crypto/evp/evp_rand.c

   1 /*
   2  * Copyright 2020-2023 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 <stdio.h>
  11 #include <stdlib.h>
  12 #include <openssl/evp.h>
  13 #include <openssl/rand.h>
  14 #include <openssl/core.h>
  15 #include <openssl/core_names.h>
  16 #include <openssl/crypto.h>
  17 #include "internal/cryptlib.h"
  18 #include "internal/numbers.h"
  19 #include "internal/provider.h"
  20 #include "internal/core.h"
  21 #include "crypto/evp.h"
  22 #include "evp_local.h"
  23
  24 struct evp_rand_st {
  25     OSSL_PROVIDER *prov;
  26     int name_id;
  27     char *type_name;
  28     const char *description;
  29     CRYPTO_REF_COUNT refcnt;
  30
  31     const OSSL_DISPATCH *dispatch;
  32     OSSL_FUNC_rand_newctx_fn *newctx;
  33     OSSL_FUNC_rand_freectx_fn *freectx;
  34     OSSL_FUNC_rand_instantiate_fn *instantiate;
  35     OSSL_FUNC_rand_uninstantiate_fn *uninstantiate;
  36     OSSL_FUNC_rand_generate_fn *generate;
  37     OSSL_FUNC_rand_reseed_fn *reseed;
  38     OSSL_FUNC_rand_nonce_fn *nonce;
  39     OSSL_FUNC_rand_enable_locking_fn *enable_locking;
  40     OSSL_FUNC_rand_lock_fn *lock;
  41     OSSL_FUNC_rand_unlock_fn *unlock;
  42     OSSL_FUNC_rand_gettable_params_fn *gettable_params;
  43     OSSL_FUNC_rand_gettable_ctx_params_fn *gettable_ctx_params;
  44     OSSL_FUNC_rand_settable_ctx_params_fn *settable_ctx_params;
  45     OSSL_FUNC_rand_get_params_fn *get_params;
  46     OSSL_FUNC_rand_get_ctx_params_fn *get_ctx_params;
  47     OSSL_FUNC_rand_set_ctx_params_fn *set_ctx_params;
  48     OSSL_FUNC_rand_verify_zeroization_fn *verify_zeroization;
  49 } /* EVP_RAND */ ;
  50
  51 static int evp_rand_up_ref(void *vrand)
  52 {
  53     EVP_RAND *rand = (EVP_RAND *)vrand;
  54     int ref = 0;
  55
  56     if (rand != NULL)
  57         return CRYPTO_UP_REF(&rand->refcnt, &ref);
  58     return 1;
  59 }
  60
  61 static void evp_rand_free(void *vrand)
  62 {
  63     EVP_RAND *rand = (EVP_RAND *)vrand;
  64     int ref = 0;
  65
  66     if (rand == NULL)
  67         return;
  68     CRYPTO_DOWN_REF(&rand->refcnt, &ref);
  69     if (ref > 0)
  70         return;
  71     OPENSSL_free(rand->type_name);
  72     ossl_provider_free(rand->prov);
  73     CRYPTO_FREE_REF(&rand->refcnt);
  74     OPENSSL_free(rand);
  75 }
  76
  77 static void *evp_rand_new(void)
  78 {
  79     EVP_RAND *rand = OPENSSL_zalloc(sizeof(*rand));
  80
  81     if (rand == NULL)
  82         return NULL;
  83
  84     if (!CRYPTO_NEW_REF(&rand->refcnt, 1)) {
  85         OPENSSL_free(rand);
  86         return NULL;
  87     }
  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->algctx);
  96     ERR_raise(ERR_LIB_EVP, 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->algctx);
 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->algctx);
 113 }
 114
 115 static void *evp_rand_from_algorithm(int name_id,
 116                                      const OSSL_ALGORITHM *algodef,
 117                                      OSSL_PROVIDER *prov)
 118 {
 119     const OSSL_DISPATCH *fns = algodef->implementation;
 120     EVP_RAND *rand = NULL;
 121     int fnrandcnt = 0, fnctxcnt = 0, fnlockcnt = 0, fnenablelockcnt = 0;
 122 #ifdef FIPS_MODULE
 123     int fnzeroizecnt = 0;
 124 #endif
 125
 126     if ((rand = evp_rand_new()) == NULL) {
 127         ERR_raise(ERR_LIB_EVP, ERR_R_EVP_LIB);
 128         return NULL;
 129     }
 130     rand->name_id = name_id;
 131     if ((rand->type_name = ossl_algorithm_get1_first_name(algodef)) == NULL) {
 132         evp_rand_free(rand);
 133         return NULL;
 134     }
 135     rand->description = algodef->algorithm_description;
 136     rand->dispatch = fns;
 137     for (; fns->function_id != 0; fns++) {
 138         switch (fns->function_id) {
 139         case OSSL_FUNC_RAND_NEWCTX:
 140             if (rand->newctx != NULL)
 141                 break;
 142             rand->newctx = OSSL_FUNC_rand_newctx(fns);
 143             fnctxcnt++;
 144             break;
 145         case OSSL_FUNC_RAND_FREECTX:
 146             if (rand->freectx != NULL)
