2 * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include <openssl/crypto.h>
12 #include <openssl/err.h>
13 #include <openssl/rand.h>
15 #include "internal/thread_once.h"
16 #include "internal/rand_int.h"
19 * Support framework for NIST SP 800-90A DRBG, AES-CTR mode.
20 * The RAND_DRBG is OpenSSL's pointer to an instance of the DRBG.
22 * The OpenSSL model is to have new and free functions, and that new
23 * does all initialization. That is not the NIST model, which has
24 * instantiation and un-instantiate, and re-use within a new/free
25 * lifecycle. (No doubt this comes from the desire to support hardware
26 * DRBG, where allocation of resources on something like an HSM is
27 * a much bigger deal than just re-setting an allocated resource.)
31 * THE THREE SHARED DRBGs
33 * There are three shared DRBGs (master, public and private), which are
34 * accessed concurrently by all threads.
38 * Not used directly by the application, only for reseeding the two other
39 * DRBGs. It reseeds itself by pulling either randomness from os entropy
40 * sources or by consuming randomnes which was added by RAND_add()
42 static RAND_DRBG
*drbg_master
;
46 * Used by default for generating random bytes using RAND_bytes().
48 static RAND_DRBG
*drbg_public
;
52 * Used by default for generating private keys using RAND_priv_bytes()
54 static RAND_DRBG
*drbg_private
;
58 * In addition there are DRBGs, which are not shared, but used only by a
59 * single thread at every time, for example the DRBGs which are owned by
60 * an SSL context. All DRBGs are organized in a hierarchical fashion
61 * with the <master> DRBG as root.
63 * This gives the following overall picture:
65 * <os entropy sources>
67 * RAND_add() ==> <master> \
68 * / \ | shared DRBGs (with locking)
69 * <public> <private> /
71 * <ssl> owned by an SSL context
75 * Before satisfying a generate request, a DRBG reseeds itself automatically,
76 * if one of the following two conditions holds:
78 * - the number of generate requests since the last reseeding exceeds a
79 * certain threshold, the so called |reseed_interval|. This behaviour
80 * can be disabled by setting the |reseed_interval| to 0.
82 * - the time elapsed since the last reseeding exceeds a certain time
83 * interval, the so called |reseed_time_interval|. This behaviour
84 * can be disabled by setting the |reseed_time_interval| to 0.
88 * For the three shared DRBGs (and only for these) there is another way to
89 * reseed them manually by calling RAND_seed() (or RAND_add() with a positive
90 * |randomness| argument). This will immediately reseed the <master> DRBG.
91 * The <public> and <private> DRBG will detect this on their next generate
92 * call and reseed, pulling randomness from <master>.
96 * The three shared DRBGs are intended to be used concurrently, so they
97 * support locking. The RAND methods take the locks automatically, so using
98 * the RAND api (in particular RAND_bytes() and RAND_priv_bytes()) is
99 * thread-safe. Note however that accessing the shared DRBGs directly via
100 * the RAND_DRBG interface is *not* thread-safe.
102 * All other DRBG instances don't support locking, because they are
103 * intendended to be used by a single thread. Instead of accessing a single
104 * DRBG instance concurrently from different threads, it is recommended to
105 * instantiate a separate DRBG instance per thread. Using the same shared
106 * DRBG (preferrably the public DRBG) as parent of DRBG instances on
107 * different threads is safe.
111 /* NIST SP 800-90A DRBG recommends the use of a personalization string. */
112 static const char ossl_pers_string
[] = "OpenSSL NIST SP 800-90A DRBG";
114 static CRYPTO_ONCE rand_drbg_init
= CRYPTO_ONCE_STATIC_INIT
;
116 static unsigned int master_reseed_interval
= MASTER_RESEED_INTERVAL
;
117 static unsigned int slave_reseed_interval
= SLAVE_RESEED_INTERVAL
;
119 static time_t master_reseed_time_interval
= MASTER_RESEED_TIME_INTERVAL
;
120 static time_t slave_reseed_time_interval
= SLAVE_RESEED_TIME_INTERVAL
;
122 static RAND_DRBG
*drbg_setup(RAND_DRBG
*parent
);
124 static RAND_DRBG
*rand_drbg_new(int secure
,
130 * Set/initialize |drbg| to be of type |nid|, with optional |flags|.
