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1 /* crypto/rand/md_rand.c */ | |
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) | |
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 */ | |
58 /* ==================================================================== | |
59 * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved. | |
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 */ | |
111 | |
112 #define OPENSSL_FIPSEVP | |
113 | |
114 #ifdef MD_RAND_DEBUG | |
115 # ifndef NDEBUG | |
116 # define NDEBUG | |
117 # endif | |
118 #endif | |
119 | |
120 #include <assert.h> | |
121 #include <stdio.h> | |
122 #include <string.h> | |
123 | |
124 #include "e_os.h" | |
125 | |
126 #include <openssl/crypto.h> | |
127 #include <openssl/rand.h> | |
128 #include "rand_lcl.h" | |
129 | |
130 #include <openssl/err.h> | |
131 | |
132 #ifdef BN_DEBUG | |
133 # define PREDICT | |
134 #endif | |
135 | |
136 /* #define PREDICT 1 */ | |
137 | |
138 #define STATE_SIZE 1023 | |
139 static int state_num=0,state_index=0; | |
140 static unsigned char state[STATE_SIZE+MD_DIGEST_LENGTH]; | |
141 static unsigned char md[MD_DIGEST_LENGTH]; | |
142 static long md_count[2]={0,0}; | |
143 static double entropy=0; | |
144 static int initialized=0; | |
145 | |
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) */ | |
149 /* access to lockin_thread is synchronized by CRYPTO_LOCK_RAND2 */ | |
150 static CRYPTO_THREADID locking_threadid; /* valid iff crypto_lock_rand is set */ | |
151 | |
152 | |
153 #ifdef PREDICT | |
154 int rand_predictable=0; | |
155 #endif | |
156 | |
157 const char RAND_version[]="RAND" OPENSSL_VERSION_PTEXT; | |
158 | |
159 static void ssleay_rand_cleanup(void); | |
160 static void ssleay_rand_seed(const void *buf, int num); | |
161 static void ssleay_rand_add(const void *buf, int num, double add_entropy); | |
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); | |
164 static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num); | |
165 static int ssleay_rand_status(void); | |
166 | |
167 RAND_METHOD rand_ssleay_meth={ | |
168 ssleay_rand_seed, | |
169 ssleay_rand_nopseudo_bytes, | |
170 ssleay_rand_cleanup, | |
171 ssleay_rand_add, | |
172 ssleay_rand_pseudo_bytes, | |
173 ssleay_rand_status | |
174 }; | |
175 | |
176 RAND_METHOD *RAND_SSLeay(void) | |
177 { | |
178 return(&rand_ssleay_meth); | |
179 } | |
180 | |
181 static void ssleay_rand_cleanup(void) | |
182 { | |
183 OPENSSL_cleanse(state,sizeof(state)); | |
184 state_num=0; | |
185 state_index=0; | |
186 OPENSSL_cleanse(md,MD_DIGEST_LENGTH); | |
187 md_count[0]=0; | |
188 md_count[1]=0; | |
189 entropy=0; | |
190 initialized=0; | |
191 } | |
192 | |
193 static void ssleay_rand_add(const void *buf, int num, double add) | |
194 { | |
195 int i,j,k,st_idx; | |
196 long md_c[2]; | |
197 unsigned char local_md[MD_DIGEST_LENGTH]; | |
198 EVP_MD_CTX m; | |
199 int do_not_lock; | |
200 | |
201 /* | |
202 * (Based on the rand(3) manpage) | |
203 * | |
204 * The input is chopped up into units of 20 bytes (or less for | |
205 * the last block). Each of these blocks is run through the hash | |
206 * function as follows: The data passed to the hash function | |
207 * is the current 'md', the same number of bytes from the 'state' | |
208 * (the location determined by in incremented looping index) as | |
209 * the current 'block', the new key data 'block', and 'count' | |
210 * (which is incremented after each use). | |
211 * The result of this is kept in 'md' and also xored into the | |
212 * 'state' at the same locations that were used as input into the | |
213 * hash function. | |
214 */ | |
215 | |
216 /* check if we already have the lock */ | |
217 if (crypto_lock_rand) | |
218 { | |
219 CRYPTO_THREADID cur; | |
220 CRYPTO_THREADID_current(&cur); | |
221 CRYPTO_r_lock(CRYPTO_LOCK_RAND2); | |
222 do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); | |
223 CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); | |
224 } | |
225 else | |
226 do_not_lock = 0; | |
227 | |
228 if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
