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/err.h>
  59 #include <openssl/fips_rand.h>
  60 #include "fips_rand_lcl.h"
  61
  62 /* Support framework for SP800-90 DRBGs */
  63
  64 int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
  65         {
  66         int rv;
  67         memset(dctx, 0, sizeof(DRBG_CTX));
  68         dctx->status = DRBG_STATUS_UNINITIALISED;
  69         dctx->xflags = flags;
  70         dctx->type = type;
  71
  72         dctx->iflags = 0;
  73         dctx->entropy_blocklen = 0;
  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         if (rv == -2)
  82                 rv = fips_drbg_hmac_init(dctx);
  83         if (rv == -2)
  84                 rv = fips_drbg_ec_init(dctx);
  85
  86         if (rv <= 0)
  87                 {
  88                 if (rv == -2)
  89                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_UNSUPPORTED_DRBG_TYPE);
  90                 else
  91                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_ERROR_INITIALISING_DRBG);
  92                 }
  93
  94         /* If not in test mode run selftests on DRBG of the same type */
  95
  96         if (!(dctx->xflags & DRBG_FLAG_TEST))
  97                 {
  98                 DRBG_CTX tctx;
  99                 if (!fips_drbg_kat(&tctx, type, flags | DRBG_FLAG_TEST))
 100                         {
 101                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_SELFTEST_FAILURE);
 102                         dctx->status = DRBG_STATUS_ERROR;
 103                         return 0;
 104                         }
 105                 }
 106
 107         return rv;
 108         }
 109
 110 DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
 111         {
 112         DRBG_CTX *dctx;
 113         dctx = OPENSSL_malloc(sizeof(DRBG_CTX));
 114         if (!dctx)
 115                 {
 116                 FIPSerr(FIPS_F_FIPS_DRBG_NEW, ERR_R_MALLOC_FAILURE);
 117                 return NULL;
 118                 }
 119
 120         if (type == 0)
 121                 {
 122                 memset(dctx, 0, sizeof(DRBG_CTX));
 123                 dctx->type = 0;
 124                 dctx->status = DRBG_STATUS_UNINITIALISED;
 125                 return dctx;
 126                 }
 127
 128         if (FIPS_drbg_init(dctx, type, flags) <= 0)
 129                 {
 130                 OPENSSL_free(dctx);
 131                 return NULL;
 132                 }
 133
 134         return dctx;
 135         }
 136
 137 void FIPS_drbg_free(DRBG_CTX *dctx)
 138         {
 139         if (dctx->uninstantiate)
 140                 dctx->uninstantiate(dctx);
 141         OPENSSL_cleanse(&dctx->d, sizeof(dctx->d));
 142         OPENSSL_free(dctx);
 143         }
 144
 145 static size_t fips_get_entropy(DRBG_CTX *dctx, unsigned char **pout,
 146                                 int entropy, size_t min_len, size_t max_len)
 147         {
 148         unsigned char *tout, *p;
 149         size_t bl = dctx->entropy_blocklen, rv;
 150         if (dctx->xflags & DRBG_FLAG_TEST || !bl)
 151                 return dctx->get_entropy(dctx, pout, entropy, min_len, max_len);
 152         rv = dctx->get_entropy(dctx, &tout, entropy + bl,
 153                                 min_len + bl, max_len + bl);
 154         *pout = tout + bl;
 155         if (rv < (min_len + bl) || (rv % bl))
 156                 return 0;
 157         /* Compare consecutive blocks for continuous PRNG test */
 158         for (p = tout; p < tout + rv - bl; p += bl)
 159                 {
 160                 if (!memcmp(p, p + bl, bl))
 161                         {
 162                         FIPSerr(FIPS_F_FIPS_GET_ENTROPY, FIPS_R_ENTROPY_SOURCE_STUCK);
 163                         return 0;
 164                         }
 165                 }
 166         rv -= bl;
 167         if (rv > max_len)
 168                 return max_len;
 169         return rv;
 170         }
 171
 172 static void fips_cleanup_entropy(DRBG_CTX *dctx,
 173                                         unsigned char *out, size_t olen)
 174         {
 175         size_t bl;
 176         if (dctx->xflags & DRBG_FLAG_TEST)
 177                 bl = 0;
 178         else
 179                 bl = dctx->entropy_blocklen;
 180         /* Call cleanup with original arguments */
 181         dctx->cleanup_entropy(dctx, out - bl, olen + bl);
 182         }
 183
 184
 185 int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 186                                 const unsigned char *pers, size_t perslen)
 187         {
 188         size_t entlen = 0, noncelen = 0;
