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>
14 #include "rand_local.h"
15 #include "internal/thread_once.h"
16 #include "crypto/rand.h"
17 #include "crypto/cryptlib.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 rand_drbg_set(RAND_DRBG
*drbg
, int type
, unsigned int flags
);
119 static int rand_drbg_init_method(RAND_DRBG
*drbg
);
121 static int is_ctr(int type
)
124 case NID_aes_128_ctr
:
125 case NID_aes_192_ctr
:
126 case NID_aes_256_ctr
:
133 static int is_digest(int type
)
154 * Initialize the OPENSSL_CTX global DRBGs on first use.
155 * Returns the allocated global data on success or NULL on failure.
157 static void *drbg_ossl_ctx_new(OPENSSL_CTX
*libctx
)
159 DRBG_GLOBAL
*dgbl
= OPENSSL_zalloc(sizeof(*dgbl
));
166 * We need to ensure that base libcrypto thread handling has been
169 OPENSSL_init_crypto(0, NULL
);
172 if (!CRYPTO_THREAD_init_local(&dgbl
->private_drbg
, NULL
))
175 if (!CRYPTO_THREAD_init_local(&dgbl
->public_drbg
, NULL
))
178 dgbl
->master_drbg
= drbg_setup(libctx
, NULL
, RAND_DRBG_TYPE_MASTER
);
179 if (dgbl
->master_drbg
== NULL
)
185 CRYPTO_THREAD_cleanup_local(&dgbl
->public_drbg
);
187 CRYPTO_THREAD_cleanup_local(&dgbl
->private_drbg
);
193 static void drbg_ossl_ctx_free(void *vdgbl
)
195 DRBG_GLOBAL
*dgbl
= vdgbl
;
200 RAND_DRBG_free(dgbl
->master_drbg
);
201 CRYPTO_THREAD_cleanup_local(&dgbl
->private_drbg
);
202 CRYPTO_THREAD_cleanup_local(&dgbl
->public_drbg
);
207 static const OPENSSL_CTX_METHOD drbg_ossl_ctx_method
= {
213 * drbg_ossl_ctx_new() calls drgb_setup() which calls rand_drbg_get_nonce()
214 * which needs to get the rand_nonce_lock out of the OPENSSL_CTX...but since
215 * drbg_ossl_ctx_new() hasn't finished running yet we need the rand_nonce_lock
216 * to be in a different global data object. Otherwise we will go into an
217 * infinite recursion loop.
219 static void *drbg_nonce_ossl_ctx_new(OPENSSL_CTX
*libctx
)
221 DRBG_NONCE_GLOBAL
*dngbl
= OPENSSL_zalloc(sizeof(*dngbl
));
226 dngbl
->rand_nonce_lock
= CRYPTO_THREAD_lock_new();
227 if (dngbl
->rand_nonce_lock
== NULL
) {
235 static void drbg_nonce_ossl_ctx_free(void *vdngbl
)
237 DRBG_NONCE_GLOBAL
*dngbl
= vdngbl
;
242 CRYPTO_THREAD_lock_free(dngbl
->rand_nonce_lock
);
247 static const OPENSSL_CTX_METHOD drbg_nonce_ossl_ctx_method
= {
248 drbg_nonce_ossl_ctx_new
,
249 drbg_nonce_ossl_ctx_free
,
252 static DRBG_GLOBAL
*drbg_get_global(OPENSSL_CTX
*libctx
)
254 return openssl_ctx_get_data(libctx
, OPENSSL_CTX_DRBG_INDEX
,
255 &drbg_ossl_ctx_method
);
258 /* Implements the get_nonce() callback (see RAND_DRBG_set_callbacks()) */
259 size_t rand_drbg_get_nonce(RAND_DRBG
*drbg
,
260 unsigned char **pout
,
261 int entropy
, size_t min_len
, size_t max_len
)
265 DRBG_NONCE_GLOBAL
*dngbl
266 = openssl_ctx_get_data(drbg
->libctx
, OPENSSL_CTX_DRBG_NONCE_INDEX
,
267 &drbg_nonce_ossl_ctx_method
);
276 memset(&data
, 0, sizeof(data
));
277 pool
= rand_pool_new(0, 0, min_len
, max_len
);
281 if (rand_pool_add_nonce_data(pool
) == 0)
284 data
.instance
= drbg
;
285 CRYPTO_atomic_add(&dngbl
->rand_nonce_count
, 1, &data
.count
,
286 dngbl
->rand_nonce_lock
);
288 if (rand_pool_add(pool
, (unsigned char *)&data
, sizeof(data
), 0) == 0)
291 ret
= rand_pool_length(pool
);
292 *pout
= rand_pool_detach(pool
);
295 rand_pool_free(pool
);
301 * Implements the cleanup_nonce() callback (see RAND_DRBG_set_callbacks())
304 void rand_drbg_cleanup_nonce(RAND_DRBG
*drbg
,
305 unsigned char *out
, size_t outlen
)
307 OPENSSL_clear_free(out
, outlen
);
311 * Set the |drbg|'s callback data pointer for the entropy and nonce callbacks
313 * The ownership of the context data remains with the caller,
314 * i.e., it is the caller's responsibility to keep it available as long
315 * as it is need by the callbacks and free it after use.
