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
));
163 * We need to ensure that base libcrypto thread handling has been
166 OPENSSL_init_crypto(0, NULL
);
169 if (!CRYPTO_THREAD_init_local(&dgbl
->private_drbg
, NULL
))
172 if (!CRYPTO_THREAD_init_local(&dgbl
->public_drbg
, NULL
))
175 dgbl
->master_drbg
= drbg_setup(libctx
, NULL
, RAND_DRBG_TYPE_MASTER
);
176 if (dgbl
->master_drbg
== NULL
)
182 CRYPTO_THREAD_cleanup_local(&dgbl
->public_drbg
);
184 CRYPTO_THREAD_cleanup_local(&dgbl
->private_drbg
);
190 static void drbg_ossl_ctx_free(void *vdgbl
)
192 DRBG_GLOBAL
*dgbl
= vdgbl
;
194 RAND_DRBG_free(dgbl
->master_drbg
);
195 CRYPTO_THREAD_cleanup_local(&dgbl
->private_drbg
);
196 CRYPTO_THREAD_cleanup_local(&dgbl
->public_drbg
);
201 static const OPENSSL_CTX_METHOD drbg_ossl_ctx_method
= {
207 * drbg_ossl_ctx_new() calls drgb_setup() which calls rand_drbg_get_nonce()
208 * which needs to get the rand_nonce_lock out of the OPENSSL_CTX...but since
209 * drbg_ossl_ctx_new() hasn't finished running yet we need the rand_nonce_lock
210 * to be in a different global data object. Otherwise we will go into an
211 * infinite recursion loop.
213 static void *drbg_nonce_ossl_ctx_new(OPENSSL_CTX
*libctx
)
215 DRBG_NONCE_GLOBAL
*dngbl
= OPENSSL_zalloc(sizeof(*dngbl
));
220 dngbl
->rand_nonce_lock
= CRYPTO_THREAD_lock_new();
221 if (dngbl
->rand_nonce_lock
== NULL
) {
229 static void drbg_nonce_ossl_ctx_free(void *vdngbl
)
231 DRBG_NONCE_GLOBAL
*dngbl
= vdngbl
;
233 CRYPTO_THREAD_lock_free(dngbl
->rand_nonce_lock
);
238 static const OPENSSL_CTX_METHOD drbg_nonce_ossl_ctx_method
= {
239 drbg_nonce_ossl_ctx_new
,
240 drbg_nonce_ossl_ctx_free
,
243 static DRBG_GLOBAL
*drbg_get_global(OPENSSL_CTX
*libctx
)
245 return openssl_ctx_get_data(libctx
, OPENSSL_CTX_DRBG_INDEX
,
246 &drbg_ossl_ctx_method
);
249 /* Implements the get_nonce() callback (see RAND_DRBG_set_callbacks()) */
250 size_t rand_drbg_get_nonce(RAND_DRBG
*drbg
,
251 unsigned char **pout
,
252 int entropy
, size_t min_len
, size_t max_len
)
256 DRBG_NONCE_GLOBAL
*dngbl
257 = openssl_ctx_get_data(drbg
->libctx
, OPENSSL_CTX_DRBG_NONCE_INDEX
,
258 &drbg_nonce_ossl_ctx_method
);
267 memset(&data
, 0, sizeof(data
));
268 pool
= rand_pool_new(0, min_len
, max_len
);
272 if (rand_pool_add_nonce_data(pool
) == 0)
275 data
.instance
= drbg
;
276 CRYPTO_atomic_add(&dngbl
->rand_nonce_count
, 1, &data
.count
,
277 dngbl
->rand_nonce_lock
);
279 if (rand_pool_add(pool
, (unsigned char *)&data
, sizeof(data
), 0) == 0)
282 ret
= rand_pool_length(pool
);
283 *pout
= rand_pool_detach(pool
);
286 rand_pool_free(pool
);
292 * Implements the cleanup_nonce() callback (see RAND_DRBG_set_callbacks())
295 void rand_drbg_cleanup_nonce(RAND_DRBG
*drbg
,
296 unsigned char *out
, size_t outlen
)
298 OPENSSL_secure_clear_free(out
, outlen
);
302 * Set/initialize |drbg| to be of type |type|, with optional |flags|.
304 * If |type| and |flags| are zero, use the defaults
306 * Returns 1 on success, 0 on failure.
