crypto/evp/evp_rand.c

   1 /*
   2  * Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <openssl/evp.h>
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <openssl/engine.h>
  15 #include <openssl/evp.h>
  16 #include <openssl/x509v3.h>
  17 #include <openssl/rand.h>
  18 #include <openssl/core.h>
  19 #include <openssl/core_names.h>
  20 #include <openssl/crypto.h>
  21 #include "crypto/asn1.h"
  22 #include "crypto/evp.h"
  23 #include "internal/cryptlib.h"
  24 #include "internal/numbers.h"
  25 #include "internal/provider.h"
  26 #include "evp_local.h"
  27
  28 struct evp_rand_st {
  29     OSSL_PROVIDER *prov;
  30     int name_id;
  31     CRYPTO_REF_COUNT refcnt;
  32     CRYPTO_RWLOCK *refcnt_lock;
  33
  34     const OSSL_DISPATCH *dispatch;
  35     OSSL_FUNC_rand_newctx_fn *newctx;
  36     OSSL_FUNC_rand_freectx_fn *freectx;
  37     OSSL_FUNC_rand_instantiate_fn *instantiate;
  38     OSSL_FUNC_rand_uninstantiate_fn *uninstantiate;
  39     OSSL_FUNC_rand_generate_fn *generate;
  40     OSSL_FUNC_rand_reseed_fn *reseed;
  41     OSSL_FUNC_rand_nonce_fn *nonce;
  42     OSSL_FUNC_rand_enable_locking_fn *enable_locking;
  43     OSSL_FUNC_rand_lock_fn *lock;
  44     OSSL_FUNC_rand_unlock_fn *unlock;
  45     OSSL_FUNC_rand_gettable_params_fn *gettable_params;
  46     OSSL_FUNC_rand_gettable_ctx_params_fn *gettable_ctx_params;
  47     OSSL_FUNC_rand_settable_ctx_params_fn *settable_ctx_params;
  48     OSSL_FUNC_rand_get_params_fn *get_params;
  49     OSSL_FUNC_rand_get_ctx_params_fn *get_ctx_params;
  50     OSSL_FUNC_rand_set_ctx_params_fn *set_ctx_params;
  51     OSSL_FUNC_rand_verify_zeroization_fn *verify_zeroization;
  52 } /* EVP_RAND */ ;
  53
  54 static int evp_rand_up_ref(void *vrand)
  55 {
  56     EVP_RAND *rand = (EVP_RAND *)vrand;
  57     int ref = 0;
  58
  59     if (rand != NULL)
  60         return CRYPTO_UP_REF(&rand->refcnt, &ref, rand->refcnt_lock);
  61     return 1;
  62 }
  63
  64 static void evp_rand_free(void *vrand){
  65     EVP_RAND *rand = (EVP_RAND *)vrand;
  66     int ref = 0;
  67
  68     if (rand != NULL) {
  69         CRYPTO_DOWN_REF(&rand->refcnt, &ref, rand->refcnt_lock);
  70         if (ref <= 0) {
  71             ossl_provider_free(rand->prov);
  72             CRYPTO_THREAD_lock_free(rand->refcnt_lock);
  73             OPENSSL_free(rand);
  74         }
  75     }
  76 }
  77
  78 static void *evp_rand_new(void)
  79 {
  80     EVP_RAND *rand = OPENSSL_zalloc(sizeof(*rand));
  81
  82     if (rand == NULL
  83             || (rand->refcnt_lock = CRYPTO_THREAD_lock_new()) == NULL) {
  84         OPENSSL_free(rand);
  85         return NULL;
  86     }
  87     rand->refcnt = 1;
  88     return rand;
  89 }
  90
  91 /* Enable locking of the underlying DRBG/RAND if available */
  92 int EVP_RAND_enable_locking(EVP_RAND_CTX *rand)
  93 {
  94     if (rand->meth->enable_locking != NULL)
  95         return rand->meth->enable_locking(rand->data);
  96     EVPerr(0, EVP_R_LOCKING_NOT_SUPPORTED);
  97     return 0;
  98 }
  99
 100 /* Lock the underlying DRBG/RAND if available */
 101 static int evp_rand_lock(EVP_RAND_CTX *rand)
 102 {
 103     if (rand->meth->lock != NULL)
 104         return rand->meth->lock(rand->data);
 105     return 1;
 106 }
 107
 108 /* Unlock the underlying DRBG/RAND if available */
 109 static void evp_rand_unlock(EVP_RAND_CTX *rand)
 110 {
 111     if (rand->meth->unlock != NULL)
