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->d, sizeof(dctx->d));
 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 = 0, noncelen = 0;
 125         unsigned char *nonce = NULL, *entropy = NULL;
 126
 127 #if 0
 128         /* Put here so error script picks them up */
 129         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE,
 130                                 FIPS_R_PERSONALISATION_STRING_TOO_LONG);
 131         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_IN_ERROR_STATE);
 132         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ALREADY_INSTANTIATED);
 133         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_ENTROPY);
 134         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_NONCE);
 135         FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_INSTANTIATE_ERROR);
 136 #endif
 137
 138         int r = 0;
 139
 140         if (perslen > dctx->max_pers)
 141                 {
 142                 r = FIPS_R_PERSONALISATION_STRING_TOO_LONG;
 143                 goto end;
 144                 }
 145
 146         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 147                 {
 148                 if (dctx->status == DRBG_STATUS_ERROR)
 149                         r = FIPS_R_IN_ERROR_STATE;
 150                 else
 151                         r = FIPS_R_ALREADY_INSTANTIATED;
 152                 goto end;
 153                 }
 154
 155         dctx->status = DRBG_STATUS_ERROR;
 156
 157         entlen = dctx->get_entropy(dctx, &entropy, dctx->strength,
 158                                 dctx->min_entropy, dctx->max_entropy);
 159
 160         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 161                 {
 162                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 163                 goto end;
 164                 }
 165
 166         if (dctx->max_nonce > 0)
 167                 {
 168                 noncelen = dctx->get_nonce(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
 180         if (!dctx->instantiate(dctx,
 181                                 entropy, entlen,
 182                                 nonce, noncelen,
 183                                 pers, perslen))
 184                 {
 185                 r = FIPS_R_ERROR_INSTANTIATING_DRBG;
 186                 goto end;
 187                 }
 188
 189
 190         dctx->status = DRBG_STATUS_READY;
 191         dctx->reseed_counter = 1;
 192
 193         end:
 194
 195         if (entropy && dctx->cleanup_entropy)
 196                 dctx->cleanup_entropy(dctx, entropy, entlen);
 197
 198         if (nonce && dctx->cleanup_nonce)
 199                 dctx->cleanup_nonce(dctx, nonce, noncelen);
 200
 201         if (dctx->status == DRBG_STATUS_READY)
 202                 return 1;
 203
 204         if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 205                 FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, r);
 206
 207         return 0;
 208
 209         }
 210
 211 int FIPS_drbg_reseed(DRBG_CTX *dctx,
 212                         const unsigned char *adin, size_t adinlen)
 213         {
 214         unsigned char *entropy = NULL;
 215         size_t entlen;
 216         int r = 0;
 217
 218 #if 0
 219         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_NOT_INSTANTIATED);
 220         FIPSerr(FIPS_F_FIPS_DRBG_RESEED, FIPS_R_ADDITIONAL_INPUT_TOO_LONG);
 221 #endif
 222         if (dctx->status != DRBG_STATUS_READY
 223                 && dctx->status != DRBG_STATUS_RESEED)
 224                 {
 225                 if (dctx->status == DRBG_STATUS_ERROR)
 226                         r = FIPS_R_IN_ERROR_STATE;
 227                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 228                         r = FIPS_R_NOT_INSTANTIATED;
 229                 goto end;
 230                 }
 231
 232         if (!adin)
 233                 adinlen = 0;
 234         else if (adinlen > dctx->max_adin)
 235                 {
 236                 r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
 237                 goto end;
 238                 }
 239
 240         dctx->status = DRBG_STATUS_ERROR;
 241
 242         entlen = dctx->get_entropy(dctx, &entropy, dctx->strength,
 243                                 dctx->min_entropy, dctx->max_entropy);
 244
 245         if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 246                 {
 247                 r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 248                 goto end;
 249                 }
 250
 251         if (!dctx->reseed(dctx, entropy, entlen, adin, adinlen))
 252                 goto end;
 253
 254         dctx->status = DRBG_STATUS_READY;
 255         dctx->reseed_counter = 1;
 256         end:
 257
 258         if (entropy && dctx->cleanup_entropy)
 259                 dctx->cleanup_entropy(dctx, entropy, entlen);
 260
 261         if (dctx->status == DRBG_STATUS_READY)
 262                 return 1;
 263
 264         if (r && !(dctx->flags & DRBG_FLAG_NOERR))
 265                 FIPSerr(FIPS_F_FIPS_DRBG_RESEED, r);
 266
 267         return 0;
 268         }
 269
 270
 271 int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 272                         int strength, int prediction_resistance,
 273                         const unsigned char *adin, size_t adinlen)
 274         {
 275         int r = 0;
 276
 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 (outlen > dctx->max_request)
 288                 {
 289                 r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
 290                 return 0;
 291                 }
 292
 293         if (strength > dctx->strength)
 294                 {
 295                 r = FIPS_R_INSUFFICIENT_SECURITY_STRENGTH;
 296                 goto end;
 297                 }
 298
 299         if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)
 300                 {
 301                 if (!FIPS_drbg_reseed(dctx, adin, adinlen))
 302                         {
 303                         r = FIPS_R_RESEED_ERROR;
 304                         goto end;
 305                         }
 306                 adin = NULL;
 307                 adinlen = 0;
 308                 }
 309
 310         if (!dctx->generate(dctx, out, outlen, adin, adinlen))
 311                 {
 312                 r = FIPS_R_GENERATE_ERROR;
 313                 dctx->status = DRBG_STATUS_ERROR;
 314                 goto end;
 315                 }
 316         if (dctx->reseed_counter >= dctx->reseed_interval)
 317                 dctx->status = DRBG_STATUS_RESEED;
 318         else
 319                 dctx->reseed_counter++;
 320
 321         end:
 322         if (r)
 323                 {
 324                 if (!(dctx->flags & DRBG_FLAG_NOERR))
 325                         FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
 326                 return 0;
 327                 }
 328
 329         return 1;
 330         }
 331
 332 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
 333         {
 334         int rv;
 335         if (!dctx->uninstantiate)
 336                 rv = 1;
 337         else
 338                 rv = dctx->uninstantiate(dctx);
 339         /* Although we'd like to cleanse here we can't because we have to
 340          * test the uninstantiate really zeroes the data.
