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 = 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 static int fips_drbg_generate_internal(DRBG_CTX *dctx,
 272                         unsigned char *out, size_t outlen,
 273                         int strength, int prediction_resistance,
 274                         const unsigned char *adin, size_t adinlen)
 275         {
 276         int r = 0;
 277
 278         if (dctx->status != DRBG_STATUS_READY
 279                 && dctx->status != DRBG_STATUS_RESEED)
 280                 {
 281                 if (dctx->status == DRBG_STATUS_ERROR)
 282                         r = FIPS_R_IN_ERROR_STATE;
 283                 else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 284                         r = FIPS_R_NOT_INSTANTIATED;
 285                 goto end;
 286                 }
 287
 288         if (outlen > dctx->max_request)
 289                 {
 290                 r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
 291                 return 0;
 292                 }
 293
 294         if (strength > dctx->strength)
 295                 {
 296                 r = FIPS_R_INSUFFICIENT_SECURITY_STRENGTH;
 297                 goto end;
 298                 }
 299
 300         if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)
 301                 {
 302                 if (!FIPS_drbg_reseed(dctx, adin, adinlen))
 303                         {
 304                         r = FIPS_R_RESEED_ERROR;
 305                         goto end;
 306                         }
 307                 adin = NULL;
 308                 adinlen = 0;
 309                 }
 310
 311         if (!dctx->generate(dctx, out, outlen, adin, adinlen))
 312                 {
 313                 r = FIPS_R_GENERATE_ERROR;
 314                 dctx->status = DRBG_STATUS_ERROR;
 315                 goto end;
 316                 }
 317         if (dctx->reseed_counter >= dctx->reseed_interval)
 318                 dctx->status = DRBG_STATUS_RESEED;
 319         else
 320                 dctx->reseed_counter++;
 321
 322         end:
 323         if (r)
 324                 {
 325                 if (!(dctx->flags & DRBG_FLAG_NOERR))
 326                         FIPSerr(FIPS_F_FIPS_DRBG_GENERATE_INTERNAL, r);
 327                 return 0;
 328                 }
 329
 330         return 1;
 331         }
 332
 333 /* external generate function: incorporates continuous RNG test if not
 334  * in test mode.
 335  */
 336
 337 int FIPS_drbg_generate(DRBG_CTX *dctx,
 338                         unsigned char *out, size_t outlen,
 339                         int strength, int prediction_resistance,
 340                         const unsigned char *adin, size_t adinlen)
 341         {
 342         unsigned char tmp[16], *pout;
 343         size_t poutlen;
 344         /* If test mode don't run continuous RNG test */
 345         if (dctx->flags & DRBG_FLAG_TEST)
 346                 {
 347                 return fips_drbg_generate_internal(dctx, out, outlen,
 348                                                         strength,
 349                                                         prediction_resistance,
 350                                                         adin, adinlen);
 351                 }
 352         /* If this is the first call generate block and save buffer */
 353         if (!dctx->lb_valid)
 354                 {
 355                 if (!fips_drbg_generate_internal(dctx, dctx->lb, 16,
 356                                                 strength, prediction_resistance,
 357                                                 adin, adinlen))
 358                         return 0;
 359                 dctx->lb_valid = 1;
 360                 }
 361
 362         /* If request less that 16 bytes request 16 in temp buffer */
 363
 364         if (outlen < 16)
 365                 {
 366                 pout = tmp;
 367                 poutlen = 16;
 368                 }
 369         else
 370                 {
 371                 pout = out;
 372                 poutlen = outlen;
 373                 }
 374
 375         /* Generate data */
 376         if (!fips_drbg_generate_internal(dctx, pout, poutlen,
 377                                                 strength, prediction_resistance,
 378                                                 adin, adinlen))
 379                         return 0;
 380         /* Compare to last block for continuous PRNG test */
 381         if (!memcmp(pout, dctx->lb, 16))
 382                 {
 383                 FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, FIPS_R_DRBG_STUCK);
 384                 return 0;
 385                 }
 386         /* Update last block */
 387         memcpy(dctx->lb, pout, 16);
 388         /* Copy to output buffer if needed */
 389         if (outlen < 16)
 390                 memcpy(out, pout, outlen);
 391
 392         return 1;
 393
 394         }
 395
 396 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
 397         {
 398         int rv;
 399         if (!dctx->uninstantiate)
 400                 rv = 1;
 401         else
 402                 rv = dctx->uninstantiate(dctx);
 403         /* Although we'd like to cleanse here we can't because we have to
 404          * test the uninstantiate really zeroes the data.
 405          */
 406         memset(dctx, 0, sizeof(DRBG_CTX));
 407         /* If method has problems uninstantiating, return error */
 408         return rv;
 409         }
 410
 411 int FIPS_drbg_set_callbacks(DRBG_CTX *dctx,
 412         size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char **pout,
 413                                 int entropy, size_t min_len, size_t max_len),
 414         void (*cleanup_entropy)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 415         size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char **pout,
 416                                 int entropy, size_t min_len, size_t max_len),
 417         void (*cleanup_nonce)(DRBG_CTX *ctx, unsigned char *out, size_t olen))
 418         {
 419         if (dctx->status != DRBG_STATUS_UNINITIALISED)
 420                 return 0;
 421         dctx->get_entropy = get_entropy;
 422         dctx->cleanup_entropy = cleanup_entropy;
 423         dctx->get_nonce = get_nonce;
 424         dctx->cleanup_nonce = cleanup_nonce;
 425         return 1;
 426         }
 427
 428 void *FIPS_drbg_get_app_data(DRBG_CTX *dctx)
 429         {
 430         return dctx->app_data;
 431         }
 432
 433 void FIPS_drbg_set_app_data(DRBG_CTX *dctx, void *app_data)
 434         {
 435         dctx->app_data = app_data;
 436         }
 437
 438 size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx)
 439         {
 440         return dctx->blocklength;
 441         }
 442
 443 int FIPS_drbg_get_strength(DRBG_CTX *dctx)
 444         {
 445         return dctx->strength;
 446         }