| /* |
| * Copyright 1995-2020 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 <stdio.h> |
| #include <time.h> |
| #include "internal/cryptlib.h" |
| #include <openssl/opensslconf.h> |
| #include "crypto/rand.h" |
| #include <openssl/engine.h> |
| #include "internal/thread_once.h" |
| #include "rand_local.h" |
| #include "e_os.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 CRYPTO_RWLOCK *rand_nonce_lock; |
| static int rand_nonce_count; |
| |
| static int rand_inited = 0; |
| |
| #ifdef OPENSSL_RAND_SEED_RDTSC |
| /* |
| * IMPORTANT NOTE: It is not currently possible to use this code |
| * because we are not sure about the amount of randomness it provides. |
| * Some SP900 tests have been run, but there is internal skepticism. |
| * So for now this code is not used. |
| */ |
| # error "RDTSC enabled? Should not be possible!" |
| |
| /* |
| * Acquire entropy from high-speed clock |
| * |
| * Since we get some randomness from the low-order bits of the |
| * high-speed clock, it can help. |
| * |
| * Returns the total entropy count, if it exceeds the requested |
| * entropy count. Otherwise, returns an entropy count of 0. |
| */ |
| size_t rand_acquire_entropy_from_tsc(RAND_POOL *pool) |
| { |
| unsigned char c; |
| int i; |
| |
| if ((OPENSSL_ia32cap_P[0] & (1 << 4)) != 0) { |
| for (i = 0; i < TSC_READ_COUNT; i++) { |
| c = (unsigned char)(OPENSSL_rdtsc() & 0xFF); |
| rand_pool_add(pool, &c, 1, 4); |
| } |
| } |
| return rand_pool_entropy_available(pool); |
| } |
| #endif |
| |
| #ifdef OPENSSL_RAND_SEED_RDCPU |
| size_t OPENSSL_ia32_rdseed_bytes(unsigned char *buf, size_t len); |
| size_t OPENSSL_ia32_rdrand_bytes(unsigned char *buf, size_t len); |
| |
| extern unsigned int OPENSSL_ia32cap_P[]; |
| |
| /* |
| * Acquire entropy using Intel-specific cpu instructions |
| * |
| * Uses the RDSEED instruction if available, otherwise uses |
| * RDRAND if available. |
| * |
| * For the differences between RDSEED and RDRAND, and why RDSEED |
| * is the preferred choice, see https://goo.gl/oK3KcN |
| * |
| * Returns the total entropy count, if it exceeds the requested |
| * entropy count. Otherwise, returns an entropy count of 0. |
| */ |
| size_t rand_acquire_entropy_from_cpu(RAND_POOL *pool) |
| { |
| size_t bytes_needed; |
| unsigned char *buffer; |
| |
| bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/); |
| if (bytes_needed > 0) { |
| buffer = rand_pool_add_begin(pool, bytes_needed); |
| |
| if (buffer != NULL) { |
| /* Whichever comes first, use RDSEED, RDRAND or nothing */ |
| if ((OPENSSL_ia32cap_P[2] & (1 << 18)) != 0) { |
| if (OPENSSL_ia32_rdseed_bytes(buffer, bytes_needed) |
| == bytes_needed) { |
| rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed); |
| } |
| } else if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) { |
| if (OPENSSL_ia32_rdrand_bytes(buffer, bytes_needed) |
| == bytes_needed) { |
| rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed); |
| } |
| } else { |
| rand_pool_add_end(pool, 0, 0); |
| } |
| } |
| } |
| |
| return rand_pool_entropy_available(pool); |
| } |
| #endif |
| |
| |
| /* |
| * Implements the get_entropy() callback (see RAND_DRBG_set_callbacks()) |
| * |
| * If the DRBG has a parent, then the required amount of entropy input |
| * is fetched using the parent's RAND_DRBG_generate(). |
| * |
| * Otherwise, the entropy is polled from the system entropy sources |
| * using rand_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 rand_drbg_get_entropy(RAND_DRBG *drbg, |
| unsigned char **pout, |
| int entropy, size_t min_len, size_t max_len, |
| int prediction_resistance) |
| { |
| size_t ret = 0; |
| size_t entropy_available = 0; |
| RAND_POOL *pool; |
| |
| if (drbg->parent != NULL && drbg->strength > drbg->parent->strength) { |
