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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. | |
0f113f3e | 8 | * |
d02b48c6 RE |
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). | |
0f113f3e | 15 | * |
d02b48c6 RE |
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. | |
0f113f3e | 22 | * |
d02b48c6 RE |
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 :-). | |
0f113f3e | 37 | * 4. If you include any Windows specific code (or a derivative thereof) from |
d02b48c6 RE |
38 | * the apps directory (application code) you must include an acknowledgement: |
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
0f113f3e | 40 | * |
d02b48c6 RE |
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. | |
0f113f3e | 52 | * |
d02b48c6 RE |
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 | |
0f113f3e | 66 | * notice, this list of conditions and the following disclaimer. |
863fe2ec BM |
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 | |
2ace287d | 112 | #ifdef MD_RAND_DEBUG |
c1e744b9 | 113 | # ifndef NDEBUG |
0f113f3e | 114 | # define NDEBUG |
c1e744b9 BM |
115 | # endif |
116 | #endif | |
117 | ||
118 | #include <assert.h> | |
d02b48c6 | 119 | #include <stdio.h> |
a224de3f | 120 | #include <string.h> |
17e3dd1c | 121 | |
41d2a336 | 122 | #include "e_os.h" |
17e3dd1c | 123 | |
68b00c23 | 124 | #if !(defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_DSPBIOS)) |
c051e521 DSH |
125 | # include <sys/time.h> |
126 | #endif | |
127 | #if defined(OPENSSL_SYS_VXWORKS) | |
128 | # include <time.h> | |
129 | #endif | |
130 | ||
d749e108 | 131 | #include <openssl/crypto.h> |
8ad7635e UM |
132 | #include <openssl/rand.h> |
133 | #include "rand_lcl.h" | |
134 | ||
eb952088 | 135 | #include <openssl/err.h> |
d02b48c6 | 136 | |
aa87945f | 137 | #ifdef OPENSSL_FIPS |
0f113f3e | 138 | # include <openssl/fips.h> |
aa87945f DSH |
139 | #endif |
140 | ||
e64dceab UM |
141 | #ifdef BN_DEBUG |
142 | # define PREDICT | |
143 | #endif | |
144 | ||
0f113f3e | 145 | /* #define PREDICT 1 */ |
d02b48c6 | 146 | |
0f113f3e MC |
147 | #define STATE_SIZE 1023 |
148 | static int state_num = 0, state_index = 0; | |
149 | static unsigned char state[STATE_SIZE + MD_DIGEST_LENGTH]; | |
d02b48c6 | 150 | static unsigned char md[MD_DIGEST_LENGTH]; |
0f113f3e MC |
151 | static long md_count[2] = { 0, 0 }; |
152 | ||
153 | static double entropy = 0; | |
154 | static int initialized = 0; | |
d02b48c6 | 155 | |
6e6d04e2 | 156 | static unsigned int crypto_lock_rand = 0; /* may be set only when a thread |
0f113f3e MC |
157 | * holds CRYPTO_LOCK_RAND (to |
158 | * prevent double locking) */ | |
daba492c | 159 | /* access to lockin_thread is synchronized by CRYPTO_LOCK_RAND2 */ |
68d39f3c MC |
160 | /* valid iff crypto_lock_rand is set */ |
161 | static CRYPTO_THREADID locking_threadid; | |
6e6d04e2 | 162 | |
e64dceab | 163 | #ifdef PREDICT |
0f113f3e | 164 | int rand_predictable = 0; |
e64dceab UM |
165 | #endif |
166 | ||
ef643cc7 DSH |
167 | static void rand_hw_seed(EVP_MD_CTX *ctx); |
168 | ||
b0700d2c RS |
169 | static void rand_cleanup(void); |
170 | static int rand_seed(const void *buf, int num); | |
171 | static int rand_add(const void *buf, int num, double add_entropy); | |
172 | static int rand_bytes(unsigned char *buf, int num, int pseudo); | |
173 | static int rand_nopseudo_bytes(unsigned char *buf, int num); | |
