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58964a49 | 1 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
d02b48c6 RE |
2 | * All rights reserved. |
3 | * | |
4 | * This package is an SSL implementation written | |
5 | * by Eric Young (eay@cryptsoft.com). | |
6 | * The implementation was written so as to conform with Netscapes SSL. | |
0f113f3e | 7 | * |
d02b48c6 RE |
8 | * This library is free for commercial and non-commercial use as long as |
9 | * the following conditions are aheared to. The following conditions | |
10 | * apply to all code found in this distribution, be it the RC4, RSA, | |
11 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation | |
12 | * included with this distribution is covered by the same copyright terms | |
13 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). | |
0f113f3e | 14 | * |
d02b48c6 RE |
15 | * Copyright remains Eric Young's, and as such any Copyright notices in |
16 | * the code are not to be removed. | |
17 | * If this package is used in a product, Eric Young should be given attribution | |
18 | * as the author of the parts of the library used. | |
19 | * This can be in the form of a textual message at program startup or | |
20 | * in documentation (online or textual) provided with the package. | |
0f113f3e | 21 | * |
d02b48c6 RE |
22 | * Redistribution and use in source and binary forms, with or without |
23 | * modification, are permitted provided that the following conditions | |
24 | * are met: | |
25 | * 1. Redistributions of source code must retain the copyright | |
26 | * notice, this list of conditions and the following disclaimer. | |
27 | * 2. Redistributions in binary form must reproduce the above copyright | |
28 | * notice, this list of conditions and the following disclaimer in the | |
29 | * documentation and/or other materials provided with the distribution. | |
30 | * 3. All advertising materials mentioning features or use of this software | |
31 | * must display the following acknowledgement: | |
32 | * "This product includes cryptographic software written by | |
33 | * Eric Young (eay@cryptsoft.com)" | |
34 | * The word 'cryptographic' can be left out if the rouines from the library | |
35 | * being used are not cryptographic related :-). | |
0f113f3e | 36 | * 4. If you include any Windows specific code (or a derivative thereof) from |
d02b48c6 RE |
37 | * the apps directory (application code) you must include an acknowledgement: |
38 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
0f113f3e | 39 | * |
d02b48c6 RE |
40 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
41 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
42 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
43 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |
44 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
45 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
46 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
47 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
48 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
49 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
50 | * SUCH DAMAGE. | |
0f113f3e | 51 | * |
d02b48c6 RE |
52 | * The licence and distribution terms for any publically available version or |
53 | * derivative of this code cannot be changed. i.e. this code cannot simply be | |
54 | * copied and put under another distribution licence | |
55 | * [including the GNU Public Licence.] | |
56 | */ | |
863fe2ec | 57 | /* ==================================================================== |
f9b0f47c | 58 | * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved. |
863fe2ec BM |
59 | * |
60 | * Redistribution and use in source and binary forms, with or without | |
61 | * modification, are permitted provided that the following conditions | |