 147                 break;
 148             rand->freectx = OSSL_FUNC_rand_freectx(fns);
 149             fnctxcnt++;
 150             break;
 151         case OSSL_FUNC_RAND_INSTANTIATE:
 152             if (rand->instantiate != NULL)
 153                 break;
 154             rand->instantiate = OSSL_FUNC_rand_instantiate(fns);
 155             fnrandcnt++;
 156             break;
 157         case OSSL_FUNC_RAND_UNINSTANTIATE:
 158              if (rand->uninstantiate != NULL)
 159                 break;
 160             rand->uninstantiate = OSSL_FUNC_rand_uninstantiate(fns);
 161             fnrandcnt++;
 162             break;
 163         case OSSL_FUNC_RAND_GENERATE:
 164             if (rand->generate != NULL)
 165                 break;
 166             rand->generate = OSSL_FUNC_rand_generate(fns);
 167             fnrandcnt++;
 168             break;
 169         case OSSL_FUNC_RAND_RESEED:
 170             if (rand->reseed != NULL)
 171                 break;
 172             rand->reseed = OSSL_FUNC_rand_reseed(fns);
 173             break;
 174         case OSSL_FUNC_RAND_NONCE:
 175             if (rand->nonce != NULL)
 176                 break;
 177             rand->nonce = OSSL_FUNC_rand_nonce(fns);
 178             break;
 179         case OSSL_FUNC_RAND_ENABLE_LOCKING:
 180             if (rand->enable_locking != NULL)
 181                 break;
 182             rand->enable_locking = OSSL_FUNC_rand_enable_locking(fns);
 183             fnenablelockcnt++;
 184             break;
 185         case OSSL_FUNC_RAND_LOCK:
 186             if (rand->lock != NULL)
 187                 break;
 188             rand->lock = OSSL_FUNC_rand_lock(fns);
 189             fnlockcnt++;
 190             break;
 191         case OSSL_FUNC_RAND_UNLOCK:
 192             if (rand->unlock != NULL)
 193                 break;
 194             rand->unlock = OSSL_FUNC_rand_unlock(fns);
 195             fnlockcnt++;
 196             break;
 197         case OSSL_FUNC_RAND_GETTABLE_PARAMS:
 198             if (rand->gettable_params != NULL)
 199                 break;
 200             rand->gettable_params =
 201                 OSSL_FUNC_rand_gettable_params(fns);
 202             break;
 203         case OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS:
 204             if (rand->gettable_ctx_params != NULL)
 205                 break;
 206             rand->gettable_ctx_params =
 207                 OSSL_FUNC_rand_gettable_ctx_params(fns);
 208             break;
 209         case OSSL_FUNC_RAND_SETTABLE_CTX_PARAMS:
 210             if (rand->settable_ctx_params != NULL)
 211                 break;
 212             rand->settable_ctx_params =
 213                 OSSL_FUNC_rand_settable_ctx_params(fns);
 214             break;
 215         case OSSL_FUNC_RAND_GET_PARAMS:
 216             if (rand->get_params != NULL)
 217                 break;
 218             rand->get_params = OSSL_FUNC_rand_get_params(fns);
 219             break;
 220         case OSSL_FUNC_RAND_GET_CTX_PARAMS:
 221             if (rand->get_ctx_params != NULL)
 222                 break;
 223             rand->get_ctx_params = OSSL_FUNC_rand_get_ctx_params(fns);
 224             fnctxcnt++;
 225             break;
 226         case OSSL_FUNC_RAND_SET_CTX_PARAMS:
 227             if (rand->set_ctx_params != NULL)
 228                 break;
 229             rand->set_ctx_params = OSSL_FUNC_rand_set_ctx_params(fns);
 230             break;
 231         case OSSL_FUNC_RAND_VERIFY_ZEROIZATION:
 232             if (rand->verify_zeroization != NULL)
 233                 break;
 234             rand->verify_zeroization = OSSL_FUNC_rand_verify_zeroization(fns);
 235 #ifdef FIPS_MODULE
 236             fnzeroizecnt++;
 237 #endif
 238             break;
 239         }
 240     }
 241     /*
 242      * In order to be a consistent set of functions we must have at least
 243      * a complete set of "rand" functions and a complete set of context
 244      * management functions.  In FIPS mode, we also require the zeroization
 245      * verification function.
