2 * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (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 typedef struct drbg_global_st
{
35 * The three shared DRBG instances
37 * There are three shared DRBG instances: <master>, <public>, and <private>.
43 * Not used directly by the application, only for reseeding the two other
44 * DRBGs. It reseeds itself by pulling either randomness from os entropy
45 * sources or by consuming randomness which was added by RAND_add().
47 * The <master> DRBG is a global instance which is accessed concurrently by
48 * all threads. The necessary locking is managed automatically by its child
49 * DRBG instances during reseeding.
51 RAND_DRBG
*master_drbg
;
55 * Used by default for generating random bytes using RAND_bytes().
57 * The <public> DRBG is thread-local, i.e., there is one instance per
60 CRYPTO_THREAD_LOCAL public_drbg
;
64 * Used by default for generating private keys using RAND_priv_bytes()
66 * The <private> DRBG is thread-local, i.e., there is one instance per
69 CRYPTO_THREAD_LOCAL private_drbg
;
72 typedef struct drbg_nonce_global_st
{
73 CRYPTO_RWLOCK
*rand_nonce_lock
;
77 /* NIST SP 800-90A DRBG recommends the use of a personalization string. */
78 static const char ossl_pers_string
[] = DRBG_DEFAULT_PERS_STRING
;
80 #define RAND_DRBG_TYPE_FLAGS ( \
81 RAND_DRBG_FLAG_MASTER | RAND_DRBG_FLAG_PUBLIC | RAND_DRBG_FLAG_PRIVATE )
83 #define RAND_DRBG_TYPE_MASTER 0
84 #define RAND_DRBG_TYPE_PUBLIC 1
85 #define RAND_DRBG_TYPE_PRIVATE 2
88 static int rand_drbg_type
[3] = {
89 RAND_DRBG_TYPE
, /* Master */
90 RAND_DRBG_TYPE
, /* Public */
91 RAND_DRBG_TYPE
/* Private */
93 static unsigned int rand_drbg_flags
[3] = {
94 RAND_DRBG_FLAGS
| RAND_DRBG_FLAG_MASTER
, /* Master */
95 RAND_DRBG_FLAGS
| RAND_DRBG_FLAG_PUBLIC
, /* Public */
96 RAND_DRBG_FLAGS
| RAND_DRBG_FLAG_PRIVATE
/* Private */
99 static unsigned int master_reseed_interval
= MASTER_RESEED_INTERVAL
;
100 static unsigned int slave_reseed_interval
= SLAVE_RESEED_INTERVAL
;
102 static time_t master_reseed_time_interval
= MASTER_RESEED_TIME_INTERVAL
;
103 static time_t slave_reseed_time_interval
= SLAVE_RESEED_TIME_INTERVAL
;
105 /* A logical OR of all used DRBG flag bits (currently there is only one) */
106 static const unsigned int rand_drbg_used_flags
=
107 RAND_DRBG_FLAG_CTR_NO_DF
| RAND_DRBG_FLAG_HMAC
| RAND_DRBG_TYPE_FLAGS
;
110 static RAND_DRBG
*drbg_setup(OPENSSL_CTX
*ctx
, RAND_DRBG
*parent
, int drbg_type
);
112 static RAND_DRBG
*rand_drbg_new(OPENSSL_CTX
*ctx
,
118 static int is_ctr(int type
)
121 case NID_aes_128_ctr
:
122 case NID_aes_192_ctr
:
123 case NID_aes_256_ctr
:
130 static int is_digest(int type
)
151 * Initialize the OPENSSL_CTX global DRBGs on first use.
152 * Returns the allocated global data on success or NULL on failure.
154 static void *drbg_ossl_ctx_new(OPENSSL_CTX
*libctx
)
156 DRBG_GLOBAL
*dgbl
= OPENSSL_zalloc(sizeof(*dgbl
));
161 if (!CRYPTO_THREAD_init_local(&dgbl
->private_drbg
, NULL
))
164 if (!CRYPTO_THREAD_init_local(&dgbl
->public_drbg
, NULL
))
167 dgbl
->master_drbg
= drbg_setup(libctx
, NULL
, RAND_DRBG_TYPE_MASTER
);
168 if (dgbl
->master_drbg
== NULL
)
174 CRYPTO_THREAD_cleanup_local(&dgbl
->public_drbg
);
176 CRYPTO_THREAD_cleanup_local(&dgbl
->private_drbg
);
182 static void drbg_ossl_ctx_free(void *vdgbl
)
184 DRBG_GLOBAL
*dgbl
= vdgbl
;
186 RAND_DRBG_free(dgbl
->master_drbg
);
187 CRYPTO_THREAD_cleanup_local(&dgbl
->private_drbg
);
188 CRYPTO_THREAD_cleanup_local(&dgbl
->public_drbg
);
193 static const OPENSSL_CTX_METHOD drbg_ossl_ctx_method
= {
199 * drbg_ossl_ctx_new() calls drgb_setup() which calls rand_drbg_get_nonce()
200 * which needs to get the rand_nonce_lock out of the OPENSSL_CTX...but since
201 * drbg_ossl_ctx_new() hasn't finished running yet we need the rand_nonce_lock
202 * to be in a different global data object. Otherwise we will go into an
203 * infinite recursion loop.