62 | * are met: | |
63 | * | |
64 | * 1. Redistributions of source code must retain the above copyright | |
0f113f3e | 65 | * notice, this list of conditions and the following disclaimer. |
863fe2ec BM |
66 | * |
67 | * 2. Redistributions in binary form must reproduce the above copyright | |
68 | * notice, this list of conditions and the following disclaimer in | |
69 | * the documentation and/or other materials provided with the | |
70 | * distribution. | |
71 | * | |
72 | * 3. All advertising materials mentioning features or use of this | |
73 | * software must display the following acknowledgment: | |
74 | * "This product includes software developed by the OpenSSL Project | |
75 | * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" | |
76 | * | |
77 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to | |
78 | * endorse or promote products derived from this software without | |
79 | * prior written permission. For written permission, please contact | |
80 | * openssl-core@openssl.org. | |
81 | * | |
82 | * 5. Products derived from this software may not be called "OpenSSL" | |
83 | * nor may "OpenSSL" appear in their names without prior written | |
84 | * permission of the OpenSSL Project. | |
85 | * | |
86 | * 6. Redistributions of any form whatsoever must retain the following | |
87 | * acknowledgment: | |
88 | * "This product includes software developed by the OpenSSL Project | |
89 | * for use in the OpenSSL Toolkit (http://www.openssl.org/)" | |
90 | * | |
91 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY | |
92 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
93 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
94 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR | |
95 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
96 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
97 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
98 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
99 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
100 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
101 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | |
102 | * OF THE POSSIBILITY OF SUCH DAMAGE. | |
103 | * ==================================================================== | |
104 | * | |
105 | * This product includes cryptographic software written by Eric Young | |
106 | * (eay@cryptsoft.com). This product includes software written by Tim | |
107 | * Hudson (tjh@cryptsoft.com). | |
108 | * | |
109 | */ | |
d02b48c6 | 110 | |
2ace287d | 111 | #ifdef MD_RAND_DEBUG |
c1e744b9 | 112 | # ifndef NDEBUG |
0f113f3e | 113 | # define NDEBUG |
c1e744b9 BM |
114 | # endif |
115 | #endif | |
116 | ||
117 | #include <assert.h> | |
d02b48c6 | 118 | #include <stdio.h> |
a224de3f | 119 | #include <string.h> |
17e3dd1c | 120 | |
41d2a336 | 121 | #include "e_os.h" |
17e3dd1c | 122 | |
68b00c23 | 123 | #if !(defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_DSPBIOS)) |
c051e521 DSH |
124 | # include <sys/time.h> |
125 | #endif | |
126 | #if defined(OPENSSL_SYS_VXWORKS) | |
127 | # include <time.h> | |
128 | #endif | |
129 | ||
98186eb4 | 130 | #include <openssl/opensslconf.h> |
d749e108 | 131 | #include <openssl/crypto.h> |
8ad7635e | 132 | #include <openssl/rand.h> |
625146d9 | 133 | #include <openssl/async.h> |
8ad7635e UM |
134 | #include "rand_lcl.h" |
135 | ||
eb952088 | 136 | #include <openssl/err.h> |
d02b48c6 | 137 | |
aa87945f | 138 | #ifdef OPENSSL_FIPS |
0f113f3e | 139 | # include <openssl/fips.h> |
aa87945f DSH |
140 | #endif |
141 | ||
e64dceab UM |
142 | #ifdef BN_DEBUG |
143 | # define PREDICT | |
144 | #endif | |
145 | ||
0f113f3e | 146 | /* #define PREDICT 1 */ |
d02b48c6 | 147 | |
0f113f3e MC |
148 | #define STATE_SIZE 1023 |
149 | static int state_num = 0, state_index = 0; | |
