2 * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
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
10 /* We need to use some engine deprecated APIs */
11 #define OPENSSL_SUPPRESS_DEPRECATED
16 #include <openssl/trace.h>
17 #include <openssl/err.h>
18 #include <openssl/conf.h>
19 #include "internal/cryptlib.h"
20 #include <openssl/opensslconf.h>
21 #include "crypto/rand.h"
22 #include "crypto/cryptlib.h"
23 #include <openssl/engine.h>
24 #include <openssl/core_names.h>
25 #include "internal/thread_once.h"
26 #include "rand_local.h"
30 # include "crypto/rand_pool.h"
31 # include "prov/seeding.h"
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;
38 # ifndef OPENSSL_NO_DEPRECATED_3_0
39 static CRYPTO_RWLOCK *rand_meth_lock;
40 static const RAND_METHOD *default_RAND_meth;
42 static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT;
44 static int rand_inited = 0;
46 DEFINE_RUN_ONCE_STATIC(do_rand_init)
48 # ifndef OPENSSL_NO_ENGINE
49 rand_engine_lock = CRYPTO_THREAD_lock_new();
50 if (rand_engine_lock == NULL)
54 # ifndef OPENSSL_NO_DEPRECATED_3_0
55 rand_meth_lock = CRYPTO_THREAD_lock_new();
56 if (rand_meth_lock == NULL)
60 if (!ossl_rand_pool_init())
67 # ifndef OPENSSL_NO_DEPRECATED_3_0
68 CRYPTO_THREAD_lock_free(rand_meth_lock);
69 rand_meth_lock = NULL;
71 # ifndef OPENSSL_NO_ENGINE
72 CRYPTO_THREAD_lock_free(rand_engine_lock);
73 rand_engine_lock = NULL;
78 void ossl_rand_cleanup_int(void)
80 # ifndef OPENSSL_NO_DEPRECATED_3_0
81 const RAND_METHOD *meth = default_RAND_meth;
86 if (meth != NULL && meth->cleanup != NULL)
88 RAND_set_rand_method(NULL);
90 ossl_rand_pool_cleanup();
91 # ifndef OPENSSL_NO_ENGINE
92 CRYPTO_THREAD_lock_free(rand_engine_lock);
93 rand_engine_lock = NULL;
95 # ifndef OPENSSL_NO_DEPRECATED_3_0
96 CRYPTO_THREAD_lock_free(rand_meth_lock);
97 rand_meth_lock = NULL;
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.
107 void RAND_keep_random_devices_open(int keep)
109 if (RUN_ONCE(&rand_init, do_rand_init))
110 ossl_rand_pool_keep_random_devices_open(keep);
114 * RAND_poll() reseeds the default RNG using random input
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.
122 # ifndef OPENSSL_NO_DEPRECATED_3_0
123 const RAND_METHOD *meth = RAND_get_rand_method();
124 int ret = meth == RAND_OpenSSL();
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);
138 if (ossl_pool_acquire_entropy(pool) == 0)
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)
149 ossl_rand_pool_free(pool);
153 static const char salt[] = "polling";
155 RAND_seed(salt, sizeof(salt));
160 # ifndef OPENSSL_NO_DEPRECATED_3_0
161 static int rand_set_rand_method_internal(const RAND_METHOD *meth,
162 ossl_unused ENGINE *e)
164 if (!RUN_ONCE(&rand_init, do_rand_init))
167 if (!CRYPTO_THREAD_write_lock(rand_meth_lock))
169 # ifndef OPENSSL_NO_ENGINE
170 ENGINE_finish(funct_ref);
173 default_RAND_meth = meth;
174 CRYPTO_THREAD_unlock(rand_meth_lock);
178 int RAND_set_rand_method(const RAND_METHOD *meth)
180 return rand_set_rand_method_internal(meth, NULL);
183 const RAND_METHOD *RAND_get_rand_method(void)
185 const RAND_METHOD *tmp_meth = NULL;
187 if (!RUN_ONCE(&rand_init, do_rand_init))
190 if (!CRYPTO_THREAD_write_lock(rand_meth_lock))
192 if (default_RAND_meth == NULL) {
193 # ifndef OPENSSL_NO_ENGINE
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) {
200 default_RAND_meth = tmp_meth;
