (int)sizeof(md); k++)

 		{

 		md[k] ^= local_md[k];

 		}

 	if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */

 	    entropy += add;

 	if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND);

 #if !defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32)

 	assert(md_c[1] == md_count[1]);

 #endif

 	}

 static void ssleay_rand_seed(const void *buf, int num)

 	{

 	ssleay_rand_add(buf, num, (double)num);

 	}

 #ifdef EMULATOR

 GET_STATIC_VAR_FROM_TLS(stirred_pool,md_rand,volatile int)

 #define stirred_pool (*GET_WSD_VAR_NAME(stirred_pool,md_rand, s)())

 #endif

 static int ssleay_rand_bytes(unsigned char *buf, int num)

 	{

 #ifndef EMULATOR	

 	static volatile int stirred_pool = 0;

 #endif	

 	int i,j,k,st_num,st_idx;

 	int num_ceil;

 	int ok;

 	long md_c[2];

 	unsigned char local_md[MD_DIGEST_LENGTH];

 	EVP_MD_CTX m;

 #ifndef GETPID_IS_MEANINGLESS

 	pid_t curr_pid = getpid();

 #endif

 	int do_stir_pool = 0;

 #ifdef PREDICT

 	if (rand_predictable)

 		{

 		static unsigned char val=0;

 		for (i=0; i<num; i++)

 			buf[i]=val++;

 		return(1);

 		}

 #endif

 	if (num <= 0)

 		return 1;

 	EVP_MD_CTX_init(&m);

 	/* round upwards to multiple of MD_DIGEST_LENGTH/2 */

 	num_ceil = (1 + (num-1)/(MD_DIGEST_LENGTH/2)) * (MD_DIGEST_LENGTH/2);

 	/*

 	 * (Based on the rand(3) manpage:)

 	 *

 	 * For each group of 10 bytes (or less), we do the following:

 	 *

 	 * Input into the hash function the local 'md' (which is initialized from

 	 * the global 'md' before any bytes are generated), the bytes that are to

 	 * be overwritten by the random bytes, and bytes from the 'state'

 	 * (incrementing looping index). From this digest output (which is kept

 	 * in 'md'), the top (up to) 10 bytes are returned to the caller and the

 	 * bottom 10 bytes are xored into the 'state'.

 	 * 

 	 * Finally, after we have finished 'num' random bytes for the

 	 * caller, 'count' (which is incremented) and the local and global 'md'

 	 * are fed into the hash function and the results are kept in the

 	 * global 'md'.

 	 */

 	CRYPTO_w_lock(CRYPTO_LOCK_RAND);

 	/* prevent ssleay_rand_bytes() from trying to obtain the lock again */

 	CRYPTO_w_lock(CRYPTO_LOCK_RAND2);

 	locking_thread = CRYPTO_thread_id();

 	CRYPTO_w_unlock(CRYPTO_LOCK_RAND2);

 	crypto_lock_rand = 1;

 	if (!initialized)

 		{

 		RAND_poll();

 		initialized = 1;

 		}

 	if (!stirred_pool)

 		do_stir_pool = 1;

 	ok = (entropy >= ENTROPY_NEEDED);

 	if (!ok)

 		{

 		/* If the PRNG state is not yet unpredictable, then seeing

 		 * the PRNG output may help attackers to determine the new

 		 * state; thus we have to decrease the entropy estimate.

 		 * Once we've had enough initial seeding we don't bother to

 		 * adjust the entropy count, though, because we're not ambitious

 		 * to provide *information-theoretic* randomness.

 		 *

 		 * NOTE: This approach fails if the program forks before

 		 * we have enough entropy. Entropy should be collected

 		 * in a separate input pool and be transferred to the

 		 * output pool only when the entropy limit has been reached.

 		 */

 		entropy -= num;

 		if (entropy < 0)

 			entropy = 0;

 		}

 	if (do_stir_pool)

 		{

 		/* In the output function only half of 'md' remains secret,

 		 * so we better make sure that the required entropy gets

 		 * 'evenly distributed' through 'state', our randomness pool.

 		 * The input function (ssleay_rand_add) chains all of 'md',

 		 * which makes it more suitable for this purpose.

