1 /* crypto/rand/md_rand.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
58 /* ====================================================================
59 * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved.
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
65 * 1. Redistributions of source code must retain the above copyright
66 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
87 * 6. Redistributions of any form whatsoever must retain the following
89 * "This product includes software developed by the OpenSSL Project
90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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 * ====================================================================
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).
112 #define OPENSSL_FIPSAPI
126 #if !(defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYSNAME_DSPBIOS))
127 # include <sys/time.h>
129 #if defined(OPENSSL_SYS_VXWORKS)
133 #include <openssl/crypto.h>
134 #include <openssl/rand.h>
135 #include "rand_lcl.h"
137 #include <openssl/err.h>
140 #include <openssl/fips.h>
147 /* #define PREDICT 1 */
149 #define STATE_SIZE 1023
150 static int state_num=0,state_index=0;
151 static unsigned char state[STATE_SIZE+MD_DIGEST_LENGTH];
152 static unsigned char md[MD_DIGEST_LENGTH];
153 static long md_count[2]={0,0};
154 static double entropy=0;
155 static int initialized=0;
157 static unsigned int crypto_lock_rand = 0; /* may be set only when a thread
158 * holds CRYPTO_LOCK_RAND
159 * (to prevent double locking) */
160 /* access to lockin_thread is synchronized by CRYPTO_LOCK_RAND2 */
161 static CRYPTO_THREADID locking_threadid; /* valid iff crypto_lock_rand is set */
165 int rand_predictable=0;
168 const char RAND_version[]="RAND" OPENSSL_VERSION_PTEXT;
170 static void rand_hw_seed(EVP_MD_CTX *ctx);
172 static void ssleay_rand_cleanup(void);
173 static int ssleay_rand_seed(const void *buf, int num);
174 static int ssleay_rand_add(const void *buf, int num, double add_entropy);
175 static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo);
176 static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num);
177 static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num);
178 static int ssleay_rand_status(void);
180 static RAND_METHOD rand_ssleay_meth={
182 ssleay_rand_nopseudo_bytes,
185 ssleay_rand_pseudo_bytes,
189 RAND_METHOD *RAND_SSLeay(void)
191 return(&rand_ssleay_meth);
194 static void ssleay_rand_cleanup(void)
196 OPENSSL_cleanse(state,sizeof(state));
199 OPENSSL_cleanse(md,MD_DIGEST_LENGTH);
206 static int ssleay_rand_add(const void *buf, int num, double add)
210 unsigned char local_md[MD_DIGEST_LENGTH];
216 * (Based on the rand(3) manpage)
218 * The input is chopped up into units of 20 bytes (or less for
219 * the last block). Each of these blocks is run through the hash
220 * function as follows: The data passed to the hash function
221 * is the current 'md', the same number of bytes from the 'state'
222 * (the location determined by in incremented looping index) as
223 * the current 'block', the new key data 'block', and 'count'
224 * (which is incremented after each use).
225 * The result of this is kept in 'md' and also xored into the
226 * 'state' at the same locations that were used as input into the
231 /* check if we already have the lock */
232 if (crypto_lock_rand)
235 CRYPTO_THREADID_current(&cur);
236 CRYPTO_r_lock(CRYPTO_LOCK_RAND2);
237 do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur);
238 CRYPTO_r_unlock(CRYPTO_LOCK_RAND2);
243 if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND);
246 /* use our own copies of the counters so that even
247 * if a concurrent thread seeds with exactly the
248 * same data and uses the same subarray there's _some_
250 md_c[0] = md_count[0];
251 md_c[1] = md_count[1];
253 memcpy(local_md, md, sizeof md);
255 /* state_index <= state_num <= STATE_SIZE */
257 if (state_index >= STATE_SIZE)
259 state_index%=STATE_SIZE;
260 state_num=STATE_SIZE;
262 else if (state_num < STATE_SIZE)
264 if (state_index > state_num)
265 state_num=state_index;
267 /* state_index <= state_num <= STATE_SIZE */
269 /* state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE]
270 * are what we will use now, but other threads may use them
273 md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0);
275 if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
277 for (i=0; i<num; i+=MD_DIGEST_LENGTH)
280 j=(j > MD_DIGEST_LENGTH)?MD_DIGEST_LENGTH:j;
284 if (!MD_Update(&m,local_md,MD_DIGEST_LENGTH))
286 k=(st_idx+j)-STATE_SIZE;
289 if (!MD_Update(&m,&(state[st_idx]),j-k))
291 if (!MD_Update(&m,&(state[0]),k))
295 if (!MD_Update(&m,&(state[st_idx]),j))
298 /* DO NOT REMOVE THE FOLLOWING CALL TO MD_Update()! */
299 if (!MD_Update(&m,buf,j))
301 /* We know that line may cause programs such as
302 purify and valgrind to complain about use of
303 uninitialized data. The problem is not, it's
304 with the caller. Removing that line will make
305 sure you get really bad randomness and thereby
306 other problems such as very insecure keys. */
308 if (!MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)))
310 if (!MD_Final(&m,local_md))
314 buf=(const char *)buf + j;
318 /* Parallel threads may interfere with this,
319 * but always each byte of the new state is
320 * the XOR of some previous value of its
321 * and local_md (itermediate values may be lost).
