crypto/rand/rand_lib.c

   1 /*
   2  * Copyright 1995-2021 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 /* We need to use some engine deprecated APIs */
  11 #define OPENSSL_SUPPRESS_DEPRECATED
  12
  13 #include <openssl/err.h>
  14 #include <openssl/opensslconf.h>
  15 #include <openssl/core_names.h>
  16 #include "internal/cryptlib.h"
  17 #include "internal/thread_once.h"
  18 #include "crypto/rand.h"
  19 #include "crypto/cryptlib.h"
  20 #include "rand_local.h"
  21
  22 #ifndef FIPS_MODULE
  23 # include <stdio.h>
  24 # include <time.h>
  25 # include <limits.h>
  26 # include <openssl/conf.h>
  27 # include <openssl/trace.h>
  28 # include <openssl/engine.h>
  29 # include "crypto/rand_pool.h"
  30 # include "prov/seeding.h"
  31 # include "internal/e_os.h"
  32
  33 # ifndef OPENSSL_NO_ENGINE
  34 /* non-NULL if default_RAND_meth is ENGINE-provided */
  35 static ENGINE *funct_ref;
  36 static CRYPTO_RWLOCK *rand_engine_lock;
  37 # endif
  38 # ifndef OPENSSL_NO_DEPRECATED_3_0
  39 static CRYPTO_RWLOCK *rand_meth_lock;
  40 static const RAND_METHOD *default_RAND_meth;
  41 # endif
  42 static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT;
  43
  44 static int rand_inited = 0;
  45
  46 DEFINE_RUN_ONCE_STATIC(do_rand_init)
  47 {
  48 # ifndef OPENSSL_NO_ENGINE
  49     rand_engine_lock = CRYPTO_THREAD_lock_new();
  50     if (rand_engine_lock == NULL)
  51         return 0;
  52 # endif
  53
  54 # ifndef OPENSSL_NO_DEPRECATED_3_0
  55     rand_meth_lock = CRYPTO_THREAD_lock_new();
  56     if (rand_meth_lock == NULL)
  57         goto err;
  58 # endif
  59
  60     if (!ossl_rand_pool_init())
  61         goto err;
  62
  63     rand_inited = 1;
  64     return 1;
  65
  66  err:
  67 # ifndef OPENSSL_NO_DEPRECATED_3_0
  68     CRYPTO_THREAD_lock_free(rand_meth_lock);
  69     rand_meth_lock = NULL;
  70 # endif
  71 # ifndef OPENSSL_NO_ENGINE
  72     CRYPTO_THREAD_lock_free(rand_engine_lock);
  73     rand_engine_lock = NULL;
  74 # endif
  75     return 0;
  76 }
  77
  78 void ossl_rand_cleanup_int(void)
  79 {
  80 # ifndef OPENSSL_NO_DEPRECATED_3_0
  81     const RAND_METHOD *meth = default_RAND_meth;
  82
  83     if (!rand_inited)
  84         return;
  85
  86     if (meth != NULL && meth->cleanup != NULL)
  87         meth->cleanup();
  88     RAND_set_rand_method(NULL);
  89 # endif
  90     ossl_rand_pool_cleanup();
  91 # ifndef OPENSSL_NO_ENGINE
  92     CRYPTO_THREAD_lock_free(rand_engine_lock);
  93     rand_engine_lock = NULL;
  94 # endif
  95 # ifndef OPENSSL_NO_DEPRECATED_3_0
  96     CRYPTO_THREAD_lock_free(rand_meth_lock);
  97     rand_meth_lock = NULL;
  98 # endif
  99     rand_inited = 0;
 100 }
 101
 102 /*
 103  * RAND_close_seed_files() ensures that any seed file descriptors are
 104  * closed after use.  This only applies to libcrypto/default provider,
 105  * it does not apply to other providers.
 106  */
 107 void RAND_keep_random_devices_open(int keep)
 108 {
 109     if (RUN_ONCE(&rand_init, do_rand_init))
 110         ossl_rand_pool_keep_random_devices_open(keep);
 111 }
 112
 113 /*
 114  * RAND_poll() reseeds the default RNG using random input
 115  *
 116  * The random input is obtained from polling various entropy
 117  * sources which depend on the operating system and are
 118  * configurable via the --with-rand-seed configure option.