205 static void *drbg_nonce_ossl_ctx_new(OPENSSL_CTX
*libctx
)
207 DRBG_NONCE_GLOBAL
*dngbl
= OPENSSL_zalloc(sizeof(*dngbl
));
212 dngbl
->rand_nonce_lock
= CRYPTO_THREAD_lock_new();
213 if (dngbl
->rand_nonce_lock
== NULL
) {
221 static void drbg_nonce_ossl_ctx_free(void *vdngbl
)
223 DRBG_NONCE_GLOBAL
*dngbl
= vdngbl
;
225 CRYPTO_THREAD_lock_free(dngbl
->rand_nonce_lock
);
230 static const OPENSSL_CTX_METHOD drbg_nonce_ossl_ctx_method
= {
231 drbg_nonce_ossl_ctx_new
,
232 drbg_nonce_ossl_ctx_free
,
235 static DRBG_GLOBAL
*drbg_get_global(OPENSSL_CTX
*libctx
)
237 return openssl_ctx_get_data(libctx
, OPENSSL_CTX_DRBG_INDEX
,
238 &drbg_ossl_ctx_method
);
241 /* Implements the get_nonce() callback (see RAND_DRBG_set_callbacks()) */
242 size_t rand_drbg_get_nonce(RAND_DRBG
*drbg
,
243 unsigned char **pout
,
244 int entropy
, size_t min_len
, size_t max_len
)
248 DRBG_NONCE_GLOBAL
*dngbl
249 = openssl_ctx_get_data(drbg
->libctx
, OPENSSL_CTX_DRBG_NONCE_INDEX
,
250 &drbg_nonce_ossl_ctx_method
);
259 memset(&data
, 0, sizeof(data
));
260 pool
= rand_pool_new(0, min_len
, max_len
);
264 if (rand_pool_add_nonce_data(pool
) == 0)
267 data
.instance
= drbg
;
268 CRYPTO_atomic_add(&dngbl
->rand_nonce_count
, 1, &data
.count
,
269 dngbl
->rand_nonce_lock
);
271 if (rand_pool_add(pool
, (unsigned char *)&data
, sizeof(data
), 0) == 0)
274 ret
= rand_pool_length(pool
);
275 *pout
= rand_pool_detach(pool
);
278 rand_pool_free(pool
);
284 * Implements the cleanup_nonce() callback (see RAND_DRBG_set_callbacks())
287 void rand_drbg_cleanup_nonce(RAND_DRBG
*drbg
,
288 unsigned char *out
, size_t outlen
)
290 OPENSSL_secure_clear_free(out
, outlen
);
294 * Set/initialize |drbg| to be of type |type|, with optional |flags|.
296 * If |type| and |flags| are zero, use the defaults
298 * Returns 1 on success, 0 on failure.
300 int RAND_DRBG_set(RAND_DRBG
*drbg
, int type
, unsigned int flags
)
304 if (type
== 0 && flags
== 0) {
305 type
= rand_drbg_type
[RAND_DRBG_TYPE_MASTER
];
306 flags
= rand_drbg_flags
[RAND_DRBG_TYPE_MASTER
];
309 /* If set is called multiple times - clear the old one */
310 if (drbg
->type
!= 0 && (type
!= drbg
->type
|| flags
!= drbg
->flags
)) {
311 drbg
->meth
->uninstantiate(drbg
);
312 rand_pool_free(drbg
->adin_pool
);
313 drbg
->adin_pool
= NULL
;
316 drbg
->state
= DRBG_UNINITIALISED
;
321 /* Uninitialized; that's okay. */
324 } else if (is_ctr(type
)) {
325 ret
= drbg_ctr_init(drbg
);
326 } else if (is_digest(type
)) {
327 if (flags
& RAND_DRBG_FLAG_HMAC
)
328 ret
= drbg_hmac_init(drbg
);
330 ret
= drbg_hash_init(drbg
);
335 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
340 drbg
->state
= DRBG_ERROR
;
341 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_ERROR_INITIALISING_DRBG
);
347 * Set/initialize default |type| and |flag| for new drbg instances.
349 * Returns 1 on success, 0 on failure.
351 int RAND_DRBG_set_defaults(int type
, unsigned int flags
)
354 if (!(is_digest(type
) || is_ctr(type
))) {
355 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
359 if ((flags
& ~rand_drbg_used_flags
) != 0) {
360 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS
, RAND_R_UNSUPPORTED_DRBG_FLAGS
);
364 all
= ((flags
& RAND_DRBG_TYPE_FLAGS
) == 0);
365 if (all
|| (flags
& RAND_DRBG_FLAG_MASTER
) != 0) {
366 rand_drbg_type
[RAND_DRBG_TYPE_MASTER
] = type
;
367 rand_drbg_flags
[RAND_DRBG_TYPE_MASTER
] = flags
| RAND_DRBG_FLAG_MASTER
;
369 if (all
|| (flags
& RAND_DRBG_FLAG_PUBLIC
) != 0) {
370 rand_drbg_type
[RAND_DRBG_TYPE_PUBLIC
] = type
;
371 rand_drbg_flags
[RAND_DRBG_TYPE_PUBLIC
] = flags
| RAND_DRBG_FLAG_PUBLIC
;
373 if (all
|| (flags
& RAND_DRBG_FLAG_PRIVATE
) != 0) {
374 rand_drbg_type
[RAND_DRBG_TYPE_PRIVATE
] = type
;
375 rand_drbg_flags
[RAND_DRBG_TYPE_PRIVATE
] = flags
| RAND_DRBG_FLAG_PRIVATE
;
382 * Allocate memory and initialize a new DRBG. The DRBG is allocated on
383 * the secure heap if |secure| is nonzero and the secure heap is enabled.
