1 /* crypto/rand/md_rand.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
59 #define ENTROPY_NEEDED 16 /* require 128 bits = 16 bytes of randomness */
72 #include "openssl/e_os.h"
74 #include <openssl/crypto.h>
75 #include <openssl/err.h>
77 #if !defined(USE_MD5_RAND) && !defined(USE_SHA1_RAND) && !defined(USE_MDC2_RAND) && !defined(USE_MD2_RAND)
78 #if !defined(NO_SHA) && !defined(NO_SHA1)
80 #elif !defined(NO_MD5)
82 #elif !defined(NO_MDC2) && !defined(NO_DES)
84 #elif !defined(NO_MD2)
87 #error No message digest algorithm available
91 /* Changed how the state buffer used. I now attempt to 'wrap' such
92 * that I don't run over the same locations the next time go through
93 * the 1023 bytes - many thanks to
94 * Robert J. LeBlanc <rjl@renaissoft.com> for his comments
97 #if defined(USE_MD5_RAND)
98 #include <openssl/md5.h>
99 #define MD_DIGEST_LENGTH MD5_DIGEST_LENGTH
100 #define MD_CTX MD5_CTX
101 #define MD_Init(a) MD5_Init(a)
102 #define MD_Update(a,b,c) MD5_Update(a,b,c)
103 #define MD_Final(a,b) MD5_Final(a,b)
104 #define MD(a,b,c) MD5(a,b,c)
105 #elif defined(USE_SHA1_RAND)
106 #include <openssl/sha.h>
107 #define MD_DIGEST_LENGTH SHA_DIGEST_LENGTH
108 #define MD_CTX SHA_CTX
109 #define MD_Init(a) SHA1_Init(a)
110 #define MD_Update(a,b,c) SHA1_Update(a,b,c)
111 #define MD_Final(a,b) SHA1_Final(a,b)
112 #define MD(a,b,c) SHA1(a,b,c)
113 #elif defined(USE_MDC2_RAND)
114 #include <openssl/mdc2.h>
115 #define MD_DIGEST_LENGTH MDC2_DIGEST_LENGTH
116 #define MD_CTX MDC2_CTX
117 #define MD_Init(a) MDC2_Init(a)
118 #define MD_Update(a,b,c) MDC2_Update(a,b,c)
119 #define MD_Final(a,b) MDC2_Final(a,b)
120 #define MD(a,b,c) MDC2(a,b,c)
121 #elif defined(USE_MD2_RAND)
122 #include <openssl/md2.h>
123 #define MD_DIGEST_LENGTH MD2_DIGEST_LENGTH
124 #define MD_CTX MD2_CTX
125 #define MD_Init(a) MD2_Init(a)
126 #define MD_Update(a,b,c) MD2_Update(a,b,c)
127 #define MD_Final(a,b) MD2_Final(a,b)
128 #define MD(a,b,c) MD2(a,b,c)
131 #include <openssl/rand.h>
133 /* #define NORAND 1 */
134 /* #define PREDICT 1 */
136 #define STATE_SIZE 1023
137 static int state_num=0,state_index=0;
138 static unsigned char state[STATE_SIZE+MD_DIGEST_LENGTH];
139 static unsigned char md[MD_DIGEST_LENGTH];
140 static long md_count[2]={0,0};
141 static double entropy=0;
142 static int initialized=0;
144 const char *RAND_version="RAND" OPENSSL_VERSION_PTEXT;
146 static void ssleay_rand_cleanup(void);
147 static void ssleay_rand_seed(const void *buf, int num);
148 static void ssleay_rand_add(const void *buf, int num, double add_entropy);
149 static int ssleay_rand_bytes(unsigned char *buf, int num);
150 static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num);
152 RAND_METHOD rand_ssleay_meth={
157 ssleay_rand_pseudo_bytes,
160 RAND_METHOD *RAND_SSLeay(void)
162 return(&rand_ssleay_meth);
165 static void ssleay_rand_cleanup(void)
167 memset(state,0,sizeof(state));
170 memset(md,0,MD_DIGEST_LENGTH);
176 static void ssleay_rand_add(const void *buf, int num, double add)
180 unsigned char local_md[MD_DIGEST_LENGTH];
188 * (Based on the rand(3) manpage)
190 * The input is chopped up into units of 20 bytes (or less for
191 * the last block). Each of these blocks is run through the hash
192 * function as follows: The data passed to the hash function
193 * is the current 'md', the same number of bytes from the 'state'
194 * (the location determined by in incremented looping index) as
195 * the current 'block', the new key data 'block', and 'count'
196 * (which is incremented after each use).