 189         unsigned char *nonce = NULL, *entropy = NULL;
 190
 191 #if 0
 192         /* Put here so error script picks them up */
 193         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE,
 194                                 FIPS_R_PERSONALISATION_STRING_TOO_LONG);
 195         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_IN_ERROR_STATE);
 196         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ALREADY_INSTANTIATED);
 197         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_ENTROPY);
 198         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_NONCE);
 199         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_INSTANTIATE_ERROR);
 200 #endif
 201
 202         int r = 0;
 203
 204         if (perslen > dctx->max_pers)
 205                 {
 206                 r = FIPS_R_PERSONALISATION_STRING_TOO_LONG;
 207                 goto end;
 208                 }
 209
 210         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 211                 {
 212                 if (dctx->status == DRBG_STATUS_ERROR)
 213                         r = FIPS_R_IN_ERROR_STATE;
 214                 else
 215                         r = FIPS_R_ALREADY_INSTANTIATED;
 216                 goto end;
 217                 }
 218
 219         dctx->status = DRBG_STATUS_ERROR;
 220
 221         entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
 222                                 dctx->min_entropy, dctx->max_entropy);
 223
 224         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 225                 {
 226                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 227                 goto end;
 228                 }
 229
 230         if (dctx->max_nonce > 0)
 231                 {
 232                 noncelen = dctx->get_nonce(dctx, &nonce,
 233                                         dctx->strength / 2,
 234                                         dctx->min_nonce, dctx->max_nonce);
 235
 236                 if (noncelen < dctx->min_nonce || noncelen > dctx->max_nonce)
 237                         {
 238                         r = FIPS_R_ERROR_RETRIEVING_NONCE;
 239                         goto end;
 240                         }
 241
 242                 }
 243
 244         if (!dctx->instantiate(dctx,
 245                                 entropy, entlen,
 246                                 nonce, noncelen,
 247                                 pers, perslen))
 248                 {
 249                 r = FIPS_R_ERROR_INSTANTIATING_DRBG;
 250                 goto end;
 251                 }
 252
 253
 254         dctx->status = DRBG_STATUS_READY;
 255         if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
 256                 dctx->reseed_counter = 1;
 257
 258         end:
 259
 260         if (entropy && dctx->cleanup_entropy)
 261                 fips_cleanup_entropy(dctx, entropy, entlen);
 262
 263         if (nonce && dctx->cleanup_nonce)
 264                 dctx->cleanup_nonce(dctx, nonce, noncelen);
 265
 266         if (dctx->status == DRBG_STATUS_READY)
 267                 return 1;
 268
 269         if (r && !(dctx->iflags & DRBG_FLAG_NOERR))
 270                 FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, r);
 271
 272         return 0;
 273
 274         }
 275
 276 static int drbg_reseed(DRBG_CTX *dctx,
 277                         const unsigned char *adin, size_t adinlen, int hcheck)
 278         {
 279         unsigned char *entropy = NULL;
 280         size_t entlen;
 281         int r = 0;
 282
 283 #if 0
 284         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_NOT_INSTANTIATED);
 285         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_ADDITIONAL_INPUT_TOO_LONG);
 286 #endif
 287         if (dctx->status != DRBG_STATUS_READY
 288                 && dctx->status != DRBG_STATUS_RESEED)
 289                 {
 290                 if (dctx->status == DRBG_STATUS_ERROR)
 291                         r = FIPS_R_IN_ERROR_STATE;
 292                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 293                         r = FIPS_R_NOT_INSTANTIATED;
 294                 goto end;
 295                 }
 296
 297         if (!adin)
 298                 adinlen = 0;
 299         else if (adinlen > dctx->max_adin)
 300                 {
 301                 r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
 302                 goto end;
 303                 }
 304
 305         dctx->status = DRBG_STATUS_ERROR;
 306         /* Peform health check on all reseed operations if not a prediction
 307          * resistance request and not in test mode.