384 * The |parent|, if not NULL, will be used as random source for reseeding.
386 * Returns a pointer to the new DRBG instance on success, NULL on failure.
388 static RAND_DRBG
*rand_drbg_new(OPENSSL_CTX
*ctx
,
394 RAND_DRBG
*drbg
= secure
? OPENSSL_secure_zalloc(sizeof(*drbg
))
395 : OPENSSL_zalloc(sizeof(*drbg
));
398 RANDerr(RAND_F_RAND_DRBG_NEW
, ERR_R_MALLOC_FAILURE
);
403 drbg
->secure
= secure
&& CRYPTO_secure_allocated(drbg
);
404 drbg
->fork_count
= rand_fork_count
;
405 drbg
->parent
= parent
;
407 if (parent
== NULL
) {
409 drbg
->get_entropy
= rand_crngt_get_entropy
;
410 drbg
->cleanup_entropy
= rand_crngt_cleanup_entropy
;
412 drbg
->get_entropy
= rand_drbg_get_entropy
;
413 drbg
->cleanup_entropy
= rand_drbg_cleanup_entropy
;
415 #ifndef RAND_DRBG_GET_RANDOM_NONCE
416 drbg
->get_nonce
= rand_drbg_get_nonce
;
417 drbg
->cleanup_nonce
= rand_drbg_cleanup_nonce
;
420 drbg
->reseed_interval
= master_reseed_interval
;
421 drbg
->reseed_time_interval
= master_reseed_time_interval
;
423 drbg
->get_entropy
= rand_drbg_get_entropy
;
424 drbg
->cleanup_entropy
= rand_drbg_cleanup_entropy
;
426 * Do not provide nonce callbacks, the child DRBGs will
427 * obtain their nonce using random bits from the parent.
430 drbg
->reseed_interval
= slave_reseed_interval
;
431 drbg
->reseed_time_interval
= slave_reseed_time_interval
;
434 if (RAND_DRBG_set(drbg
, type
, flags
) == 0)
437 if (parent
!= NULL
) {
438 rand_drbg_lock(parent
);
439 if (drbg
->strength
> parent
->strength
) {
441 * We currently don't support the algorithm from NIST SP 800-90C
442 * 10.1.2 to use a weaker DRBG as source
444 rand_drbg_unlock(parent
);
445 RANDerr(RAND_F_RAND_DRBG_NEW
, RAND_R_PARENT_STRENGTH_TOO_WEAK
);
448 rand_drbg_unlock(parent
);
454 RAND_DRBG_free(drbg
);
459 RAND_DRBG
*RAND_DRBG_new_ex(OPENSSL_CTX
*ctx
, int type
, unsigned int flags
,
462 return rand_drbg_new(ctx
, 0, type
, flags
, parent
);
465 RAND_DRBG
*RAND_DRBG_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
467 return RAND_DRBG_new_ex(NULL
, type
, flags
, parent
);
470 RAND_DRBG
*RAND_DRBG_secure_new_ex(OPENSSL_CTX
*ctx
, int type
,
471 unsigned int flags
, RAND_DRBG
*parent
)
473 return rand_drbg_new(ctx
, 1, type
, flags
, parent
);
476 RAND_DRBG
*RAND_DRBG_secure_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
478 return RAND_DRBG_secure_new_ex(NULL
, type
, flags
, parent
);
481 * Uninstantiate |drbg| and free all memory.
483 void RAND_DRBG_free(RAND_DRBG
*drbg
)
488 if (drbg
->meth
!= NULL
)
489 drbg
->meth
->uninstantiate(drbg
);
490 rand_pool_free(drbg
->adin_pool
);
491 CRYPTO_THREAD_lock_free(drbg
->lock
);
492 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG
, drbg
, &drbg
->ex_data
);
495 OPENSSL_secure_clear_free(drbg
, sizeof(*drbg
));
497 OPENSSL_clear_free(drbg
, sizeof(*drbg
));
501 * Instantiate |drbg|, after it has been initialized. Use |pers| and
502 * |perslen| as prediction-resistance input.
504 * Requires that drbg->lock is already locked for write, if non-null.
506 * Returns 1 on success, 0 on failure.