132 * Returns 1 on success, 0 on failure.
134 int RAND_DRBG_set(RAND_DRBG
*drbg
, int nid
, unsigned int flags
)
138 drbg
->state
= DRBG_UNINITIALISED
;
144 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
147 /* Uninitialized; that's okay. */
149 case NID_aes_128_ctr
:
150 case NID_aes_192_ctr
:
151 case NID_aes_256_ctr
:
152 ret
= drbg_ctr_init(drbg
);
157 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_ERROR_INITIALISING_DRBG
);
162 * Allocate memory and initialize a new DRBG. The DRBG is allocated on
163 * the secure heap if |secure| is nonzero and the secure heap is enabled.
164 * The |parent|, if not NULL, will be used as random source for reseeding.
166 * Returns a pointer to the new DRBG instance on success, NULL on failure.
168 static RAND_DRBG
*rand_drbg_new(int secure
,
173 RAND_DRBG
*drbg
= secure
?
174 OPENSSL_secure_zalloc(sizeof(*drbg
)) : OPENSSL_zalloc(sizeof(*drbg
));
177 RANDerr(RAND_F_RAND_DRBG_NEW
, ERR_R_MALLOC_FAILURE
);
181 drbg
->secure
= secure
&& CRYPTO_secure_allocated(drbg
);
182 drbg
->fork_count
= rand_fork_count
;
183 drbg
->parent
= parent
;
185 if (parent
== NULL
) {
186 drbg
->reseed_interval
= master_reseed_interval
;
187 drbg
->reseed_time_interval
= master_reseed_time_interval
;
189 drbg
->reseed_interval
= slave_reseed_interval
;
190 drbg
->reseed_time_interval
= slave_reseed_time_interval
;
193 if (RAND_DRBG_set(drbg
, type
, flags
) == 0)
196 if (parent
!= NULL
&& drbg
->strength
> parent
->strength
) {
198 * We currently don't support the algorithm from NIST SP 800-90C
199 * 10.1.2 to use a weaker DRBG as source
201 RANDerr(RAND_F_RAND_DRBG_NEW
, RAND_R_PARENT_STRENGTH_TOO_WEAK
);
205 if (!RAND_DRBG_set_callbacks(drbg
, rand_drbg_get_entropy
,
206 rand_drbg_cleanup_entropy
,
214 OPENSSL_secure_free(drbg
);
221 RAND_DRBG
*RAND_DRBG_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
223 return rand_drbg_new(0, type
, flags
, parent
);
226 RAND_DRBG
*RAND_DRBG_secure_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
228 return rand_drbg_new(1, type
, flags
, parent
);
232 * Uninstantiate |drbg| and free all memory.
234 void RAND_DRBG_free(RAND_DRBG
*drbg
)
239 if (drbg
->meth
!= NULL
)
240 drbg
->meth
->uninstantiate(drbg
);
241 CRYPTO_THREAD_lock_free(drbg
->lock
);
242 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG
, drbg
, &drbg
->ex_data
);
245 OPENSSL_secure_clear_free(drbg
, sizeof(*drbg
));
247 OPENSSL_clear_free(drbg
, sizeof(*drbg
));
251 * Instantiate |drbg|, after it has been initialized. Use |pers| and
252 * |perslen| as prediction-resistance input.
254 * Requires that drbg->lock is already locked for write, if non-null.
256 * Returns 1 on success, 0 on failure.