317 * Setting the callback data is allowed only if the drbg has not been
318 * initialized yet. Otherwise, the operation will fail.
320 * Returns 1 on success, 0 on failure.
322 int RAND_DRBG_set_callback_data(RAND_DRBG
*drbg
, void *data
)
324 if (drbg
->state
!= DRBG_UNINITIALISED
325 || drbg
->parent
!= NULL
)
328 drbg
->callback_data
= data
;
332 /* Retrieve the callback data pointer */
333 void *RAND_DRBG_get_callback_data(RAND_DRBG
*drbg
)
335 return drbg
->callback_data
;
339 * Set/initialize |drbg| to be of type |type|, with optional |flags|.
341 * If |type| and |flags| are zero, use the defaults
343 * Returns 1 on success, 0 on failure.
345 int RAND_DRBG_set(RAND_DRBG
*drbg
, int type
, unsigned int flags
)
347 return rand_drbg_set(drbg
, type
, flags
) && rand_drbg_init_method(drbg
);
350 static int rand_drbg_set(RAND_DRBG
*drbg
, int type
, unsigned int flags
)
352 if (type
== 0 && flags
== 0) {
353 type
= rand_drbg_type
[RAND_DRBG_TYPE_MASTER
];
354 flags
= rand_drbg_flags
[RAND_DRBG_TYPE_MASTER
];
357 /* If set is called multiple times - clear the old one */
358 if (drbg
->type
!= 0 && (type
!= drbg
->type
|| flags
!= drbg
->flags
)) {
359 if (drbg
->meth
!= NULL
)
360 drbg
->meth
->uninstantiate(drbg
);
361 rand_pool_free(drbg
->adin_pool
);
362 drbg
->adin_pool
= NULL
;
365 drbg
->state
= DRBG_UNINITIALISED
;
370 if (type
== 0 || is_ctr(type
) || is_digest(type
))
375 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
380 static int rand_drbg_init_method(RAND_DRBG
*drbg
)
384 if (drbg
->meth
!= NULL
)
387 if (is_ctr(drbg
->type
)) {
388 ret
= drbg_ctr_init(drbg
);
389 } else if (is_digest(drbg
->type
)) {
390 if (drbg
->flags
& RAND_DRBG_FLAG_HMAC
)
391 ret
= drbg_hmac_init(drbg
);
393 ret
= drbg_hash_init(drbg
);
395 /* other cases should already be excluded */
396 RANDerr(RAND_F_RAND_DRBG_INIT_METHOD
, ERR_R_INTERNAL_ERROR
);
403 drbg
->state
= DRBG_ERROR
;
404 RANDerr(RAND_F_RAND_DRBG_INIT_METHOD
, RAND_R_ERROR_INITIALISING_DRBG
);
410 * Set/initialize default |type| and |flag| for new drbg instances.
412 * Returns 1 on success, 0 on failure.
414 int RAND_DRBG_set_defaults(int type
, unsigned int flags
)
417 if (!(is_digest(type
) || is_ctr(type
))) {
418 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
422 if ((flags
& ~rand_drbg_used_flags
) != 0) {
423 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS
, RAND_R_UNSUPPORTED_DRBG_FLAGS
);
427 all
= ((flags
& RAND_DRBG_TYPE_FLAGS
) == 0);
428 if (all
|| (flags
& RAND_DRBG_FLAG_MASTER
) != 0) {
429 rand_drbg_type
[RAND_DRBG_TYPE_MASTER
] = type
;
430 rand_drbg_flags
[RAND_DRBG_TYPE_MASTER
] = flags
| RAND_DRBG_FLAG_MASTER
;
432 if (all
|| (flags
& RAND_DRBG_FLAG_PUBLIC
) != 0) {
433 rand_drbg_type
[RAND_DRBG_TYPE_PUBLIC
] = type
;
434 rand_drbg_flags
[RAND_DRBG_TYPE_PUBLIC
] = flags
| RAND_DRBG_FLAG_PUBLIC
;
436 if (all
|| (flags
& RAND_DRBG_FLAG_PRIVATE
) != 0) {
437 rand_drbg_type
[RAND_DRBG_TYPE_PRIVATE
] = type
;
438 rand_drbg_flags
[RAND_DRBG_TYPE_PRIVATE
] = flags
| RAND_DRBG_FLAG_PRIVATE
;
445 * Allocate memory and initialize a new DRBG. The DRBG is allocated on
446 * the secure heap if |secure| is nonzero and the secure heap is enabled.
447 * The |parent|, if not NULL, will be used as random source for reseeding.
449 * Returns a pointer to the new DRBG instance on success, NULL on failure.
