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->flags = flags;
  70         dctx->type = type;
  71
  72         dctx->entropy_blocklen = 0;
  73         dctx->health_check_cnt = 0;
  74         dctx->health_check_interval = DRBG_HEALTH_INTERVAL;
  75
  76         rv = fips_drbg_hash_init(dctx);
  77
  78         if (rv == -2)
  79                 rv = fips_drbg_ctr_init(dctx);
  80         if (rv == -2)
  81                 rv = fips_drbg_hmac_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                         dctx->status = DRBG_STATUS_ERROR;
 100                         return 0;
 101                         }
 102                 }
 103
 104         return rv;
 105         }
 106
 107 DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
 108         {
 109         DRBG_CTX *dctx;
 110         dctx = OPENSSL_malloc(sizeof(DRBG_CTX));
 111         if (!dctx)
 112                 {
 113                 FIPSerr(FIPS_F_FIPS_DRBG_NEW, ERR_R_MALLOC_FAILURE);
 114                 return NULL;
 115                 }
 116         if (type == 0)
 117                 return dctx;
 118
 119         if (FIPS_drbg_init(dctx, type, flags) <= 0)
 120                 {
 121                 OPENSSL_free(dctx);
 122                 return NULL;
 123                 }
 124
 125         return dctx;
 126         }
 127
 128 void FIPS_drbg_free(DRBG_CTX *dctx)
 129         {
 130         if (dctx->uninstantiate)
 131                 dctx->uninstantiate(dctx);
 132         OPENSSL_cleanse(&dctx->d, sizeof(dctx->d));
 133         OPENSSL_free(dctx);
 134         }
 135
 136 static size_t fips_get_entropy(DRBG_CTX *dctx, unsigned char **pout,
 137                                 int entropy, size_t min_len, size_t max_len)
 138         {
 139         unsigned char *tout, *p;
 140         size_t bl = dctx->entropy_blocklen, rv;
 141         if (dctx->flags & DRBG_FLAG_TEST || !bl)
 142                 return dctx->get_entropy(dctx, pout, entropy, min_len, max_len);
 143         rv = dctx->get_entropy(dctx, &tout, entropy + bl,
 144                                 min_len + bl, max_len + bl);
 145         *pout = tout + bl;
 146         if (rv < (min_len + bl) || (rv % bl))
 147                 return 0;
 148         /* Compare consecutive blocks for continuous PRNG test */
 149         for (p = tout; p < tout + rv - bl; p += bl)
 150                 {
 151                 if (!memcmp(p, p + bl, bl))
 152                         {
 153                         FIPSerr(FIPS_F_FIPS_GET_ENTROPY, FIPS_R_ENTROPY_SOURCE_STUCK);
 154                         return 0;
 155                         }
 156                 }
 157         rv -= bl;
 158         if (rv > max_len)
 159                 return max_len;
 160         return rv;
 161         }
 162
 163 static void fips_cleanup_entropy(DRBG_CTX *dctx,
 164                                         unsigned char *out, size_t olen)
 165         {
 166         size_t bl;
 167         if (dctx->flags & DRBG_FLAG_TEST)
 168                 bl = 0;
 169         else
 170                 bl = dctx->entropy_blocklen;
 171         /* Call cleanup with original arguments */
 172         dctx->cleanup_entropy(dctx, out - bl, olen + bl);
 173         }
 174
 175
 176 int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 177                                 const unsigned char *pers, size_t perslen)
 178         {
 179         size_t entlen = 0, noncelen = 0;
 180         unsigned char *nonce = NULL, *entropy = NULL;
 181
 182 #if 0
 183         /* Put here so error script picks them up */
 184         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE,
 185                                 FIPS_R_PERSONALISATION_STRING_TOO_LONG);
 186         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_IN_ERROR_STATE);
 187         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ALREADY_INSTANTIATED);
 188         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_ENTROPY);
 189         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_NONCE);
 190         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_INSTANTIATE_ERROR);
 191 #endif
 192
 193         int r = 0;
 194
 195         if (perslen > dctx->max_pers)
 196                 {
 197                 r = FIPS_R_PERSONALISATION_STRING_TOO_LONG;
 198                 goto end;
 199                 }
 200
 201         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 202                 {
 203                 if (dctx->status == DRBG_STATUS_ERROR)
 204                         r = FIPS_R_IN_ERROR_STATE;
 205                 else
 206                         r = FIPS_R_ALREADY_INSTANTIATED;
 207                 goto end;
 208                 }
 209
 210         dctx->status = DRBG_STATUS_ERROR;
 211
 212         entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
 213                                 dctx->min_entropy, dctx->max_entropy);
 214
 215         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 216                 {
 217                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 218                 goto end;
 219                 }
 220
 221         if (dctx->max_nonce > 0)
 222                 {
 223                 noncelen = dctx->get_nonce(dctx, &nonce,
 224                                         dctx->strength / 2,
 225                                         dctx->min_nonce, dctx->max_nonce);
 226
 227                 if (noncelen < dctx->min_nonce || noncelen > dctx->max_nonce)
 228                         {
 229                         r = FIPS_R_ERROR_RETRIEVING_NONCE;
 230                         goto end;
 231                         }
 232
 233                 }
 234
 235         if (!dctx->instantiate(dctx,
 236                                 entropy, entlen,
 237                                 nonce, noncelen,
 238                                 pers, perslen))
 239                 {
 240                 r = FIPS_R_ERROR_INSTANTIATING_DRBG;
 241                 goto end;
 242                 }
 243
 244
 245         dctx->status = DRBG_STATUS_READY;
 246         dctx->reseed_counter = 1;
 247
 248         end:
 249
 250         if (entropy && dctx->cleanup_entropy)
