| /* |
| * Copyright 2011-2020 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the OpenSSL license (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 "rand_local.h" |
| #include "internal/thread_once.h" |
| #include "crypto/rand.h" |
| #include "crypto/cryptlib.h" |
| |
| /* |
| * Support framework for NIST SP 800-90A DRBG |
| * |
| * See manual page RAND_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.) |
| */ |
| |
| /* |
| * The three shared DRBG instances |
| * |
| * There are three shared DRBG instances: <master>, <public>, and <private>. |
| */ |
| |
| /* |
| * The <master> 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 <master> 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. |
| */ |
| static RAND_DRBG *master_drbg; |
| /* |
| * The <public> DRBG |
| * |
| * Used by default for generating random bytes using RAND_bytes(). |
| * |
| * The <public> DRBG is thread-local, i.e., there is one instance per thread. |
| */ |
| static CRYPTO_THREAD_LOCAL public_drbg; |
| /* |
| * The <private> DRBG |
| * |
| * Used by default for generating private keys using RAND_priv_bytes() |
| * |
| * The <private> DRBG is thread-local, i.e., there is one instance per thread. |
| */ |
| static CRYPTO_THREAD_LOCAL private_drbg; |
| |
| |
| |
| /* NIST SP 800-90A DRBG recommends the use of a personalization string. */ |
| static const char ossl_pers_string[] = "OpenSSL NIST SP 800-90A DRBG"; |
| |
| static CRYPTO_ONCE rand_drbg_init = CRYPTO_ONCE_STATIC_INIT; |
| |
| |
| |
| static int rand_drbg_type = RAND_DRBG_TYPE; |
| static unsigned int rand_drbg_flags = RAND_DRBG_FLAGS; |
| |
| static unsigned int master_reseed_interval = MASTER_RESEED_INTERVAL; |
| static unsigned int slave_reseed_interval = SLAVE_RESEED_INTERVAL; |
| |
| static time_t master_reseed_time_interval = MASTER_RESEED_TIME_INTERVAL; |
| static time_t slave_reseed_time_interval = SLAVE_RESEED_TIME_INTERVAL; |
| |
| /* A logical OR of all used DRBG flag bits (currently there is only one) */ |
| static const unsigned int rand_drbg_used_flags = |
| RAND_DRBG_FLAG_CTR_NO_DF; |
| |
| static RAND_DRBG *drbg_setup(RAND_DRBG *parent); |
| |
| static RAND_DRBG *rand_drbg_new(int secure, |
| int type, |
| unsigned int flags, |
| RAND_DRBG *parent); |
| |
| /* |
| * Set/initialize |drbg| to be of type |type|, with optional |flags|. |
| * |
| * If |type| and |flags| are zero, use the defaults |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags) |
| { |
| int ret = 1; |
| |
| if (type == 0 && flags == 0) { |
| type = rand_drbg_type; |
| flags = rand_drbg_flags; |
| } |
| |
| /* If set is called multiple times - clear the old one */ |
| if (drbg->type != 0 && (type != drbg->type || flags != drbg->flags)) { |
| drbg->meth->uninstantiate(drbg); |
| rand_pool_free(drbg->adin_pool); |
| drbg->adin_pool = NULL; |
| } |
| |
| drbg->state = DRBG_UNINITIALISED; |
| drbg->flags = flags; |
| drbg->type = type; |
| |
| switch (type) { |
| default: |
| drbg->type = 0; |
| drbg->flags = 0; |
| drbg->meth = NULL; |
| RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE); |
| return 0; |
| case 0: |
| /* Uninitialized; that's okay. */ |
| drbg->meth = NULL; |
| return 1; |
| case NID_aes_128_ctr: |
| case NID_aes_192_ctr: |
| case NID_aes_256_ctr: |
| ret = drbg_ctr_init(drbg); |
| break; |
| } |
| |
| if (ret == 0) { |
| drbg->state = DRBG_ERROR; |
| RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG); |
| } |
| return ret; |
| } |
| |
| /* |
| * Set/initialize default |type| and |flag| for new drbg instances. |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int RAND_DRBG_set_defaults(int type, unsigned int flags) |
| { |
| int ret = 1; |
| |
| switch (type) { |
| default: |
| RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_TYPE); |
| return 0; |
| case NID_aes_128_ctr: |
| case NID_aes_192_ctr: |
| case NID_aes_256_ctr: |
| break; |
| } |
| |
| if ((flags & ~rand_drbg_used_flags) != 0) { |
| RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_FLAGS); |
| return 0; |
| } |
| |
| rand_drbg_type = type; |
| rand_drbg_flags = flags; |
| |
| return ret; |
| } |
| |
| |
| /* |
| * 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. |
| * |
| * Returns a pointer to the new DRBG instance on success, NULL on failure. |
| */ |
| static RAND_DRBG *rand_drbg_new(int secure, |
| int type, |
| unsigned int flags, |
| RAND_DRBG *parent) |
| { |
| RAND_DRBG *drbg = secure ? OPENSSL_secure_zalloc(sizeof(*drbg)) |
| : OPENSSL_zalloc(sizeof(*drbg)); |
| |
| if (drbg == NULL) { |
| RANDerr(RAND_F_RAND_DRBG_NEW, ERR_R_MALLOC_FAILURE); |
| return NULL; |
| } |
| |
| drbg->secure = secure && CRYPTO_secure_allocated(drbg); |
| drbg->fork_id = openssl_get_fork_id(); |
| drbg->parent = parent; |
| |
| if (parent == NULL) { |
| drbg->get_entropy = rand_drbg_get_entropy; |
| drbg->cleanup_entropy = rand_drbg_cleanup_entropy; |
| #ifndef RAND_DRBG_GET_RANDOM_NONCE |
| drbg->get_nonce = rand_drbg_get_nonce; |
| drbg->cleanup_nonce = rand_drbg_cleanup_nonce; |
| #endif |
| |
| drbg->reseed_interval = master_reseed_interval; |
| drbg->reseed_time_interval = master_reseed_time_interval; |
| } else { |
| drbg->get_entropy = rand_drbg_get_entropy; |
| drbg->cleanup_entropy = rand_drbg_cleanup_entropy; |
| /* |
| * Do not provide nonce callbacks, the child DRBGs will |
| * obtain their nonce using random bits from the parent. |
| */ |
| |
| drbg->reseed_interval = slave_reseed_interval; |
| drbg->reseed_time_interval = slave_reseed_time_interval; |
| } |
| |
| if (RAND_DRBG_set(drbg, type, flags) == 0) |
| goto err; |
| |
| if (parent != NULL) { |
| rand_drbg_lock(parent); |
| if (drbg->strength > parent->strength) { |
| /* |
| * We currently don't support the algorithm from NIST SP 800-90C |
| * 10.1.2 to use a weaker DRBG as source |
| */ |
| rand_drbg_unlock(parent); |
| RANDerr(RAND_F_RAND_DRBG_NEW, RAND_R_PARENT_STRENGTH_TOO_WEAK); |
| goto err; |
| } |
| rand_drbg_unlock(parent); |
| } |
| |
| return drbg; |
| |
| err: |
| RAND_DRBG_free(drbg); |
| |
| return NULL; |
| } |
| |
| RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent) |
| { |
| return rand_drbg_new(0, type, flags, parent); |
| } |
| |
| RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent) |
| { |
| return rand_drbg_new(1, type, flags, parent); |
| } |
| |
| /* |
| * Uninstantiate |drbg| and free all memory. |
| */ |
| void RAND_DRBG_free(RAND_DRBG *drbg) |
| { |
| if (drbg == NULL) |
| return; |
| |
| if (drbg->meth != NULL) |
| drbg->meth->uninstantiate(drbg); |
| rand_pool_free(drbg->adin_pool); |
| CRYPTO_THREAD_lock_free(drbg->lock); |
| CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data); |
| |
| if (drbg->secure) |
| OPENSSL_secure_clear_free(drbg, sizeof(*drbg)); |
| else |
| OPENSSL_clear_free(drbg, sizeof(*drbg)); |
| } |
| |
| /* |
| * 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 RAND_DRBG_instantiate(RAND_DRBG *drbg, |
| const unsigned char *pers, size_t perslen) |
| { |
| unsigned char *nonce = NULL, *entropy = NULL; |
| size_t noncelen = 0, entropylen = 0; |
| size_t min_entropy = drbg->strength; |
| size_t min_entropylen = drbg->min_entropylen; |
| size_t max_entropylen = drbg->max_entropylen; |
| |
| if (perslen > drbg->max_perslen) { |
| RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, |
| RAND_R_PERSONALISATION_STRING_TOO_LONG); |
| goto end; |
| } |
| |
| if (drbg->meth == NULL) { |
| RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, |
| RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED); |
| goto end; |
| } |
| |
| if (drbg->state != DRBG_UNINITIALISED) { |
| RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, |
| drbg->state == DRBG_ERROR ? RAND_R_IN_ERROR_STATE |
| : RAND_R_ALREADY_INSTANTIATED); |
| goto end; |
| } |
| |
| drbg->state = DRBG_ERROR; |
| |
| /* |
| * 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 require and get_nonce is NULL. |
| */ |
| if (drbg->min_noncelen > 0 && drbg->get_nonce == NULL) { |
| min_entropy += drbg->strength / 2; |
| min_entropylen += drbg->min_noncelen; |
| max_entropylen += drbg->max_noncelen; |
| } |
| |
| drbg->reseed_next_counter = tsan_load(&drbg->reseed_prop_counter); |
| if (drbg->reseed_next_counter) { |
| drbg->reseed_next_counter++; |
| if(!drbg->reseed_next_counter) |
| drbg->reseed_next_counter = 1; |
| } |
| |
| if (drbg->get_entropy != NULL) |
| entropylen = drbg->get_entropy(drbg, &entropy, min_entropy, |
| min_entropylen, max_entropylen, 0); |
| if (entropylen < min_entropylen |
| || entropylen > max_entropylen) { |
| RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_ENTROPY); |
| goto end; |
| } |
| |
| if (drbg->min_noncelen > 0 && drbg->get_nonce != NULL) { |
| noncelen = drbg->get_nonce(drbg, &nonce, drbg->strength / 2, |
| drbg->min_noncelen, drbg->max_noncelen); |
| if (noncelen < drbg->min_noncelen || noncelen > drbg->max_noncelen) { |
| RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_NONCE); |
| goto end; |
| } |
| } |
| |
| if (!drbg->meth->instantiate(drbg, entropy, entropylen, |
| nonce, noncelen, pers, perslen)) { |
| RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_INSTANTIATING_DRBG); |
| goto end; |
| } |
| |
| drbg->state = DRBG_READY; |
| drbg->reseed_gen_counter = 1; |
| drbg->reseed_time = time(NULL); |
| tsan_store(&drbg->reseed_prop_counter, drbg->reseed_next_counter); |
| |
| end: |
| if (entropy != NULL && drbg->cleanup_entropy != NULL) |
| drbg->cleanup_entropy(drbg, entropy, entropylen); |
| if (nonce != NULL && drbg->cleanup_nonce != NULL) |
| drbg->cleanup_nonce(drbg, nonce, noncelen); |
| if (drbg->state == DRBG_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 RAND_DRBG_uninstantiate(RAND_DRBG *drbg) |
| { |
| if (drbg->meth == NULL) { |
| drbg->state = DRBG_ERROR; |
| RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE, |
| RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED); |
| return 0; |
| } |
| |
| /* Clear the entire drbg->ctr struct, then reset some important |
| * members of the drbg->ctr struct (e.g. keysize, df_ks) to their |
| * initial values. |
| */ |
| drbg->meth->uninstantiate(drbg); |
| return RAND_DRBG_set(drbg, drbg->type, drbg->flags); |
| } |
| |
| /* |
| * 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 RAND_DRBG_reseed(RAND_DRBG *drbg, |
| const unsigned char *adin, size_t adinlen, |
| int prediction_resistance) |
| { |
| unsigned char *entropy = NULL; |
| size_t entropylen = 0; |
| |
| if (drbg->state == DRBG_ERROR) { |
| RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_IN_ERROR_STATE); |
| return 0; |
| } |
| if (drbg->state == DRBG_UNINITIALISED) { |
| RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_NOT_INSTANTIATED); |
| return 0; |
| } |
| |
| if (adin == NULL) { |
| adinlen = 0; |
| } else if (adinlen > drbg->max_adinlen) { |
| RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ADDITIONAL_INPUT_TOO_LONG); |
| return 0; |
| } |
| |
| drbg->state = DRBG_ERROR; |
| |
| drbg->reseed_next_counter = tsan_load(&drbg->reseed_prop_counter); |
| if (drbg->reseed_next_counter) { |
| drbg->reseed_next_counter++; |
| if(!drbg->reseed_next_counter) |
| drbg->reseed_next_counter = 1; |
| } |
| |
| if (drbg->get_entropy != NULL) |
| entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength, |
| drbg->min_entropylen, |
| drbg->max_entropylen, |
| prediction_resistance); |
| if (entropylen < drbg->min_entropylen |
| || entropylen > drbg->max_entropylen) { |
| RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ERROR_RETRIEVING_ENTROPY); |
| goto end; |
| } |
| |
| if (!drbg->meth->reseed(drbg, entropy, entropylen, adin, adinlen)) |
| goto end; |
| |
| drbg->state = DRBG_READY; |
| drbg->reseed_gen_counter = 1; |
| drbg->reseed_time = time(NULL); |
| tsan_store(&drbg->reseed_prop_counter, drbg->reseed_next_counter); |
| |
| end: |
| if (entropy != NULL && drbg->cleanup_entropy != NULL) |
| drbg->cleanup_entropy(drbg, entropy, entropylen); |
| if (drbg->state == DRBG_READY) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * 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. |
| */ |
| int rand_drbg_restart(RAND_DRBG *drbg, |
| const unsigned char *buffer, size_t len, size_t entropy) |
| { |
| int reseeded = 0; |
| const unsigned char *adin = NULL; |
| size_t adinlen = 0; |
| |
| if (drbg->seed_pool != NULL) { |
| RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR); |
| drbg->state = DRBG_ERROR; |
| rand_pool_free(drbg->seed_pool); |
| drbg->seed_pool = NULL; |
| return 0; |
| } |
| |
| if (buffer != NULL) { |
| if (entropy > 0) { |
| if (drbg->max_entropylen < len) { |
| RANDerr(RAND_F_RAND_DRBG_RESTART, |
| RAND_R_ENTROPY_INPUT_TOO_LONG); |
| drbg->state = DRBG_ERROR; |
| return 0; |
| } |
| |
| if (entropy > 8 * len) { |
| RANDerr(RAND_F_RAND_DRBG_RESTART, RAND_R_ENTROPY_OUT_OF_RANGE); |
| drbg->state = DRBG_ERROR; |
| return 0; |
| } |
| |
| /* will be picked up by the rand_drbg_get_entropy() callback */ |
| drbg->seed_pool = rand_pool_attach(buffer, len, entropy); |
| if (drbg->seed_pool == NULL) |
| return 0; |
| } else { |
| if (drbg->max_adinlen < len) { |
| RANDerr(RAND_F_RAND_DRBG_RESTART, |
| RAND_R_ADDITIONAL_INPUT_TOO_LONG); |
| drbg->state = DRBG_ERROR; |
| return 0; |
| } |
| adin = buffer; |
| adinlen = len; |
| } |
| } |
| |
| /* repair error state */ |
| if (drbg->state == DRBG_ERROR) |
| RAND_DRBG_uninstantiate(drbg); |
| |
| /* repair uninitialized state */ |
| if (drbg->state == DRBG_UNINITIALISED) { |
| /* reinstantiate drbg */ |
| RAND_DRBG_instantiate(drbg, |
| (const unsigned char *) ossl_pers_string, |
| sizeof(ossl_pers_string) - 1); |
| /* already reseeded. prevent second reseeding below */ |
| reseeded = (drbg->state == DRBG_READY); |
| } |
| |
| /* refresh current state if entropy or additional input has been provided */ |
| if (drbg->state == DRBG_READY) { |
| if (adin != NULL) { |
| /* |
| * mix in additional input without reseeding |
| * |
| * Similar to RAND_DRBG_reseed(), but the provided additional |
| * data |adin| is mixed into the current state without pulling |
| * entropy from the trusted entropy source using get_entropy(). |
| * This is not a reseeding in the strict sense of NIST SP 800-90A. |
| */ |
| drbg->meth->reseed(drbg, adin, adinlen, NULL, 0); |
| } else if (reseeded == 0) { |
| /* do a full reseeding if it has not been done yet above */ |
| RAND_DRBG_reseed(drbg, NULL, 0, 0); |
| } |
| } |
| |
| rand_pool_free(drbg->seed_pool); |
| drbg->seed_pool = NULL; |
| |
| return drbg->state == DRBG_READY; |
| } |
| |
| /* |
| * 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 RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen, |
| int prediction_resistance, |
| const unsigned char *adin, size_t adinlen) |
| { |
| int fork_id; |
| int reseed_required = 0; |
| |
| if (drbg->state != DRBG_READY) { |
| /* try to recover from previous errors */ |
| rand_drbg_restart(drbg, NULL, 0, 0); |
| |
