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         rv = fips_drbg_hash_init(dctx);
  75
  76         if (rv == -2)
  77                 rv = fips_drbg_ctr_init(dctx);
  78
  79         if (rv <= 0)
  80                 {
  81                 if (rv == -2)
  82                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_UNSUPPORTED_DRBG_TYPE);
  83                 else
  84                         FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_ERROR_INITIALISING_DRBG);
  85                 }
  86
  87         return rv;
  88         }
  89
  90 DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
  91         {
  92         int rv;
  93         DRBG_CTX *dctx;
  94         dctx = OPENSSL_malloc(sizeof(DRBG_CTX));
  95         if (!dctx)
  96                 {
  97                 FIPSerr(FIPS_F_FIPS_DRBG_NEW, ERR_R_MALLOC_FAILURE);
  98                 return NULL;
  99                 }
 100         if (type == 0)
 101                 return dctx;
 102         rv = FIPS_drbg_init(dctx, type, flags);
 103
 104         if (FIPS_drbg_init(dctx, type, flags) <= 0)
 105                 {
 106                 OPENSSL_free(dctx);
 107                 return NULL;
 108                 }
 109
 110         return dctx;
 111         }
 112
 113 void FIPS_drbg_free(DRBG_CTX *dctx)
 114         {
 115         if (dctx->uninstantiate)
 116                 dctx->uninstantiate(dctx);
 117         OPENSSL_cleanse(dctx, sizeof(DRBG_CTX));
 118         OPENSSL_free(dctx);
 119         }
 120
 121 int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 122                                 const unsigned char *pers, size_t perslen)
 123         {
 124         size_t entlen, noncelen;
 125
 126 #if 0
 127         /* Put here so error script picks them up */
 128         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE,
 129                                 FIPS_R_PERSONALISATION_STRING_TOO_LONG);
 130         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_IN_ERROR_STATE);
 131         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ALREADY_INSTANTIATED);
 132         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_ENTROPY);
 133         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_NONCE);
 134         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_INSTANTIATE_ERROR);
 135 #endif
 136
 137         int r = 0;
 138
 139         if (perslen > dctx->max_pers)
 140                 {
 141                 r = FIPS_R_PERSONALISATION_STRING_TOO_LONG;
 142                 goto end;
 143                 }
 144
 145         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 146                 {
 147                 if (dctx->status == DRBG_STATUS_ERROR)
 148                         r = FIPS_R_IN_ERROR_STATE;
 149                 else
 150                         r = FIPS_R_ALREADY_INSTANTIATED;
 151                 goto end;
 152                 }
 153
 154         dctx->status = DRBG_STATUS_ERROR;
 155
 156         entlen = dctx->get_entropy(dctx, dctx->entropy, dctx->strength,
 157                                 dctx->min_entropy, dctx->max_entropy);
 158
 159         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 160                 {
 161                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 162                 goto end;
 163                 }
 164
 165         if (dctx->max_nonce > 0)
 166                 {
 167
 168                 noncelen = dctx->get_nonce(dctx, dctx->nonce,
 169                                         dctx->strength / 2,
 170                                         dctx->min_nonce, dctx->max_nonce);
 171
 172                 if (noncelen < dctx->min_nonce || noncelen > dctx->max_nonce)
 173                         {
 174                         r = FIPS_R_ERROR_RETRIEVING_NONCE;
 175                         goto end;
 176                         }
 177
 178                 }
 179         else
 180                 noncelen = 0;
 181
 182         if (!dctx->instantiate(dctx,
 183                                 dctx->entropy, entlen,
 184                                 dctx->nonce, noncelen,
 185                                 pers, perslen))
 186                 {
 187                 r = FIPS_R_ERROR_INSTANTIATING_DRBG;
 188                 goto end;
 189                 }
 190
 191
 192         dctx->status = DRBG_STATUS_READY;
 193         dctx->reseed_counter = 1;
 194
 195         end:
 196
 197         OPENSSL_cleanse(dctx->entropy, sizeof(dctx->entropy));
 198         OPENSSL_cleanse(dctx->nonce, sizeof(dctx->nonce));
 199
 200         if (dctx->status == DRBG_STATUS_READY)
