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 static int evp_rand_up_ref(void *vrand)
  29 {
  30     EVP_RAND *rand = (EVP_RAND *)vrand;
  31     int ref = 0;
  32
  33     if (rand != NULL)
  34         return CRYPTO_UP_REF(&rand->refcnt, &ref, rand->refcnt_lock);
  35     return 1;
  36 }
  37
  38 static void evp_rand_free(void *vrand){
  39     EVP_RAND *rand = (EVP_RAND *)vrand;
  40     int ref = 0;
  41
  42     if (rand != NULL) {
  43         CRYPTO_DOWN_REF(&rand->refcnt, &ref, rand->refcnt_lock);
  44         if (ref <= 0) {
  45             ossl_provider_free(rand->prov);
  46             CRYPTO_THREAD_lock_free(rand->refcnt_lock);
  47             OPENSSL_free(rand);
  48         }
  49     }
  50 }
  51
  52 static void *evp_rand_new(void)
  53 {
  54     EVP_RAND *rand = OPENSSL_zalloc(sizeof(*rand));
  55
  56     if (rand == NULL
  57             || (rand->refcnt_lock = CRYPTO_THREAD_lock_new()) == NULL) {
  58         OPENSSL_free(rand);
  59         return NULL;
  60     }
  61     rand->refcnt = 1;
  62     return rand;
  63 }
  64
  65 /* Enable locking of the underlying DRBG/RAND if available */
  66 int EVP_RAND_enable_locking(EVP_RAND_CTX *rand)
  67 {
  68     if (rand->meth->enable_locking != NULL)
  69         return rand->meth->enable_locking(rand->data);
  70     EVPerr(0, EVP_R_LOCKING_NOT_SUPPORTED);
  71     return 0;
  72 }
  73
  74 /* Lock the underlying DRBG/RAND if available */
  75 static int evp_rand_lock(EVP_RAND_CTX *rand)
  76 {
  77     if (rand->meth->lock != NULL)
  78         return rand->meth->lock(rand->data);
  79     return 1;
  80 }
  81
  82 /* Unlock the underlying DRBG/RAND if available */
  83 static void evp_rand_unlock(EVP_RAND_CTX *rand)
  84 {
  85     if (rand->meth->unlock != NULL)
  86         rand->meth->unlock(rand->data);
  87 }
  88
  89 static void *evp_rand_from_dispatch(int name_id,
  90                                     const OSSL_DISPATCH *fns,
  91                                     OSSL_PROVIDER *prov)
  92 {
  93     EVP_RAND *rand = NULL;
  94     int fnrandcnt = 0, fnctxcnt = 0, fnlockcnt = 0;
  95 #ifdef FIPS_MODULE
  96     int fnzeroizecnt = 0;
  97 #endif
  98
  99     if ((rand = evp_rand_new()) == NULL) {
 100         EVPerr(0, ERR_R_MALLOC_FAILURE);
 101         return NULL;
 102     }
 103     rand->name_id = name_id;
 104     rand->dispatch = fns;
 105     for (; fns->function_id != 0; fns++) {
 106         switch (fns->function_id) {
 107         case OSSL_FUNC_RAND_NEWCTX:
 108             if (rand->newctx != NULL)
 109                 break;
 110             rand->newctx = OSSL_get_OP_rand_newctx(fns);
 111             fnctxcnt++;
 112             break;
 113         case OSSL_FUNC_RAND_FREECTX:
 114             if (rand->freectx != NULL)
 115                 break;
 116             rand->freectx = OSSL_get_OP_rand_freectx(fns);
 117             fnctxcnt++;
 118             break;
 119         case OSSL_FUNC_RAND_INSTANTIATE:
 120             if (rand->instantiate != NULL)
 121                 break;
 122             rand->instantiate = OSSL_get_OP_rand_instantiate(fns);
 123             fnrandcnt++;
 124             break;
 125         case OSSL_FUNC_RAND_UNINSTANTIATE:
 126              if (rand->uninstantiate != NULL)
 127                 break;
 128             rand->uninstantiate = OSSL_get_OP_rand_uninstantiate(fns);
 129             fnrandcnt++;
 130             break;
 131         case OSSL_FUNC_RAND_GENERATE:
 132             if (rand->generate != NULL)
 133                 break;
 134             rand->generate = OSSL_get_OP_rand_generate(fns);