 119  */
 120 int RAND_poll(void)
 121 {
 122 # ifndef OPENSSL_NO_DEPRECATED_3_0
 123     const RAND_METHOD *meth = RAND_get_rand_method();
 124     int ret = meth == RAND_OpenSSL();
 125
 126     if (meth == NULL)
 127         return 0;
 128
 129     if (!ret) {
 130         /* fill random pool and seed the current legacy RNG */
 131         RAND_POOL *pool = ossl_rand_pool_new(RAND_DRBG_STRENGTH, 1,
 132                                              (RAND_DRBG_STRENGTH + 7) / 8,
 133                                              RAND_POOL_MAX_LENGTH);
 134
 135         if (pool == NULL)
 136             return 0;
 137
 138         if (ossl_pool_acquire_entropy(pool) == 0)
 139             goto err;
 140
 141         if (meth->add == NULL
 142             || meth->add(ossl_rand_pool_buffer(pool),
 143                          ossl_rand_pool_length(pool),
 144                          (ossl_rand_pool_entropy(pool) / 8.0)) == 0)
 145             goto err;
 146
 147         ret = 1;
 148      err:
 149         ossl_rand_pool_free(pool);
 150     }
 151     return ret;
 152 # else
 153     static const char salt[] = "polling";
 154
 155     RAND_seed(salt, sizeof(salt));
 156     return 1;
 157 # endif
 158 }
 159
 160 # ifndef OPENSSL_NO_DEPRECATED_3_0
 161 static int rand_set_rand_method_internal(const RAND_METHOD *meth,
 162                                          ossl_unused ENGINE *e)
 163 {
 164     if (!RUN_ONCE(&rand_init, do_rand_init))
 165         return 0;
 166
 167     if (!CRYPTO_THREAD_write_lock(rand_meth_lock))
 168         return 0;
 169 #  ifndef OPENSSL_NO_ENGINE
 170     ENGINE_finish(funct_ref);
 171     funct_ref = e;
 172 #  endif
 173     default_RAND_meth = meth;
 174     CRYPTO_THREAD_unlock(rand_meth_lock);
 175     return 1;
 176 }
 177
 178 int RAND_set_rand_method(const RAND_METHOD *meth)
 179 {
 180     return rand_set_rand_method_internal(meth, NULL);
 181 }
 182
 183 const RAND_METHOD *RAND_get_rand_method(void)
 184 {
 185     const RAND_METHOD *tmp_meth = NULL;
 186
 187     if (!RUN_ONCE(&rand_init, do_rand_init))
 188         return NULL;
 189
 190     if (!CRYPTO_THREAD_write_lock(rand_meth_lock))
 191         return NULL;
 192     if (default_RAND_meth == NULL) {
 193 #  ifndef OPENSSL_NO_ENGINE
 194         ENGINE *e;
 195
 196         /* If we have an engine that can do RAND, use it. */
 197         if ((e = ENGINE_get_default_RAND()) != NULL
 198                 && (tmp_meth = ENGINE_get_RAND(e)) != NULL) {
 199             funct_ref = e;
 200             default_RAND_meth = tmp_meth;
 201         } else {
 202             ENGINE_finish(e);
 203             default_RAND_meth = &ossl_rand_meth;
 204         }
 205 #  else
 206         default_RAND_meth = &ossl_rand_meth;
 207 #  endif
 208     }
 209     tmp_meth = default_RAND_meth;
 210     CRYPTO_THREAD_unlock(rand_meth_lock);
 211     return tmp_meth;
 212 }
 213
 214 #  if !defined(OPENSSL_NO_ENGINE)
 215 int RAND_set_rand_engine(ENGINE *engine)
 216 {
