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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 | |
c051e521 DSH |
124 | #if !(defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYSNAME_DSPBIOS)) |
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 | ||
0f113f3e | 167 | const char RAND_version[] = "RAND" OPENSSL_VERSION_PTEXT; |
d02b48c6 | 168 | |
ef643cc7 DSH |
169 | static void rand_hw_seed(EVP_MD_CTX *ctx); |
170 | ||
dfeab068 | 171 | static void ssleay_rand_cleanup(void); |
b6dcdbfc DSH |
172 | static int ssleay_rand_seed(const void *buf, int num); |
173 | static int ssleay_rand_add(const void *buf, int num, double add_entropy); | |
4ead4e52 DSH |
174 | static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo); |
175 | static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num); | |
6343829a | 176 | static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num); |
5eb8ca4d | 177 | static int ssleay_rand_status(void); |
dfeab068 | 178 | |
0f113f3e MC |
179 | static RAND_METHOD rand_ssleay_meth = { |
180 | ssleay_rand_seed, | |
181 | ssleay_rand_nopseudo_bytes, | |
182 | ssleay_rand_cleanup, | |
183 | ssleay_rand_add, | |
184 | ssleay_rand_pseudo_bytes, | |
185 | ssleay_rand_status | |
186 | }; | |
dfeab068 | 187 | |
6b691a5c | 188 | RAND_METHOD *RAND_SSLeay(void) |
0f113f3e MC |
189 | { |
190 | return (&rand_ssleay_meth); | |
191 | } | |
dfeab068 | 192 | |
6b691a5c | 193 | static void ssleay_rand_cleanup(void) |
0f113f3e MC |
194 | { |
195 | OPENSSL_cleanse(state, sizeof(state)); | |
196 | state_num = 0; | |
197 | state_index = 0; | |
198 | OPENSSL_cleanse(md, MD_DIGEST_LENGTH); | |
199 | md_count[0] = 0; | |
200 | md_count[1] = 0; | |
201 | entropy = 0; | |
202 | initialized = 0; | |
203 | } | |
d02b48c6 | 204 | |
b6dcdbfc | 205 | static int ssleay_rand_add(const void *buf, int num, double add) |
0f113f3e MC |
206 | { |
207 | int i, j, k, st_idx; | |
208 | long md_c[2]; | |
209 | unsigned char local_md[MD_DIGEST_LENGTH]; | |
210 | EVP_MD_CTX m; | |
211 | int do_not_lock; | |
212 | int rv = 0; | |
213 | ||
214 | if (!num) | |
215 | return 1; | |
216 | ||
217 | /* | |
218 | * (Based on the rand(3) manpage) | |
219 | * | |
220 | * The input is chopped up into units of 20 bytes (or less for | |
221 | * the last block). Each of these blocks is run through the hash | |
222 | * function as follows: The data passed to the hash function | |
223 | * is the current 'md', the same number of bytes from the 'state' | |
224 | * (the location determined by in incremented looping index) as | |
225 | * the current 'block', the new key data 'block', and 'count' | |
226 | * (which is incremented after each use). | |
227 | * The result of this is kept in 'md' and also xored into the | |
228 | * 'state' at the same locations that were used as input into the | |
229 | * hash function. | |
230 | */ | |
231 | ||
232 | EVP_MD_CTX_init(&m); | |
233 | /* check if we already have the lock */ | |
234 | if (crypto_lock_rand) { | |
235 | CRYPTO_THREADID cur; | |
236 | CRYPTO_THREADID_current(&cur); | |
237 | CRYPTO_r_lock(CRYPTO_LOCK_RAND2); | |
238 | do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); | |
239 | CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); | |
240 | } else | |
241 | do_not_lock = 0; | |
242 | ||
243 | if (!do_not_lock) | |
244 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
245 | st_idx = state_index; | |
246 | ||
247 | /* | |