451 static RAND_DRBG
*rand_drbg_new(OPENSSL_CTX
*ctx
,
457 RAND_DRBG
*drbg
= secure
? OPENSSL_secure_zalloc(sizeof(*drbg
))
458 : OPENSSL_zalloc(sizeof(*drbg
));
461 RANDerr(RAND_F_RAND_DRBG_NEW
, ERR_R_MALLOC_FAILURE
);
466 drbg
->secure
= secure
&& CRYPTO_secure_allocated(drbg
);
467 drbg
->fork_id
= openssl_get_fork_id();
468 drbg
->parent
= parent
;
470 if (parent
== NULL
) {
472 drbg
->get_entropy
= rand_crngt_get_entropy
;
473 drbg
->cleanup_entropy
= rand_crngt_cleanup_entropy
;
475 drbg
->get_entropy
= rand_drbg_get_entropy
;
476 drbg
->cleanup_entropy
= rand_drbg_cleanup_entropy
;
478 #ifndef RAND_DRBG_GET_RANDOM_NONCE
479 drbg
->get_nonce
= rand_drbg_get_nonce
;
480 drbg
->cleanup_nonce
= rand_drbg_cleanup_nonce
;
483 drbg
->reseed_interval
= master_reseed_interval
;
484 drbg
->reseed_time_interval
= master_reseed_time_interval
;
486 drbg
->get_entropy
= rand_drbg_get_entropy
;
487 drbg
->cleanup_entropy
= rand_drbg_cleanup_entropy
;
489 * Do not provide nonce callbacks, the child DRBGs will
490 * obtain their nonce using random bits from the parent.
493 drbg
->reseed_interval
= slave_reseed_interval
;
494 drbg
->reseed_time_interval
= slave_reseed_time_interval
;
497 if (RAND_DRBG_set(drbg
, type
, flags
) == 0)
500 if (parent
!= NULL
) {
501 rand_drbg_lock(parent
);
502 if (drbg
->strength
> parent
->strength
) {
504 * We currently don't support the algorithm from NIST SP 800-90C
505 * 10.1.2 to use a weaker DRBG as source
507 rand_drbg_unlock(parent
);
508 RANDerr(RAND_F_RAND_DRBG_NEW
, RAND_R_PARENT_STRENGTH_TOO_WEAK
);
511 rand_drbg_unlock(parent
);
517 RAND_DRBG_free(drbg
);
522 RAND_DRBG
*RAND_DRBG_new_ex(OPENSSL_CTX
*ctx
, int type
, unsigned int flags
,
525 return rand_drbg_new(ctx
, 0, type
, flags
, parent
);
528 RAND_DRBG
*RAND_DRBG_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
530 return RAND_DRBG_new_ex(NULL
, type
, flags
, parent
);
533 RAND_DRBG
*RAND_DRBG_secure_new_ex(OPENSSL_CTX
*ctx
, int type
,
534 unsigned int flags
, RAND_DRBG
*parent
)
536 return rand_drbg_new(ctx
, 1, type
, flags
, parent
);
539 RAND_DRBG
*RAND_DRBG_secure_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
541 return RAND_DRBG_secure_new_ex(NULL
, type
, flags
, parent
);
544 * Uninstantiate |drbg| and free all memory.
546 void RAND_DRBG_free(RAND_DRBG
*drbg
)
551 if (drbg
->meth
!= NULL
)
552 drbg
->meth
->uninstantiate(drbg
);
553 rand_pool_free(drbg
->adin_pool
);
554 CRYPTO_THREAD_lock_free(drbg
->lock
);
556 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_RAND_DRBG
, drbg
, &drbg
->ex_data
);
560 OPENSSL_secure_clear_free(drbg
, sizeof(*drbg
));
562 OPENSSL_clear_free(drbg
, sizeof(*drbg
));
566 * Instantiate |drbg|, after it has been initialized. Use |pers| and
567 * |perslen| as prediction-resistance input.
569 * Requires that drbg->lock is already locked for write, if non-null.
571 * Returns 1 on success, 0 on failure.
573 int RAND_DRBG_instantiate(RAND_DRBG
*drbg
,
574 const unsigned char *pers
, size_t perslen
)
576 unsigned char *nonce
= NULL
, *entropy
= NULL
;
577 size_t noncelen
= 0, entropylen
= 0;
578 size_t min_entropy
, min_entropylen
, max_entropylen
;
580 if (drbg
->meth
== NULL
&& !rand_drbg_init_method(drbg
)) {
581 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
582 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
586 min_entropy
= drbg
->strength
;
587 min_entropylen
= drbg
->min_entropylen
;
588 max_entropylen
= drbg
->max_entropylen
;
590 if (perslen
> drbg
->max_perslen
) {
591 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
592 RAND_R_PERSONALISATION_STRING_TOO_LONG
);
596 if (drbg
->state
!= DRBG_UNINITIALISED
) {
597 if (drbg
->state
== DRBG_ERROR
)
598 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_IN_ERROR_STATE
);
600 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ALREADY_INSTANTIATED
);
604 drbg
->state
= DRBG_ERROR
;
607 * NIST SP800-90Ar1 section 9.1 says you can combine getting the entropy
608 * and nonce in 1 call by increasing the entropy with 50% and increasing
609 * the minimum length to accommodate the length of the nonce.
