| /* |
| * Copyright 2011-2021 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 |
| */ |
| |
| #include <string.h> |
| #include <openssl/crypto.h> |
| #include <openssl/err.h> |
| #include <openssl/rand.h> |
| #include <openssl/evp.h> |
| #include "crypto/rand.h" |
| #include <openssl/proverr.h> |
| #include "drbg_local.h" |
| #include "internal/thread_once.h" |
| #include "crypto/cryptlib.h" |
| #include "prov/seeding.h" |
| #include "crypto/rand_pool.h" |
| #include "prov/provider_ctx.h" |
| #include "prov/providercommon.h" |
| |
| /* |
| * Support framework for NIST SP 800-90A DRBG |
| * |
| * See manual page PROV_DRBG(7) for a general overview. |
| * |
| * The OpenSSL model is to have new and free functions, and that new |
| * does all initialization. That is not the NIST model, which has |
| * instantiation and un-instantiate, and re-use within a new/free |
| * lifecycle. (No doubt this comes from the desire to support hardware |
| * DRBG, where allocation of resources on something like an HSM is |
| * a much bigger deal than just re-setting an allocated resource.) |
| */ |
| |
| /* NIST SP 800-90A DRBG recommends the use of a personalization string. */ |
| static const char ossl_pers_string[] = DRBG_DEFAULT_PERS_STRING; |
| |
| static const OSSL_DISPATCH *find_call(const OSSL_DISPATCH *dispatch, |
| int function); |
| |
| static int rand_drbg_restart(PROV_DRBG *drbg); |
| |
| int ossl_drbg_lock(void *vctx) |
| { |
| PROV_DRBG *drbg = vctx; |
| |
| if (drbg == NULL || drbg->lock == NULL) |
| return 1; |
| return CRYPTO_THREAD_write_lock(drbg->lock); |
| } |
| |
| void ossl_drbg_unlock(void *vctx) |
| { |
| PROV_DRBG *drbg = vctx; |
| |
| if (drbg != NULL && drbg->lock != NULL) |
| CRYPTO_THREAD_unlock(drbg->lock); |
| } |
| |
| static int ossl_drbg_lock_parent(PROV_DRBG *drbg) |
| { |
| void *parent = drbg->parent; |
| |
| if (parent != NULL |
| && drbg->parent_lock != NULL |
| && !drbg->parent_lock(parent)) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_PARENT_LOCKING_NOT_ENABLED); |
| return 0; |
| } |
| return 1; |
| } |
| |
| static void ossl_drbg_unlock_parent(PROV_DRBG *drbg) |
| { |
| void *parent = drbg->parent; |
| |
| if (parent != NULL && drbg->parent_unlock != NULL) |
| drbg->parent_unlock(parent); |
| } |
| |
| static int get_parent_strength(PROV_DRBG *drbg, unsigned int *str) |
| { |
| OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END }; |
| void *parent = drbg->parent; |
| int res; |
| |
| if (drbg->parent_get_ctx_params == NULL) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_GET_PARENT_STRENGTH); |
| return 0; |
| } |
| |
| *params = OSSL_PARAM_construct_uint(OSSL_RAND_PARAM_STRENGTH, str); |
| if (!ossl_drbg_lock_parent(drbg)) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_LOCK_PARENT); |
| return 0; |
| } |
| res = drbg->parent_get_ctx_params(parent, params); |
| ossl_drbg_unlock_parent(drbg); |
| if (!res) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_GET_PARENT_STRENGTH); |
| return 0; |
| } |
| return 1; |
| } |
| |
| static unsigned int get_parent_reseed_count(PROV_DRBG *drbg) |
| { |
| OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END }; |
| void *parent = drbg->parent; |
| unsigned int r = 0; |
| |
| *params = OSSL_PARAM_construct_uint(OSSL_DRBG_PARAM_RESEED_COUNTER, &r); |
| if (!ossl_drbg_lock_parent(drbg)) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_LOCK_PARENT); |
| goto err; |
| } |
| if (!drbg->parent_get_ctx_params(parent, params)) |
| r = 0; |
| ossl_drbg_unlock_parent(drbg); |
| return r; |
| |
| err: |
| r = tsan_load(&drbg->reseed_counter) - 2; |
