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 int FIPS_drbg_reseed(DRBG_CTX *dctx,
 277                         const unsigned char *adin, size_t adinlen)
 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
 307         entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
 308                                 dctx->min_entropy, dctx->max_entropy);
 309
 310         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 311                 {
 312                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 313                 goto end;
 314                 }
 315
 316         if (!dctx->reseed(dctx, entropy, entlen, adin, adinlen))
 317                 goto end;
 318
 319         dctx->status = DRBG_STATUS_READY;
 320         if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
 321                 dctx->reseed_counter = 1;
 322         end:
 323
 324         if (entropy && dctx->cleanup_entropy)
 325                 fips_cleanup_entropy(dctx, entropy, entlen);
 326
 327         if (dctx->status == DRBG_STATUS_READY)
 328                 return 1;
 329
 330         if (r && !(dctx->iflags & DRBG_FLAG_NOERR))
 331                 FIPSerr(FIPS_F_FIPS_DRBG_RESEED, r);
 332
 333         return 0;
 334         }
 335
 336 static int fips_drbg_check(DRBG_CTX *dctx)
 337         {
 338         if (dctx->xflags & DRBG_FLAG_TEST)
 339                 return 1;
 340         dctx->health_check_cnt++;
 341         if (dctx->health_check_cnt >= dctx->health_check_interval)
 342                 {
 343                 if (FIPS_drbg_test(dctx) <= 0)
 344                         {
 345                         FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);
 346                         dctx->status = DRBG_STATUS_ERROR;
 347                         return 0;
 348                         }
 349                 dctx->health_check_cnt = 0;
 350                 }
 351         return 1;
 352         }
 353
 354 int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 355                         int prediction_resistance,
 356                         const unsigned char *adin, size_t adinlen)
 357         {
 358         int r = 0;
 359
 360         if (!fips_drbg_check(dctx))
 361                 return 0;
 362
 363         if (dctx->status != DRBG_STATUS_READY
 364                 && dctx->status != DRBG_STATUS_RESEED)
 365                 {
 366                 if (dctx->status == DRBG_STATUS_ERROR)
 367                         r = FIPS_R_IN_ERROR_STATE;
 368                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 369                         r = FIPS_R_NOT_INSTANTIATED;
 370                 goto end;
 371                 }
 372
 373         if (outlen > dctx->max_request)
 374                 {
 375                 r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
 376                 return 0;
 377                 }
 378
 379         if (adinlen > dctx->max_adin)
 380                 {
 381                 r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
 382                 goto end;
 383                 }
 384
 385         if (dctx->iflags & DRBG_CUSTOM_RESEED)
 386                 dctx->generate(dctx, NULL, outlen, NULL, 0);
 387         else if (dctx->reseed_counter >= dctx->reseed_interval)
 388                 dctx->status = DRBG_STATUS_RESEED;
 389
 390         if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)
 391                 {
 392                 if (!FIPS_drbg_reseed(dctx, adin, adinlen))
 393                         {
 394                         r = FIPS_R_RESEED_ERROR;
 395                         goto end;
 396                         }
 397                 adin = NULL;
 398                 adinlen = 0;
 399                 }
 400
 401         if (!dctx->generate(dctx, out, outlen, adin, adinlen))
 402                 {
 403                 r = FIPS_R_GENERATE_ERROR;
 404                 dctx->status = DRBG_STATUS_ERROR;
 405                 goto end;
 406                 }
 407         if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
 408                 {
 409                 if (dctx->reseed_counter >= dctx->reseed_interval)
 410                         dctx->status = DRBG_STATUS_RESEED;
 411                 else
 412                         dctx->reseed_counter++;
 413                 }
 414
 415         end:
 416         if (r)
 417                 {
 418                 if (!(dctx->iflags & DRBG_FLAG_NOERR))
 419                         FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
 420                 return 0;
 421                 }
 422
 423         return 1;
 424         }
 425
 426 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
 427         {
 428         int rv;
 429         if (!dctx->uninstantiate)
 430                 rv = 1;
 431         else
 432                 rv = dctx->uninstantiate(dctx);
 433         /* Although we'd like to cleanse here we can't because we have to
 434          * test the uninstantiate really zeroes the data.