610 * We do this in case a nonce is require and get_nonce is NULL.
612 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
== NULL
) {
613 min_entropy
+= drbg
->strength
/ 2;
614 min_entropylen
+= drbg
->min_noncelen
;
615 max_entropylen
+= drbg
->max_noncelen
;
618 drbg
->reseed_next_counter
= tsan_load(&drbg
->reseed_prop_counter
);
619 if (drbg
->reseed_next_counter
) {
620 drbg
->reseed_next_counter
++;
621 if(!drbg
->reseed_next_counter
)
622 drbg
->reseed_next_counter
= 1;
625 if (drbg
->get_entropy
!= NULL
)
626 entropylen
= drbg
->get_entropy(drbg
, &entropy
, min_entropy
,
627 min_entropylen
, max_entropylen
, 0);
628 if (entropylen
< min_entropylen
629 || entropylen
> max_entropylen
) {
630 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
634 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
!= NULL
) {
635 noncelen
= drbg
->get_nonce(drbg
, &nonce
, drbg
->strength
/ 2,
636 drbg
->min_noncelen
, drbg
->max_noncelen
);
637 if (noncelen
< drbg
->min_noncelen
|| noncelen
> drbg
->max_noncelen
) {
638 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_NONCE
);
643 if (!drbg
->meth
->instantiate(drbg
, entropy
, entropylen
,
644 nonce
, noncelen
, pers
, perslen
)) {
645 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_INSTANTIATING_DRBG
);
649 drbg
->state
= DRBG_READY
;
650 drbg
->reseed_gen_counter
= 1;
651 drbg
->reseed_time
= time(NULL
);
652 tsan_store(&drbg
->reseed_prop_counter
, drbg
->reseed_next_counter
);
655 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
656 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
657 if (nonce
!= NULL
&& drbg
->cleanup_nonce
!= NULL
)
658 drbg
->cleanup_nonce(drbg
, nonce
, noncelen
);
659 if (drbg
->state
== DRBG_READY
)
665 * Uninstantiate |drbg|. Must be instantiated before it can be used.
667 * Requires that drbg->lock is already locked for write, if non-null.
669 * Returns 1 on success, 0 on failure.
671 int RAND_DRBG_uninstantiate(RAND_DRBG
*drbg
)
673 int index
= -1, type
, flags
;
674 if (drbg
->meth
!= NULL
) {
675 drbg
->meth
->uninstantiate(drbg
);
679 /* The reset uses the default values for type and flags */
680 if (drbg
->flags
& RAND_DRBG_FLAG_MASTER
)
681 index
= RAND_DRBG_TYPE_MASTER
;
682 else if (drbg
->flags
& RAND_DRBG_FLAG_PRIVATE
)
683 index
= RAND_DRBG_TYPE_PRIVATE
;
684 else if (drbg
->flags
& RAND_DRBG_FLAG_PUBLIC
)
685 index
= RAND_DRBG_TYPE_PUBLIC
;
688 flags
= rand_drbg_flags
[index
];
689 type
= rand_drbg_type
[index
];
694 return rand_drbg_set(drbg
, type
, flags
);
698 * Reseed |drbg|, mixing in the specified data
700 * Requires that drbg->lock is already locked for write, if non-null.
702 * Returns 1 on success, 0 on failure.
704 int RAND_DRBG_reseed(RAND_DRBG
*drbg
,
705 const unsigned char *adin
, size_t adinlen
,
706 int prediction_resistance
)
708 unsigned char *entropy
= NULL
;
709 size_t entropylen
= 0;
711 if (drbg
->state
== DRBG_ERROR
) {
712 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_IN_ERROR_STATE
);
715 if (drbg
->state
== DRBG_UNINITIALISED
) {
716 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_NOT_INSTANTIATED
);
722 } else if (adinlen
> drbg
->max_adinlen
) {
723 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
727 drbg
->state
= DRBG_ERROR
;
729 drbg
->reseed_next_counter
= tsan_load(&drbg
->reseed_prop_counter
);
730 if (drbg
->reseed_next_counter
) {
731 drbg
->reseed_next_counter
++;
732 if(!drbg
->reseed_next_counter
)
733 drbg
->reseed_next_counter
= 1;
736 if (drbg
->get_entropy
!= NULL
)
737 entropylen
= drbg
->get_entropy(drbg
, &entropy
, drbg
->strength
,
738 drbg
->min_entropylen
,
739 drbg
->max_entropylen
,
740 prediction_resistance
);
741 if (entropylen
< drbg
->min_entropylen
742 || entropylen
> drbg
->max_entropylen
) {
743 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
747 if (!drbg
->meth
->reseed(drbg
, entropy
, entropylen
, adin
, adinlen
))
750 drbg
->state
= DRBG_READY
;
751 drbg
->reseed_gen_counter
= 1;
752 drbg
->reseed_time
= time(NULL
);
753 tsan_store(&drbg
->reseed_prop_counter
, drbg
->reseed_next_counter
);
756 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
757 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
758 if (drbg
->state
== DRBG_READY
)
764 * Restart |drbg|, using the specified entropy or additional input
766 * Tries its best to get the drbg instantiated by all means,
767 * regardless of its current state.
