2 * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include <openssl/crypto.h>
12 #include <openssl/err.h>
13 #include <openssl/rand.h>
15 #include "internal/thread_once.h"
16 #include "internal/rand_int.h"
17 #include "internal/cryptlib_int.h"
20 * Support framework for NIST SP 800-90A DRBG
22 * See manual page RAND_DRBG(7) for a general overview.
24 * The OpenSSL model is to have new and free functions, and that new
25 * does all initialization. That is not the NIST model, which has
26 * instantiation and un-instantiate, and re-use within a new/free
27 * lifecycle. (No doubt this comes from the desire to support hardware
28 * DRBG, where allocation of resources on something like an HSM is
29 * a much bigger deal than just re-setting an allocated resource.)
33 * The three shared DRBG instances
35 * There are three shared DRBG instances: <master>, <public>, and <private>.
41 * Not used directly by the application, only for reseeding the two other
42 * DRBGs. It reseeds itself by pulling either randomness from os entropy
43 * sources or by consuming randomness which was added by RAND_add().
45 * The <master> DRBG is a global instance which is accessed concurrently by
46 * all threads. The necessary locking is managed automatically by its child
47 * DRBG instances during reseeding.
49 static RAND_DRBG
*master_drbg
;
53 * Used by default for generating random bytes using RAND_bytes().
55 * The <public> DRBG is thread-local, i.e., there is one instance per thread.
57 static CRYPTO_THREAD_LOCAL public_drbg
;
61 * Used by default for generating private keys using RAND_priv_bytes()
63 * The <private> DRBG is thread-local, i.e., there is one instance per thread.
65 static CRYPTO_THREAD_LOCAL private_drbg
;
69 /* NIST SP 800-90A DRBG recommends the use of a personalization string. */
70 static const char ossl_pers_string
[] = "OpenSSL NIST SP 800-90A DRBG";
72 static CRYPTO_ONCE rand_drbg_init
= CRYPTO_ONCE_STATIC_INIT
;
76 static int rand_drbg_type
= RAND_DRBG_TYPE
;
77 static unsigned int rand_drbg_flags
= RAND_DRBG_FLAGS
;
79 static unsigned int master_reseed_interval
= MASTER_RESEED_INTERVAL
;
80 static unsigned int slave_reseed_interval
= SLAVE_RESEED_INTERVAL
;
82 static time_t master_reseed_time_interval
= MASTER_RESEED_TIME_INTERVAL
;
83 static time_t slave_reseed_time_interval
= SLAVE_RESEED_TIME_INTERVAL
;
85 static RAND_DRBG
*drbg_setup(RAND_DRBG
*parent
);
87 static RAND_DRBG
*rand_drbg_new(int secure
,
93 * Set/initialize |drbg| to be of type |type|, with optional |flags|.
95 * If |type| and |flags| are zero, use the defaults
97 * Returns 1 on success, 0 on failure.
99 int RAND_DRBG_set(RAND_DRBG
*drbg
, int type
, unsigned int flags
)
103 if (type
== 0 && flags
== 0) {
104 type
= rand_drbg_type
;
105 flags
= rand_drbg_flags
;
108 drbg
->state
= DRBG_UNINITIALISED
;
114 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
117 /* Uninitialized; that's okay. */
119 case NID_aes_128_ctr
:
120 case NID_aes_192_ctr
:
121 case NID_aes_256_ctr
:
122 ret
= drbg_ctr_init(drbg
);
127 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_ERROR_INITIALISING_DRBG
);
132 * Set/initialize default |type| and |flag| for new drbg instances.
134 * Returns 1 on success, 0 on failure.
136 int RAND_DRBG_set_defaults(int type
, unsigned int flags
)
142 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
144 case NID_aes_128_ctr
:
145 case NID_aes_192_ctr
:
146 case NID_aes_256_ctr
:
150 if ((flags
& ~RAND_DRBG_USED_FLAGS
) != 0) {
151 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS
, RAND_R_UNSUPPORTED_DRBG_FLAGS
);
155 rand_drbg_type
= type
;
156 rand_drbg_flags
= flags
;
163 * Allocate memory and initialize a new DRBG. The DRBG is allocated on
164 * the secure heap if |secure| is nonzero and the secure heap is enabled.