150 | static unsigned char state[STATE_SIZE + MD_DIGEST_LENGTH]; | |
d02b48c6 | 151 | static unsigned char md[MD_DIGEST_LENGTH]; |
0f113f3e MC |
152 | static long md_count[2] = { 0, 0 }; |
153 | ||
154 | static double entropy = 0; | |
155 | static int initialized = 0; | |
d02b48c6 | 156 | |
6e6d04e2 | 157 | static unsigned int crypto_lock_rand = 0; /* may be set only when a thread |
0f113f3e MC |
158 | * holds CRYPTO_LOCK_RAND (to |
159 | * prevent double locking) */ | |
daba492c | 160 | /* access to lockin_thread is synchronized by CRYPTO_LOCK_RAND2 */ |
68d39f3c MC |
161 | /* valid iff crypto_lock_rand is set */ |
162 | static CRYPTO_THREADID locking_threadid; | |
6e6d04e2 | 163 | |
e64dceab | 164 | #ifdef PREDICT |
0f113f3e | 165 | int rand_predictable = 0; |
e64dceab UM |
166 | #endif |
167 | ||
ef643cc7 DSH |
168 | static void rand_hw_seed(EVP_MD_CTX *ctx); |
169 | ||
b0700d2c RS |
170 | static void rand_cleanup(void); |
171 | static int rand_seed(const void *buf, int num); | |
172 | static int rand_add(const void *buf, int num, double add_entropy); | |
173 | static int rand_bytes(unsigned char *buf, int num, int pseudo); | |
174 | static int rand_nopseudo_bytes(unsigned char *buf, int num); | |
98186eb4 | 175 | #if OPENSSL_API_COMPAT < 0x10100000L |
b0700d2c | 176 | static int rand_pseudo_bytes(unsigned char *buf, int num); |
302d38e3 | 177 | #endif |
b0700d2c | 178 | static int rand_status(void); |
dfeab068 | 179 | |
b0700d2c RS |
180 | static RAND_METHOD rand_meth = { |
181 | rand_seed, | |
182 | rand_nopseudo_bytes, | |
183 | rand_cleanup, | |
184 | rand_add, | |
98186eb4 | 185 | #if OPENSSL_API_COMPAT < 0x10100000L |
b0700d2c | 186 | rand_pseudo_bytes, |
302d38e3 MC |
187 | #else |
188 | NULL, | |
189 | #endif | |
b0700d2c | 190 | rand_status |
0f113f3e | 191 | }; |
dfeab068 | 192 | |
b0700d2c | 193 | RAND_METHOD *RAND_OpenSSL(void) |
0f113f3e | 194 | { |
b0700d2c | 195 | return (&rand_meth); |
0f113f3e | 196 | } |
dfeab068 | 197 | |
b0700d2c | 198 | static void rand_cleanup(void) |
0f113f3e MC |
199 | { |
200 | OPENSSL_cleanse(state, sizeof(state)); | |
201 | state_num = 0; | |
202 | state_index = 0; | |
203 | OPENSSL_cleanse(md, MD_DIGEST_LENGTH); | |
204 | md_count[0] = 0; | |
205 | md_count[1] = 0; | |
206 | entropy = 0; | |
207 | initialized = 0; | |
208 | } | |
d02b48c6 | 209 | |
b0700d2c | 210 | static int rand_add(const void *buf, int num, double add) |
0f113f3e MC |
211 | { |
212 | int i, j, k, st_idx; | |
213 | long md_c[2]; | |
214 | unsigned char local_md[MD_DIGEST_LENGTH]; | |
6e59a892 | 215 | EVP_MD_CTX *m; |
0f113f3e MC |
216 | int do_not_lock; |
217 | int rv = 0; | |
218 | ||
219 | if (!num) | |
220 | return 1; | |
221 | ||
222 | /* | |
223 | * (Based on the rand(3) manpage) | |
224 | * | |
225 | * The input is chopped up into units of 20 bytes (or less for | |
226 | * the last block). Each of these blocks is run through the hash | |
227 | * function as follows: The data passed to the hash function | |
228 | * is the current 'md', the same number of bytes from the 'state' | |
229 | * (the location determined by in incremented looping index) as | |
230 | * the current 'block', the new key data 'block', and 'count' | |
231 | * (which is incremented after each use). | |
232 | * The result of this is kept in 'md' and also xored into the | |
233 | * 'state' at the same locations that were used as input into the | |
234 | * hash function. | |
235 | */ | |
236 | ||
bfb0641f | 237 | m = EVP_MD_CTX_new(); |
6e59a892 RL |
238 | if (m == NULL) |
239 | goto err; | |
240 | ||
0f113f3e MC |
241 | /* check if we already have the lock */ |
242 | if (crypto_lock_rand) { | |
243 | CRYPTO_THREADID cur; | |
244 | CRYPTO_THREADID_current(&cur); | |
245 | CRYPTO_r_lock(CRYPTO_LOCK_RAND2); | |
246 | do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); | |