769 * Optionally, a |buffer| of |len| random bytes can be passed,
770 * which is assumed to contain at least |entropy| bits of entropy.
772 * If |entropy| > 0, the buffer content is used as entropy input.
774 * If |entropy| == 0, the buffer content is used as additional input
776 * Returns 1 on success, 0 on failure.
778 * This function is used internally only.
780 int rand_drbg_restart(RAND_DRBG
*drbg
,
781 const unsigned char *buffer
, size_t len
, size_t entropy
)
784 const unsigned char *adin
= NULL
;
787 if (drbg
->seed_pool
!= NULL
) {
788 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
789 drbg
->state
= DRBG_ERROR
;
790 rand_pool_free(drbg
->seed_pool
);
791 drbg
->seed_pool
= NULL
;
795 if (buffer
!= NULL
) {
797 if (drbg
->max_entropylen
< len
) {
798 RANDerr(RAND_F_RAND_DRBG_RESTART
,
799 RAND_R_ENTROPY_INPUT_TOO_LONG
);
800 drbg
->state
= DRBG_ERROR
;
804 if (entropy
> 8 * len
) {
805 RANDerr(RAND_F_RAND_DRBG_RESTART
, RAND_R_ENTROPY_OUT_OF_RANGE
);
806 drbg
->state
= DRBG_ERROR
;
810 /* will be picked up by the rand_drbg_get_entropy() callback */
811 drbg
->seed_pool
= rand_pool_attach(buffer
, len
, entropy
);
812 if (drbg
->seed_pool
== NULL
)
815 if (drbg
->max_adinlen
< len
) {
816 RANDerr(RAND_F_RAND_DRBG_RESTART
,
817 RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
818 drbg
->state
= DRBG_ERROR
;
826 /* repair error state */
827 if (drbg
->state
== DRBG_ERROR
)
828 RAND_DRBG_uninstantiate(drbg
);
830 /* repair uninitialized state */
831 if (drbg
->state
== DRBG_UNINITIALISED
) {
832 /* reinstantiate drbg */
833 RAND_DRBG_instantiate(drbg
,
834 (const unsigned char *) ossl_pers_string
,
835 sizeof(ossl_pers_string
) - 1);
836 /* already reseeded. prevent second reseeding below */
837 reseeded
= (drbg
->state
== DRBG_READY
);
840 /* refresh current state if entropy or additional input has been provided */
841 if (drbg
->state
== DRBG_READY
) {
844 * mix in additional input without reseeding
846 * Similar to RAND_DRBG_reseed(), but the provided additional
847 * data |adin| is mixed into the current state without pulling
848 * entropy from the trusted entropy source using get_entropy().
849 * This is not a reseeding in the strict sense of NIST SP 800-90A.
851 drbg
->meth
->reseed(drbg
, adin
, adinlen
, NULL
, 0);
852 } else if (reseeded
== 0) {
853 /* do a full reseeding if it has not been done yet above */
854 RAND_DRBG_reseed(drbg
, NULL
, 0, 0);
858 rand_pool_free(drbg
->seed_pool
);
859 drbg
->seed_pool
= NULL
;
861 return drbg
->state
== DRBG_READY
;
865 * Generate |outlen| bytes into the buffer at |out|. Reseed if we need
866 * to or if |prediction_resistance| is set. Additional input can be
867 * sent in |adin| and |adinlen|.
869 * Requires that drbg->lock is already locked for write, if non-null.
871 * Returns 1 on success, 0 on failure.
874 int RAND_DRBG_generate(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
,
875 int prediction_resistance
,
876 const unsigned char *adin
, size_t adinlen
)
879 int reseed_required
= 0;
881 if (drbg
->state
!= DRBG_READY
) {
882 /* try to recover from previous errors */
883 rand_drbg_restart(drbg
, NULL
, 0, 0);
885 if (drbg
->state
== DRBG_ERROR
) {
886 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_IN_ERROR_STATE
);
889 if (drbg
->state
== DRBG_UNINITIALISED
) {
890 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_NOT_INSTANTIATED
);
895 if (outlen
> drbg
->max_request
) {
896 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG
);
899 if (adinlen
> drbg
->max_adinlen
) {
900 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
904 fork_id
= openssl_get_fork_id();
906 if (drbg
->fork_id
!= fork_id
) {
907 drbg
->fork_id
= fork_id
;
911 if (drbg
->reseed_interval
> 0) {
912 if (drbg
->reseed_gen_counter
> drbg
->reseed_interval
)
915 if (drbg
->reseed_time_interval
> 0) {
916 time_t now
= time(NULL
);
917 if (now
< drbg
->reseed_time
918 || now
- drbg
->reseed_time
>= drbg
->reseed_time_interval
)
921 if (drbg
->parent
!= NULL
) {
922 unsigned int reseed_counter
= tsan_load(&drbg
->reseed_prop_counter
);
923 if (reseed_counter
> 0
924 && tsan_load(&drbg
->parent
->reseed_prop_counter
)
929 if (reseed_required
|| prediction_resistance
) {
930 if (!RAND_DRBG_reseed(drbg
, adin
, adinlen
, prediction_resistance
)) {
931 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_RESEED_ERROR
);
938 if (!drbg
->meth
->generate(drbg
, out
, outlen
, adin
, adinlen
)) {
939 drbg
->state
= DRBG_ERROR
;
940 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_GENERATE_ERROR
);
944 drbg
->reseed_gen_counter
++;
950 * Generates |outlen| random bytes and stores them in |out|. It will
951 * using the given |drbg| to generate the bytes.