 251                 fips_cleanup_entropy(dctx, entropy, entlen);
 252
 253         if (nonce && dctx->cleanup_nonce)
 254                 dctx->cleanup_nonce(dctx, nonce, noncelen);
 255
 256         if (dctx->status == DRBG_STATUS_READY)
 257                 return 1;
 258
 259         if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 260                 FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, r);
 261
 262         return 0;
 263
 264         }
 265
 266 int FIPS_drbg_reseed(DRBG_CTX *dctx,
 267                         const unsigned char *adin, size_t adinlen)
 268         {
 269         unsigned char *entropy = NULL;
 270         size_t entlen;
 271         int r = 0;
 272
 273 #if 0
 274         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_NOT_INSTANTIATED);
 275         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_ADDITIONAL_INPUT_TOO_LONG);
 276 #endif
 277         if (dctx->status != DRBG_STATUS_READY
 278                 && dctx->status != DRBG_STATUS_RESEED)
 279                 {
 280                 if (dctx->status == DRBG_STATUS_ERROR)
 281                         r = FIPS_R_IN_ERROR_STATE;
 282                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 283                         r = FIPS_R_NOT_INSTANTIATED;
 284                 goto end;
 285                 }
 286
 287         if (!adin)
 288                 adinlen = 0;
 289         else if (adinlen > dctx->max_adin)
 290                 {
 291                 r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
 292                 goto end;
 293                 }
 294
 295         dctx->status = DRBG_STATUS_ERROR;
 296
 297         entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
 298                                 dctx->min_entropy, dctx->max_entropy);
 299
 300         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 301                 {
 302                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 303                 goto end;
 304                 }
 305
 306         if (!dctx->reseed(dctx, entropy, entlen, adin, adinlen))
 307                 goto end;
 308
 309         dctx->status = DRBG_STATUS_READY;
 310         dctx->reseed_counter = 1;
 311         end:
 312
 313         if (entropy && dctx->cleanup_entropy)
 314                 fips_cleanup_entropy(dctx, entropy, entlen);
 315
 316         if (dctx->status == DRBG_STATUS_READY)
 317                 return 1;
 318
 319         if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 320                 FIPSerr(FIPS_F_FIPS_DRBG_RESEED, r);
 321
 322         return 0;
 323         }
 324
 325 static int fips_drbg_check(DRBG_CTX *dctx)
 326         {
 327         if (dctx->flags & DRBG_FLAG_TEST)
 328                 return 1;
 329         dctx->health_check_cnt++;
 330         if (dctx->health_check_cnt >= dctx->health_check_interval)
 331                 {
 332                 DRBG_CTX tctx;
 333                 if (!fips_drbg_kat(&tctx, dctx->type,
 334                                                 dctx->flags | DRBG_FLAG_TEST))
 335                         {
 336                         FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);
 337                         dctx->status = DRBG_STATUS_ERROR;
 338                         return 0;
 339                         }
 340                 dctx->health_check_cnt = 0;
 341                 }
 342         return 1;
 343         }
 344
 345 int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 346                         int strength, int prediction_resistance,
 347                         const unsigned char *adin, size_t adinlen)
 348         {
 349         int r = 0;
 350
 351         if (!fips_drbg_check(dctx))
 352                 return 0;
 353
 354         if (dctx->status != DRBG_STATUS_READY
 355                 && dctx->status != DRBG_STATUS_RESEED)
 356                 {
 357                 if (dctx->status == DRBG_STATUS_ERROR)
 358                         r = FIPS_R_IN_ERROR_STATE;
 359                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 360                         r = FIPS_R_NOT_INSTANTIATED;
 361                 goto end;
 362                 }
 363
 364         if (outlen > dctx->max_request)
 365                 {
 366                 r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
 367                 return 0;
 368                 }
 369
 370         if (strength > dctx->strength)
 371                 {
 372                 r = FIPS_R_INSUFFICIENT_SECURITY_STRENGTH;
 373                 goto end;
 374                 }
 375
 376         if (dctx->reseed_counter >= dctx->reseed_interval)
 377                 dctx->status = DRBG_STATUS_RESEED;
 378
 379         if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)
 380                 {
 381                 if (!FIPS_drbg_reseed(dctx, adin, adinlen))
 382                         {
 383                         r = FIPS_R_RESEED_ERROR;
 384                         goto end;
 385                         }
 386                 adin = NULL;
 387                 adinlen = 0;
 388                 }
 389
 390         if (!dctx->generate(dctx, out, outlen, adin, adinlen))
 391                 {
 392                 r = FIPS_R_GENERATE_ERROR;
 393                 dctx->status = DRBG_STATUS_ERROR;
 394                 goto end;
 395                 }
 396         if (dctx->reseed_counter >= dctx->reseed_interval)
 397                 dctx->status = DRBG_STATUS_RESEED;
 398         else
 399                 dctx->reseed_counter++;
 400
 401         end:
 402         if (r)
 403                 {
 404                 if (!(dctx->flags & DRBG_FLAG_NOERR))
 405                         FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
 406                 return 0;
 407                 }
 408
 409         return 1;
 410         }
 411
 412 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
 413         {
 414         int rv;
 415         if (!dctx->uninstantiate)
 416                 rv = 1;
 417         else
 418                 rv = dctx->uninstantiate(dctx);
 419         /* Although we'd like to cleanse here we can't because we have to
 420          * test the uninstantiate really zeroes the data.