308 int RAND_DRBG_set(RAND_DRBG
*drbg
, int type
, unsigned int flags
)
312 if (type
== 0 && flags
== 0) {
313 type
= rand_drbg_type
[RAND_DRBG_TYPE_MASTER
];
314 flags
= rand_drbg_flags
[RAND_DRBG_TYPE_MASTER
];
317 /* If set is called multiple times - clear the old one */
318 if (drbg
->type
!= 0 && (type
!= drbg
->type
|| flags
!= drbg
->flags
)) {
319 drbg
->meth
->uninstantiate(drbg
);
320 rand_pool_free(drbg
->adin_pool
);
321 drbg
->adin_pool
= NULL
;
324 drbg
->state
= DRBG_UNINITIALISED
;
329 /* Uninitialized; that's okay. */
332 } else if (is_ctr(type
)) {
333 ret
= drbg_ctr_init(drbg
);
334 } else if (is_digest(type
)) {
335 if (flags
& RAND_DRBG_FLAG_HMAC
)
336 ret
= drbg_hmac_init(drbg
);
338 ret
= drbg_hash_init(drbg
);
343 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
348 drbg
->state
= DRBG_ERROR
;
349 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_ERROR_INITIALISING_DRBG
);
355 * Set/initialize default |type| and |flag| for new drbg instances.
357 * Returns 1 on success, 0 on failure.
359 int RAND_DRBG_set_defaults(int type
, unsigned int flags
)
362 if (!(is_digest(type
) || is_ctr(type
))) {
363 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
367 if ((flags
& ~rand_drbg_used_flags
) != 0) {
368 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS
, RAND_R_UNSUPPORTED_DRBG_FLAGS
);
372 all
= ((flags
& RAND_DRBG_TYPE_FLAGS
) == 0);
373 if (all
|| (flags
& RAND_DRBG_FLAG_MASTER
) != 0) {
374 rand_drbg_type
[RAND_DRBG_TYPE_MASTER
] = type
;
375 rand_drbg_flags
[RAND_DRBG_TYPE_MASTER
] = flags
| RAND_DRBG_FLAG_MASTER
;
377 if (all
|| (flags
& RAND_DRBG_FLAG_PUBLIC
) != 0) {
378 rand_drbg_type
[RAND_DRBG_TYPE_PUBLIC
] = type
;
379 rand_drbg_flags
[RAND_DRBG_TYPE_PUBLIC
] = flags
| RAND_DRBG_FLAG_PUBLIC
;
381 if (all
|| (flags
& RAND_DRBG_FLAG_PRIVATE
) != 0) {
382 rand_drbg_type
[RAND_DRBG_TYPE_PRIVATE
] = type
;
383 rand_drbg_flags
[RAND_DRBG_TYPE_PRIVATE
] = flags
| RAND_DRBG_FLAG_PRIVATE
;
390 * Allocate memory and initialize a new DRBG. The DRBG is allocated on
391 * the secure heap if |secure| is nonzero and the secure heap is enabled.
392 * The |parent|, if not NULL, will be used as random source for reseeding.
394 * Returns a pointer to the new DRBG instance on success, NULL on failure.
396 static RAND_DRBG
*rand_drbg_new(OPENSSL_CTX
*ctx
,
402 RAND_DRBG
*drbg
= secure
? OPENSSL_secure_zalloc(sizeof(*drbg
))
403 : OPENSSL_zalloc(sizeof(*drbg
));
406 RANDerr(RAND_F_RAND_DRBG_NEW
, ERR_R_MALLOC_FAILURE
);
411 drbg
->secure
= secure
&& CRYPTO_secure_allocated(drbg
);
412 drbg
->fork_count
= rand_fork_count
;
413 drbg
->parent
= parent
;
415 if (parent
== NULL
) {
417 drbg
->get_entropy
= rand_crngt_get_entropy
;
418 drbg
->cleanup_entropy
= rand_crngt_cleanup_entropy
;
420 drbg
->get_entropy
= rand_drbg_get_entropy
;
421 drbg
->cleanup_entropy
= rand_drbg_cleanup_entropy
;
423 #ifndef RAND_DRBG_GET_RANDOM_NONCE
424 drbg
->get_nonce
= rand_drbg_get_nonce
;
425 drbg
->cleanup_nonce
= rand_drbg_cleanup_nonce
;
428 drbg
->reseed_interval
= master_reseed_interval
;
429 drbg
->reseed_time_interval
= master_reseed_time_interval
;
431 drbg
->get_entropy
= rand_drbg_get_entropy
;
432 drbg
->cleanup_entropy
= rand_drbg_cleanup_entropy
;
434 * Do not provide nonce callbacks, the child DRBGs will
435 * obtain their nonce using random bits from the parent.