| if (r == 0) |
| r = UINT_MAX; |
| return r; |
| } |
| |
| /* |
| * Implements the get_entropy() callback |
| * |
| * If the DRBG has a parent, then the required amount of entropy input |
| * is fetched using the parent's ossl_prov_drbg_generate(). |
| * |
| * Otherwise, the entropy is polled from the system entropy sources |
| * using ossl_pool_acquire_entropy(). |
| * |
| * If a random pool has been added to the DRBG using RAND_add(), then |
| * its entropy will be used up first. |
| */ |
| size_t ossl_drbg_get_seed(void *vdrbg, unsigned char **pout, |
| int entropy, size_t min_len, |
| size_t max_len, int prediction_resistance, |
| const unsigned char *adin, size_t adin_len) |
| { |
| PROV_DRBG *drbg = (PROV_DRBG *)vdrbg; |
| size_t bytes_needed; |
| unsigned char *buffer; |
| |
| /* Figure out how many bytes we need */ |
| bytes_needed = entropy >= 0 ? (entropy + 7) / 8 : 0; |
| if (bytes_needed < min_len) |
| bytes_needed = min_len; |
| if (bytes_needed > max_len) |
| bytes_needed = max_len; |
| |
| /* Allocate storage */ |
| buffer = OPENSSL_secure_malloc(bytes_needed); |
| if (buffer == NULL) { |
| ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE); |
| return 0; |
| } |
| |
| /* |
| * Get random data. Include our DRBG address as |
| * additional input, in order to provide a distinction between |
| * different DRBG child instances. |
| * |
| * Note: using the sizeof() operator on a pointer triggers |
| * a warning in some static code analyzers, but it's |
| * intentional and correct here. |
| */ |
| if (!ossl_prov_drbg_generate(drbg, buffer, bytes_needed, |
| drbg->strength, prediction_resistance, |
| (unsigned char *)&drbg, sizeof(drbg))) { |
| OPENSSL_secure_clear_free(buffer, bytes_needed); |
| ERR_raise(ERR_LIB_PROV, PROV_R_GENERATE_ERROR); |
| return 0; |
| } |
| *pout = buffer; |
| return bytes_needed; |
| } |
| |
| /* Implements the cleanup_entropy() callback */ |
| void ossl_drbg_clear_seed(ossl_unused void *vdrbg, |
| unsigned char *out, size_t outlen) |
| { |
| OPENSSL_secure_clear_free(out, outlen); |
| } |
| |
| static size_t get_entropy(PROV_DRBG *drbg, unsigned char **pout, int entropy, |
| size_t min_len, size_t max_len, |
| int prediction_resistance) |
| { |
| size_t bytes; |
| unsigned int p_str; |
| |
| if (drbg->parent == NULL) |
| #ifdef FIPS_MODULE |
| return ossl_crngt_get_entropy(drbg, pout, entropy, min_len, max_len, |
| prediction_resistance); |
| #else |
| return ossl_prov_get_entropy(drbg->provctx, pout, entropy, min_len, |
| max_len); |
| #endif |
| |
| if (drbg->parent_get_seed == NULL) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_PARENT_CANNOT_SUPPLY_ENTROPY_SEED); |
| return 0; |
| } |
| if (!get_parent_strength(drbg, &p_str)) |
| return 0; |
| if (drbg->strength > p_str) { |
| /* |
| * We currently don't support the algorithm from NIST SP 800-90C |
| * 10.1.2 to use a weaker DRBG as source |
| */ |
| ERR_raise(ERR_LIB_PROV, PROV_R_PARENT_STRENGTH_TOO_WEAK); |
| return 0; |
| } |
| |
| /* |
| * Our lock is already held, but we need to lock our parent before |
| * generating bits from it. Note: taking the lock will be a no-op |
| * if locking is not required (while drbg->parent->lock == NULL). |
| */ |
| if (!ossl_drbg_lock_parent(drbg)) |
| return 0; |
| /* |
| * Get random data from parent. Include our DRBG address as |
| * additional input, in order to provide a distinction between |
| * different DRBG child instances. |
| * |
| * Note: using the sizeof() operator on a pointer triggers |
| * a warning in some static code analyzers, but it's |