 217     const RAND_METHOD *tmp_meth = NULL;
 218
 219     if (!RUN_ONCE(&rand_init, do_rand_init))
 220         return 0;
 221
 222     if (engine != NULL) {
 223         if (!ENGINE_init(engine))
 224             return 0;
 225         tmp_meth = ENGINE_get_RAND(engine);
 226         if (tmp_meth == NULL) {
 227             ENGINE_finish(engine);
 228             return 0;
 229         }
 230     }
 231     if (!CRYPTO_THREAD_write_lock(rand_engine_lock)) {
 232         ENGINE_finish(engine);
 233         return 0;
 234     }
 235
 236     /* This function releases any prior ENGINE so call it first */
 237     rand_set_rand_method_internal(tmp_meth, engine);
 238     CRYPTO_THREAD_unlock(rand_engine_lock);
 239     return 1;
 240 }
 241 #  endif
 242 # endif /* OPENSSL_NO_DEPRECATED_3_0 */
 243
 244 void RAND_seed(const void *buf, int num)
 245 {
 246     EVP_RAND_CTX *drbg;
 247 # ifndef OPENSSL_NO_DEPRECATED_3_0
 248     const RAND_METHOD *meth = RAND_get_rand_method();
 249
 250     if (meth != NULL && meth->seed != NULL) {
 251         meth->seed(buf, num);
 252         return;
 253     }
 254 # endif
 255
 256     drbg = RAND_get0_primary(NULL);
 257     if (drbg != NULL && num > 0)
 258         EVP_RAND_reseed(drbg, 0, NULL, 0, buf, num);
 259 }
 260
 261 void RAND_add(const void *buf, int num, double randomness)
 262 {
 263     EVP_RAND_CTX *drbg;
 264 # ifndef OPENSSL_NO_DEPRECATED_3_0
 265     const RAND_METHOD *meth = RAND_get_rand_method();
 266
 267     if (meth != NULL && meth->add != NULL) {
 268         meth->add(buf, num, randomness);
 269         return;
 270     }
 271 # endif
 272     drbg = RAND_get0_primary(NULL);
 273     if (drbg != NULL && num > 0)
 274         EVP_RAND_reseed(drbg, 0, NULL, 0, buf, num);
 275 }
 276
 277 # if !defined(OPENSSL_NO_DEPRECATED_1_1_0)
 278 int RAND_pseudo_bytes(unsigned char *buf, int num)
 279 {
 280     const RAND_METHOD *meth = RAND_get_rand_method();
 281
 282     if (meth != NULL && meth->pseudorand != NULL)
 283         return meth->pseudorand(buf, num);
 284     ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED);
 285     return -1;
 286 }
 287 # endif
 288
 289 int RAND_status(void)
 290 {
 291     EVP_RAND_CTX *rand;
 292 # ifndef OPENSSL_NO_DEPRECATED_3_0
 293     const RAND_METHOD *meth = RAND_get_rand_method();
 294
 295     if (meth != NULL && meth != RAND_OpenSSL())
 296         return meth->status != NULL ? meth->status() : 0;
 297 # endif
 298
 299     if ((rand = RAND_get0_primary(NULL)) == NULL)
 300         return 0;
 301     return EVP_RAND_get_state(rand) == EVP_RAND_STATE_READY;
 302 }
 303 # else  /* !FIPS_MODULE */
 304
 305 # ifndef OPENSSL_NO_DEPRECATED_3_0
 306 const RAND_METHOD *RAND_get_rand_method(void)
 307 {
 308     return NULL;
 309 }
 310 # endif
 311 #endif /* !FIPS_MODULE */
 312
 313 /*
 314  * This function is not part of RAND_METHOD, so if we're not using
 315  * the default method, then just call RAND_bytes().  Otherwise make
 316  * sure we're instantiated and use the private DRBG.