438 drbg
->reseed_interval
= slave_reseed_interval
;
439 drbg
->reseed_time_interval
= slave_reseed_time_interval
;
442 if (RAND_DRBG_set(drbg
, type
, flags
) == 0)
445 if (parent
!= NULL
) {
446 rand_drbg_lock(parent
);
447 if (drbg
->strength
> parent
->strength
) {
449 * We currently don't support the algorithm from NIST SP 800-90C
450 * 10.1.2 to use a weaker DRBG as source
452 rand_drbg_unlock(parent
);
453 RANDerr(RAND_F_RAND_DRBG_NEW
, RAND_R_PARENT_STRENGTH_TOO_WEAK
);
456 rand_drbg_unlock(parent
);
462 RAND_DRBG_free(drbg
);
467 RAND_DRBG
*RAND_DRBG_new_ex(OPENSSL_CTX
*ctx
, int type
, unsigned int flags
,
470 return rand_drbg_new(ctx
, 0, type
, flags
, parent
);
473 RAND_DRBG
*RAND_DRBG_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
475 return RAND_DRBG_new_ex(NULL
, type
, flags
, parent
);
478 RAND_DRBG
*RAND_DRBG_secure_new_ex(OPENSSL_CTX
*ctx
, int type
,
479 unsigned int flags
, RAND_DRBG
*parent
)
481 return rand_drbg_new(ctx
, 1, type
, flags
, parent
);
484 RAND_DRBG
*RAND_DRBG_secure_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
486 return RAND_DRBG_secure_new_ex(NULL
, type
, flags
, parent
);
489 * Uninstantiate |drbg| and free all memory.
491 void RAND_DRBG_free(RAND_DRBG
*drbg
)
496 if (drbg
->meth
!= NULL
)
497 drbg
->meth
->uninstantiate(drbg
);
498 rand_pool_free(drbg
->adin_pool
);
499 CRYPTO_THREAD_lock_free(drbg
->lock
);
500 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG
, drbg
, &drbg
->ex_data
);
503 OPENSSL_secure_clear_free(drbg
, sizeof(*drbg
));
505 OPENSSL_clear_free(drbg
, sizeof(*drbg
));
509 * Instantiate |drbg|, after it has been initialized. Use |pers| and
510 * |perslen| as prediction-resistance input.
512 * Requires that drbg->lock is already locked for write, if non-null.
514 * Returns 1 on success, 0 on failure.
516 int RAND_DRBG_instantiate(RAND_DRBG
*drbg
,
517 const unsigned char *pers
, size_t perslen
)
519 unsigned char *nonce
= NULL
, *entropy
= NULL
;
520 size_t noncelen
= 0, entropylen
= 0;
521 size_t min_entropy
= drbg
->strength
;
522 size_t min_entropylen
= drbg
->min_entropylen
;
523 size_t max_entropylen
= drbg
->max_entropylen
;
525 if (perslen
> drbg
->max_perslen
) {
526 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
527 RAND_R_PERSONALISATION_STRING_TOO_LONG
);
531 if (drbg
->meth
== NULL
) {
532 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
533 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
537 if (drbg
->state
!= DRBG_UNINITIALISED
) {
538 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
539 drbg
->state
== DRBG_ERROR
? RAND_R_IN_ERROR_STATE
540 : RAND_R_ALREADY_INSTANTIATED
);
544 drbg
->state
= DRBG_ERROR
;
547 * NIST SP800-90Ar1 section 9.1 says you can combine getting the entropy
548 * and nonce in 1 call by increasing the entropy with 50% and increasing
549 * the minimum length to accomadate the length of the nonce.
550 * We do this in case a nonce is require and get_nonce is NULL.
552 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
== NULL
) {
553 min_entropy
+= drbg
->strength
/ 2;
554 min_entropylen
+= drbg
->min_noncelen
;
555 max_entropylen
+= drbg
->max_noncelen
;
558 drbg
->reseed_next_counter
= tsan_load(&drbg
->reseed_prop_counter
);
559 if (drbg
->reseed_next_counter
) {
560 drbg
->reseed_next_counter
++;
561 if(!drbg
->reseed_next_counter
)
562 drbg
->reseed_next_counter
= 1;
565 if (drbg
->get_entropy
!= NULL
)
566 entropylen
= drbg
->get_entropy(drbg
, &entropy
, min_entropy
,
567 min_entropylen
, max_entropylen
, 0);
568 if (entropylen
< min_entropylen
569 || entropylen
> max_entropylen
) {
570 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
574 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
!= NULL
) {
575 noncelen
= drbg
->get_nonce(drbg
, &nonce
, drbg
->strength
/ 2,
576 drbg
->min_noncelen
, drbg
->max_noncelen
);
577 if (noncelen
< drbg
->min_noncelen
|| noncelen
> drbg
->max_noncelen
) {
578 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_NONCE
);
583 if (!drbg
->meth
->instantiate(drbg
, entropy
, entropylen
,
584 nonce
, noncelen
, pers
, perslen
)) {
585 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_INSTANTIATING_DRBG
);
589 drbg
->state
= DRBG_READY
;
590 drbg
->reseed_gen_counter
= 1;
591 drbg
->reseed_time
= time(NULL
);
592 tsan_store(&drbg
->reseed_prop_counter
, drbg
->reseed_next_counter
);
595 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
596 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
597 if (nonce
!= NULL
&& drbg
->cleanup_nonce
!= NULL
)
598 drbg
->cleanup_nonce(drbg
, nonce
, noncelen
);
599 if (drbg
->state
== DRBG_READY
)
605 * Uninstantiate |drbg|. Must be instantiated before it can be used.