197 * The result of this is kept in 'md' and also xored into the
198 * 'state' at the same locations that were used as input into the
202 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
205 /* use our own copies of the counters so that even
206 * if a concurrent thread seeds with exactly the
207 * same data and uses the same subarray there's _some_
209 md_c[0] = md_count[0];
210 md_c[1] = md_count[1];
212 memcpy(local_md, md, sizeof md);
214 /* state_index <= state_num <= STATE_SIZE */
216 if (state_index >= STATE_SIZE)
218 state_index%=STATE_SIZE;
219 state_num=STATE_SIZE;
221 else if (state_num < STATE_SIZE)
223 if (state_index > state_num)
224 state_num=state_index;
226 /* state_index <= state_num <= STATE_SIZE */
228 /* state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE]
229 * are what we will use now, but other threads may use them
232 md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0);
234 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
236 for (i=0; i<num; i+=MD_DIGEST_LENGTH)
239 j=(j > MD_DIGEST_LENGTH)?MD_DIGEST_LENGTH:j;
242 MD_Update(&m,local_md,MD_DIGEST_LENGTH);
243 k=(st_idx+j)-STATE_SIZE;
246 MD_Update(&m,&(state[st_idx]),j-k);
247 MD_Update(&m,&(state[0]),k);
250 MD_Update(&m,&(state[st_idx]),j);
253 MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
254 MD_Final(local_md,&m);
257 buf=(const char *)buf + j;
261 /* Parallel threads may interfere with this,
262 * but always each byte of the new state is
263 * the XOR of some previous value of its
264 * and local_md (itermediate values may be lost).
265 * Alway using locking could hurt performance more
266 * than necessary given that conflicts occur only
267 * when the total seeding is longer than the random
269 state[st_idx++]^=local_md[k];
270 if (st_idx >= STATE_SIZE)
274 memset((char *)&m,0,sizeof(m));
276 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
277 /* Don't just copy back local_md into md -- this could mean that
278 * other thread's seeding remains without effect (except for
279 * the incremented counter). By XORing it we keep at least as
280 * much entropy as fits into md. */
281 for (k = 0; k < sizeof md; k++)
283 md[k] ^= local_md[k];
285 if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */
287 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
290 assert(md_c[1] == md_count[1]);
294 static void ssleay_rand_seed(const void *buf, int num)
296 ssleay_rand_add(buf, num, num);
299 static void ssleay_rand_initialize(void)
302 #ifndef GETPID_IS_MEANINGLESS
303 pid_t curr_pid = getpid();
309 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
310 /* put in some default random data, we need more than just this */
311 #ifndef GETPID_IS_MEANINGLESS
313 RAND_add(&l,sizeof(l),0);
315 RAND_add(&l,sizeof(l),0);
318 RAND_add(&l,sizeof(l),0);
321 /* Use a random entropy pool device. Linux, FreeBSD and OpenBSD
322 * have this. Use /dev/urandom if you can as /dev/random may block
323 * if it runs out of random entries. */
325 if ((fh = fopen(DEVRANDOM, "r")) != NULL)
327 unsigned char tmpbuf[ENTROPY_NEEDED];
330 setvbuf(fh, NULL, _IONBF, 0);
331 n=fread((unsigned char *)tmpbuf,1,ENTROPY_NEEDED,fh);
333 RAND_add(tmpbuf,sizeof tmpbuf,n);
338 memset(state,0,STATE_SIZE);
339 memset(md,0,MD_DIGEST_LENGTH);
341 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
345 static int ssleay_rand_bytes(unsigned char *buf, int num)
347 int i,j,k,st_num,st_idx;
350 unsigned char local_md[MD_DIGEST_LENGTH];
352 #ifndef GETPID_IS_MEANINGLESS
353 pid_t curr_pid = getpid();
358 static unsigned char val=0;
360 for (i=0; i<num; i++)
367 * (Based on the rand(3) manpage:)
369 * For each group of 10 bytes (or less), we do the following:
371 * Input into the hash function the top 10 bytes from the
372 * local 'md' (which is initialized from the global 'md'
373 * before any bytes are generated), the bytes that are
374 * to be overwritten by the random bytes, and bytes from the
375 * 'state' (incrementing looping index). From this digest output
376 * (which is kept in 'md'), the top (up to) 10 bytes are
377 * returned to the caller and the bottom (up to) 10 bytes are xored
379 * Finally, after we have finished 'num' random bytes for the
380 * caller, 'count' (which is incremented) and the local and global 'md'
381 * are fed into the hash function and the results are kept in the
385 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
388 ssleay_rand_initialize();
390 ok = (entropy >= ENTROPY_NEEDED);
393 /* If the PRNG state is not yet unpredictable, then seeing
394 * the PRNG output may help attackers to determine the new
395 * state; thus we have to decrease the entropy estimate.
396 * Once we've had enough initial seeding we don't bother to
397 * adjust the entropy count, though, because we're not ambitious
398 * to provide *information-theoretic* randomness.