 246      *
 247      * In addition, if locking can be enabled, we need a complete set of
 248      * locking functions.
 249      */
 250     if (fnrandcnt != 3
 251             || fnctxcnt != 3
 252             || (fnenablelockcnt != 0 && fnenablelockcnt != 1)
 253             || (fnlockcnt != 0 && fnlockcnt != 2)
 254 #ifdef FIPS_MODULE
 255             || fnzeroizecnt != 1
 256 #endif
 257        ) {
 258         evp_rand_free(rand);
 259         ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS);
 260         return NULL;
 261     }
 262
 263     if (prov != NULL && !ossl_provider_up_ref(prov)) {
 264         evp_rand_free(rand);
 265         ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
 266         return NULL;
 267     }
 268     rand->prov = prov;
 269
 270     return rand;
 271 }
 272
 273 EVP_RAND *EVP_RAND_fetch(OSSL_LIB_CTX *libctx, const char *algorithm,
 274                          const char *properties)
 275 {
 276     return evp_generic_fetch(libctx, OSSL_OP_RAND, algorithm, properties,
 277                              evp_rand_from_algorithm, evp_rand_up_ref,
 278                              evp_rand_free);
 279 }
 280
 281 int EVP_RAND_up_ref(EVP_RAND *rand)
 282 {
 283     return evp_rand_up_ref(rand);
 284 }
 285
 286 void EVP_RAND_free(EVP_RAND *rand)
 287 {
 288     evp_rand_free(rand);
 289 }
 290
 291 int evp_rand_get_number(const EVP_RAND *rand)
 292 {
 293     return rand->name_id;
 294 }
 295
 296 const char *EVP_RAND_get0_name(const EVP_RAND *rand)
 297 {
 298     return rand->type_name;
 299 }
 300
 301 const char *EVP_RAND_get0_description(const EVP_RAND *rand)
 302 {
 303     return rand->description;
 304 }
 305
 306 int EVP_RAND_is_a(const EVP_RAND *rand, const char *name)
 307 {
 308     return rand != NULL && evp_is_a(rand->prov, rand->name_id, NULL, name);
 309 }
 310
 311 const OSSL_PROVIDER *EVP_RAND_get0_provider(const EVP_RAND *rand)
 312 {
 313     return rand->prov;
 314 }
 315
 316 int EVP_RAND_get_params(EVP_RAND *rand, OSSL_PARAM params[])
 317 {
 318     if (rand->get_params != NULL)
 319         return rand->get_params(params);
 320     return 1;
 321 }
 322
 323 int EVP_RAND_CTX_up_ref(EVP_RAND_CTX *ctx)
 324 {
 325     int ref = 0;
 326
 327     return CRYPTO_UP_REF(&ctx->refcnt, &ref);
 328 }
 329
 330 EVP_RAND_CTX *EVP_RAND_CTX_new(EVP_RAND *rand, EVP_RAND_CTX *parent)
 331 {
 332     EVP_RAND_CTX *ctx;
 333     void *parent_ctx = NULL;
 334     const OSSL_DISPATCH *parent_dispatch = NULL;
 335
 336     if (rand == NULL) {
 337         ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_NULL_ALGORITHM);
 338         return NULL;
 339     }
 340
 341     ctx = OPENSSL_zalloc(sizeof(*ctx));
 342     if (ctx == NULL)
 343         return NULL;
 344     if (!CRYPTO_NEW_REF(&ctx->refcnt, 1)) {
 345         OPENSSL_free(ctx);
 346         return NULL;
 347     }
 348     if (parent != NULL) {
 349         if (!EVP_RAND_CTX_up_ref(parent)) {
 350             ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
 351             CRYPTO_FREE_REF(&ctx->refcnt);
 352             OPENSSL_free(ctx);
 353             return NULL;
 354         }
 355         parent_ctx = parent->algctx;
 356         parent_dispatch = parent->meth->dispatch;
 357     }
 358     if ((ctx->algctx = rand->newctx(ossl_provider_ctx(rand->prov), parent_ctx,
 359                                     parent_dispatch)) == NULL
 360             || !EVP_RAND_up_ref(rand)) {
 361         ERR_raise(ERR_LIB_EVP, ERR_R_EVP_LIB);