322 * Alway using locking could hurt performance more
323 * than necessary given that conflicts occur only
324 * when the total seeding is longer than the random
326 state[st_idx++]^=local_md[k];
327 if (st_idx >= STATE_SIZE)
332 if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND);
333 /* Don't just copy back local_md into md -- this could mean that
334 * other thread's seeding remains without effect (except for
335 * the incremented counter). By XORing it we keep at least as
336 * much entropy as fits into md. */
337 for (k = 0; k < (int)sizeof(md); k++)
339 md[k] ^= local_md[k];
341 if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */
343 if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
345 #if !defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32)
346 assert(md_c[1] == md_count[1]);
350 EVP_MD_CTX_cleanup(&m);
354 static int ssleay_rand_seed(const void *buf, int num)
356 return ssleay_rand_add(buf, num, (double)num);
359 static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo)
361 static volatile int stirred_pool = 0;
362 int i,j,k,st_num,st_idx;
366 unsigned char local_md[MD_DIGEST_LENGTH];
368 #ifndef GETPID_IS_MEANINGLESS
369 pid_t curr_pid = getpid();
371 time_t curr_time = time(NULL);
372 int do_stir_pool = 0;
373 /* time value for various platforms */
374 #ifdef OPENSSL_SYS_WIN32
379 SystemTimeToFileTime(&t, &tv);
381 GetSystemTimeAsFileTime(&tv);
383 #elif defined(OPENSSL_SYS_VXWORKS)
385 clock_gettime(CLOCK_REALTIME, &ts);
386 #elif defined(OPENSSL_SYSNAME_DSPBIOS)
387 unsigned long long tv, OPENSSL_rdtsc();
388 tv = OPENSSL_rdtsc();
391 gettimeofday(&tv, NULL);
395 if (rand_predictable)
397 static unsigned char val=0;
399 for (i=0; i<num; i++)
409 /* round upwards to multiple of MD_DIGEST_LENGTH/2 */
410 num_ceil = (1 + (num-1)/(MD_DIGEST_LENGTH/2)) * (MD_DIGEST_LENGTH/2);
413 * (Based on the rand(3) manpage:)
415 * For each group of 10 bytes (or less), we do the following:
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'.
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
430 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
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;
447 ok = (entropy >= ENTROPY_NEEDED);
450 /* If the PRNG state is not yet unpredictable, then seeing
451 * the PRNG output may help attackers to determine the new
452 * state; thus we have to decrease the entropy estimate.
453 * Once we've had enough initial seeding we don't bother to
454 * adjust the entropy count, though, because we're not ambitious
455 * to provide *information-theoretic* randomness.
457 * NOTE: This approach fails if the program forks before
458 * we have enough entropy. Entropy should be collected
459 * in a separate input pool and be transferred to the
460 * output pool only when the entropy limit has been reached.
469 /* In the output function only half of 'md' remains secret,
470 * so we better make sure that the required entropy gets
471 * 'evenly distributed' through 'state', our randomness pool.
472 * The input function (ssleay_rand_add) chains all of 'md',
473 * which makes it more suitable for this purpose.
476 int n = STATE_SIZE; /* so that the complete pool gets accessed */
479 #if MD_DIGEST_LENGTH > 20
480 # error "Please adjust DUMMY_SEED."