 317  */
 318 int RAND_priv_bytes_ex(OSSL_LIB_CTX *ctx, unsigned char *buf, size_t num,
 319                        unsigned int strength)
 320 {
 321     EVP_RAND_CTX *rand;
 322 #if !defined(OPENSSL_NO_DEPRECATED_3_0) && !defined(FIPS_MODULE)
 323     const RAND_METHOD *meth = RAND_get_rand_method();
 324
 325     if (meth != NULL && meth != RAND_OpenSSL()) {
 326         if (meth->bytes != NULL)
 327             return meth->bytes(buf, num);
 328         ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED);
 329         return -1;
 330     }
 331 #endif
 332
 333     rand = RAND_get0_private(ctx);
 334     if (rand != NULL)
 335         return EVP_RAND_generate(rand, buf, num, strength, 0, NULL, 0);
 336
 337     return 0;
 338 }
 339
 340 int RAND_priv_bytes(unsigned char *buf, int num)
 341 {
 342     if (num < 0)
 343         return 0;
 344     return RAND_priv_bytes_ex(NULL, buf, (size_t)num, 0);
 345 }
 346
 347 int RAND_bytes_ex(OSSL_LIB_CTX *ctx, unsigned char *buf, size_t num,
 348                   unsigned int strength)
 349 {
 350     EVP_RAND_CTX *rand;
 351 #if !defined(OPENSSL_NO_DEPRECATED_3_0) && !defined(FIPS_MODULE)
 352     const RAND_METHOD *meth = RAND_get_rand_method();
 353
 354     if (meth != NULL && meth != RAND_OpenSSL()) {
 355         if (meth->bytes != NULL)
 356             return meth->bytes(buf, num);
 357         ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED);
 358         return -1;
 359     }
 360 #endif
 361
 362     rand = RAND_get0_public(ctx);
 363     if (rand != NULL)
 364         return EVP_RAND_generate(rand, buf, num, strength, 0, NULL, 0);
 365
 366     return 0;
 367 }
 368
 369 int RAND_bytes(unsigned char *buf, int num)
 370 {
 371     if (num < 0)
 372         return 0;
 373     return RAND_bytes_ex(NULL, buf, (size_t)num, 0);
 374 }
 375
 376 typedef struct rand_global_st {
 377     /*
 378      * The three shared DRBG instances
 379      *
 380      * There are three shared DRBG instances: <primary>, <public>, and
 381      * <private>.  The <public> and <private> DRBGs are secondary ones.
 382      * These are used for non-secret (e.g. nonces) and secret
 383      * (e.g. private keys) data respectively.
 384      */
 385     CRYPTO_RWLOCK *lock;
 386
 387     EVP_RAND_CTX *seed;
 388
 389     /*
 390      * The <primary> DRBG
 391      *
 392      * Not used directly by the application, only for reseeding the two other
 393      * DRBGs. It reseeds itself by pulling either randomness from os entropy
 394      * sources or by consuming randomness which was added by RAND_add().
 395      *
 396      * The <primary> DRBG is a global instance which is accessed concurrently by
 397      * all threads. The necessary locking is managed automatically by its child
 398      * DRBG instances during reseeding.
 399      */
 400     EVP_RAND_CTX *primary;
 401
 402     /*
 403      * The <public> DRBG
 404      *
 405      * Used by default for generating random bytes using RAND_bytes().
 406      *
 407      * The <public> secondary DRBG is thread-local, i.e., there is one instance
 408      * per thread.
 409      */
 410     CRYPTO_THREAD_LOCAL public;
 411
 412     /*
 413      * The <private> DRBG
 414      *
 415      * Used by default for generating private keys using RAND_priv_bytes()
 416      *
 417      * The <private> secondary DRBG is thread-local, i.e., there is one
 418      * instance per thread.
 419      */
 420     CRYPTO_THREAD_LOCAL private;
 421
 422     /* Which RNG is being used by default and it's configuration settings */
 423     char *rng_name;
 424     char *rng_cipher;
 425     char *rng_digest;
 426     char *rng_propq;
 427
 428     /* Allow the randomness source to be changed */
 429     char *seed_name;
 430     char *seed_propq;
 431 } RAND_GLOBAL;
 432
 433 /*
 434  * Initialize the OSSL_LIB_CTX global DRBGs on first use.
 435  * Returns the allocated global data on success or NULL on failure.
 436  */
 437 static void *rand_ossl_ctx_new(OSSL_LIB_CTX *libctx)
 438 {
 439     RAND_GLOBAL *dgbl = OPENSSL_zalloc(sizeof(*dgbl));
 440
 441     if (dgbl == NULL)
 442         return NULL;
 443
 444 #ifndef FIPS_MODULE
 445     /*
 446      * We need to ensure that base libcrypto thread handling has been
 447      * initialised.
