X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Fmd_rand.c;h=4b874e3bedf4a9459e1ee8487769076983938e02;hp=ce901759db14bd376ce604cc9a2ac74e67b6138b;hb=1150999e04ab826a9e8607e87db7fdd72f688ec4;hpb=1a33f6da8b86c249ba5438bc7e7f840257fac275 diff --git a/crypto/rand/md_rand.c b/crypto/rand/md_rand.c index ce901759db..4b874e3bed 100644 --- a/crypto/rand/md_rand.c +++ b/crypto/rand/md_rand.c @@ -1,582 +1,654 @@ -/* crypto/rand/md_rand.c */ -/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) - * All rights reserved. +/* + * Copyright 1995-2016 The OpenSSL Project Authors. 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. - * - * 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 */ -#define ENTROPY_NEEDED 16 /* require 128 bits = 16 bytes of randomness */ - -#ifndef MD_RAND_DEBUG -# ifndef NDEBUG -# define NDEBUG -# endif -#endif - -#include #include -#include #include -#include "openssl/e_os.h" +#include "e_os.h" +#if !(defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_DSPBIOS)) +# include +#endif +#if defined(OPENSSL_SYS_VXWORKS) +# include +#endif + +#include #include +#include +#include +#include "rand_lcl.h" + #include -#if !defined(USE_MD5_RAND) && !defined(USE_SHA1_RAND) && !defined(USE_MDC2_RAND) && !defined(USE_MD2_RAND) -#if !defined(NO_SHA) && !defined(NO_SHA1) -#define USE_SHA1_RAND -#elif !defined(NO_MD5) -#define USE_MD5_RAND -#elif !defined(NO_MDC2) && !defined(NO_DES) -#define USE_MDC2_RAND -#elif !defined(NO_MD2) -#define USE_MD2_RAND -#else -#error No message digest algorithm available +#ifdef OPENSSL_FIPS +# include #endif + +#ifdef BN_DEBUG +# define PREDICT #endif -/* Changed how the state buffer used. I now attempt to 'wrap' such - * that I don't run over the same locations the next time go through - * the 1023 bytes - many thanks to - * Robert J. LeBlanc for his comments - */ +/* #define PREDICT 1 */ -#if defined(USE_MD5_RAND) -#include -#define MD_DIGEST_LENGTH MD5_DIGEST_LENGTH -#define MD_CTX MD5_CTX -#define MD_Init(a) MD5_Init(a) -#define MD_Update(a,b,c) MD5_Update(a,b,c) -#define MD_Final(a,b) MD5_Final(a,b) -#define MD(a,b,c) MD5(a,b,c) -#elif defined(USE_SHA1_RAND) -#include -#define MD_DIGEST_LENGTH SHA_DIGEST_LENGTH -#define MD_CTX SHA_CTX -#define MD_Init(a) SHA1_Init(a) -#define MD_Update(a,b,c) SHA1_Update(a,b,c) -#define MD_Final(a,b) SHA1_Final(a,b) -#define MD(a,b,c) SHA1(a,b,c) -#elif defined(USE_MDC2_RAND) -#include -#define MD_DIGEST_LENGTH MDC2_DIGEST_LENGTH -#define MD_CTX MDC2_CTX -#define MD_Init(a) MDC2_Init(a) -#define MD_Update(a,b,c) MDC2_Update(a,b,c) -#define MD_Final(a,b) MDC2_Final(a,b) -#define MD(a,b,c) MDC2(a,b,c) -#elif defined(USE_MD2_RAND) -#include -#define MD_DIGEST_LENGTH MD2_DIGEST_LENGTH -#define MD_CTX MD2_CTX -#define MD_Init(a) MD2_Init(a) -#define MD_Update(a,b,c) MD2_Update(a,b,c) -#define MD_Final(a,b) MD2_Final(a,b) -#define MD(a,b,c) MD2(a,b,c) -#endif +#define STATE_SIZE 1023 +static int state_num = 0, state_index = 0; +static unsigned char state[STATE_SIZE + MD_DIGEST_LENGTH]; +static unsigned char md[MD_DIGEST_LENGTH]; +static long md_count[2] = { 0, 0 }; -#include +static double entropy = 0; +static int initialized = 0; -/* #define NORAND 1 */ -/* #define PREDICT 1 */ +static CRYPTO_RWLOCK *rand_lock = NULL; +static CRYPTO_RWLOCK *rand_tmp_lock = NULL; +static CRYPTO_ONCE rand_lock_init = CRYPTO_ONCE_STATIC_INIT; -#define STATE_SIZE 1023 -static int state_num=0,state_index=0; -static unsigned char state[STATE_SIZE+MD_DIGEST_LENGTH]; -static unsigned char md[MD_DIGEST_LENGTH]; -static long md_count[2]={0,0}; -static double entropy=0; -static int initialized=0; - -const