| * intentional and correct here. |
| */ |
| bytes = drbg->parent_get_seed(drbg->parent, pout, drbg->strength, |
| min_len, max_len, prediction_resistance, |
| (unsigned char *)&drbg, sizeof(drbg)); |
| ossl_drbg_unlock_parent(drbg); |
| return bytes; |
| } |
| |
| static void cleanup_entropy(PROV_DRBG *drbg, unsigned char *out, size_t outlen) |
| { |
| if (drbg->parent == NULL) { |
| #ifdef FIPS_MODULE |
| ossl_crngt_cleanup_entropy(drbg, out, outlen); |
| #else |
| ossl_prov_cleanup_entropy(drbg->provctx, out, outlen); |
| #endif |
| } else if (drbg->parent_clear_seed != NULL) { |
| if (!ossl_drbg_lock_parent(drbg)) |
| return; |
| drbg->parent_clear_seed(drbg, out, outlen); |
| ossl_drbg_unlock_parent(drbg); |
| } |
| } |
| |
| #ifndef PROV_RAND_GET_RANDOM_NONCE |
| typedef struct prov_drbg_nonce_global_st { |
| CRYPTO_RWLOCK *rand_nonce_lock; |
| int rand_nonce_count; |
| } PROV_DRBG_NONCE_GLOBAL; |
| |
| /* |
| * drbg_ossl_ctx_new() calls drgb_setup() which calls rand_drbg_get_nonce() |
| * which needs to get the rand_nonce_lock out of the OSSL_LIB_CTX...but since |
| * drbg_ossl_ctx_new() hasn't finished running yet we need the rand_nonce_lock |
| * to be in a different global data object. Otherwise we will go into an |
| * infinite recursion loop. |
| */ |
| static void *prov_drbg_nonce_ossl_ctx_new(OSSL_LIB_CTX *libctx) |
| { |
| PROV_DRBG_NONCE_GLOBAL *dngbl = OPENSSL_zalloc(sizeof(*dngbl)); |
| |
| if (dngbl == NULL) |
| return NULL; |
| |
| dngbl->rand_nonce_lock = CRYPTO_THREAD_lock_new(); |
| if (dngbl->rand_nonce_lock == NULL) { |
| OPENSSL_free(dngbl); |
| return NULL; |
| } |
| |
| return dngbl; |
| } |
| |
| static void prov_drbg_nonce_ossl_ctx_free(void *vdngbl) |
| { |
| PROV_DRBG_NONCE_GLOBAL *dngbl = vdngbl; |
| |
| if (dngbl == NULL) |
| return; |
| |
| CRYPTO_THREAD_lock_free(dngbl->rand_nonce_lock); |
| |
| OPENSSL_free(dngbl); |
| } |
| |
| static const OSSL_LIB_CTX_METHOD drbg_nonce_ossl_ctx_method = { |
| OSSL_LIB_CTX_METHOD_DEFAULT_PRIORITY, |
| prov_drbg_nonce_ossl_ctx_new, |
| prov_drbg_nonce_ossl_ctx_free, |
| }; |
| |
| /* Get a nonce from the operating system */ |
| static size_t prov_drbg_get_nonce(PROV_DRBG *drbg, unsigned char **pout, |
| size_t min_len, size_t max_len) |
| { |
| size_t ret = 0, n; |
| unsigned char *buf = NULL; |
| OSSL_LIB_CTX *libctx = ossl_prov_ctx_get0_libctx(drbg->provctx); |
| PROV_DRBG_NONCE_GLOBAL *dngbl |
| = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_DRBG_NONCE_INDEX, |
| &drbg_nonce_ossl_ctx_method); |
| struct { |
| void *drbg; |
| int count; |
| } data; |
| |
| if (dngbl == NULL) |
| return 0; |
| |
| if (drbg->parent != NULL && drbg->parent_nonce != NULL) { |
| n = drbg->parent_nonce(drbg->parent, NULL, 0, drbg->min_noncelen, |
| drbg->max_noncelen); |
| if (n > 0 && (buf = OPENSSL_malloc(n)) != NULL) { |
| ret = drbg->parent_nonce(drbg->parent, buf, 0, |
| drbg->min_noncelen, drbg->max_noncelen); |
| if (ret == n) { |
| *pout = buf; |
| return ret; |
| } |
| OPENSSL_free(buf); |
| } |
| } |
| |
| /* Use the built in nonce source plus some of our specifics */ |
| memset(&data, 0, sizeof(data)); |
| data.drbg = drbg; |
| CRYPTO_atomic_add(&dngbl->rand_nonce_count, 1, &data.count, |
| dngbl->rand_nonce_lock); |
| return ossl_prov_get_nonce(drbg->provctx, pout, min_len, max_len, |
| &data, sizeof(data)); |
| } |
| #endif /* PROV_RAND_GET_RANDOM_NONCE */ |
| |
| /* |
| * Instantiate |drbg|, after it has been initialized. Use |pers| and |
| * |perslen| as prediction-resistance input. |
| * |