 448      */
 449      OPENSSL_init_crypto(OPENSSL_INIT_BASE_ONLY, NULL);
 450 #endif
 451
 452     dgbl->lock = CRYPTO_THREAD_lock_new();
 453     if (dgbl->lock == NULL)
 454         goto err1;
 455
 456     if (!CRYPTO_THREAD_init_local(&dgbl->private, NULL))
 457         goto err1;
 458
 459     if (!CRYPTO_THREAD_init_local(&dgbl->public, NULL))
 460         goto err2;
 461
 462     return dgbl;
 463
 464  err2:
 465     CRYPTO_THREAD_cleanup_local(&dgbl->private);
 466  err1:
 467     CRYPTO_THREAD_lock_free(dgbl->lock);
 468     OPENSSL_free(dgbl);
 469     return NULL;
 470 }
 471
 472 static void rand_ossl_ctx_free(void *vdgbl)
 473 {
 474     RAND_GLOBAL *dgbl = vdgbl;
 475
 476     if (dgbl == NULL)
 477         return;
 478
 479     CRYPTO_THREAD_lock_free(dgbl->lock);
 480     CRYPTO_THREAD_cleanup_local(&dgbl->private);
 481     CRYPTO_THREAD_cleanup_local(&dgbl->public);
 482     EVP_RAND_CTX_free(dgbl->primary);
 483     EVP_RAND_CTX_free(dgbl->seed);
 484     OPENSSL_free(dgbl->rng_name);
 485     OPENSSL_free(dgbl->rng_cipher);
 486     OPENSSL_free(dgbl->rng_digest);
 487     OPENSSL_free(dgbl->rng_propq);
 488     OPENSSL_free(dgbl->seed_name);
 489     OPENSSL_free(dgbl->seed_propq);
 490
 491     OPENSSL_free(dgbl);
 492 }
 493
 494 static const OSSL_LIB_CTX_METHOD rand_drbg_ossl_ctx_method = {
 495     OSSL_LIB_CTX_METHOD_PRIORITY_2,
 496     rand_ossl_ctx_new,
 497     rand_ossl_ctx_free,
 498 };
 499
 500 static RAND_GLOBAL *rand_get_global(OSSL_LIB_CTX *libctx)
 501 {
 502     return ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_DRBG_INDEX,
 503                                  &rand_drbg_ossl_ctx_method);
 504 }
 505
 506 static void rand_delete_thread_state(void *arg)
 507 {
 508     OSSL_LIB_CTX *ctx = arg;
 509     RAND_GLOBAL *dgbl = rand_get_global(ctx);
 510     EVP_RAND_CTX *rand;
 511
 512     if (dgbl == NULL)
 513         return;
 514
 515     rand = CRYPTO_THREAD_get_local(&dgbl->public);
 516     CRYPTO_THREAD_set_local(&dgbl->public, NULL);
 517     EVP_RAND_CTX_free(rand);
 518
 519     rand = CRYPTO_THREAD_get_local(&dgbl->private);
 520     CRYPTO_THREAD_set_local(&dgbl->private, NULL);
 521     EVP_RAND_CTX_free(rand);
 522 }
 523
 524 #ifndef FIPS_MODULE
 525 static EVP_RAND_CTX *rand_new_seed(OSSL_LIB_CTX *libctx)
 526 {
 527     EVP_RAND *rand;
 528     RAND_GLOBAL *dgbl = rand_get_global(libctx);
 529     EVP_RAND_CTX *ctx;
 530     char *name;
 531
 532     name = dgbl->seed_name != NULL ? dgbl->seed_name : "SEED-SRC";
 533     rand = EVP_RAND_fetch(libctx, name, dgbl->seed_propq);
 534     if (rand == NULL) {
 535         ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_FETCH_DRBG);
 536         return NULL;
 537     }
 538     ctx = EVP_RAND_CTX_new(rand, NULL);
 539     EVP_RAND_free(rand);
 540     if (ctx == NULL) {
 541         ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_CREATE_DRBG);
 542         return NULL;
 543     }
 544     if (!EVP_RAND_instantiate(ctx, 0, 0, NULL, 0, NULL)) {
 545         ERR_raise(ERR_LIB_RAND, RAND_R_ERROR_INSTANTIATING_DRBG);
 546         EVP_RAND_CTX_free(ctx);
 547         return NULL;
 548     }
 549     return ctx;
 550 }
 551 #endif
 552
 553 static EVP_RAND_CTX *rand_new_drbg(OSSL_LIB_CTX *libctx, EVP_RAND_CTX *parent,
 554                                    unsigned int reseed_interval,
 555                                    time_t reseed_time_interval, int use_df)
 556 {
 557     EVP_RAND *rand;
 558     RAND_GLOBAL *dgbl = rand_get_global(libctx);
 559     EVP_RAND_CTX *ctx;
 560     OSSL_PARAM params[8], *p = params;
