fips/rand/fips_drbg_lib.c

   1 /* fips/rand/fips_drbg_lib.c */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2011 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  */
  53
  54 #define OPENSSL_FIPSAPI
  55
  56 #include <string.h>
  57 #include <openssl/crypto.h>
  58 #include <openssl/evp.h>
  59 #include <openssl/aes.h>
  60 #include <openssl/err.h>
  61 #include <openssl/fips_rand.h>
  62 #include "fips_rand_lcl.h"
  63
  64 /* Support framework for SP800-90 DRBGs */
  65
  66 int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
  67         {
  68         int rv;
  69         memset(dctx, 0, sizeof(DRBG_CTX));
  70         dctx->status = DRBG_STATUS_UNINITIALISED;
  71         dctx->flags = flags;
  72         dctx->type = type;
  73
  74         dctx->health_check_cnt = 0;
  75         dctx->health_check_interval = DRBG_HEALTH_INTERVAL;
  76
  77         rv = fips_drbg_hash_init(dctx);
  78
  79         if (rv == -2)
  80                 rv = fips_drbg_ctr_init(dctx);
  81
  82         if (rv <= 0)
  83                 {
  84                 if (rv == -2)
  85                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_UNSUPPORTED_DRBG_TYPE);
  86                 else
  87                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_ERROR_INITIALISING_DRBG);
  88                 }
  89
  90         /* If not in test mode run selftests on DRBG of the same type */
  91
  92         if (!(dctx->flags & DRBG_FLAG_TEST))
  93                 {
  94                 DRBG_CTX tctx;
  95                 if (!fips_drbg_kat(&tctx, type, flags | DRBG_FLAG_TEST))
  96                         {
  97                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_SELFTEST_FAILURE);
  98                         return 0;
  99                         }
 100                 }
 101
 102         return rv;
 103         }
 104
 105 DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
 106         {
 107         DRBG_CTX *dctx;
 108         dctx = OPENSSL_malloc(sizeof(DRBG_CTX));
 109         if (!dctx)
 110                 {
 111                 FIPSerr(FIPS_F_FIPS_DRBG_NEW, ERR_R_MALLOC_FAILURE);
 112                 return NULL;
 113                 }
 114         if (type == 0)
 115                 return dctx;
 116
 117         if (FIPS_drbg_init(dctx, type, flags) <= 0)
 118                 {
 119                 OPENSSL_free(dctx);
 120                 return NULL;
 121                 }
 122
 123         return dctx;
 124         }
 125
 126 void FIPS_drbg_free(DRBG_CTX *dctx)
 127         {
 128         if (dctx->uninstantiate)
 129                 dctx->uninstantiate(dctx);
 130         OPENSSL_cleanse(&dctx->d, sizeof(dctx->d));
 131         OPENSSL_free(dctx);
 132         }
 133
 134 int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 135                                 const unsigned char *pers, size_t perslen)
 136         {
 137         size_t entlen = 0, noncelen = 0;
 138         unsigned char *nonce = NULL, *entropy = NULL;
 139
 140 #if 0
 141         /* Put here so error script picks them up */
 142         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE,
 143                                 FIPS_R_PERSONALISATION_STRING_TOO_LONG);
 144         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_IN_ERROR_STATE);
 145         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ALREADY_INSTANTIATED);
 146         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_ENTROPY);
 147         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_NONCE);
 148         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_INSTANTIATE_ERROR);
 149 #endif
 150
 151         int r = 0;
 152
 153         if (perslen > dctx->max_pers)
 154                 {
 155                 r = FIPS_R_PERSONALISATION_STRING_TOO_LONG;
 156                 goto end;
 157                 }
 158
 159         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 160                 {
 161                 if (dctx->status == DRBG_STATUS_ERROR)
 162                         r = FIPS_R_IN_ERROR_STATE;
 163                 else
 164                         r = FIPS_R_ALREADY_INSTANTIATED;
 165                 goto end;
 166                 }
 167
 168         dctx->status = DRBG_STATUS_ERROR;
 169
 170         entlen = dctx->get_entropy(dctx, &entropy, dctx->strength,
 171                                 dctx->min_entropy, dctx->max_entropy);
 172
 173         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 174                 {
 175                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 176                 goto end;
 177                 }
 178
 179         if (dctx->max_nonce > 0)
 180                 {
 181                 noncelen = dctx->get_nonce(dctx, &nonce,
 182                                         dctx->strength / 2,
 183                                         dctx->min_nonce, dctx->max_nonce);
 184
 185                 if (noncelen < dctx->min_nonce || noncelen > dctx->max_nonce)
 186                         {
 187                         r = FIPS_R_ERROR_RETRIEVING_NONCE;
 188                         goto end;
 189                         }
 190
 191                 }
 192
 193         if (!dctx->instantiate(dctx,
 194                                 entropy, entlen,
 195                                 nonce, noncelen,
 196                                 pers, perslen))
 197                 {
 198                 r = FIPS_R_ERROR_INSTANTIATING_DRBG;
 199                 goto end;
 200                 }
 201
 202
 203         dctx->status = DRBG_STATUS_READY;
 204         dctx->reseed_counter = 1;
 205
 206         end:
 207
 208         if (entropy && dctx->cleanup_entropy)
 209                 dctx->cleanup_entropy(dctx, entropy, entlen);
 210
 211         if (nonce && dctx->cleanup_nonce)
 212                 dctx->cleanup_nonce(dctx, nonce, noncelen);
