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a6aa71ff | 1 | /* crypto/rand/md_rand.c */ |
58964a49 | 2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
d02b48c6 RE |
3 | * All rights reserved. |
4 | * | |
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. | |
8 | * | |
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). | |
15 | * | |
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. | |
22 | * | |
23 | * Redistribution and use in source and binary forms, with or without | |
24 | * modification, are permitted provided that the following conditions | |
25 | * are met: | |
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)" | |
40 | * | |
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 | |
51 | * SUCH DAMAGE. | |
52 | * | |
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.] | |
57 | */ | |
863fe2ec | 58 | /* ==================================================================== |
f9b0f47c | 59 | * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved. |
863fe2ec BM |
60 | * |
61 | * Redistribution and use in source and binary forms, with or without | |
62 | * modification, are permitted provided that the following conditions | |
63 | * are met: | |
64 | * | |
65 | * 1. Redistributions of source code must retain the above copyright | |
66 | * notice, this list of conditions and the following disclaimer. | |
67 | * | |
68 | * 2. Redistributions in binary form must reproduce the above copyright | |
69 | * notice, this list of conditions and the following disclaimer in | |
70 | * the documentation and/or other materials provided with the | |
71 | * distribution. | |
72 | * | |
73 | * 3. All advertising materials mentioning features or use of this | |
74 | * software must display the following acknowledgment: | |
75 | * "This product includes software developed by the OpenSSL Project | |
76 | * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" | |
77 | * | |
78 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to | |
79 | * endorse or promote products derived from this software without | |
80 | * prior written permission. For written permission, please contact | |
81 | * openssl-core@openssl.org. | |
82 | * | |
83 | * 5. Products derived from this software may not be called "OpenSSL" | |
84 | * nor may "OpenSSL" appear in their names without prior written | |
85 | * permission of the OpenSSL Project. | |
86 | * | |
87 | * 6. Redistributions of any form whatsoever must retain the following | |
88 | * acknowledgment: | |
89 | * "This product includes software developed by the OpenSSL Project | |
90 | * for use in the OpenSSL Toolkit (http://www.openssl.org/)" | |
91 | * | |
92 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY | |
93 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
94 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
95 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR | |
96 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
97 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
98 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
99 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
100 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
101 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
102 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | |
103 | * OF THE POSSIBILITY OF SUCH DAMAGE. | |
104 | * ==================================================================== | |