| * Requires that drbg->lock is already locked for write, if non-null. |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int ossl_prov_drbg_instantiate(PROV_DRBG *drbg, unsigned int strength, |
| int prediction_resistance, |
| const unsigned char *pers, size_t perslen) |
| { |
| unsigned char *nonce = NULL, *entropy = NULL; |
| size_t noncelen = 0, entropylen = 0; |
| size_t min_entropy, min_entropylen, max_entropylen; |
| |
| if (strength > drbg->strength) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_INSUFFICIENT_DRBG_STRENGTH); |
| goto end; |
| } |
| min_entropy = drbg->strength; |
| min_entropylen = drbg->min_entropylen; |
| max_entropylen = drbg->max_entropylen; |
| |
| if (pers == NULL) { |
| pers = (const unsigned char *)ossl_pers_string; |
| perslen = sizeof(ossl_pers_string); |
| } |
| if (perslen > drbg->max_perslen) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_PERSONALISATION_STRING_TOO_LONG); |
| goto end; |
| } |
| |
| if (drbg->state != EVP_RAND_STATE_UNINITIALISED) { |
| if (drbg->state == EVP_RAND_STATE_ERROR) |
| ERR_raise(ERR_LIB_PROV, PROV_R_IN_ERROR_STATE); |
| else |
| ERR_raise(ERR_LIB_PROV, PROV_R_ALREADY_INSTANTIATED); |
| goto end; |
| } |
| |
| drbg->state = EVP_RAND_STATE_ERROR; |
| |
| if (drbg->min_noncelen > 0) { |
| if (drbg->parent_nonce != NULL) { |
| noncelen = drbg->parent_nonce(drbg->parent, NULL, drbg->strength, |
| drbg->min_noncelen, |
| drbg->max_noncelen); |
| if (noncelen == 0) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_ERROR_RETRIEVING_NONCE); |
| goto end; |
| } |
| nonce = OPENSSL_malloc(noncelen); |
| if (nonce == NULL) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_ERROR_RETRIEVING_NONCE); |
| goto end; |
| } |
| if (noncelen != drbg->parent_nonce(drbg->parent, nonce, |
| drbg->strength, |
| drbg->min_noncelen, |
| drbg->max_noncelen)) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_ERROR_RETRIEVING_NONCE); |
| goto end; |
| } |
| #ifndef PROV_RAND_GET_RANDOM_NONCE |
| } else if (drbg->parent != NULL) { |
| #endif |
| /* |
| * NIST SP800-90Ar1 section 9.1 says you can combine getting |
| * the entropy and nonce in 1 call by increasing the entropy |
| * with 50% and increasing the minimum length to accommodate |
| * the length of the nonce. We do this in case a nonce is |
| * required and there is no parental nonce capability. |
| */ |
| min_entropy += drbg->strength / 2; |
| min_entropylen += drbg->min_noncelen; |
| max_entropylen += drbg->max_noncelen; |
| } |
| #ifndef PROV_RAND_GET_RANDOM_NONCE |
| else { /* parent == NULL */ |
| noncelen = prov_drbg_get_nonce(drbg, &nonce, drbg->min_noncelen, |
| drbg->max_noncelen); |
| if (noncelen < drbg->min_noncelen |
| || noncelen > drbg->max_noncelen) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_ERROR_RETRIEVING_NONCE); |
| goto end; |
| } |
| } |
| #endif |
| } |
| |
| drbg->reseed_next_counter = tsan_load(&drbg->reseed_counter); |
| if (drbg->reseed_next_counter) { |
| drbg->reseed_next_counter++; |
| if (!drbg->reseed_next_counter) |
| drbg->reseed_next_counter = 1; |
| } |
| |
| entropylen = get_entropy(drbg, &entropy, min_entropy, |
| min_entropylen, max_entropylen, |
| prediction_resistance); |
| if (entropylen < min_entropylen |
| || entropylen > max_entropylen) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_ERROR_RETRIEVING_ENTROPY); |
| goto end; |
| } |
| |
| if (!drbg->instantiate(drbg, entropy, entropylen, nonce, noncelen, |
| pers, perslen)) { |
| cleanup_entropy(drbg, entropy, entropylen); |
| ERR_raise(ERR_LIB_PROV, PROV_R_ERROR_INSTANTIATING_DRBG); |
| goto end; |
| } |
| cleanup_entropy(drbg, entropy, entropylen); |
| |
