X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Frand_lib.c;h=defa3ecb538cfaf3b8039c39d1cf7727ea9c4396;hp=55c90cc4bfa4b2e4023681d5a1f55b6e6f957c4e;hb=7caf122e717e79afcb986fe217e77a630b67bf4c;hpb=b0700d2c8de79252ba605748a075cf2e5d670da1 diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c index 55c90cc4bf..defa3ecb53 100644 --- a/crypto/rand/rand_lib.c +++ b/crypto/rand/rand_lib.c @@ -1,267 +1,861 @@ -/* crypto/rand/rand_lib.c */ -/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) - * All rights reserved. - * - * This package is an SSL implementation written - * by Eric Young (eay@cryptsoft.com). - * The implementation was written so as to conform with Netscapes SSL. - * - * This library is free for commercial and non-commercial use as long as - * the following conditions are aheared to. The following conditions - * apply to all code found in this distribution, be it the RC4, RSA, - * lhash, DES, etc., code; not just the SSL code. The SSL documentation - * included with this distribution is covered by the same copyright terms - * except that the holder is Tim Hudson (tjh@cryptsoft.com). - * - * Copyright remains Eric Young's, and as such any Copyright notices in - * the code are not to be removed. - * If this package is used in a product, Eric Young should be given attribution - * as the author of the parts of the library used. - * This can be in the form of a textual message at program startup or - * in documentation (online or textual) provided with the package. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * "This product includes cryptographic software written by - * Eric Young (eay@cryptsoft.com)" - * The word 'cryptographic' can be left out if the rouines from the library - * being used are not cryptographic related :-). - * 4. If you include any Windows specific code (or a derivative thereof) from - * the apps directory (application code) you must include an acknowledgement: - * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" - * - * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. +/* + * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved. * - * The licence and distribution terms for any publically available version or - * derivative of this code cannot be changed. i.e. this code cannot simply be - * copied and put under another distribution licence - * [including the GNU Public Licence.] + * 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 #include #include "internal/cryptlib.h" -#include - -#ifndef OPENSSL_NO_ENGINE -# include +#include +#include "internal/rand_int.h" +#include +#include "internal/thread_once.h" +#include "rand_lcl.h" +#ifdef OPENSSL_SYS_UNIX +# include +# include +# include #endif +#include "e_os.h" + +/* Macro to convert two thirty two bit values into a sixty four bit one */ +#define TWO32TO64(a, b) ((((uint64_t)(a)) << 32) + (b)) -#ifdef OPENSSL_FIPS -# include -# include +/* + * Check for the existence and support of POSIX timers. The standard + * says that the _POSIX_TIMERS macro will have a positive value if they + * are available. + * + * However, we want an additional constraint: that the timer support does + * not require an extra library dependency. Early versions of glibc + * require -lrt to be specified on the link line to access the timers, + * so this needs to be checked for. + * + * It is worse because some libraries define __GLIBC__ but don't + * support the version testing macro (e.g. uClibc). This means + * an extra check is needed. + * + * The final condition is: + * "have posix timers and either not glibc or glibc without -lrt" + * + * The nested #if sequences are required to avoid using a parameterised + * macro that might be undefined. + */ +#undef OSSL_POSIX_TIMER_OKAY +#if defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0 +# if defined(__GLIBC__) +# if