 435          */
 436         memset(&dctx->d, 0, sizeof(dctx->d));
 437         dctx->status = DRBG_STATUS_UNINITIALISED;
 438         /* If method has problems uninstantiating, return error */
 439         return rv;
 440         }
 441
 442 int FIPS_drbg_set_callbacks(DRBG_CTX *dctx,
 443         size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char **pout,
 444                                 int entropy, size_t min_len, size_t max_len),
 445         void (*cleanup_entropy)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 446         size_t entropy_blocklen,
 447         size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char **pout,
 448                                 int entropy, size_t min_len, size_t max_len),
 449         void (*cleanup_nonce)(DRBG_CTX *ctx, unsigned char *out, size_t olen))
 450         {
 451         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 452                 return 0;
 453         dctx->entropy_blocklen = entropy_blocklen;
 454         dctx->get_entropy = get_entropy;
 455         dctx->cleanup_entropy = cleanup_entropy;
 456         dctx->get_nonce = get_nonce;
 457         dctx->cleanup_nonce = cleanup_nonce;
 458         return 1;
 459         }
 460
 461 int FIPS_drbg_set_rand_callbacks(DRBG_CTX *dctx,
 462         size_t (*get_adin)(DRBG_CTX *ctx, unsigned char **pout),
 463         void (*cleanup_adin)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 464         int (*rand_seed_cb)(DRBG_CTX *ctx, const void *buf, int num),
 465         int (*rand_add_cb)(DRBG_CTX *ctx,
 466                                 const void *buf, int num, double entropy))
 467         {
 468         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 469                 return 0;
 470         dctx->get_adin = get_adin;
 471         dctx->cleanup_adin = cleanup_adin;
 472         dctx->rand_seed_cb = rand_seed_cb;
 473         dctx->rand_add_cb = rand_add_cb;
 474         return 1;
 475         }
 476
 477 void *FIPS_drbg_get_app_data(DRBG_CTX *dctx)
 478         {
 479         return dctx->app_data;
 480         }
 481
 482 void FIPS_drbg_set_app_data(DRBG_CTX *dctx, void *app_data)
 483         {
 484         dctx->app_data = app_data;
 485         }
 486
 487 size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx)
 488         {
 489         return dctx->blocklength;
 490         }
 491
 492 int FIPS_drbg_get_strength(DRBG_CTX *dctx)
 493         {
 494         return dctx->strength;
 495         }
 496
 497 void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval)
 498         {
 499         dctx->health_check_interval = interval;
 500         }
 501
 502 void FIPS_drbg_set_reseed_interval(DRBG_CTX *dctx, int interval)
 503         {
 504         dctx->reseed_interval = interval;
 505         }
 506
 507 static int drbg_stick = 0;
 508
 509 void FIPS_drbg_stick(void)
 510         {
 511         drbg_stick = 1;
 512         }
 513
 514 /* Continuous DRBG utility function */
 515 int fips_drbg_cprng_test(DRBG_CTX *dctx, const unsigned char *out)
 516         {
 517         /* No CPRNG in test mode */
 518         if (dctx->xflags & DRBG_FLAG_TEST)
 519                 return 1;
 520         /* Check block is valid: should never happen */
 521         if (dctx->lb_valid == 0)
 522                 {
 523                 FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_INTERNAL_ERROR);
 524                 fips_set_selftest_fail();
 525                 return 0;
 526                 }
 527         if (drbg_stick)
 528                 memcpy(dctx->lb, out, dctx->blocklength);
 529         /* Check against last block: fail if match */
 530         if (!memcmp(dctx->lb, out, dctx->blocklength))
 531                 {
 532                 FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_DRBG_STUCK);
 533                 fips_set_selftest_fail();
 534                 return 0;
 535                 }
 536         /* Save last block for next comparison */
 537         memcpy(dctx->lb, out, dctx->blocklength);
 538         return 1;
 539         }