/* * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the Apache License 2.0 (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy * in the file LICENSE in the source distribution or at * https://www.openssl.org/source/license.html */ /* We need to use some engine deprecated APIs */ #define OPENSSL_SUPPRESS_DEPRECATED #include #include #include #include #include #include #include "internal/cryptlib.h" #include #include "crypto/rand.h" #include "crypto/cryptlib.h" #include #include #include "internal/thread_once.h" #include "rand_local.h" #include "e_os.h" #ifndef FIPS_MODULE # include "crypto/rand_pool.h" # include "prov/seeding.h" # ifndef OPENSSL_NO_ENGINE /* non-NULL if default_RAND_meth is ENGINE-provided */ static ENGINE *funct_ref; static CRYPTO_RWLOCK *rand_engine_lock; # endif static CRYPTO_RWLOCK *rand_meth_lock; static const RAND_METHOD *default_RAND_meth; static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT; static int rand_inited = 0; DEFINE_RUN_ONCE_STATIC(do_rand_init) { # ifndef OPENSSL_NO_ENGINE rand_engine_lock = CRYPTO_THREAD_lock_new(); if (rand_engine_lock == NULL) return 0; # endif rand_meth_lock = CRYPTO_THREAD_lock_new(); if (rand_meth_lock == NULL) goto err; if (!rand_pool_init()) goto err; rand_inited = 1; return 1; err: CRYPTO_THREAD_lock_free(rand_meth_lock); rand_meth_lock = NULL; # ifndef OPENSSL_NO_ENGINE CRYPTO_THREAD_lock_free(rand_engine_lock); rand_engine_lock = NULL; # endif return 0; } void rand_cleanup_int(void) { const RAND_METHOD *meth = default_RAND_meth; if (!rand_inited) return; if (meth != NULL && meth->cleanup != NULL) meth->cleanup(); RAND_set_rand_method(NULL); rand_pool_cleanup(); # ifndef OPENSSL_NO_ENGINE CRYPTO_THREAD_lock_free(rand_engine_lock); rand_engine_lock = NULL; # endif CRYPTO_THREAD_lock_free(rand_meth_lock); rand_meth_lock = NULL; rand_inited = 0; } /* * RAND_close_seed_files() ensures that any seed file descriptors are * closed after use. This only applies to libcrypto/default provider, * it does not apply to other providers. */ void RAND_keep_random_devices_open(int keep) { if (RUN_ONCE(&rand_init, do_rand_init)) rand_pool_keep_random_devices_open(keep); } /* * RAND_poll() reseeds the default RNG using random input * * The random input is obtained from polling various entropy * sources which depend on the operating system and are * configurable via the --with-rand-seed configure option. */ int RAND_poll(void) { const RAND_METHOD *meth = RAND_get_rand_method(); int ret = meth == RAND_OpenSSL(); if (meth == NULL) return 0; #ifndef OPENSSL_NO_DEPRECATED_3_0 if (!ret) { /* fill random pool and seed the current legacy RNG */ RAND_POOL *pool = rand_pool_new(RAND_DRBG_STRENGTH, 1, (RAND_DRBG_STRENGTH + 7) / 8, RAND_POOL_MAX_LENGTH); if (pool == NULL) return 0; if (ossl_pool_acquire_entropy(pool) == 0) goto err; if (meth->add == NULL || meth->add(rand_pool_buffer(pool), rand_pool_length(pool), (rand_pool_entropy(pool) / 8.0)) == 0) goto err; ret = 1; err: rand_pool_free(pool); } #endif return ret; } int RAND_set_rand_method(const RAND_METHOD *meth) { if (!RUN_ONCE(&rand_init, do_rand_init)) return 0; CRYPTO_THREAD_write_lock(rand_meth_lock); # ifndef OPENSSL_NO_ENGINE ENGINE_finish(funct_ref); funct_ref = NULL; # endif default_RAND_meth = meth; CRYPTO_THREAD_unlock(rand_meth_lock); return 1; } const RAND_METHOD *RAND_get_rand_method(void) { const RAND_METHOD *tmp_meth = NULL; if (!RUN_ONCE(&rand_init, do_rand_init)) return