105 | * | |
106 | * This product includes cryptographic software written by Eric Young | |
107 | * (eay@cryptsoft.com). This product includes software written by Tim | |
108 | * Hudson (tjh@cryptsoft.com). | |
109 | * | |
110 | */ | |
d02b48c6 | 111 | |
7c8ced94 | 112 | #define OPENSSL_FIPSAPI |
4ead4e52 | 113 | |
2ace287d | 114 | #ifdef MD_RAND_DEBUG |
c1e744b9 BM |
115 | # ifndef NDEBUG |
116 | # define NDEBUG | |
117 | # endif | |
118 | #endif | |
119 | ||
120 | #include <assert.h> | |
d02b48c6 | 121 | #include <stdio.h> |
a224de3f | 122 | #include <string.h> |
17e3dd1c | 123 | |
41d2a336 | 124 | #include "e_os.h" |
17e3dd1c | 125 | |
8ad7635e UM |
126 | #include <openssl/rand.h> |
127 | #include "rand_lcl.h" | |
128 | ||
ec577822 | 129 | #include <openssl/crypto.h> |
eb952088 | 130 | #include <openssl/err.h> |
d02b48c6 | 131 | |
e64dceab UM |
132 | #ifdef BN_DEBUG |
133 | # define PREDICT | |
134 | #endif | |
135 | ||
dfeab068 | 136 | /* #define PREDICT 1 */ |
d02b48c6 RE |
137 | |
138 | #define STATE_SIZE 1023 | |
139 | static int state_num=0,state_index=0; | |
58964a49 | 140 | static unsigned char state[STATE_SIZE+MD_DIGEST_LENGTH]; |
d02b48c6 | 141 | static unsigned char md[MD_DIGEST_LENGTH]; |
dfeab068 | 142 | static long md_count[2]={0,0}; |
853f757e | 143 | static double entropy=0; |
4ec2d4d2 | 144 | static int initialized=0; |
d02b48c6 | 145 | |
6e6d04e2 BM |
146 | static unsigned int crypto_lock_rand = 0; /* may be set only when a thread |
147 | * holds CRYPTO_LOCK_RAND | |
148 | * (to prevent double locking) */ | |
daba492c | 149 | /* access to lockin_thread is synchronized by CRYPTO_LOCK_RAND2 */ |
4c329696 | 150 | static CRYPTO_THREADID locking_threadid; /* valid iff crypto_lock_rand is set */ |
6e6d04e2 | 151 | |
a4125514 | 152 | |
e64dceab UM |
153 | #ifdef PREDICT |
154 | int rand_predictable=0; | |
155 | #endif | |
156 | ||
560b79cb | 157 | const char RAND_version[]="RAND" OPENSSL_VERSION_PTEXT; |
d02b48c6 | 158 | |
dfeab068 | 159 | static void ssleay_rand_cleanup(void); |
b6dcdbfc DSH |
160 | static int ssleay_rand_seed(const void *buf, int num); |
161 | static int ssleay_rand_add(const void *buf, int num, double add_entropy); | |
4ead4e52 DSH |
162 | static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo); |
163 | static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num); | |
6343829a | 164 | static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num); |
5eb8ca4d | 165 | static int ssleay_rand_status(void); |
dfeab068 | 166 | |
651d0aff | 167 | RAND_METHOD rand_ssleay_meth={ |
dfeab068 | 168 | ssleay_rand_seed, |
4ead4e52 | 169 | ssleay_rand_nopseudo_bytes, |
dfeab068 | 170 | ssleay_rand_cleanup, |
eb952088 | 171 | ssleay_rand_add, |
373b575f | 172 | ssleay_rand_pseudo_bytes, |
5eb8ca4d | 173 | ssleay_rand_status |
dfeab068 RE |
174 | }; |
175 | ||
6b691a5c | 176 | RAND_METHOD *RAND_SSLeay(void) |
dfeab068 | 177 | { |
651d0aff | 178 | return(&rand_ssleay_meth); |
dfeab068 RE |
179 | } |
180 | ||
6b691a5c | 181 | static void ssleay_rand_cleanup(void) |
d02b48c6 | 182 | { |
4579924b | 183 | OPENSSL_cleanse(state,sizeof(state)); |
d02b48c6 RE |
184 | state_num=0; |
185 | state_index=0; | |
4579924b | 186 | OPENSSL_cleanse(md,MD_DIGEST_LENGTH); |
dfeab068 RE |
187 | md_count[0]=0; |
188 | md_count[1]=0; | |
eb952088 | 189 | entropy=0; |
d3093944 | 190 | initialized=0; |
d02b48c6 RE |
191 | } |
192 | ||
