X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Fmd_rand.c;h=d167dea77db6485bd14427dfb78bb3c6e8c9b1d5;hp=729484fe9275b20d7dd8bee5d9fadf595b69b908;hb=28e5428d5df083c6015be5abc88959ee2e662eb6;hpb=62ac2938015939e2ef30f12295f0ee59ff79c11b diff --git a/crypto/rand/md_rand.c b/crypto/rand/md_rand.c index 729484fe92..d167dea77d 100644 --- a/crypto/rand/md_rand.c +++ b/crypto/rand/md_rand.c @@ -55,8 +55,61 @@ * copied and put under another distribution licence * [including the GNU Public Licence.] */ +/* ==================================================================== + * Copyright (c) 1998-2000 The OpenSSL Project. All rights reserved. + * + * 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 above 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 acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * openssl-core@openssl.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.openssl.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED 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 OpenSSL PROJECT OR + * ITS 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. + * ==================================================================== + * + * This product includes cryptographic software written by Eric Young + * (eay@cryptsoft.com). This product includes software written by Tim + * Hudson (tjh@cryptsoft.com). + * + */ -#ifndef MD_RAND_DEBUG +#ifdef MD_RAND_DEBUG # ifndef NDEBUG # define NDEBUG # endif @@ -64,70 +117,20 @@ #include #include -#include #include #include "openssl/e_os.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 -#endif -#endif +#include +#include "rand_lcl.h" -/* 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 - */ +#include +#include -#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) +#ifdef BN_DEBUG +# define PREDICT #endif -#include - -/* #define NORAND 1 */ /* #define PREDICT 1 */ #define STATE_SIZE 1023 @@ -135,17 +138,34 @@ 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; + +/* This should be set to 1 only when ssleay_rand_add() is called inside + an already locked state, so it doesn't try to lock and thereby cause + a hang. And it should always be reset back to 0 before unlocking. */ +static int add_do_not_lock=0; + +#ifdef PREDICT +int rand_predictable=0; +#endif 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_bytes(unsigned char *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); +static int ssleay_rand_status(void); RAND_METHOD rand_ssleay_meth={ ssleay_rand_seed, ssleay_rand_bytes, ssleay_rand_cleanup, + ssleay_rand_add, + ssleay_rand_pseudo_bytes, + ssleay_rand_status }; RAND_METHOD *RAND_SSLeay(void) @@ -161,34 +181,33 @@ static void ssleay_rand_cleanup(void) memset(md,0,MD_DIGEST_LENGTH); md_count[0]=0; md_count[1]=0; + entropy=0; + initialized=0; } -static void ssleay_rand_seed(const void *buf, int num) +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 - /* - * (Based on doc/ssleay.txt, section rand.doc:) + * (Based on the rand(3) manpage) * - * The input is chopped up into units of 16 bytes (or less for - * the last block). Each of these blocks is run through the MD5 - * message digest as follow: The data passed to the MD5 digest + * 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 MD5. + * 'state' at the same locations that were used as input into the + * hash function. */ - CRYPTO_w_lock(CRYPTO_LOCK_RAND); + if (!add_do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND); st_idx=state_index; /* use our own copies of the counters so that even @@ -220,7 +239,7 @@ static void ssleay_rand_seed(const void *buf, int num) md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0); - CRYPTO_w_unlock(CRYPTO_LOCK_RAND); + if (!add_do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND); for (i=0; i= ENTROPY_NEEDED); + if (!ok) { - CRYPTO_w_unlock(CRYPTO_LOCK_RAND); - /* put in some default random data, we need more than - * just this */ - RAND_seed(&m,sizeof(m)); -#ifndef MSDOS - l=curr_pid; - RAND_seed(&l,sizeof(l)); - l=getuid(); - RAND_seed(&l,sizeof(l)); -#endif - l=time(NULL); - RAND_seed(&l,sizeof(l)); - -#ifdef DEVRANDOM - /* - * Use a random entropy pool device. - * Linux 1.3.x and FreeBSD-Current has - * this. Use /dev/urandom if you can - * as /dev/random will block if it runs out - * of random entries. + /* 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. */ - if ((fh = fopen(DEVRANDOM, "r")) != NULL) + entropy -= num; + if (entropy < 0) + entropy = 0; + } + + if (do_stir_pool) + { + /* Our output function chains only half of 'md', so we better + * make sure that the required entropy gets 'evenly distributed' + * through 'state', our randomness pool. The input function + * (ssleay_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) { - unsigned char tmpbuf[32]; - - fread((unsigned char *)tmpbuf,1,32,fh); - /* we don't care how many bytes we read, - * we will just copy the 'stack' if there is - * nothing else :-) */ - fclose(fh); - RAND_seed(tmpbuf,32); - memset(tmpbuf,0,32); - } -#endif -#ifdef PURIFY - memset(state,0,STATE_SIZE); - memset(md,0,MD_DIGEST_LENGTH); +#if MD_DIGEST_LENGTH > 20 +# error "Please adjust DUMMY_SEED." #endif - CRYPTO_w_lock(CRYPTO_LOCK_RAND); - init=0; +#define DUMMY_SEED "...................." /* at least MD_DIGEST_LENGTH */ + /* Note that the seed does not matter, it's just that + * ssleay_rand_add expects to have something to hash. */ + ssleay_rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0); + n -= MD_DIGEST_LENGTH; + } + if (ok) + stirred_pool = 1; } st_idx=state_index; @@ -379,6 +417,9 @@ static void ssleay_rand_bytes(unsigned char *buf, int num) * are now ours (but other threads may use them too) */ md_count[0] += 1; + + add_do_not_lock = 0; /* If this would ever be forgotten, we can + expect any evil god to eat our souls. */ CRYPTO_w_unlock(CRYPTO_LOCK_RAND); while (num > 0) @@ -386,7 +427,7 @@ static void ssleay_rand_bytes(unsigned char *buf, int num) j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num; num-=j; MD_Init(&m); -#ifndef MSDOS +#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); @@ -426,102 +467,45 @@ static void ssleay_rand_bytes(unsigned char *buf, int num) 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); + ERR_add_error_data(1, "You need to read the OpenSSL FAQ, " + "http://www.openssl.org/support/faq.html"); + return(0); + } } -#ifdef WINDOWS -#include -#include +/* 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; -/***************************************************************************** - * 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. - */ -/* - * I have modified the loading of bytes via RAND_seed() mechanism since - * the origional 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 approximatly 49,000 56 byte MD5 - * digests or digesting 2.7 mbytes. What I have put in place would - * be 48 16k MD5 digests, or efectivly 48*16+48 MD5 bytes or 816 kbytes - * or about 3.5 times as much. - * - eric - */ -void RAND_screen(void) -{ - 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); + 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); } - Free(bmbits); - } +static int ssleay_rand_status(void) + { + int ret; - /* Select old bitmap back into memory DC */ - hBitmap = SelectObject(hMemDC, hOldBitmap); + if (!initialized) + RAND_poll(); - /* Clean up */ - DeleteObject(hBitmap); - DeleteDC(hMemDC); - DeleteDC(hScrDC); -} -#endif + CRYPTO_w_lock(CRYPTO_LOCK_RAND); + initialized = 1; + ret = entropy >= ENTROPY_NEEDED; + CRYPTO_w_unlock(CRYPTO_LOCK_RAND); + + return ret; + }