 308          */
 309         if (hcheck && !(dctx->xflags & DRBG_FLAG_TEST))
 310                 {
 311                 if (!FIPS_drbg_test(dctx))
 312                         {
 313                         r = FIPS_R_SELFTEST_FAILURE;
 314                         goto end;
 315                         }
 316                 }
 317
 318         entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
 319                                 dctx->min_entropy, dctx->max_entropy);
 320
 321         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 322                 {
 323                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 324                 goto end;
 325                 }
 326
 327         if (!dctx->reseed(dctx, entropy, entlen, adin, adinlen))
 328                 goto end;
 329
 330         dctx->status = DRBG_STATUS_READY;
 331         if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
 332                 dctx->reseed_counter = 1;
 333         end:
 334
 335         if (entropy && dctx->cleanup_entropy)
 336                 fips_cleanup_entropy(dctx, entropy, entlen);
 337
 338         if (dctx->status == DRBG_STATUS_READY)
 339                 return 1;
 340
 341         if (r && !(dctx->iflags & DRBG_FLAG_NOERR))
 342                 FIPSerr(FIPS_F_FIPS_DRBG_RESEED, r);
 343
 344         return 0;
 345         }
 346
 347 int FIPS_drbg_reseed(DRBG_CTX *dctx,
 348                         const unsigned char *adin, size_t adinlen)
 349         {
 350         return drbg_reseed(dctx, adin, adinlen, 1);
 351         }
 352
 353 static int fips_drbg_check(DRBG_CTX *dctx)
 354         {
 355         if (dctx->xflags & DRBG_FLAG_TEST)
 356                 return 1;
 357         dctx->health_check_cnt++;
 358         if (dctx->health_check_cnt >= dctx->health_check_interval)
 359                 {
 360                 if (!FIPS_drbg_test(dctx))
 361                         {
 362                         FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);
 363                         dctx->status = DRBG_STATUS_ERROR;
 364                         return 0;
 365                         }
 366                 dctx->health_check_cnt = 0;
 367                 }
 368         return 1;
 369         }
 370
 371 int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 372                         int prediction_resistance,
 373                         const unsigned char *adin, size_t adinlen)
 374         {
 375         int r = 0;
 376
 377         if (!fips_drbg_check(dctx))
 378                 return 0;
 379
 380         if (dctx->status != DRBG_STATUS_READY
 381                 && dctx->status != DRBG_STATUS_RESEED)
 382                 {
 383                 if (dctx->status == DRBG_STATUS_ERROR)
 384                         r = FIPS_R_IN_ERROR_STATE;
 385                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 386                         r = FIPS_R_NOT_INSTANTIATED;
 387                 goto end;
 388                 }
 389
 390         if (outlen > dctx->max_request)
 391                 {
 392                 r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
 393                 return 0;
 394                 }
 395
 396         if (adinlen > dctx->max_adin)
 397                 {
 398                 r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
 399                 goto end;
 400                 }
 401
 402         if (dctx->iflags & DRBG_CUSTOM_RESEED)
 403                 dctx->generate(dctx, NULL, outlen, NULL, 0);
 404         else if (dctx->reseed_counter >= dctx->reseed_interval)
 405                 dctx->status = DRBG_STATUS_RESEED;
 406
 407         if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)
 408                 {
 409                 /* If prediction resistance request don't do health check */
 410                 int hcheck = prediction_resistance ? 0 : 1;
 411
 412                 if (!drbg_reseed(dctx, adin, adinlen, hcheck))
 413                         {
 414                         r = FIPS_R_RESEED_ERROR;
 415                         goto end;
 416                         }
 417                 adin = NULL;
 418                 adinlen = 0;
 419                 }
 420
 421         if (!dctx->generate(dctx, out, outlen, adin, adinlen))
 422                 {
 423                 r = FIPS_R_GENERATE_ERROR;
 424                 dctx->status = DRBG_STATUS_ERROR;
 425                 goto end;
 426                 }
 427         if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
 428                 {
 429                 if (dctx->reseed_counter >= dctx->reseed_interval)
 430                         dctx->status = DRBG_STATUS_RESEED;
 431                 else
 432                         dctx->reseed_counter++;
 433                 }
 434
 435         end:
 436         if (r)
 437                 {
 438                 if (!(dctx->iflags & DRBG_FLAG_NOERR))
 439                         FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
 440                 return 0;
 441                 }
 442
 443         return 1;
 444         }
 445
 446 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
 447         {
 448         int rv;
 449         if (!dctx->uninstantiate)
 450                 rv = 1;
 451         else
 452                 rv = dctx->uninstantiate(dctx);
 453         /* Although we'd like to cleanse here we can't because we have to
 454          * test the uninstantiate really zeroes the data.