defined(__GLIBC_PREREQ) +# if __GLIBC_PREREQ(2, 17) +# define OSSL_POSIX_TIMER_OKAY +# endif +# endif +# else +# define OSSL_POSIX_TIMER_OKAY +# endif #endif #ifndef OPENSSL_NO_ENGINE /* non-NULL if default_RAND_meth is ENGINE-provided */ -static ENGINE *funct_ref = NULL; +static ENGINE *funct_ref; +static CRYPTO_RWLOCK *rand_engine_lock; #endif -static const RAND_METHOD *default_RAND_meth = NULL; +static CRYPTO_RWLOCK *rand_meth_lock; +static const RAND_METHOD *default_RAND_meth; +static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT; -int RAND_set_rand_method(const RAND_METHOD *meth) +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!" + +/* + * 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) { -#ifndef OPENSSL_NO_ENGINE - if (funct_ref) { - ENGINE_finish(funct_ref); - funct_ref = NULL; + 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); + } } -#endif - default_RAND_meth = meth; - return 1; + return rand_pool_entropy_available(pool); } +#endif -const RAND_METHOD *RAND_get_rand_method(void) +#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) { - if (!default_RAND_meth) { -#ifndef OPENSSL_NO_ENGINE - ENGINE *e = ENGINE_get_default_RAND(); - if (e) { - default_RAND_meth = ENGINE_get_RAND(e); - if (!default_RAND_meth) { - ENGINE_finish(e); - e = NULL; + size_t bytes_needed; + unsigned char *buffer; + + bytes_needed = rand_pool_bytes_needed(pool, 8 /*entropy_per_byte*/); + if (bytes_needed > 0) { + buffer = rand_pool_add_begin(pool, bytes_needed); + + if (buffer != NULL) { + + /* If RDSEED is available, use that. */ + if ((OPENSSL_ia32cap_P[2] & (1 << 18)) != 0) { + if (OPENSSL_ia32_rdseed_bytes(buffer, bytes_needed) + == bytes_needed) + return rand_pool_add_end(pool, + bytes_needed, + 8 * bytes_needed); + } + + /* Second choice is RDRAND. */ + if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) { + if (OPENSSL_ia32_rdrand_bytes(buffer, bytes_needed) + == bytes_needed) + return rand_pool_add_end(pool, + bytes_needed, + 8 * bytes_needed); } + + return rand_pool_add_end(pool, 0, 0); } - if (e) - funct_ref = e; - else -#endif - default_RAND_meth = RAND_OpenSSL(); } - return default_RAND_meth; + + return rand_pool_entropy_available(pool); } +#endif -#ifndef OPENSSL_NO_ENGINE -int RAND_set_rand_engine(ENGINE *engine) + +/* + * 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) { - const RAND_METHOD *tmp_meth = NULL; - if (engine) { - if (!ENGINE_init(engine)) - return 0; - tmp_meth = ENGINE_get_RAND(engine); - if (!tmp_meth) { - ENGINE_finish(engine); + size_t ret = 0; + size_t entropy_available = 0; + RAND_POOL *pool; + + if (drbg->parent && 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; + } + + pool = rand_pool_new(entropy, min_len, max_len); + if (pool == NULL) + return 0; + + if (drbg->pool) { + rand_pool_add(pool, + rand_pool_buffer(drbg->pool), + rand_pool_length(drbg->pool), + rand_pool_entropy(drbg->pool)); + rand_pool_free(drbg->pool); + drbg->pool = NULL; + } + + if (drbg->parent) { + size_t bytes_needed = rand_pool_bytes_needed(pool, 8); + unsigned char *buffer = rand_pool_add_begin(pool, bytes_needed); + + if (buffer != NULL) { + size_t bytes = 0; + + /* + * Get random from parent, include our state as additional input. + * 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); + + entropy_available = rand_pool_add_end(pool, bytes, 8 * bytes); + } + + } 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); return 0; } + + /* Get entropy by polling system entropy sources. */ + entropy_available = rand_pool_acquire_entropy(pool); } - /* This function releases any prior ENGINE so call it first */ - RAND_set_rand_method(tmp_meth); - funct_ref = engine; - return 1; + + if (entropy_available > 0) { + ret = rand_pool_length(pool); + *pout = rand_pool_detach(pool); + } + + rand_pool_free(pool); + return ret; } + +/* + * Find a