b6dcdbfc | 193 | static int ssleay_rand_add(const void *buf, int num, double add) |
d02b48c6 | 194 | { |
6343829a | 195 | int i,j,k,st_idx; |
c1e744b9 BM |
196 | long md_c[2]; |
197 | unsigned char local_md[MD_DIGEST_LENGTH]; | |
dbad1690 | 198 | EVP_MD_CTX m; |
6e6d04e2 | 199 | int do_not_lock; |
b6dcdbfc | 200 | int rv = 0; |
d02b48c6 | 201 | |
c1e744b9 | 202 | /* |
60b52453 | 203 | * (Based on the rand(3) manpage) |
c1e744b9 | 204 | * |
c88a900f | 205 | * The input is chopped up into units of 20 bytes (or less for |
60b52453 | 206 | * the last block). Each of these blocks is run through the hash |
0b5cfe32 | 207 | * function as follows: The data passed to the hash function |
c1e744b9 BM |
208 | * is the current 'md', the same number of bytes from the 'state' |
209 | * (the location determined by in incremented looping index) as | |
210 | * the current 'block', the new key data 'block', and 'count' | |
211 | * (which is incremented after each use). | |
212 | * The result of this is kept in 'md' and also xored into the | |
60b52453 UM |
213 | * 'state' at the same locations that were used as input into the |
214 | * hash function. | |
c1e744b9 BM |
215 | */ |
216 | ||
b6dcdbfc | 217 | EVP_MD_CTX_init(&m); |
6e6d04e2 | 218 | /* check if we already have the lock */ |
daba492c BM |
219 | if (crypto_lock_rand) |
220 | { | |
4c329696 GT |
221 | CRYPTO_THREADID cur; |
222 | CRYPTO_THREADID_current(&cur); | |
daba492c | 223 | CRYPTO_r_lock(CRYPTO_LOCK_RAND2); |
4c329696 | 224 | do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); |
daba492c BM |
225 | CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); |
226 | } | |
227 | else | |
228 | do_not_lock = 0; | |
6e6d04e2 BM |
229 | |
230 | if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
d02b48c6 | 231 | st_idx=state_index; |
d02b48c6 | 232 | |
c1e744b9 BM |
233 | /* use our own copies of the counters so that even |
234 | * if a concurrent thread seeds with exactly the | |
235 | * same data and uses the same subarray there's _some_ | |
236 | * difference */ | |
237 | md_c[0] = md_count[0]; | |
238 | md_c[1] = md_count[1]; | |
239 | ||
240 | memcpy(local_md, md, sizeof md); | |
241 | ||
242 | /* state_index <= state_num <= STATE_SIZE */ | |
243 | state_index += num; | |
58964a49 | 244 | if (state_index >= STATE_SIZE) |
d02b48c6 RE |
245 | { |
246 | state_index%=STATE_SIZE; | |
247 | state_num=STATE_SIZE; | |
248 | } | |
249 | else if (state_num < STATE_SIZE) | |
250 | { | |
251 | if (state_index > state_num) | |
252 | state_num=state_index; | |
253 | } | |
c1e744b9 BM |
254 | /* state_index <= state_num <= STATE_SIZE */ |
255 | ||
256 | /* state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE] | |
257 | * are what we will use now, but other threads may use them | |
258 | * as well */ | |
259 | ||
260 | md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0); | |
261 | ||
6e6d04e2 | 262 | if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND); |
d02b48c6 RE |
263 | |
264 | for (i=0; i<num; i+=MD_DIGEST_LENGTH) | |
265 | { | |
266 | j=(num-i); | |
267 | j=(j > MD_DIGEST_LENGTH)?MD_DIGEST_LENGTH:j; | |
268 | ||
b6dcdbfc DSH |
269 | if (!MD_Init(&m)) |
270 | goto err; | |
271 | if (!MD_Update(&m,local_md,MD_DIGEST_LENGTH)) | |
272 | goto err; | |
d02b48c6 RE |
273 | k=(st_idx+j)-STATE_SIZE; |
274 | if (k > 0) | |
275 | { | |
b6dcdbfc DSH |
276 | if (!MD_Update(&m,&(state[st_idx]),j-k)) |
277 | goto err; | |
278 | if (!MD_Update(&m,&(state[0]),k)) | |