165 * The |parent|, if not NULL, will be used as random source for reseeding.
167 * Returns a pointer to the new DRBG instance on success, NULL on failure.
169 static RAND_DRBG
*rand_drbg_new(int secure
,
174 RAND_DRBG
*drbg
= secure
?
175 OPENSSL_secure_zalloc(sizeof(*drbg
)) : OPENSSL_zalloc(sizeof(*drbg
));
178 RANDerr(RAND_F_RAND_DRBG_NEW
, ERR_R_MALLOC_FAILURE
);
182 drbg
->secure
= secure
&& CRYPTO_secure_allocated(drbg
);
183 drbg
->fork_count
= rand_fork_count
;
184 drbg
->parent
= parent
;
186 if (parent
== NULL
) {
187 drbg
->get_entropy
= rand_drbg_get_entropy
;
188 drbg
->cleanup_entropy
= rand_drbg_cleanup_entropy
;
189 #ifndef RAND_DRBG_GET_RANDOM_NONCE
190 drbg
->get_nonce
= rand_drbg_get_nonce
;
191 drbg
->cleanup_nonce
= rand_drbg_cleanup_nonce
;
194 drbg
->reseed_interval
= master_reseed_interval
;
195 drbg
->reseed_time_interval
= master_reseed_time_interval
;
197 drbg
->get_entropy
= rand_drbg_get_entropy
;
198 drbg
->cleanup_entropy
= rand_drbg_cleanup_entropy
;
200 * Do not provide nonce callbacks, the child DRBGs will
201 * obtain their nonce using random bits from the parent.
204 drbg
->reseed_interval
= slave_reseed_interval
;
205 drbg
->reseed_time_interval
= slave_reseed_time_interval
;
208 if (RAND_DRBG_set(drbg
, type
, flags
) == 0)
211 if (parent
!= NULL
) {
212 rand_drbg_lock(parent
);
213 if (drbg
->strength
> parent
->strength
) {
215 * We currently don't support the algorithm from NIST SP 800-90C
216 * 10.1.2 to use a weaker DRBG as source
218 rand_drbg_unlock(parent
);
219 RANDerr(RAND_F_RAND_DRBG_NEW
, RAND_R_PARENT_STRENGTH_TOO_WEAK
);
222 rand_drbg_unlock(parent
);
229 OPENSSL_secure_free(drbg
);
236 RAND_DRBG
*RAND_DRBG_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
238 return rand_drbg_new(0, type
, flags
, parent
);
241 RAND_DRBG
*RAND_DRBG_secure_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
243 return rand_drbg_new(1, type
, flags
, parent
);
247 * Uninstantiate |drbg| and free all memory.
249 void RAND_DRBG_free(RAND_DRBG
*drbg
)
254 if (drbg
->meth
!= NULL
)
255 drbg
->meth
->uninstantiate(drbg
);
256 CRYPTO_THREAD_lock_free(drbg
->lock
);
257 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG
, drbg
, &drbg
->ex_data
);
260 OPENSSL_secure_clear_free(drbg
, sizeof(*drbg
));
262 OPENSSL_clear_free(drbg
, sizeof(*drbg
));
266 * Instantiate |drbg|, after it has been initialized. Use |pers| and
267 * |perslen| as prediction-resistance input.
269 * Requires that drbg->lock is already locked for write, if non-null.
271 * Returns 1 on success, 0 on failure.
273 int RAND_DRBG_instantiate(RAND_DRBG
*drbg
,
274 const unsigned char *pers
, size_t perslen
)
276 unsigned char *nonce
= NULL
, *entropy
= NULL
;
277 size_t noncelen
= 0, entropylen
= 0;
278 size_t min_entropy
= drbg
->strength
;
279 size_t min_entropylen
= drbg
->min_entropylen
;
280 size_t max_entropylen
= drbg
->max_entropylen
;
282 if (perslen
> drbg
->max_perslen
) {
283 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
284 RAND_R_PERSONALISATION_STRING_TOO_LONG
);
288 if (drbg
->meth
== NULL
)
290 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
291 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
295 if (drbg
->state
!= DRBG_UNINITIALISED
) {
296 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
297 drbg
->state
== DRBG_ERROR
? RAND_R_IN_ERROR_STATE
298 : RAND_R_ALREADY_INSTANTIATED
);
302 drbg
->state
= DRBG_ERROR
;
305 * NIST SP800-90Ar1 section 9.1 says you can combine getting the entropy
306 * and nonce in 1 call by increasing the entropy with 50% and increasing
307 * the minimum length to accomadate the length of the nonce.