203 default_RAND_meth = &ossl_rand_meth;
206 default_RAND_meth = &ossl_rand_meth;
209 tmp_meth = default_RAND_meth;
210 CRYPTO_THREAD_unlock(rand_meth_lock);
214 # if !defined(OPENSSL_NO_ENGINE)
215 int RAND_set_rand_engine(ENGINE *engine)
217 const RAND_METHOD *tmp_meth = NULL;
219 if (!RUN_ONCE(&rand_init, do_rand_init))
222 if (engine != NULL) {
223 if (!ENGINE_init(engine))
225 tmp_meth = ENGINE_get_RAND(engine);
226 if (tmp_meth == NULL) {
227 ENGINE_finish(engine);
231 if (!CRYPTO_THREAD_write_lock(rand_engine_lock)) {
232 ENGINE_finish(engine);
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);
242 # endif /* OPENSSL_NO_DEPRECATED_3_0 */
244 void RAND_seed(const void *buf, int num)
247 # ifndef OPENSSL_NO_DEPRECATED_3_0
248 const RAND_METHOD *meth = RAND_get_rand_method();
250 if (meth != NULL && meth->seed != NULL) {
251 meth->seed(buf, num);
256 drbg = RAND_get0_primary(NULL);
257 if (drbg != NULL && num > 0)
258 EVP_RAND_reseed(drbg, 0, NULL, 0, buf, num);
261 void RAND_add(const void *buf, int num, double randomness)
264 # ifndef OPENSSL_NO_DEPRECATED_3_0
265 const RAND_METHOD *meth = RAND_get_rand_method();
267 if (meth != NULL && meth->add != NULL) {
268 meth->add(buf, num, randomness);
272 drbg = RAND_get0_primary(NULL);
273 if (drbg != NULL && num > 0)
274 EVP_RAND_reseed(drbg, 0, NULL, 0, buf, num);
277 # if !defined(OPENSSL_NO_DEPRECATED_1_1_0)
278 int RAND_pseudo_bytes(unsigned char *buf, int num)
280 const RAND_METHOD *meth = RAND_get_rand_method();
282 if (meth != NULL && meth->pseudorand != NULL)
283 return meth->pseudorand(buf, num);
284 ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED);
289 int RAND_status(void)
292 # ifndef OPENSSL_NO_DEPRECATED_3_0
293 const RAND_METHOD *meth = RAND_get_rand_method();
295 if (meth != NULL && meth != RAND_OpenSSL())
296 return meth->status != NULL ? meth->status() : 0;
299 if ((rand = RAND_get0_primary(NULL)) == NULL)
301 return EVP_RAND_state(rand) == EVP_RAND_STATE_READY;
303 # else /* !FIPS_MODULE */
305 # ifndef OPENSSL_NO_DEPRECATED_3_0
306 const RAND_METHOD *RAND_get_rand_method(void)
311 #endif /* !FIPS_MODULE */
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.
318 int RAND_priv_bytes_ex(OSSL_LIB_CTX *ctx, unsigned char *buf, int num,
319 unsigned int strength)
322 #ifndef OPENSSL_NO_DEPRECATED_3_0
323 const RAND_METHOD *meth = RAND_get_rand_method();
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);
333 rand = RAND_get0_private(ctx);
335 return EVP_RAND_generate(rand, buf, num, strength, 0, NULL, 0);
340 int RAND_priv_bytes(unsigned char *buf, int num)
342 return RAND_priv_bytes_ex(NULL, buf, num, 0);
345 int RAND_bytes_ex(OSSL_LIB_CTX *ctx, unsigned char *buf, int num,
346 unsigned int strength)
349 #ifndef OPENSSL_NO_DEPRECATED_3_0
350 const RAND_METHOD *meth = RAND_get_rand_method();
352 if (meth != NULL && meth != RAND_OpenSSL()) {
353 if (meth->bytes != NULL)
354 return meth->bytes(buf, num);
355 ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED);
360 rand = RAND_get0_public(ctx);
362 return EVP_RAND_generate(rand, buf, num, strength, 0, NULL, 0);
367 int RAND_bytes(unsigned char *buf, int num)
369 return RAND_bytes_ex(NULL, buf, num, 0);
372 typedef struct rand_global_st {
374 * The three shared DRBG instances
376 * There are three shared DRBG instances: <primary>, <public>, and
377 * <private>. The <public> and <private> DRBGs are secondary ones.
