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->entropy_blocklen = 0;
  75         dctx->health_check_cnt = 0;
  76         dctx->health_check_interval = DRBG_HEALTH_INTERVAL;
  77
  78         rv = fips_drbg_hash_init(dctx);
  79
  80         if (rv == -2)
  81                 rv = fips_drbg_ctr_init(dctx);
  82
  83         if (rv <= 0)
  84                 {
  85                 if (rv == -2)
  86                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_UNSUPPORTED_DRBG_TYPE);
  87                 else
  88                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_ERROR_INITIALISING_DRBG);
  89                 }
  90
  91         /* If not in test mode run selftests on DRBG of the same type */
  92
  93         if (!(dctx->flags & DRBG_FLAG_TEST))
  94                 {
  95                 DRBG_CTX tctx;
  96                 if (!fips_drbg_kat(&tctx, type, flags | DRBG_FLAG_TEST))
  97                         {
  98                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_SELFTEST_FAILURE);
  99                         return 0;
 100                         }
 101                 }
 102
 103         return rv;
 104         }
 105
 106 DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
 107         {
 108         DRBG_CTX *dctx;
 109         dctx = OPENSSL_malloc(sizeof(DRBG_CTX));
 110         if (!dctx)
 111                 {
 112                 FIPSerr(FIPS_F_FIPS_DRBG_NEW, ERR_R_MALLOC_FAILURE);
 113                 return NULL;
 114                 }
 115         if (type == 0)
 116                 return dctx;
 117
 118         if (FIPS_drbg_init(dctx, type, flags) <= 0)
 119                 {
 120                 OPENSSL_free(dctx);
 121                 return NULL;
 122                 }
 123
 124         return dctx;
 125         }
 126
 127 void FIPS_drbg_free(DRBG_CTX *dctx)
 128         {
 129         if (dctx->uninstantiate)
 130                 dctx->uninstantiate(dctx);
 131         OPENSSL_cleanse(&dctx->d, sizeof(dctx->d));
 132         OPENSSL_free(dctx);
 133         }
 134
 135 static size_t fips_get_entropy(DRBG_CTX *dctx, unsigned char **pout,
 136                                 int entropy, size_t min_len, size_t max_len)
 137         {
 138         unsigned char *tout, *p;
 139         size_t bl = dctx->entropy_blocklen, rv;
 140         if (dctx->flags & DRBG_FLAG_TEST || !bl)
 141                 return dctx->get_entropy(dctx, pout, entropy, min_len, max_len);
 142         rv = dctx->get_entropy(dctx, &tout, entropy + bl,
 143                                 min_len + bl, max_len + bl);
 144         *pout = tout + bl;
 145         if (rv < (min_len + bl) || (rv % bl))
 146                 return 0;
 147         /* Compare consecutive blocks for continuous PRNG test */
 148         for (p = tout; p < tout + rv; p += bl)
 149                 {
 150                 if (!memcmp(p, p + bl, bl))
 151                         {
 152                         FIPSerr(FIPS_F_FIPS_GET_ENTROPY, FIPS_R_ENTROPY_SOURCE_STUCK);
 153                         return 0;
 154                         }
 155                 }
 156         return rv - bl;
 157         }
 158
 159 static void fips_cleanup_entropy(DRBG_CTX *dctx,
 160                                         unsigned char *out, size_t olen)
 161         {
 162         size_t bl;
 163         if (dctx->flags & DRBG_FLAG_TEST)
 164                 bl = 0;
 165         else
 166                 bl = dctx->entropy_blocklen;
 167         /* Call cleanup with original arguments */
 168         dctx->cleanup_entropy(dctx, out - bl, olen + bl);
 169         }
 170
 171
 172 int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 173                                 const unsigned char *pers, size_t perslen)
 174         {
 175         size_t entlen = 0, noncelen = 0;
 176         unsigned char *nonce = NULL, *entropy = NULL;
 177
 178 #if 0
 179         /* Put here so error script picks them up */
 180         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE,
 181                                 FIPS_R_PERSONALISATION_STRING_TOO_LONG);
 182         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_IN_ERROR_STATE);
 183         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ALREADY_INSTANTIATED);
 184         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_ENTROPY);
 185         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_NONCE);
 186         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_INSTANTIATE_ERROR);
 187 #endif
 188
 189         int r = 0;
 190
 191         if (perslen > dctx->max_pers)
 192                 {
 193                 r = FIPS_R_PERSONALISATION_STRING_TOO_LONG;
 194                 goto end;
 195                 }
 196
 197         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 198                 {
 199                 if (dctx->status == DRBG_STATUS_ERROR)
 200                         r = FIPS_R_IN_ERROR_STATE;
 201                 else
 202                         r = FIPS_R_ALREADY_INSTANTIATED;
 203                 goto end;
 204                 }
 205
 206         dctx->status = DRBG_STATUS_ERROR;
 207
 208         entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
 209                                 dctx->min_entropy, dctx->max_entropy);
 210
 211         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 212                 {
 213                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 214                 goto end;
 215                 }
 216
 217         if (dctx->max_nonce > 0)
 218                 {
 219                 noncelen = dctx->get_nonce(dctx, &nonce,
 220                                         dctx->strength / 2,
 221                                         dctx->min_nonce, dctx->max_nonce);
 222
 223                 if (noncelen < dctx->min_nonce || noncelen > dctx->max_nonce)
 224                         {
 225                         r = FIPS_R_ERROR_RETRIEVING_NONCE;
 226                         goto end;
 227                         }
 228
 229                 }
 230
 231         if (!dctx->instantiate(dctx,
 232                                 entropy, entlen,
 233                                 nonce, noncelen,
 234                                 pers, perslen))
 235                 {