 112         rand->meth->unlock(rand->data);
 113 }
 114
 115 static void *evp_rand_from_dispatch(int name_id,
 116                                     const OSSL_DISPATCH *fns,
 117                                     OSSL_PROVIDER *prov)
 118 {
 119     EVP_RAND *rand = NULL;
 120     int fnrandcnt = 0, fnctxcnt = 0, fnlockcnt = 0;
 121 #ifdef FIPS_MODULE
 122     int fnzeroizecnt = 0;
 123 #endif
 124
 125     if ((rand = evp_rand_new()) == NULL) {
 126         EVPerr(0, ERR_R_MALLOC_FAILURE);
 127         return NULL;
 128     }
 129     rand->name_id = name_id;
 130     rand->dispatch = fns;
 131     for (; fns->function_id != 0; fns++) {
 132         switch (fns->function_id) {
 133         case OSSL_FUNC_RAND_NEWCTX:
 134             if (rand->newctx != NULL)
 135                 break;
 136             rand->newctx = OSSL_FUNC_rand_newctx(fns);
 137             fnctxcnt++;
 138             break;
 139         case OSSL_FUNC_RAND_FREECTX:
 140             if (rand->freectx != NULL)
 141                 break;
 142             rand->freectx = OSSL_FUNC_rand_freectx(fns);
 143             fnctxcnt++;
 144             break;
 145         case OSSL_FUNC_RAND_INSTANTIATE:
 146             if (rand->instantiate != NULL)
 147                 break;
 148             rand->instantiate = OSSL_FUNC_rand_instantiate(fns);
 149             fnrandcnt++;
 150             break;
 151         case OSSL_FUNC_RAND_UNINSTANTIATE:
 152              if (rand->uninstantiate != NULL)
 153                 break;
 154             rand->uninstantiate = OSSL_FUNC_rand_uninstantiate(fns);
 155             fnrandcnt++;
 156             break;
 157         case OSSL_FUNC_RAND_GENERATE:
 158             if (rand->generate != NULL)
 159                 break;
 160             rand->generate = OSSL_FUNC_rand_generate(fns);
 161             fnrandcnt++;
 162             break;
 163         case OSSL_FUNC_RAND_RESEED:
 164             if (rand->reseed != NULL)
 165                 break;
 166             rand->reseed = OSSL_FUNC_rand_reseed(fns);
 167             break;
 168         case OSSL_FUNC_RAND_NONCE:
 169             if (rand->nonce != NULL)
 170                 break;
 171             rand->nonce = OSSL_FUNC_rand_nonce(fns);
 172             break;
 173         case OSSL_FUNC_RAND_ENABLE_LOCKING:
 174             if (rand->enable_locking != NULL)
 175                 break;
 176             rand->enable_locking = OSSL_FUNC_rand_enable_locking(fns);
 177             fnlockcnt++;
 178             break;
 179         case OSSL_FUNC_RAND_LOCK:
 180             if (rand->lock != NULL)
 181                 break;
 182             rand->lock = OSSL_FUNC_rand_lock(fns);
 183             fnlockcnt++;
 184             break;
 185         case OSSL_FUNC_RAND_UNLOCK:
 186             if (rand->unlock != NULL)
 187                 break;
 188             rand->unlock = OSSL_FUNC_rand_unlock(fns);
 189             fnlockcnt++;
 190             break;
 191         case OSSL_FUNC_RAND_GETTABLE_PARAMS:
 192             if (rand->gettable_params != NULL)
 193                 break;
 194             rand->gettable_params =
 195                 OSSL_FUNC_rand_gettable_params(fns);
 196             break;
 197         case OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS:
 198             if (rand->gettable_ctx_params != NULL)
 199                 break;
 200             rand->gettable_ctx_params =