508 int RAND_DRBG_instantiate(RAND_DRBG
*drbg
,
509 const unsigned char *pers
, size_t perslen
)
511 unsigned char *nonce
= NULL
, *entropy
= NULL
;
512 size_t noncelen
= 0, entropylen
= 0;
513 size_t min_entropy
= drbg
->strength
;
514 size_t min_entropylen
= drbg
->min_entropylen
;
515 size_t max_entropylen
= drbg
->max_entropylen
;
517 if (perslen
> drbg
->max_perslen
) {
518 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
519 RAND_R_PERSONALISATION_STRING_TOO_LONG
);
523 if (drbg
->meth
== NULL
) {
524 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
525 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
529 if (drbg
->state
!= DRBG_UNINITIALISED
) {
530 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
531 drbg
->state
== DRBG_ERROR
? RAND_R_IN_ERROR_STATE
532 : RAND_R_ALREADY_INSTANTIATED
);
536 drbg
->state
= DRBG_ERROR
;
539 * NIST SP800-90Ar1 section 9.1 says you can combine getting the entropy
540 * and nonce in 1 call by increasing the entropy with 50% and increasing
541 * the minimum length to accomadate the length of the nonce.
542 * We do this in case a nonce is require and get_nonce is NULL.
544 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
== NULL
) {
545 min_entropy
+= drbg
->strength
/ 2;
546 min_entropylen
+= drbg
->min_noncelen
;
547 max_entropylen
+= drbg
->max_noncelen
;
550 drbg
->reseed_next_counter
= tsan_load(&drbg
->reseed_prop_counter
);
551 if (drbg
->reseed_next_counter
) {
552 drbg
->reseed_next_counter
++;
553 if(!drbg
->reseed_next_counter
)
554 drbg
->reseed_next_counter
= 1;
557 if (drbg
->get_entropy
!= NULL
)
558 entropylen
= drbg
->get_entropy(drbg
, &entropy
, min_entropy
,
559 min_entropylen
, max_entropylen
, 0);
560 if (entropylen
< min_entropylen
561 || entropylen
> max_entropylen
) {
562 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
566 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
!= NULL
) {
567 noncelen
= drbg
->get_nonce(drbg
, &nonce
, drbg
->strength
/ 2,
568 drbg
->min_noncelen
, drbg
->max_noncelen
);
569 if (noncelen
< drbg
->min_noncelen
|| noncelen
> drbg
->max_noncelen
) {
570 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_NONCE
);
575 if (!drbg
->meth
->instantiate(drbg
, entropy
, entropylen
,
576 nonce
, noncelen
, pers
, perslen
)) {
577 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_INSTANTIATING_DRBG
);
581 drbg
->state
= DRBG_READY
;
582 drbg
->reseed_gen_counter
= 1;
583 drbg
->reseed_time
= time(NULL
);
584 tsan_store(&drbg
->reseed_prop_counter
, drbg
->reseed_next_counter
);
587 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
588 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
589 if (nonce
!= NULL
&& drbg
->cleanup_nonce
!= NULL
)
590 drbg
->cleanup_nonce(drbg
, nonce
, noncelen
);
591 if (drbg
->state
== DRBG_READY
)
597 * Uninstantiate |drbg|. Must be instantiated before it can be used.
599 * Requires that drbg->lock is already locked for write, if non-null.
601 * Returns 1 on success, 0 on failure.
603 int RAND_DRBG_uninstantiate(RAND_DRBG
*drbg
)
605 int index
= -1, type
, flags
;
606 if (drbg
->meth
== NULL
) {
607 drbg
->state
= DRBG_ERROR
;
608 RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE
,
609 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
613 /* Clear the entire drbg->ctr struct, then reset some important
614 * members of the drbg->ctr struct (e.g. keysize, df_ks) to their
617 drbg
->meth
->uninstantiate(drbg
);
619 /* The reset uses the default values for type and flags */
620 if (drbg
->flags
& RAND_DRBG_FLAG_MASTER
)
621 index
= RAND_DRBG_TYPE_MASTER
;
622 else if (drbg
->flags
& RAND_DRBG_FLAG_PRIVATE
)
623 index
= RAND_DRBG_TYPE_PRIVATE
;
624 else if (drbg
->flags
& RAND_DRBG_FLAG_PUBLIC
)
625 index
= RAND_DRBG_TYPE_PUBLIC
;
628 flags
= rand_drbg_flags
[index
];
629 type
= rand_drbg_type
[index
];
634 return RAND_DRBG_set(drbg
, type
, flags
);
638 * Reseed |drbg|, mixing in the specified data
640 * Requires that drbg->lock is already locked for write, if non-null.
642 * Returns 1 on success, 0 on failure.