 561     const OSSL_PARAM *settables;
 562     char *name, *cipher;
 563
 564     name = dgbl->rng_name != NULL ? dgbl->rng_name : "CTR-DRBG";
 565     rand = EVP_RAND_fetch(libctx, name, dgbl->rng_propq);
 566     if (rand == NULL) {
 567         ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_FETCH_DRBG);
 568         return NULL;
 569     }
 570     ctx = EVP_RAND_CTX_new(rand, parent);
 571     EVP_RAND_free(rand);
 572     if (ctx == NULL) {
 573         ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_CREATE_DRBG);
 574         return NULL;
 575     }
 576
 577     settables = EVP_RAND_CTX_settable_params(ctx);
 578     if (OSSL_PARAM_locate_const(settables, OSSL_DRBG_PARAM_CIPHER)) {
 579         cipher = dgbl->rng_cipher != NULL ? dgbl->rng_cipher : "AES-256-CTR";
 580         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_CIPHER,
 581                                                 cipher, 0);
 582     }
 583     if (dgbl->rng_digest != NULL
 584             && OSSL_PARAM_locate_const(settables, OSSL_DRBG_PARAM_DIGEST))
 585         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_DIGEST,
 586                                                 dgbl->rng_digest, 0);
 587     if (dgbl->rng_propq != NULL)
 588         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_PROPERTIES,
 589                                                 dgbl->rng_propq, 0);
 590     if (OSSL_PARAM_locate_const(settables, OSSL_ALG_PARAM_MAC))
 591         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_MAC, "HMAC", 0);
 592     if (OSSL_PARAM_locate_const(settables, OSSL_DRBG_PARAM_USE_DF))
 593         *p++ = OSSL_PARAM_construct_int(OSSL_DRBG_PARAM_USE_DF, &use_df);
 594     *p++ = OSSL_PARAM_construct_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS,
 595                                      &reseed_interval);
 596     *p++ = OSSL_PARAM_construct_time_t(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL,
 597                                        &reseed_time_interval);
 598     *p = OSSL_PARAM_construct_end();
 599     if (!EVP_RAND_instantiate(ctx, 0, 0, NULL, 0, params)) {
 600         ERR_raise(ERR_LIB_RAND, RAND_R_ERROR_INSTANTIATING_DRBG);
 601         EVP_RAND_CTX_free(ctx);
 602         return NULL;
 603     }
 604     return ctx;
 605 }
 606
 607 /*
 608  * Get the primary random generator.
 609  * Returns pointer to its EVP_RAND_CTX on success, NULL on failure.
 610  *
 611  */
 612 EVP_RAND_CTX *RAND_get0_primary(OSSL_LIB_CTX *ctx)
 613 {
 614     RAND_GLOBAL *dgbl = rand_get_global(ctx);
 615     EVP_RAND_CTX *ret;
 616
 617     if (dgbl == NULL)
 618         return NULL;
 619
 620     if (!CRYPTO_THREAD_read_lock(dgbl->lock))
 621         return NULL;
 622
 623     ret = dgbl->primary;
 624     CRYPTO_THREAD_unlock(dgbl->lock);
 625
 626     if (ret != NULL)
 627         return ret;
 628
 629     if (!CRYPTO_THREAD_write_lock(dgbl->lock))
 630         return NULL;
 631
 632     ret = dgbl->primary;
 633     if (ret != NULL) {
 634         CRYPTO_THREAD_unlock(dgbl->lock);
 635         return ret;
 636     }
 637
 638 #ifndef FIPS_MODULE
 639     if (dgbl->seed == NULL) {
 640         ERR_set_mark();
 641         dgbl->seed = rand_new_seed(ctx);
 642         ERR_pop_to_mark();
 643     }
 644 #endif
 645
 646     ret = dgbl->primary = rand_new_drbg(ctx, dgbl->seed,
 647                                         PRIMARY_RESEED_INTERVAL,
 648                                         PRIMARY_RESEED_TIME_INTERVAL, 1);
 649     /*
 650     * The primary DRBG may be shared between multiple threads so we must
 651     * enable locking.