| /* |
| * We currently don't support the algorithm from NIST SP 800-90C |
| * 10.1.2 to use a weaker DRBG as source |
| */ |
| RANDerr(RAND_F_RAND_DRBG_GET_ENTROPY, RAND_R_PARENT_STRENGTH_TOO_WEAK); |
| return 0; |
| } |
| |
| if (drbg->seed_pool != NULL) { |
| pool = drbg->seed_pool; |
| pool->entropy_requested = entropy; |
| } else { |
| pool = rand_pool_new(entropy, drbg->secure, min_len, max_len); |
| if (pool == NULL) |
| return 0; |
| } |
| |
| if (drbg->parent != NULL) { |
| size_t bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/); |
| unsigned char *buffer = rand_pool_add_begin(pool, bytes_needed); |
| |
| if (buffer != NULL) { |
| size_t bytes = 0; |
| |
| /* |
| * Get random data from parent. Include our address as additional input, |
| * in order to provide some additional distinction between different |
| * DRBG child instances. |
| * 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 if drbg->parent->lock == NULL.) |
| */ |
| rand_drbg_lock(drbg->parent); |
| if (RAND_DRBG_generate(drbg->parent, |
| buffer, bytes_needed, |
| prediction_resistance, |
| (unsigned char *)&drbg, sizeof(drbg)) != 0) |
| bytes = bytes_needed; |
| rand_drbg_unlock(drbg->parent); |
| |
| rand_pool_add_end(pool, bytes, 8 * bytes); |
| entropy_available = rand_pool_entropy_available(pool); |
| } |
| |
| } else { |
| if (prediction_resistance) { |
| /* |
| * We don't have any entropy sources that comply with the NIST |
| * standard to provide prediction resistance (see NIST SP 800-90C, |
| * Section 5.4). |
| */ |
| RANDerr(RAND_F_RAND_DRBG_GET_ENTROPY, |
| RAND_R_PREDICTION_RESISTANCE_NOT_SUPPORTED); |
| goto err; |
| } |
| |
| /* Get entropy by polling system entropy sources. */ |
| entropy_available = rand_pool_acquire_entropy(pool); |
| } |
| |
| if (entropy_available > 0) { |
| ret = rand_pool_length(pool); |
| *pout = rand_pool_detach(pool); |
| } |
| |
| err: |
| if (drbg->seed_pool == NULL) |
| rand_pool_free(pool); |
| return ret; |
| } |
| |
| /* |
| * Implements the cleanup_entropy() callback (see RAND_DRBG_set_callbacks()) |
| * |
| */ |
| void rand_drbg_cleanup_entropy(RAND_DRBG *drbg, |
| unsigned char *out, size_t outlen) |
| { |
| if (drbg->seed_pool == NULL) { |
| if (drbg->secure) |
| OPENSSL_secure_clear_free(out, outlen); |
| else |
| OPENSSL_clear_free(out, outlen); |
| } |
| } |
| |
| |
| /* |
| * Implements the get_nonce() callback (see RAND_DRBG_set_callbacks()) |
| * |
| */ |
| size_t rand_drbg_get_nonce(RAND_DRBG *drbg, |
| unsigned char **pout, |
| int entropy, size_t min_len, size_t max_len) |
| { |
| size_t ret = 0; |
| RAND_POOL *pool; |
| |
| struct { |
| void * instance; |
| int count; |
| } data; |
| |
| memset(&data, 0, sizeof(data)); |
| pool = rand_pool_new(0, 0, min_len, max_len); |
| if (pool == NULL) |
| return 0; |
| |
| if (rand_pool_add_nonce_data(pool) == 0) |
| goto err; |
| |
| data.instance = drbg; |
| CRYPTO_atomic_add(&rand_nonce_count, 1, &data.count, rand_nonce_lock); |
| |
| if (rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0) == 0) |
| goto err; |
| |
| ret = rand_pool_length(pool); |
| *pout = rand_pool_detach(pool); |
| |
| err: |
| rand_pool_free(pool); |
| |
| return ret; |
| } |
| |
| /* |
| * Implements the cleanup_nonce() callback (see RAND_DRBG_set_callbacks()) |
| * |
| */ |
| void rand_drbg_cleanup_nonce(RAND_DRBG *drbg, |
| unsigned char *out, size_t outlen) |
| { |
| OPENSSL_clear_free(out, outlen); |
| } |
| |
| /* |
| * Generate additional data that can be used for the drbg. The data does |
| * not need to contain entropy, but it's useful if it contains at least |
| * some bits that are unpredictable. |
| * |
| * Returns 0 on failure. |
| * |