 201                 return 1;
 202
 203         if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 204                 FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, r);
 205
 206         return 0;
 207
 208         }
 209
 210 int FIPS_drbg_reseed(DRBG_CTX *dctx,
 211                         const unsigned char *adin, size_t adinlen)
 212         {
 213         size_t entlen;
 214         int r = 0;
 215
 216 #if 0
 217         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_NOT_INSTANTIATED);
 218         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_ADDITIONAL_INPUT_TOO_LONG);
 219 #endif
 220         if (dctx->status != DRBG_STATUS_READY
 221                 && dctx->status != DRBG_STATUS_RESEED)
 222                 {
 223                 if (dctx->status == DRBG_STATUS_ERROR)
 224                         r = FIPS_R_IN_ERROR_STATE;
 225                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 226                         r = FIPS_R_NOT_INSTANTIATED;
 227                 goto end;
 228                 }
 229
 230         if (!adin)
 231                 adinlen = 0;
 232         else if (adinlen > dctx->max_adin)
 233                 {
 234                 r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
 235                 goto end;
 236                 }
 237
 238         dctx->status = DRBG_STATUS_ERROR;
 239
 240         entlen = dctx->get_entropy(dctx, dctx->entropy, dctx->strength,
 241                                 dctx->min_entropy, dctx->max_entropy);
 242
 243         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 244                 {
 245                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 246                 goto end;
 247                 }
 248
 249         if (!dctx->reseed(dctx, dctx->entropy, entlen, adin, adinlen))
 250                 goto end;
 251
 252         dctx->status = DRBG_STATUS_READY;
 253         dctx->reseed_counter = 1;
 254         end:
 255         OPENSSL_cleanse(dctx->entropy, sizeof(dctx->entropy));
 256
 257         if (dctx->status == DRBG_STATUS_READY)
 258                 return 1;
 259
 260         if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 261                 FIPSerr(FIPS_F_FIPS_DRBG_RESEED, r);
 262
 263         return 0;
 264         }
 265
 266
 267 static int fips_drbg_generate_internal(DRBG_CTX *dctx,
 268                         unsigned char *out, size_t outlen,
 269                         int strength, int prediction_resistance,
 270                         const unsigned char *adin, size_t adinlen)
 271         {
 272         int r = 0;
 273         if (outlen > dctx->max_request)
 274                 {
 275                 r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
 276                 return 0;
 277                 }
 278
 279         if (strength > dctx->strength)
 280                 {
 281                 r = FIPS_R_INSUFFICIENT_SECURITY_STRENGTH;
 282                 goto end;
 283                 }
 284
 285         if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)
 286                 {
 287                 if (!FIPS_drbg_reseed(dctx, adin, adinlen))
 288                         {
 289                         r = FIPS_R_RESEED_ERROR;
 290                         goto end;
 291                         }
 292                 adin = NULL;
 293                 adinlen = 0;
 294                 }
 295         if (dctx->status != DRBG_STATUS_READY)
 296                 {
 297                 if (dctx->status == DRBG_STATUS_ERROR)
 298                         r = FIPS_R_IN_ERROR_STATE;
 299                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 300                         r = FIPS_R_NOT_INSTANTIATED;
 301                 goto end;
 302                 }
 303         if (!dctx->generate(dctx, out, outlen, adin, adinlen))
 304                 {
 305                 r = FIPS_R_GENERATE_ERROR;
 306                 dctx->status = DRBG_STATUS_ERROR;
 307                 goto end;
 308                 }
 309         if (dctx->reseed_counter >= dctx->reseed_interval)
 310                 dctx->status = DRBG_STATUS_RESEED;
 311         else
 312                 dctx->reseed_counter++;
 313
 314         end:
 315         if (r)
 316                 {
 317                 if (!(dctx->flags & DRBG_FLAG_NOERR))
 318                         FIPSerr(FIPS_F_FIPS_DRBG_GENERATE_INTERNAL, r);
 319                 return 0;
 320                 }
 321
 322         return 1;
 323         }
 324
 325 /* external generate function: incorporates continuous RNG test if not
 326  * in test mode.