 135             fnrandcnt++;
 136             break;
 137         case OSSL_FUNC_RAND_RESEED:
 138             if (rand->reseed != NULL)
 139                 break;
 140             rand->reseed = OSSL_get_OP_rand_reseed(fns);
 141             break;
 142         case OSSL_FUNC_RAND_NONCE:
 143             if (rand->nonce != NULL)
 144                 break;
 145             rand->nonce = OSSL_get_OP_rand_nonce(fns);
 146             break;
 147         case OSSL_FUNC_RAND_SET_CALLBACKS:
 148             if (rand->set_callbacks != NULL)
 149                 break;
 150             rand->set_callbacks = OSSL_get_OP_rand_set_callbacks(fns);
 151             break;
 152         case OSSL_FUNC_RAND_ENABLE_LOCKING:
 153             if (rand->enable_locking != NULL)
 154                 break;
 155             rand->enable_locking = OSSL_get_OP_rand_enable_locking(fns);
 156             fnlockcnt++;
 157             break;
 158         case OSSL_FUNC_RAND_LOCK:
 159             if (rand->lock != NULL)
 160                 break;
 161             rand->lock = OSSL_get_OP_rand_lock(fns);
 162             fnlockcnt++;
 163             break;
 164         case OSSL_FUNC_RAND_UNLOCK:
 165             if (rand->unlock != NULL)
 166                 break;
 167             rand->unlock = OSSL_get_OP_rand_unlock(fns);
 168             fnlockcnt++;
 169             break;
 170         case OSSL_FUNC_RAND_GETTABLE_PARAMS:
 171             if (rand->gettable_params != NULL)
 172                 break;
 173             rand->gettable_params =
 174                 OSSL_get_OP_rand_gettable_params(fns);
 175             break;
 176         case OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS:
 177             if (rand->gettable_ctx_params != NULL)
 178                 break;
 179             rand->gettable_ctx_params =
 180                 OSSL_get_OP_rand_gettable_ctx_params(fns);
 181             break;
 182         case OSSL_FUNC_RAND_SETTABLE_CTX_PARAMS:
 183             if (rand->settable_ctx_params != NULL)
 184                 break;
 185             rand->settable_ctx_params =
 186                 OSSL_get_OP_rand_settable_ctx_params(fns);
 187             break;
 188         case OSSL_FUNC_RAND_GET_PARAMS:
 189             if (rand->get_params != NULL)
 190                 break;
 191             rand->get_params = OSSL_get_OP_rand_get_params(fns);
 192             break;
 193         case OSSL_FUNC_RAND_GET_CTX_PARAMS:
 194             if (rand->get_ctx_params != NULL)
 195                 break;
 196             rand->get_ctx_params = OSSL_get_OP_rand_get_ctx_params(fns);
 197             break;
 198         case OSSL_FUNC_RAND_SET_CTX_PARAMS:
 199             if (rand->set_ctx_params != NULL)
 200                 break;
 201             rand->set_ctx_params = OSSL_get_OP_rand_set_ctx_params(fns);
 202             break;
 203         case OSSL_FUNC_RAND_VERIFY_ZEROIZATION:
 204             if (rand->verify_zeroization != NULL)
 205                 break;
 206             rand->verify_zeroization = OSSL_get_OP_rand_verify_zeroization(fns);
 207 #ifdef FIPS_MODULE
 208             fnzeroizecnt++;
 209 #endif
 210             break;
 211         }
 212     }
 213     /*
 214      * In order to be a consistent set of functions we must have at least
 215      * a complete set of "rand" functions and a complete set of context
 216      * management functions.  In FIPS mode, we also require the zeroization
 217      * verification function.
 218      *
 219      * In addition, if locking can be enabled, we need a complete set of
 220      * locking functions.