| * On success it allocates a buffer at |*pout| and returns the length of |
| * the data. The buffer should get freed using OPENSSL_secure_clear_free(). |
| */ |
| size_t rand_drbg_get_additional_data(RAND_POOL *pool, unsigned char **pout) |
| { |
| size_t ret = 0; |
| |
| if (rand_pool_add_additional_data(pool) == 0) |
| goto err; |
| |
| ret = rand_pool_length(pool); |
| *pout = rand_pool_detach(pool); |
| |
| err: |
| return ret; |
| } |
| |
| void rand_drbg_cleanup_additional_data(RAND_POOL *pool, unsigned char *out) |
| { |
| rand_pool_reattach(pool, out); |
| } |
| |
| 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 err1; |
| |
| rand_nonce_lock = CRYPTO_THREAD_lock_new(); |
| if (rand_nonce_lock == NULL) |
| goto err2; |
| |
| if (!rand_pool_init()) |
| goto err3; |
| |
| rand_inited = 1; |
| return 1; |
| |
| err3: |
| CRYPTO_THREAD_lock_free(rand_nonce_lock); |
| rand_nonce_lock = NULL; |
| err2: |
| CRYPTO_THREAD_lock_free(rand_meth_lock); |
| rand_meth_lock = NULL; |
| err1: |
| #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; |
| CRYPTO_THREAD_lock_free(rand_nonce_lock); |
| rand_nonce_lock = NULL; |
| rand_inited = 0; |
| } |
| |
| /* |
| * RAND_close_seed_files() ensures that any seed file descriptors are |
| * closed after use. |
| */ |
| 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) |
| { |
| int ret = 0; |
| |
| RAND_POOL *pool = NULL; |
| |
| const RAND_METHOD *meth = RAND_get_rand_method(); |
| |
| if (meth == NULL) |
| return 0; |
| |
| if (meth == RAND_OpenSSL()) { |
| /* fill random pool and seed the master DRBG */ |
| RAND_DRBG *drbg = RAND_DRBG_get0_master(); |
| |
| if (drbg == NULL) |
| return 0; |
| |
| rand_drbg_lock(drbg); |
| ret = rand_drbg_restart(drbg, NULL, 0, 0); |
| rand_drbg_unlock(drbg); |
| |
| return ret; |
| |
| } else { |
| /* fill random pool and seed the current legacy RNG */ |
| pool = rand_pool_new(RAND_DRBG_STRENGTH, 1, |
| (RAND_DRBG_STRENGTH + 7) / 8, |
| RAND_POOL_MAX_LENGTH); |
| if (pool == NULL) |
| return 0; |
| |
| if (rand_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); |
| return ret; |
| } |
| |
| /* |
| * Allocate memory and initialize a new random pool |
| */ |
| |
| RAND_POOL *rand_pool_new(int entropy_requested, int secure, |
| size_t min_len, size_t max_len) |
| { |
| RAND_POOL *pool; |
| size_t min_alloc_size = RAND_POOL_MIN_ALLOCATION(secure); |
| |
| if (!RUN_ONCE(&rand_init, do_rand_init)) |
| return NULL; |
| |
| pool = OPENSSL_zalloc(sizeof(*pool)); |
| if (pool == NULL) { |
| RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE); |
| return NULL; |
| } |
| |
| pool->min_len = min_len; |
| pool->max_len = (max_len > RAND_POOL_MAX_LENGTH) ? |
| RAND_POOL_MAX_LENGTH : max_len; |
| pool->alloc_len = min_len < min_alloc_size ? min_alloc_size : min_len; |
| if (pool->alloc_len > pool->max_len) |
| pool->alloc_len = pool->max_len; |
| |
| if (secure) |
| pool->buffer = OPENSSL_secure_zalloc(pool->alloc_len); |
| else |
| pool->buffer = OPENSSL_zalloc(pool->alloc_len); |
| |
| if (pool->buffer == NULL) { |
| RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| |
| pool->entropy_requested = entropy_requested; |
| pool->secure = secure; |
| |
| return pool; |
| |
| err: |
| OPENSSL_free(pool); |
| return NULL; |
| } |
| |
| /* |
| * Attach new random pool to the given buffer |
| * |
| * This function is intended to be used only for feeding random data |
| * provided by RAND_add() and RAND_seed() into the <master> DRBG. |
| */ |
| RAND_POOL *rand_pool_attach(const unsigned char *buffer, size_t len, |
| size_t entropy) |
| { |
| RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool)); |
| |
| if (pool == NULL) { |
| RANDerr(RAND_F_RAND_POOL_ATTACH, ERR_R_MALLOC_FAILURE); |
| return NULL; |
| } |