644 int RAND_DRBG_reseed(RAND_DRBG
*drbg
,
645 const unsigned char *adin
, size_t adinlen
,
646 int prediction_resistance
)
648 unsigned char *entropy
= NULL
;
649 size_t entropylen
= 0;
651 if (drbg
->state
== DRBG_ERROR
) {
652 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_IN_ERROR_STATE
);
655 if (drbg
->state
== DRBG_UNINITIALISED
) {
656 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_NOT_INSTANTIATED
);
662 } else if (adinlen
> drbg
->max_adinlen
) {
663 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
667 drbg
->state
= DRBG_ERROR
;
669 drbg
->reseed_next_counter
= tsan_load(&drbg
->reseed_prop_counter
);
670 if (drbg
->reseed_next_counter
) {
671 drbg
->reseed_next_counter
++;
672 if(!drbg
->reseed_next_counter
)
673 drbg
->reseed_next_counter
= 1;
676 if (drbg
->get_entropy
!= NULL
)
677 entropylen
= drbg
->get_entropy(drbg
, &entropy
, drbg
->strength
,
678 drbg
->min_entropylen
,
679 drbg
->max_entropylen
,
680 prediction_resistance
);
681 if (entropylen
< drbg
->min_entropylen
682 || entropylen
> drbg
->max_entropylen
) {
683 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
687 if (!drbg
->meth
->reseed(drbg
, entropy
, entropylen
, adin
, adinlen
))
690 drbg
->state
= DRBG_READY
;
691 drbg
->reseed_gen_counter
= 1;
692 drbg
->reseed_time
= time(NULL
);
693 tsan_store(&drbg
->reseed_prop_counter
, drbg
->reseed_next_counter
);
696 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
697 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
698 if (drbg
->state
== DRBG_READY
)
704 * Restart |drbg|, using the specified entropy or additional input
706 * Tries its best to get the drbg instantiated by all means,
707 * regardless of its current state.
709 * Optionally, a |buffer| of |len| random bytes can be passed,
710 * which is assumed to contain at least |entropy| bits of entropy.
712 * If |entropy| > 0, the buffer content is used as entropy input.
714 * If |entropy| == 0, the buffer content is used as additional input
716 * Returns 1 on success, 0 on failure.
718 * This function is used internally only.
720 int rand_drbg_restart(RAND_DRBG
*drbg
,
721 const unsigned char *buffer
, size_t len
, size_t entropy
)
724 const unsigned char *adin
= NULL
;
727 if (drbg
->seed_pool
!= NULL
) {
728 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
729 drbg
->state
= DRBG_ERROR
;
730 rand_pool_free(drbg
->seed_pool
);
731 drbg
->seed_pool
= NULL
;
735 if (buffer
!= NULL
) {
737 if (drbg
->max_entropylen
< len
) {
738 RANDerr(RAND_F_RAND_DRBG_RESTART
,
739 RAND_R_ENTROPY_INPUT_TOO_LONG
);
740 drbg
->state
= DRBG_ERROR
;
744 if (entropy
> 8 * len
) {
745 RANDerr(RAND_F_RAND_DRBG_RESTART
, RAND_R_ENTROPY_OUT_OF_RANGE
);
746 drbg
->state
= DRBG_ERROR
;
750 /* will be picked up by the rand_drbg_get_entropy() callback */
751 drbg
->seed_pool
= rand_pool_attach(buffer
, len
, entropy
);
752 if (drbg
->seed_pool
== NULL
)
755 if (drbg
->max_adinlen
< len
) {
756 RANDerr(RAND_F_RAND_DRBG_RESTART
,
757 RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
758 drbg
->state
= DRBG_ERROR
;
766 /* repair error state */
767 if (drbg
->state
== DRBG_ERROR
)
768 RAND_DRBG_uninstantiate(drbg
);
770 /* repair uninitialized state */
771 if (drbg
->state
== DRBG_UNINITIALISED
) {
772 /* reinstantiate drbg */
773 RAND_DRBG_instantiate(drbg
,
774 (const unsigned char *) ossl_pers_string
,
775 sizeof(ossl_pers_string
) - 1);
776 /* already reseeded. prevent second reseeding below */
777 reseeded
= (drbg
->state
== DRBG_READY
);
780 /* refresh current state if entropy or additional input has been provided */
781 if (drbg
->state
== DRBG_READY
) {
784 * mix in additional input without reseeding
786 * Similar to RAND_DRBG_reseed(), but the provided additional
787 * data |adin| is mixed into the current state without pulling
788 * entropy from the trusted entropy source using get_entropy().
789 * This is not a reseeding in the strict sense of NIST SP 800-90A.
791 drbg
->meth
->reseed(drbg
, adin
, adinlen
, NULL
, 0);
792 } else if (reseeded
== 0) {
793 /* do a full reseeding if it has not been done yet above */
794 RAND_DRBG_reseed(drbg
, NULL
, 0, 0);
798 rand_pool_free(drbg
->seed_pool
);
799 drbg
->seed_pool
= NULL
;
801 return drbg
->state
== DRBG_READY
;
805 * Generate |outlen| bytes into the buffer at |out|. Reseed if we need
806 * to or if |prediction_resistance| is set. Additional input can be
807 * sent in |adin| and |adinlen|.
809 * Requires that drbg->lock is already locked for write, if non-null.
811 * Returns 1 on success, 0 on failure.