 201                 OSSL_FUNC_rand_gettable_ctx_params(fns);
 202             break;
 203         case OSSL_FUNC_RAND_SETTABLE_CTX_PARAMS:
 204             if (rand->settable_ctx_params != NULL)
 205                 break;
 206             rand->settable_ctx_params =
 207                 OSSL_FUNC_rand_settable_ctx_params(fns);
 208             break;
 209         case OSSL_FUNC_RAND_GET_PARAMS:
 210             if (rand->get_params != NULL)
 211                 break;
 212             rand->get_params = OSSL_FUNC_rand_get_params(fns);
 213             break;
 214         case OSSL_FUNC_RAND_GET_CTX_PARAMS:
 215             if (rand->get_ctx_params != NULL)
 216                 break;
 217             rand->get_ctx_params = OSSL_FUNC_rand_get_ctx_params(fns);
 218             fnctxcnt++;
 219             break;
 220         case OSSL_FUNC_RAND_SET_CTX_PARAMS:
 221             if (rand->set_ctx_params != NULL)
 222                 break;
 223             rand->set_ctx_params = OSSL_FUNC_rand_set_ctx_params(fns);
 224             break;
 225         case OSSL_FUNC_RAND_VERIFY_ZEROIZATION:
 226             if (rand->verify_zeroization != NULL)
 227                 break;
 228             rand->verify_zeroization = OSSL_FUNC_rand_verify_zeroization(fns);
 229 #ifdef FIPS_MODULE
 230             fnzeroizecnt++;
 231 #endif
 232             break;
 233         }
 234     }
 235     /*
 236      * In order to be a consistent set of functions we must have at least
 237      * a complete set of "rand" functions and a complete set of context
 238      * management functions.  In FIPS mode, we also require the zeroization
 239      * verification function.
 240      *
 241      * In addition, if locking can be enabled, we need a complete set of
 242      * locking functions.
 243      */
 244     if (fnrandcnt != 3
 245             || fnctxcnt != 3
 246             || (fnlockcnt != 0 && fnlockcnt != 3)
 247 #ifdef FIPS_MODULE
 248             || fnzeroizecnt != 1
 249 #endif
 250        ) {
 251         evp_rand_free(rand);
 252         ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS);
 253         return NULL;
 254     }
 255
 256     if (prov != NULL && !ossl_provider_up_ref(prov)) {
 257         evp_rand_free(rand);
 258         ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
 259         return NULL;
 260     }
 261     rand->prov = prov;
 262
 263     return rand;
 264 }
 265
 266 EVP_RAND *EVP_RAND_fetch(OPENSSL_CTX *libctx, const char *algorithm,
 267                          const char *properties)
 268 {
 269     return evp_generic_fetch(libctx, OSSL_OP_RAND, algorithm, properties,
 270                              evp_rand_from_dispatch, evp_rand_up_ref,
 271                              evp_rand_free);
 272 }
 273
 274 int EVP_RAND_up_ref(EVP_RAND *rand)
 275 {
 276     return evp_rand_up_ref(rand);
 277 }
 278
 279 void EVP_RAND_free(EVP_RAND *rand)
 280 {
 281     evp_rand_free(rand);
 282 }
 283
 284 int EVP_RAND_number(const EVP_RAND *rand)
 285 {
 286     return rand->name_id;
 287 }
 288
 289 const char *EVP_RAND_name(const EVP_RAND *rand)
 290 {
 291     return evp_first_name(rand->prov, rand->name_id);
 292 }
 293
 294 int EVP_RAND_is_a(const EVP_RAND *rand, const char *name)
 295 {
 296     return evp_is_a(rand->prov, rand->name_id, NULL, name);
 297 }
 298
 299 const OSSL_PROVIDER *EVP_RAND_provider(const EVP_RAND *rand)
 300 {
 301     return rand->prov;
 302 }