| if (drbg->state == DRBG_ERROR) { |
| RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_IN_ERROR_STATE); |
| return 0; |
| } |
| if (drbg->state == DRBG_UNINITIALISED) { |
| RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_NOT_INSTANTIATED); |
| return 0; |
| } |
| } |
| |
| if (outlen > drbg->max_request) { |
| RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG); |
| return 0; |
| } |
| if (adinlen > drbg->max_adinlen) { |
| RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_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->reseed_gen_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) { |
| unsigned int reseed_counter = tsan_load(&drbg->reseed_prop_counter); |
| if (reseed_counter > 0 |
| && tsan_load(&drbg->parent->reseed_prop_counter) |
| != reseed_counter) |
| reseed_required = 1; |
| } |
| |
| if (reseed_required || prediction_resistance) { |
| if (!RAND_DRBG_reseed(drbg, adin, adinlen, prediction_resistance)) { |
| RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_RESEED_ERROR); |
| return 0; |
| } |
| adin = NULL; |
| adinlen = 0; |
| } |
| |
| if (!drbg->meth->generate(drbg, out, outlen, adin, adinlen)) { |
| drbg->state = DRBG_ERROR; |
| RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_GENERATE_ERROR); |
| return 0; |
| } |
| |
| drbg->reseed_gen_counter++; |
| |
| return 1; |
| } |
| |
| /* |
| * Generates |outlen| random bytes and stores them in |out|. It will |
| * using the given |drbg| to generate the bytes. |
| * |
| * Requires that drbg->lock is already locked for write, if non-null. |
| * |
| * Returns 1 on success 0 on failure. |
| */ |
| int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen) |
| { |
| unsigned char *additional = NULL; |
| size_t additional_len; |
| size_t chunk; |
| size_t ret = 0; |
| |
| if (drbg->adin_pool == NULL) { |
| if (drbg->type == 0) |
| goto err; |
| drbg->adin_pool = rand_pool_new(0, 0, 0, drbg->max_adinlen); |
| if (drbg->adin_pool == NULL) |
| goto err; |
| } |
| |
| additional_len = rand_drbg_get_additional_data(drbg->adin_pool, |
| &additional); |
| |
| for ( ; outlen > 0; outlen -= chunk, out += chunk) { |
| chunk = outlen; |
| if (chunk > drbg->max_request) |
| chunk = drbg->max_request; |
| ret = RAND_DRBG_generate(drbg, out, chunk, 0, additional, additional_len); |
| if (!ret) |
| goto err; |
| } |
| ret = 1; |
| |
| err: |
| if (additional != NULL) |
| rand_drbg_cleanup_additional_data(drbg->adin_pool, additional); |
| |
| return ret; |
| } |
| |
| /* |
| * Set the RAND_DRBG callbacks for obtaining entropy and nonce. |
| * |
| * Setting the callbacks is allowed only if the drbg has not been |
| * initialized yet. Otherwise, the operation will fail. |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int RAND_DRBG_set_callbacks(RAND_DRBG *drbg, |
| RAND_DRBG_get_entropy_fn get_entropy, |
| RAND_DRBG_cleanup_entropy_fn cleanup_entropy, |
| RAND_DRBG_get_nonce_fn get_nonce, |
| RAND_DRBG_cleanup_nonce_fn cleanup_nonce) |
| { |
| if (drbg->state != DRBG_UNINITIALISED |
| || drbg->parent != NULL) |
| return 0; |
| drbg->get_entropy = get_entropy; |
| drbg->cleanup_entropy = cleanup_entropy; |
| drbg->get_nonce = get_nonce; |
| drbg->cleanup_nonce = cleanup_nonce; |
| return 1; |
| } |
| |
| /* |
| * Set the reseed interval. |
| * |
| * The drbg will reseed automatically whenever the number of generate |
| * requests exceeds the given reseed interval. If the reseed interval |
| * is 0, then this feature is disabled. |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval) |
| { |
| if (interval > MAX_RESEED_INTERVAL) |
| return 0; |
| drbg->reseed_interval = interval; |
| return 1; |
| } |
| |
| /* |
| * Set the reseed time interval. |
| * |