279 | goto err; | |
d02b48c6 RE |
280 | } |
281 | else | |
b6dcdbfc DSH |
282 | if (!MD_Update(&m,&(state[st_idx]),j)) |
283 | goto err; | |
792bbc23 RL |
284 | |
285 | /* DO NOT REMOVE THE FOLLOWING CALL TO MD_Update()! */ | |
b6dcdbfc DSH |
286 | if (!MD_Update(&m,buf,j)) |
287 | goto err; | |
792bbc23 RL |
288 | /* We know that line may cause programs such as |
289 | purify and valgrind to complain about use of | |
290 | uninitialized data. The problem is not, it's | |
291 | with the caller. Removing that line will make | |
292 | sure you get really bad randomness and thereby | |
293 | other problems such as very insecure keys. */ | |
294 | ||
b6dcdbfc DSH |
295 | if (!MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c))) |
296 | goto err; | |
297 | if (!MD_Final(&m,local_md)) | |
298 | goto err; | |
c1e744b9 | 299 | md_c[1]++; |
d02b48c6 | 300 | |
e778802f | 301 | buf=(const char *)buf + j; |
d02b48c6 RE |
302 | |
303 | for (k=0; k<j; k++) | |
304 | { | |
c1e744b9 BM |
305 | /* Parallel threads may interfere with this, |
306 | * but always each byte of the new state is | |
307 | * the XOR of some previous value of its | |
308 | * and local_md (itermediate values may be lost). | |
309 | * Alway using locking could hurt performance more | |
310 | * than necessary given that conflicts occur only | |
311 | * when the total seeding is longer than the random | |
312 | * state. */ | |
313 | state[st_idx++]^=local_md[k]; | |
d02b48c6 | 314 | if (st_idx >= STATE_SIZE) |
d02b48c6 | 315 | st_idx=0; |
d02b48c6 RE |
316 | } |
317 | } | |
c1e744b9 | 318 | |
6e6d04e2 | 319 | if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND); |
c1e744b9 BM |
320 | /* Don't just copy back local_md into md -- this could mean that |
321 | * other thread's seeding remains without effect (except for | |
322 | * the incremented counter). By XORing it we keep at least as | |
323 | * much entropy as fits into md. */ | |
6343829a | 324 | for (k = 0; k < (int)sizeof(md); k++) |
c1e744b9 BM |
325 | { |
326 | md[k] ^= local_md[k]; | |
327 | } | |
c6709c6b BM |
328 | if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */ |
329 | entropy += add; | |
6e6d04e2 | 330 | if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND); |
c1e744b9 | 331 | |
bc36ee62 | 332 | #if !defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32) |
c1e744b9 BM |
333 | assert(md_c[1] == md_count[1]); |
334 | #endif | |
b6dcdbfc DSH |
335 | rv = 1; |
336 | err: | |
337 | EVP_MD_CTX_cleanup(&m); | |
338 | return rv; | |
eb952088 UM |
339 | } |
340 | ||
b6dcdbfc | 341 | static int ssleay_rand_seed(const void *buf, int num) |
eb952088 | 342 | { |
b6dcdbfc | 343 | return ssleay_rand_add(buf, num, (double)num); |
d02b48c6 RE |
344 | } |
345 | ||
4ead4e52 | 346 | static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo) |
d02b48c6 | 347 | { |
361ee973 | 348 | static volatile int stirred_pool = 0; |
6343829a | 349 | int i,j,k,st_num,st_idx; |
e9ad0d2c | 350 | int num_ceil; |
eb952088 | 351 | int ok; |
c1e744b9 BM |
352 | long md_c[2]; |
353 | unsigned char local_md[MD_DIGEST_LENGTH]; | |
dbad1690 | 354 | EVP_MD_CTX m; |
9a1e34e5 | 355 | #ifndef GETPID_IS_MEANINGLESS |
62ac2938 | 356 | pid_t curr_pid = getpid(); |
c1e744b9 | 357 | #endif |
361ee973 | 358 | int do_stir_pool = 0; |
d02b48c6 RE |
359 | |
360 | #ifdef PREDICT | |
e64dceab UM |
361 | if (rand_predictable) |
362 | { | |
363 | static unsigned char val=0; | |