 303
 304 int EVP_RAND_get_params(EVP_RAND *rand, OSSL_PARAM params[])
 305 {
 306     if (rand->get_params != NULL)
 307         return rand->get_params(params);
 308     return 1;
 309 }
 310
 311 EVP_RAND_CTX *EVP_RAND_CTX_new(EVP_RAND *rand, EVP_RAND_CTX *parent)
 312 {
 313     EVP_RAND_CTX *ctx;
 314     void *parent_ctx = NULL;
 315     const OSSL_DISPATCH *parent_dispatch = NULL;
 316
 317     if (rand == NULL) {
 318         EVPerr(0, EVP_R_INVALID_NULL_ALGORITHM);
 319         return NULL;
 320     }
 321
 322     ctx = OPENSSL_zalloc(sizeof(*ctx));
 323     if (ctx == NULL) {
 324         EVPerr(0, ERR_R_MALLOC_FAILURE);
 325         return NULL;
 326     }
 327     if (parent != NULL) {
 328         if (!EVP_RAND_enable_locking(parent)) {
 329             EVPerr(0, EVP_R_UNABLE_TO_ENABLE_PARENT_LOCKING);
 330             OPENSSL_free(ctx);
 331             return NULL;
 332         }
 333         parent_ctx = parent->data;
 334         parent_dispatch = parent->meth->dispatch;
 335     }
 336     if ((ctx->data = rand->newctx(ossl_provider_ctx(rand->prov), parent_ctx,
 337                                   parent_dispatch)) == NULL
 338             || !EVP_RAND_up_ref(rand)) {
 339         EVPerr(0, ERR_R_MALLOC_FAILURE);
 340         rand->freectx(ctx->data);
 341         OPENSSL_free(ctx);
 342         return NULL;
 343     }
 344     ctx->meth = rand;
 345     return ctx;
 346 }
 347
 348 void EVP_RAND_CTX_free(EVP_RAND_CTX *ctx)
 349 {
 350     if (ctx != NULL) {
 351         ctx->meth->freectx(ctx->data);
 352         ctx->data = NULL;
 353         EVP_RAND_free(ctx->meth);
 354         OPENSSL_free(ctx);
 355     }
 356 }
 357
 358 EVP_RAND *EVP_RAND_CTX_rand(EVP_RAND_CTX *ctx)
 359 {
 360     return ctx->meth;
 361 }
 362
 363 static int evp_rand_get_ctx_params_locked(EVP_RAND_CTX *ctx,
 364                                           OSSL_PARAM params[])
 365 {
 366     return ctx->meth->get_ctx_params(ctx->data, params);
 367 }
 368
 369 int EVP_RAND_get_ctx_params(EVP_RAND_CTX *ctx, OSSL_PARAM params[])
 370 {
 371     int res;
 372
 373     if (!evp_rand_lock(ctx))
 374         return 0;
 375     res = evp_rand_get_ctx_params_locked(ctx, params);
 376     evp_rand_unlock(ctx);
 377     return res;
 378 }
 379
 380 static int evp_rand_set_ctx_params_locked(EVP_RAND_CTX *ctx,
 381                                           const OSSL_PARAM params[])
 382 {
 383     if (ctx->meth->set_ctx_params != NULL)
 384         return ctx->meth->set_ctx_params(ctx->data, params);
 385     return 1;
 386 }
 387
 388 int EVP_RAND_set_ctx_params(EVP_RAND_CTX *ctx, const OSSL_PARAM params[])
 389 {
 390     int res;
 391
 392     if (!evp_rand_lock(ctx))
 393         return 0;
 394     res = evp_rand_set_ctx_params_locked(ctx, params);
 395     evp_rand_unlock(ctx);
 396     return res;
 397 }
 398
 399 const OSSL_PARAM *EVP_RAND_gettable_params(const EVP_RAND *rand)
 400 {
 401     if (rand->gettable_params == NULL)
 402         return NULL;
 403     return rand->gettable_params(ossl_provider_ctx(EVP_RAND_provider(rand)));
 404 }
 405
 406 const OSSL_PARAM *EVP_RAND_gettable_ctx_params(const EVP_RAND *rand)
 407 {
 408     if (rand->gettable_params == NULL)
 409         return NULL;
 410     return rand->gettable_ctx_params(
 411                ossl_provider_ctx(EVP_RAND_provider(rand)));
 412 }
 413
 414 const OSSL_PARAM *EVP_RAND_settable_ctx_params(const EVP_RAND *rand)