482 #define DUMMY_SEED "...................." /* at least MD_DIGEST_LENGTH */
483 /* Note that the seed does not matter, it's just that
484 * ssleay_rand_add expects to have something to hash. */
485 ssleay_rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0);
486 n -= MD_DIGEST_LENGTH;
494 md_c[0] = md_count[0];
495 md_c[1] = md_count[1];
496 memcpy(local_md, md, sizeof md);
498 state_index+=num_ceil;
499 if (state_index > state_num)
500 state_index %= state_num;
502 /* state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num]
503 * are now ours (but other threads may use them too) */
507 /* before unlocking, we must clear 'crypto_lock_rand' */
508 crypto_lock_rand = 0;
509 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
513 /* num_ceil -= MD_DIGEST_LENGTH/2 */
514 j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num;
518 #ifndef GETPID_IS_MEANINGLESS
519 if (curr_pid) /* just in the first iteration to save time */
521 if (!MD_Update(&m,(unsigned char*)&curr_pid,
527 if (curr_time) /* just in the first iteration to save time */
529 if (!MD_Update(&m,(unsigned char*)&curr_time,
532 if (!MD_Update(&m,(unsigned char*)&tv,
538 if (!MD_Update(&m,local_md,MD_DIGEST_LENGTH))
540 if (!MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)))
543 #ifndef PURIFY /* purify complains */
544 /* The following line uses the supplied buffer as a small
545 * source of entropy: since this buffer is often uninitialised
546 * it may cause programs such as purify or valgrind to
547 * complain. So for those builds it is not used: the removal
548 * of such a small source of entropy has negligible impact on
551 if (!MD_Update(&m,buf,j))
555 k=(st_idx+MD_DIGEST_LENGTH/2)-st_num;
558 if (!MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2-k))
560 if (!MD_Update(&m,&(state[0]),k))
564 if (!MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2))
566 if (!MD_Final(&m,local_md))
569 for (i=0; i<MD_DIGEST_LENGTH/2; i++)
571 state[st_idx++]^=local_md[i]; /* may compete with other threads */
572 if (st_idx >= st_num)
575 *(buf++)=local_md[i+MD_DIGEST_LENGTH/2];
580 || !MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c))
581 || !MD_Update(&m,local_md,MD_DIGEST_LENGTH))
583 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
584 if (!MD_Update(&m,md,MD_DIGEST_LENGTH) || !MD_Final(&m,md))
586 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
589 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
591 EVP_MD_CTX_cleanup(&m);
598 RANDerr(RAND_F_SSLEAY_RAND_BYTES,RAND_R_PRNG_NOT_SEEDED);
599 ERR_add_error_data(1, "You need to read the OpenSSL FAQ, "
600 "http://www.openssl.org/support/faq.html");
604 EVP_MD_CTX_cleanup(&m);
605 RANDerr(RAND_F_SSLEAY_RAND_BYTES,ERR_R_EVP_LIB);
610 static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num)
612 return ssleay_rand_bytes(buf, num, 0);
615 /* pseudo-random bytes that are guaranteed to be unique but not
617 static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num)
619 return ssleay_rand_bytes(buf, num, 1);
622 static int ssleay_rand_status(void)
628 CRYPTO_THREADID_current(&cur);
629 /* check if we already have the lock
630 * (could happen if a RAND_poll() implementation calls RAND_status()) */
631 if (crypto_lock_rand)
633 CRYPTO_r_lock(CRYPTO_LOCK_RAND2);
634 do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur);
635 CRYPTO_r_unlock(CRYPTO_LOCK_RAND2);
642 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
644 /* prevent ssleay_rand_bytes() from trying to obtain the lock again */
645 CRYPTO_w_lock(CRYPTO_LOCK_RAND2);
646 CRYPTO_THREADID_cpy(&locking_threadid, &cur);
647 CRYPTO_w_unlock(CRYPTO_LOCK_RAND2);
648 crypto_lock_rand = 1;
657 ret = entropy >= ENTROPY_NEEDED;
661 /* before unlocking, we must clear 'crypto_lock_rand' */
662 crypto_lock_rand = 0;
664 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
670 /* rand_hw_seed: get seed data from any available hardware RNG.
671 * only currently supports rdrand.
674 /* Adapted from eng_rdrand.c */
676 #if (defined(__i386) || defined(__i386__) || defined(_M_IX86) || \
677 defined(__x86_64) || defined(__x86_64__) || \
678 defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ)
680 #define RDRAND_CALLS 4
682 size_t OPENSSL_ia32_rdrand(void);
683 extern unsigned int OPENSSL_ia32cap_P[];
685 static void rand_hw_seed(EVP_MD_CTX *ctx)
688 if (!(OPENSSL_ia32cap_P[1] & (1<<(62-32))))
690 for (i = 0; i < RDRAND_CALLS; i++)
693 rnd = OPENSSL_ia32_rdrand();
696 MD_Update(ctx, (unsigned char *)rnd, sizeof(size_t));
700 /* XOR an existing buffer with random data */
702 void rand_hw_xor(unsigned char *buf, size_t num)
705 if (!(OPENSSL_ia32cap_P[1] & (1<<(62-32))))
707 while (num >= sizeof(size_t))
709 rnd = OPENSSL_ia32_rdrand();
712 *((size_t *)buf) ^= rnd;
713 buf += sizeof(size_t);
714 num -= sizeof(size_t);
718 rnd = OPENSSL_ia32_rdrand();
734 static void rand_hw_seed(EVP_MD_CTX *ctx)
739 void rand_hw_xor(unsigned char *buf, size_t num)