308 * We do this in case a nonce is require and get_nonce is NULL.
310 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
== NULL
) {
311 min_entropy
+= drbg
->strength
/ 2;
312 min_entropylen
+= drbg
->min_noncelen
;
313 max_entropylen
+= drbg
->max_noncelen
;
316 if (drbg
->get_entropy
!= NULL
)
317 entropylen
= drbg
->get_entropy(drbg
, &entropy
, min_entropy
,
318 min_entropylen
, max_entropylen
, 0);
319 if (entropylen
< min_entropylen
320 || entropylen
> max_entropylen
) {
321 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
325 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
!= NULL
) {
326 noncelen
= drbg
->get_nonce(drbg
, &nonce
, drbg
->strength
/ 2,
327 drbg
->min_noncelen
, drbg
->max_noncelen
);
328 if (noncelen
< drbg
->min_noncelen
|| noncelen
> drbg
->max_noncelen
) {
329 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_NONCE
);
334 if (!drbg
->meth
->instantiate(drbg
, entropy
, entropylen
,
335 nonce
, noncelen
, pers
, perslen
)) {
336 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_INSTANTIATING_DRBG
);
340 drbg
->state
= DRBG_READY
;
341 drbg
->generate_counter
= 0;
342 drbg
->reseed_time
= time(NULL
);
343 if (drbg
->reseed_counter
> 0) {
344 if (drbg
->parent
== NULL
)
345 drbg
->reseed_counter
++;
347 drbg
->reseed_counter
= drbg
->parent
->reseed_counter
;
351 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
352 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
353 if (nonce
!= NULL
&& drbg
->cleanup_nonce
!= NULL
)
354 drbg
->cleanup_nonce(drbg
, nonce
, noncelen
);
355 if (drbg
->pool
!= NULL
) {
356 if (drbg
->state
== DRBG_READY
) {
357 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
358 RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED
);
359 drbg
->state
= DRBG_ERROR
;
361 rand_pool_free(drbg
->pool
);
364 if (drbg
->state
== DRBG_READY
)
370 * Uninstantiate |drbg|. Must be instantiated before it can be used.
372 * Requires that drbg->lock is already locked for write, if non-null.
374 * Returns 1 on success, 0 on failure.
376 int RAND_DRBG_uninstantiate(RAND_DRBG
*drbg
)
378 if (drbg
->meth
== NULL
)
380 RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE
,
381 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
385 /* Clear the entire drbg->ctr struct, then reset some important
386 * members of the drbg->ctr struct (e.g. keysize, df_ks) to their
389 drbg
->meth
->uninstantiate(drbg
);
390 return RAND_DRBG_set(drbg
, drbg
->type
, drbg
->flags
);
394 * Reseed |drbg|, mixing in the specified data
396 * Requires that drbg->lock is already locked for write, if non-null.
398 * Returns 1 on success, 0 on failure.