 213
 214         if (dctx->status == DRBG_STATUS_READY)
 215                 return 1;
 216
 217         if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 218                 FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, r);
 219
 220         return 0;
 221
 222         }
 223
 224 int FIPS_drbg_reseed(DRBG_CTX *dctx,
 225                         const unsigned char *adin, size_t adinlen)
 226         {
 227         unsigned char *entropy = NULL;
 228         size_t entlen;
 229         int r = 0;
 230
 231 #if 0
 232         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_NOT_INSTANTIATED);
 233         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_ADDITIONAL_INPUT_TOO_LONG);
 234 #endif
 235         if (dctx->status != DRBG_STATUS_READY
 236                 && dctx->status != DRBG_STATUS_RESEED)
 237                 {
 238                 if (dctx->status == DRBG_STATUS_ERROR)
 239                         r = FIPS_R_IN_ERROR_STATE;
 240                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 241                         r = FIPS_R_NOT_INSTANTIATED;
 242                 goto end;
 243                 }
 244
 245         if (!adin)
 246                 adinlen = 0;
 247         else if (adinlen > dctx->max_adin)
 248                 {
 249                 r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
 250                 goto end;
 251                 }
 252
 253         dctx->status = DRBG_STATUS_ERROR;
 254
 255         entlen = dctx->get_entropy(dctx, &entropy, dctx->strength,
 256                                 dctx->min_entropy, dctx->max_entropy);
 257
 258         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 259                 {
 260                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 261                 goto end;
 262                 }
 263
 264         if (!dctx->reseed(dctx, entropy, entlen, adin, adinlen))
 265                 goto end;
 266
 267         dctx->status = DRBG_STATUS_READY;
 268         dctx->reseed_counter = 1;
 269         end:
 270
 271         if (entropy && dctx->cleanup_entropy)
 272                 dctx->cleanup_entropy(dctx, entropy, entlen);
 273
 274         if (dctx->status == DRBG_STATUS_READY)
 275                 return 1;
 276
 277         if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 278                 FIPSerr(FIPS_F_FIPS_DRBG_RESEED, r);
 279
 280         return 0;
 281         }
 282
 283 static int fips_drbg_check(DRBG_CTX *dctx)
 284         {
 285         if (dctx->flags & DRBG_FLAG_TEST)
 286                 return 1;
 287         dctx->health_check_cnt++;
 288         if (dctx->health_check_cnt >= dctx->health_check_interval)
 289                 {
 290                 DRBG_CTX tctx;
 291                 if (!fips_drbg_kat(&tctx, dctx->type,
 292                                                 dctx->flags | DRBG_FLAG_TEST))
 293                         {
 294                         FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);
 295                         return 0;
 296                         }
 297                 dctx->health_check_cnt = 0;
 298                 }
 299         return 1;
 300         }
 301
 302 int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 303                         int strength, int prediction_resistance,
 304                         const unsigned char *adin, size_t adinlen)
 305         {
 306         int r = 0;
 307
 308         if (!fips_drbg_check(dctx))
 309                 return 0;
 310
 311         if (dctx->status != DRBG_STATUS_READY
 312                 && dctx->status != DRBG_STATUS_RESEED)
 313                 {
 314                 if (dctx->status == DRBG_STATUS_ERROR)
 315                         r = FIPS_R_IN_ERROR_STATE;
 316                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 317                         r = FIPS_R_NOT_INSTANTIATED;
 318                 goto end;
 319                 }
 320
 321         if (outlen > dctx->max_request)
 322                 {
 323                 r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
 324                 return 0;
 325                 }
 326
 327         if (strength > dctx->strength)
 328                 {
 329                 r = FIPS_R_INSUFFICIENT_SECURITY_STRENGTH;
 330                 goto end;
 331                 }
 332
 333         if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)
 334                 {
 335                 if (!FIPS_drbg_reseed(dctx, adin, adinlen))
 336                         {
 337                         r = FIPS_R_RESEED_ERROR;
 338                         goto end;
 339                         }
 340                 adin = NULL;
 341                 adinlen = 0;
 342                 }
 343
 344         if (!dctx->generate(dctx, out, outlen, adin, adinlen))
 345                 {
 346                 r = FIPS_R_GENERATE_ERROR;
 347                 dctx->status = DRBG_STATUS_ERROR;
 348                 goto end;
 349                 }
 350         if (dctx->reseed_counter >= dctx->reseed_interval)
 351                 dctx->status = DRBG_STATUS_RESEED;
 352         else
 353                 dctx->reseed_counter++;
 354
 355         end:
 356         if (r)
 357                 {
 358                 if (!(dctx->flags & DRBG_FLAG_NOERR))
 359                         FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
 360                 return 0;
 361                 }
 362
 363         return 1;
 364         }
 365
 366 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
 367         {
 368         int rv;
 369         if (!dctx->uninstantiate)
 370                 rv = 1;
 371         else
 372                 rv = dctx->uninstantiate(dctx);
 373         /* Although we'd like to cleanse here we can't because we have to
 374          * test the uninstantiate really zeroes the data.
