1 /* crypto/rand/md_rand.c */
2 /* Copyright (C) 1995-1997 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.]
61 #include <sys/types.h>
65 #if !defined(USE_MD5_RAND) && !defined(USE_SHA1_RAND) && !defined(USE_MDC2_RAND) && !defined(USE_MD2_RAND)
68 #elif !defined(NO_SHA1)
70 #elif !defined(NO_MDC2)
72 #elif !defined(NO_MD2)
75 We need a message digest of some type
79 /* Changed how the state buffer used. I now attempt to 'wrap' such
80 * that I don't run over the same locations the next time go through
81 * the 1023 bytes - many thanks to
82 * Robert J. LeBlanc <rjl@renaissoft.com> for his comments
85 #if defined(USE_MD5_RAND)
87 #define MD_DIGEST_LENGTH MD5_DIGEST_LENGTH
88 #define MD_CTX MD5_CTX
89 #define MD_Init(a) MD5_Init(a)
90 #define MD_Update(a,b,c) MD5_Update(a,b,c)
91 #define MD_Final(a,b) MD5_Final(a,b)
92 #elif defined(USE_SHA1_RAND)
94 #define MD_DIGEST_LENGTH SHA_DIGEST_LENGTH
95 #define MD_CTX SHA_CTX
96 #define MD_Init(a) SHA1_Init(a)
97 #define MD_Update(a,b,c) SHA1_Update(a,b,c)
98 #define MD_Final(a,b) SHA1_Final(a,b)
99 #elif defined(USE_MDC2_RAND)
101 #define MD_DIGEST_LENGTH MDC2_DIGEST_LENGTH
102 #define MD_CTX MDC2_CTX
103 #define MD_Init(a) MDC2_Init(a)
104 #define MD_Update(a,b,c) MDC2_Update(a,b,c)
105 #define MD_Final(a,b) MDC2_Final(a,b)
106 #elif defined(USE_MD2_RAND)
108 #define MD_DIGEST_LENGTH MD2_DIGEST_LENGTH
109 #define MD_CTX MD2_CTX
110 #define MD_Init(a) MD2_Init(a)
111 #define MD_Update(a,b,c) MD2_Update(a,b,c)
112 #define MD_Final(a,b) MD2_Final(a,b)
117 /*#define NORAND 1 */
118 /*#define PREDICT 1 */
120 #define STATE_SIZE 1023
121 static int state_num=0,state_index=0;
122 static unsigned char state[STATE_SIZE];
123 static unsigned char md[MD_DIGEST_LENGTH];
126 char *RAND_version="RAND part of SSLeay 0.8.1b 29-Jun-1998";
130 memset(state,0,STATE_SIZE);
133 memset(md,0,MD_DIGEST_LENGTH);
137 void RAND_seed(buf,num)
141 int i,j,k,st_idx,st_num;
148 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
152 state_index=(state_index+num);
153 if (state_index > STATE_SIZE)
155 state_index%=STATE_SIZE;
156 state_num=STATE_SIZE;
158 else if (state_num < STATE_SIZE)
160 if (state_index > state_num)
161 state_num=state_index;
163 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
165 for (i=0; i<num; i+=MD_DIGEST_LENGTH)
168 j=(j > MD_DIGEST_LENGTH)?MD_DIGEST_LENGTH:j;
171 MD_Update(&m,md,MD_DIGEST_LENGTH);
172 k=(st_idx+j)-STATE_SIZE;
175 MD_Update(&m,&(state[st_idx]),j-k);
176 MD_Update(&m,&(state[0]),k);
179 MD_Update(&m,&(state[st_idx]),j);
188 state[st_idx++]^=md[k];
189 if (st_idx >= STATE_SIZE)
196 memset((char *)&m,0,sizeof(m));
199 void RAND_bytes(buf,num)
203 int i,j,k,st_num,st_idx;
213 static unsigned char val=0;
215 for (i=0; i<num; i++)
221 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
226 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
227 /* put in some default random data, we need more than
229 RAND_seed((unsigned char *)&m,sizeof(m));
232 RAND_seed((unsigned char *)&l,sizeof(l));
234 RAND_seed((unsigned char *)&l,sizeof(l));
237 RAND_seed((unsigned char *)&l,sizeof(l));
241 * Use a random entropy pool device.