302d38e3 | 174 | #ifndef OPENSSL_NO_DEPRECATED |
b0700d2c | 175 | static int rand_pseudo_bytes(unsigned char *buf, int num); |
302d38e3 | 176 | #endif |
b0700d2c | 177 | static int rand_status(void); |
dfeab068 | 178 | |
b0700d2c RS |
179 | static RAND_METHOD rand_meth = { |
180 | rand_seed, | |
181 | rand_nopseudo_bytes, | |
182 | rand_cleanup, | |
183 | rand_add, | |
302d38e3 | 184 | #ifndef OPENSSL_NO_DEPRECATED |
b0700d2c | 185 | rand_pseudo_bytes, |
302d38e3 MC |
186 | #else |
187 | NULL, | |
188 | #endif | |
b0700d2c | 189 | rand_status |
0f113f3e | 190 | }; |
dfeab068 | 191 | |
b0700d2c | 192 | RAND_METHOD *RAND_OpenSSL(void) |
0f113f3e | 193 | { |
b0700d2c | 194 | return (&rand_meth); |
0f113f3e | 195 | } |
dfeab068 | 196 | |
b0700d2c | 197 | static void rand_cleanup(void) |
0f113f3e MC |
198 | { |
199 | OPENSSL_cleanse(state, sizeof(state)); | |
200 | state_num = 0; | |
201 | state_index = 0; | |
202 | OPENSSL_cleanse(md, MD_DIGEST_LENGTH); | |
203 | md_count[0] = 0; | |
204 | md_count[1] = 0; | |
205 | entropy = 0; | |
206 | initialized = 0; | |
207 | } | |
d02b48c6 | 208 | |
b0700d2c | 209 | static int rand_add(const void *buf, int num, double add) |
0f113f3e MC |
210 | { |
211 | int i, j, k, st_idx; | |
212 | long md_c[2]; | |
213 | unsigned char local_md[MD_DIGEST_LENGTH]; | |
214 | EVP_MD_CTX m; | |
215 | int do_not_lock; | |
216 | int rv = 0; | |
217 | ||
218 | if (!num) | |
219 | return 1; | |
220 | ||
221 | /* | |
222 | * (Based on the rand(3) manpage) | |
223 | * | |
224 | * The input is chopped up into units of 20 bytes (or less for | |
225 | * the last block). Each of these blocks is run through the hash | |
226 | * function as follows: The data passed to the hash function | |
227 | * is the current 'md', the same number of bytes from the 'state' | |
228 | * (the location determined by in incremented looping index) as | |
229 | * the current 'block', the new key data 'block', and 'count' | |
230 | * (which is incremented after each use). | |
231 | * The result of this is kept in 'md' and also xored into the | |
232 | * 'state' at the same locations that were used as input into the | |
233 | * hash function. | |
234 | */ | |
235 | ||
236 | EVP_MD_CTX_init(&m); | |
237 | /* check if we already have the lock */ | |
238 | if (crypto_lock_rand) { | |
239 | CRYPTO_THREADID cur; | |
240 | CRYPTO_THREADID_current(&cur); | |
241 | CRYPTO_r_lock(CRYPTO_LOCK_RAND2); | |
242 | do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); | |
243 | CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); | |
244 | } else | |
245 | do_not_lock = 0; | |
246 | ||
247 | if (!do_not_lock) | |
248 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
249 | st_idx = state_index; | |
250 | ||
251 | /* | |
252 | * use our own copies of the counters so that even if a concurrent thread | |
253 | * seeds with exactly the same data and uses the same subarray there's | |
254 | * _some_ difference | |
255 | */ | |
256 | md_c[0] = md_count[0]; | |
257 | md_c[1] = md_count[1]; | |
258 | ||
259 | memcpy(local_md, md, sizeof md); | |
260 | ||
261 | /* state_index <= state_num <= STATE_SIZE */ | |
262 | state_index += num; | |
263 | if (state_index >= STATE_SIZE) { | |
264 | state_index %= STATE_SIZE; | |
265 | state_num = STATE_SIZE; | |
266 | } else if (state_num < STATE_SIZE) { | |
267 | if (state_index > state_num) | |