 236                 r = FIPS_R_ERROR_INSTANTIATING_DRBG;
 237                 goto end;
 238                 }
 239
 240
 241         dctx->status = DRBG_STATUS_READY;
 242         dctx->reseed_counter = 1;
 243
 244         end:
 245
 246         if (entropy && dctx->cleanup_entropy)
 247                 fips_cleanup_entropy(dctx, entropy, entlen);
 248
 249         if (nonce && dctx->cleanup_nonce)
 250                 dctx->cleanup_nonce(dctx, nonce, noncelen);
 251
 252         if (dctx->status == DRBG_STATUS_READY)
 253                 return 1;
 254
 255         if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 256                 FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, r);
 257
 258         return 0;
 259
 260         }
 261
 262 int FIPS_drbg_reseed(DRBG_CTX *dctx,
 263                         const unsigned char *adin, size_t adinlen)
 264         {
 265         unsigned char *entropy = NULL;
 266         size_t entlen;
 267         int r = 0;
 268
 269 #if 0
 270         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_NOT_INSTANTIATED);
 271         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_ADDITIONAL_INPUT_TOO_LONG);
 272 #endif
 273         if (dctx->status != DRBG_STATUS_READY
 274                 && dctx->status != DRBG_STATUS_RESEED)
 275                 {
 276                 if (dctx->status == DRBG_STATUS_ERROR)
 277                         r = FIPS_R_IN_ERROR_STATE;
 278                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 279                         r = FIPS_R_NOT_INSTANTIATED;
 280                 goto end;
 281                 }
 282
 283         if (!adin)
 284                 adinlen = 0;
 285         else if (adinlen > dctx->max_adin)
 286                 {
 287                 r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
 288                 goto end;
 289                 }
 290
 291         dctx->status = DRBG_STATUS_ERROR;
 292
 293         entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
 294                                 dctx->min_entropy, dctx->max_entropy);
 295
 296         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 297                 {
 298                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 299                 goto end;
 300                 }
 301
 302         if (!dctx->reseed(dctx, entropy, entlen, adin, adinlen))
 303                 goto end;
 304
 305         dctx->status = DRBG_STATUS_READY;
 306         dctx->reseed_counter = 1;
 307         end:
 308
 309         if (entropy && dctx->cleanup_entropy)
 310                 fips_cleanup_entropy(dctx, entropy, entlen);
 311
 312         if (dctx->status == DRBG_STATUS_READY)
 313                 return 1;
 314
 315         if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 316                 FIPSerr(FIPS_F_FIPS_DRBG_RESEED, r);
 317
 318         return 0;
 319         }
 320
 321 static int fips_drbg_check(DRBG_CTX *dctx)
 322         {
 323         if (dctx->flags & DRBG_FLAG_TEST)
 324                 return 1;
 325         dctx->health_check_cnt++;
 326         if (dctx->health_check_cnt >= dctx->health_check_interval)
 327                 {
 328                 DRBG_CTX tctx;
 329                 if (!fips_drbg_kat(&tctx, dctx->type,
 330                                                 dctx->flags | DRBG_FLAG_TEST))
 331                         {
 332                         FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);
 333                         return 0;
 334                         }
 335                 dctx->health_check_cnt = 0;
 336                 }
 337         return 1;
 338         }
 339
 340 int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 341                         int strength, int prediction_resistance,
 342                         const unsigned char *adin, size_t adinlen)
 343         {
 344         int r = 0;
 345
 346         if (!fips_drbg_check(dctx))
 347                 return 0;
 348
 349         if (dctx->status != DRBG_STATUS_READY
 350                 && dctx->status != DRBG_STATUS_RESEED)
 351                 {
 352                 if (dctx->status == DRBG_STATUS_ERROR)
 353                         r = FIPS_R_IN_ERROR_STATE;
 354                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 355                         r = FIPS_R_NOT_INSTANTIATED;
 356                 goto end;
 357                 }
 358
 359         if (outlen > dctx->max_request)
 360                 {
 361                 r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
 362                 return 0;
 363                 }
 364
 365         if (strength > dctx->strength)
 366                 {
 367                 r = FIPS_R_INSUFFICIENT_SECURITY_STRENGTH;
 368                 goto end;
 369                 }
 370
 371         if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)
 372                 {
 373                 if (!FIPS_drbg_reseed(dctx, adin, adinlen))
 374                         {
 375                         r = FIPS_R_RESEED_ERROR;
 376                         goto end;
 377                         }
 378                 adin = NULL;
 379                 adinlen = 0;
 380                 }
 381
 382         if (!dctx->generate(dctx, out, outlen, adin, adinlen))
 383                 {
 384                 r = FIPS_R_GENERATE_ERROR;
 385                 dctx->status = DRBG_STATUS_ERROR;
 386                 goto end;
 387                 }
 388         if (dctx->reseed_counter >= dctx->reseed_interval)
 389                 dctx->status = DRBG_STATUS_RESEED;
 390         else
 391                 dctx->reseed_counter++;
 392
 393         end:
 394         if (r)
 395                 {
 396                 if (!(dctx->flags & DRBG_FLAG_NOERR))
 397                         FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
 398                 return 0;
 399                 }
 400
 401         return 1;
 402         }
 403
 404 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
 405         {
 406         int rv;
 407         if (!dctx->uninstantiate)
 408                 rv = 1;
 409         else
 410                 rv = dctx->uninstantiate(dctx);
 411         /* Although we'd like to cleanse here we can't because we have to
 412          * test the uninstantiate really zeroes the data.