258 int RAND_DRBG_instantiate(RAND_DRBG
*drbg
,
259 const unsigned char *pers
, size_t perslen
)
261 unsigned char *nonce
= NULL
, *entropy
= NULL
;
262 size_t noncelen
= 0, entropylen
= 0;
264 if (perslen
> drbg
->max_perslen
) {
265 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
266 RAND_R_PERSONALISATION_STRING_TOO_LONG
);
270 if (drbg
->meth
== NULL
)
272 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
273 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
277 if (drbg
->state
!= DRBG_UNINITIALISED
) {
278 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
279 drbg
->state
== DRBG_ERROR
? RAND_R_IN_ERROR_STATE
280 : RAND_R_ALREADY_INSTANTIATED
);
284 drbg
->state
= DRBG_ERROR
;
285 if (drbg
->get_entropy
!= NULL
)
286 entropylen
= drbg
->get_entropy(drbg
, &entropy
, drbg
->strength
,
287 drbg
->min_entropylen
, drbg
->max_entropylen
);
288 if (entropylen
< drbg
->min_entropylen
289 || entropylen
> drbg
->max_entropylen
) {
290 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
294 if (drbg
->max_noncelen
> 0 && drbg
->get_nonce
!= NULL
) {
295 noncelen
= drbg
->get_nonce(drbg
, &nonce
, drbg
->strength
/ 2,
296 drbg
->min_noncelen
, drbg
->max_noncelen
);
297 if (noncelen
< drbg
->min_noncelen
|| noncelen
> drbg
->max_noncelen
) {
298 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
299 RAND_R_ERROR_RETRIEVING_NONCE
);
304 if (!drbg
->meth
->instantiate(drbg
, entropy
, entropylen
,
305 nonce
, noncelen
, pers
, perslen
)) {
306 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_INSTANTIATING_DRBG
);
310 drbg
->state
= DRBG_READY
;
311 drbg
->generate_counter
= 0;
312 drbg
->reseed_time
= time(NULL
);
313 if (drbg
->reseed_counter
> 0) {
314 if (drbg
->parent
== NULL
)
315 drbg
->reseed_counter
++;
317 drbg
->reseed_counter
= drbg
->parent
->reseed_counter
;
321 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
322 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
323 if (nonce
!= NULL
&& drbg
->cleanup_nonce
!= NULL
)
324 drbg
->cleanup_nonce(drbg
, nonce
, noncelen
);
325 if (drbg
->pool
!= NULL
) {
326 if (drbg
->state
== DRBG_READY
) {
327 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
328 RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED
);
329 drbg
->state
= DRBG_ERROR
;
331 rand_pool_free(drbg
->pool
);
334 if (drbg
->state
== DRBG_READY
)
340 * Uninstantiate |drbg|. Must be instantiated before it can be used.
342 * Requires that drbg->lock is already locked for write, if non-null.
344 * Returns 1 on success, 0 on failure.
346 int RAND_DRBG_uninstantiate(RAND_DRBG
*drbg
)
348 if (drbg
->meth
== NULL
)
350 RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE
,
351 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
355 /* Clear the entire drbg->ctr struct, then reset some important
356 * members of the drbg->ctr struct (e.g. keysize, df_ks) to their
359 drbg
->meth
->uninstantiate(drbg
);
360 return RAND_DRBG_set(drbg
, drbg
->nid
, drbg
->flags
);
364 * Reseed |drbg|, mixing in the specified data
366 * Requires that drbg->lock is already locked for write, if non-null.
368 * Returns 1 on success, 0 on failure.
370 int RAND_DRBG_reseed(RAND_DRBG
*drbg
,
371 const unsigned char *adin
, size_t adinlen
)
373 unsigned char *entropy
= NULL
;
374 size_t entropylen
= 0;
376 if (drbg
->state
== DRBG_ERROR
) {
377 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_IN_ERROR_STATE
);
380 if (drbg
->state
== DRBG_UNINITIALISED
) {
381 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_NOT_INSTANTIATED
);
387 else if (adinlen
> drbg
->max_adinlen
) {
388 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
392 drbg
->state
= DRBG_ERROR
;
393 if (drbg
->get_entropy
!= NULL
)
394 entropylen
= drbg
->get_entropy(drbg
, &entropy
, drbg
->strength
,
395 drbg
->min_entropylen
, drbg
->max_entropylen
);
396 if (entropylen
< drbg
->min_entropylen
397 || entropylen
> drbg
->max_entropylen
) {
398 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
402 if (!drbg
->meth
->reseed(drbg
, entropy
, entropylen
, adin
, adinlen
))
405 drbg
->state
= DRBG_READY
;
406 drbg
->generate_counter
= 0;
407 drbg
->reseed_time
= time(NULL
);
408 if (drbg
->reseed_counter
> 0) {
409 if (drbg
->parent
== NULL
)
410 drbg
->reseed_counter
++;
412 drbg
->reseed_counter
= drbg
->parent
->reseed_counter
;
416 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
417 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
418 if (drbg
->state
== DRBG_READY
)
424 * Restart |drbg|, using the specified entropy or additional input
426 * Tries its best to get the drbg instantiated by all means,
427 * regardless of its current state.