 221      */
 222     if (fnrandcnt != 3
 223             || fnctxcnt != 2
 224             || (fnlockcnt != 0 && fnlockcnt != 3)
 225 #ifdef FIPS_MODULE
 226             || fnzeroizecnt != 1
 227 #endif
 228        ) {
 229         evp_rand_free(rand);
 230         ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS);
 231         return NULL;
 232     }
 233
 234     if (prov != NULL && !ossl_provider_up_ref(prov)) {
 235         evp_rand_free(rand);
 236         ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
 237         return NULL;
 238     }
 239     rand->prov = prov;
 240
 241     return rand;
 242 }
 243
 244 EVP_RAND *EVP_RAND_fetch(OPENSSL_CTX *libctx, const char *algorithm,
 245                          const char *properties)
 246 {
 247     return evp_generic_fetch(libctx, OSSL_OP_RAND, algorithm, properties,
 248                              evp_rand_from_dispatch, evp_rand_up_ref,
 249                              evp_rand_free);
 250 }
 251
 252 int EVP_RAND_up_ref(EVP_RAND *rand)
 253 {
 254     return evp_rand_up_ref(rand);
 255 }
 256
 257 void EVP_RAND_free(EVP_RAND *rand)
 258 {
 259     evp_rand_free(rand);
 260 }
 261
 262 int EVP_RAND_number(const EVP_RAND *rand)
 263 {
 264     return rand->name_id;
 265 }
 266
 267 const char *EVP_RAND_name(const EVP_RAND *rand)
 268 {
 269     return evp_first_name(rand->prov, rand->name_id);
 270 }
 271
 272 int EVP_RAND_is_a(const EVP_RAND *rand, const char *name)
 273 {
 274     return evp_is_a(rand->prov, rand->name_id, NULL, name);
 275 }
 276
 277 const OSSL_PROVIDER *EVP_RAND_provider(const EVP_RAND *rand)
 278 {
 279     return rand->prov;
 280 }
 281
 282 int EVP_RAND_get_params(EVP_RAND *rand, OSSL_PARAM params[])
 283 {
 284     if (rand->get_params != NULL)
 285         return rand->get_params(params);
 286     return 1;
 287 }
 288
 289 EVP_RAND_CTX *EVP_RAND_CTX_new(EVP_RAND *rand, EVP_RAND_CTX *parent)
 290 {
 291     EVP_RAND_CTX *ctx;
 292     void *parent_ctx = NULL;
 293     const OSSL_DISPATCH *parent_dispatch = NULL;
 294
 295     if (rand == NULL) {
 296         EVPerr(0, EVP_R_INVALID_NULL_ALGORITHM);
 297         return NULL;
 298     }
 299
 300     ctx = OPENSSL_zalloc(sizeof(*ctx));
 301     if (ctx == NULL) {
 302         EVPerr(0, ERR_R_MALLOC_FAILURE);
 303         return NULL;
 304     }
 305     if (parent != NULL) {
 306         if (!EVP_RAND_enable_locking(parent)) {
 307             EVPerr(0, EVP_R_UNABLE_TO_ENABLE_PARENT_LOCKING);
 308             OPENSSL_free(ctx);
 309             return NULL;
 310         }
 311         parent_ctx = parent->data;
 312         parent_dispatch = parent->meth->dispatch;
 313     }
 314     if ((ctx->data = rand->newctx(ossl_provider_ctx(rand->prov), parent_ctx,
 315                                   parent_dispatch)) == NULL
 316             || !EVP_RAND_up_ref(rand)) {
 317         EVPerr(0, ERR_R_MALLOC_FAILURE);
 318         rand->freectx(ctx->data);
 319         OPENSSL_free(ctx);
 320         return NULL;
 321     }
 322     ctx->meth = rand;
 323     return ctx;
 324 }
 325
 326 void EVP_RAND_CTX_free(EVP_RAND_CTX *ctx)
 327 {
 328     if (ctx != NULL) {
 329         ctx->meth->freectx(ctx->data);
 330         ctx->data = NULL;
 331         EVP_RAND_free(ctx->meth);
 332         OPENSSL_free(ctx);
 333     }
 334 }
 335
 336 EVP_RAND *EVP_RAND_CTX_rand(EVP_RAND_CTX *ctx)
 337 {
 338     return ctx->meth;
 339 }
 340
 341 int EVP_RAND_get_ctx_params(EVP_RAND_CTX *ctx, OSSL_PARAM params[])
 342 {
 343     int res = 1;
 344
 345     if (ctx->meth->get_ctx_params != NULL) {
 346         if (!evp_rand_lock(ctx))
 347             return 0;
 348         res = ctx->meth->get_ctx_params(ctx->data, params);
 349         evp_rand_unlock(ctx);
 350     }
 351     return res;
 352 }
 353
 354 int EVP_RAND_set_ctx_params(EVP_RAND_CTX *ctx, const OSSL_PARAM params[])
 355 {