NULL; CRYPTO_THREAD_write_lock(rand_meth_lock); if (default_RAND_meth == NULL) { # ifndef OPENSSL_NO_ENGINE ENGINE *e; /* If we have an engine that can do RAND, use it. */ if ((e = ENGINE_get_default_RAND()) != NULL && (tmp_meth = ENGINE_get_RAND(e)) != NULL) { funct_ref = e; default_RAND_meth = tmp_meth; } else { ENGINE_finish(e); default_RAND_meth = &rand_meth; } # else default_RAND_meth = &rand_meth; # endif } tmp_meth = default_RAND_meth; CRYPTO_THREAD_unlock(rand_meth_lock); return tmp_meth; } # if !defined(OPENSSL_NO_ENGINE) int RAND_set_rand_engine(ENGINE *engine) { const RAND_METHOD *tmp_meth = NULL; if (!RUN_ONCE(&rand_init, do_rand_init)) return 0; if (engine != NULL) { if (!ENGINE_init(engine)) return 0; tmp_meth = ENGINE_get_RAND(engine); if (tmp_meth == NULL) { ENGINE_finish(engine); return 0; } } CRYPTO_THREAD_write_lock(rand_engine_lock); /* This function releases any prior ENGINE so call it first */ RAND_set_rand_method(tmp_meth); funct_ref = engine; CRYPTO_THREAD_unlock(rand_engine_lock); return 1; } # endif void RAND_seed(const void *buf, int num) { const RAND_METHOD *meth = RAND_get_rand_method(); if (meth != NULL && meth->seed != NULL) meth->seed(buf, num); } void RAND_add(const void *buf, int num, double randomness) { const RAND_METHOD *meth = RAND_get_rand_method(); if (meth != NULL && meth->add != NULL) meth->add(buf, num, randomness); } # if !defined(OPENSSL_NO_DEPRECATED_1_1_0) int RAND_pseudo_bytes(unsigned char *buf, int num) { const RAND_METHOD *meth = RAND_get_rand_method(); if (meth != NULL && meth->pseudorand != NULL) return meth->pseudorand(buf, num); ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED); return -1; } # endif int RAND_status(void) { EVP_RAND_CTX *rand; const RAND_METHOD *meth = RAND_get_rand_method(); if (meth != NULL && meth != RAND_OpenSSL()) return meth->status != NULL ? meth->status() : 0; if ((rand = RAND_get0_primary(NULL)) == NULL) return 0; return EVP_RAND_state(rand) == EVP_RAND_STATE_READY; } #else /* !FIPS_MODULE */ const RAND_METHOD *RAND_get_rand_method(void) { return NULL; } #endif /* !FIPS_MODULE */ /* * This function is not part of RAND_METHOD, so if we're not using * the default method, then just call RAND_bytes(). Otherwise make * sure we're instantiated and use the private DRBG. */ int RAND_priv_bytes_ex(OSSL_LIB_CTX *ctx, unsigned char *buf, int num) { EVP_RAND_CTX *rand; const RAND_METHOD *meth = RAND_get_rand_method(); if (meth != NULL && meth != RAND_OpenSSL()) { if (meth->bytes != NULL) return meth->bytes(buf, num); ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED); return -1; } rand = RAND_get0_private(ctx); if (rand != NULL) return EVP_RAND_generate(rand, buf, num, 0, 0, NULL, 0); return 0; } int RAND_priv_bytes(unsigned char *buf, int num) { return RAND_priv_bytes_ex(NULL, buf, num); } int RAND_bytes_ex(OSSL_LIB_CTX *ctx, unsigned char *buf, int num) { EVP_RAND_CTX *rand; const RAND_METHOD *meth = RAND_get_rand_method(); if (meth != NULL && meth != RAND_OpenSSL()) { if (meth->bytes != NULL) return meth->bytes(buf, num); ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED); return -1; } rand = RAND_get0_public(ctx); if (rand != NULL) return EVP_RAND_generate(rand, buf, num, 0, 0, NULL, 0); return 0; } int RAND_bytes(unsigned char *buf, int num) { return RAND_bytes_ex(NULL, buf, num); } typedef struct rand_global_st { /* * The three shared DRBG instances * * There