429 * Optionally, a |buffer| of |len| random bytes can be passed,
430 * which is assumed to contain at least |entropy| bits of entropy.
432 * If |entropy| > 0, the buffer content is used as entropy input.
434 * If |entropy| == 0, the buffer content is used as additional input
436 * Returns 1 on success, 0 on failure.
438 * This function is used internally only.
440 int rand_drbg_restart(RAND_DRBG
*drbg
,
441 const unsigned char *buffer
, size_t len
, size_t entropy
)
444 const unsigned char *adin
= NULL
;
447 if (drbg
->pool
!= NULL
) {
448 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
449 rand_pool_free(drbg
->pool
);
453 if (buffer
!= NULL
) {
455 if (drbg
->max_entropylen
< len
) {
456 RANDerr(RAND_F_RAND_DRBG_RESTART
,
457 RAND_R_ENTROPY_INPUT_TOO_LONG
);
461 if (entropy
> 8 * len
) {
462 RANDerr(RAND_F_RAND_DRBG_RESTART
, RAND_R_ENTROPY_OUT_OF_RANGE
);
466 /* will be picked up by the rand_drbg_get_entropy() callback */
467 drbg
->pool
= rand_pool_new(entropy
, len
, len
);
468 if (drbg
->pool
== NULL
)
471 rand_pool_add(drbg
->pool
, buffer
, len
, entropy
);
473 if (drbg
->max_adinlen
< len
) {
474 RANDerr(RAND_F_RAND_DRBG_RESTART
,
475 RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
483 /* repair error state */
484 if (drbg
->state
== DRBG_ERROR
)
485 RAND_DRBG_uninstantiate(drbg
);
487 /* repair uninitialized state */
488 if (drbg
->state
== DRBG_UNINITIALISED
) {
489 /* reinstantiate drbg */
490 RAND_DRBG_instantiate(drbg
,
491 (const unsigned char *) ossl_pers_string
,
492 sizeof(ossl_pers_string
) - 1);
493 /* already reseeded. prevent second reseeding below */
494 reseeded
= (drbg
->state
== DRBG_READY
);
497 /* refresh current state if entropy or additional input has been provided */
498 if (drbg
->state
== DRBG_READY
) {
501 * mix in additional input without reseeding
503 * Similar to RAND_DRBG_reseed(), but the provided additional
504 * data |adin| is mixed into the current state without pulling
505 * entropy from the trusted entropy source using get_entropy().
506 * This is not a reseeding in the strict sense of NIST SP 800-90A.
508 drbg
->meth
->reseed(drbg
, adin
, adinlen
, NULL
, 0);
509 } else if (reseeded
== 0) {
510 /* do a full reseeding if it has not been done yet above */
511 RAND_DRBG_reseed(drbg
, NULL
, 0);
515 /* check whether a given entropy pool was cleared properly during reseed */
516 if (drbg
->pool
!= NULL
) {
517 drbg
->state
= DRBG_ERROR
;
518 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
519 rand_pool_free(drbg
->pool
);
524 return drbg
->state
== DRBG_READY
;
528 * Generate |outlen| bytes into the buffer at |out|. Reseed if we need
529 * to or if |prediction_resistance| is set. Additional input can be
530 * sent in |adin| and |adinlen|.
532 * Requires that drbg->lock is already locked for write, if non-null.
534 * Returns 1 on success, 0 on failure.