 356     int res = 1;
 357
 358     if (ctx->meth->set_ctx_params != NULL) {
 359         if (!evp_rand_lock(ctx))
 360             return 0;
 361         res = ctx->meth->set_ctx_params(ctx->data, params);
 362         evp_rand_unlock(ctx);
 363         /* Clear out the cache state because the values can change on a set */
 364         ctx->strength = 0;
 365         ctx->max_request = 0;
 366     }
 367     return res;
 368 }
 369
 370 const OSSL_PARAM *EVP_RAND_gettable_params(const EVP_RAND *rand)
 371 {
 372     return rand->gettable_params == NULL ? NULL : rand->gettable_params();
 373 }
 374
 375 const OSSL_PARAM *EVP_RAND_gettable_ctx_params(const EVP_RAND *rand)
 376 {
 377     return rand->gettable_ctx_params == NULL ? NULL
 378                                              : rand->gettable_ctx_params();
 379 }
 380
 381 const OSSL_PARAM *EVP_RAND_settable_ctx_params(const EVP_RAND *rand)
 382 {
 383     return rand->settable_ctx_params == NULL ? NULL
 384                                              :rand->settable_ctx_params();
 385 }
 386
 387 void EVP_RAND_do_all_provided(OPENSSL_CTX *libctx,
 388                               void (*fn)(EVP_RAND *rand, void *arg),
 389                               void *arg)
 390 {
 391     evp_generic_do_all(libctx, OSSL_OP_RAND,
 392                        (void (*)(void *, void *))fn, arg,
 393                        evp_rand_from_dispatch, evp_rand_free);
 394 }
 395
 396 void EVP_RAND_names_do_all(const EVP_RAND *rand,
 397                            void (*fn)(const char *name, void *data),
 398                            void *data)
 399 {
 400     if (rand->prov != NULL)
 401         evp_names_do_all(rand->prov, rand->name_id, fn, data);
 402 }
 403
 404 int EVP_RAND_instantiate(EVP_RAND_CTX *ctx, unsigned int strength,
 405                          int prediction_resistance,
 406                          const unsigned char *pstr, size_t pstr_len)
 407 {
 408     int res;
 409
 410     if (!evp_rand_lock(ctx))
 411         return 0;
 412     res = ctx->meth->instantiate(ctx->data, strength, prediction_resistance,
 413                                  pstr, pstr_len);
 414     evp_rand_unlock(ctx);
 415     return res;
 416 }
 417
 418 int EVP_RAND_uninstantiate(EVP_RAND_CTX *ctx)
 419 {
 420     int res;
 421
 422     if (!evp_rand_lock(ctx))
 423         return 0;
 424     res = ctx->meth->uninstantiate(ctx->data);
 425     evp_rand_unlock(ctx);
 426     return res;
 427 }
 428
 429 int EVP_RAND_generate(EVP_RAND_CTX *ctx, unsigned char *out, size_t outlen,
 430                       unsigned int strength, int prediction_resistance,
 431                       const unsigned char *addin, size_t addin_len)
 432 {
 433     size_t chunk;
 434     OSSL_PARAM params[2];
 435     int res = 0;
 436
 437     if (!evp_rand_lock(ctx))
 438         return 0;
 439     if (ctx->max_request == 0) {
 440         params[0] = OSSL_PARAM_construct_size_t(OSSL_DRBG_PARAM_MAX_REQUEST,
 441                                                 &chunk);
 442         params[1] = OSSL_PARAM_construct_end();
 443         if (!EVP_RAND_get_ctx_params(ctx, params) || chunk == 0) {
 444             EVPerr(0, EVP_R_UNABLE_TO_GET_MAXIMUM_REQUEST_SIZE);
 445             goto err;
 446         }
 447         ctx->max_request = chunk;
 448     }
 449     for (; outlen > 0; outlen -= chunk, out += chunk) {
 450         chunk = outlen > ctx->max_request ? ctx->max_request : outlen;
 451         if (!ctx->meth->generate(ctx->data, out, chunk, strength,
 452                                  prediction_resistance, addin, addin_len)) {
 453             EVPerr(0, EVP_R_GENERATE_ERROR);
 454             goto err;
 455         }
 456         /*
 457          * Prediction resistance is only relevant the first time around,
 458          * subsequently, the DRBG has already been properly reseeded.