char *RAND_version="RAND" OPENSSL_VERSION_PTEXT; - -static void ssleay_rand_cleanup(void); -static void ssleay_rand_seed(const void *buf, int num); -static void ssleay_rand_add(const void *buf, int num, double add_entropy); -static int ssleay_rand_bytes(unsigned char *buf, int num); -static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num); - -RAND_METHOD rand_ssleay_meth={ - ssleay_rand_seed, - ssleay_rand_bytes, - ssleay_rand_cleanup, - ssleay_rand_add, - ssleay_rand_pseudo_bytes, - }; - -RAND_METHOD *RAND_SSLeay(void) - { - return(&rand_ssleay_meth); - } - -static void ssleay_rand_cleanup(void) - { - memset(state,0,sizeof(state)); - state_num=0; - state_index=0; - memset(md,0,MD_DIGEST_LENGTH); - md_count[0]=0; - md_count[1]=0; - entropy=0; - } - -static void ssleay_rand_add(const void *buf, int num, double add) - { - int i,j,k,st_idx; - long md_c[2]; - unsigned char local_md[MD_DIGEST_LENGTH]; - MD_CTX m; - -#ifdef NORAND - return; -#endif +/* May be set only when a thread holds rand_lock (to prevent double locking) */ +static unsigned int crypto_lock_rand = 0; +/* access to locking_threadid is synchronized by rand_tmp_lock */ +/* valid iff crypto_lock_rand is set */ +static CRYPTO_THREAD_ID locking_threadid; - /* - * (Based on the rand(3) manpage) - * - * The input is chopped up into units of 20 bytes (or less for - * the last block). Each of these blocks is run through the hash - * function as follows: The data passed to the hash function - * is the current 'md', the same number of bytes from the 'state' - * (the location determined by in incremented looping index) as - * the current 'block', the new key data 'block', and 'count' - * (which is incremented after each use). - * The result of this is kept in 'md' and also xored into the - * 'state' at the same locations that were used as input into the - * hash function. - */ - - CRYPTO_w_lock(CRYPTO_LOCK_RAND); - st_idx=state_index; - - /* use our own copies of the counters so that even - * if a concurrent thread seeds with exactly the - * same data and uses the same subarray there's _some_ - * difference */ - md_c[0] = md_count[0]; - md_c[1] = md_count[1]; - - memcpy(local_md, md, sizeof md); - - /* state_index <= state_num <= STATE_SIZE */ - state_index += num; - if (state_index >= STATE_SIZE) - { - state_index%=STATE_SIZE; - state_num=STATE_SIZE; - } - else if (state_num < STATE_SIZE) - { - if (state_index > state_num) - state_num=state_index; - } - /* state_index <= state_num <= STATE_SIZE */ - - /* state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE] - * are what we will use now, but other threads may use them - * as well */ - - md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0); - - CRYPTO_w_unlock(CRYPTO_LOCK_RAND); - - for (i=0; i MD_DIGEST_LENGTH)?MD_DIGEST_LENGTH:j; - - MD_Init(&m); - MD_Update(&m,local_md,MD_DIGEST_LENGTH); - k=(st_idx+j)-STATE_SIZE; - if (k > 0) - { - MD_Update(&m,&(state[st_idx]),j-k); - MD_Update(&m,&(state[0]),k); - } - else - MD_Update(&m,&(state[st_idx]),j); - - MD_Update(&m,buf,j); - MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)); - MD_Final(local_md,&m); - md_c[1]++; - - buf=(const char *)buf + j; - - for (k=0; k= STATE_SIZE) - st_idx=0; - } - } - memset((char *)&m,0,sizeof(m)); - - CRYPTO_w_lock(CRYPTO_LOCK_RAND); - /* Don't just copy back local_md into md -- this could mean that - * other thread's seeding remains without effect (except for - * the incremented counter). By XORing it we keep at least as - * much entropy as fits into md. */ - for (k = 0; k < sizeof md; k++) - { - md[k] ^= local_md[k]; - } - CRYPTO_w_unlock(CRYPTO_LOCK_RAND); - -#ifndef