247 | CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); | |
248 | } else | |
249 | do_not_lock = 0; | |
250 | ||
251 | if (!do_not_lock) | |
252 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
253 | st_idx = state_index; | |
254 | ||
255 | /* | |
256 | * use our own copies of the counters so that even if a concurrent thread | |
257 | * seeds with exactly the same data and uses the same subarray there's | |
258 | * _some_ difference | |
259 | */ | |
260 | md_c[0] = md_count[0]; | |
261 | md_c[1] = md_count[1]; | |
262 | ||
263 | memcpy(local_md, md, sizeof md); | |
264 | ||
265 | /* state_index <= state_num <= STATE_SIZE */ | |
266 | state_index += num; | |
267 | if (state_index >= STATE_SIZE) { | |
268 | state_index %= STATE_SIZE; | |
269 | state_num = STATE_SIZE; | |
270 | } else if (state_num < STATE_SIZE) { | |
271 | if (state_index > state_num) | |
272 | state_num = state_index; | |
273 | } | |
274 | /* state_index <= state_num <= STATE_SIZE */ | |
275 | ||
276 | /* | |
277 | * state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE] are what we | |
278 | * will use now, but other threads may use them as well | |
279 | */ | |
280 | ||
281 | md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0); | |
282 | ||
283 | if (!do_not_lock) | |
284 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
285 | ||
286 | for (i = 0; i < num; i += MD_DIGEST_LENGTH) { | |
287 | j = (num - i); | |
288 | j = (j > MD_DIGEST_LENGTH) ? MD_DIGEST_LENGTH : j; | |
289 | ||
6e59a892 | 290 | if (!MD_Init(m)) |
0f113f3e | 291 | goto err; |
6e59a892 | 292 | if (!MD_Update(m, local_md, MD_DIGEST_LENGTH)) |
0f113f3e MC |
293 | goto err; |
294 | k = (st_idx + j) - STATE_SIZE; | |
295 | if (k > 0) { | |
6e59a892 | 296 | if (!MD_Update(m, &(state[st_idx]), j - k)) |
0f113f3e | 297 | goto err; |
6e59a892 | 298 | if (!MD_Update(m, &(state[0]), k)) |
0f113f3e | 299 | goto err; |
6e59a892 | 300 | } else if (!MD_Update(m, &(state[st_idx]), j)) |
0f113f3e MC |
301 | goto err; |
302 | ||
303 | /* DO NOT REMOVE THE FOLLOWING CALL TO MD_Update()! */ | |
6e59a892 | 304 | if (!MD_Update(m, buf, j)) |
0f113f3e MC |
305 | goto err; |
306 | /* | |
307 | * We know that line may cause programs such as purify and valgrind | |
308 | * to complain about use of uninitialized data. The problem is not, | |
309 | * it's with the caller. Removing that line will make sure you get | |
310 | * really bad randomness and thereby other problems such as very | |
311 | * insecure keys. | |
312 | */ | |
313 | ||
6e59a892 | 314 | if (!MD_Update(m, (unsigned char *)&(md_c[0]), sizeof(md_c))) |
0f113f3e | 315 | goto err; |
6e59a892 | 316 | if (!MD_Final(m, local_md)) |
0f113f3e MC |
317 | goto err; |
318 | md_c[1]++; | |
319 | ||
320 | buf = (const char *)buf + j; | |
321 | ||
322 | for (k = 0; k < j; k++) { | |
323 | /* | |
324 | * Parallel threads may interfere with this, but always each byte | |
325 | * of the new state is the XOR of some previous value of its and | |
326 | * local_md (itermediate values may be lost). Alway using locking | |
327 | * could hurt performance more than necessary given that | |
328 | * conflicts occur only when the total seeding is longer than the | |
329 | * random state. | |
330 | */ | |
331 | state[st_idx++] ^= local_md[k]; | |
332 | if (st_idx >= STATE_SIZE) | |
333 | st_idx = 0; | |
334 | } | |
335 | } | |
336 | ||
337 | if (!do_not_lock) | |
338 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
339 | /* | |
340 | * Don't just copy back local_md into md -- this could mean that other | |
341 | * thread's seeding remains without effect (except for the incremented | |
342 | * counter). By XORing it we keep at least as much entropy as fits into | |
343 | * md. | |
344 | */ | |
345 | for (k = 0; k < (int)sizeof(md); k++) { | |