| drbg->state = EVP_RAND_STATE_READY; |
| drbg->generate_counter = 1; |
| drbg->reseed_time = time(NULL); |
| tsan_store(&drbg->reseed_counter, drbg->reseed_next_counter); |
| |
| end: |
| if (nonce != NULL) |
| ossl_prov_cleanup_nonce(drbg->provctx, nonce, noncelen); |
| if (drbg->state == EVP_RAND_STATE_READY) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * Uninstantiate |drbg|. Must be instantiated before it can be used. |
| * |
| * Requires that drbg->lock is already locked for write, if non-null. |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int ossl_prov_drbg_uninstantiate(PROV_DRBG *drbg) |
| { |
| drbg->state = EVP_RAND_STATE_UNINITIALISED; |
| return 1; |
| } |
| |
| /* |
| * Reseed |drbg|, mixing in the specified data |
| * |
| * Requires that drbg->lock is already locked for write, if non-null. |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int ossl_prov_drbg_reseed(PROV_DRBG *drbg, int prediction_resistance, |
| const unsigned char *ent, size_t ent_len, |
| const unsigned char *adin, size_t adinlen) |
| { |
| unsigned char *entropy = NULL; |
| size_t entropylen = 0; |
| |
| if (!ossl_prov_is_running()) |
| return 0; |
| |
| if (drbg->state != EVP_RAND_STATE_READY) { |
| /* try to recover from previous errors */ |
| rand_drbg_restart(drbg); |
| |
| if (drbg->state == EVP_RAND_STATE_ERROR) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_IN_ERROR_STATE); |
| return 0; |
| } |
| if (drbg->state == EVP_RAND_STATE_UNINITIALISED) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_NOT_INSTANTIATED); |
| return 0; |
| } |
| } |
| |
| if (ent != NULL) { |
| if (ent_len < drbg->min_entropylen) { |
| ERR_raise(ERR_LIB_RAND, RAND_R_ENTROPY_OUT_OF_RANGE); |
| drbg->state = EVP_RAND_STATE_ERROR; |
| return 0; |
| } |
| if (ent_len > drbg->max_entropylen) { |
| ERR_raise(ERR_LIB_RAND, RAND_R_ENTROPY_INPUT_TOO_LONG); |
| drbg->state = EVP_RAND_STATE_ERROR; |
| return 0; |
| } |
| } |
| |
| if (adin == NULL) { |
| adinlen = 0; |
| } else if (adinlen > drbg->max_adinlen) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_ADDITIONAL_INPUT_TOO_LONG); |
| return 0; |
| } |
| |
| drbg->state = EVP_RAND_STATE_ERROR; |
| |
| drbg->reseed_next_counter = tsan_load(&drbg->reseed_counter); |
| if (drbg->reseed_next_counter) { |
| drbg->reseed_next_counter++; |
| if (!drbg->reseed_next_counter) |
| drbg->reseed_next_counter = 1; |
| } |
| |
| if (ent != NULL) { |
| #ifdef FIPS_MODULE |
| /* |
| * NIST SP-800-90A mandates that entropy *shall not* be provided |
| * by the consuming application. Instead the data is added as additional |
| * input. |
| * |
| * (NIST SP-800-90Ar1, Sections 9.1 and 9.2) |
| */ |
| if (!drbg->reseed(drbg, NULL, 0, ent, ent_len)) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_RESEED); |
| return 0; |
| } |
| #else |
| if (!drbg->reseed(drbg, ent, ent_len, adin, adinlen)) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_RESEED); |
| return 0; |
| } |
| /* There isn't much point adding the same additional input twice */ |
| adin = NULL; |
| adinlen = 0; |
| #endif |
| } |
| |
| /* Reseed using our sources in addition */ |
| entropylen = get_entropy(drbg, &entropy, drbg->strength, |
| drbg->min_entropylen, drbg->max_entropylen, |
| prediction_resistance); |
| if (entropylen < drbg->min_entropylen |
| || entropylen > drbg->max_entropylen) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_ERROR_RETRIEVING_ENTROPY); |
| goto end; |
| } |
| |
| if (!drbg->reseed(drbg, entropy, entropylen, adin, adinlen)) |
| goto end; |
| |
| drbg->state = EVP_RAND_STATE_READY; |
| drbg->generate_counter = 1; |