| |
| /* |
| * The const needs to be cast away, but attached buffers will not be |
| * modified (in contrary to allocated buffers which are zeroed and |
| * freed in the end). |
| */ |
| pool->buffer = (unsigned char *) buffer; |
| pool->len = len; |
| |
| pool->attached = 1; |
| |
| pool->min_len = pool->max_len = pool->alloc_len = pool->len; |
| pool->entropy = entropy; |
| |
| return pool; |
| } |
| |
| /* |
| * Free |pool|, securely erasing its buffer. |
| */ |
| void rand_pool_free(RAND_POOL *pool) |
| { |
| if (pool == NULL) |
| return; |
| |
| /* |
| * Although it would be advisable from a cryptographical viewpoint, |
| * we are not allowed to clear attached buffers, since they are passed |
| * to rand_pool_attach() as `const unsigned char*`. |
| * (see corresponding comment in rand_pool_attach()). |
| */ |
| if (!pool->attached) { |
| if (pool->secure) |
| OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len); |
| else |
| OPENSSL_clear_free(pool->buffer, pool->alloc_len); |
| } |
| |
| OPENSSL_free(pool); |
| } |
| |
| /* |
| * Return the |pool|'s buffer to the caller (readonly). |
| */ |
| const unsigned char *rand_pool_buffer(RAND_POOL *pool) |
| { |
| return pool->buffer; |
| } |
| |
| /* |
| * Return the |pool|'s entropy to the caller. |
| */ |
| size_t rand_pool_entropy(RAND_POOL *pool) |
| { |
| return pool->entropy; |
| } |
| |
| /* |
| * Return the |pool|'s buffer length to the caller. |
| */ |
| size_t rand_pool_length(RAND_POOL *pool) |
| { |
| return pool->len; |
| } |
| |
| /* |
| * Detach the |pool| buffer and return it to the caller. |
| * It's the responsibility of the caller to free the buffer |
| * using OPENSSL_secure_clear_free() or to re-attach it |
| * again to the pool using rand_pool_reattach(). |
| */ |
| unsigned char *rand_pool_detach(RAND_POOL *pool) |
| { |
| unsigned char *ret = pool->buffer; |
| pool->buffer = NULL; |
| pool->entropy = 0; |
| return ret; |
| } |
| |
| /* |
| * Re-attach the |pool| buffer. It is only allowed to pass |
| * the |buffer| which was previously detached from the same pool. |
| */ |
| void rand_pool_reattach(RAND_POOL *pool, unsigned char *buffer) |
| { |
| pool->buffer = buffer; |
| OPENSSL_cleanse(pool->buffer, pool->len); |
| pool->len = 0; |
| } |
| |
| /* |
| * If |entropy_factor| bits contain 1 bit of entropy, how many bytes does one |
| * need to obtain at least |bits| bits of entropy? |
| */ |
| #define ENTROPY_TO_BYTES(bits, entropy_factor) \ |
| (((bits) * (entropy_factor) + 7) / 8) |
| |
| |
| /* |
| * Checks whether the |pool|'s entropy is available to the caller. |
| * This is the case when entropy count and buffer length are high enough. |
| * Returns |
| * |
| * |entropy| if the entropy count and buffer size is large enough |
| * 0 otherwise |
| */ |
| size_t rand_pool_entropy_available(RAND_POOL *pool) |
| { |
| if (pool->entropy < pool->entropy_requested) |
| return 0; |
| |
| if (pool->len < pool->min_len) |
| return 0; |
| |
| return pool->entropy; |
| } |
| |
| /* |
| * Returns the (remaining) amount of entropy needed to fill |
| * the random pool. |
| */ |
| |
| size_t rand_pool_entropy_needed(RAND_POOL *pool) |
| { |
| if (pool->entropy < pool->entropy_requested) |
| return pool->entropy_requested - pool->entropy; |
| |
| return 0; |
| } |
| |
| /* Increase the allocation size -- not usable for an attached pool */ |
| static int rand_pool_grow(RAND_POOL *pool, size_t len) |
| { |
| if (len > pool->alloc_len - pool->len) { |
| unsigned char *p; |
| const size_t limit = pool->max_len / 2; |
| size_t newlen = pool->alloc_len; |
| |
| if (pool->attached || len > pool->max_len - pool->len) { |
| RANDerr(RAND_F_RAND_POOL_GROW, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| |