d02b48c6 | 364 | |
e64dceab UM |
365 | for (i=0; i<num; i++) |
366 | buf[i]=val++; | |
367 | return(1); | |
368 | } | |
d02b48c6 RE |
369 | #endif |
370 | ||
e9ad0d2c BM |
371 | if (num <= 0) |
372 | return 1; | |
dbad1690 BL |
373 | |
374 | EVP_MD_CTX_init(&m); | |
e9ad0d2c BM |
375 | /* round upwards to multiple of MD_DIGEST_LENGTH/2 */ |
376 | num_ceil = (1 + (num-1)/(MD_DIGEST_LENGTH/2)) * (MD_DIGEST_LENGTH/2); | |
377 | ||
c1e744b9 | 378 | /* |
2c8aeddc | 379 | * (Based on the rand(3) manpage:) |
c1e744b9 | 380 | * |
c88a900f | 381 | * For each group of 10 bytes (or less), we do the following: |
c1e744b9 | 382 | * |
e9ad0d2c BM |
383 | * Input into the hash function the local 'md' (which is initialized from |
384 | * the global 'md' before any bytes are generated), the bytes that are to | |
385 | * be overwritten by the random bytes, and bytes from the 'state' | |
386 | * (incrementing looping index). From this digest output (which is kept | |
387 | * in 'md'), the top (up to) 10 bytes are returned to the caller and the | |
388 | * bottom 10 bytes are xored into the 'state'. | |
389 | * | |
c1e744b9 | 390 | * Finally, after we have finished 'num' random bytes for the |
2c8aeddc BM |
391 | * caller, 'count' (which is incremented) and the local and global 'md' |
392 | * are fed into the hash function and the results are kept in the | |
393 | * global 'md'. | |
c1e744b9 BM |
394 | */ |
395 | ||
8ad7635e | 396 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); |
d02b48c6 | 397 | |
6e6d04e2 | 398 | /* prevent ssleay_rand_bytes() from trying to obtain the lock again */ |
daba492c | 399 | CRYPTO_w_lock(CRYPTO_LOCK_RAND2); |
4c329696 | 400 | CRYPTO_THREADID_current(&locking_threadid); |
daba492c | 401 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); |
badb910f | 402 | crypto_lock_rand = 1; |
6e6d04e2 BM |
403 | |
404 | if (!initialized) | |
405 | { | |
406 | RAND_poll(); | |
407 | initialized = 1; | |
408 | } | |
409 | ||
361ee973 BM |
410 | if (!stirred_pool) |
411 | do_stir_pool = 1; | |
412 | ||
eb952088 | 413 | ok = (entropy >= ENTROPY_NEEDED); |
c6709c6b BM |
414 | if (!ok) |
415 | { | |
416 | /* If the PRNG state is not yet unpredictable, then seeing | |
417 | * the PRNG output may help attackers to determine the new | |
418 | * state; thus we have to decrease the entropy estimate. | |
419 | * Once we've had enough initial seeding we don't bother to | |
420 | * adjust the entropy count, though, because we're not ambitious | |
421 | * to provide *information-theoretic* randomness. | |
361ee973 BM |
422 | * |
423 | * NOTE: This approach fails if the program forks before | |
424 | * we have enough entropy. Entropy should be collected | |
425 | * in a separate input pool and be transferred to the | |
426 | * output pool only when the entropy limit has been reached. | |
c6709c6b BM |
427 | */ |
428 | entropy -= num; | |
429 | if (entropy < 0) | |
430 | entropy = 0; | |
431 | } | |
eb952088 | 432 | |
361ee973 BM |
433 | if (do_stir_pool) |
434 | { | |
e9ad0d2c BM |
435 | /* In the output function only half of 'md' remains secret, |
436 | * so we better make sure that the required entropy gets | |
437 | * 'evenly distributed' through 'state', our randomness pool. | |
438 | * The input function (ssleay_rand_add) chains all of 'md', | |
439 | * which makes it more suitable for this purpose. | |
361ee973 BM |
440 | */ |
441 | ||
442 | int n = STATE_SIZE; /* so that the complete pool gets accessed */ | |