THREADS - assert(md_c[1] == md_count[1]); +#ifdef PREDICT +int rand_predictable = 0; #endif - if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */ - entropy += add; - } - -static void ssleay_rand_seed(const void *buf, int num) - { - ssleay_rand_add(buf, num, num); - } - -static void ssleay_rand_initialize(void) - { - unsigned long l; -#ifndef GETPID_IS_MEANINGLESS - pid_t curr_pid = getpid(); + +static void rand_hw_seed(EVP_MD_CTX *ctx); + +static void rand_cleanup(void); +static int rand_seed(const void *buf, int num); +static int rand_add(const void *buf, int num, double add_entropy); +static int rand_bytes(unsigned char *buf, int num, int pseudo); +static int rand_nopseudo_bytes(unsigned char *buf, int num); +#if OPENSSL_API_COMPAT < 0x10100000L +static int rand_pseudo_bytes(unsigned char *buf, int num); #endif -#ifdef DEVRANDOM - FILE *fh; +static int rand_status(void); + +static RAND_METHOD rand_meth = { + rand_seed, + rand_nopseudo_bytes, + rand_cleanup, + rand_add, +#if OPENSSL_API_COMPAT < 0x10100000L + rand_pseudo_bytes, +#else + NULL, #endif + rand_status +}; + +static void do_rand_lock_init(void) +{ + rand_lock = CRYPTO_THREAD_lock_new(); + rand_tmp_lock = CRYPTO_THREAD_lock_new(); +} + +RAND_METHOD *RAND_OpenSSL(void) +{ + return (&rand_meth); +} + +static void rand_cleanup(void) +{ + OPENSSL_cleanse(state, sizeof(state)); + state_num = 0; + state_index = 0; + OPENSSL_cleanse(md, MD_DIGEST_LENGTH); + md_count[0] = 0; + md_count[1] = 0; + entropy = 0; + initialized = 0; + CRYPTO_THREAD_lock_free(rand_lock); + CRYPTO_THREAD_lock_free(rand_tmp_lock); +} + +static int rand_add(const void *buf, int num, double add) +{ + int i, j, k, st_idx; + long md_c[2]; + unsigned char local_md[MD_DIGEST_LENGTH]; + EVP_MD_CTX *m; + int do_not_lock; + int rv = 0; + + if (!num) + return 1; + + /* + * (Based on the rand(3) manpage) + * + * The input is chopped up into units of 20 bytes (or less for + * the last block). Each of these blocks is run through the hash + * function as follows: The data passed to the hash function + * is the current 'md', the same number of bytes from the 'state' + * (the location determined by in incremented looping index) as + * the current 'block', the new key data 'block', and 'count' + * (which is incremented after each use). + * The result of this is kept in 'md' and also xored into the + * 'state' at the same locations that were used as input into the + * hash function. + */ + + m = EVP_MD_CTX_new(); + if (m == NULL) + goto err; + + CRYPTO_THREAD_run_once(&rand_lock_init, do_rand_lock_init); + + /* check if we already have the lock */ + if (crypto_lock_rand) { + CRYPTO_THREAD_ID cur = CRYPTO_THREAD_get_current_id(); + CRYPTO_THREAD_read_lock(rand_tmp_lock); + do_not_lock = CRYPTO_THREAD_compare_id(locking_threadid, cur); + CRYPTO_THREAD_unlock(rand_tmp_lock); + } else + do_not_lock = 0; + + if (!do_not_lock) + CRYPTO_THREAD_write_lock(rand_lock); + st_idx = state_index; + + /* + * use our own copies of the counters so that even if a concurrent thread + * seeds with exactly the same data and uses the same subarray there's + * _some_ difference + */ + md_c[0] = md_count[0]; + md_c[1] = md_count[1]; + + memcpy(local_md, md, sizeof md); + + /* state_index <= state_num <= STATE_SIZE */ + state_index += num; + if (state_index >= STATE_SIZE) { + state_index %= STATE_SIZE; + state_num = STATE_SIZE; + } else if (state_num < STATE_SIZE) { + if (state_index > state_num) + state_num = state_index; + } + /* state_index <= state_num <= STATE_SIZE */ + + /* + * state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE] are what we + * will use now, but other threads may use them as well + */ + + md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0); + + if (!do_not_lock) + CRYPTO_THREAD_unlock(rand_lock); + + for (i = 0; i < num; i += MD_DIGEST_LENGTH) { + j = (num - i); + j = (j > MD_DIGEST_LENGTH) ? MD_DIGEST_LENGTH : j; + + if (!MD_Init(m)) + goto err; + if (!MD_Update(m, local_md, MD_DIGEST_LENGTH)) + goto err; + k = (st_idx + j) - STATE_SIZE; + if (k > 0) { + if (!MD_Update(m, &(state[st_idx]), j - k)) + goto err; + if (!MD_Update(m, &(state[0]), k)) + goto err; + } else if (!MD_Update(m, &(state[st_idx]), j)) + goto err; + + /* DO NOT REMOVE THE FOLLOWING CALL TO MD_Update()! */ + if (!MD_Update(m, buf, j)) + goto err; + /* + * We know that line may cause programs such as purify and valgrind + * to complain about use of uninitialized data. The problem is not, + * it's with the caller. Removing that line will make sure you get + * really bad randomness and thereby other problems such as very + * insecure keys. + */ + + if (!MD_Update(m, (unsigned char *)&(md_c[0]), sizeof(md_c))) + goto err; + if (!MD_Final(m, local_md)) + goto err; + md_c[1]++; + + buf = (const char *)buf + j; + + for (k = 0; k < j; k++) { + /* + * Parallel threads may interfere with this, but always each byte + * of the new state is the XOR of some previous value of its and + * local_md (intermediate values may be lost). Alway using locking + * could hurt performance more than necessary given that + * conflicts occur only when the total seeding is longer than the + * random state. + */ + state[st_idx++] ^= local_md[k]; + if (st_idx >= STATE_SIZE) + st_idx = 0; + } + } + + if (!do_not_lock) + CRYPTO_THREAD_write_lock(rand_lock); + /* + * Don't just copy back local_md into md -- this could mean that other + * thread's seeding remains without effect (except for the incremented + * counter). By XORing it we keep at least as much entropy as fits into + * md. + */ + for (k = 0; k < (int)sizeof(md); k++) { + md[k] ^= local_md[k]; + } + if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */ + entropy += add; + if (!do_not_lock) + CRYPTO_THREAD_unlock(rand_lock); + + rv = 1; + err: + EVP_MD_CTX_free(m); + return rv; +} + +static int rand_seed(const void *buf, int num) +{ + return rand_add(buf, num, (double)num); +} - CRYPTO_w_unlock(CRYPTO_LOCK_RAND); - /* put in some default random data, we need more than just this */ +static int rand_bytes(unsigned char *buf, int num, int pseudo) +{ + static volatile int stirred_pool = 0; + int i, j, k, st_num, st_idx; + int num_ceil; + int ok; + long md_c[2]; + unsigned char local_md[MD_DIGEST_LENGTH]; + EVP_MD_CTX *m; #ifndef GETPID_IS_MEANINGLESS - l=curr_pid; - RAND_add(&l,sizeof(l),0); - l=getuid(); - RAND_add(&l,sizeof(l),0); -#endif - l=time(NULL); - RAND_add(&l,sizeof(l),0); - -#ifdef DEVRANDOM - /* Use a random entropy pool device. Linux and FreeBSD have - * this. Use /dev/urandom if you can as /dev/random will block - * if it runs out of random entries. */ - - if ((fh = fopen(DEVRANDOM, "r")) != NULL) - { - unsigned char tmpbuf[ENTROPY_NEEDED]; - int n; - - setvbuf(fh, NULL, _IONBF, 0); - n=fread((unsigned char *)tmpbuf,1,ENTROPY_NEEDED,fh); - fclose(fh); - RAND_add(tmpbuf,sizeof tmpbuf,n); - memset(tmpbuf,0,n); - } -#endif -#ifdef PURIFY - memset(state,0,STATE_SIZE); - memset(md,0,MD_DIGEST_LENGTH); + pid_t curr_pid = getpid(); #endif - CRYPTO_w_lock(CRYPTO_LOCK_RAND); - initialized=1; - } - -static int ssleay_rand_bytes(unsigned char *buf, int num) - { - int i,j,k,st_num,st_idx; - int ok; - long md_c[2]; - unsigned char local_md[MD_DIGEST_LENGTH]; - MD_CTX m; -#ifndef