607 * Requires that drbg->lock is already locked for write, if non-null.
609 * Returns 1 on success, 0 on failure.
611 int RAND_DRBG_uninstantiate(RAND_DRBG
*drbg
)
613 int index
= -1, type
, flags
;
614 if (drbg
->meth
== NULL
) {
615 drbg
->state
= DRBG_ERROR
;
616 RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE
,
617 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
621 /* Clear the entire drbg->ctr struct, then reset some important
622 * members of the drbg->ctr struct (e.g. keysize, df_ks) to their
625 drbg
->meth
->uninstantiate(drbg
);
627 /* The reset uses the default values for type and flags */
628 if (drbg
->flags
& RAND_DRBG_FLAG_MASTER
)
629 index
= RAND_DRBG_TYPE_MASTER
;
630 else if (drbg
->flags
& RAND_DRBG_FLAG_PRIVATE
)
631 index
= RAND_DRBG_TYPE_PRIVATE
;
632 else if (drbg
->flags
& RAND_DRBG_FLAG_PUBLIC
)
633 index
= RAND_DRBG_TYPE_PUBLIC
;
636 flags
= rand_drbg_flags
[index
];
637 type
= rand_drbg_type
[index
];
642 return RAND_DRBG_set(drbg
, type
, flags
);
646 * Reseed |drbg|, mixing in the specified data
648 * Requires that drbg->lock is already locked for write, if non-null.
650 * Returns 1 on success, 0 on failure.
652 int RAND_DRBG_reseed(RAND_DRBG
*drbg
,
653 const unsigned char *adin
, size_t adinlen
,
654 int prediction_resistance
)
656 unsigned char *entropy
= NULL
;
657 size_t entropylen
= 0;
659 if (drbg
->state
== DRBG_ERROR
) {
660 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_IN_ERROR_STATE
);
663 if (drbg
->state
== DRBG_UNINITIALISED
) {
664 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_NOT_INSTANTIATED
);
670 } else if (adinlen
> drbg
->max_adinlen
) {
671 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
675 drbg
->state
= DRBG_ERROR
;
677 drbg
->reseed_next_counter
= tsan_load(&drbg
->reseed_prop_counter
);
678 if (drbg
->reseed_next_counter
) {
679 drbg
->reseed_next_counter
++;
680 if(!drbg
->reseed_next_counter
)
681 drbg
->reseed_next_counter
= 1;
684 if (drbg
->get_entropy
!= NULL
)
685 entropylen
= drbg
->get_entropy(drbg
, &entropy
, drbg
->strength
,
686 drbg
->min_entropylen
,
687 drbg
->max_entropylen
,
688 prediction_resistance
);
689 if (entropylen
< drbg
->min_entropylen
690 || entropylen
> drbg
->max_entropylen
) {
691 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
695 if (!drbg
->meth
->reseed(drbg
, entropy
, entropylen
, adin
, adinlen
))
698 drbg
->state
= DRBG_READY
;
699 drbg
->reseed_gen_counter
= 1;
700 drbg
->reseed_time
= time(NULL
);
701 tsan_store(&drbg
->reseed_prop_counter
, drbg
->reseed_next_counter
);
704 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
705 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
706 if (drbg
->state
== DRBG_READY
)
712 * Restart |drbg|, using the specified entropy or additional input
714 * Tries its best to get the drbg instantiated by all means,
715 * regardless of its current state.
717 * Optionally, a |buffer| of |len| random bytes can be passed,
718 * which is assumed to contain at least |entropy| bits of entropy.
720 * If |entropy| > 0, the buffer content is used as entropy input.
722 * If |entropy| == 0, the buffer content is used as additional input
724 * Returns 1 on success, 0 on failure.
726 * This function is used internally only.
