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      1 /* crypto/rand/rand_lib.c */
      2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      3  * All rights reserved.
      4  *
      5  * This package is an SSL implementation written
      6  * by Eric Young (eay (at) cryptsoft.com).
      7  * The implementation was written so as to conform with Netscapes SSL.
      8  *
      9  * This library is free for commercial and non-commercial use as long as
     10  * the following conditions are aheared to.  The following conditions
     11  * apply to all code found in this distribution, be it the RC4, RSA,
     12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
     13  * included with this distribution is covered by the same copyright terms
     14  * except that the holder is Tim Hudson (tjh (at) cryptsoft.com).
     15  *
     16  * Copyright remains Eric Young's, and as such any Copyright notices in
     17  * the code are not to be removed.
     18  * If this package is used in a product, Eric Young should be given attribution
     19  * as the author of the parts of the library used.
     20  * This can be in the form of a textual message at program startup or
     21  * in documentation (online or textual) provided with the package.
     22  *
     23  * Redistribution and use in source and binary forms, with or without
     24  * modification, are permitted provided that the following conditions
     25  * are met:
     26  * 1. Redistributions of source code must retain the copyright
     27  *    notice, this list of conditions and the following disclaimer.
     28  * 2. Redistributions in binary form must reproduce the above copyright
     29  *    notice, this list of conditions and the following disclaimer in the
     30  *    documentation and/or other materials provided with the distribution.
     31  * 3. All advertising materials mentioning features or use of this software
     32  *    must display the following acknowledgement:
     33  *    "This product includes cryptographic software written by
     34  *     Eric Young (eay (at) cryptsoft.com)"
     35  *    The word 'cryptographic' can be left out if the rouines from the library
     36  *    being used are not cryptographic related :-).
     37  * 4. If you include any Windows specific code (or a derivative thereof) from
     38  *    the apps directory (application code) you must include an acknowledgement:
     39  *    "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)"
     40  *
     41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
     42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     51  * SUCH DAMAGE.
     52  *
     53  * The licence and distribution terms for any publically available version or
     54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
     55  * copied and put under another distribution licence
     56  * [including the GNU Public Licence.]
     57  */
     58 
     59 #include <stdio.h>
     60 #include <time.h>
     61 #include "cryptlib.h"
     62 #include <openssl/rand.h>
     63 #ifndef OPENSSL_NO_ENGINE
     64 #include <openssl/engine.h>
     65 #endif
     66 
     67 #ifndef OPENSSL_NO_ENGINE
     68 /* non-NULL if default_RAND_meth is ENGINE-provided */
     69 static ENGINE *funct_ref =NULL;
     70 #endif
     71 static const RAND_METHOD *default_RAND_meth = NULL;
     72 
     73 int RAND_set_rand_method(const RAND_METHOD *meth)
     74 	{
     75 #ifndef OPENSSL_NO_ENGINE
     76 	if(funct_ref)
     77 		{
     78 		ENGINE_finish(funct_ref);
     79 		funct_ref = NULL;
     80 		}
     81 #endif
     82 	default_RAND_meth = meth;
     83 	return 1;
     84 	}
     85 
     86 const RAND_METHOD *RAND_get_rand_method(void)
     87 	{
     88 	if (!default_RAND_meth)
     89 		{
     90 #ifndef OPENSSL_NO_ENGINE
     91 		ENGINE *e = ENGINE_get_default_RAND();
     92 		if(e)
     93 			{
     94 			default_RAND_meth = ENGINE_get_RAND(e);
     95 			if(!default_RAND_meth)
     96 				{
     97 				ENGINE_finish(e);
     98 				e = NULL;
     99 				}
    100 			}
    101 		if(e)
    102 			funct_ref = e;
    103 		else
    104 #endif
    105 			default_RAND_meth = RAND_SSLeay();
    106 		}
    107 	return default_RAND_meth;
    108 	}
    109 
    110 #ifndef OPENSSL_NO_ENGINE
    111 int RAND_set_rand_engine(ENGINE *engine)
    112 	{
    113 	const RAND_METHOD *tmp_meth = NULL;
    114 	if(engine)
    115 		{
    116 		if(!ENGINE_init(engine))
    117 			return 0;
    118 		tmp_meth = ENGINE_get_RAND(engine);
    119 		if(!tmp_meth)
    120 			{
    121 			ENGINE_finish(engine);
    122 			return 0;
    123 			}
    124 		}
    125 	/* This function releases any prior ENGINE so call it first */
    126 	RAND_set_rand_method(tmp_meth);
    127 	funct_ref = engine;
    128 	return 1;
    129 	}
    130 #endif
    131 
    132 void RAND_cleanup(void)
    133 	{
    134 	const RAND_METHOD *meth = RAND_get_rand_method();
    135 	if (meth && meth->cleanup)
    136 		meth->cleanup();
    137 	RAND_set_rand_method(NULL);
    138 	}
    139 
    140 void RAND_seed(const void *buf, int num)
    141 	{
    142 	const RAND_METHOD *meth = RAND_get_rand_method();
    143 	if (meth && meth->seed)
    144 		meth->seed(buf,num);
    145 	}
    146 
    147 void RAND_add(const void *buf, int num, double entropy)
    148 	{
    149 	const RAND_METHOD *meth = RAND_get_rand_method();
    150 	if (meth && meth->add)
    151 		meth->add(buf,num,entropy);
    152 	}
    153 
    154 int RAND_bytes(unsigned char *buf, int num)
    155 	{
    156 	const RAND_METHOD *meth = RAND_get_rand_method();
    157 	if (meth && meth->bytes)
    158 		return meth->bytes(buf,num);
    159 	return(-1);
    160 	}
    161 
    162 int RAND_pseudo_bytes(unsigned char *buf, int num)
    163 	{
    164 	const RAND_METHOD *meth = RAND_get_rand_method();
    165 	if (meth && meth->pseudorand)
    166 		return meth->pseudorand(buf,num);
    167 	return(-1);
    168 	}
    169 
    170 int RAND_status(void)
    171 	{
    172 	const RAND_METHOD *meth = RAND_get_rand_method();
    173 	if (meth && meth->status)
    174 		return meth->status();
    175 	return 0;
    176 	}
    177