| * The drbg will reseed automatically whenever the time elapsed since |
| * the last reseeding exceeds the given reseed time interval. For safety, |
| * a reseeding will also occur if the clock has been reset to a smaller |
| * value. |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval) |
| { |
| if (interval > MAX_RESEED_TIME_INTERVAL) |
| return 0; |
| drbg->reseed_time_interval = interval; |
| return 1; |
| } |
| |
| /* |
| * Set the default values for reseed (time) intervals of new DRBG instances |
| * |
| * The default values can be set independently for master DRBG instances |
| * (without a parent) and slave DRBG instances (with parent). |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| |
| int RAND_DRBG_set_reseed_defaults( |
| unsigned int _master_reseed_interval, |
| unsigned int _slave_reseed_interval, |
| time_t _master_reseed_time_interval, |
| time_t _slave_reseed_time_interval |
| ) |
| { |
| if (_master_reseed_interval > MAX_RESEED_INTERVAL |
| || _slave_reseed_interval > MAX_RESEED_INTERVAL) |
| return 0; |
| |
| if (_master_reseed_time_interval > MAX_RESEED_TIME_INTERVAL |
| || _slave_reseed_time_interval > MAX_RESEED_TIME_INTERVAL) |
| return 0; |
| |
| master_reseed_interval = _master_reseed_interval; |
| slave_reseed_interval = _slave_reseed_interval; |
| |
| master_reseed_time_interval = _master_reseed_time_interval; |
| slave_reseed_time_interval = _slave_reseed_time_interval; |
| |
| return 1; |
| } |
| |
| /* |
| * Locks the given drbg. Locking a drbg which does not have locking |
| * enabled is considered a successful no-op. |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int rand_drbg_lock(RAND_DRBG *drbg) |
| { |
| if (drbg->lock != NULL) |
| return CRYPTO_THREAD_write_lock(drbg->lock); |
| |
| return 1; |
| } |
| |
| /* |
| * Unlocks the given drbg. Unlocking a drbg which does not have locking |
| * enabled is considered a successful no-op. |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int rand_drbg_unlock(RAND_DRBG *drbg) |
| { |
| if (drbg->lock != NULL) |
| return CRYPTO_THREAD_unlock(drbg->lock); |
| |
| return 1; |
| } |
| |
| /* |
| * Enables locking for the given drbg |
| * |
| * Locking can only be enabled if the random generator |
| * is in the uninitialized state. |
| * |
| * Returns 1 on success, 0 on failure. |
| */ |
| int rand_drbg_enable_locking(RAND_DRBG *drbg) |
| { |
| if (drbg->state != DRBG_UNINITIALISED) { |
| RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, |
| RAND_R_DRBG_ALREADY_INITIALIZED); |
| return 0; |
| } |
| |
| if (drbg->lock == NULL) { |
| if (drbg->parent != NULL && drbg->parent->lock == NULL) { |
| RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, |
| RAND_R_PARENT_LOCKING_NOT_ENABLED); |
| return 0; |
| } |
| |
| drbg->lock = CRYPTO_THREAD_lock_new(); |
| if (drbg->lock == NULL) { |
| RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, |
| RAND_R_FAILED_TO_CREATE_LOCK); |
| return 0; |
| } |
| } |
| |
| return 1; |
| } |
| |
| /* |
| * Get and set the EXDATA |
| */ |
| int RAND_DRBG_set_ex_data(RAND_DRBG *drbg, int idx, void *arg) |
| { |
| return CRYPTO_set_ex_data(&drbg->ex_data, idx, arg); |
| } |
| |
| void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx) |
| { |
| return CRYPTO_get_ex_data(&drbg->ex_data, idx); |
| } |
| |
| |
| /* |
| * The following functions provide a RAND_METHOD that works on the |
| * global DRBG. They lock. |
| */ |
| |
| /* |
| * Allocates a new global DRBG on the secure heap (if enabled) and |
| * initializes it with default settings. |
| * |
| * Returns a pointer to the new DRBG instance on success, NULL on failure. |
| */ |
| static RAND_DRBG *drbg_setup(RAND_DRBG *parent) |
| { |
| RAND_DRBG *drbg; |
| |
| drbg = RAND_DRBG_secure_new(rand_drbg_type, rand_drbg_flags, parent); |