728 int rand_drbg_restart(RAND_DRBG
*drbg
,
729 const unsigned char *buffer
, size_t len
, size_t entropy
)
732 const unsigned char *adin
= NULL
;
735 if (drbg
->seed_pool
!= NULL
) {
736 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
737 drbg
->state
= DRBG_ERROR
;
738 rand_pool_free(drbg
->seed_pool
);
739 drbg
->seed_pool
= NULL
;
743 if (buffer
!= NULL
) {
745 if (drbg
->max_entropylen
< len
) {
746 RANDerr(RAND_F_RAND_DRBG_RESTART
,
747 RAND_R_ENTROPY_INPUT_TOO_LONG
);
748 drbg
->state
= DRBG_ERROR
;
752 if (entropy
> 8 * len
) {
753 RANDerr(RAND_F_RAND_DRBG_RESTART
, RAND_R_ENTROPY_OUT_OF_RANGE
);
754 drbg
->state
= DRBG_ERROR
;
758 /* will be picked up by the rand_drbg_get_entropy() callback */
759 drbg
->seed_pool
= rand_pool_attach(buffer
, len
, entropy
);
760 if (drbg
->seed_pool
== NULL
)
763 if (drbg
->max_adinlen
< len
) {
764 RANDerr(RAND_F_RAND_DRBG_RESTART
,
765 RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
766 drbg
->state
= DRBG_ERROR
;
774 /* repair error state */
775 if (drbg
->state
== DRBG_ERROR
)
776 RAND_DRBG_uninstantiate(drbg
);
778 /* repair uninitialized state */
779 if (drbg
->state
== DRBG_UNINITIALISED
) {
780 /* reinstantiate drbg */
781 RAND_DRBG_instantiate(drbg
,
782 (const unsigned char *) ossl_pers_string
,
783 sizeof(ossl_pers_string
) - 1);
784 /* already reseeded. prevent second reseeding below */
785 reseeded
= (drbg
->state
== DRBG_READY
);
788 /* refresh current state if entropy or additional input has been provided */
789 if (drbg
->state
== DRBG_READY
) {
792 * mix in additional input without reseeding
794 * Similar to RAND_DRBG_reseed(), but the provided additional
795 * data |adin| is mixed into the current state without pulling
796 * entropy from the trusted entropy source using get_entropy().
797 * This is not a reseeding in the strict sense of NIST SP 800-90A.
799 drbg
->meth
->reseed(drbg
, adin
, adinlen
, NULL
, 0);
800 } else if (reseeded
== 0) {
801 /* do a full reseeding if it has not been done yet above */
802 RAND_DRBG_reseed(drbg
, NULL
, 0, 0);
806 rand_pool_free(drbg
->seed_pool
);
807 drbg
->seed_pool
= NULL
;
809 return drbg
->state
== DRBG_READY
;
813 * Generate |outlen| bytes into the buffer at |out|. Reseed if we need
814 * to or if |prediction_resistance| is set. Additional input can be
815 * sent in |adin| and |adinlen|.
817 * Requires that drbg->lock is already locked for write, if non-null.
819 * Returns 1 on success, 0 on failure.
822 int RAND_DRBG_generate(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
,
823 int prediction_resistance
,
824 const unsigned char *adin
, size_t adinlen
)
826 int reseed_required
= 0;
828 if (drbg
->state
!= DRBG_READY
) {
829 /* try to recover from previous errors */
830 rand_drbg_restart(drbg
, NULL
, 0, 0);
832 if (drbg
->state
== DRBG_ERROR
) {
833 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_IN_ERROR_STATE
);
836 if (drbg
->state
== DRBG_UNINITIALISED
) {
837 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_NOT_INSTANTIATED
);
842 if (outlen
> drbg
->max_request
) {
843 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG
);
846 if (adinlen
> drbg
->max_adinlen
) {
847 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
851 if (drbg
->fork_count
!= rand_fork_count
) {
852 drbg
->fork_count
= rand_fork_count
;
856 if (drbg
->reseed_interval
> 0) {
857 if (drbg
->reseed_gen_counter
> drbg
->reseed_interval
)
860 if (drbg
->reseed_time_interval
> 0) {
861 time_t now
= time(NULL
);
862 if (now
< drbg
->reseed_time
863 || now
- drbg
->reseed_time
>= drbg
->reseed_time_interval
)
866 if (drbg
->parent
!= NULL
) {
867 unsigned int reseed_counter
= tsan_load(&drbg
->reseed_prop_counter
);
868 if (reseed_counter
> 0
869 && tsan_load(&drbg
->parent
->reseed_prop_counter
)
874 if (reseed_required
|| prediction_resistance
) {
875 if (!RAND_DRBG_reseed(drbg
, adin
, adinlen
, prediction_resistance
)) {
876 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_RESEED_ERROR
);
883 if (!drbg
->meth
->generate(drbg
, out
, outlen
, adin
, adinlen
)) {
884 drbg
->state
= DRBG_ERROR
;
885 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_GENERATE_ERROR
);
889 drbg
->reseed_gen_counter
++;
895 * Generates |outlen| random bytes and stores them in |out|. It will
896 * using the given |drbg| to generate the bytes.
898 * Requires that drbg->lock is already locked for write, if non-null.
900 * Returns 1 on success 0 on failure.