suitable source of time. Start with the highest resolution source + * and work down to the slower ones. This is added as additional data and + * isn't counted as randomness, so any result is acceptable. + * + * Returns 0 when we weren't able to find any time source + */ +static uint64_t get_timer_bits(void) +{ + uint64_t res = OPENSSL_rdtsc(); + + if (res != 0) + return res; +#if defined(_WIN32) + { + LARGE_INTEGER t; + FILETIME ft; + + if (QueryPerformanceCounter(&t) != 0) + return t.QuadPart; + GetSystemTimeAsFileTime(&ft); + return TWO32TO64(ft.dwHighDateTime, ft.dwLowDateTime); + } +#elif defined(__sun) || defined(__hpux) + return gethrtime(); +#elif defined(_AIX) + { + timebasestruct_t t; + + read_wall_time(&t, TIMEBASE_SZ); + return TWO32TO64(t.tb_high, t.tb_low); + } +#else + +# if defined(OSSL_POSIX_TIMER_OKAY) + { + struct timespec ts; + clockid_t cid; + +# ifdef CLOCK_BOOTTIME + cid = CLOCK_BOOTTIME; +# elif defined(_POSIX_MONOTONIC_CLOCK) + cid = CLOCK_MONOTONIC; +# else + cid = CLOCK_REALTIME; +# endif + + if (clock_gettime(cid, &ts) == 0) + return TWO32TO64(ts.tv_sec, ts.tv_nsec); + } +# endif +# if defined(__unix__) \ + || (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L) + { + struct timeval tv; + + if (gettimeofday(&tv, NULL) == 0) + return TWO32TO64(tv.tv_sec, tv.tv_usec); + } +# endif + { + time_t t = time(NULL); + if (t == (time_t)-1) + return 0; + return t; + } #endif +} -void RAND_cleanup(void) +/* + * 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(unsigned char **pout, size_t max_len) { - const RAND_METHOD *meth = RAND_get_rand_method(); - if (meth && meth->cleanup) + RAND_POOL *pool; + CRYPTO_THREAD_ID thread_id; + size_t len; +#ifdef OPENSSL_SYS_UNIX + pid_t pid; +#elif defined(OPENSSL_SYS_WIN32) + DWORD pid; +#endif + uint64_t tbits; + + pool = rand_pool_new(0, 0, max_len); + if (pool == NULL) + return 0; + +#ifdef OPENSSL_SYS_UNIX + pid = getpid(); + rand_pool_add(pool, (unsigned char *)&pid, sizeof(pid), 0); +#elif defined(OPENSSL_SYS_WIN32) + pid = GetCurrentProcessId(); + rand_pool_add(pool, (unsigned char *)&pid, sizeof(pid), 0); +#endif + + thread_id = CRYPTO_THREAD_get_current_id(); + if (thread_id != 0) + rand_pool_add(pool, (unsigned char *)&thread_id, sizeof(thread_id), 0); + + tbits = get_timer_bits(); + if (tbits != 0) + rand_pool_add(pool, (unsigned char *)&tbits, sizeof(tbits), 0); + + /* TODO: Use RDSEED? */ + + len = rand_pool_length(pool); + if (len != 0) + *pout = rand_pool_detach(pool); + rand_pool_free(pool); + + return len; +} + +/* + * Implements the cleanup_entropy() callback (see RAND_DRBG_set_callbacks()) + * + */ +void rand_drbg_cleanup_entropy(RAND_DRBG *drbg, + unsigned char *out, size_t outlen) +{ + OPENSSL_secure_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_lock_new(); + ret &= rand_engine_lock != NULL; +#endif + rand_meth_lock = CRYPTO_THREAD_lock_new(); + ret &= rand_meth_lock != 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); } -void RAND_seed(const void *buf, int num) +/* + * 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 && meth->seed) - meth->seed(buf, num); + + 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, + RAND_DRBG_STRENGTH / 8, + DRBG_MINMAX_FACTOR * (RAND_DRBG_STRENGTH / 8)); + 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; } -void RAND_add(const void *buf, int num, double entropy) +/* + * The 'random pool' acts as a dumb container for collecting random + * input from various entropy sources. The pool has no knowledge about + * whether its randomness is fed into a legacy RAND_METHOD via RAND_add() + * or into a new style RAND_DRBG. It is the callers duty to 1) initialize the + * random pool, 2) pass it to the polling callbacks, 3) seed the RNG, and + * 4) cleanup the random pool again. + * + * The random pool contains no locking mechanism because