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 "internal/cryptlib.h"
  62 #include <openssl/opensslconf.h>
  63 #include <openssl/rand.h>
  64
  65 #ifndef OPENSSL_NO_ENGINE
  66 # include <openssl/engine.h>
  67 #endif
  68
  69 #ifdef OPENSSL_FIPS
  70 # include <openssl/fips.h>
  71 # include <openssl/fips_rand.h>
  72 #endif
  73
  74 #ifndef OPENSSL_NO_ENGINE
  75 /* non-NULL if default_RAND_meth is ENGINE-provided */
  76 static ENGINE *funct_ref = NULL;
  77 #endif
  78 static const RAND_METHOD *default_RAND_meth = NULL;
  79
  80 int RAND_set_rand_method(const RAND_METHOD *meth)
  81 {
  82 #ifndef OPENSSL_NO_ENGINE
  83     if (funct_ref) {
  84         ENGINE_finish(funct_ref);
  85         funct_ref = NULL;
  86     }
  87 #endif
  88     default_RAND_meth = meth;
  89     return 1;
  90 }
  91
  92 const RAND_METHOD *RAND_get_rand_method(void)
  93 {
  94     if (!default_RAND_meth) {
  95 #ifndef OPENSSL_NO_ENGINE
  96         ENGINE *e = ENGINE_get_default_RAND();
  97         if (e) {
  98             default_RAND_meth = ENGINE_get_RAND(e);
  99             if (!default_RAND_meth) {
 100                 ENGINE_finish(e);
 101                 e = NULL;
 102             }
 103         }
 104         if (e)
 105             funct_ref = e;
 106         else
 107 #endif
 108             default_RAND_meth = RAND_OpenSSL();
 109     }
 110     return default_RAND_meth;
 111 }
 112
 113 #ifndef OPENSSL_NO_ENGINE
 114 int RAND_set_rand_engine(ENGINE *engine)
 115 {
 116     const RAND_METHOD *tmp_meth = NULL;
 117     if (engine) {
 118         if (!ENGINE_init(engine))
 119             return 0;
 120         tmp_meth = ENGINE_get_RAND(engine);
 121         if (!tmp_meth) {
 122             ENGINE_finish(engine);
 123             return 0;
 124         }
 125     }
 126     /* This function releases any prior ENGINE so call it first */
 127     RAND_set_rand_method(tmp_meth);
 128     funct_ref = engine;
 129     return 1;
 130 }
 131 #endif
 132
 133 void RAND_cleanup(void)
 134 {
 135     const RAND_METHOD *meth = RAND_get_rand_method();
 136     if (meth && meth->cleanup)
 137         meth->cleanup();
 138     RAND_set_rand_method(NULL);
 139 }
 140
 141 void RAND_seed(const void *buf, int num)
 142 {
 143     const RAND_METHOD *meth = RAND_get_rand_method();
 144     if (meth && meth->seed)
 145         meth->seed(buf, num);
 146 }
 147
 148 void RAND_add(const void *buf, int num, double entropy)
 149 {
 150     const RAND_METHOD *meth = RAND_get_rand_method();
 151     if (meth && meth->add)
 152         meth->add(buf, num, entropy);
 153 }
 154
 155 int RAND_bytes(unsigned char *buf, int num)
 156 {
 157     const RAND_METHOD *meth = RAND_get_rand_method();
 158     if (meth && meth->bytes)
 159         return meth->bytes(buf, num);
 160     return (-1);
 161 }
 162
 163 #if OPENSSL_API_COMPAT < 0x10100000L
 164 int RAND_pseudo_bytes(unsigned char *buf, int num)
 165 {
 166     const RAND_METHOD *meth = RAND_get_rand_method();
 167     if (meth && meth->pseudorand)
 168         return meth->pseudorand(buf, num);
 169     return (-1);
 170 }
 171 #endif
 172
 173 int RAND_status(void)
 174 {
 175     const RAND_METHOD *meth = RAND_get_rand_method();
 176     if (meth && meth->status)
 177         return meth->status();
 178     return 0;
 179 }