 413          */
 414         memset(&dctx->d, 0, sizeof(dctx->d));
 415         dctx->status = DRBG_STATUS_UNINITIALISED;
 416         /* If method has problems uninstantiating, return error */
 417         return rv;
 418         }
 419
 420 int FIPS_drbg_set_callbacks(DRBG_CTX *dctx,
 421         size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char **pout,
 422                                 int entropy, size_t min_len, size_t max_len),
 423         void (*cleanup_entropy)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 424         size_t entropy_blocklen,
 425         size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char **pout,
 426                                 int entropy, size_t min_len, size_t max_len),
 427         void (*cleanup_nonce)(DRBG_CTX *ctx, unsigned char *out, size_t olen))
 428         {
 429         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 430                 return 0;
 431         dctx->entropy_blocklen = entropy_blocklen;
 432         dctx->get_entropy = get_entropy;
 433         dctx->cleanup_entropy = cleanup_entropy;
 434         dctx->get_nonce = get_nonce;
 435         dctx->cleanup_nonce = cleanup_nonce;
 436         return 1;
 437         }
 438
 439 int FIPS_drbg_set_rand_callbacks(DRBG_CTX *dctx,
 440         size_t (*get_adin)(DRBG_CTX *ctx, unsigned char **pout),
 441         void (*cleanup_adin)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 442         int (*rand_seed_cb)(DRBG_CTX *ctx, const void *buf, int num),
 443         int (*rand_add_cb)(DRBG_CTX *ctx,
 444                                 const void *buf, int num, double entropy))
 445         {
 446         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 447                 return 0;
 448         dctx->get_adin = get_adin;
 449         dctx->cleanup_adin = cleanup_adin;
 450         dctx->rand_seed_cb = rand_seed_cb;
 451         dctx->rand_add_cb = rand_add_cb;
 452         return 1;
 453         }
 454
 455 void *FIPS_drbg_get_app_data(DRBG_CTX *dctx)
 456         {
 457         return dctx->app_data;
 458         }
 459
 460 void FIPS_drbg_set_app_data(DRBG_CTX *dctx, void *app_data)
 461         {
 462         dctx->app_data = app_data;
 463         }
 464
 465 size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx)
 466         {
 467         return dctx->blocklength;
 468         }
 469
 470 int FIPS_drbg_get_strength(DRBG_CTX *dctx)
 471         {
 472         return dctx->strength;
 473         }
 474
 475 void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval)
 476         {
 477         dctx->health_check_interval = interval;
 478         }
 479
 480 static int drbg_stick = 0;
 481
 482 void FIPS_drbg_stick(void)
 483         {
 484         drbg_stick = 1;
 485         }
 486
 487 /* Continuous DRBG utility function */
 488 int fips_drbg_cprng_test(DRBG_CTX *dctx, const unsigned char *out)
 489         {
 490         /* No CPRNG in test mode */
 491         if (dctx->flags & DRBG_FLAG_TEST)
 492                 return 1;
 493         /* Check block is valid: should never happen */
 494         if (dctx->lb_valid == 0)
 495                 {
 496                 FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_INTERNAL_ERROR);
 497                 fips_set_selftest_fail();
 498                 return 0;
 499                 }
 500         if (drbg_stick)
 501                 memcpy(dctx->lb, out, dctx->blocklength);
 502         /* Check against last block: fail if match */
 503         if (!memcmp(dctx->lb, out, dctx->blocklength))
 504                 {
 505                 FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_DRBG_STUCK);
 506                 fips_set_selftest_fail();
 507                 return 0;
 508                 }
 509         /* Save last block for next comparison */
 510         memcpy(dctx->lb, out, dctx->blocklength);
 511         return 1;
 512         }