229 st_idx=state_index; | |
230 | |
231 /* use our own copies of the counters so that even | |
232 * if a concurrent thread seeds with exactly the | |
233 * same data and uses the same subarray there's _some_ | |
234 * difference */ | |
235 md_c[0] = md_count[0]; | |
236 md_c[1] = md_count[1]; | |
237 | |
238 memcpy(local_md, md, sizeof md); | |
239 | |
240 /* state_index <= state_num <= STATE_SIZE */ | |
241 state_index += num; | |
242 if (state_index >= STATE_SIZE) | |
243 { | |
244 state_index%=STATE_SIZE; | |
245 state_num=STATE_SIZE; | |
246 } | |
247 else if (state_num < STATE_SIZE) | |
248 { | |
249 if (state_index > state_num) | |
250 state_num=state_index; | |
251 } | |
252 /* state_index <= state_num <= STATE_SIZE */ | |
253 | |
254 /* state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE] | |
255 * are what we will use now, but other threads may use them | |
256 * as well */ | |
257 | |
258 md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0); | |
259 | |
260 if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
261 | |
262 EVP_MD_CTX_init(&m); | |
263 for (i=0; i<num; i+=MD_DIGEST_LENGTH) | |
264 { | |
265 j=(num-i); | |
266 j=(j > MD_DIGEST_LENGTH)?MD_DIGEST_LENGTH:j; | |
267 | |
268 MD_Init(&m); | |
269 MD_Update(&m,local_md,MD_DIGEST_LENGTH); | |
270 k=(st_idx+j)-STATE_SIZE; | |
271 if (k > 0) | |
272 { | |
273 MD_Update(&m,&(state[st_idx]),j-k); | |
274 MD_Update(&m,&(state[0]),k); | |
275 } | |
276 else | |
277 MD_Update(&m,&(state[st_idx]),j); | |
278 | |
279 /* DO NOT REMOVE THE FOLLOWING CALL TO MD_Update()! */ | |
280 MD_Update(&m,buf,j); | |
281 /* We know that line may cause programs such as | |
282 purify and valgrind to complain about use of | |
283 uninitialized data. The problem is not, it's | |
284 with the caller. Removing that line will make | |
285 sure you get really bad randomness and thereby | |
286 other problems such as very insecure keys. */ | |
287 | |
288 MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)); | |
289 MD_Final(&m,local_md); | |
290 md_c[1]++; | |
291 | |
292 buf=(const char *)buf + j; | |
293 | |
294 for (k=0; k<j; k++) | |
295 { | |
296 /* Parallel threads may interfere with this, | |
297 * but always each byte of the new state is | |
298 * the XOR of some previous value of its | |
299 * and local_md (itermediate values may be lost). | |
300 * Alway using locking could hurt performance more | |
301 * than necessary given that conflicts occur only | |
302 * when the total seeding is longer than the random | |
303 * state. */ | |
304 state[st_idx++]^=local_md[k]; | |
305 if (st_idx >= STATE_SIZE) | |
306 st_idx=0; | |
307 } | |
308 } | |
309 EVP_MD_CTX_cleanup(&m); | |
310 | |
311 if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
312 /* Don't just copy back local_md into md -- this could mean that | |
313 * other thread's seeding remains without effect (except for | |
314 * the incremented counter). By XORing it we keep at least as | |
315 * much entropy as fits into md. */ | |
316 for (k = 0; k < (int)sizeof(md); k++) | |
317 { | |
318 md[k] ^= local_md[k]; | |
319 } | |
320 if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */ | |
321 entropy += add; | |
322 if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
323 | |
324 #if !defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32) | |
325 assert(md_c[1] == md_count[1]); | |
326 #endif | |
327 } | |
328 | |
329 static void ssleay_rand_seed(const void *buf, int num) | |
330 { | |
331 ssleay_rand_add(buf, num, (double)num); | |
332 } | |
333 | |
334 static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo) | |
335 { | |
336 static volatile int stirred_pool = 0; | |
337 int i,j,k,st_num,st_idx; | |
338 int num_ceil; | |
339 int ok; | |
340 long md_c[2]; | |
341 unsigned char local_md[MD_DIGEST_LENGTH]; | |
342 EVP_MD_CTX m; | |
343 #ifndef GETPID_IS_MEANINGLESS | |
344 pid_t curr_pid = getpid(); | |
345 #endif | |
346 int do_stir_pool = 0; | |
347 | |
348 #ifdef PREDICT | |
349 if (rand_predictable) | |
350 { | |
351 static unsigned char val=0; | |