242 * Linux 1.3.x and FreeBSD-Current has
243 * this. Use /dev/urandom if you can
244 * as /dev/random will block if it runs out
247 if ((fh = fopen(DEVRANDOM, "r")) != NULL)
249 unsigned char buf[32];
251 fread((unsigned char *)buf,1,32,fh);
252 /* we don't care how many bytes we read,
253 * we will just copy the 'stack' if there is
254 * nothing else :-) */
261 memset(state,0,STATE_SIZE);
262 memset(md,0,MD_DIGEST_LENGTH);
264 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
270 if (state_index > state_num)
271 state_index=(state_index%state_num);
273 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
277 j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num;
280 MD_Update(&m,&(md[MD_DIGEST_LENGTH/2]),MD_DIGEST_LENGTH/2);
282 MD_Update(&m,buf,j); /* purify complains */
287 MD_Update(&m,&(state[st_idx]),j-k);
288 MD_Update(&m,&(state[0]),k);
291 MD_Update(&m,&(state[st_idx]),j);
296 if (st_idx >= st_num)
298 state[st_idx++]^=md[i];
299 *(buf++)=md[i+MD_DIGEST_LENGTH/2];
304 MD_Update(&m,(unsigned char *)&count,sizeof(count)); count++;
305 MD_Update(&m,md,MD_DIGEST_LENGTH);
307 memset(&m,0,sizeof(m));
314 /*****************************************************************************
315 * Initialisation function for the SSL random generator. Takes the contents
316 * of the screen as random seed.
318 * Created 960901 by Gertjan van Oosten, gertjan@West.NL, West Consulting B.V.
321 * <URL:http://www.microsoft.com/kb/developr/win_dk/q97193.htm>;
322 * the original copyright message is:
324 // (C) Copyright Microsoft Corp. 1993. All rights reserved.
326 // You have a royalty-free right to use, modify, reproduce and
327 // distribute the Sample Files (and/or any modified version) in
328 // any way you find useful, provided that you agree that
329 // Microsoft has no warranty obligations or liability for any
330 // Sample Application Files which are modified.
333 * I have modified the loading of bytes via RAND_seed() mechanism since
334 * the origional would have been very very CPU intensive since RAND_seed()
335 * does an MD5 per 16 bytes of input. The cost to digest 16 bytes is the same
336 * as that to digest 56 bytes. So under the old system, a screen of
337 * 1024*768*256 would have been CPU cost of approximatly 49,000 56 byte MD5
338 * digests or digesting 2.7 mbytes. What I have put in place would
339 * be 48 16k MD5 digests, or efectivly 48*16+48 MD5 bytes or 816 kbytes
340 * or about 3.5 times as much.
343 void RAND_screen(void)
345 HDC hScrDC; /* screen DC */
346 HDC hMemDC; /* memory DC */
347 HBITMAP hBitmap; /* handle for our bitmap */
348 HBITMAP hOldBitmap; /* handle for previous bitmap */
349 BITMAP bm; /* bitmap properties */
350 unsigned int size; /* size of bitmap */
351 char *bmbits; /* contents of bitmap */
352 int w; /* screen width */
353 int h; /* screen height */
354 int y; /* y-coordinate of screen lines to grab */
355 int n = 16; /* number of screen lines to grab at a time */
357 /* Create a screen DC and a memory DC compatible to screen DC */
358 hScrDC = CreateDC("DISPLAY", NULL, NULL, NULL);
359 hMemDC = CreateCompatibleDC(hScrDC);
361 /* Get screen resolution */
362 w = GetDeviceCaps(hScrDC, HORZRES);
363 h = GetDeviceCaps(hScrDC, VERTRES);
365 /* Create a bitmap compatible with the screen DC */
366 hBitmap = CreateCompatibleBitmap(hScrDC, w, n);
368 /* Select new bitmap into memory DC */
369 hOldBitmap = SelectObject(hMemDC, hBitmap);
371 /* Get bitmap properties */
372 GetObject(hBitmap, sizeof(BITMAP), (LPSTR)&bm);
373 size = (unsigned int)bm.bmWidthBytes * bm.bmHeight * bm.bmPlanes;
375 bmbits = Malloc(size);
377 /* Now go through the whole screen, repeatedly grabbing n lines */
378 for (y = 0; y < h-n; y += n)
380 unsigned char md[MD_DIGEST_LENGTH];
382 /* Bitblt screen DC to memory DC */
383 BitBlt(hMemDC, 0, 0, w, n, hScrDC, 0, y, SRCCOPY);
385 /* Copy bitmap bits from memory DC to bmbits */
386 GetBitmapBits(hBitmap, size, bmbits);
388 /* Get the MD5 of the bitmap */
391 /* Seed the random generator with the MD5 digest */
392 RAND_seed(md, MD_DIGEST_LENGTH);
398 /* Select old bitmap back into memory DC */
399 hBitmap = SelectObject(hMemDC, hOldBitmap);
402 DeleteObject(hBitmap);