902 int RAND_DRBG_bytes(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
)
904 unsigned char *additional
= NULL
;
905 size_t additional_len
;
909 if (drbg
->adin_pool
== NULL
) {
912 drbg
->adin_pool
= rand_pool_new(0, 0, drbg
->max_adinlen
);
913 if (drbg
->adin_pool
== NULL
)
917 additional_len
= rand_drbg_get_additional_data(drbg
->adin_pool
,
920 for ( ; outlen
> 0; outlen
-= chunk
, out
+= chunk
) {
922 if (chunk
> drbg
->max_request
)
923 chunk
= drbg
->max_request
;
924 ret
= RAND_DRBG_generate(drbg
, out
, chunk
, 0, additional
, additional_len
);
931 if (additional
!= NULL
)
932 rand_drbg_cleanup_additional_data(drbg
->adin_pool
, additional
);
938 * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
940 * Setting the callbacks is allowed only if the drbg has not been
941 * initialized yet. Otherwise, the operation will fail.
943 * Returns 1 on success, 0 on failure.
945 int RAND_DRBG_set_callbacks(RAND_DRBG
*drbg
,
946 RAND_DRBG_get_entropy_fn get_entropy
,
947 RAND_DRBG_cleanup_entropy_fn cleanup_entropy
,
948 RAND_DRBG_get_nonce_fn get_nonce
,
949 RAND_DRBG_cleanup_nonce_fn cleanup_nonce
)
951 if (drbg
->state
!= DRBG_UNINITIALISED
952 || drbg
->parent
!= NULL
)
954 drbg
->get_entropy
= get_entropy
;
955 drbg
->cleanup_entropy
= cleanup_entropy
;
956 drbg
->get_nonce
= get_nonce
;
957 drbg
->cleanup_nonce
= cleanup_nonce
;
962 * Set the reseed interval.
964 * The drbg will reseed automatically whenever the number of generate
965 * requests exceeds the given reseed interval. If the reseed interval
966 * is 0, then this feature is disabled.
968 * Returns 1 on success, 0 on failure.
970 int RAND_DRBG_set_reseed_interval(RAND_DRBG
*drbg
, unsigned int interval
)
972 if (interval
> MAX_RESEED_INTERVAL
)
974 drbg
->reseed_interval
= interval
;
979 * Set the reseed time interval.
981 * The drbg will reseed automatically whenever the time elapsed since
982 * the last reseeding exceeds the given reseed time interval. For safety,
983 * a reseeding will also occur if the clock has been reset to a smaller
986 * Returns 1 on success, 0 on failure.
988 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG
*drbg
, time_t interval
)
990 if (interval
> MAX_RESEED_TIME_INTERVAL
)
992 drbg
->reseed_time_interval
= interval
;
997 * Set the default values for reseed (time) intervals of new DRBG instances
999 * The default values can be set independently for master DRBG instances
1000 * (without a parent) and slave DRBG instances (with parent).
1002 * Returns 1 on success, 0 on failure.
1005 int RAND_DRBG_set_reseed_defaults(
1006 unsigned int _master_reseed_interval
,
1007 unsigned int _slave_reseed_interval
,
1008 time_t _master_reseed_time_interval
,
1009 time_t _slave_reseed_time_interval
1012 if (_master_reseed_interval
> MAX_RESEED_INTERVAL
1013 || _slave_reseed_interval
> MAX_RESEED_INTERVAL
)
1016 if (_master_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
1017 || _slave_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
)
1020 master_reseed_interval
= _master_reseed_interval
;
1021 slave_reseed_interval
= _slave_reseed_interval
;
1023 master_reseed_time_interval
= _master_reseed_time_interval
;
1024 slave_reseed_time_interval
= _slave_reseed_time_interval
;
1030 * Locks the given drbg. Locking a drbg which does not have locking
1031 * enabled is considered a successful no-op.
1033 * Returns 1 on success, 0 on failure.
1035 int rand_drbg_lock(RAND_DRBG
*drbg
)
1037 if (drbg
->lock
!= NULL
)
1038 return CRYPTO_THREAD_write_lock(drbg
->lock
);
1044 * Unlocks the given drbg. Unlocking a drbg which does not have locking
1045 * enabled is considered a successful no-op.
1047 * Returns 1 on success, 0 on failure.
1049 int rand_drbg_unlock(RAND_DRBG
*drbg
)
1051 if (drbg
->lock
!= NULL
)
1052 return CRYPTO_THREAD_unlock(drbg
->lock
);
1058 * Enables locking for the given drbg
1060 * Locking can only be enabled if the random generator
1061 * is in the uninitialized state.
1063 * Returns 1 on success, 0 on failure.