GETPID_IS_MEANINGLESS - pid_t curr_pid = getpid(); + time_t curr_time = time(NULL); + int do_stir_pool = 0; +/* time value for various platforms */ +#ifdef OPENSSL_SYS_WIN32 + FILETIME tv; +# ifdef _WIN32_WCE + SYSTEMTIME t; + GetSystemTime(&t); + SystemTimeToFileTime(&t, &tv); +# else + GetSystemTimeAsFileTime(&tv); +# endif +#elif defined(OPENSSL_SYS_VXWORKS) + struct timespec tv; + clock_gettime(CLOCK_REALTIME, &ts); +#elif defined(OPENSSL_SYS_DSPBIOS) + unsigned long long tv, OPENSSL_rdtsc(); + tv = OPENSSL_rdtsc(); +#else + struct timeval tv; + gettimeofday(&tv, NULL); #endif #ifdef PREDICT - { - static unsigned char val=0; + if (rand_predictable) { + static unsigned char val = 0; - for (i=0; i= ENTROPY_NEEDED); - - st_idx=state_index; - st_num=state_num; - md_c[0] = md_count[0]; - md_c[1] = md_count[1]; - memcpy(local_md, md, sizeof md); - - state_index+=num; - if (state_index > state_num) - state_index %= state_num; - - /* state[st_idx], ..., state[(st_idx + num - 1) % st_num] - * are now ours (but other threads may use them too) */ - - md_count[0] += 1; - CRYPTO_w_unlock(CRYPTO_LOCK_RAND); - - while (num > 0) - { - j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num; - num-=j; - MD_Init(&m); -#ifndef GETPID_IS_MEANINGLESS - if (curr_pid) /* just in the first iteration to save time */ - { - MD_Update(&m,(unsigned char*)&curr_pid,sizeof curr_pid); - curr_pid = 0; - } + if (num <= 0) + return 1; + + m = EVP_MD_CTX_new(); + if (m == NULL) + goto err_mem; + + /* round upwards to multiple of MD_DIGEST_LENGTH/2 */ + num_ceil = + (1 + (num - 1) / (MD_DIGEST_LENGTH / 2)) * (MD_DIGEST_LENGTH / 2); + + /* + * (Based on the rand(3) manpage:) + * + * For each group of 10 bytes (or less), we do the following: + * + * Input into the hash function the local 'md' (which is initialized from + * the global 'md' before any bytes are generated), the bytes that are to + * be overwritten by the random bytes, and bytes from the 'state' + * (incrementing looping index). From this digest output (which is kept + * in 'md'), the top (up to) 10 bytes are returned to the caller and the + * bottom 10 bytes are xored into the 'state'. + * + * Finally, after we have finished 'num' random bytes for the + * caller, 'count' (which is incremented) and the local and global 'md' + * are fed into the hash function and the results are kept in the + * global 'md'. + */ + + CRYPTO_THREAD_run_once(&rand_lock_init, do_rand_lock_init); + CRYPTO_THREAD_write_lock(rand_lock); + /* + * We could end up in an async engine while holding this lock so ensure + * we don't pause and cause a deadlock + */ + ASYNC_block_pause(); + + /* prevent rand_bytes() from trying to obtain the lock again */ + CRYPTO_THREAD_write_lock(rand_tmp_lock); + locking_threadid = CRYPTO_THREAD_get_current_id(); + CRYPTO_THREAD_unlock(rand_tmp_lock); + crypto_lock_rand = 1; + + if (!initialized) { + RAND_poll(); + initialized = 1; + } + + if (!stirred_pool) + do_stir_pool = 1; + + ok = (entropy >= ENTROPY_NEEDED); + if (!ok) { + /* + * If the PRNG state is not yet unpredictable, then seeing the PRNG + * output may help attackers to determine the new state; thus we have + * to decrease the entropy estimate. Once we've had enough initial + * seeding we don't bother to adjust the entropy count, though, + * because we're not ambitious to provide *information-theoretic* + * randomness. NOTE: This approach fails if the program forks before + * we have enough entropy. Entropy should be collected in a separate + * input pool and be transferred to the output pool only when the + * entropy limit has been reached. + */ + entropy -= num; + if (entropy < 0) + entropy = 0; + } + + if (do_stir_pool) { + /* + * In the output function only half of 'md' remains secret, so we + * better make sure that the required entropy gets 'evenly + * distributed' through 'state', our randomness pool. The input + * function (rand_add) chains all of 'md', which makes it more + * suitable for this purpose. + */ + + int n = STATE_SIZE; /* so that the complete pool gets accessed */ + while (n > 0) { +#if MD_DIGEST_LENGTH > 20 +# error "Please adjust DUMMY_SEED." #endif - MD_Update(&m,&(local_md[MD_DIGEST_LENGTH/2]),MD_DIGEST_LENGTH/2); - MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)); -#ifndef PURIFY - MD_Update(&m,buf,j); /* purify complains */ +#define DUMMY_SEED "...................." /* at least MD_DIGEST_LENGTH */ + /* + * Note that the seed does not matter, it's just that + * rand_add expects to have something to hash. + */ + rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0); + n -= MD_DIGEST_LENGTH; + } + if (ok) + stirred_pool = 1; + } + + st_idx = state_index; + st_num = state_num; + md_c[0] = md_count[0]; + md_c[1] = md_count[1]; + memcpy(local_md, md, sizeof md); + + state_index += num_ceil; + if (state_index > state_num) + state_index %= state_num; + + /* + * state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num] are now + * ours (but other threads may use them too) + */ + + md_count[0] += 1; + + /* before unlocking, we must clear 'crypto_lock_rand' */ + crypto_lock_rand = 0; + ASYNC_unblock_pause(); + CRYPTO_THREAD_unlock(rand_lock); + + while (num > 0) { + /* num_ceil -= MD_DIGEST_LENGTH/2 */ + j = (num >= MD_DIGEST_LENGTH / 2) ? MD_DIGEST_LENGTH / 2 : num; + num -= j; + if (!MD_Init(m)) + goto err; +#ifndef GETPID_IS_MEANINGLESS + if (curr_pid) { /* just in the first iteration to save time */ + if (!MD_Update(m, (unsigned char *)&curr_pid, sizeof curr_pid)) + goto err; + curr_pid = 0; + } #endif - k=(st_idx+j)-st_num; - if (k > 0) - { - MD_Update(&m,&(state[st_idx]),j-k); - MD_Update(&m,&(state[0]),k); - } - else - MD_Update(&m,&(state[st_idx]),j); - MD_Final(local_md,&m); - - for (i=0; i= st_num) - st_idx=0; - } - } - - MD_Init(&m); - MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)); - MD_Update(&m,local_md,MD_DIGEST_LENGTH); - CRYPTO_w_lock(CRYPTO_LOCK_RAND); - MD_Update(&m,md,MD_DIGEST_LENGTH); - MD_Final(md,&m); - CRYPTO_w_unlock(CRYPTO_LOCK_RAND); - - memset(&m,0,sizeof(m)); - if (ok) - return(1); - else - { - RANDerr(RAND_F_SSLEAY_RAND_BYTES,RAND_R_PRNG_NOT_SEEDED); - return(0); - } - } - -/* pseudo-random bytes that are guaranteed to be unique but not - unpredictable */ -static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) - { - int ret, err; - - ret = RAND_bytes(buf, num); - if (ret == 0) - { - err = ERR_peek_error(); - if (ERR_GET_LIB(err) == ERR_LIB_RAND && - ERR_GET_REASON(err) == RAND_R_PRNG_NOT_SEEDED) - (void)ERR_get_error(); - } - return (ret); - } - -int RAND_status(void) - { - if (!initialized) - ssleay_rand_initialize(); - return (entropy >= ENTROPY_NEEDED); - } - -#ifdef WINDOWS -#include -#include + if (curr_time) { /* just in the first iteration to save time */ + if (!MD_Update(m, (unsigned char *)&curr_time, sizeof curr_time)) + goto err; + if (!MD_Update(m, (unsigned char *)&tv, sizeof tv)) + goto err; + curr_time = 0; + rand_hw_seed(m); + } + if (!MD_Update(m, local_md, MD_DIGEST_LENGTH)) + goto err; + if (!MD_Update(m, (unsigned char *)&(md_c[0]), sizeof(md_c))) + goto err; + + k = (st_idx + MD_DIGEST_LENGTH / 2) - st_num; + if (k > 0) { + if (!MD_Update(m, &(state[st_idx]), MD_DIGEST_LENGTH / 2 - k)) + goto err; + if (!MD_Update(m, &(state[0]), k)) + goto