352 | |
353 for (i=0; i<num; i++) | |
354 buf[i]=val++; | |
355 return(1); | |
356 } | |
357 #endif | |
358 | |
359 if (num <= 0) | |
360 return 1; | |
361 | |
362 EVP_MD_CTX_init(&m); | |
363 /* round upwards to multiple of MD_DIGEST_LENGTH/2 */ | |
364 num_ceil = (1 + (num-1)/(MD_DIGEST_LENGTH/2)) * (MD_DIGEST_LENGTH/2); | |
365 | |
366 /* | |
367 * (Based on the rand(3) manpage:) | |
368 * | |
369 * For each group of 10 bytes (or less), we do the following: | |
370 * | |
371 * Input into the hash function the local 'md' (which is initialized fro
m | |
372 * the global 'md' before any bytes are generated), the bytes that are t
o | |
373 * be overwritten by the random bytes, and bytes from the 'state' | |
374 * (incrementing looping index). From this digest output (which is kept | |
375 * in 'md'), the top (up to) 10 bytes are returned to the caller and the | |
376 * bottom 10 bytes are xored into the 'state'. | |
377 * | |
378 * Finally, after we have finished 'num' random bytes for the | |
379 * caller, 'count' (which is incremented) and the local and global 'md' | |
380 * are fed into the hash function and the results are kept in the | |
381 * global 'md'. | |
382 */ | |
383 | |
384 CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
385 | |
386 /* prevent ssleay_rand_bytes() from trying to obtain the lock again */ | |
387 CRYPTO_w_lock(CRYPTO_LOCK_RAND2); | |
388 CRYPTO_THREADID_current(&locking_threadid); | |
389 CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); | |
390 crypto_lock_rand = 1; | |
391 | |
392 if (!initialized) | |
393 { | |
394 RAND_poll(); | |
395 initialized = 1; | |
396 } | |
397 | |
398 if (!stirred_pool) | |
399 do_stir_pool = 1; | |
400 | |
401 ok = (entropy >= ENTROPY_NEEDED); | |
402 if (!ok) | |
403 { | |
404 /* If the PRNG state is not yet unpredictable, then seeing | |
405 * the PRNG output may help attackers to determine the new | |
406 * state; thus we have to decrease the entropy estimate. | |
407 * Once we've had enough initial seeding we don't bother to | |
408 * adjust the entropy count, though, because we're not ambitious | |
409 * to provide *information-theoretic* randomness. | |
410 * | |
411 * NOTE: This approach fails if the program forks before | |
412 * we have enough entropy. Entropy should be collected | |
413 * in a separate input pool and be transferred to the | |
414 * output pool only when the entropy limit has been reached. | |
415 */ | |
416 entropy -= num; | |
417 if (entropy < 0) | |
418 entropy = 0; | |
419 } | |
420 | |
421 if (do_stir_pool) | |
422 { | |
423 /* In the output function only half of 'md' remains secret, | |
424 * so we better make sure that the required entropy gets | |
425 * 'evenly distributed' through 'state', our randomness pool. | |
426 * The input function (ssleay_rand_add) chains all of 'md', | |
427 * which makes it more suitable for this purpose. | |
428 */ | |
429 | |
430 int n = STATE_SIZE; /* so that the complete pool gets accessed *
/ | |
431 while (n > 0) | |
432 { | |
433 #if MD_DIGEST_LENGTH > 20 | |
434 # error "Please adjust DUMMY_SEED." | |
435 #endif | |
436 #define DUMMY_SEED "...................." /* at least MD_DIGEST_LENGTH */ | |
437 /* Note that the seed does not matter, it's just that | |
438 * ssleay_rand_add expects to have something to hash. */ | |
439 ssleay_rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0); | |
440 n -= MD_DIGEST_LENGTH; | |
441 } | |
442 if (ok) | |
443 stirred_pool = 1; | |
444 } | |
445 | |
446 st_idx=state_index; | |
447 st_num=state_num; | |
448 md_c[0] = md_count[0]; | |
449 md_c[1] = md_count[1]; | |
450 memcpy(local_md, md, sizeof md); | |
451 | |
452 state_index+=num_ceil; | |
453 if (state_index > state_num) | |
454 state_index %= state_num; | |
455 | |
456 /* state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num] | |
457 * are now ours (but other threads may use them too) */ | |
458 | |
459 md_count[0] += 1; | |
460 | |
461 /* before unlocking, we must clear 'crypto_lock_rand' */ | |
462 crypto_lock_rand = 0; | |