268 | state_num = state_index; | |
269 | } | |
270 | /* state_index <= state_num <= STATE_SIZE */ | |
271 | ||
272 | /* | |
273 | * state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE] are what we | |
274 | * will use now, but other threads may use them as well | |
275 | */ | |
276 | ||
277 | md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0); | |
278 | ||
279 | if (!do_not_lock) | |
280 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
281 | ||
282 | for (i = 0; i < num; i += MD_DIGEST_LENGTH) { | |
283 | j = (num - i); | |
284 | j = (j > MD_DIGEST_LENGTH) ? MD_DIGEST_LENGTH : j; | |
285 | ||
286 | if (!MD_Init(&m)) | |
287 | goto err; | |
288 | if (!MD_Update(&m, local_md, MD_DIGEST_LENGTH)) | |
289 | goto err; | |
290 | k = (st_idx + j) - STATE_SIZE; | |
291 | if (k > 0) { | |
292 | if (!MD_Update(&m, &(state[st_idx]), j - k)) | |
293 | goto err; | |
294 | if (!MD_Update(&m, &(state[0]), k)) | |
295 | goto err; | |
296 | } else if (!MD_Update(&m, &(state[st_idx]), j)) | |
297 | goto err; | |
298 | ||
299 | /* DO NOT REMOVE THE FOLLOWING CALL TO MD_Update()! */ | |
300 | if (!MD_Update(&m, buf, j)) | |
301 | goto err; | |
302 | /* | |
303 | * We know that line may cause programs such as purify and valgrind | |
304 | * to complain about use of uninitialized data. The problem is not, | |
305 | * it's with the caller. Removing that line will make sure you get | |
306 | * really bad randomness and thereby other problems such as very | |
307 | * insecure keys. | |
308 | */ | |
309 | ||
310 | if (!MD_Update(&m, (unsigned char *)&(md_c[0]), sizeof(md_c))) | |
311 | goto err; | |
312 | if (!MD_Final(&m, local_md)) | |
313 | goto err; | |
314 | md_c[1]++; | |
315 | ||
316 | buf = (const char *)buf + j; | |
317 | ||
318 | for (k = 0; k < j; k++) { | |
319 | /* | |
320 | * Parallel threads may interfere with this, but always each byte | |
321 | * of the new state is the XOR of some previous value of its and | |
322 | * local_md (itermediate values may be lost). Alway using locking | |
323 | * could hurt performance more than necessary given that | |
324 | * conflicts occur only when the total seeding is longer than the | |
325 | * random state. | |
326 | */ | |
327 | state[st_idx++] ^= local_md[k]; | |
328 | if (st_idx >= STATE_SIZE) | |
329 | st_idx = 0; | |
330 | } | |
331 | } | |
332 | ||
333 | if (!do_not_lock) | |
334 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
335 | /* | |
336 | * Don't just copy back local_md into md -- this could mean that other | |
337 | * thread's seeding remains without effect (except for the incremented | |
338 | * counter). By XORing it we keep at least as much entropy as fits into | |
339 | * md. | |
340 | */ | |
341 | for (k = 0; k < (int)sizeof(md); k++) { | |
342 | md[k] ^= local_md[k]; | |
343 | } | |
344 | if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */ | |
345 | entropy += add; | |
346 | if (!do_not_lock) | |
347 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
348 | ||
bc36ee62 | 349 | #if !defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32) |
0f113f3e | 350 | assert(md_c[1] == md_count[1]); |
c1e744b9 | 351 | #endif |
0f113f3e MC |
352 | rv = 1; |
353 | err: | |
354 | EVP_MD_CTX_cleanup(&m); | |
355 | return rv; | |
356 | } | |
eb952088 | 357 | |
b0700d2c | 358 | static int rand_seed(const void *buf, int num) |