814 int RAND_DRBG_generate(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
,
815 int prediction_resistance
,
816 const unsigned char *adin
, size_t adinlen
)
818 int reseed_required
= 0;
820 if (drbg
->state
!= DRBG_READY
) {
821 /* try to recover from previous errors */
822 rand_drbg_restart(drbg
, NULL
, 0, 0);
824 if (drbg
->state
== DRBG_ERROR
) {
825 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_IN_ERROR_STATE
);
828 if (drbg
->state
== DRBG_UNINITIALISED
) {
829 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_NOT_INSTANTIATED
);
834 if (outlen
> drbg
->max_request
) {
835 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG
);
838 if (adinlen
> drbg
->max_adinlen
) {
839 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
843 if (drbg
->fork_count
!= rand_fork_count
) {
844 drbg
->fork_count
= rand_fork_count
;
848 if (drbg
->reseed_interval
> 0) {
849 if (drbg
->reseed_gen_counter
> drbg
->reseed_interval
)
852 if (drbg
->reseed_time_interval
> 0) {
853 time_t now
= time(NULL
);
854 if (now
< drbg
->reseed_time
855 || now
- drbg
->reseed_time
>= drbg
->reseed_time_interval
)
858 if (drbg
->parent
!= NULL
) {
859 unsigned int reseed_counter
= tsan_load(&drbg
->reseed_prop_counter
);
860 if (reseed_counter
> 0
861 && tsan_load(&drbg
->parent
->reseed_prop_counter
)
866 if (reseed_required
|| prediction_resistance
) {
867 if (!RAND_DRBG_reseed(drbg
, adin
, adinlen
, prediction_resistance
)) {
868 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_RESEED_ERROR
);
875 if (!drbg
->meth
->generate(drbg
, out
, outlen
, adin
, adinlen
)) {
876 drbg
->state
= DRBG_ERROR
;
877 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_GENERATE_ERROR
);
881 drbg
->reseed_gen_counter
++;
887 * Generates |outlen| random bytes and stores them in |out|. It will
888 * using the given |drbg| to generate the bytes.
890 * Requires that drbg->lock is already locked for write, if non-null.
892 * Returns 1 on success 0 on failure.
894 int RAND_DRBG_bytes(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
)
896 unsigned char *additional
= NULL
;
897 size_t additional_len
;
901 if (drbg
->adin_pool
== NULL
) {
904 drbg
->adin_pool
= rand_pool_new(0, 0, drbg
->max_adinlen
);
905 if (drbg
->adin_pool
== NULL
)
909 additional_len
= rand_drbg_get_additional_data(drbg
->adin_pool
,
912 for ( ; outlen
> 0; outlen
-= chunk
, out
+= chunk
) {
914 if (chunk
> drbg
->max_request
)
915 chunk
= drbg
->max_request
;
916 ret
= RAND_DRBG_generate(drbg
, out
, chunk
, 0, additional
, additional_len
);
923 if (additional
!= NULL
)
924 rand_drbg_cleanup_additional_data(drbg
->adin_pool
, additional
);
930 * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
932 * Setting the callbacks is allowed only if the drbg has not been
933 * initialized yet. Otherwise, the operation will fail.
935 * Returns 1 on success, 0 on failure.
937 int RAND_DRBG_set_callbacks(RAND_DRBG
*drbg
,
938 RAND_DRBG_get_entropy_fn get_entropy
,
939 RAND_DRBG_cleanup_entropy_fn cleanup_entropy
,
940 RAND_DRBG_get_nonce_fn get_nonce
,
941 RAND_DRBG_cleanup_nonce_fn cleanup_nonce
)
943 if (drbg
->state
!= DRBG_UNINITIALISED
944 || drbg
->parent
!= NULL
)
946 drbg
->get_entropy
= get_entropy
;
947 drbg
->cleanup_entropy
= cleanup_entropy
;
948 drbg
->get_nonce
= get_nonce
;
949 drbg
->cleanup_nonce
= cleanup_nonce
;
954 * Set the reseed interval.
956 * The drbg will reseed automatically whenever the number of generate
957 * requests exceeds the given reseed interval. If the reseed interval
958 * is 0, then this feature is disabled.
960 * Returns 1 on success, 0 on failure.
962 int RAND_DRBG_set_reseed_interval(RAND_DRBG
*drbg
, unsigned int interval
)
964 if (interval
> MAX_RESEED_INTERVAL
)
966 drbg
->reseed_interval
= interval
;
971 * Set the reseed time interval.
973 * The drbg will reseed automatically whenever the time elapsed since
974 * the last reseeding exceeds the given reseed time interval. For safety,
975 * a reseeding will also occur if the clock has been reset to a smaller
978 * Returns 1 on success, 0 on failure.
980 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG
*drbg
, time_t interval
)
982 if (interval
> MAX_RESEED_TIME_INTERVAL
)
984 drbg
->reseed_time_interval
= interval
;
989 * Set the default values for reseed (time) intervals of new DRBG instances
991 * The default values can be set independently for master DRBG instances
992 * (without a parent) and slave DRBG instances (with parent).
994 * Returns 1 on success, 0 on failure.
997 int RAND_DRBG_set_reseed_defaults(
998 unsigned int _master_reseed_interval
,
999 unsigned int _slave_reseed_interval
,
1000 time_t _master_reseed_time_interval
,
1001 time_t _slave_reseed_time_interval
1004 if (_master_reseed_interval
> MAX_RESEED_INTERVAL
1005 || _slave_reseed_interval
> MAX_RESEED_INTERVAL
)
1008 if (_master_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
1009 || _slave_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
)
1012 master_reseed_interval
= _master_reseed_interval
;
1013 slave_reseed_interval
= _slave_reseed_interval
;
1015 master_reseed_time_interval
= _master_reseed_time_interval
;
1016 slave_reseed_time_interval
= _slave_reseed_time_interval
;
1022 * Locks the given drbg. Locking a drbg which does not have locking
1023 * enabled is considered a successful no-op.