 459          */
 460         prediction_resistance = 0;
 461     }
 462     res = 1;
 463 err:
 464     evp_rand_unlock(ctx);
 465     return res;
 466 }
 467
 468 int EVP_RAND_reseed(EVP_RAND_CTX *ctx, int prediction_resistance,
 469                     const unsigned char *ent, size_t ent_len,
 470                     const unsigned char *addin, size_t addin_len)
 471 {
 472     int res = 1;
 473
 474     if (!evp_rand_lock(ctx))
 475         return 0;
 476     if (ctx->meth->reseed != NULL)
 477         res = ctx->meth->reseed(ctx->data, prediction_resistance,
 478                                 ent, ent_len, addin, addin_len);
 479     evp_rand_unlock(ctx);
 480     return res;
 481 }
 482
 483 int EVP_RAND_nonce(EVP_RAND_CTX *ctx, unsigned char *out, size_t outlen)
 484 {
 485     int res = 1;
 486     unsigned int str = EVP_RAND_strength(ctx);
 487
 488     if (!evp_rand_lock(ctx))
 489         return 0;
 490     if (ctx->meth->nonce == NULL
 491             || !ctx->meth->nonce(ctx->data, out, str, outlen, outlen))
 492         res = ctx->meth->generate(ctx->data, out, outlen, str, 0, NULL, 0);
 493     evp_rand_unlock(ctx);
 494     return res;
 495 }
 496
 497 unsigned int EVP_RAND_strength(EVP_RAND_CTX *ctx)
 498 {
 499     OSSL_PARAM params[2];
 500     unsigned int t;
 501     int res;
 502
 503     if (ctx->strength == 0) {
 504         params[0] = OSSL_PARAM_construct_uint(OSSL_RAND_PARAM_STRENGTH, &t);
 505         params[1] = OSSL_PARAM_construct_end();
 506         if (!evp_rand_lock(ctx))
 507             return 0;
 508         res = EVP_RAND_get_ctx_params(ctx, params);
 509         evp_rand_unlock(ctx);
 510         if (!res)
 511             return 0;
 512         ctx->strength = t;
 513     }
 514     return ctx->strength;
 515 }
 516
 517 int EVP_RAND_state(EVP_RAND_CTX *ctx)
 518 {
 519     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
 520     int status, res;
 521
 522     params[0] = OSSL_PARAM_construct_int(OSSL_RAND_PARAM_STATE,
 523                                          &status);
 524     if (!evp_rand_lock(ctx))
 525         return 0;
 526     res = EVP_RAND_get_ctx_params(ctx, params);
 527     evp_rand_unlock(ctx);
 528     if (!res)
 529         status = EVP_RAND_STATE_ERROR;
 530     return status;
 531 }
 532
 533 int EVP_RAND_set_callbacks(EVP_RAND_CTX *ctx,
 534                            OSSL_INOUT_CALLBACK *get_entropy,
 535                            OSSL_CALLBACK *cleanup_entropy,
 536                            OSSL_INOUT_CALLBACK *get_nonce,
 537                            OSSL_CALLBACK *cleanup_nonce, void *arg)
 538 {
 539     if (ctx->meth->set_callbacks == NULL) {
 540         EVPerr(0, EVP_R_UNABLE_TO_SET_CALLBACKS);
 541         return 0;
 542     }
 543     ctx->meth->set_callbacks(ctx->data, get_entropy, cleanup_entropy,
 544                              get_nonce, cleanup_nonce, arg);
 545     return 1;
 546 }
 547
 548 int EVP_RAND_verify_zeroization(EVP_RAND_CTX *ctx)
 549 {
 550     int res = 0;
 551
 552     if (ctx->meth->verify_zeroization != NULL) {
 553         if (!evp_rand_lock(ctx))
 554             return 0;
 555         res = ctx->meth->verify_zeroization(ctx->data);
 556         evp_rand_unlock(ctx);
 557     }
 558     return res;
 559 }