| drbg->reseed_time = time(NULL); |
| tsan_store(&drbg->reseed_counter, drbg->reseed_next_counter); |
| if (drbg->parent != NULL) |
| drbg->parent_reseed_counter = get_parent_reseed_count(drbg); |
| |
| end: |
| cleanup_entropy(drbg, entropy, entropylen); |
| if (drbg->state == EVP_RAND_STATE_READY) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * Generate |outlen| bytes into the buffer at |out|. Reseed if we need |
| * to or if |prediction_resistance| is set. Additional input can be |
| * sent in |adin| and |adinlen|. |
| * |
| * Requires that drbg->lock is already locked for write, if non-null. |
| * |
| * Returns 1 on success, 0 on failure. |
| * |
| */ |
| int ossl_prov_drbg_generate(PROV_DRBG *drbg, unsigned char *out, size_t outlen, |
| unsigned int strength, int prediction_resistance, |
| const unsigned char *adin, size_t adinlen) |
| { |
| int fork_id; |
| int reseed_required = 0; |
| |
| if (!ossl_prov_is_running()) |
| return 0; |
| |
| if (drbg->state != EVP_RAND_STATE_READY) { |
| /* try to recover from previous errors */ |
| rand_drbg_restart(drbg); |
| |
| if (drbg->state == EVP_RAND_STATE_ERROR) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_IN_ERROR_STATE); |
| return 0; |
| } |
| if (drbg->state == EVP_RAND_STATE_UNINITIALISED) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_NOT_INSTANTIATED); |
| return 0; |
| } |
| } |
| if (strength > drbg->strength) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_INSUFFICIENT_DRBG_STRENGTH); |
| return 0; |
| } |
| |
| if (outlen > drbg->max_request) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_REQUEST_TOO_LARGE_FOR_DRBG); |
| return 0; |
| } |
| if (adinlen > drbg->max_adinlen) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_ADDITIONAL_INPUT_TOO_LONG); |
| return 0; |
| } |
| |
| fork_id = openssl_get_fork_id(); |
| |
| if (drbg->fork_id != fork_id) { |
| drbg->fork_id = fork_id; |
| reseed_required = 1; |
| } |
| |
| if (drbg->reseed_interval > 0) { |
| if (drbg->generate_counter >= drbg->reseed_interval) |
| reseed_required = 1; |
| } |
| if (drbg->reseed_time_interval > 0) { |
| time_t now = time(NULL); |
| if (now < drbg->reseed_time |
| || now - drbg->reseed_time >= drbg->reseed_time_interval) |
| reseed_required = 1; |
| } |
| if (drbg->parent != NULL |
| && get_parent_reseed_count(drbg) != drbg->parent_reseed_counter) |
| reseed_required = 1; |
| |
| if (reseed_required || prediction_resistance) { |
| if (!ossl_prov_drbg_reseed(drbg, prediction_resistance, NULL, 0, |
| adin, adinlen)) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_RESEED_ERROR); |
| return 0; |
| } |
| adin = NULL; |
| adinlen = 0; |
| } |
| |
| if (!drbg->generate(drbg, out, outlen, adin, adinlen)) { |
| drbg->state = EVP_RAND_STATE_ERROR; |
| ERR_raise(ERR_LIB_PROV, PROV_R_GENERATE_ERROR); |
| return 0; |
| } |
| |
| drbg->generate_counter++; |
| |
| return 1; |
| } |
| |
| /* |
| * Restart |drbg|, using the specified entropy or additional input |
| * |
| * Tries its best to get the drbg instantiated by all means, |
| * regardless of its current state. |
| * |
| * Optionally, a |buffer| of |len| random bytes can be passed, |
| * which is assumed to contain at least |entropy| bits of entropy. |
| * |
| * If |entropy| > 0, the buffer content is used as entropy input. |
| * |
| * If |entropy| == 0, the buffer content is used as additional input |
| * |
| * Returns 1 on success, 0 on failure. |
| * |
| * This function is used internally only. |
| */ |
| static int rand_drbg_restart(PROV_DRBG *drbg) |
| { |
| /* repair error state */ |
| if (drbg->state == EVP_RAND_STATE_ERROR) |