1025 * Returns 1 on success, 0 on failure.
1027 int rand_drbg_lock(RAND_DRBG
*drbg
)
1029 if (drbg
->lock
!= NULL
)
1030 return CRYPTO_THREAD_write_lock(drbg
->lock
);
1036 * Unlocks the given drbg. Unlocking a drbg which does not have locking
1037 * enabled is considered a successful no-op.
1039 * Returns 1 on success, 0 on failure.
1041 int rand_drbg_unlock(RAND_DRBG
*drbg
)
1043 if (drbg
->lock
!= NULL
)
1044 return CRYPTO_THREAD_unlock(drbg
->lock
);
1050 * Enables locking for the given drbg
1052 * Locking can only be enabled if the random generator
1053 * is in the uninitialized state.
1055 * Returns 1 on success, 0 on failure.
1057 int rand_drbg_enable_locking(RAND_DRBG
*drbg
)
1059 if (drbg
->state
!= DRBG_UNINITIALISED
) {
1060 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
1061 RAND_R_DRBG_ALREADY_INITIALIZED
);
1065 if (drbg
->lock
== NULL
) {
1066 if (drbg
->parent
!= NULL
&& drbg
->parent
->lock
== NULL
) {
1067 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
1068 RAND_R_PARENT_LOCKING_NOT_ENABLED
);
1072 drbg
->lock
= CRYPTO_THREAD_lock_new();
1073 if (drbg
->lock
== NULL
) {
1074 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
1075 RAND_R_FAILED_TO_CREATE_LOCK
);
1084 * Get and set the EXDATA
1086 int RAND_DRBG_set_ex_data(RAND_DRBG
*drbg
, int idx
, void *arg
)
1088 return CRYPTO_set_ex_data(&drbg
->ex_data
, idx
, arg
);
1091 void *RAND_DRBG_get_ex_data(const RAND_DRBG
*drbg
, int idx
)
1093 return CRYPTO_get_ex_data(&drbg
->ex_data
, idx
);
1098 * The following functions provide a RAND_METHOD that works on the
1099 * global DRBG. They lock.
1103 * Allocates a new global DRBG on the secure heap (if enabled) and
1104 * initializes it with default settings.
1106 * Returns a pointer to the new DRBG instance on success, NULL on failure.
1108 static RAND_DRBG
*drbg_setup(OPENSSL_CTX
*ctx
, RAND_DRBG
*parent
, int drbg_type
)
1112 drbg
= RAND_DRBG_secure_new_ex(ctx
, rand_drbg_type
[drbg_type
],
1113 rand_drbg_flags
[drbg_type
], parent
);
1117 /* Only the master DRBG needs to have a lock */
1118 if (parent
== NULL
&& rand_drbg_enable_locking(drbg
) == 0)
1121 /* enable seed propagation */
1122 tsan_store(&drbg
->reseed_prop_counter
, 1);
1125 * Ignore instantiation error to support just-in-time instantiation.
1127 * The state of the drbg will be checked in RAND_DRBG_generate() and
1128 * an automatic recovery is attempted.
1130 (void)RAND_DRBG_instantiate(drbg
,
1131 (const unsigned char *) ossl_pers_string
,
1132 sizeof(ossl_pers_string
) - 1);
1136 RAND_DRBG_free(drbg
);
1140 void drbg_delete_thread_state(void)
1142 /* TODO(3.0): Other PRs will pass the ctx as a param to this function */
1143 OPENSSL_CTX
*ctx
= NULL
;
1144 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1149 drbg
= CRYPTO_THREAD_get_local(&dgbl
->public_drbg
);
1150 CRYPTO_THREAD_set_local(&dgbl
->public_drbg
, NULL
);
1151 RAND_DRBG_free(drbg
);
1153 drbg
= CRYPTO_THREAD_get_local(&dgbl
->private_drbg
);
1154 CRYPTO_THREAD_set_local(&dgbl
->private_drbg
, NULL
);
1155 RAND_DRBG_free(drbg
);
1158 /* Implements the default OpenSSL RAND_bytes() method */
1159 static int drbg_bytes(unsigned char *out
, int count
)
1162 RAND_DRBG
*drbg
= RAND_DRBG_get0_public();
1167 ret
= RAND_DRBG_bytes(drbg
, out
, count
);
1173 * Calculates the minimum length of a full entropy buffer
1174 * which is necessary to seed (i.e. instantiate) the DRBG
1177 size_t rand_drbg_seedlen(RAND_DRBG
*drbg
)
1180 * If no os entropy source is available then RAND_seed(buffer, bufsize)
1181 * is expected to succeed if and only if the buffer length satisfies
1182 * the following requirements, which follow from the calculations
1183 * in RAND_DRBG_instantiate().
1185 size_t min_entropy
= drbg
->strength
;
1186 size_t min_entropylen
= drbg
->min_entropylen
;
1189 * Extra entropy for the random nonce in the absence of a
1190 * get_nonce callback, see comment in RAND_DRBG_instantiate().