 421          */
 422         memset(&dctx->d, 0, sizeof(dctx->d));
 423         dctx->status = DRBG_STATUS_UNINITIALISED;
 424         /* If method has problems uninstantiating, return error */
 425         return rv;
 426         }
 427
 428 int FIPS_drbg_set_callbacks(DRBG_CTX *dctx,
 429         size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char **pout,
 430                                 int entropy, size_t min_len, size_t max_len),
 431         void (*cleanup_entropy)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 432         size_t entropy_blocklen,
 433         size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char **pout,
 434                                 int entropy, size_t min_len, size_t max_len),
 435         void (*cleanup_nonce)(DRBG_CTX *ctx, unsigned char *out, size_t olen))
 436         {
 437         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 438                 return 0;
 439         dctx->entropy_blocklen = entropy_blocklen;
 440         dctx->get_entropy = get_entropy;
 441         dctx->cleanup_entropy = cleanup_entropy;
 442         dctx->get_nonce = get_nonce;
 443         dctx->cleanup_nonce = cleanup_nonce;
 444         return 1;
 445         }
 446
 447 int FIPS_drbg_set_rand_callbacks(DRBG_CTX *dctx,
 448         size_t (*get_adin)(DRBG_CTX *ctx, unsigned char **pout),
 449         void (*cleanup_adin)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 450         int (*rand_seed_cb)(DRBG_CTX *ctx, const void *buf, int num),
 451         int (*rand_add_cb)(DRBG_CTX *ctx,
 452                                 const void *buf, int num, double entropy))
 453         {
 454         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 455                 return 0;
 456         dctx->get_adin = get_adin;
 457         dctx->cleanup_adin = cleanup_adin;
 458         dctx->rand_seed_cb = rand_seed_cb;
 459         dctx->rand_add_cb = rand_add_cb;
 460         return 1;
 461         }
 462
 463 void *FIPS_drbg_get_app_data(DRBG_CTX *dctx)
 464         {
 465         return dctx->app_data;
 466         }
 467
 468 void FIPS_drbg_set_app_data(DRBG_CTX *dctx, void *app_data)
 469         {
 470         dctx->app_data = app_data;
 471         }
 472
 473 size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx)
 474         {
 475         return dctx->blocklength;
 476         }
 477
 478 int FIPS_drbg_get_strength(DRBG_CTX *dctx)
 479         {
 480         return dctx->strength;
 481         }
 482
 483 void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval)
 484         {
 485         dctx->health_check_interval = interval;
 486         }
 487
 488 static int drbg_stick = 0;
 489
 490 void FIPS_drbg_stick(void)
 491         {
 492         drbg_stick = 1;
 493         }
 494
 495 /* Continuous DRBG utility function */
 496 int fips_drbg_cprng_test(DRBG_CTX *dctx, const unsigned char *out)
 497         {
 498         /* No CPRNG in test mode */
 499         if (dctx->flags & DRBG_FLAG_TEST)
 500                 return 1;
 501         /* Check block is valid: should never happen */
 502         if (dctx->lb_valid == 0)
 503                 {
 504                 FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_INTERNAL_ERROR);
 505                 fips_set_selftest_fail();
 506                 return 0;
 507                 }
 508         if (drbg_stick)
 509                 memcpy(dctx->lb, out, dctx->blocklength);
 510         /* Check against last block: fail if match */
 511         if (!memcmp(dctx->lb, out, dctx->blocklength))
 512                 {
 513                 FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_DRBG_STUCK);
 514                 fips_set_selftest_fail();
 515                 return 0;
 516                 }
 517         /* Save last block for next comparison */
 518         memcpy(dctx->lb, out, dctx->blocklength);
 519         return 1;
 520         }