| drbg->uninstantiate(drbg); |
| |
| /* repair uninitialized state */ |
| if (drbg->state == EVP_RAND_STATE_UNINITIALISED) |
| /* reinstantiate drbg */ |
| ossl_prov_drbg_instantiate(drbg, drbg->strength, 0, NULL, 0); |
| |
| return drbg->state == EVP_RAND_STATE_READY; |
| } |
| |
| /* Provider support from here down */ |
| static const OSSL_DISPATCH *find_call(const OSSL_DISPATCH *dispatch, |
| int function) |
| { |
| if (dispatch != NULL) |
| while (dispatch->function_id != 0) { |
| if (dispatch->function_id == function) |
| return dispatch; |
| dispatch++; |
| } |
| return NULL; |
| } |
| |
| int ossl_drbg_enable_locking(void *vctx) |
| { |
| PROV_DRBG *drbg = vctx; |
| |
| if (drbg != NULL && drbg->lock == NULL) { |
| if (drbg->parent_enable_locking != NULL) |
| if (!drbg->parent_enable_locking(drbg->parent)) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_PARENT_LOCKING_NOT_ENABLED); |
| return 0; |
| } |
| drbg->lock = CRYPTO_THREAD_lock_new(); |
| if (drbg->lock == NULL) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_CREATE_LOCK); |
| return 0; |
| } |
| } |
| return 1; |
| } |
| |
| /* |
| * Allocate memory and initialize a new DRBG. The DRBG is allocated on |
| * the secure heap if |secure| is nonzero and the secure heap is enabled. |
| * The |parent|, if not NULL, will be used as random source for reseeding. |
| * This also requires the parent's provider context and the parent's lock. |
| * |
| * Returns a pointer to the new DRBG instance on success, NULL on failure. |
| */ |
| PROV_DRBG *ossl_rand_drbg_new |
| (void *provctx, void *parent, const OSSL_DISPATCH *p_dispatch, |
| int (*dnew)(PROV_DRBG *ctx), |
| int (*instantiate)(PROV_DRBG *drbg, |
| const unsigned char *entropy, size_t entropylen, |
| const unsigned char *nonce, size_t noncelen, |
| const unsigned char *pers, size_t perslen), |
| int (*uninstantiate)(PROV_DRBG *ctx), |
| int (*reseed)(PROV_DRBG *drbg, const unsigned char *ent, size_t ent_len, |
| const unsigned char *adin, size_t adin_len), |
| int (*generate)(PROV_DRBG *, unsigned char *out, size_t outlen, |
| const unsigned char *adin, size_t adin_len)) |
| { |
| PROV_DRBG *drbg; |
| unsigned int p_str; |
| const OSSL_DISPATCH *pfunc; |
| |
| if (!ossl_prov_is_running()) |
| return NULL; |
| |
| drbg = OPENSSL_zalloc(sizeof(*drbg)); |
| if (drbg == NULL) { |
| ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE); |
| return NULL; |
| } |
| |
| drbg->provctx = provctx; |
| drbg->instantiate = instantiate; |
| drbg->uninstantiate = uninstantiate; |
| drbg->reseed = reseed; |
| drbg->generate = generate; |
| drbg->fork_id = openssl_get_fork_id(); |
| |
| /* Extract parent's functions */ |
| drbg->parent = parent; |
| if ((pfunc = find_call(p_dispatch, OSSL_FUNC_RAND_ENABLE_LOCKING)) != NULL) |
| drbg->parent_enable_locking = OSSL_FUNC_rand_enable_locking(pfunc); |
| if ((pfunc = find_call(p_dispatch, OSSL_FUNC_RAND_LOCK)) != NULL) |
| drbg->parent_lock = OSSL_FUNC_rand_lock(pfunc); |
| if ((pfunc = find_call(p_dispatch, OSSL_FUNC_RAND_UNLOCK)) != NULL) |
| drbg->parent_unlock = OSSL_FUNC_rand_unlock(pfunc); |
| if ((pfunc = find_call(p_dispatch, OSSL_FUNC_RAND_GET_CTX_PARAMS)) != NULL) |
| drbg->parent_get_ctx_params = OSSL_FUNC_rand_get_ctx_params(pfunc); |
| if ((pfunc = find_call(p_dispatch, OSSL_FUNC_RAND_NONCE)) != NULL) |
| drbg->parent_nonce = OSSL_FUNC_rand_nonce(pfunc); |
| if ((pfunc = find_call(p_dispatch, OSSL_FUNC_RAND_GET_SEED)) != NULL) |
| drbg->parent_get_seed = OSSL_FUNC_rand_get_seed(pfunc); |
| if ((pfunc = find_call(p_dispatch, OSSL_FUNC_RAND_CLEAR_SEED)) != NULL) |
