| /* |
| * Copyright 1995-2017 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 "internal/rand_int.h" |
| #include <openssl/engine.h> |
| #include "internal/thread_once.h" |
| #include "rand_lcl.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; |
| RAND_BYTES_BUFFER rand_bytes; |
| int rand_fork_count; |
| |
| #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!" |
| |
| /* |
| * Since we get some randomness from the low-order bits of the |
| * high-speec clock, it can help. But don't return a status since |
| * it's not sufficient to indicate whether or not the seeding was |
| * done. |
| */ |
| void rand_read_tsc(RAND_poll_cb rand_add, void *arg) |
| { |
| 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_add(arg, &c, 1, 0.5); |
| } |
| } |
| } |
| #endif |
| |
| #ifdef OPENSSL_RAND_SEED_RDCPU |
| size_t OPENSSL_ia32_rdseed_bytes(char *buf, size_t len); |
| size_t OPENSSL_ia32_rdrand_bytes(char *buf, size_t len); |
| |
| extern unsigned int OPENSSL_ia32cap_P[]; |
| |
| int rand_read_cpu(RAND_poll_cb rand_add, void *arg) |
| { |
| char buff[RANDOMNESS_NEEDED]; |
| |
| /* If RDSEED is available, use that. */ |
| if ((OPENSSL_ia32cap_P[2] & (1 << 18)) != 0) { |
| if (OPENSSL_ia32_rdseed_bytes(buff, sizeof(buff)) == sizeof(buff)) { |
| rand_add(arg, buff, (int)sizeof(buff), sizeof(buff)); |
| return 1; |
| } |
| } |
| |
| /* Second choice is RDRAND. */ |
| if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) { |
| if (OPENSSL_ia32_rdrand_bytes(buff, sizeof(buff)) == sizeof(buff)) { |
| rand_add(arg, buff, (int)sizeof(buff), sizeof(buff)); |
| return 1; |
| } |
| } |
| |
| return 0; |
| } |
| #endif |
| |
| |
| /* |
| * DRBG has two sets of callbacks; we only discuss the "entropy" one |
| * here. When the DRBG needs additional randomness bits (called entropy |
| * in the NIST document), it calls the get_entropy callback which fills in |
| * a pointer and returns the number of bytes. When the DRBG is finished with |
| * the buffer, it calls the cleanup_entropy callback, with the value of |
| * the buffer that the get_entropy callback filled in. |
| * |
| * Get entropy from the system, via RAND_poll if needed. The |entropy| |
| * is the bits of randomness required, and is expected to fit into a buffer |
| * of |min_len|..|max__len| size. We assume we're getting high-quality |
| * randomness from the system, and that |min_len| bytes will do. |
| */ |
| size_t drbg_entropy_from_system(RAND_DRBG *drbg, |
| unsigned char **pout, |
| int entropy, size_t min_len, size_t max_len) |
| { |
| int i; |
| unsigned char *randomness; |
| |
| if (min_len > (size_t)drbg->size) { |
| /* Should not happen. See comment near RANDOMNESS_NEEDED. */ |
| min_len = drbg->size; |
| } |
| |
| randomness = drbg->secure ? OPENSSL_secure_malloc(drbg->size) |
| : OPENSSL_malloc(drbg->size); |
| |
| /* If we don't have enough, try to get more. */ |
| CRYPTO_THREAD_write_lock(rand_bytes.lock); |
| for (i = RAND_POLL_RETRIES; rand_bytes.curr < min_len && --i >= 0; ) { |
| CRYPTO_THREAD_unlock(rand_bytes.lock); |
| RAND_poll(); |
| CRYPTO_THREAD_write_lock(rand_bytes.lock); |
| } |
| |
| /* Get desired amount, but no more than we have. */ |
| if (min_len > rand_bytes.curr) |
| min_len = rand_bytes.curr; |
| if (min_len != 0) { |
| memcpy(randomness, rand_bytes.buff, min_len); |
| /* Update amount left and shift it down. */ |
| rand_bytes.curr -= min_len; |
| if (rand_bytes.curr != 0) |
| memmove(rand_bytes.buff, &rand_bytes.buff[min_len], rand_bytes.curr); |
| } |
| CRYPTO_THREAD_unlock(rand_bytes.lock); |