346 | md[k] ^= local_md[k]; | |
347 | } | |
348 | if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */ | |
349 | entropy += add; | |
350 | if (!do_not_lock) | |
351 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); | |
352 | ||
bc36ee62 | 353 | #if !defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32) |
0f113f3e | 354 | assert(md_c[1] == md_count[1]); |
c1e744b9 | 355 | #endif |
0f113f3e MC |
356 | rv = 1; |
357 | err: | |
bfb0641f | 358 | EVP_MD_CTX_free(m); |
0f113f3e MC |
359 | return rv; |
360 | } | |
eb952088 | 361 | |
b0700d2c | 362 | static int rand_seed(const void *buf, int num) |
0f113f3e | 363 | { |
b0700d2c | 364 | return rand_add(buf, num, (double)num); |
0f113f3e | 365 | } |
d02b48c6 | 366 | |
b0700d2c | 367 | static int rand_bytes(unsigned char *buf, int num, int pseudo) |
0f113f3e MC |
368 | { |
369 | static volatile int stirred_pool = 0; | |
370 | int i, j, k, st_num, st_idx; | |
371 | int num_ceil; | |
372 | int ok; | |
373 | long md_c[2]; | |
374 | unsigned char local_md[MD_DIGEST_LENGTH]; | |
6e59a892 | 375 | EVP_MD_CTX *m; |
9a1e34e5 | 376 | #ifndef GETPID_IS_MEANINGLESS |
0f113f3e | 377 | pid_t curr_pid = getpid(); |
c1e744b9 | 378 | #endif |
0f113f3e MC |
379 | time_t curr_time = time(NULL); |
380 | int do_stir_pool = 0; | |
c051e521 DSH |
381 | /* time value for various platforms */ |
382 | #ifdef OPENSSL_SYS_WIN32 | |
0f113f3e | 383 | FILETIME tv; |
c051e521 | 384 | # ifdef _WIN32_WCE |
0f113f3e MC |
385 | SYSTEMTIME t; |
386 | GetSystemTime(&t); | |
387 | SystemTimeToFileTime(&t, &tv); | |
c051e521 | 388 | # else |
0f113f3e | 389 | GetSystemTimeAsFileTime(&tv); |
c051e521 DSH |
390 | # endif |
391 | #elif defined(OPENSSL_SYS_VXWORKS) | |
0f113f3e MC |
392 | struct timespec tv; |
393 | clock_gettime(CLOCK_REALTIME, &ts); | |
68b00c23 | 394 | #elif defined(OPENSSL_SYS_DSPBIOS) |
0f113f3e MC |
395 | unsigned long long tv, OPENSSL_rdtsc(); |
396 | tv = OPENSSL_rdtsc(); | |
c051e521 | 397 | #else |
0f113f3e MC |
398 | struct timeval tv; |
399 | gettimeofday(&tv, NULL); | |
c051e521 | 400 | #endif |
3cd8547a | 401 | |
d02b48c6 | 402 | #ifdef PREDICT |
0f113f3e MC |
403 | if (rand_predictable) { |
404 | static unsigned char val = 0; | |
405 | ||
406 | for (i = 0; i < num; i++) | |
407 | buf[i] = val++; | |
408 | return (1); | |
409 | } | |
d02b48c6 RE |
410 | #endif |
411 | ||
0f113f3e MC |
412 | if (num <= 0) |
413 | return 1; | |
414 | ||
bfb0641f | 415 | m = EVP_MD_CTX_new(); |
6e59a892 RL |
416 | if (m == NULL) |
417 | goto err_mem; | |
418 | ||
0f113f3e MC |
419 | /* round upwards to multiple of MD_DIGEST_LENGTH/2 */ |
420 | num_ceil = | |
421 | (1 + (num - 1) / (MD_DIGEST_LENGTH / 2)) * (MD_DIGEST_LENGTH / 2); | |
422 | ||
423 | /* | |
424 | * (Based on the rand(3) manpage:) | |
425 | * | |
426 | * For each group of 10 bytes (or less), we do the following: | |
427 | * | |
428 | * Input into the hash function the local 'md' (which is initialized from | |
429 | * the global 'md' before any bytes are generated), the bytes that are to | |
430 | * be overwritten by the random bytes, and bytes from the 'state' | |
431 | * (incrementing looping index). From this digest output (which is kept | |
432 | * in 'md'), the top (up to) 10 bytes are returned to the caller and the | |
433 | * bottom 10 bytes are xored into the 'state'. | |
434 | * | |
435 | * Finally, after we have finished 'num' random bytes for the | |
436 | * caller, 'count' (which is incremented) and the local and global 'md' | |
437 | * are fed into the hash function and the results are kept in the | |
438 | * global 'md'. | |
439 | */ | |
440 | ||
441 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
625146d9 MC |
442 | /* |
443 | * We could end up in an async engine while holding this lock so ensure | |
444 | * we don't pause and cause a deadlock | |