err; + } else if (!MD_Update(m, &(state[st_idx]), MD_DIGEST_LENGTH / 2)) + goto err; + if (!MD_Final(m, local_md)) + goto err; + + for (i = 0; i < MD_DIGEST_LENGTH / 2; i++) { + /* may compete with other threads */ + state[st_idx++] ^= local_md[i]; + if (st_idx >= st_num) + st_idx = 0; + if (i < j) + *(buf++) = local_md[i + MD_DIGEST_LENGTH / 2]; + } + } + + if (!MD_Init(m) + || !MD_Update(m, (unsigned char *)&(md_c[0]), sizeof(md_c)) + || !MD_Update(m, local_md, MD_DIGEST_LENGTH)) + goto err; + CRYPTO_THREAD_write_lock(rand_lock); + /* + * Prevent deadlocks if we end up in an async engine + */ + ASYNC_block_pause(); + if (!MD_Update(m, md, MD_DIGEST_LENGTH) || !MD_Final(m, md)) { + CRYPTO_THREAD_unlock(rand_lock); + goto err; + } + ASYNC_unblock_pause(); + CRYPTO_THREAD_unlock(rand_lock); + + EVP_MD_CTX_free(m); + if (ok) + return (1); + else if (pseudo) + return 0; + else { + RANDerr(RAND_F_RAND_BYTES, RAND_R_PRNG_NOT_SEEDED); + ERR_add_error_data(1, "You need to read the OpenSSL FAQ, " + "https://www.openssl.org/docs/faq.html"); + return (0); + } + err: + RANDerr(RAND_F_RAND_BYTES, ERR_R_EVP_LIB); + EVP_MD_CTX_free(m); + return 0; + err_mem: + RANDerr(RAND_F_RAND_BYTES, ERR_R_MALLOC_FAILURE); + EVP_MD_CTX_free(m); + return 0; -/***************************************************************************** - * Initialisation function for the SSL random generator. Takes the contents - * of the screen as random seed. - * - * Created 960901 by Gertjan van Oosten, gertjan@West.NL, West Consulting B.V. - * - * Code adapted from - * ; - * the original copyright message is: - * - * (C) Copyright Microsoft Corp. 1993. All rights reserved. - * - * You have a royalty-free right to use, modify, reproduce and - * distribute the Sample Files (and/or any modified version) in - * any way you find useful, provided that you agree that - * Microsoft has no warranty obligations or liability for any - * Sample Application Files which are modified. +} + +static int rand_nopseudo_bytes(unsigned char *buf, int num) +{ + return rand_bytes(buf, num, 0); +} + +#if OPENSSL_API_COMPAT < 0x10100000L +/* + * pseudo-random bytes that are guaranteed to be unique but not unpredictable */ +static int rand_pseudo_bytes(unsigned char *buf, int num) +{ + return rand_bytes(buf, num, 1); +} +#endif + +static int rand_status(void) +{ + CRYPTO_THREAD_ID cur; + int ret; + int do_not_lock; + + CRYPTO_THREAD_run_once(&rand_lock_init, do_rand_lock_init); + cur = CRYPTO_THREAD_get_current_id(); + /* + * check if we already have the lock (could happen if a RAND_poll() + * implementation calls RAND_status()) + */ + if (crypto_lock_rand) { + CRYPTO_THREAD_read_lock(rand_tmp_lock); + do_not_lock = CRYPTO_THREAD_compare_id(locking_threadid, cur); + CRYPTO_THREAD_unlock(rand_tmp_lock); + } else + do_not_lock = 0; + + if (!do_not_lock) { + CRYPTO_THREAD_write_lock(rand_lock); + /* + * Prevent deadlocks in case we end up in an async engine + */ + ASYNC_block_pause(); + + /* + * prevent rand_bytes() from trying to obtain the lock again + */ + CRYPTO_THREAD_write_lock(rand_tmp_lock); + locking_threadid = cur; + CRYPTO_THREAD_unlock(rand_tmp_lock); + crypto_lock_rand = 1; + } + + if (!initialized) { + RAND_poll(); + initialized = 1; + } + + ret = entropy >= ENTROPY_NEEDED; + + if (!do_not_lock) { + /* before unlocking, we must clear 'crypto_lock_rand' */ + crypto_lock_rand = 0; + + ASYNC_unblock_pause(); + CRYPTO_THREAD_unlock(rand_lock); + } + + return ret; +} + /* - * I have modified the loading of bytes via RAND_seed() mechanism since - * the original would have been very very CPU intensive since