407 md_c[0] = md_count[0];
408 md_c[1] = md_count[1];
409 memcpy(local_md, md, sizeof md);
412 if (state_index > state_num)
413 state_index %= state_num;
415 /* state[st_idx], ..., state[(st_idx + num - 1) % st_num]
416 * are now ours (but other threads may use them too) */
419 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
423 j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num;
426 #ifndef GETPID_IS_MEANINGLESS
427 if (curr_pid) /* just in the first iteration to save time */
429 MD_Update(&m,(unsigned char*)&curr_pid,sizeof curr_pid);
433 MD_Update(&m,&(local_md[MD_DIGEST_LENGTH/2]),MD_DIGEST_LENGTH/2);
434 MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
436 MD_Update(&m,buf,j); /* purify complains */
441 MD_Update(&m,&(state[st_idx]),j-k);
442 MD_Update(&m,&(state[0]),k);
445 MD_Update(&m,&(state[st_idx]),j);
446 MD_Final(local_md,&m);
450 state[st_idx++]^=local_md[i]; /* may compete with other threads */
451 *(buf++)=local_md[i+MD_DIGEST_LENGTH/2];
452 if (st_idx >= st_num)
458 MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
459 MD_Update(&m,local_md,MD_DIGEST_LENGTH);
460 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
461 MD_Update(&m,md,MD_DIGEST_LENGTH);
463 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
465 memset(&m,0,sizeof(m));
470 RANDerr(RAND_F_SSLEAY_RAND_BYTES,RAND_R_PRNG_NOT_SEEDED);
475 /* pseudo-random bytes that are guaranteed to be unique but not
477 static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num)
481 ret = RAND_bytes(buf, num);
484 err = ERR_peek_error();
485 if (ERR_GET_LIB(err) == ERR_LIB_RAND &&
486 ERR_GET_REASON(err) == RAND_R_PRNG_NOT_SEEDED)
487 (void)ERR_get_error();
492 int RAND_status(void)
495 ssleay_rand_initialize();
496 return (entropy >= ENTROPY_NEEDED);
501 #include <openssl/rand.h>
503 /*****************************************************************************
504 * Initialisation function for the SSL random generator. Takes the contents
505 * of the screen as random seed.
507 * Created 960901 by Gertjan van Oosten, gertjan@West.NL, West Consulting B.V.
510 * <URL:http://www.microsoft.com/kb/developr/win_dk/q97193.htm>;
511 * the original copyright message is:
513 * (C) Copyright Microsoft Corp. 1993. All rights reserved.
515 * You have a royalty-free right to use, modify, reproduce and
516 * distribute the Sample Files (and/or any modified version) in
517 * any way you find useful, provided that you agree that
518 * Microsoft has no warranty obligations or liability for any
519 * Sample Application Files which are modified.
522 * I have modified the loading of bytes via RAND_seed() mechanism since
523 * the original would have been very very CPU intensive since RAND_seed()
524 * does an MD5 per 16 bytes of input. The cost to digest 16 bytes is the same
525 * as that to digest 56 bytes. So under the old system, a screen of
526 * 1024*768*256 would have been CPU cost of approximately 49,000 56 byte MD5
527 * digests or digesting 2.7 mbytes. What I have put in place would
528 * be 48 16k MD5 digests, or effectively 48*16+48 MD5 bytes or 816 kbytes
529 * or about 3.5 times as much.
532 void RAND_screen(void)
534 HDC hScrDC; /* screen DC */
535 HDC hMemDC; /* memory DC */
536 HBITMAP hBitmap; /* handle for our bitmap */
537 HBITMAP hOldBitmap; /* handle for previous bitmap */
538 BITMAP bm; /* bitmap properties */
539 unsigned int size; /* size of bitmap */
540 char *bmbits; /* contents of bitmap */
541 int w; /* screen width */
542 int h; /* screen height */
543 int y; /* y-coordinate of screen lines to grab */
544 int n = 16; /* number of screen lines to grab at a time */
546 /* Create a screen DC and a memory DC compatible to screen DC */
547 hScrDC = CreateDC("DISPLAY", NULL, NULL, NULL);
548 hMemDC = CreateCompatibleDC(hScrDC);
550 /* Get screen resolution */
551 w = GetDeviceCaps(hScrDC, HORZRES);
552 h = GetDeviceCaps(hScrDC, VERTRES);
554 /* Create a bitmap compatible with the screen DC */
555 hBitmap = CreateCompatibleBitmap(hScrDC, w, n);
557 /* Select new bitmap into memory DC */
558 hOldBitmap = SelectObject(hMemDC, hBitmap);
560 /* Get bitmap properties */
561 GetObject(hBitmap, sizeof(BITMAP), (LPSTR)&bm);
562 size = (unsigned int)bm.bmWidthBytes * bm.bmHeight * bm.bmPlanes;
564 bmbits = Malloc(size);
566 /* Now go through the whole screen, repeatedly grabbing n lines */
567 for (y = 0; y < h-n; y += n)
569 unsigned char md[MD_DIGEST_LENGTH];
571 /* Bitblt screen DC to memory DC */
572 BitBlt(hMemDC, 0, 0, w, n, hScrDC, 0, y, SRCCOPY);
574 /* Copy bitmap bits from memory DC to bmbits */
575 GetBitmapBits(hBitmap, size, bmbits);
577 /* Get the MD5 of the bitmap */
580 /* Seed the random generator with the MD5 digest */
581 RAND_seed(md, MD_DIGEST_LENGTH);
587 /* Select old bitmap back into memory DC */
588 hBitmap = SelectObject(hMemDC, hOldBitmap);
591 DeleteObject(hBitmap);