0f113f3e | 359 | { |
b0700d2c | 360 | return rand_add(buf, num, (double)num); |
0f113f3e | 361 | } |
d02b48c6 | 362 | |
b0700d2c | 363 | static int rand_bytes(unsigned char *buf, int num, int pseudo) |
0f113f3e MC |
364 | { |
365 | static volatile int stirred_pool = 0; | |
366 | int i, j, k, st_num, st_idx; | |
367 | int num_ceil; | |
368 | int ok; | |
369 | long md_c[2]; | |
370 | unsigned char local_md[MD_DIGEST_LENGTH]; | |
371 | EVP_MD_CTX m; | |
9a1e34e5 | 372 | #ifndef GETPID_IS_MEANINGLESS |
0f113f3e | 373 | pid_t curr_pid = getpid(); |
c1e744b9 | 374 | #endif |
0f113f3e MC |
375 | time_t curr_time = time(NULL); |
376 | int do_stir_pool = 0; | |
c051e521 DSH |
377 | /* time value for various platforms */ |
378 | #ifdef OPENSSL_SYS_WIN32 | |
0f113f3e | 379 | FILETIME tv; |
c051e521 | 380 | # ifdef _WIN32_WCE |
0f113f3e MC |
381 | SYSTEMTIME t; |
382 | GetSystemTime(&t); | |
383 | SystemTimeToFileTime(&t, &tv); | |
c051e521 | 384 | # else |
0f113f3e | 385 | GetSystemTimeAsFileTime(&tv); |
c051e521 DSH |
386 | # endif |
387 | #elif defined(OPENSSL_SYS_VXWORKS) | |
0f113f3e MC |
388 | struct timespec tv; |
389 | clock_gettime(CLOCK_REALTIME, &ts); | |
68b00c23 | 390 | #elif defined(OPENSSL_SYS_DSPBIOS) |
0f113f3e MC |
391 | unsigned long long tv, OPENSSL_rdtsc(); |
392 | tv = OPENSSL_rdtsc(); | |
c051e521 | 393 | #else |
0f113f3e MC |
394 | struct timeval tv; |
395 | gettimeofday(&tv, NULL); | |
c051e521 | 396 | #endif |
3cd8547a | 397 | |
d02b48c6 | 398 | #ifdef PREDICT |
0f113f3e MC |
399 | if (rand_predictable) { |
400 | static unsigned char val = 0; | |
401 | ||
402 | for (i = 0; i < num; i++) | |
403 | buf[i] = val++; | |
404 | return (1); | |
405 | } | |
d02b48c6 RE |
406 | #endif |
407 | ||
0f113f3e MC |
408 | if (num <= 0) |
409 | return 1; | |
410 | ||
411 | EVP_MD_CTX_init(&m); | |
412 | /* round upwards to multiple of MD_DIGEST_LENGTH/2 */ | |
413 | num_ceil = | |
414 | (1 + (num - 1) / (MD_DIGEST_LENGTH / 2)) * (MD_DIGEST_LENGTH / 2); | |
415 | ||
416 | /* | |
417 | * (Based on the rand(3) manpage:) | |
418 | * | |
419 | * For each group of 10 bytes (or less), we do the following: | |
420 | * | |
421 | * Input into the hash function the local 'md' (which is initialized from | |
422 | * the global 'md' before any bytes are generated), the bytes that are to | |
423 | * be overwritten by the random bytes, and bytes from the 'state' | |
424 | * (incrementing looping index). From this digest output (which is kept | |
425 | * in 'md'), the top (up to) 10 bytes are returned to the caller and the | |
426 | * bottom 10 bytes are xored into the 'state'. | |
427 | * | |
428 | * Finally, after we have finished 'num' random bytes for the | |
429 | * caller, 'count' (which is incremented) and the local and global 'md' | |
430 | * are fed into the hash function and the results are kept in the | |
431 | * global 'md'. | |
432 | */ | |
433 | ||
434 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
435 | ||
b0700d2c | 436 | /* prevent rand_bytes() from trying to obtain the lock again */ |
0f113f3e MC |
437 | CRYPTO_w_lock(CRYPTO_LOCK_RAND2); |
438 | CRYPTO_THREADID_current(&locking_threadid); | |
439 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); | |
440 | crypto_lock_rand = 1; | |
441 | ||
442 | if (!initialized) { | |
443 | RAND_poll(); | |
444 | initialized = 1; | |
445 | } | |
446 | ||