 652     */
 653     if (ret != NULL && !EVP_RAND_enable_locking(ret)) {
 654         ERR_raise(ERR_LIB_EVP, EVP_R_UNABLE_TO_ENABLE_LOCKING);
 655         EVP_RAND_CTX_free(ret);
 656         ret = dgbl->primary = NULL;
 657     }
 658     CRYPTO_THREAD_unlock(dgbl->lock);
 659
 660     return ret;
 661 }
 662
 663 /*
 664  * Get the public random generator.
 665  * Returns pointer to its EVP_RAND_CTX on success, NULL on failure.
 666  */
 667 EVP_RAND_CTX *RAND_get0_public(OSSL_LIB_CTX *ctx)
 668 {
 669     RAND_GLOBAL *dgbl = rand_get_global(ctx);
 670     EVP_RAND_CTX *rand, *primary;
 671
 672     if (dgbl == NULL)
 673         return NULL;
 674
 675     rand = CRYPTO_THREAD_get_local(&dgbl->public);
 676     if (rand == NULL) {
 677         primary = RAND_get0_primary(ctx);
 678         if (primary == NULL)
 679             return NULL;
 680
 681         ctx = ossl_lib_ctx_get_concrete(ctx);
 682         /*
 683          * If the private is also NULL then this is the first time we've
 684          * used this thread.
 685          */
 686         if (CRYPTO_THREAD_get_local(&dgbl->private) == NULL
 687                 && !ossl_init_thread_start(NULL, ctx, rand_delete_thread_state))
 688             return NULL;
 689         rand = rand_new_drbg(ctx, primary, SECONDARY_RESEED_INTERVAL,
 690                              SECONDARY_RESEED_TIME_INTERVAL, 0);
 691         CRYPTO_THREAD_set_local(&dgbl->public, rand);
 692     }
 693     return rand;
 694 }
 695
 696 /*
 697  * Get the private random generator.
 698  * Returns pointer to its EVP_RAND_CTX on success, NULL on failure.
 699  */
 700 EVP_RAND_CTX *RAND_get0_private(OSSL_LIB_CTX *ctx)
 701 {
 702     RAND_GLOBAL *dgbl = rand_get_global(ctx);
 703     EVP_RAND_CTX *rand, *primary;
 704
 705     if (dgbl == NULL)
 706         return NULL;
 707
 708     rand = CRYPTO_THREAD_get_local(&dgbl->private);
 709     if (rand == NULL) {
 710         primary = RAND_get0_primary(ctx);
 711         if (primary == NULL)
 712             return NULL;
 713
 714         ctx = ossl_lib_ctx_get_concrete(ctx);
 715         /*
 716          * If the public is also NULL then this is the first time we've
 717          * used this thread.
 718          */
 719         if (CRYPTO_THREAD_get_local(&dgbl->public) == NULL
 720                 && !ossl_init_thread_start(NULL, ctx, rand_delete_thread_state))
 721             return NULL;
 722         rand = rand_new_drbg(ctx, primary, SECONDARY_RESEED_INTERVAL,
 723                              SECONDARY_RESEED_TIME_INTERVAL, 0);
 724         CRYPTO_THREAD_set_local(&dgbl->private, rand);
 725     }
 726     return rand;
 727 }
 728
 729 #ifndef FIPS_MODULE
 730 static int random_set_string(char **p, const char *s)
 731 {
 732     char *d = NULL;
 733
 734     if (s != NULL) {
 735         d = OPENSSL_strdup(s);
 736         if (d == NULL) {
 737             ERR_raise(ERR_LIB_CRYPTO, ERR_R_MALLOC_FAILURE);
 738             return 0;
 739         }
 740     }
 741     OPENSSL_free(*p);
 742     *p = d;
 743     return 1;
 744 }
 745
 746 /*
 747  * Load the DRBG definitions from a configuration file.
