X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Fmd_rand.c;h=a00ed70718589c74e2ef76dd3e9a9c9736783f68;hp=35bdbeb73ee3382be30a8b38321c808f7266ef01;hb=f9b0f47c0cf1db34360eac3ad783f4670238c430;hpb=f3f3cc0ccaf528767942e6d151383209394cd7c4 diff --git a/crypto/rand/md_rand.c b/crypto/rand/md_rand.c index 35bdbeb73e..a00ed70718 100644 --- a/crypto/rand/md_rand.c +++ b/crypto/rand/md_rand.c @@ -1,4 +1,4 @@ -* crypto/rand/md_rand.c */ +/* crypto/rand/md_rand.c */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * @@ -56,7 +56,7 @@ * [including the GNU Public Licence.] */ /* ==================================================================== - * Copyright (c) 1998-2000 The OpenSSL Project. All rights reserved. + * Copyright (c) 1998-2001 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 @@ -109,9 +109,7 @@ * */ -#define ENTROPY_NEEDED 16 /* require 128 bits = 16 bytes of randomness */ - -#ifndef MD_RAND_DEBUG +#ifdef MD_RAND_DEBUG # ifndef NDEBUG # define NDEBUG # endif @@ -119,75 +117,20 @@ #include #include -#include #include -#include "openssl/e_os.h" +#include "e_os.h" + +#include +#include "rand_lcl.h" #include #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 - -/* 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 - */ - -#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 - -#include - #ifdef BN_DEBUG # define PREDICT #endif -/* #define NORAND 1 */ /* #define PREDICT 1 */ #define STATE_SIZE 1023 @@ -198,6 +141,13 @@ static long md_count[2]={0,0}; static double entropy=0; static int initialized=0; +static unsigned int crypto_lock_rand = 0; /* may be set only when a thread + * holds CRYPTO_LOCK_RAND + * (to prevent double locking) */ +/* access to lockin_thread is synchronized by CRYPTO_LOCK_RAND2 */ +static unsigned long locking_thread = 0; /* valid iff crypto_lock_rand is set */ + + #ifdef PREDICT int rand_predictable=0; #endif @@ -234,6 +184,7 @@ static void ssleay_rand_cleanup(void) md_count[0]=0; md_count[1]=0; entropy=0; + initialized=0; } static void ssleay_rand_add(const void *buf, int num, double add) @@ -241,11 +192,8 @@ 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 + EVP_MD_CTX m; + int do_not_lock; /* * (Based on the rand(3) manpage) @@ -262,7 +210,17 @@ static void ssleay_rand_add(const void *buf, int num, double add) * hash function. */ - CRYPTO_w_lock(CRYPTO_LOCK_RAND); + /* check if we already have the lock */ + if (crypto_lock_rand) + { + CRYPTO_r_lock(CRYPTO_LOCK_RAND2); + do_not_lock = (locking_thread == CRYPTO_thread_id()); + CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); + } + else + do_not_lock = 0; + + if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND); st_idx=state_index; /* use our own copies of the counters so that even @@ -294,8 +252,9 @@ static void ssleay_rand_add(const void *buf, int num, double add) md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0); - CRYPTO_w_unlock(CRYPTO_LOCK_RAND); + if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND); + EVP_MD_CTX_init(&m); for (i=0; i= ENTROPY_NEEDED); if (!ok) { @@ -464,30 +394,64 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) * 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 (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) + { +#if MD_DIGEST_LENGTH > 20 +# error "Please adjust DUMMY_SEED." +#endif +#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; 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; + state_index+=num_ceil; if (state_index > state_num) state_index %= state_num; - /* state[st_idx], ..., state[(st_idx + num - 1) % st_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; CRYPTO_w_unlock(CRYPTO_LOCK_RAND); while (num > 0) { + /* num_ceil -= MD_DIGEST_LENGTH/2 */ j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num; num-=j; MD_Init(&m); @@ -498,27 +462,28 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) curr_pid = 0; } #endif - MD_Update(&m,&(local_md[MD_DIGEST_LENGTH/2]),MD_DIGEST_LENGTH/2); + MD_Update(&m,local_md,MD_DIGEST_LENGTH); MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)); #ifndef PURIFY MD_Update(&m,buf,j); /* purify complains */ #endif - k=(st_idx+j)-st_num; + k=(st_idx+MD_DIGEST_LENGTH/2)-st_num; if (k > 0) { - MD_Update(&m,&(state[st_idx]),j-k); + MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2-k); MD_Update(&m,&(state[0]),k); } else - MD_Update(&m,&(state[st_idx]),j); - MD_Final(local_md,&m); + MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2); + MD_Final(&m,local_md); - for (i=0; i= st_num) st_idx=0; + if (i < j) + *(buf++)=local_md[i+MD_DIGEST_LENGTH/2]; } } @@ -527,15 +492,17 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) 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); + MD_Final(&m,md); CRYPTO_w_unlock(CRYPTO_LOCK_RAND); - memset(&m,0,sizeof(m)); + EVP_MD_CTX_cleanup(&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); } } @@ -544,7 +511,8 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) unpredictable */ static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) { - int ret, err; + int ret; + unsigned long err; ret = RAND_bytes(buf, num); if (ret == 0) @@ -559,146 +527,46 @@ static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) static int ssleay_rand_status(void) { - if (!initialized) - ssleay_rand_initialize(); - return (entropy >= ENTROPY_NEEDED); - } - -#ifdef WINDOWS -#include -#include + int ret; + int do_not_lock; -int RAND_event(UINT iMsg, WPARAM wParam, LPARAM lParam) - { - double add_entropy=0; - SYSTEMTIME t; - - switch (iMsg) - { - case WM_KEYDOWN: - { - static WPARAM key; - if (key != wParam) - add_entropy = 0.05; - key = wParam; - } - break; - case WM_MOUSEMOVE: - { - static int lastx,lasty,lastdx,lastdy; - int x,y,dx,dy; - - x=LOWORD(lParam); - y=HIWORD(lParam); - dx=lastx-x; - dy=lasty-y; - if (dx != 0 && dy != 0 && dx-lastdx != 0 && dy-lastdy != 0) - add_entropy=.2; - lastx=x, lasty=y; - lastdx=dx, lastdy=dy; - } - break; + /* check if we already have the lock + * (could happen if a RAND_poll() implementation calls RAND_status()) */ + if (crypto_lock_rand) + { + CRYPTO_r_lock(CRYPTO_LOCK_RAND2); + do_not_lock = (locking_thread == CRYPTO_thread_id()); + CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); + } + else + do_not_lock = 0; + + if (!do_not_lock) + { + CRYPTO_w_lock(CRYPTO_LOCK_RAND); + + /* prevent ssleay_rand_bytes() from trying to obtain the lock again */ + CRYPTO_w_lock(CRYPTO_LOCK_RAND2); + locking_thread = CRYPTO_thread_id(); + CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); + crypto_lock_rand = 1; + } + + if (!initialized) + { + RAND_poll(); + initialized = 1; } - GetSystemTime(&t); - RAND_add(&iMsg, sizeof(iMsg), add_entropy); - RAND_add(&wParam, sizeof(wParam), 0); - RAND_add(&lParam, sizeof(lParam), 0); - RAND_add(&t, sizeof(t), 0); - - return (RAND_status()); - } + ret = entropy >= ENTROPY_NEEDED; -/***************************************************************************** - * 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 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 - */ -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); + if (!do_not_lock) + { + /* before unlocking, we must clear 'crypto_lock_rand' */ + crypto_lock_rand = 0; + + CRYPTO_w_unlock(CRYPTO_LOCK_RAND); + } + + return ret; } - - Free(bmbits); - } - - /* Select old bitmap back into memory DC */ - hBitmap = SelectObject(hMemDC, hOldBitmap); - - /* Clean up */ - DeleteObject(hBitmap); - DeleteDC(hMemDC); - DeleteDC(hScrDC); -} -#endif