400 int RAND_DRBG_reseed(RAND_DRBG
*drbg
,
401 const unsigned char *adin
, size_t adinlen
,
402 int prediction_resistance
)
404 unsigned char *entropy
= NULL
;
405 size_t entropylen
= 0;
407 if (drbg
->state
== DRBG_ERROR
) {
408 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_IN_ERROR_STATE
);
411 if (drbg
->state
== DRBG_UNINITIALISED
) {
412 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_NOT_INSTANTIATED
);
418 else if (adinlen
> drbg
->max_adinlen
) {
419 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
423 drbg
->state
= DRBG_ERROR
;
424 if (drbg
->get_entropy
!= NULL
)
425 entropylen
= drbg
->get_entropy(drbg
, &entropy
, drbg
->strength
,
426 drbg
->min_entropylen
,
427 drbg
->max_entropylen
,
428 prediction_resistance
);
429 if (entropylen
< drbg
->min_entropylen
430 || entropylen
> drbg
->max_entropylen
) {
431 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
435 if (!drbg
->meth
->reseed(drbg
, entropy
, entropylen
, adin
, adinlen
))
438 drbg
->state
= DRBG_READY
;
439 drbg
->generate_counter
= 0;
440 drbg
->reseed_time
= time(NULL
);
441 if (drbg
->reseed_counter
> 0) {
442 if (drbg
->parent
== NULL
)
443 drbg
->reseed_counter
++;
445 drbg
->reseed_counter
= drbg
->parent
->reseed_counter
;
449 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
450 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
451 if (drbg
->state
== DRBG_READY
)
457 * Restart |drbg|, using the specified entropy or additional input
459 * Tries its best to get the drbg instantiated by all means,
460 * regardless of its current state.
462 * Optionally, a |buffer| of |len| random bytes can be passed,
463 * which is assumed to contain at least |entropy| bits of entropy.
465 * If |entropy| > 0, the buffer content is used as entropy input.
467 * If |entropy| == 0, the buffer content is used as additional input
469 * Returns 1 on success, 0 on failure.
471 * This function is used internally only.
473 int rand_drbg_restart(RAND_DRBG
*drbg
,
474 const unsigned char *buffer
, size_t len
, size_t entropy
)
477 const unsigned char *adin
= NULL
;
480 if (drbg
->pool
!= NULL
) {
481 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
482 rand_pool_free(drbg
->pool
);
486 if (buffer
!= NULL
) {
488 if (drbg
->max_entropylen
< len
) {
489 RANDerr(RAND_F_RAND_DRBG_RESTART
,
490 RAND_R_ENTROPY_INPUT_TOO_LONG
);
494 if (entropy
> 8 * len
) {
495 RANDerr(RAND_F_RAND_DRBG_RESTART
, RAND_R_ENTROPY_OUT_OF_RANGE
);
499 /* will be picked up by the rand_drbg_get_entropy() callback */
500 drbg
->pool
= rand_pool_new(entropy
, len
, len
);
501 if (drbg
->pool
== NULL
)
504 rand_pool_add(drbg
->pool
, buffer
, len
, entropy
);
506 if (drbg
->max_adinlen
< len
) {
507 RANDerr(RAND_F_RAND_DRBG_RESTART
,
508 RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
516 /* repair error state */
517 if (drbg
->state
== DRBG_ERROR
)
518 RAND_DRBG_uninstantiate(drbg
);
520 /* repair uninitialized state */
521 if (drbg
->state
== DRBG_UNINITIALISED
) {
522 /* reinstantiate drbg */
523 RAND_DRBG_instantiate(drbg
,
524 (const unsigned char *) ossl_pers_string
,
525 sizeof(ossl_pers_string
) - 1);
526 /* already reseeded. prevent second reseeding below */
527 reseeded
= (drbg
->state
== DRBG_READY
);
530 /* refresh current state if entropy or additional input has been provided */
531 if (drbg
->state
== DRBG_READY
) {
534 * mix in additional input without reseeding
536 * Similar to RAND_DRBG_reseed(), but the provided additional
537 * data |adin| is mixed into the current state without pulling
538 * entropy from the trusted entropy source using get_entropy().
539 * This is not a reseeding in the strict sense of NIST SP 800-90A.
541 drbg
->meth
->reseed(drbg
, adin
, adinlen
, NULL
, 0);
542 } else if (reseeded
== 0) {
543 /* do a full reseeding if it has not been done yet above */
544 RAND_DRBG_reseed(drbg
, NULL
, 0, 0);
548 /* check whether a given entropy pool was cleared properly during reseed */
549 if (drbg
->pool
!= NULL
) {
550 drbg
->state
= DRBG_ERROR
;
551 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
552 rand_pool_free(drbg
->pool
);
557 return drbg
->state
== DRBG_READY
;
561 * Generate |outlen| bytes into the buffer at |out|. Reseed if we need
562 * to or if |prediction_resistance| is set. Additional input can be
563 * sent in |adin| and |adinlen|.
565 * Requires that drbg->lock is already locked for write, if non-null.