445 | */ | |
446 | ASYNC_block_pause(); | |
0f113f3e | 447 | |
b0700d2c | 448 | /* prevent rand_bytes() from trying to obtain the lock again */ |
0f113f3e MC |
449 | CRYPTO_w_lock(CRYPTO_LOCK_RAND2); |
450 | CRYPTO_THREADID_current(&locking_threadid); | |
451 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); | |
452 | crypto_lock_rand = 1; | |
453 | ||
454 | if (!initialized) { | |
455 | RAND_poll(); | |
456 | initialized = 1; | |
457 | } | |
458 | ||
459 | if (!stirred_pool) | |
460 | do_stir_pool = 1; | |
461 | ||
462 | ok = (entropy >= ENTROPY_NEEDED); | |
463 | if (!ok) { | |
464 | /* | |
465 | * If the PRNG state is not yet unpredictable, then seeing the PRNG | |
466 | * output may help attackers to determine the new state; thus we have | |
467 | * to decrease the entropy estimate. Once we've had enough initial | |
468 | * seeding we don't bother to adjust the entropy count, though, | |
469 | * because we're not ambitious to provide *information-theoretic* | |
470 | * randomness. NOTE: This approach fails if the program forks before | |
471 | * we have enough entropy. Entropy should be collected in a separate | |
472 | * input pool and be transferred to the output pool only when the | |
473 | * entropy limit has been reached. | |
474 | */ | |
475 | entropy -= num; | |
476 | if (entropy < 0) | |
477 | entropy = 0; | |
478 | } | |
479 | ||
480 | if (do_stir_pool) { | |
481 | /* | |
482 | * In the output function only half of 'md' remains secret, so we | |
483 | * better make sure that the required entropy gets 'evenly | |
484 | * distributed' through 'state', our randomness pool. The input | |
b0700d2c | 485 | * function (rand_add) chains all of 'md', which makes it more |
0f113f3e MC |
486 | * suitable for this purpose. |
487 | */ | |
488 | ||
489 | int n = STATE_SIZE; /* so that the complete pool gets accessed */ | |
490 | while (n > 0) { | |
361ee973 BM |
491 | #if MD_DIGEST_LENGTH > 20 |
492 | # error "Please adjust DUMMY_SEED." | |
493 | #endif | |
494 | #define DUMMY_SEED "...................." /* at least MD_DIGEST_LENGTH */ | |
0f113f3e MC |
495 | /* |
496 | * Note that the seed does not matter, it's just that | |
b0700d2c | 497 | * rand_add expects to have something to hash. |
0f113f3e | 498 | */ |
b0700d2c | 499 | rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0); |
0f113f3e MC |
500 | n -= MD_DIGEST_LENGTH; |
501 | } | |
502 | if (ok) | |
503 | stirred_pool = 1; | |
504 | } | |
505 | ||
506 | st_idx = state_index; | |
507 | st_num = state_num; | |
508 | md_c[0] = md_count[0]; | |
509 | md_c[1] = md_count[1]; | |
510 | memcpy(local_md, md, sizeof md); | |
511 | ||
512 | state_index += num_ceil; | |
513 | if (state_index > state_num) | |
514 | state_index %= state_num; | |
515 | ||
516 | /* | |
517 | * state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num] are now | |
518 | * ours (but other threads may use them too) | |
519 | */ | |
520 | ||
521 | md_count[0] += 1; | |
522 | ||
523 | /* before unlocking, we must clear 'crypto_lock_rand' */ | |
524 | crypto_lock_rand = 0; | |
625146d9 | 525 | ASYNC_unblock_pause(); |
0f113f3e MC |
526 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); |
527 | ||
528 | while (num > 0) { | |
529 | /* num_ceil -= MD_DIGEST_LENGTH/2 */ | |
530 | j = (num >= MD_DIGEST_LENGTH / 2) ? MD_DIGEST_LENGTH / 2 : num; | |
531 | num -= j; | |
6e59a892 | 532 | if (!MD_Init(m)) |
0f113f3e | 533 | goto err; |
9a1e34e5 | 534 | #ifndef GETPID_IS_MEANINGLESS |
0f113f3e | 535 | if (curr_pid) { /* just in the first iteration to save time */ |
6e59a892 | 536 | if (!MD_Update(m, (unsigned char *)&curr_pid, sizeof curr_pid)) |
0f113f3e MC |
537 | goto err; |
538 | curr_pid = 0; | |
539 | } | |
62ac2938 | 540 | #endif |
0f113f3e | 541 | if (curr_time) { /* just in the first iteration to save time */ |