 327  */
 328
 329 int FIPS_drbg_generate(DRBG_CTX *dctx,
 330                         unsigned char *out, size_t outlen,
 331                         int strength, int prediction_resistance,
 332                         const unsigned char *adin, size_t adinlen)
 333         {
 334         unsigned char tmp[16], *pout;
 335         size_t poutlen;
 336         /* If test mode don't run continuous RNG test */
 337         if (dctx->flags & DRBG_FLAG_TEST)
 338                 {
 339                 return fips_drbg_generate_internal(dctx, out, outlen,
 340                                                         strength,
 341                                                         prediction_resistance,
 342                                                         adin, adinlen);
 343                 }
 344         /* If this is the first call generate block and save buffer */
 345         if (!dctx->lb_valid)
 346                 {
 347                 if (!fips_drbg_generate_internal(dctx, dctx->lb, 16,
 348                                                 strength, prediction_resistance,
 349                                                 adin, adinlen))
 350                         return 0;
 351                 dctx->lb_valid = 1;
 352                 }
 353
 354         /* If request less that 16 bytes request 16 in temp buffer */
 355
 356         if (outlen < 16)
 357                 {
 358                 pout = tmp;
 359                 poutlen = 16;
 360                 }
 361         else
 362                 {
 363                 pout = out;
 364                 poutlen = outlen;
 365                 }
 366
 367         /* Generate data */
 368         if (!fips_drbg_generate_internal(dctx, pout, poutlen,
 369                                                 strength, prediction_resistance,
 370                                                 adin, adinlen))
 371                         return 0;
 372         /* Compare to last block for continuous PRNG test */
 373         if (!memcmp(pout, dctx->lb, 16))
 374                 {
 375                 FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, FIPS_R_DRBG_STUCK);
 376                 return 0;
 377                 }
 378         /* Update last block */
 379         memcpy(dctx->lb, pout, 16);
 380         /* Copy to output buffer if needed */
 381         if (outlen < 16)
 382                 memcpy(out, pout, outlen);
 383
 384         return 1;
 385
 386         }
 387
 388 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
 389         {
 390         int rv;
 391         if (!dctx->uninstantiate)
 392                 rv = 1;
 393         else
 394                 rv = dctx->uninstantiate(dctx);
 395         /* Although we'd like to cleanse here we can't because we have to
 396          * test the uninstantiate really zeroes the data.
 397          */
 398         memset(dctx, 0, sizeof(DRBG_CTX));
 399         /* If method has problems uninstantiating, return error */
 400         return rv;
 401         }
 402
 403 int FIPS_drbg_set_test_mode(DRBG_CTX *dctx,
 404         size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char *out,
 405                                 int entropy, size_t min_len, size_t max_len),
 406         size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char *out,
 407                                 int entropy, size_t min_len, size_t max_len))
 408         {
 409         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 410                 return 0;
 411         dctx->flags |= DRBG_FLAG_TEST;
 412         dctx->get_entropy = get_entropy;
 413         dctx->get_nonce = get_nonce;
 414         return 1;
 415         }
 416
 417 void *FIPS_drbg_get_app_data(DRBG_CTX *dctx)
 418         {
 419         return dctx->app_data;
 420         }
 421
 422 void FIPS_drbg_set_app_data(DRBG_CTX *dctx, void *app_data)
 423         {
 424         dctx->app_data = app_data;
 425         }
 426
 427 size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx)
 428         {
 429         return dctx->blocklength;
 430         }
 431
 432 int FIPS_drbg_get_strength(DRBG_CTX *dctx)
 433         {
 434         return dctx->strength;
 435         }