567 * Returns 1 on success, 0 on failure.
570 int RAND_DRBG_generate(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
,
571 int prediction_resistance
,
572 const unsigned char *adin
, size_t adinlen
)
574 int reseed_required
= 0;
576 if (drbg
->state
!= DRBG_READY
) {
577 /* try to recover from previous errors */
578 rand_drbg_restart(drbg
, NULL
, 0, 0);
580 if (drbg
->state
== DRBG_ERROR
) {
581 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_IN_ERROR_STATE
);
584 if (drbg
->state
== DRBG_UNINITIALISED
) {
585 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_NOT_INSTANTIATED
);
590 if (outlen
> drbg
->max_request
) {
591 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG
);
594 if (adinlen
> drbg
->max_adinlen
) {
595 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
599 if (drbg
->fork_count
!= rand_fork_count
) {
600 drbg
->fork_count
= rand_fork_count
;
604 if (drbg
->reseed_interval
> 0) {
605 if (drbg
->generate_counter
>= drbg
->reseed_interval
)
608 if (drbg
->reseed_time_interval
> 0) {
609 time_t now
= time(NULL
);
610 if (now
< drbg
->reseed_time
611 || now
- drbg
->reseed_time
>= drbg
->reseed_time_interval
)
614 if (drbg
->reseed_counter
> 0 && drbg
->parent
!= NULL
) {
615 if (drbg
->reseed_counter
!= drbg
->parent
->reseed_counter
)
619 if (reseed_required
|| prediction_resistance
) {
620 if (!RAND_DRBG_reseed(drbg
, adin
, adinlen
, prediction_resistance
)) {
621 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_RESEED_ERROR
);
628 if (!drbg
->meth
->generate(drbg
, out
, outlen
, adin
, adinlen
)) {
629 drbg
->state
= DRBG_ERROR
;
630 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_GENERATE_ERROR
);
634 drbg
->generate_counter
++;
640 * Generates |outlen| random bytes and stores them in |out|. It will
641 * using the given |drbg| to generate the bytes.
643 * Requires that drbg->lock is already locked for write, if non-null.
645 * Returns 1 on success 0 on failure.
647 int RAND_DRBG_bytes(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
)
649 unsigned char *additional
= NULL
;
650 size_t additional_len
;
654 additional_len
= rand_drbg_get_additional_data(&additional
, drbg
->max_adinlen
);
656 for ( ; outlen
> 0; outlen
-= chunk
, out
+= chunk
) {
658 if (chunk
> drbg
->max_request
)
659 chunk
= drbg
->max_request
;
660 ret
= RAND_DRBG_generate(drbg
, out
, chunk
, 0, additional
, additional_len
);
667 if (additional_len
!= 0)
668 OPENSSL_secure_clear_free(additional
, additional_len
);
674 * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
676 * Setting the callbacks is allowed only if the drbg has not been
677 * initialized yet. Otherwise, the operation will fail.
679 * Returns 1 on success, 0 on failure.
681 int RAND_DRBG_set_callbacks(RAND_DRBG
*drbg
,
682 RAND_DRBG_get_entropy_fn get_entropy
,
683 RAND_DRBG_cleanup_entropy_fn cleanup_entropy
,
684 RAND_DRBG_get_nonce_fn get_nonce
,
685 RAND_DRBG_cleanup_nonce_fn cleanup_nonce
)
687 if (drbg
->state
!= DRBG_UNINITIALISED
)
689 drbg
->get_entropy
= get_entropy
;
690 drbg
->cleanup_entropy
= cleanup_entropy
;
691 drbg
->get_nonce
= get_nonce
;
692 drbg
->cleanup_nonce
= cleanup_nonce
;
697 * Set the reseed interval.
699 * The drbg will reseed automatically whenever the number of generate
700 * requests exceeds the given reseed interval. If the reseed interval
701 * is 0, then this feature is disabled.
703 * Returns 1 on success, 0 on failure.
705 int RAND_DRBG_set_reseed_interval(RAND_DRBG
*drbg
, unsigned int interval
)
707 if (interval
> MAX_RESEED_INTERVAL
)
709 drbg
->reseed_interval
= interval
;
714 * Set the reseed time interval.