248 | * use our own copies of the counters so that even if a concurrent thread | |
249 | * seeds with exactly the same data and uses the same subarray there's | |
250 | * _some_ difference | |
251 | */ | |
252 | md_c[0] = md_count[0]; | |
253 | md_c[1] = md_count[1]; | |
254 | ||
255 | memcpy(local_md, md, sizeof md); | |
256 | ||
257 | /* state_index <= state_num <= STATE_SIZE */ | |
258 | state_index += num; | |
259 | if (state_index >= STATE_SIZE) { | |
260 | state_index %= STATE_SIZE; | |
261 | state_num = STATE_SIZE; | |
262 | } else if (state_num < STATE_SIZE) { | |
263 | if (state_index > state_num) | |
264 | state_num = state_index; | |
265 | } | |
266 | /* state_index <= state_num <= STATE_SIZE */ | |
267 | ||
268 | /* | |
269 | * state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE] are what we | |
270 | * will use now, but other threads may use them as well | |
271 | */ | |
272 | ||
273 | md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0); | |
274 | ||
275 | if (!do_not_lock) | |
276 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
277 | ||
278 | for (i = 0; i < num; i += MD_DIGEST_LENGTH) { | |
279 | j = (num - i); | |
280 | j = (j > MD_DIGEST_LENGTH) ? MD_DIGEST_LENGTH : j; | |
281 | ||
282 | if (!MD_Init(&m)) | |
283 | goto err; | |
284 | if (!MD_Update(&m, local_md, MD_DIGEST_LENGTH)) | |
285 | goto err; | |
286 | k = (st_idx + j) - STATE_SIZE; | |
287 | if (k > 0) { | |
288 | if (!MD_Update(&m, &(state[st_idx]), j - k)) | |
289 | goto err; | |
290 | if (!MD_Update(&m, &(state[0]), k)) | |
291 | goto err; | |
292 | } else if (!MD_Update(&m, &(state[st_idx]), j)) | |
293 | goto err; | |
294 | ||
295 | /* DO NOT REMOVE THE FOLLOWING CALL TO MD_Update()! */ | |
296 | if (!MD_Update(&m, buf, j)) | |
297 | goto err; | |
298 | /* | |
299 | * We know that line may cause programs such as purify and valgrind | |
300 | * to complain about use of uninitialized data. The problem is not, | |
301 | * it's with the caller. Removing that line will make sure you get | |
302 | * really bad randomness and thereby other problems such as very | |
303 | * insecure keys. | |
304 | */ | |
305 | ||
306 | if (!MD_Update(&m, (unsigned char *)&(md_c[0]), sizeof(md_c))) | |
307 | goto err; | |
308 | if (!MD_Final(&m, local_md)) | |
309 | goto err; | |
310 | md_c[1]++; | |
311 | ||
312 | buf = (const char *)buf + j; | |
313 | ||
314 | for (k = 0; k < j; k++) { | |
315 | /* | |
316 | * Parallel threads may interfere with this, but always each byte | |
317 | * of the new state is the XOR of some previous value of its and | |
318 | * local_md (itermediate values may be lost). Alway using locking | |
319 | * could hurt performance more than necessary given that | |
320 | * conflicts occur only when the total seeding is longer than the | |
321 | * random state. | |
322 | */ | |
323 | state[st_idx++] ^= local_md[k]; | |
324 | if (st_idx >= STATE_SIZE) | |
325 | st_idx = 0; | |
326 | } | |
327 | } | |
328 | ||
329 | if (!do_not_lock) | |
330 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
331 | /* | |
332 | * Don't just copy back local_md into md -- this could mean that other | |
333 | * thread's seeding remains without effect (except for the incremented | |
334 | * counter). By XORing it we keep at least as much entropy as fits into | |
335 | * md. | |
336 | */ | |
337 | for (k = 0; k < (int)sizeof(md); k++) { | |
338 | md[k] ^= local_md[k]; | |
339 | } | |
340 | if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */ | |
341 | entropy += add; | |
342 | if (!do_not_lock) | |
343 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
344 | ||
bc36ee62 | 345 | #if !defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32) |
0f113f3e | 346 | assert(md_c[1] == md_count[1]); |
c1e744b9 | 347 | #endif |
0f113f3e MC |
348 | rv = 1; |
349 | err: | |
350 | EVP_MD_CTX_cleanup(&m); | |
351 | return rv; | |
352 | } | |
eb952088 | 353 | |
b6dcdbfc | 354 | static int ssleay_rand_seed(const void *buf, int num) |
0f113f3e MC |
355 | { |
356 | return ssleay_rand_add(buf, num, (double)num); | |
357 | } | |
d02b48c6 | 358 | |
4ead4e52 | 359 | static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo) |
0f113f3e MC |
360 | { |
361 | static volatile int stirred_pool = 0; | |
362 | int i, j, k, st_num, st_idx; | |
363 | int num_ceil; | |
364 | int ok; | |
365 | long md_c[2]; | |
366 | unsigned char local_md[MD_DIGEST_LENGTH]; | |
367 | EVP_MD_CTX m; | |
9a1e34e5 | 368 | #ifndef GETPID_IS_MEANINGLESS |
0f113f3e | 369 | pid_t curr_pid = getpid(); |
c1e744b9 | 370 | #endif |
0f113f3e MC |
371 | time_t curr_time = time(NULL); |
372 | int do_stir_pool = 0; | |
c051e521 DSH |
373 | /* time value for various platforms */ |
374 | #ifdef OPENSSL_SYS_WIN32 | |
0f113f3e | 375 | FILETIME tv; |
c051e521 | 376 | # ifdef _WIN32_WCE |
0f113f3e MC |
377 | SYSTEMTIME t; |
378 | GetSystemTime(&t); | |
379 | SystemTimeToFileTime(&t, &tv); | |
c051e521 | 380 | # else |
0f113f3e | 381 | GetSystemTimeAsFileTime(&tv); |
c051e521 DSH |
382 | # endif |
383 | #elif defined(OPENSSL_SYS_VXWORKS) | |
0f113f3e MC |
384 | struct timespec tv; |
385 | clock_gettime(CLOCK_REALTIME, &ts); | |
c051e521 | 386 | #elif defined(OPENSSL_SYSNAME_DSPBIOS) |
0f113f3e MC |
387 | unsigned long long tv, OPENSSL_rdtsc(); |
388 | tv = OPENSSL_rdtsc(); | |
c051e521 | 389 | #else |
0f113f3e MC |
390 | struct timeval tv; |
391 | gettimeofday(&tv, NULL); | |
c051e521 | 392 | #endif |
3cd8547a | 393 | |
d02b48c6 | 394 | #ifdef PREDICT |
0f113f3e MC |
395 | if (rand_predictable) { |
396 | static unsigned char val = 0; | |
397 | ||
398 | for (i = 0; i < num; i++) | |
399 | buf[i] = val++; | |
400 | return (1); | |
401 | } | |
d02b48c6 RE |
402 | #endif |
403 | ||
0f113f3e MC |
404 | if (num <= 0) |
405 | return 1; | |
406 | ||
407 | EVP_MD_CTX_init(&m); | |
408 | /* round upwards to multiple of MD_DIGEST_LENGTH/2 */ | |
409 | num_ceil = | |
410 | (1 + (num - 1) / (MD_DIGEST_LENGTH / 2)) * (MD_DIGEST_LENGTH / 2); | |
411 | ||
412 | /* | |
413 | * (Based on the rand(3) manpage:) | |
414 | * | |
415 | * For each group of 10 bytes (or less), we do the following: | |
416 | * | |
417 | * Input into the hash function the local 'md' (which is initialized from | |
418 | * the global 'md' before any bytes are generated), the bytes that are to | |
419 | * be overwritten by the random bytes, and bytes from the 'state' | |
420 | * (incrementing looping index). From this digest output (which is kept | |
421 | * in 'md'), the top (up to) 10 bytes are returned to the caller and the | |
422 | * bottom 10 bytes are xored into the 'state'. | |
423 | * | |
424 | * Finally, after we have finished 'num' random bytes for the | |
425 | * caller, 'count' (which is incremented) and the local and global 'md' | |
426 | * are fed into the hash function and the results are kept in the | |
427 | * global 'md'. | |
428 | */ | |
429 | ||
430 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