537 int RAND_DRBG_generate(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
,
538 int prediction_resistance
,
539 const unsigned char *adin
, size_t adinlen
)
541 int reseed_required
= 0;
543 if (drbg
->state
!= DRBG_READY
) {
544 /* try to recover from previous errors */
545 rand_drbg_restart(drbg
, NULL
, 0, 0);
547 if (drbg
->state
== DRBG_ERROR
) {
548 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_IN_ERROR_STATE
);
551 if (drbg
->state
== DRBG_UNINITIALISED
) {
552 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_NOT_INSTANTIATED
);
557 if (outlen
> drbg
->max_request
) {
558 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG
);
561 if (adinlen
> drbg
->max_adinlen
) {
562 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
566 if (drbg
->fork_count
!= rand_fork_count
) {
567 drbg
->fork_count
= rand_fork_count
;
571 if (drbg
->reseed_interval
> 0) {
572 if (drbg
->generate_counter
>= drbg
->reseed_interval
)
575 if (drbg
->reseed_time_interval
> 0) {
576 time_t now
= time(NULL
);
577 if (now
< drbg
->reseed_time
578 || now
- drbg
->reseed_time
>= drbg
->reseed_time_interval
)
581 if (drbg
->reseed_counter
> 0 && drbg
->parent
!= NULL
) {
582 if (drbg
->reseed_counter
!= drbg
->parent
->reseed_counter
)
586 if (reseed_required
|| prediction_resistance
) {
587 if (!RAND_DRBG_reseed(drbg
, adin
, adinlen
)) {
588 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_RESEED_ERROR
);
595 if (!drbg
->meth
->generate(drbg
, out
, outlen
, adin
, adinlen
)) {
596 drbg
->state
= DRBG_ERROR
;
597 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_GENERATE_ERROR
);
601 drbg
->generate_counter
++;
607 * Generates |outlen| random bytes and stores them in |out|. It will
608 * using the given |drbg| to generate the bytes.
610 * Requires that drbg->lock is already locked for write, if non-null.
612 * Returns 1 on success 0 on failure.
614 int RAND_DRBG_bytes(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
)
616 unsigned char *additional
= NULL
;
617 size_t additional_len
;
621 additional_len
= rand_drbg_get_additional_data(&additional
, drbg
->max_adinlen
);
623 for ( ; outlen
> 0; outlen
-= chunk
, out
+= chunk
) {
625 if (chunk
> drbg
->max_request
)
626 chunk
= drbg
->max_request
;
627 ret
= RAND_DRBG_generate(drbg
, out
, chunk
, 0, additional
, additional_len
);
634 if (additional_len
!= 0)
635 OPENSSL_secure_clear_free(additional
, additional_len
);
641 * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
643 * In the following, the signature and the semantics of the
644 * get_entropy() and cleanup_entropy() callbacks are explained.
648 * size_t get_entropy(RAND_DRBG *ctx,
649 * unsigned char **pout,
651 * size_t min_len, size_t max_len);
653 * This is a request to allocate and fill a buffer of size
654 * |min_len| <= size <= |max_len| (in bytes) which contains
655 * at least |entropy| bits of randomness. The buffer's address is
656 * to be returned in |*pout| and the number of collected
657 * randomness bytes (which may be less than the allocated size
658 * of the buffer) as return value.
660 * If the callback fails to acquire at least |entropy| bits of
661 * randomness, it shall return a buffer length of 0.
665 * void cleanup_entropy(RAND_DRBG *ctx,
666 * unsigned char *out, size_t outlen);
668 * A request to clear and free the buffer allocated by get_entropy().
669 * The values |out| and |outlen| are expected to be the random buffer's
670 * address and length, as returned by the get_entropy() callback.
672 * GET_NONCE, CLEANUP_NONCE
674 * Signature and semantics of the get_nonce() and cleanup_nonce()
675 * callbacks are analogous to get_entropy() and cleanup_entropy().
676 * Currently, the nonce is used only for the known answer tests.
678 int RAND_DRBG_set_callbacks(RAND_DRBG
*drbg
,
679 RAND_DRBG_get_entropy_fn get_entropy
,
680 RAND_DRBG_cleanup_entropy_fn cleanup_entropy
,
681 RAND_DRBG_get_nonce_fn get_nonce
,
682 RAND_DRBG_cleanup_nonce_fn cleanup_nonce
)
684 if (drbg
->state
!= DRBG_UNINITIALISED
)
686 drbg
->get_entropy
= get_entropy
;
687 drbg
->cleanup_entropy
= cleanup_entropy
;
688 drbg
->get_nonce
= get_nonce
;
689 drbg
->cleanup_nonce
= cleanup_nonce
;
694 * Set the reseed interval.