 415 {
 416     if (rand->gettable_params == NULL)
 417         return NULL;
 418     return rand->settable_ctx_params(
 419                ossl_provider_ctx(EVP_RAND_provider(rand)));
 420 }
 421
 422 void EVP_RAND_do_all_provided(OPENSSL_CTX *libctx,
 423                               void (*fn)(EVP_RAND *rand, void *arg),
 424                               void *arg)
 425 {
 426     evp_generic_do_all(libctx, OSSL_OP_RAND,
 427                        (void (*)(void *, void *))fn, arg,
 428                        evp_rand_from_dispatch, evp_rand_free);
 429 }
 430
 431 void EVP_RAND_names_do_all(const EVP_RAND *rand,
 432                            void (*fn)(const char *name, void *data),
 433                            void *data)
 434 {
 435     if (rand->prov != NULL)
 436         evp_names_do_all(rand->prov, rand->name_id, fn, data);
 437 }
 438
 439 static int evp_rand_instantiate_locked
 440     (EVP_RAND_CTX *ctx, unsigned int strength, int prediction_resistance,
 441      const unsigned char *pstr, size_t pstr_len)
 442 {
 443     return ctx->meth->instantiate(ctx->data, strength, prediction_resistance,
 444                                   pstr, pstr_len);
 445 }
 446
 447 int EVP_RAND_instantiate(EVP_RAND_CTX *ctx, unsigned int strength,
 448                          int prediction_resistance,
 449                          const unsigned char *pstr, size_t pstr_len)
 450 {
 451     int res;
 452
 453     if (!evp_rand_lock(ctx))
 454         return 0;
 455     res = evp_rand_instantiate_locked(ctx, strength, prediction_resistance,
 456                                       pstr, pstr_len);
 457     evp_rand_unlock(ctx);
 458     return res;
 459 }
 460
 461 static int evp_rand_uninstantiate_locked(EVP_RAND_CTX *ctx)
 462 {
 463     return ctx->meth->uninstantiate(ctx->data);
 464 }
 465
 466 int EVP_RAND_uninstantiate(EVP_RAND_CTX *ctx)
 467 {
 468     int res;
 469
 470     if (!evp_rand_lock(ctx))
 471         return 0;
 472     res = evp_rand_uninstantiate_locked(ctx);
 473     evp_rand_unlock(ctx);
 474     return res;
 475 }
 476
 477 static int evp_rand_generate_locked(EVP_RAND_CTX *ctx, unsigned char *out,
 478                                     size_t outlen, unsigned int strength,
 479                                     int prediction_resistance,
 480                                     const unsigned char *addin,
 481                                     size_t addin_len)
 482 {
 483     size_t chunk, max_request = 0;
 484     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
 485
 486     params[0] = OSSL_PARAM_construct_size_t(OSSL_DRBG_PARAM_MAX_REQUEST,
 487                                             &max_request);
 488     if (!evp_rand_get_ctx_params_locked(ctx, params)
 489             || max_request == 0) {
 490         EVPerr(0, EVP_R_UNABLE_TO_GET_MAXIMUM_REQUEST_SIZE);
 491         return 0;
 492     }
 493     for (; outlen > 0; outlen -= chunk, out += chunk) {
 494         chunk = outlen > max_request ? max_request : outlen;
 495         if (!ctx->meth->generate(ctx->data, out, chunk, strength,
 496                                  prediction_resistance, addin, addin_len)) {
 497             EVPerr(0, EVP_R_GENERATE_ERROR);
 498             return 0;
 499         }
 500         /*
 501          * Prediction resistance is only relevant the first time around,
 502          * subsequently, the DRBG has already been properly reseeded.
