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