953 * Requires that drbg->lock is already locked for write, if non-null.
955 * Returns 1 on success 0 on failure.
957 int RAND_DRBG_bytes(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
)
959 unsigned char *additional
= NULL
;
960 size_t additional_len
;
964 if (drbg
->adin_pool
== NULL
) {
967 drbg
->adin_pool
= rand_pool_new(0, 0, 0, drbg
->max_adinlen
);
968 if (drbg
->adin_pool
== NULL
)
972 additional_len
= rand_drbg_get_additional_data(drbg
->adin_pool
,
975 for ( ; outlen
> 0; outlen
-= chunk
, out
+= chunk
) {
977 if (chunk
> drbg
->max_request
)
978 chunk
= drbg
->max_request
;
979 ret
= RAND_DRBG_generate(drbg
, out
, chunk
, 0, additional
, additional_len
);
986 if (additional
!= NULL
)
987 rand_drbg_cleanup_additional_data(drbg
->adin_pool
, additional
);
993 * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
995 * Setting the callbacks is allowed only if the drbg has not been
996 * initialized yet. Otherwise, the operation will fail.
998 * Returns 1 on success, 0 on failure.
1000 int RAND_DRBG_set_callbacks(RAND_DRBG
*drbg
,
1001 RAND_DRBG_get_entropy_fn get_entropy
,
1002 RAND_DRBG_cleanup_entropy_fn cleanup_entropy
,
1003 RAND_DRBG_get_nonce_fn get_nonce
,
1004 RAND_DRBG_cleanup_nonce_fn cleanup_nonce
)
1006 if (drbg
->state
!= DRBG_UNINITIALISED
1007 || drbg
->parent
!= NULL
)
1009 drbg
->get_entropy
= get_entropy
;
1010 drbg
->cleanup_entropy
= cleanup_entropy
;
1011 drbg
->get_nonce
= get_nonce
;
1012 drbg
->cleanup_nonce
= cleanup_nonce
;
1017 * Set the reseed interval.
1019 * The drbg will reseed automatically whenever the number of generate
1020 * requests exceeds the given reseed interval. If the reseed interval
1021 * is 0, then this feature is disabled.
1023 * Returns 1 on success, 0 on failure.
1025 int RAND_DRBG_set_reseed_interval(RAND_DRBG
*drbg
, unsigned int interval
)
1027 if (interval
> MAX_RESEED_INTERVAL
)
1029 drbg
->reseed_interval
= interval
;
1034 * Set the reseed time interval.
1036 * The drbg will reseed automatically whenever the time elapsed since
1037 * the last reseeding exceeds the given reseed time interval. For safety,
1038 * a reseeding will also occur if the clock has been reset to a smaller
1041 * Returns 1 on success, 0 on failure.
1043 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG
*drbg
, time_t interval
)
1045 if (interval
> MAX_RESEED_TIME_INTERVAL
)
1047 drbg
->reseed_time_interval
= interval
;
1052 * Set the default values for reseed (time) intervals of new DRBG instances
1054 * The default values can be set independently for master DRBG instances
1055 * (without a parent) and slave DRBG instances (with parent).
1057 * Returns 1 on success, 0 on failure.
1060 int RAND_DRBG_set_reseed_defaults(
1061 unsigned int _master_reseed_interval
,
1062 unsigned int _slave_reseed_interval
,
1063 time_t _master_reseed_time_interval
,
1064 time_t _slave_reseed_time_interval
1067 if (_master_reseed_interval
> MAX_RESEED_INTERVAL
1068 || _slave_reseed_interval
> MAX_RESEED_INTERVAL
)
1071 if (_master_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
1072 || _slave_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
)
1075 master_reseed_interval
= _master_reseed_interval
;
1076 slave_reseed_interval
= _slave_reseed_interval
;
1078 master_reseed_time_interval
= _master_reseed_time_interval
;
1079 slave_reseed_time_interval
= _slave_reseed_time_interval
;
1085 * Locks the given drbg. Locking a drbg which does not have locking
1086 * enabled is considered a successful no-op.
1088 * Returns 1 on success, 0 on failure.
1090 int rand_drbg_lock(RAND_DRBG
*drbg
)
1092 if (drbg
->lock
!= NULL
)
1093 return CRYPTO_THREAD_write_lock(drbg
->lock
);
1099 * Unlocks the given drbg. Unlocking a drbg which does not have locking
1100 * enabled is considered a successful no-op.
1102 * Returns 1 on success, 0 on failure.