447 | if (!stirred_pool) | |
448 | do_stir_pool = 1; | |
449 | ||
450 | ok = (entropy >= ENTROPY_NEEDED); | |
451 | if (!ok) { | |
452 | /* | |
453 | * If the PRNG state is not yet unpredictable, then seeing the PRNG | |
454 | * output may help attackers to determine the new state; thus we have | |
455 | * to decrease the entropy estimate. Once we've had enough initial | |
456 | * seeding we don't bother to adjust the entropy count, though, | |
457 | * because we're not ambitious to provide *information-theoretic* | |
458 | * randomness. NOTE: This approach fails if the program forks before | |
459 | * we have enough entropy. Entropy should be collected in a separate | |
460 | * input pool and be transferred to the output pool only when the | |
461 | * entropy limit has been reached. | |
462 | */ | |
463 | entropy -= num; | |
464 | if (entropy < 0) | |
465 | entropy = 0; | |
466 | } | |
467 | ||
468 | if (do_stir_pool) { | |
469 | /* | |
470 | * In the output function only half of 'md' remains secret, so we | |
471 | * better make sure that the required entropy gets 'evenly | |
472 | * distributed' through 'state', our randomness pool. The input | |
b0700d2c | 473 | * function (rand_add) chains all of 'md', which makes it more |
0f113f3e MC |
474 | * suitable for this purpose. |
475 | */ | |
476 | ||
477 | int n = STATE_SIZE; /* so that the complete pool gets accessed */ | |
478 | while (n > 0) { | |
361ee973 BM |
479 | #if MD_DIGEST_LENGTH > 20 |
480 | # error "Please adjust DUMMY_SEED." | |
481 | #endif | |
482 | #define DUMMY_SEED "...................." /* at least MD_DIGEST_LENGTH */ | |
0f113f3e MC |
483 | /* |
484 | * Note that the seed does not matter, it's just that | |
b0700d2c | 485 | * rand_add expects to have something to hash. |
0f113f3e | 486 | */ |
b0700d2c | 487 | rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0); |
0f113f3e MC |
488 | n -= MD_DIGEST_LENGTH; |
489 | } | |
490 | if (ok) | |
491 | stirred_pool = 1; | |
492 | } | |
493 | ||
494 | st_idx = state_index; | |
495 | st_num = state_num; | |
496 | md_c[0] = md_count[0]; | |
497 | md_c[1] = md_count[1]; | |
498 | memcpy(local_md, md, sizeof md); | |
499 | ||
500 | state_index += num_ceil; | |
501 | if (state_index > state_num) | |
502 | state_index %= state_num; | |
503 | ||
504 | /* | |
505 | * state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num] are now | |
506 | * ours (but other threads may use them too) | |
507 | */ | |
508 | ||
509 | md_count[0] += 1; | |
510 | ||
511 | /* before unlocking, we must clear 'crypto_lock_rand' */ | |
512 | crypto_lock_rand = 0; | |
513 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
514 | ||
515 | while (num > 0) { | |
516 | /* num_ceil -= MD_DIGEST_LENGTH/2 */ | |
517 | j = (num >= MD_DIGEST_LENGTH / 2) ? MD_DIGEST_LENGTH / 2 : num; | |
518 | num -= j; | |
519 | if (!MD_Init(&m)) | |
520 | goto err; | |
9a1e34e5 | 521 | #ifndef GETPID_IS_MEANINGLESS |
0f113f3e MC |
522 | if (curr_pid) { /* just in the first iteration to save time */ |
523 | if (!MD_Update(&m, (unsigned char *)&curr_pid, sizeof curr_pid)) | |
524 | goto err; | |
525 | curr_pid = 0; | |
526 | } | |
62ac2938 | 527 | #endif |
0f113f3e MC |
528 | if (curr_time) { /* just in the first iteration to save time */ |
529 | if (!MD_Update(&m, (unsigned char *)&curr_time, sizeof curr_time)) | |
530 | goto err; | |
