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
  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 #ifdef OPENSSL_FIPS
  82         if (!FIPS_rand_set_method(meth))
  83                 return 0;
  84 #endif
  85 #ifndef OPENSSL_NO_ENGINE
  86         if(funct_ref)
  87                 {
  88                 ENGINE_finish(funct_ref);
  89                 funct_ref = NULL;
  90                 }
  91 #endif
  92         default_RAND_meth = meth;
  93         return 1;
  94         }
  95
  96 const RAND_METHOD *RAND_get_rand_method(void)
  97         {
  98         if (!default_RAND_meth)
  99                 {
 100 #ifndef OPENSSL_NO_ENGINE
 101                 ENGINE *e = ENGINE_get_default_RAND();
 102                 if(e)
 103                         {
 104                         default_RAND_meth = ENGINE_get_RAND(e);
 105                         if(!default_RAND_meth)
 106                                 {
 107                                 ENGINE_finish(e);
 108                                 e = NULL;
 109                                 }
 110                         }
 111                 if(e)
 112                         funct_ref = e;
 113                 else
 114 #endif
 115                         default_RAND_meth = RAND_SSLeay();
 116                 }
 117         return default_RAND_meth;
 118         }
 119
 120 #ifndef OPENSSL_NO_ENGINE
 121 int RAND_set_rand_engine(ENGINE *engine)
 122         {
 123         const RAND_METHOD *tmp_meth = NULL;
 124         if(engine)
 125                 {
 126                 if(!ENGINE_init(engine))
 127                         return 0;
 128                 tmp_meth = ENGINE_get_RAND(engine);
 129                 if(!tmp_meth)
 130                         {
 131                         ENGINE_finish(engine);
 132                         return 0;
 133                         }
 134                 }
 135         /* This function releases any prior ENGINE so call it first */
 136         RAND_set_rand_method(tmp_meth);
 137         funct_ref = engine;
 138         return 1;
 139         }
 140 #endif
 141
 142 void RAND_cleanup(void)
 143         {
 144         const RAND_METHOD *meth = RAND_get_rand_method();
 145         if (meth && meth->cleanup)
 146                 meth->cleanup();
 147         RAND_set_rand_method(NULL);
 148         }
 149
 150 void RAND_seed(const void *buf, int num)
 151         {
 152         const RAND_METHOD *meth = RAND_get_rand_method();
 153         if (meth && meth->seed)
 154                 meth->seed(buf,num);
 155         }
 156
 157 void RAND_add(const void *buf, int num, double entropy)
 158         {
 159         const RAND_METHOD *meth = RAND_get_rand_method();
 160         if (meth && meth->add)
 161                 meth->add(buf,num,entropy);
 162         }
 163
 164 int RAND_bytes(unsigned char *buf, int num)
 165         {
 166         const RAND_METHOD *meth = RAND_get_rand_method();
 167         if (meth && meth->bytes)
 168                 return meth->bytes(buf,num);
 169         return(-1);
 170         }
 171
 172 int RAND_pseudo_bytes(unsigned char *buf, int num)
 173         {
 174         const RAND_METHOD *meth = RAND_get_rand_method();
 175         if (meth && meth->pseudorand)
 176                 return meth->pseudorand(buf,num);
 177         return(-1);
 178         }
 179
 180 int RAND_status(void)
 181         {
 182         const RAND_METHOD *meth = RAND_get_rand_method();
 183         if (meth && meth->status)
 184                 return meth->status();
 185         return 0;
 186         }
 187
 188 #ifdef OPENSSL_FIPS
 189
 190 /* FIPS DRBG initialisation code. This sets up the DRBG for use by the
 191  * rest of OpenSSL.
 192  */
 193
 194 /* Entropy gatherer: use standard OpenSSL PRNG to seed (this will gather
 195  * entropy internally through RAND_poll().
 196  */
 197
 198 static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout,
 199                                 int entropy, size_t min_len, size_t max_len)
 200         {
 201         *pout = OPENSSL_malloc(min_len);
 202         if (!*pout)
 203                 return 0;
 204         if (RAND_SSLeay()->bytes(*pout, min_len) <= 0)
 205                 {
 206                 OPENSSL_free(*pout);
 207                 *pout = NULL;
 208                 return 0;
 209                 }
 210         return min_len;
 211         }
 212
 213 static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen)
 214         {
 215         OPENSSL_cleanse(out, olen);
 216         OPENSSL_free(out);
 217         }
 218
 219 /* Set "additional input" when generating random data. This uses the
 220  * current PID, a time value and a counter.
 221  */
 222
 223 static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout)
 224         {
 225         /* Use of static variables is OK as this happens under a lock */
 226         static unsigned char buf[16];
 227         static unsigned long counter;
 228         FIPS_get_timevec(buf, &counter);
 229         *pout = buf;
 230         return sizeof(buf);
 231         }
 232
 233 /* RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is
 234  * correctly seeded by RAND_poll().
 235  */
 236
 237 static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen,
 238                                 double entropy)
 239         {
 240         return RAND_SSLeay()->add(in, inlen, entropy);
 241         }
 242
 243 static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen)
 244         {
 245         return RAND_SSLeay()->seed(in, inlen);
 246         }
 247
 248 int RAND_init_fips(void)
 249         {
 250         DRBG_CTX *dctx;
 251         size_t plen;
 252         unsigned char pers[32], *p;
 253         dctx = FIPS_get_default_drbg();
 254         FIPS_drbg_init(dctx, NID_aes_256_ctr, DRBG_FLAG_CTR_USE_DF);
 255         FIPS_drbg_set_callbacks(dctx,
 256                                 drbg_get_entropy, drbg_free_entropy,
 257                                 drbg_get_entropy, drbg_free_entropy);
 258         FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0,
 259                                         drbg_rand_seed, drbg_rand_add);
 260         /* Personalisation string: a string followed by date time vector */
 261         strcpy((char *)pers, "OpenSSL DRBG2.0");
 262         plen = drbg_get_adin(dctx, &p);
 263         memcpy(pers + 16, p, plen);
 264
 265         FIPS_drbg_instantiate(dctx, pers, sizeof(pers));
 266         FIPS_rand_set_method(FIPS_drbg_method());
 267         return 1;
 268         }
 269
 270 #endif