1104 int rand_drbg_unlock(RAND_DRBG
*drbg
)
1106 if (drbg
->lock
!= NULL
)
1107 return CRYPTO_THREAD_unlock(drbg
->lock
);
1113 * Enables locking for the given drbg
1115 * Locking can only be enabled if the random generator
1116 * is in the uninitialized state.
1118 * Returns 1 on success, 0 on failure.
1120 int rand_drbg_enable_locking(RAND_DRBG
*drbg
)
1122 if (drbg
->state
!= DRBG_UNINITIALISED
) {
1123 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
1124 RAND_R_DRBG_ALREADY_INITIALIZED
);
1128 if (drbg
->lock
== NULL
) {
1129 if (drbg
->parent
!= NULL
&& drbg
->parent
->lock
== NULL
) {
1130 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
1131 RAND_R_PARENT_LOCKING_NOT_ENABLED
);
1135 drbg
->lock
= CRYPTO_THREAD_lock_new();
1136 if (drbg
->lock
== NULL
) {
1137 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
1138 RAND_R_FAILED_TO_CREATE_LOCK
);
1148 * Get and set the EXDATA
1150 int RAND_DRBG_set_ex_data(RAND_DRBG
*drbg
, int idx
, void *arg
)
1152 return CRYPTO_set_ex_data(&drbg
->ex_data
, idx
, arg
);
1155 void *RAND_DRBG_get_ex_data(const RAND_DRBG
*drbg
, int idx
)
1157 return CRYPTO_get_ex_data(&drbg
->ex_data
, idx
);
1162 * The following functions provide a RAND_METHOD that works on the
1163 * global DRBG. They lock.
1167 * Allocates a new global DRBG on the secure heap (if enabled) and
1168 * initializes it with default settings.
1170 * Returns a pointer to the new DRBG instance on success, NULL on failure.
1172 static RAND_DRBG
*drbg_setup(OPENSSL_CTX
*ctx
, RAND_DRBG
*parent
, int drbg_type
)
1176 drbg
= RAND_DRBG_secure_new_ex(ctx
, rand_drbg_type
[drbg_type
],
1177 rand_drbg_flags
[drbg_type
], parent
);
1181 /* Only the master DRBG needs to have a lock */
1182 if (parent
== NULL
&& rand_drbg_enable_locking(drbg
) == 0)
1185 /* enable seed propagation */
1186 tsan_store(&drbg
->reseed_prop_counter
, 1);
1189 * Ignore instantiation error to support just-in-time instantiation.
1191 * The state of the drbg will be checked in RAND_DRBG_generate() and
1192 * an automatic recovery is attempted.
1194 (void)RAND_DRBG_instantiate(drbg
,
1195 (const unsigned char *) ossl_pers_string
,
1196 sizeof(ossl_pers_string
) - 1);
1200 RAND_DRBG_free(drbg
);
1204 static void drbg_delete_thread_state(void *arg
)
1206 OPENSSL_CTX
*ctx
= arg
;
1207 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1212 drbg
= CRYPTO_THREAD_get_local(&dgbl
->public_drbg
);
1213 CRYPTO_THREAD_set_local(&dgbl
->public_drbg
, NULL
);
1214 RAND_DRBG_free(drbg
);
1216 drbg
= CRYPTO_THREAD_get_local(&dgbl
->private_drbg
);
1217 CRYPTO_THREAD_set_local(&dgbl
->private_drbg
, NULL
);
1218 RAND_DRBG_free(drbg
);
1221 /* Implements the default OpenSSL RAND_bytes() method */
1222 static int drbg_bytes(unsigned char *out
, int count
)
1225 RAND_DRBG
*drbg
= RAND_DRBG_get0_public();
1230 ret
= RAND_DRBG_bytes(drbg
, out
, count
);
1236 * Calculates the minimum length of a full entropy buffer
1237 * which is necessary to seed (i.e. instantiate) the DRBG
1240 size_t rand_drbg_seedlen(RAND_DRBG
*drbg
)
1243 * If no os entropy source is available then RAND_seed(buffer, bufsize)
1244 * is expected to succeed if and only if the buffer length satisfies
1245 * the following requirements, which follow from the calculations
1246 * in RAND_DRBG_instantiate().
1248 size_t min_entropy
= drbg
->strength
;
1249 size_t min_entropylen
= drbg
->min_entropylen
;
1252 * Extra entropy for the random nonce in the absence of a
1253 * get_nonce callback, see comment in RAND_DRBG_instantiate().
1255 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
== NULL
) {
1256 min_entropy
+= drbg
->strength
/ 2;
1257 min_entropylen
+= drbg
->min_noncelen
;
1261 * Convert entropy requirement from bits to bytes
1262 * (dividing by 8 without rounding upwards, because
1263 * all entropy requirements are divisible by 8).