431 | ||
432 | /* prevent ssleay_rand_bytes() from trying to obtain the lock again */ | |
433 | CRYPTO_w_lock(CRYPTO_LOCK_RAND2); | |
434 | CRYPTO_THREADID_current(&locking_threadid); | |
435 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); | |
436 | crypto_lock_rand = 1; | |
437 | ||
438 | if (!initialized) { | |
439 | RAND_poll(); | |
440 | initialized = 1; | |
441 | } | |
442 | ||
443 | if (!stirred_pool) | |
444 | do_stir_pool = 1; | |
445 | ||
446 | ok = (entropy >= ENTROPY_NEEDED); | |
447 | if (!ok) { | |
448 | /* | |
449 | * If the PRNG state is not yet unpredictable, then seeing the PRNG | |
450 | * output may help attackers to determine the new state; thus we have | |
451 | * to decrease the entropy estimate. Once we've had enough initial | |
452 | * seeding we don't bother to adjust the entropy count, though, | |
453 | * because we're not ambitious to provide *information-theoretic* | |
454 | * randomness. NOTE: This approach fails if the program forks before | |
455 | * we have enough entropy. Entropy should be collected in a separate | |
456 | * input pool and be transferred to the output pool only when the | |
457 | * entropy limit has been reached. | |
458 | */ | |
459 | entropy -= num; | |
460 | if (entropy < 0) | |
461 | entropy = 0; | |
462 | } | |
463 | ||
464 | if (do_stir_pool) { | |
465 | /* | |
466 | * In the output function only half of 'md' remains secret, so we | |
467 | * better make sure that the required entropy gets 'evenly | |
468 | * distributed' through 'state', our randomness pool. The input | |
469 | * function (ssleay_rand_add) chains all of 'md', which makes it more | |
470 | * suitable for this purpose. | |
471 | */ | |
472 | ||
473 | int n = STATE_SIZE; /* so that the complete pool gets accessed */ | |
474 | while (n > 0) { | |
361ee973 BM |
475 | #if MD_DIGEST_LENGTH > 20 |
476 | # error "Please adjust DUMMY_SEED." | |
477 | #endif | |
478 | #define DUMMY_SEED "...................." /* at least MD_DIGEST_LENGTH */ | |
0f113f3e MC |
479 | /* |
480 | * Note that the seed does not matter, it's just that | |
481 | * ssleay_rand_add expects to have something to hash. | |
482 | */ | |
483 | ssleay_rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0); | |
484 | n -= MD_DIGEST_LENGTH; | |
485 | } | |
486 | if (ok) | |
487 | stirred_pool = 1; | |
488 | } | |
489 | ||
490 | st_idx = state_index; | |
491 | st_num = state_num; | |
492 | md_c[0] = md_count[0]; | |
493 | md_c[1] = md_count[1]; | |
494 | memcpy(local_md, md, sizeof md); | |
495 | ||
496 | state_index += num_ceil; | |
497 | if (state_index > state_num) | |
498 | state_index %= state_num; | |
499 | ||
500 | /* | |
501 | * state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num] are now | |
502 | * ours (but other threads may use them too) | |
503 | */ | |
504 | ||
505 | md_count[0] += 1; | |
506 | ||
507 | /* before unlocking, we must clear 'crypto_lock_rand' */ | |
508 | crypto_lock_rand = 0; | |
509 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
510 | ||
511 | while (num > 0) { | |
512 | /* num_ceil -= MD_DIGEST_LENGTH/2 */ | |
513 | j = (num >= MD_DIGEST_LENGTH / 2) ? MD_DIGEST_LENGTH / 2 : num; | |
514 | num -= j; | |
515 | if (!MD_Init(&m)) | |
516 | goto err; | |
9a1e34e5 | 517 | #ifndef GETPID_IS_MEANINGLESS |
0f113f3e MC |
518 | if (curr_pid) { /* just in the first iteration to save time */ |
519 | if (!MD_Update(&m, (unsigned char *)&curr_pid, sizeof curr_pid)) | |