716 * The drbg will reseed automatically whenever the time elapsed since
717 * the last reseeding exceeds the given reseed time interval. For safety,
718 * a reseeding will also occur if the clock has been reset to a smaller
721 * Returns 1 on success, 0 on failure.
723 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG
*drbg
, time_t interval
)
725 if (interval
> MAX_RESEED_TIME_INTERVAL
)
727 drbg
->reseed_time_interval
= interval
;
732 * Set the default values for reseed (time) intervals of new DRBG instances
734 * The default values can be set independently for master DRBG instances
735 * (without a parent) and slave DRBG instances (with parent).
737 * Returns 1 on success, 0 on failure.
740 int RAND_DRBG_set_reseed_defaults(
741 unsigned int _master_reseed_interval
,
742 unsigned int _slave_reseed_interval
,
743 time_t _master_reseed_time_interval
,
744 time_t _slave_reseed_time_interval
747 if (_master_reseed_interval
> MAX_RESEED_INTERVAL
748 || _slave_reseed_interval
> MAX_RESEED_INTERVAL
)
751 if (_master_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
752 || _slave_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
)
755 master_reseed_interval
= _master_reseed_interval
;
756 slave_reseed_interval
= _slave_reseed_interval
;
758 master_reseed_time_interval
= _master_reseed_time_interval
;
759 slave_reseed_time_interval
= _slave_reseed_time_interval
;
765 * Locks the given drbg. Locking a drbg which does not have locking
766 * enabled is considered a successful no-op.
768 * Returns 1 on success, 0 on failure.
770 int rand_drbg_lock(RAND_DRBG
*drbg
)
772 if (drbg
->lock
!= NULL
)
773 return CRYPTO_THREAD_write_lock(drbg
->lock
);
779 * Unlocks the given drbg. Unlocking a drbg which does not have locking
780 * enabled is considered a successful no-op.
782 * Returns 1 on success, 0 on failure.
784 int rand_drbg_unlock(RAND_DRBG
*drbg
)
786 if (drbg
->lock
!= NULL
)
787 return CRYPTO_THREAD_unlock(drbg
->lock
);
793 * Enables locking for the given drbg
795 * Locking can only be enabled if the random generator
796 * is in the uninitialized state.
798 * Returns 1 on success, 0 on failure.
800 int rand_drbg_enable_locking(RAND_DRBG
*drbg
)
802 if (drbg
->state
!= DRBG_UNINITIALISED
) {
803 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
804 RAND_R_DRBG_ALREADY_INITIALIZED
);
808 if (drbg
->lock
== NULL
) {
809 if (drbg
->parent
!= NULL
&& drbg
->parent
->lock
== NULL
) {
810 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
811 RAND_R_PARENT_LOCKING_NOT_ENABLED
);
815 drbg
->lock
= CRYPTO_THREAD_lock_new();
816 if (drbg
->lock
== NULL
) {
817 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
818 RAND_R_FAILED_TO_CREATE_LOCK
);
827 * Get and set the EXDATA
829 int RAND_DRBG_set_ex_data(RAND_DRBG
*drbg
, int idx
, void *arg
)
831 return CRYPTO_set_ex_data(&drbg
->ex_data
, idx
, arg
);
834 void *RAND_DRBG_get_ex_data(const RAND_DRBG
*drbg
, int idx
)
836 return CRYPTO_get_ex_data(&drbg
->ex_data
, idx
);
841 * The following functions provide a RAND_METHOD that works on the
842 * global DRBG. They lock.
846 * Allocates a new global DRBG on the secure heap (if enabled) and
847 * initializes it with default settings.
849 * Returns a pointer to the new DRBG instance on success, NULL on failure.
851 static RAND_DRBG
*drbg_setup(RAND_DRBG
*parent
)
855 drbg
= RAND_DRBG_secure_new(rand_drbg_type
, rand_drbg_flags
, parent
);
859 /* Only the master DRBG needs to have a lock */
860 if (parent
== NULL
&& rand_drbg_enable_locking(drbg
) == 0)
863 /* enable seed propagation */
864 drbg
->reseed_counter
= 1;
867 * Ignore instantiation error to support just-in-time instantiation.