463 CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
464 | |
465 while (num > 0) | |
466 { | |
467 /* num_ceil -= MD_DIGEST_LENGTH/2 */ | |
468 j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num; | |
469 num-=j; | |
470 MD_Init(&m); | |
471 #ifndef GETPID_IS_MEANINGLESS | |
472 if (curr_pid) /* just in the first iteration to save time */ | |
473 { | |
474 MD_Update(&m,(unsigned char*)&curr_pid,sizeof curr_pid); | |
475 curr_pid = 0; | |
476 } | |
477 #endif | |
478 MD_Update(&m,local_md,MD_DIGEST_LENGTH); | |
479 MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)); | |
480 | |
481 #ifndef PURIFY /* purify complains */ | |
482 /* The following line uses the supplied buffer as a small | |
483 * source of entropy: since this buffer is often uninitialised | |
484 * it may cause programs such as purify or valgrind to | |
485 * complain. So for those builds it is not used: the removal | |
486 * of such a small source of entropy has negligible impact on | |
487 * security. | |
488 */ | |
489 MD_Update(&m,buf,j); | |
490 #endif | |
491 | |
492 k=(st_idx+MD_DIGEST_LENGTH/2)-st_num; | |
493 if (k > 0) | |
494 { | |
495 MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2-k); | |
496 MD_Update(&m,&(state[0]),k); | |
497 } | |
498 else | |
499 MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2); | |
500 MD_Final(&m,local_md); | |
501 | |
502 for (i=0; i<MD_DIGEST_LENGTH/2; i++) | |
503 { | |
504 state[st_idx++]^=local_md[i]; /* may compete with other
threads */ | |
505 if (st_idx >= st_num) | |
506 st_idx=0; | |
507 if (i < j) | |
508 *(buf++)=local_md[i+MD_DIGEST_LENGTH/2]; | |
509 } | |
510 } | |
511 | |
512 MD_Init(&m); | |
513 MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)); | |
514 MD_Update(&m,local_md,MD_DIGEST_LENGTH); | |
515 CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
516 MD_Update(&m,md,MD_DIGEST_LENGTH); | |
517 MD_Final(&m,md); | |
518 CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
519 | |
520 EVP_MD_CTX_cleanup(&m); | |
521 if (ok) | |
522 return(1); | |
523 else if (pseudo) | |
524 return 0; | |
525 else | |
526 { | |
527 RANDerr(RAND_F_SSLEAY_RAND_BYTES,RAND_R_PRNG_NOT_SEEDED); | |
528 ERR_add_error_data(1, "You need to read the OpenSSL FAQ, " | |
529 "http://www.openssl.org/support/faq.html"); | |
530 return(0); | |
531 } | |
532 } | |
533 | |
534 static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num) | |
535 { | |
536 return ssleay_rand_bytes(buf, num, 0); | |
537 } | |
538 | |
539 /* pseudo-random bytes that are guaranteed to be unique but not | |
540 unpredictable */ | |
541 static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) | |
542 { | |
543 return ssleay_rand_bytes(buf, num, 1); | |
544 } | |
545 | |
546 static int ssleay_rand_status(void) | |
547 { | |
548 CRYPTO_THREADID cur; | |
549 int ret; | |
550 int do_not_lock; | |
551 | |
552 CRYPTO_THREADID_current(&cur); | |
553 /* check if we already have the lock | |
554 * (could happen if a RAND_poll() implementation calls RAND_status()) */ | |
555 if (crypto_lock_rand) | |
556 { | |
557 CRYPTO_r_lock(CRYPTO_LOCK_RAND2); | |
558 do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); | |
559 CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); | |
560 } | |
561 else | |
562 do_not_lock = 0; | |
563 | |
564 if (!do_not_lock) | |
565 { | |
566 CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
567 | |
568 /* prevent ssleay_rand_bytes() from trying to obtain the lock ag
ain */ | |
569 CRYPTO_w_lock(CRYPTO_LOCK_RAND2); | |
570 CRYPTO_THREADID_cpy(&locking_threadid, &cur); | |
571 CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); | |
572 crypto_lock_rand = 1; | |
573 } | |
574 | |
575 if (!initialized) | |
576 { | |
577 RAND_poll(); | |
578 initialized = 1; | |
579 } | |
580 | |
581 ret = entropy >= ENTROPY_NEEDED; | |
582 | |
583 if (!do_not_lock) | |
584 { | |
585 /* before unlocking, we must clear 'crypto_lock_rand' */ | |
586 crypto_lock_rand = 0; | |
587 | |
588 CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
589 } | |
590 | |
591 return ret; | |
592 } | |
OLD | NEW |