 455          */
 456         memset(&dctx->d, 0, sizeof(dctx->d));
 457         dctx->status = DRBG_STATUS_UNINITIALISED;
 458         /* If method has problems uninstantiating, return error */
 459         return rv;
 460         }
 461
 462 int FIPS_drbg_set_callbacks(DRBG_CTX *dctx,
 463         size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char **pout,
 464                                 int entropy, size_t min_len, size_t max_len),
 465         void (*cleanup_entropy)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 466         size_t entropy_blocklen,
 467         size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char **pout,
 468                                 int entropy, size_t min_len, size_t max_len),
 469         void (*cleanup_nonce)(DRBG_CTX *ctx, unsigned char *out, size_t olen))
 470         {
 471         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 472                 return 0;
 473         dctx->entropy_blocklen = entropy_blocklen;
 474         dctx->get_entropy = get_entropy;
 475         dctx->cleanup_entropy = cleanup_entropy;
 476         dctx->get_nonce = get_nonce;
 477         dctx->cleanup_nonce = cleanup_nonce;
 478         return 1;
 479         }
 480
 481 int FIPS_drbg_set_rand_callbacks(DRBG_CTX *dctx,
 482         size_t (*get_adin)(DRBG_CTX *ctx, unsigned char **pout),
 483         void (*cleanup_adin)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 484         int (*rand_seed_cb)(DRBG_CTX *ctx, const void *buf, int num),
 485         int (*rand_add_cb)(DRBG_CTX *ctx,
 486                                 const void *buf, int num, double entropy))
 487         {
 488         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 489                 return 0;
 490         dctx->get_adin = get_adin;
 491         dctx->cleanup_adin = cleanup_adin;
 492         dctx->rand_seed_cb = rand_seed_cb;
 493         dctx->rand_add_cb = rand_add_cb;
 494         return 1;
 495         }
 496
 497 void *FIPS_drbg_get_app_data(DRBG_CTX *dctx)
 498         {
 499         return dctx->app_data;
 500         }
 501
 502 void FIPS_drbg_set_app_data(DRBG_CTX *dctx, void *app_data)
 503         {
 504         dctx->app_data = app_data;
 505         }
 506
 507 size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx)
 508         {
 509         return dctx->blocklength;
 510         }
 511
 512 int FIPS_drbg_get_strength(DRBG_CTX *dctx)
 513         {
 514         return dctx->strength;
 515         }
 516
 517 void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval)
 518         {
 519         dctx->health_check_interval = interval;
 520         }
 521
 522 void FIPS_drbg_set_reseed_interval(DRBG_CTX *dctx, int interval)
 523         {
 524         dctx->reseed_interval = interval;
 525         }
 526
 527 static int drbg_stick = 0;
 528
 529 void FIPS_drbg_stick(void)
 530         {
 531         drbg_stick = 1;
 532         }
 533
 534 /* Continuous DRBG utility function */
 535 int fips_drbg_cprng_test(DRBG_CTX *dctx, const unsigned char *out)
 536         {
 537         /* No CPRNG in test mode */
 538         if (dctx->xflags & DRBG_FLAG_TEST)
 539                 return 1;
 540         /* Check block is valid: should never happen */
 541         if (dctx->lb_valid == 0)
 542                 {
 543                 FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_INTERNAL_ERROR);
 544                 fips_set_selftest_fail();
 545                 return 0;
 546                 }
 547         if (drbg_stick)
 548                 memcpy(dctx->lb, out, dctx->blocklength);
 549         /* Check against last block: fail if match */
 550         if (!memcmp(dctx->lb, out, dctx->blocklength))
 551                 {
 552                 FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_DRBG_STUCK);
 553                 fips_set_selftest_fail();
 554                 return 0;
 555                 }
 556         /* Save last block for next comparison */
 557         memcpy(dctx->lb, out, dctx->blocklength);
 558         return 1;
 559         }