378 * These are used for non-secret (e.g. nonces) and secret
379 * (e.g. private keys) data respectively.
388 * Not used directly by the application, only for reseeding the two other
389 * DRBGs. It reseeds itself by pulling either randomness from os entropy
390 * sources or by consuming randomness which was added by RAND_add().
392 * The <primary> DRBG is a global instance which is accessed concurrently by
393 * all threads. The necessary locking is managed automatically by its child
394 * DRBG instances during reseeding.
396 EVP_RAND_CTX *primary;
401 * Used by default for generating random bytes using RAND_bytes().
403 * The <public> secondary DRBG is thread-local, i.e., there is one instance
406 CRYPTO_THREAD_LOCAL public;
411 * Used by default for generating private keys using RAND_priv_bytes()
413 * The <private> secondary DRBG is thread-local, i.e., there is one
414 * instance per thread.
416 CRYPTO_THREAD_LOCAL private;
418 /* Which RNG is being used by default and it's configuration settings */
424 /* Allow the randomness source to be changed */
430 * Initialize the OSSL_LIB_CTX global DRBGs on first use.
431 * Returns the allocated global data on success or NULL on failure.
433 static void *rand_ossl_ctx_new(OSSL_LIB_CTX *libctx)
435 RAND_GLOBAL *dgbl = OPENSSL_zalloc(sizeof(*dgbl));
442 * We need to ensure that base libcrypto thread handling has been
445 OPENSSL_init_crypto(OPENSSL_INIT_BASE_ONLY, NULL);
448 dgbl->lock = CRYPTO_THREAD_lock_new();
449 if (dgbl->lock == NULL)
452 if (!CRYPTO_THREAD_init_local(&dgbl->private, NULL))
455 if (!CRYPTO_THREAD_init_local(&dgbl->public, NULL))
461 CRYPTO_THREAD_cleanup_local(&dgbl->private);
463 CRYPTO_THREAD_lock_free(dgbl->lock);
468 static void rand_ossl_ctx_free(void *vdgbl)
470 RAND_GLOBAL *dgbl = vdgbl;
475 CRYPTO_THREAD_lock_free(dgbl->lock);
476 CRYPTO_THREAD_cleanup_local(&dgbl->private);
477 CRYPTO_THREAD_cleanup_local(&dgbl->public);
478 EVP_RAND_CTX_free(dgbl->primary);
479 EVP_RAND_CTX_free(dgbl->seed);
480 OPENSSL_free(dgbl->rng_name);
481 OPENSSL_free(dgbl->rng_cipher);
482 OPENSSL_free(dgbl->rng_digest);
483 OPENSSL_free(dgbl->rng_propq);
484 OPENSSL_free(dgbl->seed_name);
485 OPENSSL_free(dgbl->seed_propq);
490 static const OSSL_LIB_CTX_METHOD rand_drbg_ossl_ctx_method = {
491 OSSL_LIB_CTX_METHOD_DEFAULT_PRIORITY,
496 static RAND_GLOBAL *rand_get_global(OSSL_LIB_CTX *libctx)
498 return ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_DRBG_INDEX,
499 &rand_drbg_ossl_ctx_method);
502 static void rand_delete_thread_state(void *arg)
504 OSSL_LIB_CTX *ctx = arg;
505 RAND_GLOBAL *dgbl = rand_get_global(ctx);
511 rand = CRYPTO_THREAD_get_local(&dgbl->public);
512 CRYPTO_THREAD_set_local(&dgbl->public, NULL);
513 EVP_RAND_CTX_free(rand);
515 rand = CRYPTO_THREAD_get_local(&dgbl->private);
516 CRYPTO_THREAD_set_local(&dgbl->private, NULL);
517 EVP_RAND_CTX_free(rand);
521 static EVP_RAND_CTX *rand_new_seed(OSSL_LIB_CTX *libctx)
524 RAND_GLOBAL *dgbl = rand_get_global(libctx);
528 name = dgbl->seed_name != NULL ? dgbl->seed_name : "SEED-SRC";
529 rand = EVP_RAND_fetch(libctx, name, dgbl->seed_propq);
531 ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_FETCH_DRBG);
534 ctx = EVP_RAND_CTX_new(rand, NULL);
537 ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_CREATE_DRBG);
540 if (!EVP_RAND_instantiate(ctx, 0, 0, NULL, 0, NULL)) {
541 ERR_raise(ERR_LIB_RAND, RAND_R_ERROR_INSTANTIATING_DRBG);
542 EVP_RAND_CTX_free(ctx);
549 static EVP_RAND_CTX *rand_new_drbg(OSSL_LIB_CTX *libctx, EVP_RAND_CTX *parent,
550 unsigned int reseed_interval,
551 time_t reseed_time_interval)
554 RAND_GLOBAL *dgbl = rand_get_global(libctx);
556 OSSL_PARAM params[7], *p = params;
559 name = dgbl->rng_name != NULL ? dgbl->rng_name : "CTR-DRBG";
560 rand = EVP_RAND_fetch(libctx, name, dgbl->rng_propq);
562 ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_FETCH_DRBG);
565 ctx = EVP_RAND_CTX_new(rand, parent);
568 ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_CREATE_DRBG);
573 * Rather than trying to decode the DRBG settings, just pass them through
574 * and rely on the other end to ignore those it doesn't care about.