 748  */
 749 static int random_conf_init(CONF_IMODULE *md, const CONF *cnf)
 750 {
 751     STACK_OF(CONF_VALUE) *elist;
 752     CONF_VALUE *cval;
 753     RAND_GLOBAL *dgbl = rand_get_global(NCONF_get0_libctx((CONF *)cnf));
 754     int i, r = 1;
 755
 756     OSSL_TRACE1(CONF, "Loading random module: section %s\n",
 757                 CONF_imodule_get_value(md));
 758
 759     /* Value is a section containing RANDOM configuration */
 760     elist = NCONF_get_section(cnf, CONF_imodule_get_value(md));
 761     if (elist == NULL) {
 762         ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_RANDOM_SECTION_ERROR);
 763         return 0;
 764     }
 765
 766     for (i = 0; i < sk_CONF_VALUE_num(elist); i++) {
 767         cval = sk_CONF_VALUE_value(elist, i);
 768         if (strcasecmp(cval->name, "random") == 0) {
 769             if (!random_set_string(&dgbl->rng_name, cval->value))
 770                 return 0;
 771         } else if (strcasecmp(cval->name, "cipher") == 0) {
 772             if (!random_set_string(&dgbl->rng_cipher, cval->value))
 773                 return 0;
 774         } else if (strcasecmp(cval->name, "digest") == 0) {
 775             if (!random_set_string(&dgbl->rng_digest, cval->value))
 776                 return 0;
 777         } else if (strcasecmp(cval->name, "properties") == 0) {
 778             if (!random_set_string(&dgbl->rng_propq, cval->value))
 779                 return 0;
 780         } else if (strcasecmp(cval->name, "seed") == 0) {
 781             if (!random_set_string(&dgbl->seed_name, cval->value))
 782                 return 0;
 783         } else if (strcasecmp(cval->name, "seed_properties") == 0) {
 784             if (!random_set_string(&dgbl->seed_propq, cval->value))
 785                 return 0;
 786         } else {
 787             ERR_raise_data(ERR_LIB_CRYPTO,
 788                            CRYPTO_R_UNKNOWN_NAME_IN_RANDOM_SECTION,
 789                            "name=%s, value=%s", cval->name, cval->value);
 790             r = 0;
 791         }
 792     }
 793     return r;
 794 }
 795
 796
 797 static void random_conf_deinit(CONF_IMODULE *md)
 798 {
 799     OSSL_TRACE(CONF, "Cleaned up random\n");
 800 }
 801
 802 void ossl_random_add_conf_module(void)
 803 {
 804     OSSL_TRACE(CONF, "Adding config module 'random'\n");
 805     CONF_module_add("random", random_conf_init, random_conf_deinit);
 806 }
 807
 808 int RAND_set_DRBG_type(OSSL_LIB_CTX *ctx, const char *drbg, const char *propq,
 809                        const char *cipher, const char *digest)
 810 {
 811     RAND_GLOBAL *dgbl = rand_get_global(ctx);
 812
 813     if (dgbl == NULL)
 814         return 0;
 815     if (dgbl->primary != NULL) {
 816         ERR_raise(ERR_LIB_CRYPTO, RAND_R_ALREADY_INSTANTIATED);
 817         return 0;
 818     }
 819     return random_set_string(&dgbl->rng_name, drbg)
 820         && random_set_string(&dgbl->rng_propq, propq)
 821         && random_set_string(&dgbl->rng_cipher, cipher)
 822         && random_set_string(&dgbl->rng_digest, digest);
 823 }
 824
 825 int RAND_set_seed_source_type(OSSL_LIB_CTX *ctx, const char *seed,
 826                               const char *propq)
 827 {
 828     RAND_GLOBAL *dgbl = rand_get_global(ctx);
 829
 830     if (dgbl == NULL)
 831         return 0;
 832     if (dgbl->primary != NULL) {
 833         ERR_raise(ERR_LIB_CRYPTO, RAND_R_ALREADY_INSTANTIATED);
 834         return 0;
 835     }
 836     return random_set_string(&dgbl->seed_name, seed)
 837         && random_set_string(&dgbl->seed_propq, propq);
 838 }
 839
 840 #endif