520 | goto err; | |
521 | curr_pid = 0; | |
522 | } | |
62ac2938 | 523 | #endif |
0f113f3e MC |
524 | if (curr_time) { /* just in the first iteration to save time */ |
525 | if (!MD_Update(&m, (unsigned char *)&curr_time, sizeof curr_time)) | |
526 | goto err; | |
527 | if (!MD_Update(&m, (unsigned char *)&tv, sizeof tv)) | |
528 | goto err; | |
529 | curr_time = 0; | |
530 | rand_hw_seed(&m); | |
531 | } | |
532 | if (!MD_Update(&m, local_md, MD_DIGEST_LENGTH)) | |
533 | goto err; | |
534 | if (!MD_Update(&m, (unsigned char *)&(md_c[0]), sizeof(md_c))) | |
535 | goto err; | |
536 | ||
537 | #ifndef PURIFY /* purify complains */ | |
538 | /* | |
539 | * The following line uses the supplied buffer as a small source of | |
540 | * entropy: since this buffer is often uninitialised it may cause | |
541 | * programs such as purify or valgrind to complain. So for those | |
542 | * builds it is not used: the removal of such a small source of | |
543 | * entropy has negligible impact on security. | |
544 | */ | |
545 | if (!MD_Update(&m, buf, j)) | |
546 | goto err; | |
d02b48c6 | 547 | #endif |
792bbc23 | 548 | |
0f113f3e MC |
549 | k = (st_idx + MD_DIGEST_LENGTH / 2) - st_num; |
550 | if (k > 0) { | |
551 | if (!MD_Update(&m, &(state[st_idx]), MD_DIGEST_LENGTH / 2 - k)) | |
552 | goto err; | |
553 | if (!MD_Update(&m, &(state[0]), k)) | |
554 | goto err; | |
555 | } else if (!MD_Update(&m, &(state[st_idx]), MD_DIGEST_LENGTH / 2)) | |
556 | goto err; | |
557 | if (!MD_Final(&m, local_md)) | |
558 | goto err; | |
559 | ||
560 | for (i = 0; i < MD_DIGEST_LENGTH / 2; i++) { | |
561 | /* may compete with other threads */ | |
562 | state[st_idx++] ^= local_md[i]; | |
563 | if (st_idx >= st_num) | |
564 | st_idx = 0; | |
565 | if (i < j) | |
566 | *(buf++) = local_md[i + MD_DIGEST_LENGTH / 2]; | |
567 | } | |
568 | } | |
569 | ||
570 | if (!MD_Init(&m) | |
571 | || !MD_Update(&m, (unsigned char *)&(md_c[0]), sizeof(md_c)) | |
572 | || !MD_Update(&m, local_md, MD_DIGEST_LENGTH)) | |
573 | goto err; | |
574 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
575 | if (!MD_Update(&m, md, MD_DIGEST_LENGTH) || !MD_Final(&m, md)) { | |
576 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
577 | goto err; | |
578 | } | |
579 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
580 | ||
581 | EVP_MD_CTX_cleanup(&m); | |
582 | if (ok) | |
583 | return (1); | |
584 | else if (pseudo) | |
585 | return 0; | |
586 | else { | |
587 | RANDerr(RAND_F_SSLEAY_RAND_BYTES, RAND_R_PRNG_NOT_SEEDED); | |
588 | ERR_add_error_data(1, "You need to read the OpenSSL FAQ, " | |
589 | "http://www.openssl.org/support/faq.html"); | |
590 | return (0); | |
591 | } | |
592 | err: | |
593 | EVP_MD_CTX_cleanup(&m); | |
594 | RANDerr(RAND_F_SSLEAY_RAND_BYTES, ERR_R_EVP_LIB); | |
595 | return 0; | |
596 | ||
597 | } | |
d02b48c6 | 598 | |
4ead4e52 | 599 | static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num) |
0f113f3e MC |
600 | { |
601 | return ssleay_rand_bytes(buf, num, 0); | |
602 | } | |
4ead4e52 | 603 | |
0f113f3e MC |
604 | /* |
605 | * pseudo-random bytes that are guaranteed to be unique but not unpredictable | |
606 | */ | |
607 | static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) | |
608 | { | |
609 | return ssleay_rand_bytes(buf, num, 1); | |
610 | } | |
373b575f | 611 | |
5eb8ca4d | 612 | static int ssleay_rand_status(void) |
0f113f3e MC |
613 | { |