are three shared DRBG instances: , , and * . The and DRBGs are secondary ones. * These are used for non-secret (e.g. nonces) and secret * (e.g. private keys) data respectively. */ CRYPTO_RWLOCK *lock; EVP_RAND_CTX *seed; /* * The DRBG * * Not used directly by the application, only for reseeding the two other * DRBGs. It reseeds itself by pulling either randomness from os entropy * sources or by consuming randomness which was added by RAND_add(). * * The DRBG is a global instance which is accessed concurrently by * all threads. The necessary locking is managed automatically by its child * DRBG instances during reseeding. */ EVP_RAND_CTX *primary; /* * The DRBG * * Used by default for generating random bytes using RAND_bytes(). * * The secondary DRBG is thread-local, i.e., there is one instance * per thread. */ CRYPTO_THREAD_LOCAL public; /* * The DRBG * * Used by default for generating private keys using RAND_priv_bytes() * * The secondary DRBG is thread-local, i.e., there is one * instance per thread. */ CRYPTO_THREAD_LOCAL private; /* Which RNG is being used by default and it's configuration settings */ char *rng_name; char *rng_cipher; char *rng_digest; char *rng_propq; /* Allow the randomness source to be changed */ char *seed_name; char *seed_propq; } RAND_GLOBAL; /* * Initialize the OSSL_LIB_CTX global DRBGs on first use. * Returns the allocated global data on success or NULL on failure. */ static void *rand_ossl_ctx_new(OSSL_LIB_CTX *libctx) { RAND_GLOBAL *dgbl = OPENSSL_zalloc(sizeof(*dgbl)); if (dgbl == NULL) return NULL; #ifndef FIPS_MODULE /* * We need to ensure that base libcrypto thread handling has been * initialised. */ OPENSSL_init_crypto(0, NULL); #endif dgbl->lock = CRYPTO_THREAD_lock_new(); if (dgbl->lock == NULL) goto err1; if (!CRYPTO_THREAD_init_local(&dgbl->private, NULL)) goto err1; if (!CRYPTO_THREAD_init_local(&dgbl->public, NULL)) goto err2; return dgbl; err2: CRYPTO_THREAD_cleanup_local(&dgbl->private); err1: CRYPTO_THREAD_lock_free(dgbl->lock); OPENSSL_free(dgbl); return NULL; } static void rand_ossl_ctx_free(void *vdgbl) { RAND_GLOBAL *dgbl = vdgbl; if (dgbl == NULL) return; CRYPTO_THREAD_lock_free(dgbl->lock); CRYPTO_THREAD_cleanup_local(&dgbl->private); CRYPTO_THREAD_cleanup_local(&dgbl->public); EVP_RAND_CTX_free(dgbl->primary); EVP_RAND_CTX_free(dgbl->seed); OPENSSL_free(dgbl->rng_name); OPENSSL_free(dgbl->rng_cipher); OPENSSL_free(dgbl->rng_digest); OPENSSL_free(dgbl->rng_propq); OPENSSL_free(dgbl->seed_name); OPENSSL_free(dgbl->seed_propq); OPENSSL_free(dgbl); } static const OSSL_LIB_CTX_METHOD rand_drbg_ossl_ctx_method = { rand_ossl_ctx_new, rand_ossl_ctx_free, }; static RAND_GLOBAL *rand_get_global(OSSL_LIB_CTX *libctx) { return ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_DRBG_INDEX, &rand_drbg_ossl_ctx_method); } static void rand_delete_thread_state(void *arg) { OSSL_LIB_CTX *ctx = arg; RAND_GLOBAL *dgbl = rand_get_global(ctx); EVP_RAND_CTX *rand; if (dgbl == NULL) return; rand = CRYPTO_THREAD_get_local(&dgbl->public); CRYPTO_THREAD_set_local(&dgbl->public, NULL); EVP_RAND_CTX_free(rand); rand = CRYPTO_THREAD_get_local(&dgbl->private); CRYPTO_THREAD_set_local(&dgbl->private, NULL); EVP_RAND_CTX_free(rand); } #ifndef FIPS_MODULE static EVP_RAND_CTX *rand_new_seed(OSSL_LIB_CTX *libctx) { EVP_RAND *rand; RAND_GLOBAL *dgbl = rand_get_global(libctx); EVP_RAND_CTX *ctx; char *name; name = dgbl->seed_name != NULL ? dgbl->seed_name : "SEED-SRC"; rand = EVP_RAND_fetch(libctx, name, dgbl->seed_propq); if (rand == NULL) { ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_FETCH_DRBG); return NULL; } ctx = EVP_RAND_CTX_new(rand, NULL); EVP_RAND_free(rand); if (ctx == NULL) { ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_CREATE_DRBG); return NULL; } if (!EVP_RAND_instantiate(ctx, 0, 0, NULL, 0)) { ERR_raise(ERR_LIB_RAND, RAND_R_ERROR_INSTANTIATING_DRBG); EVP_RAND_CTX_free(ctx); return NULL; } return ctx; } #endif static EVP_RAND_CTX *rand_new_drbg(OSSL_LIB_CTX *libctx, EVP_RAND_CTX *parent, unsigned int reseed_interval, time_t reseed_time_interval) { EVP_RAND *rand; RAND_GLOBAL *dgbl = rand_get_global(libctx); EVP_RAND_CTX *ctx; OSSL_PARAM params[7], *p = params; char *name, *cipher; name = dgbl->rng_name != NULL ? dgbl->rng_name : "CTR-DRBG"; rand = EVP_RAND_fetch(libctx, name, dgbl->rng_propq); if (rand == NULL) { ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_FETCH_DRBG); return NULL; } ctx = EVP_RAND_CTX_new(rand, parent); EVP_RAND_free(rand); if (ctx == NULL) { ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_CREATE_DRBG); return NULL; } /* * Rather than trying to decode the DRBG settings, just pass them through * and rely on the other end to ignore those it doesn't care about. */ cipher = dgbl->rng_cipher != NULL ? dgbl->rng_cipher : "AES-256-CTR"; *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_CIPHER, cipher, 0); if (dgbl->rng_digest != NULL) *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_DIGEST, dgbl->rng_digest, 0); if (dgbl->rng_propq != NULL) *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_PROPERTIES, dgbl->rng_propq, 0); *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_MAC, "HMAC", 0); *p++ = OSSL_PARAM_construct_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS, &reseed_interval); *p++ = OSSL_PARAM_construct_time_t(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL, &reseed_time_interval); *p = OSSL_PARAM_construct_end(); if (!EVP_RAND_set_ctx_params(ctx, params)) { ERR_raise(ERR_LIB_RAND, RAND_R_ERROR_INITIALISING_DRBG); EVP_RAND_CTX_free(ctx); return NULL; } if (!EVP_RAND_instantiate(ctx, 0, 0, NULL, 0)) { ERR_raise(ERR_LIB_RAND, RAND_R_ERROR_INSTANTIATING_DRBG); EVP_RAND_CTX_free(ctx); return NULL; } return ctx; } /* * Get the primary random generator. * Returns pointer to its EVP_RAND_CTX on success, NULL on failure. * */ EVP_RAND_CTX *RAND_get0_primary(OSSL_LIB_CTX *ctx) { RAND_GLOBAL *dgbl = rand_get_global(ctx); if (dgbl == NULL) return NULL; if (dgbl->primary == NULL) { if (!CRYPTO_THREAD_write_lock(dgbl->lock)) return NULL; #ifndef FIPS_MODULE if (dgbl->seed == NULL) { ERR_set_mark(); dgbl->seed = rand_new_seed(ctx); ERR_pop_to_mark(); } #endif if (dgbl->primary == NULL) dgbl->primary = rand_new_drbg(ctx, dgbl->seed, PRIMARY_RESEED_INTERVAL, PRIMARY_RESEED_TIME_INTERVAL); /* * The primary DRBG may be shared between multiple threads so we must * enable locking. */ if (dgbl->primary != NULL && !EVP_RAND_enable_locking(dgbl->primary)) { ERR_raise(ERR_LIB_EVP, EVP_R_UNABLE_TO_ENABLE_LOCKING); EVP_RAND_CTX_free(dgbl->primary); dgbl->primary = NULL; CRYPTO_THREAD_lock_free(dgbl->lock); return NULL; } CRYPTO_THREAD_unlock(dgbl->lock); } return dgbl->primary; } /* * Get the public random generator. * Returns pointer to its EVP_RAND_CTX on success, NULL on failure. */ EVP_RAND_CTX *RAND_get0_public(OSSL_LIB_CTX *ctx) { RAND_GLOBAL *dgbl = rand_get_global(ctx); EVP_RAND_CTX *rand, *primary; if (dgbl == NULL) return NULL; rand = CRYPTO_THREAD_get_local(&dgbl->public); if (rand == NULL) { primary = RAND_get0_primary(ctx); if (primary == NULL) return NULL; ctx = ossl_lib_ctx_get_concrete(ctx); /* * If the private is also NULL then this is the first time we've * used this thread. */ if (CRYPTO_THREAD_get_local(&dgbl->private) == NULL && !ossl_init_thread_start(NULL, ctx, rand_delete_thread_state)) return NULL; rand = rand_new_drbg(ctx, primary, SECONDARY_RESEED_INTERVAL, SECONDARY_RESEED_TIME_INTERVAL); CRYPTO_THREAD_set_local(&dgbl->public, rand); } return rand; } /* * Get the private random generator. * Returns pointer to its EVP_RAND_CTX on success, NULL on failure. */ EVP_RAND_CTX *RAND_get0_private(OSSL_LIB_CTX *ctx) { RAND_GLOBAL *dgbl = rand_get_global(ctx); EVP_RAND_CTX *rand, *primary; if (dgbl == NULL) return NULL; rand = CRYPTO_THREAD_get_local(&dgbl->private); if (rand == NULL) { primary = RAND_get0_primary(ctx); if (primary == NULL) return NULL; ctx = ossl_lib_ctx_get_concrete(ctx); /* * If the public is also NULL then this is the first time we've * used this thread. */ if (CRYPTO_THREAD_get_local(&dgbl->public) == NULL && !ossl_init_thread_start(NULL, ctx, rand_delete_thread_state)) return NULL; rand = rand_new_drbg(ctx, primary, SECONDARY_RESEED_INTERVAL, SECONDARY_RESEED_TIME_INTERVAL); CRYPTO_THREAD_set_local(&dgbl->private, rand); } return rand; } #ifndef FIPS_MODULE static int random_set_string(char **p, const char *s) { char *d = OPENSSL_strdup(s); if (d == NULL) { ERR_raise(ERR_LIB_CRYPTO, ERR_R_MALLOC_FAILURE); return 0; } OPENSSL_free(*p); *p = d; return 1; } /* * Load the DRBG definitions from a configuration file. */ static int random_conf_init(CONF_IMODULE *md, const CONF *cnf) { STACK_OF(CONF_VALUE) *elist; CONF_VALUE *cval; RAND_GLOBAL *dgbl = rand_get_global(cnf->libctx); int i, r = 1; OSSL_TRACE1(CONF, "Loading random module: section %s\n", CONF_imodule_get_value(md)); /* Value is a section containing RANDOM configuration */ elist = NCONF_get_section(cnf, CONF_imodule_get_value(md)); if (elist == NULL) { ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_RANDOM_SECTION_ERROR); return 0; } for (i = 0; i < sk_CONF_VALUE_num(elist); i++) { cval = sk_CONF_VALUE_value(elist, i); if (strcasecmp(cval->name, "random") == 0) { if (!random_set_string(&dgbl->rng_name, cval->value)) return 0; } else if (strcasecmp(cval->name, "cipher") == 0) { if (!random_set_string(&dgbl->rng_cipher, cval->value)) return 0; } else if (strcasecmp(cval->name, "digest") == 0) { if (!random_set_string(&dgbl->rng_digest, cval->value)) return 0; } else if (strcasecmp(cval->name, "properties") == 0) { if (!random_set_string(&dgbl->rng_propq, cval->value)) return 0; } else if (strcasecmp(cval->name, "seed") == 0) { if (!random_set_string(&dgbl->seed_name, cval->value)) return 0; } else if (strcasecmp(cval->name, "seed_properties") == 0) { if (!random_set_string(&dgbl->seed_propq, cval->value)) return 0; } else { ERR_raise_data(ERR_LIB_CRYPTO, CRYPTO_R_UNKNOWN_NAME_IN_RANDOM_SECTION, "name=%s, value=%s", cval->name, cval->value); r = 0; } } return r; } static void random_conf_deinit(CONF_IMODULE *md) { OSSL_TRACE(CONF, "Cleaned up random\n"); } void ossl_random_add_conf_module(void) { OSSL_TRACE(CONF, "Adding config module 'random'\n"); CONF_module_add("random", random_conf_init, random_conf_deinit); } #endif