crypto/rand/rand_lib.c

   1 /* crypto/rand/rand_lib.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@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@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@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@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         }