6e59a892 | 542 | if (!MD_Update(m, (unsigned char *)&curr_time, sizeof curr_time)) |
0f113f3e | 543 | goto err; |
6e59a892 | 544 | if (!MD_Update(m, (unsigned char *)&tv, sizeof tv)) |
0f113f3e MC |
545 | goto err; |
546 | curr_time = 0; | |
6e59a892 | 547 | rand_hw_seed(m); |
0f113f3e | 548 | } |
6e59a892 | 549 | if (!MD_Update(m, local_md, MD_DIGEST_LENGTH)) |
0f113f3e | 550 | goto err; |
6e59a892 | 551 | if (!MD_Update(m, (unsigned char *)&(md_c[0]), sizeof(md_c))) |
0f113f3e MC |
552 | goto err; |
553 | ||
554 | #ifndef PURIFY /* purify complains */ | |
555 | /* | |
556 | * The following line uses the supplied buffer as a small source of | |
557 | * entropy: since this buffer is often uninitialised it may cause | |
558 | * programs such as purify or valgrind to complain. So for those | |
559 | * builds it is not used: the removal of such a small source of | |
560 | * entropy has negligible impact on security. | |
561 | */ | |
6e59a892 | 562 | if (!MD_Update(m, buf, j)) |
0f113f3e | 563 | goto err; |
d02b48c6 | 564 | #endif |
792bbc23 | 565 | |
0f113f3e MC |
566 | k = (st_idx + MD_DIGEST_LENGTH / 2) - st_num; |
567 | if (k > 0) { | |
6e59a892 | 568 | if (!MD_Update(m, &(state[st_idx]), MD_DIGEST_LENGTH / 2 - k)) |
0f113f3e | 569 | goto err; |
6e59a892 | 570 | if (!MD_Update(m, &(state[0]), k)) |
0f113f3e | 571 | goto err; |
6e59a892 | 572 | } else if (!MD_Update(m, &(state[st_idx]), MD_DIGEST_LENGTH / 2)) |
0f113f3e | 573 | goto err; |
6e59a892 | 574 | if (!MD_Final(m, local_md)) |
0f113f3e MC |
575 | goto err; |
576 | ||
577 | for (i = 0; i < MD_DIGEST_LENGTH / 2; i++) { | |
578 | /* may compete with other threads */ | |
579 | state[st_idx++] ^= local_md[i]; | |
580 | if (st_idx >= st_num) | |
581 | st_idx = 0; | |
582 | if (i < j) | |
583 | *(buf++) = local_md[i + MD_DIGEST_LENGTH / 2]; | |
584 | } | |
585 | } | |
586 | ||
6e59a892 RL |
587 | if (!MD_Init(m) |
588 | || !MD_Update(m, (unsigned char *)&(md_c[0]), sizeof(md_c)) | |
589 | || !MD_Update(m, local_md, MD_DIGEST_LENGTH)) | |
0f113f3e MC |
590 | goto err; |
591 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
625146d9 MC |
592 | /* |
593 | * Prevent deadlocks if we end up in an async engine | |
594 | */ | |
595 | ASYNC_block_pause(); | |
6e59a892 | 596 | if (!MD_Update(m, md, MD_DIGEST_LENGTH) || !MD_Final(m, md)) { |
0f113f3e MC |
597 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); |
598 | goto err; | |
599 | } | |
625146d9 | 600 | ASYNC_unblock_pause(); |
0f113f3e MC |
601 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); |
602 | ||
bfb0641f | 603 | EVP_MD_CTX_free(m); |
0f113f3e MC |
604 | if (ok) |
605 | return (1); | |
606 | else if (pseudo) | |
607 | return 0; | |
608 | else { | |
b0700d2c | 609 | RANDerr(RAND_F_RAND_BYTES, RAND_R_PRNG_NOT_SEEDED); |
0f113f3e MC |
610 | ERR_add_error_data(1, "You need to read the OpenSSL FAQ, " |
611 | "http://www.openssl.org/support/faq.html"); | |
612 | return (0); | |
613 | } | |
614 | err: | |
b0700d2c | 615 | RANDerr(RAND_F_RAND_BYTES, ERR_R_EVP_LIB); |
bfb0641f | 616 | EVP_MD_CTX_free(m); |
6e59a892 RL |
617 | return 0; |
618 | err_mem: | |
619 | RANDerr(RAND_F_RAND_BYTES, ERR_R_MALLOC_FAILURE); | |
bfb0641f | 620 | EVP_MD_CTX_free(m); |
0f113f3e MC |
621 | return 0; |
622 | ||
623 | } | |
d02b48c6 | 624 | |
b0700d2c | 625 | static int rand_nopseudo_bytes(unsigned char *buf, int num) |
0f113f3e | 626 | { |
b0700d2c | 627 | return rand_bytes(buf, num, 0); |
0f113f3e | 628 | } |
4ead4e52 | 629 | |
98186eb4 | 630 | #if OPENSSL_API_COMPAT < 0x10100000L |
0f113f3e MC |
631 | /* |
632 | * pseudo-random bytes that are guaranteed to be unique but not unpredictable | |
633 | */ | |
b0700d2c | 634 | static int rand_pseudo_bytes(unsigned char *buf, int num) |
0f113f3e | 635 | { |