 341          */
 342         memset(&dctx->d, 0, sizeof(dctx->d));
 343         dctx->status = DRBG_STATUS_UNINITIALISED;
 344         /* If method has problems uninstantiating, return error */
 345         return rv;
 346         }
 347
 348 int FIPS_drbg_set_callbacks(DRBG_CTX *dctx,
 349         size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char **pout,
 350                                 int entropy, size_t min_len, size_t max_len),
 351         void (*cleanup_entropy)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 352         size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char **pout,
 353                                 int entropy, size_t min_len, size_t max_len),
 354         void (*cleanup_nonce)(DRBG_CTX *ctx, unsigned char *out, size_t olen))
 355         {
 356         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 357                 return 0;
 358         dctx->get_entropy = get_entropy;
 359         dctx->cleanup_entropy = cleanup_entropy;
 360         dctx->get_nonce = get_nonce;
 361         dctx->cleanup_nonce = cleanup_nonce;
 362         return 1;
 363         }
 364
 365 int FIPS_drbg_set_rand_callbacks(DRBG_CTX *dctx,
 366         size_t (*get_adin)(DRBG_CTX *ctx, unsigned char **pout),
 367         void (*cleanup_adin)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 368         int (*rand_seed_cb)(DRBG_CTX *ctx, const void *buf, int num),
 369         int (*rand_add_cb)(DRBG_CTX *ctx,
 370                                 const void *buf, int num, double entropy))
 371         {
 372         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 373                 return 0;
 374         dctx->get_adin = get_adin;
 375         dctx->cleanup_adin = cleanup_adin;
 376         dctx->rand_seed_cb = rand_seed_cb;
 377         dctx->rand_add_cb = rand_add_cb;
 378         return 1;
 379         }
 380
 381 void *FIPS_drbg_get_app_data(DRBG_CTX *dctx)
 382         {
 383         return dctx->app_data;
 384         }
 385
 386 void FIPS_drbg_set_app_data(DRBG_CTX *dctx, void *app_data)
 387         {
 388         dctx->app_data = app_data;
 389         }
 390
 391 size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx)
 392         {
 393         return dctx->blocklength;
 394         }
 395
 396 int FIPS_drbg_get_strength(DRBG_CTX *dctx)
 397         {
 398         return dctx->strength;
 399         }
 400
 401 static int drbg_stick = 0;
 402
 403 void FIPS_drbg_stick(void)
 404         {
 405         drbg_stick = 1;
 406         }
 407
 408 /* Continuous DRBG utility function */
 409 int drbg_cprng_test(DRBG_CTX *dctx, const unsigned char *out)
 410         {
 411         /* No CPRNG in test mode */
 412         if (dctx->flags & DRBG_FLAG_TEST)
 413                 return 1;
 414         /* Check block is valid: should never happen */
 415         if (dctx->lb_valid == 0)
 416                 {
 417                 FIPSerr(FIPS_F_DRBG_CPRNG_TEST, FIPS_R_INTERNAL_ERROR);
 418                 fips_set_selftest_fail();
 419                 return 0;
 420                 }
 421         if (drbg_stick)
 422                 memcpy(dctx->lb, out, dctx->blocklength);
 423         /* Check against last block: fail if match */
 424         if (!memcmp(dctx->lb, out, dctx->blocklength))
 425                 {
 426                 FIPSerr(FIPS_F_DRBG_CPRNG_TEST, FIPS_R_DRBG_STUCK);
 427                 fips_set_selftest_fail();
 428                 return 0;
 429                 }
 430         /* Save last block for next comparison */
 431         memcpy(dctx->lb, out, dctx->blocklength);
 432         return 1;
 433         }