443 | while (n > 0) | |
444 | { | |
445 | #if MD_DIGEST_LENGTH > 20 | |
446 | # error "Please adjust DUMMY_SEED." | |
447 | #endif | |
448 | #define DUMMY_SEED "...................." /* at least MD_DIGEST_LENGTH */ | |
449 | /* Note that the seed does not matter, it's just that | |
450 | * ssleay_rand_add expects to have something to hash. */ | |
451 | ssleay_rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0); | |
452 | n -= MD_DIGEST_LENGTH; | |
453 | } | |
454 | if (ok) | |
455 | stirred_pool = 1; | |
456 | } | |
457 | ||
d02b48c6 RE |
458 | st_idx=state_index; |
459 | st_num=state_num; | |
c1e744b9 BM |
460 | md_c[0] = md_count[0]; |
461 | md_c[1] = md_count[1]; | |
462 | memcpy(local_md, md, sizeof md); | |
463 | ||
e9ad0d2c | 464 | state_index+=num_ceil; |
d02b48c6 | 465 | if (state_index > state_num) |
c1e744b9 BM |
466 | state_index %= state_num; |
467 | ||
e9ad0d2c | 468 | /* state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num] |
c1e744b9 | 469 | * are now ours (but other threads may use them too) */ |
d02b48c6 | 470 | |
c1e744b9 | 471 | md_count[0] += 1; |
a4125514 | 472 | |
6e6d04e2 BM |
473 | /* before unlocking, we must clear 'crypto_lock_rand' */ |
474 | crypto_lock_rand = 0; | |
d02b48c6 RE |
475 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); |
476 | ||
477 | while (num > 0) | |
478 | { | |
e9ad0d2c | 479 | /* num_ceil -= MD_DIGEST_LENGTH/2 */ |
d02b48c6 RE |
480 | j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num; |
481 | num-=j; | |
b6dcdbfc DSH |
482 | if (!MD_Init(&m)) |
483 | goto err; | |
9a1e34e5 | 484 | #ifndef GETPID_IS_MEANINGLESS |
62ac2938 BM |
485 | if (curr_pid) /* just in the first iteration to save time */ |
486 | { | |
b6dcdbfc DSH |
487 | if (!MD_Update(&m,(unsigned char*)&curr_pid,sizeof curr_pid)) |
488 | goto err; | |
62ac2938 BM |
489 | curr_pid = 0; |
490 | } | |
491 | #endif | |
b6dcdbfc DSH |
492 | if (!MD_Update(&m,local_md,MD_DIGEST_LENGTH)) |
493 | goto err; | |
494 | if (!MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c))) | |
495 | goto err; | |
792bbc23 RL |
496 | |
497 | #ifndef PURIFY /* purify complains */ | |
a7c64928 DSH |
498 | /* The following line uses the supplied buffer as a small |
499 | * source of entropy: since this buffer is often uninitialised | |
500 | * it may cause programs such as purify or valgrind to | |
501 | * complain. So for those builds it is not used: the removal | |
502 | * of such a small source of entropy has negligible impact on | |
503 | * security. | |
504 | */ | |
b6dcdbfc DSH |
505 | if (!MD_Update(&m,buf,j)) |
506 | goto err; | |
d02b48c6 | 507 | #endif |
792bbc23 | 508 | |
e9ad0d2c | 509 | k=(st_idx+MD_DIGEST_LENGTH/2)-st_num; |
d02b48c6 RE |
510 | if (k > 0) |
511 | { | |
b6dcdbfc DSH |
512 | if (!MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2-k)) |
513 | goto err; | |
514 | if (!MD_Update(&m,&(state[0]),k)) | |
515 | goto err; | |
d02b48c6 RE |
516 | } |
517 | else | |
b6dcdbfc DSH |
518 | if (!MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2)) |
519 | goto err; | |
520 | if (!MD_Final(&m,local_md)) | |
521 | goto err; | |
d02b48c6 | 522 | |
e9ad0d2c | 523 | for (i=0; i<MD_DIGEST_LENGTH/2; i++) |
d02b48c6 | 524 | { |
c1e744b9 | 525 | state[st_idx++]^=local_md[i]; /* may compete with other threads */ |
d02b48c6 RE |
526 | if (st_idx >= st_num) |
527 | st_idx=0; | |
e9ad0d2c BM |
528 | if (i < j) |