| if (drbg == NULL) |
| return NULL; |
| |
| /* Only the master DRBG needs to have a lock */ |
| if (parent == NULL && rand_drbg_enable_locking(drbg) == 0) |
| goto err; |
| |
| /* enable seed propagation */ |
| tsan_store(&drbg->reseed_prop_counter, 1); |
| |
| /* |
| * Ignore instantiation error to support just-in-time instantiation. |
| * |
| * The state of the drbg will be checked in RAND_DRBG_generate() and |
| * an automatic recovery is attempted. |
| */ |
| (void)RAND_DRBG_instantiate(drbg, |
| (const unsigned char *) ossl_pers_string, |
| sizeof(ossl_pers_string) - 1); |
| return drbg; |
| |
| err: |
| RAND_DRBG_free(drbg); |
| return NULL; |
| } |
| |
| /* |
| * Initialize the global DRBGs on first use. |
| * Returns 1 on success, 0 on failure. |
| */ |
| DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init) |
| { |
| /* |
| * ensure that libcrypto is initialized, otherwise the |
| * DRBG locks are not cleaned up properly |
| */ |
| if (!OPENSSL_init_crypto(0, NULL)) |
| return 0; |
| |
| if (!CRYPTO_THREAD_init_local(&private_drbg, NULL)) |
| return 0; |
| |
| if (!CRYPTO_THREAD_init_local(&public_drbg, NULL)) |
| goto err1; |
| |
| master_drbg = drbg_setup(NULL); |
| if (master_drbg == NULL) |
| goto err2; |
| |
| return 1; |
| |
| err2: |
| CRYPTO_THREAD_cleanup_local(&public_drbg); |
| err1: |
| CRYPTO_THREAD_cleanup_local(&private_drbg); |
| return 0; |
| } |
| |
| /* Clean up the global DRBGs before exit */ |
| void rand_drbg_cleanup_int(void) |
| { |
| if (master_drbg != NULL) { |
| RAND_DRBG_free(master_drbg); |
| master_drbg = NULL; |
| |
| CRYPTO_THREAD_cleanup_local(&private_drbg); |
| CRYPTO_THREAD_cleanup_local(&public_drbg); |
| } |
| } |
| |
| void drbg_delete_thread_state(void) |
| { |
| RAND_DRBG *drbg; |
| |
| drbg = CRYPTO_THREAD_get_local(&public_drbg); |
| CRYPTO_THREAD_set_local(&public_drbg, NULL); |
| RAND_DRBG_free(drbg); |
| |
| drbg = CRYPTO_THREAD_get_local(&private_drbg); |
| CRYPTO_THREAD_set_local(&private_drbg, NULL); |
| RAND_DRBG_free(drbg); |
| } |
| |
| /* Implements the default OpenSSL RAND_bytes() method */ |
| static int drbg_bytes(unsigned char *out, int count) |
| { |
| int ret; |
| RAND_DRBG *drbg = RAND_DRBG_get0_public(); |
| |
| if (drbg == NULL) |
| return 0; |
| |
| ret = RAND_DRBG_bytes(drbg, out, count); |
| |
| return ret; |
| } |
| |
| /* |
| * Calculates the minimum length of a full entropy buffer |
| * which is necessary to seed (i.e. instantiate) the DRBG |
| * successfully. |
| */ |
| size_t rand_drbg_seedlen(RAND_DRBG *drbg) |
| { |
| /* |
| * If no os entropy source is available then RAND_seed(buffer, bufsize) |
| * is expected to succeed if and only if the buffer length satisfies |
| * the following requirements, which follow from the calculations |
| * in RAND_DRBG_instantiate(). |
| */ |
| size_t min_entropy = drbg->strength; |
| size_t min_entropylen = drbg->min_entropylen; |
| |
| /* |
| * Extra entropy for the random nonce in the absence of a |
| * get_nonce callback, see comment in RAND_DRBG_instantiate(). |
| */ |
| if (drbg->min_noncelen > 0 && drbg->get_nonce == NULL) { |
| min_entropy += drbg->strength / 2; |
| min_entropylen += drbg->min_noncelen; |
| } |
| |
| /* |
| * Convert entropy requirement from bits to bytes |
| * (dividing by 8 without rounding upwards, because |
| * all entropy requirements are divisible by 8). |
| */ |
| min_entropy >>= 3; |
| |
| /* Return a value that satisfies both requirements */ |
| return min_entropy > min_entropylen ? min_entropy : min_entropylen; |
| } |
| |
| /* Implements the default OpenSSL RAND_add() method */ |
| static int drbg_add(const void *buf, int num, double randomness) |
| { |
| int ret = 0; |