576 cipher = dgbl->rng_cipher != NULL ? dgbl->rng_cipher : "AES-256-CTR";
577 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_CIPHER,
579 if (dgbl->rng_digest != NULL)
580 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_DIGEST,
581 dgbl->rng_digest, 0);
582 if (dgbl->rng_propq != NULL)
583 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_PROPERTIES,
585 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_MAC, "HMAC", 0);
586 *p++ = OSSL_PARAM_construct_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS,
588 *p++ = OSSL_PARAM_construct_time_t(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL,
589 &reseed_time_interval);
590 *p = OSSL_PARAM_construct_end();
591 if (!EVP_RAND_instantiate(ctx, 0, 0, NULL, 0, params)) {
592 ERR_raise(ERR_LIB_RAND, RAND_R_ERROR_INSTANTIATING_DRBG);
593 EVP_RAND_CTX_free(ctx);
600 * Get the primary random generator.
601 * Returns pointer to its EVP_RAND_CTX on success, NULL on failure.
604 EVP_RAND_CTX *RAND_get0_primary(OSSL_LIB_CTX *ctx)
606 RAND_GLOBAL *dgbl = rand_get_global(ctx);
612 if (!CRYPTO_THREAD_read_lock(dgbl->lock))
616 CRYPTO_THREAD_unlock(dgbl->lock);
621 if (!CRYPTO_THREAD_write_lock(dgbl->lock))
626 CRYPTO_THREAD_unlock(dgbl->lock);
631 if (dgbl->seed == NULL) {
633 dgbl->seed = rand_new_seed(ctx);
638 ret = dgbl->primary = rand_new_drbg(ctx, dgbl->seed,
639 PRIMARY_RESEED_INTERVAL,
640 PRIMARY_RESEED_TIME_INTERVAL);
642 * The primary DRBG may be shared between multiple threads so we must
645 if (ret != NULL && !EVP_RAND_enable_locking(ret)) {
646 ERR_raise(ERR_LIB_EVP, EVP_R_UNABLE_TO_ENABLE_LOCKING);
647 EVP_RAND_CTX_free(ret);
648 ret = dgbl->primary = NULL;
650 CRYPTO_THREAD_unlock(dgbl->lock);
656 * Get the public random generator.
657 * Returns pointer to its EVP_RAND_CTX on success, NULL on failure.
659 EVP_RAND_CTX *RAND_get0_public(OSSL_LIB_CTX *ctx)
661 RAND_GLOBAL *dgbl = rand_get_global(ctx);
662 EVP_RAND_CTX *rand, *primary;
667 rand = CRYPTO_THREAD_get_local(&dgbl->public);
669 primary = RAND_get0_primary(ctx);
673 ctx = ossl_lib_ctx_get_concrete(ctx);
675 * If the private is also NULL then this is the first time we've
678 if (CRYPTO_THREAD_get_local(&dgbl->private) == NULL
679 && !ossl_init_thread_start(NULL, ctx, rand_delete_thread_state))
681 rand = rand_new_drbg(ctx, primary, SECONDARY_RESEED_INTERVAL,
682 SECONDARY_RESEED_TIME_INTERVAL);
683 CRYPTO_THREAD_set_local(&dgbl->public, rand);
689 * Get the private random generator.
690 * Returns pointer to its EVP_RAND_CTX on success, NULL on failure.