 362         rand->freectx(ctx->algctx);
 363         CRYPTO_FREE_REF(&ctx->refcnt);
 364         OPENSSL_free(ctx);
 365         EVP_RAND_CTX_free(parent);
 366         return NULL;
 367     }
 368     ctx->meth = rand;
 369     ctx->parent = parent;
 370     return ctx;
 371 }
 372
 373 void EVP_RAND_CTX_free(EVP_RAND_CTX *ctx)
 374 {
 375     int ref = 0;
 376     EVP_RAND_CTX *parent;
 377
 378     if (ctx == NULL)
 379         return;
 380
 381     CRYPTO_DOWN_REF(&ctx->refcnt, &ref);
 382     if (ref > 0)
 383         return;
 384     parent = ctx->parent;
 385     ctx->meth->freectx(ctx->algctx);
 386     ctx->algctx = NULL;
 387     EVP_RAND_free(ctx->meth);
 388     CRYPTO_FREE_REF(&ctx->refcnt);
 389     OPENSSL_free(ctx);
 390     EVP_RAND_CTX_free(parent);
 391 }
 392
 393 EVP_RAND *EVP_RAND_CTX_get0_rand(EVP_RAND_CTX *ctx)
 394 {
 395     return ctx->meth;
 396 }
 397
 398 static int evp_rand_get_ctx_params_locked(EVP_RAND_CTX *ctx,
 399                                           OSSL_PARAM params[])
 400 {
 401     return ctx->meth->get_ctx_params(ctx->algctx, params);
 402 }
 403
 404 int EVP_RAND_CTX_get_params(EVP_RAND_CTX *ctx, OSSL_PARAM params[])
 405 {
 406     int res;
 407
 408     if (!evp_rand_lock(ctx))
 409         return 0;
 410     res = evp_rand_get_ctx_params_locked(ctx, params);
 411     evp_rand_unlock(ctx);
 412     return res;
 413 }
 414
 415 static int evp_rand_set_ctx_params_locked(EVP_RAND_CTX *ctx,
 416                                           const OSSL_PARAM params[])
 417 {
 418     if (ctx->meth->set_ctx_params != NULL)
 419         return ctx->meth->set_ctx_params(ctx->algctx, params);
 420     return 1;
 421 }
 422
 423 int EVP_RAND_CTX_set_params(EVP_RAND_CTX *ctx, const OSSL_PARAM params[])
 424 {
 425     int res;
 426
 427     if (!evp_rand_lock(ctx))
 428         return 0;
 429     res = evp_rand_set_ctx_params_locked(ctx, params);
 430     evp_rand_unlock(ctx);
 431     return res;
 432 }
 433
 434 const OSSL_PARAM *EVP_RAND_gettable_params(const EVP_RAND *rand)
 435 {
 436     if (rand->gettable_params == NULL)
 437         return NULL;
 438     return rand->gettable_params(ossl_provider_ctx(EVP_RAND_get0_provider(rand)));
 439 }
 440
 441 const OSSL_PARAM *EVP_RAND_gettable_ctx_params(const EVP_RAND *rand)
 442 {
 443     void *provctx;
 444
 445     if (rand->gettable_ctx_params == NULL)
 446         return NULL;
 447     provctx = ossl_provider_ctx(EVP_RAND_get0_provider(rand));
 448     return rand->gettable_ctx_params(NULL, provctx);
 449 }
 450
 451 const OSSL_PARAM *EVP_RAND_settable_ctx_params(const EVP_RAND *rand)
 452 {
 453     void *provctx;
 454
 455     if (rand->settable_ctx_params == NULL)
 456         return NULL;
 457     provctx = ossl_provider_ctx(EVP_RAND_get0_provider(rand));
 458     return rand->settable_ctx_params(NULL, provctx);
 459 }
 460
 461 const OSSL_PARAM *EVP_RAND_CTX_gettable_params(EVP_RAND_CTX *ctx)
 462 {
 463     void *provctx;
 464
 465     if (ctx->meth->gettable_ctx_params == NULL)
 466         return NULL;
 467     provctx = ossl_provider_ctx(EVP_RAND_get0_provider(ctx->meth));
 468     return ctx->meth->gettable_ctx_params(ctx->algctx, provctx);
 469 }
 470
 471 const OSSL_PARAM *EVP_RAND_CTX_settable_params(EVP_RAND_CTX *ctx)
 472 {
 473     void *provctx;
 474
 475     if (ctx->meth->settable_ctx_params == NULL)
 476         return NULL;
 477     provctx = ossl_provider_ctx(EVP_RAND_get0_provider(ctx->meth));