| RAND_DRBG *drbg = RAND_DRBG_get0_master(); |
| size_t buflen; |
| size_t seedlen; |
| |
| if (drbg == NULL) |
| return 0; |
| |
| if (num < 0 || randomness < 0.0) |
| return 0; |
| |
| rand_drbg_lock(drbg); |
| seedlen = rand_drbg_seedlen(drbg); |
| |
| buflen = (size_t)num; |
| |
| if (buflen < seedlen || randomness < (double) seedlen) { |
| #if defined(OPENSSL_RAND_SEED_NONE) |
| /* |
| * If no os entropy source is available, a reseeding will fail |
| * inevitably. So we use a trick to mix the buffer contents into |
| * the DRBG state without forcing a reseeding: we generate a |
| * dummy random byte, using the buffer content as additional data. |
| * Note: This won't work with RAND_DRBG_FLAG_CTR_NO_DF. |
| */ |
| unsigned char dummy[1]; |
| |
| ret = RAND_DRBG_generate(drbg, dummy, sizeof(dummy), 0, buf, buflen); |
| rand_drbg_unlock(drbg); |
| return ret; |
| #else |
| /* |
| * If an os entropy source is available then we declare the buffer content |
| * as additional data by setting randomness to zero and trigger a regular |
| * reseeding. |
| */ |
| randomness = 0.0; |
| #endif |
| } |
| |
| |
| if (randomness > (double)seedlen) { |
| /* |
| * The purpose of this check is to bound |randomness| by a |
| * relatively small value in order to prevent an integer |
| * overflow when multiplying by 8 in the rand_drbg_restart() |
| * call below. Note that randomness is measured in bytes, |
| * not bits, so this value corresponds to eight times the |
| * security strength. |
| */ |
| randomness = (double)seedlen; |
| } |
| |
| ret = rand_drbg_restart(drbg, buf, buflen, (size_t)(8 * randomness)); |
| rand_drbg_unlock(drbg); |
| |
| return ret; |
| } |
| |
| /* Implements the default OpenSSL RAND_seed() method */ |
| static int drbg_seed(const void *buf, int num) |
| { |
| return drbg_add(buf, num, num); |
| } |
| |
| /* Implements the default OpenSSL RAND_status() method */ |
| static int drbg_status(void) |
| { |
| int ret; |
| RAND_DRBG *drbg = RAND_DRBG_get0_master(); |
| |
| if (drbg == NULL) |
| return 0; |
| |
| rand_drbg_lock(drbg); |
| ret = drbg->state == DRBG_READY ? 1 : 0; |
| rand_drbg_unlock(drbg); |
| return ret; |
| } |
| |
| /* |
| * Get the master DRBG. |
| * Returns pointer to the DRBG on success, NULL on failure. |
| * |
| */ |
| RAND_DRBG *RAND_DRBG_get0_master(void) |
| { |
| if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) |
| return NULL; |
| |
| return master_drbg; |
| } |
| |
| /* |
| * Get the public DRBG. |
| * Returns pointer to the DRBG on success, NULL on failure. |
| */ |
| RAND_DRBG *RAND_DRBG_get0_public(void) |
| { |
| RAND_DRBG *drbg; |
| |
| if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) |
| return NULL; |
| |
| drbg = CRYPTO_THREAD_get_local(&public_drbg); |
| if (drbg == NULL) { |
| if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND)) |
| return NULL; |
| drbg = drbg_setup(master_drbg); |
| CRYPTO_THREAD_set_local(&public_drbg, drbg); |
| } |
| return drbg; |
| } |
| |
| /* |
| * Get the private DRBG. |
| * Returns pointer to the DRBG on success, NULL on failure. |
| */ |
| RAND_DRBG *RAND_DRBG_get0_private(void) |
| { |
| RAND_DRBG *drbg; |
| |
| if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) |
| return NULL; |
| |
| drbg = CRYPTO_THREAD_get_local(&private_drbg); |
| if (drbg == NULL) { |
| if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND)) |
| return NULL; |
| drbg = drbg_setup(master_drbg); |
| CRYPTO_THREAD_set_local(&private_drbg, drbg); |
| } |
| return drbg; |
| } |
| |
| RAND_METHOD rand_meth = { |
| drbg_seed, |
| drbg_bytes, |
| NULL, |
| drbg_add, |
| drbg_bytes, |
| drbg_status |
| }; |
| |
| RAND_METHOD *RAND_OpenSSL(void) |
| { |
| return &rand_meth; |
| } |