| drbg->parent_clear_seed = OSSL_FUNC_rand_clear_seed(pfunc); |
| |
| /* Set some default maximums up */ |
| drbg->max_entropylen = DRBG_MAX_LENGTH; |
| drbg->max_noncelen = DRBG_MAX_LENGTH; |
| drbg->max_perslen = DRBG_MAX_LENGTH; |
| drbg->max_adinlen = DRBG_MAX_LENGTH; |
| drbg->generate_counter = 1; |
| drbg->reseed_counter = 1; |
| drbg->reseed_interval = RESEED_INTERVAL; |
| drbg->reseed_time_interval = TIME_INTERVAL; |
| |
| if (!dnew(drbg)) |
| goto err; |
| |
| if (parent != NULL) { |
| if (!get_parent_strength(drbg, &p_str)) |
| goto err; |
| if (drbg->strength > p_str) { |
| /* |
| * We currently don't support the algorithm from NIST SP 800-90C |
| * 10.1.2 to use a weaker DRBG as source |
| */ |
| ERR_raise(ERR_LIB_PROV, PROV_R_PARENT_STRENGTH_TOO_WEAK); |
| goto err; |
| } |
| } |
| #ifdef TSAN_REQUIRES_LOCKING |
| if (!ossl_drbg_enable_locking(drbg)) |
| goto err; |
| #endif |
| return drbg; |
| |
| err: |
| ossl_rand_drbg_free(drbg); |
| return NULL; |
| } |
| |
| void ossl_rand_drbg_free(PROV_DRBG *drbg) |
| { |
| if (drbg == NULL) |
| return; |
| |
| CRYPTO_THREAD_lock_free(drbg->lock); |
| OPENSSL_free(drbg); |
| } |
| |
| int ossl_drbg_get_ctx_params(PROV_DRBG *drbg, OSSL_PARAM params[]) |
| { |
| OSSL_PARAM *p; |
| |
| p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_STATE); |
| if (p != NULL && !OSSL_PARAM_set_int(p, drbg->state)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_STRENGTH); |
| if (p != NULL && !OSSL_PARAM_set_int(p, drbg->strength)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_MAX_REQUEST); |
| if (p != NULL && !OSSL_PARAM_set_size_t(p, drbg->max_request)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_MIN_ENTROPYLEN); |
| if (p != NULL && !OSSL_PARAM_set_size_t(p, drbg->min_entropylen)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_MAX_ENTROPYLEN); |
| if (p != NULL && !OSSL_PARAM_set_size_t(p, drbg->max_entropylen)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_MIN_NONCELEN); |
| if (p != NULL && !OSSL_PARAM_set_size_t(p, drbg->min_noncelen)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_MAX_NONCELEN); |
| if (p != NULL && !OSSL_PARAM_set_size_t(p, drbg->max_noncelen)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_MAX_PERSLEN); |
| if (p != NULL && !OSSL_PARAM_set_size_t(p, drbg->max_perslen)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_MAX_ADINLEN); |
| if (p != NULL && !OSSL_PARAM_set_size_t(p, drbg->max_adinlen)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_RESEED_REQUESTS); |
| if (p != NULL && !OSSL_PARAM_set_uint(p, drbg->reseed_interval)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_RESEED_TIME); |
| if (p != NULL && !OSSL_PARAM_set_time_t(p, drbg->reseed_time)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL); |
| if (p != NULL && !OSSL_PARAM_set_time_t(p, drbg->reseed_time_interval)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_RESEED_COUNTER); |
| if (p != NULL |
| && !OSSL_PARAM_set_uint(p, tsan_load(&drbg->reseed_counter))) |
| return 0; |
| return 1; |
| } |
| |
| int ossl_drbg_set_ctx_params(PROV_DRBG *drbg, const OSSL_PARAM params[]) |
| { |
| const OSSL_PARAM *p; |
| |
| if (params == NULL) |
| return 1; |
| |
| p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_RESEED_REQUESTS); |
| if (p != NULL && !OSSL_PARAM_get_uint(p, &drbg->reseed_interval)) |
| return 0; |
| |
| p = OSSL_PARAM_locate_const(params, OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL); |
| if (p != NULL && !OSSL_PARAM_get_time_t(p, &drbg->reseed_time_interval)) |
| return 0; |
| return 1; |
| } |