696 * The drbg will reseed automatically whenever the number of generate
697 * requests exceeds the given reseed interval. If the reseed interval
698 * is 0, then this feature is disabled.
700 * Returns 1 on success, 0 on failure.
702 int RAND_DRBG_set_reseed_interval(RAND_DRBG
*drbg
, unsigned int interval
)
704 if (interval
> MAX_RESEED_INTERVAL
)
706 drbg
->reseed_interval
= interval
;
711 * Set the reseed time interval.
713 * The drbg will reseed automatically whenever the time elapsed since
714 * the last reseeding exceeds the given reseed time interval. For safety,
715 * a reseeding will also occur if the clock has been reset to a smaller
718 * Returns 1 on success, 0 on failure.
720 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG
*drbg
, time_t interval
)
722 if (interval
> MAX_RESEED_TIME_INTERVAL
)
724 drbg
->reseed_time_interval
= interval
;
729 * Set the default values for reseed (time) intervals of new DRBG instances
731 * The default values can be set independently for master DRBG instances
732 * (without a parent) and slave DRBG instances (with parent).
734 * Returns 1 on success, 0 on failure.
737 int RAND_DRBG_set_reseed_defaults(
738 unsigned int _master_reseed_interval
,
739 unsigned int _slave_reseed_interval
,
740 time_t _master_reseed_time_interval
,
741 time_t _slave_reseed_time_interval
744 if (_master_reseed_interval
> MAX_RESEED_INTERVAL
745 || _slave_reseed_interval
> MAX_RESEED_INTERVAL
)
748 if (_master_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
749 || _slave_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
)
752 master_reseed_interval
= _master_reseed_interval
;
753 slave_reseed_interval
= _slave_reseed_interval
;
755 master_reseed_time_interval
= _master_reseed_time_interval
;
756 slave_reseed_time_interval
= _slave_reseed_time_interval
;
762 * Locks the given drbg. Locking a drbg which does not have locking
763 * enabled is considered a successful no-op.
765 * Returns 1 on success, 0 on failure.
767 int rand_drbg_lock(RAND_DRBG
*drbg
)
769 if (drbg
->lock
!= NULL
)
770 return CRYPTO_THREAD_write_lock(drbg
->lock
);
776 * Unlocks the given drbg. Unlocking a drbg which does not have locking
777 * enabled is considered a successful no-op.
779 * Returns 1 on success, 0 on failure.
781 int rand_drbg_unlock(RAND_DRBG
*drbg
)
783 if (drbg
->lock
!= NULL
)
784 return CRYPTO_THREAD_unlock(drbg
->lock
);
790 * Enables locking for the given drbg
792 * Locking can only be enabled if the random generator
793 * is in the uninitialized state.
795 * Returns 1 on success, 0 on failure.
797 int rand_drbg_enable_locking(RAND_DRBG
*drbg
)
799 if (drbg
->state
!= DRBG_UNINITIALISED
) {
800 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
801 RAND_R_DRBG_ALREADY_INITIALIZED
);
805 if (drbg
->lock
== NULL
) {
806 if (drbg
->parent
!= NULL
&& drbg
->parent
->lock
== NULL
) {
807 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
808 RAND_R_PARENT_LOCKING_NOT_ENABLED
);
812 drbg
->lock
= CRYPTO_THREAD_lock_new();
813 if (drbg
->lock
== NULL
) {
814 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
815 RAND_R_FAILED_TO_CREATE_LOCK
);
824 * Get and set the EXDATA
826 int RAND_DRBG_set_ex_data(RAND_DRBG
*drbg
, int idx
, void *arg
)
828 return CRYPTO_set_ex_data(&drbg
->ex_data
, idx
, arg
);
831 void *RAND_DRBG_get_ex_data(const RAND_DRBG
*drbg
, int idx
)
833 return CRYPTO_get_ex_data(&drbg
->ex_data
, idx
);
838 * The following functions provide a RAND_METHOD that works on the
839 * global DRBG. They lock.
