X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Fmd_rand.c;h=668da9549997cc9b2586331d05ef4e574b1f8e48;hp=b1d51e890b70ba2cb4586c537a11a195b7c2a9d7;hb=3b3bc455d0a670b835a37996f35651b83b52d8df;hpb=a6aa71ff5f321d762c31da4caca31e375842653b diff --git a/crypto/rand/md_rand.c b/crypto/rand/md_rand.c index b1d51e890b..668da95499 100644 --- a/crypto/rand/md_rand.c +++ b/crypto/rand/md_rand.c @@ -109,9 +109,9 @@ * */ -#define ENTROPY_NEEDED 16 /* require 128 bits = 16 bytes of randomness */ +#define ENTROPY_NEEDED 20 /* require 160 bits = 20 bytes of randomness */ -#ifndef MD_RAND_DEBUG +#ifdef MD_RAND_DEBUG # ifndef NDEBUG # define NDEBUG # endif @@ -359,7 +359,7 @@ static void ssleay_rand_seed(const void *buf, int num) ssleay_rand_add(buf, num, num); } -static void ssleay_rand_initialize(void) +static void ssleay_rand_initialize(void) /* not exported in RAND_METHOD */ { unsigned long l; #ifndef GETPID_IS_MEANINGLESS @@ -411,6 +411,7 @@ static void ssleay_rand_initialize(void) static int ssleay_rand_bytes(unsigned char *buf, int num) { + static volatile int stirred_pool = 0; int i,j,k,st_num,st_idx; int ok; long md_c[2]; @@ -419,6 +420,7 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) #ifndef GETPID_IS_MEANINGLESS pid_t curr_pid = getpid(); #endif + int do_stir_pool = 0; #ifdef PREDICT if (rand_predictable) @@ -455,6 +457,9 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) if (!initialized) ssleay_rand_initialize(); + if (!stirred_pool) + do_stir_pool = 1; + ok = (entropy >= ENTROPY_NEEDED); if (!ok) { @@ -464,12 +469,42 @@ 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) + { + /* 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) + { +#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]; @@ -536,6 +571,8 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) 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); } } @@ -559,146 +596,15 @@ 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); - } + int ret; -#ifdef WINDOWS -#include -#include - -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; - } + CRYPTO_w_lock(CRYPTO_LOCK_RAND); - 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); + if (!initialized) + ssleay_rand_initialize(); + ret = entropy >= ENTROPY_NEEDED; - return (RAND_status()); - } + CRYPTO_w_unlock(CRYPTO_LOCK_RAND); -/***************************************************************************** - * 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); + return ret; } - - Free(bmbits); - } - - /* Select old bitmap back into memory DC */ - hBitmap = SelectObject(hMemDC, hOldBitmap); - - /* Clean up */ - DeleteObject(hBitmap); - DeleteDC(hMemDC); - DeleteDC(hScrDC); -} -#endif