692 EVP_RAND_CTX *RAND_get0_private(OSSL_LIB_CTX *ctx)
694 RAND_GLOBAL *dgbl = rand_get_global(ctx);
695 EVP_RAND_CTX *rand, *primary;
700 rand = CRYPTO_THREAD_get_local(&dgbl->private);
702 primary = RAND_get0_primary(ctx);
706 ctx = ossl_lib_ctx_get_concrete(ctx);
708 * If the public is also NULL then this is the first time we've
711 if (CRYPTO_THREAD_get_local(&dgbl->public) == NULL
712 && !ossl_init_thread_start(NULL, ctx, rand_delete_thread_state))
714 rand = rand_new_drbg(ctx, primary, SECONDARY_RESEED_INTERVAL,
715 SECONDARY_RESEED_TIME_INTERVAL);
716 CRYPTO_THREAD_set_local(&dgbl->private, rand);
722 static int random_set_string(char **p, const char *s)
727 d = OPENSSL_strdup(s);
729 ERR_raise(ERR_LIB_CRYPTO, ERR_R_MALLOC_FAILURE);
739 * Load the DRBG definitions from a configuration file.
741 static int random_conf_init(CONF_IMODULE *md, const CONF *cnf)
743 STACK_OF(CONF_VALUE) *elist;
745 RAND_GLOBAL *dgbl = rand_get_global(cnf->libctx);
748 OSSL_TRACE1(CONF, "Loading random module: section %s\n",
749 CONF_imodule_get_value(md));
751 /* Value is a section containing RANDOM configuration */
752 elist = NCONF_get_section(cnf, CONF_imodule_get_value(md));
754 ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_RANDOM_SECTION_ERROR);
758 for (i = 0; i < sk_CONF_VALUE_num(elist); i++) {
759 cval = sk_CONF_VALUE_value(elist, i);
760 if (strcasecmp(cval->name, "random") == 0) {
761 if (!random_set_string(&dgbl->rng_name, cval->value))
763 } else if (strcasecmp(cval->name, "cipher") == 0) {
764 if (!random_set_string(&dgbl->rng_cipher, cval->value))
766 } else if (strcasecmp(cval->name, "digest") == 0) {
767 if (!random_set_string(&dgbl->rng_digest, cval->value))
769 } else if (strcasecmp(cval->name, "properties") == 0) {
770 if (!random_set_string(&dgbl->rng_propq, cval->value))
772 } else if (strcasecmp(cval->name, "seed") == 0) {
773 if (!random_set_string(&dgbl->seed_name, cval->value))
775 } else if (strcasecmp(cval->name, "seed_properties") == 0) {
776 if (!random_set_string(&dgbl->seed_propq, cval->value))
779 ERR_raise_data(ERR_LIB_CRYPTO,
780 CRYPTO_R_UNKNOWN_NAME_IN_RANDOM_SECTION,
781 "name=%s, value=%s", cval->name, cval->value);
789 static void random_conf_deinit(CONF_IMODULE *md)
791 OSSL_TRACE(CONF, "Cleaned up random\n");
794 void ossl_random_add_conf_module(void)
796 OSSL_TRACE(CONF, "Adding config module 'random'\n");
797 CONF_module_add("random", random_conf_init, random_conf_deinit);
800 int RAND_set_DRBG_type(OSSL_LIB_CTX *ctx, const char *drbg, const char *propq,
801 const char *cipher, const char *digest)
803 RAND_GLOBAL *dgbl = rand_get_global(ctx);
807 if (dgbl->primary != NULL) {
808 ERR_raise(ERR_LIB_CRYPTO, RAND_R_ALREADY_INSTANTIATED);
811 return random_set_string(&dgbl->rng_name, drbg)
812 && random_set_string(&dgbl->rng_propq, propq)
813 && random_set_string(&dgbl->rng_cipher, cipher)
814 && random_set_string(&dgbl->rng_digest, digest);
817 int RAND_set_seed_source_type(OSSL_LIB_CTX *ctx, const char *seed,
820 RAND_GLOBAL *dgbl = rand_get_global(ctx);
824 if (dgbl->primary != NULL) {
825 ERR_raise(ERR_LIB_CRYPTO, RAND_R_ALREADY_INSTANTIATED);
828 return random_set_string(&dgbl->seed_name, seed)
829 && random_set_string(&dgbl->seed_propq, propq);