 375          */
 376         memset(&dctx->d, 0, sizeof(dctx->d));
 377         dctx->status = DRBG_STATUS_UNINITIALISED;
 378         /* If method has problems uninstantiating, return error */
 379         return rv;
 380         }
 381
 382 int FIPS_drbg_set_callbacks(DRBG_CTX *dctx,
 383         size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char **pout,
 384                                 int entropy, size_t min_len, size_t max_len),
 385         void (*cleanup_entropy)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 386         size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char **pout,
 387                                 int entropy, size_t min_len, size_t max_len),
 388         void (*cleanup_nonce)(DRBG_CTX *ctx, unsigned char *out, size_t olen))
 389         {
 390         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 391                 return 0;
 392         dctx->get_entropy = get_entropy;
 393         dctx->cleanup_entropy = cleanup_entropy;
 394         dctx->get_nonce = get_nonce;
 395         dctx->cleanup_nonce = cleanup_nonce;
 396         return 1;
 397         }
 398
 399 int FIPS_drbg_set_rand_callbacks(DRBG_CTX *dctx,
 400         size_t (*get_adin)(DRBG_CTX *ctx, unsigned char **pout),
 401         void (*cleanup_adin)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 402         int (*rand_seed_cb)(DRBG_CTX *ctx, const void *buf, int num),
 403         int (*rand_add_cb)(DRBG_CTX *ctx,
 404                                 const void *buf, int num, double entropy))
 405         {
 406         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 407                 return 0;
 408         dctx->get_adin = get_adin;
 409         dctx->cleanup_adin = cleanup_adin;
 410         dctx->rand_seed_cb = rand_seed_cb;
 411         dctx->rand_add_cb = rand_add_cb;
 412         return 1;
 413         }
 414
 415 void *FIPS_drbg_get_app_data(DRBG_CTX *dctx)
 416         {
 417         return dctx->app_data;
 418         }
 419
 420 void FIPS_drbg_set_app_data(DRBG_CTX *dctx, void *app_data)
 421         {
 422         dctx->app_data = app_data;
 423         }
 424
 425 size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx)
 426         {
 427         return dctx->blocklength;
 428         }
 429
 430 int FIPS_drbg_get_strength(DRBG_CTX *dctx)
 431         {
 432         return dctx->strength;
 433         }
 434
 435 void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval)
 436         {
 437         dctx->health_check_interval = interval;
 438         }
 439
 440 static int drbg_stick = 0;
 441
 442 void FIPS_drbg_stick(void)
 443         {
 444         drbg_stick = 1;
 445         }
 446
 447 /* Continuous DRBG utility function */
 448 int fips_drbg_cprng_test(DRBG_CTX *dctx, const unsigned char *out)
 449         {
 450         /* No CPRNG in test mode */
 451         if (dctx->flags & DRBG_FLAG_TEST)
 452                 return 1;
 453         /* Check block is valid: should never happen */
 454         if (dctx->lb_valid == 0)
 455                 {
 456                 FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_INTERNAL_ERROR);
 457                 fips_set_selftest_fail();
 458                 return 0;
 459                 }
 460         if (drbg_stick)
 461                 memcpy(dctx->lb, out, dctx->blocklength);
 462         /* Check against last block: fail if match */
 463         if (!memcmp(dctx->lb, out, dctx->blocklength))
 464                 {
 465                 FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_DRBG_STUCK);
 466                 fips_set_selftest_fail();
 467                 return 0;
 468                 }
 469         /* Save last block for next comparison */
 470         memcpy(dctx->lb, out, dctx->blocklength);
 471         return 1;
 472         }