crypto/rand/rand_lib.c

   1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   2  * All rights reserved.
   3  *
   4  * This package is an SSL implementation written
   5  * by Eric Young (eay@cryptsoft.com).
   6  * The implementation was written so as to conform with Netscapes SSL.
   7  *
   8  * This library is free for commercial and non-commercial use as long as
   9  * the following conditions are aheared to.  The following conditions
  10  * apply to all code found in this distribution, be it the RC4, RSA,
  11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  12  * included with this distribution is covered by the same copyright terms
  13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  14  *
  15  * Copyright remains Eric Young's, and as such any Copyright notices in
  16  * the code are not to be removed.
  17  * If this package is used in a product, Eric Young should be given attribution
  18  * as the author of the parts of the library used.
  19  * This can be in the form of a textual message at program startup or
  20  * in documentation (online or textual) provided with the package.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. All advertising materials mentioning features or use of this software
  31  *    must display the following acknowledgement:
  32  *    "This product includes cryptographic software written by
  33  *     Eric Young (eay@cryptsoft.com)"
  34  *    The word 'cryptographic' can be left out if the rouines from the library
  35  *    being used are not cryptographic related :-).
  36  * 4. If you include any Windows specific code (or a derivative thereof) from
  37  *    the apps directory (application code) you must include an acknowledgement:
  38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  *
  52  * The licence and distribution terms for any publically available version or
  53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  54  * copied and put under another distribution licence
  55  * [including the GNU Public Licence.]
  56  */
  57
  58 #include <stdio.h>
  59 #include <time.h>
  60 #include "internal/cryptlib.h"
  61 #include <openssl/opensslconf.h>
  62 #include "internal/rand.h"
  63
  64 #include <openssl/engine.h>
  65
  66 #ifdef OPENSSL_FIPS
  67 # include <openssl/fips.h>
  68 # include <openssl/fips_rand.h>
  69 #endif
  70
  71 #ifndef OPENSSL_NO_ENGINE
  72 /* non-NULL if default_RAND_meth is ENGINE-provided */
  73 static ENGINE *funct_ref = NULL;
  74 #endif
  75 static const RAND_METHOD *default_RAND_meth = NULL;
  76
  77 int RAND_set_rand_method(const RAND_METHOD *meth)
  78 {
  79 #ifndef OPENSSL_NO_ENGINE
  80     ENGINE_finish(funct_ref);
  81     funct_ref = NULL;
  82 #endif
  83     default_RAND_meth = meth;
  84     return 1;
  85 }
  86
  87 const RAND_METHOD *RAND_get_rand_method(void)
  88 {
  89     if (!default_RAND_meth) {
  90 #ifndef OPENSSL_NO_ENGINE
  91         ENGINE *e = ENGINE_get_default_RAND();
  92         if (e) {
  93             default_RAND_meth = ENGINE_get_RAND(e);
  94             if (default_RAND_meth == NULL) {
  95                 ENGINE_finish(e);
  96                 e = NULL;
  97             }
  98         }
  99         if (e)
 100             funct_ref = e;
 101         else
 102 #endif
 103             default_RAND_meth = RAND_OpenSSL();
 104     }
 105     return default_RAND_meth;
 106 }
 107
 108 #ifndef OPENSSL_NO_ENGINE
 109 int RAND_set_rand_engine(ENGINE *engine)
 110 {
 111     const RAND_METHOD *tmp_meth = NULL;
 112     if (engine) {
 113         if (!ENGINE_init(engine))
 114             return 0;
 115         tmp_meth = ENGINE_get_RAND(engine);
 116         if (tmp_meth == NULL) {
 117             ENGINE_finish(engine);
 118             return 0;
 119         }
 120     }
 121     /* This function releases any prior ENGINE so call it first */
 122     RAND_set_rand_method(tmp_meth);
 123     funct_ref = engine;
 124     return 1;
 125 }
 126 #endif
 127
 128 void int_rand_cleanup(void)
 129 {
 130     const RAND_METHOD *meth = RAND_get_rand_method();
 131     if (meth && meth->cleanup)
 132         meth->cleanup();
 133     RAND_set_rand_method(NULL);
 134 }
 135
 136 void RAND_seed(const void *buf, int num)
 137 {
 138     const RAND_METHOD *meth = RAND_get_rand_method();
 139     if (meth && meth->seed)
 140         meth->seed(buf, num);
 141 }
 142
 143 void RAND_add(const void *buf, int num, double entropy)
 144 {
 145     const RAND_METHOD *meth = RAND_get_rand_method();
 146     if (meth && meth->add)
 147         meth->add(buf, num, entropy);
 148 }
 149
 150 int RAND_bytes(unsigned char *buf, int num)
 151 {
 152     const RAND_METHOD *meth = RAND_get_rand_method();
 153     if (meth && meth->bytes)
 154         return meth->bytes(buf, num);
 155     return (-1);
 156 }
 157
 158 #if OPENSSL_API_COMPAT < 0x10100000L
 159 int RAND_pseudo_bytes(unsigned char *buf, int num)
 160 {
 161     const RAND_METHOD *meth = RAND_get_rand_method();
 162     if (meth && meth->pseudorand)
 163         return meth->pseudorand(buf, num);
 164     return (-1);
 165 }
 166 #endif
 167
 168 int RAND_status(void)
 169 {
 170     const RAND_METHOD *meth = RAND_get_rand_method();
 171     if (meth && meth->status)
 172         return meth->status();
 173     return 0;
 174 }