531 | if (!MD_Update(&m, (unsigned char *)&tv, sizeof tv)) | |
532 | goto err; | |
533 | curr_time = 0; | |
534 | rand_hw_seed(&m); | |
535 | } | |
536 | if (!MD_Update(&m, local_md, MD_DIGEST_LENGTH)) | |
537 | goto err; | |
538 | if (!MD_Update(&m, (unsigned char *)&(md_c[0]), sizeof(md_c))) | |
539 | goto err; | |
540 | ||
541 | #ifndef PURIFY /* purify complains */ | |
542 | /* | |
543 | * The following line uses the supplied buffer as a small source of | |
544 | * entropy: since this buffer is often uninitialised it may cause | |
545 | * programs such as purify or valgrind to complain. So for those | |
546 | * builds it is not used: the removal of such a small source of | |
547 | * entropy has negligible impact on security. | |
548 | */ | |
549 | if (!MD_Update(&m, buf, j)) | |
550 | goto err; | |
d02b48c6 | 551 | #endif |
792bbc23 | 552 | |
0f113f3e MC |
553 | k = (st_idx + MD_DIGEST_LENGTH / 2) - st_num; |
554 | if (k > 0) { | |
555 | if (!MD_Update(&m, &(state[st_idx]), MD_DIGEST_LENGTH / 2 - k)) | |
556 | goto err; | |
557 | if (!MD_Update(&m, &(state[0]), k)) | |
558 | goto err; | |
559 | } else if (!MD_Update(&m, &(state[st_idx]), MD_DIGEST_LENGTH / 2)) | |
560 | goto err; | |
561 | if (!MD_Final(&m, local_md)) | |
562 | goto err; | |
563 | ||
564 | for (i = 0; i < MD_DIGEST_LENGTH / 2; i++) { | |
565 | /* may compete with other threads */ | |
566 | state[st_idx++] ^= local_md[i]; | |
567 | if (st_idx >= st_num) | |
568 | st_idx = 0; | |
569 | if (i < j) | |
570 | *(buf++) = local_md[i + MD_DIGEST_LENGTH / 2]; | |
571 | } | |
572 | } | |
573 | ||
574 | if (!MD_Init(&m) | |
575 | || !MD_Update(&m, (unsigned char *)&(md_c[0]), sizeof(md_c)) | |
576 | || !MD_Update(&m, local_md, MD_DIGEST_LENGTH)) | |
577 | goto err; | |
578 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
579 | if (!MD_Update(&m, md, MD_DIGEST_LENGTH) || !MD_Final(&m, md)) { | |
580 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
581 | goto err; | |
582 | } | |
583 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
584 | ||
585 | EVP_MD_CTX_cleanup(&m); | |
586 | if (ok) | |
587 | return (1); | |
588 | else if (pseudo) | |
589 | return 0; | |
590 | else { | |
b0700d2c | 591 | RANDerr(RAND_F_RAND_BYTES, RAND_R_PRNG_NOT_SEEDED); |
0f113f3e MC |
592 | ERR_add_error_data(1, "You need to read the OpenSSL FAQ, " |
593 | "http://www.openssl.org/support/faq.html"); | |
594 | return (0); | |
595 | } | |
596 | err: | |
597 | EVP_MD_CTX_cleanup(&m); | |
b0700d2c | 598 | RANDerr(RAND_F_RAND_BYTES, ERR_R_EVP_LIB); |
0f113f3e MC |
599 | return 0; |
600 | ||
601 | } | |
d02b48c6 | 602 | |
b0700d2c | 603 | static int rand_nopseudo_bytes(unsigned char *buf, int num) |
0f113f3e | 604 | { |
b0700d2c | 605 | return rand_bytes(buf, num, 0); |
0f113f3e | 606 | } |
4ead4e52 | 607 | |
302d38e3 | 608 | #ifndef OPENSSL_NO_DEPRECATED |
0f113f3e MC |
609 | /* |
610 | * pseudo-random bytes that are guaranteed to be unique but not unpredictable | |
611 | */ | |
b0700d2c | 612 | static int rand_pseudo_bytes(unsigned char *buf, int num) |
0f113f3e | 613 | { |
b0700d2c | 614 | return rand_bytes(buf, num, 1); |
0f113f3e | 615 | } |
302d38e3 | 616 | #endif |
373b575f | 617 | |
b0700d2c | 618 | static int rand_status(void) |
0f113f3e MC |
619 | { |
620 | CRYPTO_THREADID cur; | |
621 | int ret; | |
622 | int do_not_lock; | |
623 | ||