869 * The state of the drbg will be checked in RAND_DRBG_generate() and
870 * an automatic recovery is attempted.
872 (void)RAND_DRBG_instantiate(drbg
,
873 (const unsigned char *) ossl_pers_string
,
874 sizeof(ossl_pers_string
) - 1);
878 RAND_DRBG_free(drbg
);
883 * Initialize the global DRBGs on first use.
884 * Returns 1 on success, 0 on failure.
886 DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init
)
891 * ensure that libcrypto is initialized, otherwise the
892 * DRBG locks are not cleaned up properly
894 if (!OPENSSL_init_crypto(0, NULL
))
897 ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND
);
899 master_drbg
= drbg_setup(NULL
);
901 ret
&= CRYPTO_THREAD_init_local(&private_drbg
, NULL
);
902 ret
&= CRYPTO_THREAD_init_local(&public_drbg
, NULL
);
904 if (master_drbg
== NULL
|| ret
== 0)
910 /* Clean up the global DRBGs before exit */
911 void rand_drbg_cleanup_int(void)
913 RAND_DRBG_free(master_drbg
);
916 CRYPTO_THREAD_cleanup_local(&private_drbg
);
917 CRYPTO_THREAD_cleanup_local(&public_drbg
);
920 void drbg_delete_thread_state()
924 drbg
= CRYPTO_THREAD_get_local(&public_drbg
);
925 RAND_DRBG_free(drbg
);
927 drbg
= CRYPTO_THREAD_get_local(&private_drbg
);
928 RAND_DRBG_free(drbg
);
931 /* Implements the default OpenSSL RAND_bytes() method */
932 static int drbg_bytes(unsigned char *out
, int count
)
935 RAND_DRBG
*drbg
= RAND_DRBG_get0_public();
940 ret
= RAND_DRBG_bytes(drbg
, out
, count
);
945 /* Implements the default OpenSSL RAND_add() method */
946 static int drbg_add(const void *buf
, int num
, double randomness
)
949 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
954 if (num
< 0 || randomness
< 0.0)
957 if (randomness
> (double)drbg
->max_entropylen
) {
959 * The purpose of this check is to bound |randomness| by a
960 * relatively small value in order to prevent an integer
961 * overflow when multiplying by 8 in the rand_drbg_restart()
967 rand_drbg_lock(drbg
);
968 ret
= rand_drbg_restart(drbg
, buf
,
969 (size_t)(unsigned int)num
,
970 (size_t)(8*randomness
));
971 rand_drbg_unlock(drbg
);
976 /* Implements the default OpenSSL RAND_seed() method */
977 static int drbg_seed(const void *buf
, int num
)
979 return drbg_add(buf
, num
, num
);
982 /* Implements the default OpenSSL RAND_status() method */
983 static int drbg_status(void)
986 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
991 rand_drbg_lock(drbg
);
992 ret
= drbg
->state
== DRBG_READY
? 1 : 0;
993 rand_drbg_unlock(drbg
);
998 * Get the master DRBG.
999 * Returns pointer to the DRBG on success, NULL on failure.
1002 RAND_DRBG
*RAND_DRBG_get0_master(void)
1004 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
1011 * Get the public DRBG.
1012 * Returns pointer to the DRBG on success, NULL on failure.
1014 RAND_DRBG
*RAND_DRBG_get0_public(void)
1018 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
1021 drbg
= CRYPTO_THREAD_get_local(&public_drbg
);
1023 ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND
);
1024 drbg
= drbg_setup(master_drbg
);
1025 CRYPTO_THREAD_set_local(&public_drbg
, drbg
);
1031 * Get the private DRBG.
1032 * Returns pointer to the DRBG on success, NULL on failure.
1034 RAND_DRBG
*RAND_DRBG_get0_private(void)
1038 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
1041 drbg
= CRYPTO_THREAD_get_local(&private_drbg
);
1043 ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND
);
1044 drbg
= drbg_setup(master_drbg
);
1045 CRYPTO_THREAD_set_local(&private_drbg
, drbg
);
1050 RAND_METHOD rand_meth
= {
1059 RAND_METHOD
*RAND_OpenSSL(void)