 478     return ctx->meth->settable_ctx_params(ctx->algctx, provctx);
 479 }
 480
 481 void EVP_RAND_do_all_provided(OSSL_LIB_CTX *libctx,
 482                               void (*fn)(EVP_RAND *rand, void *arg),
 483                               void *arg)
 484 {
 485     evp_generic_do_all(libctx, OSSL_OP_RAND,
 486                        (void (*)(void *, void *))fn, arg,
 487                        evp_rand_from_algorithm, evp_rand_up_ref,
 488                        evp_rand_free);
 489 }
 490
 491 int EVP_RAND_names_do_all(const EVP_RAND *rand,
 492                           void (*fn)(const char *name, void *data),
 493                           void *data)
 494 {
 495     if (rand->prov != NULL)
 496         return evp_names_do_all(rand->prov, rand->name_id, fn, data);
 497
 498     return 1;
 499 }
 500
 501 static int evp_rand_instantiate_locked
 502     (EVP_RAND_CTX *ctx, unsigned int strength, int prediction_resistance,
 503      const unsigned char *pstr, size_t pstr_len, const OSSL_PARAM params[])
 504 {
 505     return ctx->meth->instantiate(ctx->algctx, strength, prediction_resistance,
 506                                   pstr, pstr_len, params);
 507 }
 508
 509 int EVP_RAND_instantiate(EVP_RAND_CTX *ctx, unsigned int strength,
 510                          int prediction_resistance,
 511                          const unsigned char *pstr, size_t pstr_len,
 512                          const OSSL_PARAM params[])
 513 {
 514     int res;
 515
 516     if (!evp_rand_lock(ctx))
 517         return 0;
 518     res = evp_rand_instantiate_locked(ctx, strength, prediction_resistance,
 519                                       pstr, pstr_len, params);
 520     evp_rand_unlock(ctx);
 521     return res;
 522 }
 523
 524 static int evp_rand_uninstantiate_locked(EVP_RAND_CTX *ctx)
 525 {
 526     return ctx->meth->uninstantiate(ctx->algctx);
 527 }
 528
 529 int EVP_RAND_uninstantiate(EVP_RAND_CTX *ctx)
 530 {
 531     int res;
 532
 533     if (!evp_rand_lock(ctx))
 534         return 0;
 535     res = evp_rand_uninstantiate_locked(ctx);
 536     evp_rand_unlock(ctx);
 537     return res;
 538 }
 539
 540 static int evp_rand_generate_locked(EVP_RAND_CTX *ctx, unsigned char *out,
 541                                     size_t outlen, unsigned int strength,
 542                                     int prediction_resistance,
 543                                     const unsigned char *addin,
 544                                     size_t addin_len)
 545 {
 546     size_t chunk, max_request = 0;
 547     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
 548
 549     params[0] = OSSL_PARAM_construct_size_t(OSSL_RAND_PARAM_MAX_REQUEST,
 550                                             &max_request);
 551     if (!evp_rand_get_ctx_params_locked(ctx, params)
 552             || max_request == 0) {
 553         ERR_raise(ERR_LIB_EVP, EVP_R_UNABLE_TO_GET_MAXIMUM_REQUEST_SIZE);
 554         return 0;
 555     }
 556     for (; outlen > 0; outlen -= chunk, out += chunk) {
 557         chunk = outlen > max_request ? max_request : outlen;
 558         if (!ctx->meth->generate(ctx->algctx, out, chunk, strength,
 559                                  prediction_resistance, addin, addin_len)) {
 560             ERR_raise(ERR_LIB_EVP, EVP_R_GENERATE_ERROR);
 561             return 0;
 562         }
 563         /*
 564          * Prediction resistance is only relevant the first time around,
 565          * subsequently, the DRBG has already been properly reseeded.