| do |
| newlen = newlen < limit ? newlen * 2 : pool->max_len; |
| while (len > newlen - pool->len); |
| |
| if (pool->secure) |
| p = OPENSSL_secure_zalloc(newlen); |
| else |
| p = OPENSSL_zalloc(newlen); |
| if (p == NULL) { |
| RANDerr(RAND_F_RAND_POOL_GROW, ERR_R_MALLOC_FAILURE); |
| return 0; |
| } |
| memcpy(p, pool->buffer, pool->len); |
| if (pool->secure) |
| OPENSSL_secure_clear_free(pool->buffer, pool->alloc_len); |
| else |
| OPENSSL_clear_free(pool->buffer, pool->alloc_len); |
| pool->buffer = p; |
| pool->alloc_len = newlen; |
| } |
| return 1; |
| } |
| |
| /* |
| * Returns the number of bytes needed to fill the pool, assuming |
| * the input has 1 / |entropy_factor| entropy bits per data bit. |
| * In case of an error, 0 is returned. |
| */ |
| |
| size_t rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_factor) |
| { |
| size_t bytes_needed; |
| size_t entropy_needed = rand_pool_entropy_needed(pool); |
| |
| if (entropy_factor < 1) { |
| RANDerr(RAND_F_RAND_POOL_BYTES_NEEDED, RAND_R_ARGUMENT_OUT_OF_RANGE); |
| return 0; |
| } |
| |
| bytes_needed = ENTROPY_TO_BYTES(entropy_needed, entropy_factor); |
| |
| if (bytes_needed > pool->max_len - pool->len) { |
| /* not enough space left */ |
| RANDerr(RAND_F_RAND_POOL_BYTES_NEEDED, RAND_R_RANDOM_POOL_OVERFLOW); |
| return 0; |
| } |
| |
| if (pool->len < pool->min_len && |
| bytes_needed < pool->min_len - pool->len) |
| /* to meet the min_len requirement */ |
| bytes_needed = pool->min_len - pool->len; |
| |
| /* |
| * Make sure the buffer is large enough for the requested amount |
| * of data. This guarantees that existing code patterns where |
| * rand_pool_add_begin, rand_pool_add_end or rand_pool_add |
| * are used to collect entropy data without any error handling |
| * whatsoever, continue to be valid. |
| * Furthermore if the allocation here fails once, make sure that |
| * we don't fall back to a less secure or even blocking random source, |
| * as that could happen by the existing code patterns. |
| * This is not a concern for additional data, therefore that |
| * is not needed if rand_pool_grow fails in other places. |
| */ |
| if (!rand_pool_grow(pool, bytes_needed)) { |
| /* persistent error for this pool */ |
| pool->max_len = pool->len = 0; |
| return 0; |
| } |
| |
| return bytes_needed; |
| } |
| |
| /* Returns the remaining number of bytes available */ |
| size_t rand_pool_bytes_remaining(RAND_POOL *pool) |
| { |
| return pool->max_len - pool->len; |
| } |
| |
| /* |
| * Add random bytes to the random pool. |
| * |
| * It is expected that the |buffer| contains |len| bytes of |
| * random input which contains at least |entropy| bits of |
| * randomness. |
| * |
| * Returns 1 if the added amount is adequate, otherwise 0 |
| */ |
| int rand_pool_add(RAND_POOL *pool, |
| const unsigned char *buffer, size_t len, size_t entropy) |
| { |
| if (len > pool->max_len - pool->len) { |
| RANDerr(RAND_F_RAND_POOL_ADD, RAND_R_ENTROPY_INPUT_TOO_LONG); |
| return 0; |
| } |
| |
| if (pool->buffer == NULL) { |
| RANDerr(RAND_F_RAND_POOL_ADD, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| |
| if (len > 0) { |
| /* |
| * This is to protect us from accidentally passing the buffer |
| * returned from rand_pool_add_begin. |
| * The check for alloc_len makes sure we do not compare the |
| * address of the end of the allocated memory to something |
| * different, since that comparison would have an |
| * indeterminate result. |
| */ |
| if (pool->alloc_len > pool->len && pool->buffer + pool->len == buffer) { |
| RANDerr(RAND_F_RAND_POOL_ADD, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| /* |
| * We have that only for cases when a pool is used to collect |
| * additional data. |
