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