1065 int rand_drbg_enable_locking(RAND_DRBG
*drbg
)
1067 if (drbg
->state
!= DRBG_UNINITIALISED
) {
1068 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
1069 RAND_R_DRBG_ALREADY_INITIALIZED
);
1073 if (drbg
->lock
== NULL
) {
1074 if (drbg
->parent
!= NULL
&& drbg
->parent
->lock
== NULL
) {
1075 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
1076 RAND_R_PARENT_LOCKING_NOT_ENABLED
);
1080 drbg
->lock
= CRYPTO_THREAD_lock_new();
1081 if (drbg
->lock
== NULL
) {
1082 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
1083 RAND_R_FAILED_TO_CREATE_LOCK
);
1092 * Get and set the EXDATA
1094 int RAND_DRBG_set_ex_data(RAND_DRBG
*drbg
, int idx
, void *arg
)
1096 return CRYPTO_set_ex_data(&drbg
->ex_data
, idx
, arg
);
1099 void *RAND_DRBG_get_ex_data(const RAND_DRBG
*drbg
, int idx
)
1101 return CRYPTO_get_ex_data(&drbg
->ex_data
, idx
);
1106 * The following functions provide a RAND_METHOD that works on the
1107 * global DRBG. They lock.
1111 * Allocates a new global DRBG on the secure heap (if enabled) and
1112 * initializes it with default settings.
1114 * Returns a pointer to the new DRBG instance on success, NULL on failure.
1116 static RAND_DRBG
*drbg_setup(OPENSSL_CTX
*ctx
, RAND_DRBG
*parent
, int drbg_type
)
1120 drbg
= RAND_DRBG_secure_new_ex(ctx
, rand_drbg_type
[drbg_type
],
1121 rand_drbg_flags
[drbg_type
], parent
);
1125 /* Only the master DRBG needs to have a lock */
1126 if (parent
== NULL
&& rand_drbg_enable_locking(drbg
) == 0)
1129 /* enable seed propagation */
1130 tsan_store(&drbg
->reseed_prop_counter
, 1);
1133 * Ignore instantiation error to support just-in-time instantiation.
1135 * The state of the drbg will be checked in RAND_DRBG_generate() and
1136 * an automatic recovery is attempted.
1138 (void)RAND_DRBG_instantiate(drbg
,
1139 (const unsigned char *) ossl_pers_string
,
1140 sizeof(ossl_pers_string
) - 1);
1144 RAND_DRBG_free(drbg
);
1148 static void drbg_delete_thread_state(void *arg
)
1150 OPENSSL_CTX
*ctx
= arg
;
1151 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1156 drbg
= CRYPTO_THREAD_get_local(&dgbl
->public_drbg
);
1157 CRYPTO_THREAD_set_local(&dgbl
->public_drbg
, NULL
);
1158 RAND_DRBG_free(drbg
);
1160 drbg
= CRYPTO_THREAD_get_local(&dgbl
->private_drbg
);
1161 CRYPTO_THREAD_set_local(&dgbl
->private_drbg
, NULL
);
1162 RAND_DRBG_free(drbg
);
1165 /* Implements the default OpenSSL RAND_bytes() method */
1166 static int drbg_bytes(unsigned char *out
, int count
)
1169 RAND_DRBG
*drbg
= RAND_DRBG_get0_public();
1174 ret
= RAND_DRBG_bytes(drbg
, out
, count
);
1180 * Calculates the minimum length of a full entropy buffer
1181 * which is necessary to seed (i.e. instantiate) the DRBG
1184 size_t rand_drbg_seedlen(RAND_DRBG
*drbg
)
1187 * If no os entropy source is available then RAND_seed(buffer, bufsize)
1188 * is expected to succeed if and only if the buffer length satisfies
1189 * the following requirements, which follow from the calculations
1190 * in RAND_DRBG_instantiate().
1192 size_t min_entropy
= drbg
->strength
;
1193 size_t min_entropylen
= drbg
->min_entropylen
;
1196 * Extra entropy for the random nonce in the absence of a
1197 * get_nonce callback, see comment in RAND_DRBG_instantiate().
1199 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
== NULL
) {
1200 min_entropy
+= drbg
->strength
/ 2;
1201 min_entropylen
+= drbg
->min_noncelen
;
1205 * Convert entropy requirement from bits to bytes
1206 * (dividing by 8 without rounding upwards, because
1207 * all entropy requirements are divisible by 8).
1211 /* Return a value that satisfies both requirements */
1212 return min_entropy
> min_entropylen
? min_entropy
: min_entropylen
;
1215 /* Implements the default OpenSSL RAND_add() method */
1216 static int drbg_add(const void *buf
, int num
, double randomness
)
1219 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
1226 if (num
< 0 || randomness
< 0.0)
1229 rand_drbg_lock(drbg
);
1230 seedlen
= rand_drbg_seedlen(drbg
);
1232 buflen
= (size_t)num
;
1236 * NIST SP-800-90A mandates that entropy *shall not* be provided
1237 * by the consuming application. By setting the randomness to zero,
1238 * we ensure that the buffer contents will be added to the internal
1239 * state of the DRBG only as additional data.