its scope and + * lifetime is intended to be restricted to a single stack frame. + */ +struct rand_pool_st { + unsigned char *buffer; /* points to the beginning of the random pool */ + size_t len; /* current number of random bytes contained in the pool */ + + size_t min_len; /* minimum number of random bytes requested */ + size_t max_len; /* maximum number of random bytes (allocated buffer size) */ + size_t entropy; /* current entropy count in bits */ + size_t requested_entropy; /* requested entropy count in bits */ +}; + +/* + * Allocate memory and initialize a new random pool + */ + +RAND_POOL *rand_pool_new(int entropy, size_t min_len, size_t max_len) { - const RAND_METHOD *meth = RAND_get_rand_method(); - if (meth && meth->add) - meth->add(buf, num, entropy); + RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool)); + + if (pool == NULL) { + RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE); + goto err; + } + + pool->min_len = min_len; + pool->max_len = max_len; + + pool->buffer = OPENSSL_secure_zalloc(pool->max_len); + if (pool->buffer == NULL) { + RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE); + goto err; + } + + pool->requested_entropy = entropy; + + return pool; + +err: + OPENSSL_free(pool); + return NULL; } -int RAND_bytes(unsigned char *buf, int num) +/* + * Free |pool|, securely erasing its buffer. + */ +void rand_pool_free(RAND_POOL *pool) { - const RAND_METHOD *meth = RAND_get_rand_method(); - if (meth && meth->bytes) - return meth->bytes(buf, num); - return (-1); + if (pool == NULL) + return; + + OPENSSL_secure_clear_free(pool->buffer, pool->max_len); + OPENSSL_free(pool); } -#ifndef OPENSSL_NO_DEPRECATED -int RAND_pseudo_bytes(unsigned char *buf, int num) +/* + * Return the |pool|'s buffer to the caller (readonly). + */ +const unsigned char *rand_pool_buffer(RAND_POOL *pool) { - const RAND_METHOD *meth = RAND_get_rand_method(); - if (meth && meth->pseudorand) - return meth->pseudorand(buf, num); - return (-1); + return pool->buffer; } -#endif -int RAND_status(void) +/* + * Return the |pool|'s entropy to the caller. + */ +size_t rand_pool_entropy(RAND_POOL *pool) { - const RAND_METHOD *meth = RAND_get_rand_method(); - if (meth && meth->status) - return meth->status(); - return 0; + 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(). + */ +unsigned char *rand_pool_detach(RAND_POOL *pool) +{ + unsigned char *ret = pool->buffer; + pool->buffer = NULL; + return ret; } -#ifdef OPENSSL_FIPS /* - * FIPS DRBG initialisation code. This sets up the DRBG for use by the rest - * of OpenSSL. + * If every byte of the input contains |entropy_per_bytes| bits of entropy, + * how many bytes does one need to obtain at least |bits| bits of entropy? + */ +#define ENTROPY_TO_BYTES(bits, entropy_per_bytes) \ + (((bits) + ((entropy_per_bytes) - 1))/(entropy_per_bytes)) + + +/* + * 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->requested_entropy) + return 0; + + if (pool->len < pool->min_len) + return 0; + + return pool->entropy; +} /* - * Entropy gatherer: use standard OpenSSL PRNG to seed (this will gather - * entropy internally through RAND_poll(). + * Returns the (remaining) amount of entropy needed to fill + * the random pool. */ -static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout, - int entropy, size_t min_len, size_t max_len) +size_t rand_pool_entropy_needed(RAND_POOL *pool) { - /* Round up request to multiple of block size */ - min_len = ((min_len + 19) / 20) * 20; - *pout = OPENSSL_malloc(min_len); - if (!