 503          */
 504         prediction_resistance = 0;
 505     }
 506     return 1;
 507 }
 508
 509 int EVP_RAND_generate(EVP_RAND_CTX *ctx, unsigned char *out, size_t outlen,
 510                       unsigned int strength, int prediction_resistance,
 511                       const unsigned char *addin, size_t addin_len)
 512 {
 513     int res;
 514
 515     if (!evp_rand_lock(ctx))
 516         return 0;
 517     res = evp_rand_generate_locked(ctx, out, outlen, strength,
 518                                    prediction_resistance, addin, addin_len);
 519     evp_rand_unlock(ctx);
 520     return res;
 521 }
 522
 523 static int evp_rand_reseed_locked(EVP_RAND_CTX *ctx, int prediction_resistance,
 524                                   const unsigned char *ent, size_t ent_len,
 525                                   const unsigned char *addin, size_t addin_len)
 526 {
 527     if (ctx->meth->reseed != NULL)
 528         return ctx->meth->reseed(ctx->data, prediction_resistance,
 529                                  ent, ent_len, addin, addin_len);
 530     return 1;
 531 }
 532
 533 int EVP_RAND_reseed(EVP_RAND_CTX *ctx, int prediction_resistance,
 534                     const unsigned char *ent, size_t ent_len,
 535                     const unsigned char *addin, size_t addin_len)
 536 {
 537     int res;
 538
 539     if (!evp_rand_lock(ctx))
 540         return 0;
 541     res = evp_rand_reseed_locked(ctx, prediction_resistance,
 542                                  ent, ent_len, addin, addin_len);
 543     evp_rand_unlock(ctx);
 544     return res;
 545 }
 546
 547 static unsigned int evp_rand_strength_locked(EVP_RAND_CTX *ctx)
 548 {
 549     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
 550     unsigned int strength = 0;
 551
 552     params[0] = OSSL_PARAM_construct_uint(OSSL_RAND_PARAM_STRENGTH, &strength);
 553     if (!evp_rand_get_ctx_params_locked(ctx, params))
 554         return 0;
 555     return strength;
 556 }
 557
 558 unsigned int EVP_RAND_strength(EVP_RAND_CTX *ctx)
 559 {
 560     unsigned int res;
 561
 562     if (!evp_rand_lock(ctx))
 563         return 0;
 564     res = evp_rand_strength_locked(ctx);
 565     evp_rand_unlock(ctx);
 566     return res;
 567 }
 568
 569 static int evp_rand_nonce_locked(EVP_RAND_CTX *ctx, unsigned char *out,
 570                                  size_t outlen)
 571 {
 572     unsigned int str = evp_rand_strength_locked(ctx);
 573
 574     if (ctx->meth->nonce == NULL)
 575         return 0;
 576     if (ctx->meth->nonce(ctx->data, out, str, outlen, outlen))
 577         return 1;
 578     return evp_rand_generate_locked(ctx, out, outlen, str, 0, NULL, 0);
 579 }
 580
 581 int EVP_RAND_nonce(EVP_RAND_CTX *ctx, unsigned char *out, size_t outlen)
 582 {
 583     int res;
 584
 585     if (!evp_rand_lock(ctx))
 586         return 0;
 587     res = evp_rand_nonce_locked(ctx, out, outlen);
 588     evp_rand_unlock(ctx);
 589     return res;
 590 }
 591
 592 int EVP_RAND_state(EVP_RAND_CTX *ctx)
 593 {
 594     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
 595     int state;
 596
 597     params[0] = OSSL_PARAM_construct_int(OSSL_RAND_PARAM_STATE, &state);
 598     if (!EVP_RAND_get_ctx_params(ctx, params))
 599         state = EVP_RAND_STATE_ERROR;
 600     return state;
 601 }
 602
 603 static int evp_rand_verify_zeroization_locked(EVP_RAND_CTX *ctx)
 604 {
 605     if (ctx->meth->verify_zeroization != NULL)
 606         return ctx->meth->verify_zeroization(ctx->data);
 607     return 0;
 608 }
 609
 610 int EVP_RAND_verify_zeroization(EVP_RAND_CTX *ctx)
 611 {
 612     int res;
 613
 614     if (!evp_rand_lock(ctx))
 615         return 0;
 616     res = evp_rand_verify_zeroization_locked(ctx);
 617     evp_rand_unlock(ctx);
 618     return res;
 619 }