529 | *(buf++)=local_md[i+MD_DIGEST_LENGTH/2]; | |
d02b48c6 RE |
530 | } |
531 | } | |
532 | ||
b6dcdbfc DSH |
533 | if (!MD_Init(&m) |
534 | || !MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)) | |
535 | || !MD_Update(&m,local_md,MD_DIGEST_LENGTH)) | |
536 | goto err; | |
c1e744b9 | 537 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); |
b6dcdbfc DSH |
538 | if (!MD_Update(&m,md,MD_DIGEST_LENGTH) || !MD_Final(&m,md)) |
539 | { | |
540 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
541 | goto err; | |
542 | } | |
c1e744b9 BM |
543 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); |
544 | ||
dbad1690 | 545 | EVP_MD_CTX_cleanup(&m); |
eb952088 UM |
546 | if (ok) |
547 | return(1); | |
4ead4e52 DSH |
548 | else if (pseudo) |
549 | return 0; | |
550 | else | |
eb952088 UM |
551 | { |
552 | RANDerr(RAND_F_SSLEAY_RAND_BYTES,RAND_R_PRNG_NOT_SEEDED); | |
3b3bc455 RL |
553 | ERR_add_error_data(1, "You need to read the OpenSSL FAQ, " |
554 | "http://www.openssl.org/support/faq.html"); | |
eb952088 UM |
555 | return(0); |
556 | } | |
b6dcdbfc DSH |
557 | err: |
558 | EVP_MD_CTX_cleanup(&m); | |
559 | RANDerr(RAND_F_SSLEAY_RAND_BYTES,ERR_R_EVP_LIB); | |
560 | return 0; | |
561 | ||
d02b48c6 RE |
562 | } |
563 | ||
4ead4e52 DSH |
564 | static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num) |
565 | { | |
566 | return ssleay_rand_bytes(buf, num, 0); | |
567 | } | |
568 | ||
373b575f UM |
569 | /* pseudo-random bytes that are guaranteed to be unique but not |
570 | unpredictable */ | |
6343829a | 571 | static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) |
373b575f | 572 | { |
4ead4e52 | 573 | return ssleay_rand_bytes(buf, num, 1); |
373b575f UM |
574 | } |
575 | ||
5eb8ca4d | 576 | static int ssleay_rand_status(void) |
4ec2d4d2 | 577 | { |
4c329696 | 578 | CRYPTO_THREADID cur; |
b841e0ac | 579 | int ret; |
6e6d04e2 | 580 | int do_not_lock; |
b841e0ac | 581 | |
4c329696 | 582 | CRYPTO_THREADID_current(&cur); |
6e6d04e2 BM |
583 | /* check if we already have the lock |
584 | * (could happen if a RAND_poll() implementation calls RAND_status()) */ | |
daba492c BM |
585 | if (crypto_lock_rand) |
586 | { | |
587 | CRYPTO_r_lock(CRYPTO_LOCK_RAND2); | |
4c329696 | 588 | do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); |
daba492c BM |
589 | CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); |
590 | } | |
591 | else | |
592 | do_not_lock = 0; | |
6e6d04e2 BM |
593 | |
594 | if (!do_not_lock) | |
595 | { | |
596 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
597 | ||
598 | /* prevent ssleay_rand_bytes() from trying to obtain the lock again */ | |
daba492c | 599 | CRYPTO_w_lock(CRYPTO_LOCK_RAND2); |
4c329696 | 600 | CRYPTO_THREADID_cpy(&locking_threadid, &cur); |
daba492c | 601 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); |
badb910f | 602 | crypto_lock_rand = 1; |
6e6d04e2 BM |
603 | } |
604 | ||
4ec2d4d2 | 605 | if (!initialized) |
6e6d04e2 | 606 | { |
8ad7635e | 607 | RAND_poll(); |
6e6d04e2 BM |
608 | initialized = 1; |
609 | } | |
7ae634de | 610 | |
8ad7635e | 611 | ret = entropy >= ENTROPY_NEEDED; |
7ae634de | 612 | |
6e6d04e2 BM |
613 | if (!do_not_lock) |
614 | { | |
615 | /* before unlocking, we must clear 'crypto_lock_rand' */ | |
616 | crypto_lock_rand = 0; | |
6e6d04e2 BM |
617 | |
618 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
619 | } | |
620 | ||
b841e0ac | 621 | return ret; |
4ec2d4d2 | 622 | } |