 		 */

 		int n = STATE_SIZE; /* so that the complete pool gets accessed */

 		while (n > 0)

 			{

 #if MD_DIGEST_LENGTH > 20

 # error "Please adjust DUMMY_SEED."

 #endif

 #define DUMMY_SEED "...................." /* at least MD_DIGEST_LENGTH */

 			/* Note that the seed does not matter, it's just that

 			 * ssleay_rand_add expects to have something to hash. */

 			ssleay_rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0);

 			n -= MD_DIGEST_LENGTH;

 			}

 		if (ok)

 			stirred_pool = 1;

 		}

 	st_idx=state_index;

 	st_num=state_num;

 	md_c[0] = md_count[0];

 	md_c[1] = md_count[1];

 	memcpy(local_md, md, sizeof md);

 	state_index+=num_ceil;

 	if (state_index > state_num)

 		state_index %= state_num;

 	/* state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num]

 	 * are now ours (but other threads may use them too) */

 	md_count[0] += 1;

 	/* before unlocking, we must clear 'crypto_lock_rand' */

 	crypto_lock_rand = 0;

 	CRYPTO_w_unlock(CRYPTO_LOCK_RAND);

 	while (num > 0)

 		{

 		/* num_ceil -= MD_DIGEST_LENGTH/2 */

 		j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num;

 		num-=j;

 		MD_Init(&m);

 #ifndef GETPID_IS_MEANINGLESS

 		if (curr_pid) /* just in the first iteration to save time */

 			{

 			MD_Update(&m,(unsigned char*)&curr_pid,sizeof curr_pid);

 			curr_pid = 0;

 			}

 #endif

 		MD_Update(&m,local_md,MD_DIGEST_LENGTH);

 		MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));

 #ifndef PURIFY

 		MD_Update(&m,buf,j); /* purify complains */

 #endif

 		k=(st_idx+MD_DIGEST_LENGTH/2)-st_num;

 		if (k > 0)

 			{

 			MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2-k);

 			MD_Update(&m,&(state[0]),k);

 			}

 		else

 			MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2);

 		MD_Final(&m,local_md);

 		for (i=0; i<MD_DIGEST_LENGTH/2; i++)

 			{

 			state[st_idx++]^=local_md[i]; /* may compete with other threads */

 			if (st_idx >= st_num)

 				st_idx=0;

 			if (i < j)

 				*(buf++)=local_md[i+MD_DIGEST_LENGTH/2];

 			}

 		}

 	MD_Init(&m);

 	MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));

 	MD_Update(&m,local_md,MD_DIGEST_LENGTH);

 	CRYPTO_w_lock(CRYPTO_LOCK_RAND);

 	MD_Update(&m,md,MD_DIGEST_LENGTH);

 	MD_Final(&m,md);

 	CRYPTO_w_unlock(CRYPTO_LOCK_RAND);

 	EVP_MD_CTX_cleanup(&m);

 	if (ok)

 		return(1);

 	else

 		{

 		RANDerr(RAND_F_SSLEAY_RAND_BYTES,RAND_R_PRNG_NOT_SEEDED);

 		ERR_add_error_data(1, "You need to read the OpenSSL FAQ, "

 			"http://www.openssl.org/support/faq.html");

 		return(0);

 		}

 	}

 /* pseudo-random bytes that are guaranteed to be unique but not

    unpredictable */

 static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) 

 	{

 	int ret;

 	unsigned long err;

 	ret = RAND_bytes(buf, num);

 	if (ret == 0)

 		{

 		err = ERR_peek_error();

 		if (ERR_GET_LIB(err) == ERR_LIB_RAND &&

 		    ERR_GET_REASON(err) == RAND_R_PRNG_NOT_SEEDED)

 			ERR_clear_error();

 		}

 	return (ret);

 	}

 static int ssleay_rand_status(void)

 	{

 	int ret;

 	int do_not_lock;

 	/* check if we already have the lock

 	 * (could happen if a RAND_poll() implementation calls RAND_status()) */

 	if (crypto_lock_rand)

 		{

 		CRYPTO_r_lock(CRYPTO_LOCK_RAND2);

 		do_not_lock = (locking_thread == CRYPTO_thread_id());

 		CRYPTO_r_unlock(CRYPTO_LOCK_RAND2);

 		}

 	else

 		do_not_lock = 0;

 	if (!do_not_lock)

 		{

 		CRYPTO_w_lock(CRYPTO_LOCK_RAND);

 		/* prevent ssleay_rand_bytes() from trying to obtain the lock again */

 		CRYPTO_w_lock(CRYPTO_LOCK_RAND2);

 		locking_thread = CRYPTO_thread_id();

 		CRYPTO_w_unlock(CRYPTO_LOCK_RAND2);

 		crypto_lock_rand = 1;

 		}

 	if (!initialized)

 		{

 		RAND_poll();

 		initialized = 1;

 		}

 	ret = entropy >= ENTROPY_NEEDED;

 	if (!do_not_lock)

 		{

 		/* before unlocking, we must clear 'crypto_lock_rand' */

 		crypto_lock_rand = 0;

 		CRYPTO_w_unlock(CRYPTO_LOCK_RAND);

 		}

 	return ret;

 	}