843 * Allocates a new global DRBG on the secure heap (if enabled) and
844 * initializes it with default settings.
846 * Returns a pointer to the new DRBG instance on success, NULL on failure.
848 static RAND_DRBG
*drbg_setup(RAND_DRBG
*parent
)
852 drbg
= RAND_DRBG_secure_new(RAND_DRBG_NID
, 0, parent
);
856 if (rand_drbg_enable_locking(drbg
) == 0)
859 /* enable seed propagation */
860 drbg
->reseed_counter
= 1;
863 * Ignore instantiation error so support just-in-time instantiation.
865 * The state of the drbg will be checked in RAND_DRBG_generate() and
866 * an automatic recovery is attempted.
868 RAND_DRBG_instantiate(drbg
,
869 (const unsigned char *) ossl_pers_string
,
870 sizeof(ossl_pers_string
) - 1);
874 RAND_DRBG_free(drbg
);
879 * Initialize the global DRBGs on first use.
880 * Returns 1 on success, 0 on failure.
882 DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init
)
885 * ensure that libcrypto is initialized, otherwise the
886 * DRBG locks are not cleaned up properly
888 if (!OPENSSL_init_crypto(0, NULL
))
891 drbg_master
= drbg_setup(NULL
);
892 drbg_public
= drbg_setup(drbg_master
);
893 drbg_private
= drbg_setup(drbg_master
);
895 if (drbg_master
== NULL
|| drbg_public
== NULL
|| drbg_private
== NULL
)
901 /* Clean up the global DRBGs before exit */
902 void rand_drbg_cleanup_int(void)
904 RAND_DRBG_free(drbg_private
);
905 RAND_DRBG_free(drbg_public
);
906 RAND_DRBG_free(drbg_master
);
908 drbg_private
= drbg_public
= drbg_master
= NULL
;
911 /* Implements the default OpenSSL RAND_bytes() method */
912 static int drbg_bytes(unsigned char *out
, int count
)
915 RAND_DRBG
*drbg
= RAND_DRBG_get0_public();
920 rand_drbg_lock(drbg
);
921 ret
= RAND_DRBG_bytes(drbg
, out
, count
);
922 rand_drbg_unlock(drbg
);
927 /* Implements the default OpenSSL RAND_add() method */
928 static int drbg_add(const void *buf
, int num
, double randomness
)
931 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
936 if (num
< 0 || randomness
< 0.0)
939 if (randomness
> (double)drbg
->max_entropylen
) {
941 * The purpose of this check is to bound |randomness| by a
942 * relatively small value in order to prevent an integer
943 * overflow when multiplying by 8 in the rand_drbg_restart()
949 rand_drbg_lock(drbg
);
950 ret
= rand_drbg_restart(drbg
, buf
,
951 (size_t)(unsigned int)num
,
952 (size_t)(8*randomness
));
953 rand_drbg_unlock(drbg
);
958 /* Implements the default OpenSSL RAND_seed() method */
959 static int drbg_seed(const void *buf
, int num
)
961 return drbg_add(buf
, num
, num
);
964 /* Implements the default OpenSSL RAND_status() method */
965 static int drbg_status(void)
968 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
973 rand_drbg_lock(drbg
);
974 ret
= drbg
->state
== DRBG_READY
? 1 : 0;
975 rand_drbg_unlock(drbg
);
980 * Get the master DRBG.
981 * Returns pointer to the DRBG on success, NULL on failure.
984 RAND_DRBG
*RAND_DRBG_get0_master(void)
986 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
993 * Get the public DRBG.
994 * Returns pointer to the DRBG on success, NULL on failure.
996 RAND_DRBG
*RAND_DRBG_get0_public(void)
998 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
1005 * Get the private DRBG.
1006 * Returns pointer to the DRBG on success, NULL on failure.
1008 RAND_DRBG
*RAND_DRBG_get0_private(void)
1010 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
1013 return drbg_private
;
1016 RAND_METHOD rand_meth
= {
1025 RAND_METHOD
*RAND_OpenSSL(void)