release/src/router/openssl/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 # include "rand_lcl.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_SSLeay();
 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 int RAND_pseudo_bytes(unsigned char *buf, int num)
 164 {
 165     const RAND_METHOD *meth = RAND_get_rand_method();
 166     if (meth && meth->pseudorand)
 167         return meth->pseudorand(buf, num);
 168     return (-1);
 169 }
 170
 171 int RAND_status(void)
 172 {
 173     const RAND_METHOD *meth = RAND_get_rand_method();
 174     if (meth && meth->status)
 175         return meth->status();
 176     return 0;
 177 }
 178
 179 #ifdef OPENSSL_FIPS
 180
 181 /*
 182  * FIPS DRBG initialisation code. This sets up the DRBG for use by the rest
 183  * of OpenSSL.
 184  */
 185
 186 /*
 187  * Entropy gatherer: use standard OpenSSL PRNG to seed (this will gather
 188  * entropy internally through RAND_poll().
 189  */
 190
 191 static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout,
 192                                int entropy, size_t min_len, size_t max_len)
 193 {
 194     /* Round up request to multiple of block size */
 195     min_len = ((min_len + 19) / 20) * 20;
 196     *pout = OPENSSL_malloc(min_len);
 197     if (!*pout)
 198         return 0;
 199     if (ssleay_rand_bytes(*pout, min_len, 0, 0) <= 0) {
 200         OPENSSL_free(*pout);
 201         *pout = NULL;
 202         return 0;
 203     }
 204     return min_len;
 205 }
 206
 207 static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen)
 208 {
 209     if (out) {
 210         OPENSSL_cleanse(out, olen);
 211         OPENSSL_free(out);
 212     }
 213 }
 214
 215 /*
 216  * Set "additional input" when generating random data. This uses the current
 217  * PID, a time value and a counter.
 218  */
 219
 220 static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout)
 221 {
 222     /* Use of static variables is OK as this happens under a lock */
 223     static unsigned char buf[16];
 224     static unsigned long counter;
 225     FIPS_get_timevec(buf, &counter);
 226     *pout = buf;
 227     return sizeof(buf);
 228 }
 229
 230 /*
 231  * RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is
 232  * correctly seeded by RAND_poll().
 233  */
 234
 235 static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen,
 236                          double entropy)
 237 {
 238     RAND_SSLeay()->add(in, inlen, entropy);
 239     return 1;
 240 }
 241
 242 static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen)
 243 {
 244     RAND_SSLeay()->seed(in, inlen);
 245     return 1;
 246 }
 247
 248 # ifndef OPENSSL_DRBG_DEFAULT_TYPE
 249 #  define OPENSSL_DRBG_DEFAULT_TYPE       NID_aes_256_ctr
 250 # endif
 251 # ifndef OPENSSL_DRBG_DEFAULT_FLAGS
 252 #  define OPENSSL_DRBG_DEFAULT_FLAGS      DRBG_FLAG_CTR_USE_DF
 253 # endif
 254
 255 static int fips_drbg_type = OPENSSL_DRBG_DEFAULT_TYPE;
 256 static int fips_drbg_flags = OPENSSL_DRBG_DEFAULT_FLAGS;
 257
 258 void RAND_set_fips_drbg_type(int type, int flags)
 259 {
 260     fips_drbg_type = type;
 261     fips_drbg_flags = flags;
 262 }
 263
 264 int RAND_init_fips(void)
 265 {
 266     DRBG_CTX *dctx;
 267     size_t plen;
 268     unsigned char pers[32], *p;
 269 # ifndef OPENSSL_ALLOW_DUAL_EC_DRBG
 270     if (fips_drbg_type >> 16) {
 271         RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_DUAL_EC_DRBG_DISABLED);
 272         return 0;
 273     }
 274 # endif
 275
 276     dctx = FIPS_get_default_drbg();
 277     if (FIPS_drbg_init(dctx, fips_drbg_type, fips_drbg_flags) <= 0) {
 278         RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INITIALISING_DRBG);
 279         return 0;
 280     }
 281
 282     FIPS_drbg_set_callbacks(dctx,
 283                             drbg_get_entropy, drbg_free_entropy, 20,
 284                             drbg_get_entropy, drbg_free_entropy);
 285     FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0,
 286                                  drbg_rand_seed, drbg_rand_add);
 287     /* Personalisation string: a string followed by date time vector */
 288     strcpy((char *)pers, "OpenSSL DRBG2.0");
 289     plen = drbg_get_adin(dctx, &p);
 290     memcpy(pers + 16, p, plen);
 291
 292     if (FIPS_drbg_instantiate(dctx, pers, sizeof(pers)) <= 0) {
 293         RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INSTANTIATING_DRBG);
 294         return 0;
 295     }
 296     FIPS_rand_set_method(FIPS_drbg_method());
 297     return 1;
 298 }
 299
 300 #endif