614 | CRYPTO_THREADID cur; | |
615 | int ret; | |
616 | int do_not_lock; | |
617 | ||
618 | CRYPTO_THREADID_current(&cur); | |
619 | /* | |
620 | * check if we already have the lock (could happen if a RAND_poll() | |
621 | * implementation calls RAND_status()) | |
622 | */ | |
623 | if (crypto_lock_rand) { | |
624 | CRYPTO_r_lock(CRYPTO_LOCK_RAND2); | |
625 | do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); | |
626 | CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); | |
627 | } else | |
628 | do_not_lock = 0; | |
629 | ||
630 | if (!do_not_lock) { | |
631 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
632 | ||
633 | /* | |
634 | * prevent ssleay_rand_bytes() from trying to obtain the lock again | |
635 | */ | |
636 | CRYPTO_w_lock(CRYPTO_LOCK_RAND2); | |
637 | CRYPTO_THREADID_cpy(&locking_threadid, &cur); | |
638 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); | |
639 | crypto_lock_rand = 1; | |
640 | } | |
641 | ||
642 | if (!initialized) { | |
643 | RAND_poll(); | |
644 | initialized = 1; | |
645 | } | |
646 | ||
647 | ret = entropy >= ENTROPY_NEEDED; | |
648 | ||
649 | if (!do_not_lock) { | |
650 | /* before unlocking, we must clear 'crypto_lock_rand' */ | |
651 | crypto_lock_rand = 0; | |
652 | ||
653 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
654 | } | |
655 | ||
656 | return ret; | |
657 | } | |
658 | ||
659 | /* | |
660 | * rand_hw_seed: get seed data from any available hardware RNG. only | |
661 | * currently supports rdrand. | |
ef643cc7 DSH |
662 | */ |
663 | ||
664 | /* Adapted from eng_rdrand.c */ | |
665 | ||
666 | #if (defined(__i386) || defined(__i386__) || defined(_M_IX86) || \ | |
667 | defined(__x86_64) || defined(__x86_64__) || \ | |
668 | defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ) | |
669 | ||
0f113f3e | 670 | # define RDRAND_CALLS 4 |
ef643cc7 DSH |
671 | |
672 | size_t OPENSSL_ia32_rdrand(void); | |
673 | extern unsigned int OPENSSL_ia32cap_P[]; | |
674 | ||
675 | static void rand_hw_seed(EVP_MD_CTX *ctx) | |
0f113f3e MC |
676 | { |
677 | int i; | |
678 | if (!(OPENSSL_ia32cap_P[1] & (1 << (62 - 32)))) | |
679 | return; | |
680 | for (i = 0; i < RDRAND_CALLS; i++) { | |
681 | size_t rnd; | |
682 | rnd = OPENSSL_ia32_rdrand(); | |
683 | if (rnd == 0) | |
684 | return; | |
685 | MD_Update(ctx, (unsigned char *)&rnd, sizeof(size_t)); | |
686 | } | |
687 | } | |
ef643cc7 DSH |
688 | |
689 | /* XOR an existing buffer with random data */ | |
690 | ||
691 | void rand_hw_xor(unsigned char *buf, size_t num) | |
0f113f3e MC |
692 | { |
693 | size_t rnd; | |
694 | if (!(OPENSSL_ia32cap_P[1] & (1 << (62 - 32)))) | |
695 | return; | |
696 | while (num >= sizeof(size_t)) { | |
697 | rnd = OPENSSL_ia32_rdrand(); | |
698 | if (rnd == 0) | |
699 | return; | |
700 | *((size_t *)buf) ^= rnd; | |
701 | buf += sizeof(size_t); | |
702 | num -= sizeof(size_t); | |
703 | } | |
704 | if (num) { | |
705 | rnd = OPENSSL_ia32_rdrand(); | |
706 | if (rnd == 0) | |
707 | return; | |
708 | while (num) { | |
709 | *buf ^= rnd & 0xff; | |
710 | rnd >>= 8; | |
711 | buf++; | |
712 | num--; | |
713 | } | |
714 | } | |
715 | } | |
ef643cc7 DSH |
716 | |
717 | #else | |
718 | ||
719 | static void rand_hw_seed(EVP_MD_CTX *ctx) | |
0f113f3e MC |
720 | { |
721 | return; | |
722 | } | |
ef643cc7 DSH |
723 | |
724 | void rand_hw_xor(unsigned char *buf, size_t num) | |
0f113f3e MC |
725 | { |
726 | return; | |
727 | } | |
ef643cc7 DSH |
728 | |
729 | #endif |