 566          */
 567         prediction_resistance = 0;
 568     }
 569     return 1;
 570 }
 571
 572 int EVP_RAND_generate(EVP_RAND_CTX *ctx, unsigned char *out, size_t outlen,
 573                       unsigned int strength, int prediction_resistance,
 574                       const unsigned char *addin, size_t addin_len)
 575 {
 576     int res;
 577
 578     if (!evp_rand_lock(ctx))
 579         return 0;
 580     res = evp_rand_generate_locked(ctx, out, outlen, strength,
 581                                    prediction_resistance, addin, addin_len);
 582     evp_rand_unlock(ctx);
 583     return res;
 584 }
 585
 586 static int evp_rand_reseed_locked(EVP_RAND_CTX *ctx, int prediction_resistance,
 587                                   const unsigned char *ent, size_t ent_len,
 588                                   const unsigned char *addin, size_t addin_len)
 589 {
 590     if (ctx->meth->reseed != NULL)
 591         return ctx->meth->reseed(ctx->algctx, prediction_resistance,
 592                                  ent, ent_len, addin, addin_len);
 593     return 1;
 594 }
 595
 596 int EVP_RAND_reseed(EVP_RAND_CTX *ctx, int prediction_resistance,
 597                     const unsigned char *ent, size_t ent_len,
 598                     const unsigned char *addin, size_t addin_len)
 599 {
 600     int res;
 601
 602     if (!evp_rand_lock(ctx))
 603         return 0;
 604     res = evp_rand_reseed_locked(ctx, prediction_resistance,
 605                                  ent, ent_len, addin, addin_len);
 606     evp_rand_unlock(ctx);
 607     return res;
 608 }
 609
 610 static unsigned int evp_rand_strength_locked(EVP_RAND_CTX *ctx)
 611 {
 612     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
 613     unsigned int strength = 0;
 614
 615     params[0] = OSSL_PARAM_construct_uint(OSSL_RAND_PARAM_STRENGTH, &strength);
 616     if (!evp_rand_get_ctx_params_locked(ctx, params))
 617         return 0;
 618     return strength;
 619 }
 620
 621 unsigned int EVP_RAND_get_strength(EVP_RAND_CTX *ctx)
 622 {
 623     unsigned int res;
 624
 625     if (!evp_rand_lock(ctx))
 626         return 0;
 627     res = evp_rand_strength_locked(ctx);
 628     evp_rand_unlock(ctx);
 629     return res;
 630 }
 631
 632 static int evp_rand_nonce_locked(EVP_RAND_CTX *ctx, unsigned char *out,
 633                                  size_t outlen)
 634 {
 635     unsigned int str = evp_rand_strength_locked(ctx);
 636
 637     if (ctx->meth->nonce == NULL)
 638         return 0;
 639     if (ctx->meth->nonce(ctx->algctx, out, str, outlen, outlen))
 640         return 1;
 641     return evp_rand_generate_locked(ctx, out, outlen, str, 0, NULL, 0);
 642 }
 643
 644 int EVP_RAND_nonce(EVP_RAND_CTX *ctx, unsigned char *out, size_t outlen)
 645 {
 646     int res;
 647
 648     if (!evp_rand_lock(ctx))
 649         return 0;
 650     res = evp_rand_nonce_locked(ctx, out, outlen);
 651     evp_rand_unlock(ctx);
 652     return res;
 653 }
 654
 655 int EVP_RAND_get_state(EVP_RAND_CTX *ctx)
 656 {
 657     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
 658     int state;
 659
 660     params[0] = OSSL_PARAM_construct_int(OSSL_RAND_PARAM_STATE, &state);
 661     if (!EVP_RAND_CTX_get_params(ctx, params))
 662         state = EVP_RAND_STATE_ERROR;
 663     return state;
 664 }
 665
 666 static int evp_rand_verify_zeroization_locked(EVP_RAND_CTX *ctx)
 667 {
 668     if (ctx->meth->verify_zeroization != NULL)
 669         return ctx->meth->verify_zeroization(ctx->algctx);
 670     return 0;
 671 }
 672
 673 int EVP_RAND_verify_zeroization(EVP_RAND_CTX *ctx)
 674 {
 675     int res;
 676
 677     if (!evp_rand_lock(ctx))
 678         return 0;
 679     res = evp_rand_verify_zeroization_locked(ctx);
 680     evp_rand_unlock(ctx);
 681     return res;
 682 }