| * For entropy data, as long as the allocation request stays within |
| * the limits given by rand_pool_bytes_needed this rand_pool_grow |
| * below is guaranteed to succeed, thus no allocation happens. |
| */ |
| if (!rand_pool_grow(pool, len)) |
| return 0; |
| memcpy(pool->buffer + pool->len, buffer, len); |
| pool->len += len; |
| pool->entropy += entropy; |
| } |
| |
| return 1; |
| } |
| |
| /* |
| * Start to add random bytes to the random pool in-place. |
| * |
| * Reserves the next |len| bytes for adding random bytes in-place |
| * and returns a pointer to the buffer. |
| * The caller is allowed to copy up to |len| bytes into the buffer. |
| * If |len| == 0 this is considered a no-op and a NULL pointer |
| * is returned without producing an error message. |
| * |
| * After updating the buffer, rand_pool_add_end() needs to be called |
| * to finish the update operation (see next comment). |
| */ |
| unsigned char *rand_pool_add_begin(RAND_POOL *pool, size_t len) |
| { |
| if (len == 0) |
| return NULL; |
| |
| if (len > pool->max_len - pool->len) { |
| RANDerr(RAND_F_RAND_POOL_ADD_BEGIN, RAND_R_RANDOM_POOL_OVERFLOW); |
| return NULL; |
| } |
| |
| if (pool->buffer == NULL) { |
| RANDerr(RAND_F_RAND_POOL_ADD_BEGIN, ERR_R_INTERNAL_ERROR); |
| return NULL; |
| } |
| |
| /* |
| * As long as the allocation request stays within the limits given |
| * by rand_pool_bytes_needed this rand_pool_grow below is guaranteed |
| * to succeed, thus no allocation happens. |
| * We have that only for cases when a pool is used to collect |
| * additional data. Then the buffer might need to grow here, |
| * and of course the caller is responsible to check the return |
| * value of this function. |
| */ |
| if (!rand_pool_grow(pool, len)) |
| return NULL; |
| |
| return pool->buffer + pool->len; |
| } |
| |
| /* |
| * Finish to add random bytes to the random pool in-place. |
| * |
| * Finishes an in-place update of the random pool started by |
| * rand_pool_add_begin() (see previous comment). |
| * It is expected that |len| bytes of random input have been added |
| * to the buffer which contain at least |entropy| bits of randomness. |
| * It is allowed to add less bytes than originally reserved. |
| */ |
| int rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy) |
| { |
| if (len > pool->alloc_len - pool->len) { |
| RANDerr(RAND_F_RAND_POOL_ADD_END, RAND_R_RANDOM_POOL_OVERFLOW); |
| return 0; |
| } |
| |
| if (len > 0) { |
| pool->len += len; |
| pool->entropy += entropy; |
| } |
| |
| return 1; |
| } |
| |
| 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; |
| } |
| |
| #ifndef 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); |
| } |
| |
| /* |
| * 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(unsigned char *buf, int num) |
| { |
| const RAND_METHOD *meth = RAND_get_rand_method(); |
| RAND_DRBG *drbg; |
| |
| if (meth != NULL && meth != RAND_OpenSSL()) |
| return RAND_bytes(buf, num); |
| |
| drbg = RAND_DRBG_get0_private(); |
| if (drbg != NULL) |
| return RAND_DRBG_bytes(drbg, buf, num); |
| |
| return 0; |
| } |
| |
| int RAND_bytes(unsigned char *buf, int num) |
| { |
| const RAND_METHOD *meth = RAND_get_rand_method(); |
| |
| if (meth != NULL && meth->bytes != NULL) |
| return meth->bytes(buf, num); |
| RANDerr(RAND_F_RAND_BYTES, RAND_R_FUNC_NOT_IMPLEMENTED); |
| return -1; |
| } |
| |
| #if OPENSSL_API_COMPAT < 0x10100000L |
| 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); |
| RANDerr(RAND_F_RAND_PSEUDO_BYTES, RAND_R_FUNC_NOT_IMPLEMENTED); |
| return -1; |
| } |
| #endif |
| |
| int RAND_status(void) |
| { |
| const RAND_METHOD *meth = RAND_get_rand_method(); |
| |
| if (meth != NULL && meth->status != NULL) |
| return meth->status(); |
| return 0; |
| } |