RAND_seed() - * does an MD5 per 16 bytes of input. The cost to digest 16 bytes is the same - * as that to digest 56 bytes. So under the old system, a screen of - * 1024*768*256 would have been CPU cost of approximately 49,000 56 byte MD5 - * digests or digesting 2.7 mbytes. What I have put in place would - * be 48 16k MD5 digests, or effectively 48*16+48 MD5 bytes or 816 kbytes - * or about 3.5 times as much. - * - eric + * rand_hw_seed: get seed data from any available hardware RNG. only + * currently supports rdrand. */ -void RAND_screen(void) + +/* Adapted from eng_rdrand.c */ + +#if (defined(__i386) || defined(__i386__) || defined(_M_IX86) || \ + defined(__x86_64) || defined(__x86_64__) || \ + defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ) \ + && !defined(OPENSSL_NO_RDRAND) + +# define RDRAND_CALLS 4 + +size_t OPENSSL_ia32_rdrand(void); +extern unsigned int OPENSSL_ia32cap_P[]; + +static void rand_hw_seed(EVP_MD_CTX *ctx) +{ + int i; + if (!(OPENSSL_ia32cap_P[1] & (1 << (62 - 32)))) + return; + for (i = 0; i < RDRAND_CALLS; i++) { + size_t rnd; + rnd = OPENSSL_ia32_rdrand(); + if (rnd == 0) + return; + MD_Update(ctx, (unsigned char *)&rnd, sizeof(size_t)); + } +} + +/* XOR an existing buffer with random data */ + +void rand_hw_xor(unsigned char *buf, size_t num) +{ + size_t rnd; + if (!(OPENSSL_ia32cap_P[1] & (1 << (62 - 32)))) + return; + while (num >= sizeof(size_t)) { + rnd = OPENSSL_ia32_rdrand(); + if (rnd == 0) + return; + *((size_t *)buf) ^= rnd; + buf += sizeof(size_t); + num -= sizeof(size_t); + } + if (num) { + rnd = OPENSSL_ia32_rdrand(); + if (rnd == 0) + return; + while (num) { + *buf ^= rnd & 0xff; + rnd >>= 8; + buf++; + num--; + } + } +} + +#else + +static void rand_hw_seed(EVP_MD_CTX *ctx) { - HDC hScrDC; /* screen DC */ - HDC hMemDC; /* memory DC */ - HBITMAP hBitmap; /* handle for our bitmap */ - HBITMAP hOldBitmap; /* handle for previous bitmap */ - BITMAP bm; /* bitmap properties */ - unsigned int size; /* size of bitmap */ - char *bmbits; /* contents of bitmap */ - int w; /* screen width */ - int h; /* screen height */ - int y; /* y-coordinate of screen lines to grab */ - int n = 16; /* number of screen lines to grab at a time */ - - /* Create a screen DC and a memory DC compatible to screen DC */ - hScrDC = CreateDC("DISPLAY", NULL, NULL, NULL); - hMemDC = CreateCompatibleDC(hScrDC); - - /* Get screen resolution */ - w = GetDeviceCaps(hScrDC, HORZRES); - h = GetDeviceCaps(hScrDC, VERTRES); - - /* Create a bitmap compatible with the screen DC */ - hBitmap = CreateCompatibleBitmap(hScrDC, w, n); - - /* Select new bitmap into memory DC */ - hOldBitmap = SelectObject(hMemDC, hBitmap); - - /* Get bitmap properties */ - GetObject(hBitmap, sizeof(BITMAP), (LPSTR)&bm); - size = (unsigned int)bm.bmWidthBytes * bm.bmHeight * bm.bmPlanes; - - bmbits = Malloc(size); - if (bmbits) { - /* Now go through the whole screen, repeatedly grabbing n lines */ - for (y = 0; y < h-n; y += n) - { - unsigned char md[MD_DIGEST_LENGTH]; - - /* Bitblt screen DC to memory DC */ - BitBlt(hMemDC, 0, 0, w, n, hScrDC, 0, y, SRCCOPY); - - /* Copy bitmap bits from memory DC to bmbits */ - GetBitmapBits(hBitmap, size, bmbits); - - /* Get the MD5 of the bitmap */ - MD(bmbits,size,md); - - /* Seed the random generator with the MD5 digest */ - RAND_seed(md, MD_DIGEST_LENGTH); - } - - Free(bmbits); - } - - /* Select old bitmap back into memory DC */ - hBitmap = SelectObject(hMemDC, hOldBitmap); - - /* Clean up */ - DeleteObject(hBitmap); - DeleteDC(hMemDC); - DeleteDC(hScrDC); + return; } + +void rand_hw_xor(unsigned char *buf, size_t num) +{ + return; +} + #endif