1241 * (NIST SP-800-90Ar1, Sections 9.1 and 9.2)
1245 if (buflen
< seedlen
|| randomness
< (double) seedlen
) {
1246 #if defined(OPENSSL_RAND_SEED_NONE)
1248 * If no os entropy source is available, a reseeding will fail
1249 * inevitably. So we use a trick to mix the buffer contents into
1250 * the DRBG state without forcing a reseeding: we generate a
1251 * dummy random byte, using the buffer content as additional data.
1252 * Note: This won't work with RAND_DRBG_FLAG_CTR_NO_DF.
1254 unsigned char dummy
[1];
1256 ret
= RAND_DRBG_generate(drbg
, dummy
, sizeof(dummy
), 0, buf
, buflen
);
1257 rand_drbg_unlock(drbg
);
1261 * If an os entropy source is available then we declare the buffer content
1262 * as additional data by setting randomness to zero and trigger a regular
1269 if (randomness
> (double)seedlen
) {
1271 * The purpose of this check is to bound |randomness| by a
1272 * relatively small value in order to prevent an integer
1273 * overflow when multiplying by 8 in the rand_drbg_restart()
1274 * call below. Note that randomness is measured in bytes,
1275 * not bits, so this value corresponds to eight times the
1276 * security strength.
1278 randomness
= (double)seedlen
;
1281 ret
= rand_drbg_restart(drbg
, buf
, buflen
, (size_t)(8 * randomness
));
1282 rand_drbg_unlock(drbg
);
1287 /* Implements the default OpenSSL RAND_seed() method */
1288 static int drbg_seed(const void *buf
, int num
)
1290 return drbg_add(buf
, num
, num
);
1293 /* Implements the default OpenSSL RAND_status() method */
1294 static int drbg_status(void)
1297 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
1302 rand_drbg_lock(drbg
);
1303 ret
= drbg
->state
== DRBG_READY
? 1 : 0;
1304 rand_drbg_unlock(drbg
);
1309 * Get the master DRBG.
1310 * Returns pointer to the DRBG on success, NULL on failure.
1313 RAND_DRBG
*OPENSSL_CTX_get0_master_drbg(OPENSSL_CTX
*ctx
)
1315 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1320 return dgbl
->master_drbg
;
1323 RAND_DRBG
*RAND_DRBG_get0_master(void)
1325 return OPENSSL_CTX_get0_master_drbg(NULL
);
1329 * Get the public DRBG.
1330 * Returns pointer to the DRBG on success, NULL on failure.
1332 RAND_DRBG
*OPENSSL_CTX_get0_public_drbg(OPENSSL_CTX
*ctx
)
1334 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1340 drbg
= CRYPTO_THREAD_get_local(&dgbl
->public_drbg
);
1342 ctx
= openssl_ctx_get_concrete(ctx
);
1343 if (!ossl_init_thread_start(NULL
, ctx
, drbg_delete_thread_state
))
1345 drbg
= drbg_setup(ctx
, dgbl
->master_drbg
, RAND_DRBG_TYPE_PUBLIC
);
1346 CRYPTO_THREAD_set_local(&dgbl
->public_drbg
, drbg
);
1351 RAND_DRBG
*RAND_DRBG_get0_public(void)
1353 return OPENSSL_CTX_get0_public_drbg(NULL
);
1357 * Get the private DRBG.
1358 * Returns pointer to the DRBG on success, NULL on failure.
1360 RAND_DRBG
*OPENSSL_CTX_get0_private_drbg(OPENSSL_CTX
*ctx
)
1362 DRBG_GLOBAL
*dgbl
= drbg_get_global(ctx
);
1368 drbg
= CRYPTO_THREAD_get_local(&dgbl
->private_drbg
);
1370 ctx
= openssl_ctx_get_concrete(ctx
);
1371 if (!ossl_init_thread_start(NULL
, ctx
, drbg_delete_thread_state
))
1373 drbg
= drbg_setup(ctx
, dgbl
->master_drbg
, RAND_DRBG_TYPE_PRIVATE
);
1374 CRYPTO_THREAD_set_local(&dgbl
->private_drbg
, drbg
);
1379 RAND_DRBG
*RAND_DRBG_get0_private(void)
1381 return OPENSSL_CTX_get0_private_drbg(NULL
);
1384 RAND_METHOD rand_meth
= {
1393 RAND_METHOD
*RAND_OpenSSL(void)