624 | CRYPTO_THREADID_current(&cur); | |
625 | /* | |
626 | * check if we already have the lock (could happen if a RAND_poll() | |
627 | * implementation calls RAND_status()) | |
628 | */ | |
629 | if (crypto_lock_rand) { | |
630 | CRYPTO_r_lock(CRYPTO_LOCK_RAND2); | |
631 | do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); | |
632 | CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); | |
633 | } else | |
634 | do_not_lock = 0; | |
635 | ||
636 | if (!do_not_lock) { | |
637 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
638 | ||
639 | /* | |
b0700d2c | 640 | * prevent rand_bytes() from trying to obtain the lock again |
0f113f3e MC |
641 | */ |
642 | CRYPTO_w_lock(CRYPTO_LOCK_RAND2); | |
643 | CRYPTO_THREADID_cpy(&locking_threadid, &cur); | |
644 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); | |
645 | crypto_lock_rand = 1; | |
646 | } | |
647 | ||
648 | if (!initialized) { | |
649 | RAND_poll(); | |
650 | initialized = 1; | |
651 | } | |
652 | ||
653 | ret = entropy >= ENTROPY_NEEDED; | |
654 | ||
655 | if (!do_not_lock) { | |
656 | /* before unlocking, we must clear 'crypto_lock_rand' */ | |
657 | crypto_lock_rand = 0; | |
658 | ||
659 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
660 | } | |
661 | ||
662 | return ret; | |
663 | } | |
664 | ||
665 | /* | |
666 | * rand_hw_seed: get seed data from any available hardware RNG. only | |
667 | * currently supports rdrand. | |
ef643cc7 DSH |
668 | */ |
669 | ||
670 | /* Adapted from eng_rdrand.c */ | |
671 | ||
672 | #if (defined(__i386) || defined(__i386__) || defined(_M_IX86) || \ | |
673 | defined(__x86_64) || defined(__x86_64__) || \ | |
674 | defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ) | |
675 | ||
0f113f3e | 676 | # define RDRAND_CALLS 4 |
ef643cc7 DSH |
677 | |
678 | size_t OPENSSL_ia32_rdrand(void); | |
679 | extern unsigned int OPENSSL_ia32cap_P[]; | |
680 | ||
681 | static void rand_hw_seed(EVP_MD_CTX *ctx) | |
0f113f3e MC |
682 | { |
683 | int i; | |
684 | if (!(OPENSSL_ia32cap_P[1] & (1 << (62 - 32)))) | |
685 | return; | |
686 | for (i = 0; i < RDRAND_CALLS; i++) { | |
687 | size_t rnd; | |
688 | rnd = OPENSSL_ia32_rdrand(); | |
689 | if (rnd == 0) | |
690 | return; | |
691 | MD_Update(ctx, (unsigned char *)&rnd, sizeof(size_t)); | |
692 | } | |
693 | } | |
ef643cc7 DSH |
694 | |
695 | /* XOR an existing buffer with random data */ | |
696 | ||
697 | void rand_hw_xor(unsigned char *buf, size_t num) | |
0f113f3e MC |
698 | { |
699 | size_t rnd; | |
700 | if (!(OPENSSL_ia32cap_P[1] & (1 << (62 - 32)))) | |
701 | return; | |
702 | while (num >= sizeof(size_t)) { | |
703 | rnd = OPENSSL_ia32_rdrand(); | |
704 | if (rnd == 0) | |
705 | return; | |
706 | *((size_t *)buf) ^= rnd; | |
707 | buf += sizeof(size_t); | |
708 | num -= sizeof(size_t); | |
709 | } | |
710 | if (num) { | |
711 | rnd = OPENSSL_ia32_rdrand(); | |
712 | if (rnd == 0) | |
713 | return; | |
714 | while (num) { | |
715 | *buf ^= rnd & 0xff; | |
716 | rnd >>= 8; | |
717 | buf++; | |
718 | num--; | |
719 | } | |
720 | } | |
721 | } | |
ef643cc7 DSH |
722 | |
723 | #else | |
724 | ||
725 | static void rand_hw_seed(EVP_MD_CTX *ctx) | |
0f113f3e MC |
726 | { |
727 | return; | |
728 | } | |
ef643cc7 DSH |
729 | |
730 | void rand_hw_xor(unsigned char *buf, size_t num) | |
0f113f3e MC |
731 | { |
732 | return; | |
733 | } | |
ef643cc7 DSH |
734 | |
735 | #endif |