src/parsec/disk-image/parsec/parsec-benchmark/pkgs/libs/ssl/src/crypto/rand/md_rand.c - public/gem5-resources - Git at Google

 /* 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).
  *
  */

 #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>
 #ifdef OPENSSL_FIPS
 #include <openssl/fips.h>
 #endif


 #ifdef BN_DEBUG
 # define PREDICT
 #endif

 /* #define PREDICT	1 */

 #define STATE_SIZE	1023
 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 */


 #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);

 RAND_METHOD rand_ssleay_meth={
 	ssleay_rand_seed,
 	ssleay_rand_bytes,
 	ssleay_rand_cleanup,
 	ssleay_rand_add,
 	ssleay_rand_pseudo_bytes,
 	ssleay_rand_status
 	};

 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);
 	}

 static int ssleay_rand_bytes(unsigned char *buf, int num)
 	{
 	static volatile int stirred_pool = 0;
 	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 OPENSSL_FIPS
 	if(FIPS_mode())
 	    {
 	    FIPSerr(FIPS_F_SSLEAY_RAND_BYTES,FIPS_R_NON_FIPS_METHOD);
 	    return 0;
 	    }
 #endif

 #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;
 	}
	/* 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).
	*
	*/

	#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>
	#ifdef OPENSSL_FIPS
	#include <openssl/fips.h>
	#endif


	#ifdef BN_DEBUG
	# define PREDICT
	#endif

	/* #define PREDICT 1 */

	#define STATE_SIZE 1023
	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 */


	#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);

	RAND_METHOD rand_ssleay_meth={
	ssleay_rand_seed,
	ssleay_rand_bytes,
	ssleay_rand_cleanup,
	ssleay_rand_add,
	ssleay_rand_pseudo_bytes,
	ssleay_rand_status
	};

	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);
	}

	static int ssleay_rand_bytes(unsigned char *buf, int num)
	{
	static volatile int stirred_pool = 0;
	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 OPENSSL_FIPS
	if(FIPS_mode())
	{
	FIPSerr(FIPS_F_SSLEAY_RAND_BYTES,FIPS_R_NON_FIPS_METHOD);
	return 0;
	}
	#endif

	#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;
	}