b0700d2c | 636 | return rand_bytes(buf, num, 1); |
0f113f3e | 637 | } |
302d38e3 | 638 | #endif |
373b575f | 639 | |
b0700d2c | 640 | static int rand_status(void) |
0f113f3e MC |
641 | { |
642 | CRYPTO_THREADID cur; | |
643 | int ret; | |
644 | int do_not_lock; | |
645 | ||
646 | CRYPTO_THREADID_current(&cur); | |
647 | /* | |
648 | * check if we already have the lock (could happen if a RAND_poll() | |
649 | * implementation calls RAND_status()) | |
650 | */ | |
651 | if (crypto_lock_rand) { | |
652 | CRYPTO_r_lock(CRYPTO_LOCK_RAND2); | |
653 | do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); | |
654 | CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); | |
655 | } else | |
656 | do_not_lock = 0; | |
657 | ||
658 | if (!do_not_lock) { | |
659 | CRYPTO_w_lock(CRYPTO_LOCK_RAND); | |
625146d9 MC |
660 | /* |
661 | * Prevent deadlocks in case we end up in an async engine | |
662 | */ | |
663 | ASYNC_block_pause(); | |
0f113f3e MC |
664 | |
665 | /* | |
b0700d2c | 666 | * prevent rand_bytes() from trying to obtain the lock again |
0f113f3e MC |
667 | */ |
668 | CRYPTO_w_lock(CRYPTO_LOCK_RAND2); | |
669 | CRYPTO_THREADID_cpy(&locking_threadid, &cur); | |
670 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); | |
671 | crypto_lock_rand = 1; | |
672 | } | |
673 | ||
674 | if (!initialized) { | |
675 | RAND_poll(); | |
676 | initialized = 1; | |
677 | } | |
678 | ||
679 | ret = entropy >= ENTROPY_NEEDED; | |
680 | ||
681 | if (!do_not_lock) { | |
682 | /* before unlocking, we must clear 'crypto_lock_rand' */ | |
683 | crypto_lock_rand = 0; | |
684 | ||
625146d9 | 685 | ASYNC_unblock_pause(); |
0f113f3e MC |
686 | CRYPTO_w_unlock(CRYPTO_LOCK_RAND); |
687 | } | |
688 | ||
689 | return ret; | |
690 | } | |
691 | ||
692 | /* | |
693 | * rand_hw_seed: get seed data from any available hardware RNG. only | |
694 | * currently supports rdrand. | |
ef643cc7 DSH |
695 | */ |
696 | ||
697 | /* Adapted from eng_rdrand.c */ | |
698 | ||
699 | #if (defined(__i386) || defined(__i386__) || defined(_M_IX86) || \ | |
700 | defined(__x86_64) || defined(__x86_64__) || \ | |
701 | defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ) | |
702 | ||
0f113f3e | 703 | # define RDRAND_CALLS 4 |
ef643cc7 DSH |
704 | |
705 | size_t OPENSSL_ia32_rdrand(void); | |
706 | extern unsigned int OPENSSL_ia32cap_P[]; | |
707 | ||
708 | static void rand_hw_seed(EVP_MD_CTX *ctx) | |
0f113f3e MC |
709 | { |
710 | int i; | |
711 | if (!(OPENSSL_ia32cap_P[1] & (1 << (62 - 32)))) | |
712 | return; | |
713 | for (i = 0; i < RDRAND_CALLS; i++) { | |
714 | size_t rnd; | |
715 | rnd = OPENSSL_ia32_rdrand(); | |
716 | if (rnd == 0) | |
717 | return; | |
718 | MD_Update(ctx, (unsigned char *)&rnd, sizeof(size_t)); | |
719 | } | |
720 | } | |
ef643cc7 DSH |
721 | |
722 | /* XOR an existing buffer with random data */ | |
723 | ||
724 | void rand_hw_xor(unsigned char *buf, size_t num) | |
0f113f3e MC |
725 | { |
726 | size_t rnd; | |
727 | if (!(OPENSSL_ia32cap_P[1] & (1 << (62 - 32)))) | |
728 | return; | |
729 | while (num >= sizeof(size_t)) { | |
730 | rnd = OPENSSL_ia32_rdrand(); | |
731 | if (rnd == 0) | |
732 | return; | |
733 | *((size_t *)buf) ^= rnd; | |
734 | buf += sizeof(size_t); | |
735 | num -= sizeof(size_t); | |
736 | } | |
737 | if (num) { | |
738 | rnd = OPENSSL_ia32_rdrand(); | |
739 | if (rnd == 0) | |
740 | return; | |
741 | while (num) { | |
742 | *buf ^= rnd & 0xff; | |
743 | rnd >>= 8; | |
744 | buf++; | |
745 | num--; | |
746 | } | |
747 | } | |
748 | } | |
ef643cc7 DSH |
749 | |
750 | #else | |
751 | ||
752 | static void rand_hw_seed(EVP_MD_CTX *ctx) | |
0f113f3e MC |
753 | { |
754 | return; | |
755 | } | |
ef643cc7 DSH |
756 | |
757 | void rand_hw_xor(unsigned char *buf, size_t num) | |
0f113f3e MC |
758 | { |
759 | return; | |
760 | } | |
ef643cc7 DSH |
761 | |
762 | #endif |