| *pout = randomness; |
| return min_len; |
| } |
| |
| size_t drbg_entropy_from_parent(RAND_DRBG *drbg, |
| unsigned char **pout, |
| int entropy, size_t min_len, size_t max_len) |
| { |
| int st; |
| unsigned char *randomness; |
| |
| if (min_len > (size_t)drbg->size) { |
| /* Should not happen. See comment near RANDOMNESS_NEEDED. */ |
| min_len = drbg->size; |
| } |
| |
| randomness = drbg->secure ? OPENSSL_secure_malloc(drbg->size) |
| : OPENSSL_malloc(drbg->size); |
| |
| /* Get random from parent, include our state as additional input. */ |
| st = RAND_DRBG_generate(drbg->parent, randomness, min_len, 0, |
| (unsigned char *)drbg, sizeof(*drbg)); |
| if (st == 0) { |
| drbg_release_entropy(drbg, randomness, min_len); |
| return 0; |
| } |
| *pout = randomness; |
| return min_len; |
| } |
| |
| void drbg_release_entropy(RAND_DRBG *drbg, unsigned char *out, size_t outlen) |
| { |
| if (drbg->secure) |
| OPENSSL_secure_clear_free(out, outlen); |
| else |
| OPENSSL_clear_free(out, outlen); |
| } |
| |
| void rand_fork() |
| { |
| rand_fork_count++; |
| } |
| |
| DEFINE_RUN_ONCE_STATIC(do_rand_init) |
| { |
| int ret = 1; |
| |
| #ifndef OPENSSL_NO_ENGINE |
| rand_engine_lock = CRYPTO_THREAD_glock_new("rand_engine"); |
| ret &= rand_engine_lock != NULL; |
| #endif |
| rand_meth_lock = CRYPTO_THREAD_glock_new("rand_meth"); |
| ret &= rand_meth_lock != NULL; |
| |
| rand_bytes.lock = CRYPTO_THREAD_glock_new("rand_bytes"); |
| ret &= rand_bytes.lock != NULL; |
| rand_bytes.curr = 0; |
| rand_bytes.size = MAX_RANDOMNESS_HELD; |
| rand_bytes.secure = CRYPTO_secure_malloc_initialized(); |
| rand_bytes.buff = rand_bytes.secure |
| ? OPENSSL_secure_malloc(rand_bytes.size) |
| : OPENSSL_malloc(rand_bytes.size); |
| ret &= rand_bytes.buff != NULL; |
| return ret; |
| } |
| |
| void rand_cleanup_int(void) |
| { |
| const RAND_METHOD *meth = default_RAND_meth; |
| |
| if (meth != NULL && meth->cleanup != NULL) |
| meth->cleanup(); |
| RAND_set_rand_method(NULL); |
| #ifndef OPENSSL_NO_ENGINE |
| CRYPTO_THREAD_lock_free(rand_engine_lock); |
| #endif |
| CRYPTO_THREAD_lock_free(rand_meth_lock); |
| CRYPTO_THREAD_lock_free(rand_bytes.lock); |
| if (rand_bytes.secure) |
| OPENSSL_secure_clear_free(rand_bytes.buff, rand_bytes.size); |
| else |
| OPENSSL_clear_free(rand_bytes.buff, rand_bytes.size); |
| } |
| |
| /* |
| * RAND_poll_ex() gets a function pointer to call when it has random bytes. |
| * RAND_poll() sets the function pointer to be a wrapper that calls RAND_add(). |
| */ |
| static void call_rand_add(void* arg, const void *buf, int num, double r) |
| { |
| RAND_add(buf, num, r); |
| } |
| |
| int RAND_poll(void) |
| { |
| return RAND_poll_ex(call_rand_add, NULL); |
| } |
| |
| 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->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->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 != RAND_OpenSSL()) |
| return RAND_bytes(buf, num); |
| |
| drbg = RAND_DRBG_get0_priv_global(); |
| if (drbg == NULL) |
| return 0; |
| |
| return RAND_DRBG_generate(drbg, buf, num, 0, NULL, 0); |
| } |
| |
| int RAND_bytes(unsigned char *buf, int num) |
| { |
| const RAND_METHOD *meth = RAND_get_rand_method(); |
| |
| if (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->pseudorand != NULL) |
| return meth->pseudorand(buf, num); |
| return -1; |
| } |
| #endif |
| |
| int RAND_status(void) |
| { |
| const RAND_METHOD *meth = RAND_get_rand_method(); |
| |
| if (meth->status != NULL) |
| return meth->status(); |
| return 0; |
| } |