*pout) + if (pool->entropy < pool->requested_entropy) + return pool->requested_entropy - pool->entropy; + + return 0; +} + +/* + * Returns the number of bytes needed to fill the pool, assuming + * the input has 'entropy_per_byte' entropy bits per byte. + * In case of an error, 0 is returned. + */ + +size_t rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_per_byte) +{ + size_t bytes_needed; + size_t entropy_needed = rand_pool_entropy_needed(pool); + + if (entropy_per_byte < 1 || entropy_per_byte > 8) { + RANDerr(RAND_F_RAND_POOL_BYTES_NEEDED, RAND_R_ARGUMENT_OUT_OF_RANGE); return 0; - if (RAND_OpenSSL()->bytes(*pout, min_len) <= 0) { - OPENSSL_free(*pout); - *pout = NULL; + } + + bytes_needed = ENTROPY_TO_BYTES(entropy_needed, entropy_per_byte); + + 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; } - return min_len; + + 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; + + return bytes_needed; } -static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen) +/* Returns the remaining number of bytes available */ +size_t rand_pool_bytes_remaining(RAND_POOL *pool) { - OPENSSL_clear_free(out, olen); + return pool->max_len - pool->len; } /* - * Set "additional input" when generating random data. This uses the current - * PID, a time value and a counter. + * 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. + * + * Return available amount of entropy after this operation. + * (see rand_pool_entropy_available(pool)) */ +size_t 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 (len > 0) { + memcpy(pool->buffer + pool->len, buffer, len); + pool->len += len; + pool->entropy += entropy; + } + + return rand_pool_entropy_available(pool); +} -static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout) +/* + * 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 udpate operation (see next comment). + */ +unsigned char *rand_pool_add_begin(RAND_POOL *pool, size_t len) { - /* Use of static variables is OK as this happens under a lock */ - static unsigned char buf[16]; - static unsigned long counter; - FIPS_get_timevec(buf, &counter); - rand_hw_xor(buf, sizeof(buf)); - *pout = buf; - return sizeof(buf); + 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; + } + + return pool->buffer + pool->len; } /* - * RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is - * correctly seeded by RAND_poll(). + * 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. */ +size_t rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy) +{ + if (len > pool->max_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 rand_pool_entropy_available(pool); +} -static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen, - double entropy) +int RAND_set_rand_method(const RAND_METHOD *meth) { - return RAND_OpenSSL()->add(in, inlen, entropy); + 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; } -static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen) +const RAND_METHOD *RAND_get_rand_method(void) { - return RAND_OpenSSL()->seed(in, inlen); + 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; } -int RAND_init_fips(void) +#ifndef OPENSSL_NO_ENGINE +int RAND_set_rand_engine(ENGINE *engine) { - DRBG_CTX *dctx; - size_t plen; - unsigned char pers[32], *p; - dctx = FIPS_get_default_drbg(); - FIPS_drbg_init(dctx, NID_aes_256_ctr, DRBG_FLAG_CTR_USE_DF); - FIPS_drbg_set_callbacks(dctx, - drbg_get_entropy, drbg_free_entropy, 20, - drbg_get_entropy, drbg_free_entropy); - FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0, - drbg_rand_seed, drbg_rand_add); - /* Personalisation string: a string followed by date time vector */ - strcpy((char *)pers, "OpenSSL DRBG2.0"); - plen = drbg_get_adin(dctx, &p); - memcpy(pers + 16, p, plen); + const RAND_METHOD *tmp_meth = NULL; - FIPS_drbg_instantiate(dctx, pers, sizeof(pers)); - FIPS_rand_set_method(FIPS_drbg_method()); + 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; + int ret; + + if (meth != RAND_OpenSSL()) + return RAND_bytes(buf, num); + + drbg = RAND_DRBG_get0_private(); + if (drbg == NULL) + return 0; + + ret = RAND_DRBG_bytes(drbg, buf, num); + return ret; +} + +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; +}