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