1192 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
== NULL
) {
1193 min_entropy
+= drbg
->strength
/ 2;
1194 min_entropylen
+= drbg
->min_noncelen
;
1198 * Convert entropy requirement from bits to bytes
1199 * (dividing by 8 without rounding upwards, because
1200 * all entropy requirements are divisible by 8).
1204 /* Return a value that satisfies both requirements */
1205 return min_entropy
> min_entropylen
? min_entropy
: min_entropylen
;
1208 /* Implements the default OpenSSL RAND_add() method */
1209 static int drbg_add(const void *buf
, int num
, double randomness
)
1212 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
1219 if (num
< 0 || randomness
< 0.0)
1222 rand_drbg_lock(drbg
);
1223 seedlen
= rand_drbg_seedlen(drbg
);
1225 buflen
= (size_t)num
;
1229 * NIST SP-800-90A mandates that entropy *shall not* be provided
1230 * by the consuming application. By setting the randomness to zero,
1231 * we ensure that the buffer contents will be added to the internal
1232 * state of the DRBG only as additional data.
1234 * (NIST SP-800-90Ar1, Sections 9.1 and 9.2)
1238 if (buflen
< seedlen
|| randomness
< (double) seedlen
) {
1239 #if defined(OPENSSL_RAND_SEED_NONE)
1241 * If no os entropy source is available, a reseeding will fail
1242 * inevitably. So we use a trick to mix the buffer contents into
1243 * the DRBG state without forcing a reseeding: we generate a
1244 * dummy random byte, using the buffer content as additional data.
1245 * Note: This won't work with RAND_DRBG_FLAG_CTR_NO_DF.
1247 unsigned char dummy
[1];
1249 ret
= RAND_DRBG_generate(drbg
, dummy
, sizeof(dummy
), 0, buf
, buflen
);
1250 rand_drbg_unlock(drbg
);
1254 * If an os entropy source is available then we declare the buffer content
1255 * as additional data by setting randomness to zero and trigger a regular
1262 if (randomness
> (double)seedlen
) {
1264 * The purpose of this check is to bound |randomness| by a
1265 * relatively small value in order to prevent an integer
1266 * overflow when multiplying by 8 in the rand_drbg_restart()
1267 * call below. Note that randomness is measured in bytes,
1268 * not bits, so this value corresponds to eight times the
1269 * security strength.
1271 randomness
= (double)seedlen
;
1274 ret
= rand_drbg_restart(drbg
, buf
, buflen
, (size_t)(8 * randomness
));
1275 rand_drbg_unlock(drbg
);
1280 /* Implements the default OpenSSL RAND_seed() method */
1281 static int drbg_seed(const void *buf
, int num
)
1283 return drbg_add(buf
, num
, num
);
1286 /* Implements the default OpenSSL RAND_status() method */
1287 static int drbg_status(void)
1290 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
1295 rand_drbg_lock(drbg
);
1296 ret
= drbg
->state
== DRBG_READY
? 1 : 0;
1297 rand_drbg_unlock(drbg
);
1302 * Get the master DRBG.
1303 * Returns pointer to the DRBG on success, NULL on failure.
1306 RAND_DRBG
*OPENSSL_CTX_get0_master_drbg(OPENSSL_CTX
*ctx
)
1308 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1313 return dgbl
->master_drbg
;
1316 RAND_DRBG
*RAND_DRBG_get0_master(void)
1318 return OPENSSL_CTX_get0_master_drbg(NULL
);
1322 * Get the public DRBG.
1323 * Returns pointer to the DRBG on success, NULL on failure.
1325 RAND_DRBG
*OPENSSL_CTX_get0_public_drbg(OPENSSL_CTX
*ctx
)
1327 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1333 drbg
= CRYPTO_THREAD_get_local(&dgbl
->public_drbg
);
1335 if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND
))
1337 drbg
= drbg_setup(ctx
, dgbl
->master_drbg
, RAND_DRBG_TYPE_PUBLIC
);
1338 CRYPTO_THREAD_set_local(&dgbl
->public_drbg
, drbg
);
1343 RAND_DRBG
*RAND_DRBG_get0_public(void)
1345 return OPENSSL_CTX_get0_public_drbg(NULL
);
1349 * Get the private DRBG.
1350 * Returns pointer to the DRBG on success, NULL on failure.
1352 RAND_DRBG
*OPENSSL_CTX_get0_private_drbg(OPENSSL_CTX
*ctx
)
1354 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1360 drbg
= CRYPTO_THREAD_get_local(&dgbl
->private_drbg
);
1362 if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND
))
1364 drbg
= drbg_setup(ctx
, dgbl
->master_drbg
, RAND_DRBG_TYPE_PRIVATE
);
1365 CRYPTO_THREAD_set_local(&dgbl
->private_drbg
, drbg
);
1370 RAND_DRBG
*RAND_DRBG_get0_private(void)
1372 return OPENSSL_CTX_get0_private_drbg(NULL
);
1375 RAND_METHOD rand_meth
= {
1384 RAND_METHOD
*RAND_OpenSSL(void)