1267 /* Return a value that satisfies both requirements */
1268 return min_entropy
> min_entropylen
? min_entropy
: min_entropylen
;
1271 /* Implements the default OpenSSL RAND_add() method */
1272 static int drbg_add(const void *buf
, int num
, double randomness
)
1275 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
1282 if (num
< 0 || randomness
< 0.0)
1285 rand_drbg_lock(drbg
);
1286 seedlen
= rand_drbg_seedlen(drbg
);
1288 buflen
= (size_t)num
;
1292 * NIST SP-800-90A mandates that entropy *shall not* be provided
1293 * by the consuming application. By setting the randomness to zero,
1294 * we ensure that the buffer contents will be added to the internal
1295 * state of the DRBG only as additional data.
1297 * (NIST SP-800-90Ar1, Sections 9.1 and 9.2)
1301 if (buflen
< seedlen
|| randomness
< (double) seedlen
) {
1302 #if defined(OPENSSL_RAND_SEED_NONE)
1304 * If no os entropy source is available, a reseeding will fail
1305 * inevitably. So we use a trick to mix the buffer contents into
1306 * the DRBG state without forcing a reseeding: we generate a
1307 * dummy random byte, using the buffer content as additional data.
1308 * Note: This won't work with RAND_DRBG_FLAG_CTR_NO_DF.
1310 unsigned char dummy
[1];
1312 ret
= RAND_DRBG_generate(drbg
, dummy
, sizeof(dummy
), 0, buf
, buflen
);
1313 rand_drbg_unlock(drbg
);
1317 * If an os entropy source is available then we declare the buffer content
1318 * as additional data by setting randomness to zero and trigger a regular
1325 if (randomness
> (double)seedlen
) {
1327 * The purpose of this check is to bound |randomness| by a
1328 * relatively small value in order to prevent an integer
1329 * overflow when multiplying by 8 in the rand_drbg_restart()
1330 * call below. Note that randomness is measured in bytes,
1331 * not bits, so this value corresponds to eight times the
1332 * security strength.
1334 randomness
= (double)seedlen
;
1337 ret
= rand_drbg_restart(drbg
, buf
, buflen
, (size_t)(8 * randomness
));
1338 rand_drbg_unlock(drbg
);
1343 /* Implements the default OpenSSL RAND_seed() method */
1344 static int drbg_seed(const void *buf
, int num
)
1346 return drbg_add(buf
, num
, num
);
1349 /* Implements the default OpenSSL RAND_status() method */
1350 static int drbg_status(void)
1353 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
1358 rand_drbg_lock(drbg
);
1359 ret
= drbg
->state
== DRBG_READY
? 1 : 0;
1360 rand_drbg_unlock(drbg
);
1365 * Get the master DRBG.
1366 * Returns pointer to the DRBG on success, NULL on failure.
1369 RAND_DRBG
*OPENSSL_CTX_get0_master_drbg(OPENSSL_CTX
*ctx
)
1371 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1376 return dgbl
->master_drbg
;
1379 RAND_DRBG
*RAND_DRBG_get0_master(void)
1381 return OPENSSL_CTX_get0_master_drbg(NULL
);
1385 * Get the public DRBG.
1386 * Returns pointer to the DRBG on success, NULL on failure.
1388 RAND_DRBG
*OPENSSL_CTX_get0_public_drbg(OPENSSL_CTX
*ctx
)
1390 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1396 drbg
= CRYPTO_THREAD_get_local(&dgbl
->public_drbg
);
1398 ctx
= openssl_ctx_get_concrete(ctx
);
1400 * If the private_drbg is also NULL then this is the first time we've
1403 if (CRYPTO_THREAD_get_local(&dgbl
->private_drbg
) == NULL
1404 && !ossl_init_thread_start(NULL
, ctx
, drbg_delete_thread_state
))
1406 drbg
= drbg_setup(ctx
, dgbl
->master_drbg
, RAND_DRBG_TYPE_PUBLIC
);
1407 CRYPTO_THREAD_set_local(&dgbl
->public_drbg
, drbg
);
1412 RAND_DRBG
*RAND_DRBG_get0_public(void)
1414 return OPENSSL_CTX_get0_public_drbg(NULL
);
1418 * Get the private DRBG.
1419 * Returns pointer to the DRBG on success, NULL on failure.
1421 RAND_DRBG
*OPENSSL_CTX_get0_private_drbg(OPENSSL_CTX
*ctx
)
1423 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1429 drbg
= CRYPTO_THREAD_get_local(&dgbl
->private_drbg
);
1431 ctx
= openssl_ctx_get_concrete(ctx
);
1433 * If the public_drbg is also NULL then this is the first time we've
1436 if (CRYPTO_THREAD_get_local(&dgbl
->public_drbg
) == NULL
1437 && !ossl_init_thread_start(NULL
, ctx
, drbg_delete_thread_state
))
1439 drbg
= drbg_setup(ctx
, dgbl
->master_drbg
, RAND_DRBG_TYPE_PRIVATE
);
1440 CRYPTO_THREAD_set_local(&dgbl
->private_drbg
, drbg
);
1445 RAND_DRBG
*RAND_DRBG_get0_private(void)
1447 return OPENSSL_CTX_get0_private_drbg(NULL
);
1450 RAND_METHOD rand_meth
= {
1459 RAND_METHOD
*RAND_OpenSSL(void)