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 RAND_DRBG
*drbg_setup(RAND_DRBG
*parent
);
118 static RAND_DRBG
*rand_drbg_new(int secure
,
124 * Set/initialize |drbg| to be of type |nid|, with optional |flags|.
126 * Returns 1 on success, 0 on failure.
128 int RAND_DRBG_set(RAND_DRBG
*drbg
, int nid
, unsigned int flags
)
132 drbg
->state
= DRBG_UNINITIALISED
;
138 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
141 /* Uninitialized; that's okay. */
143 case NID_aes_128_ctr
:
144 case NID_aes_192_ctr
:
145 case NID_aes_256_ctr
:
146 ret
= drbg_ctr_init(drbg
);
151 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_ERROR_INITIALISING_DRBG
);
156 * Allocate memory and initialize a new DRBG. The DRBG is allocated on
157 * the secure heap if |secure| is nonzero and the secure heap is enabled.
158 * The |parent|, if not NULL, will be used as random source for reseeding.
160 * Returns a pointer to the new DRBG instance on success, NULL on failure.
162 static RAND_DRBG
*rand_drbg_new(int secure
,
167 RAND_DRBG
*drbg
= secure
?
168 OPENSSL_secure_zalloc(sizeof(*drbg
)) : OPENSSL_zalloc(sizeof(*drbg
));
171 RANDerr(RAND_F_RAND_DRBG_NEW
, ERR_R_MALLOC_FAILURE
);
175 drbg
->secure
= secure
&& CRYPTO_secure_allocated(drbg
);
176 drbg
->fork_count
= rand_fork_count
;
177 drbg
->parent
= parent
;
178 if (RAND_DRBG_set(drbg
, type
, flags
) == 0)
181 if (!RAND_DRBG_set_callbacks(drbg
, rand_drbg_get_entropy
,
182 rand_drbg_cleanup_entropy
,
190 OPENSSL_secure_free(drbg
);
197 RAND_DRBG
*RAND_DRBG_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
199 return rand_drbg_new(0, type
, flags
, parent
);
202 RAND_DRBG
*RAND_DRBG_secure_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
204 return rand_drbg_new(1, type
, flags
, parent
);
208 * Uninstantiate |drbg| and free all memory.
210 void RAND_DRBG_free(RAND_DRBG
*drbg
)
215 if (drbg
->meth
!= NULL
)
216 drbg
->meth
->uninstantiate(drbg
);
217 CRYPTO_THREAD_lock_free(drbg
->lock
);
218 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG
, drbg
, &drbg
->ex_data
);
221 OPENSSL_secure_clear_free(drbg
, sizeof(*drbg
));
223 OPENSSL_clear_free(drbg
, sizeof(*drbg
));
227 * Instantiate |drbg|, after it has been initialized. Use |pers| and
228 * |perslen| as prediction-resistance input.
230 * Requires that drbg->lock is already locked for write, if non-null.
232 * Returns 1 on success, 0 on failure.
234 int RAND_DRBG_instantiate(RAND_DRBG
*drbg
,
235 const unsigned char *pers
, size_t perslen
)
237 unsigned char *nonce
= NULL
, *entropy
= NULL
;
238 size_t noncelen
= 0, entropylen
= 0;
240 if (perslen
> drbg
->max_perslen
) {
241 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
242 RAND_R_PERSONALISATION_STRING_TOO_LONG
);
246 if (drbg
->meth
== NULL
)
248 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
249 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
253 if (drbg
->state
!= DRBG_UNINITIALISED
) {
254 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
255 drbg
->state
== DRBG_ERROR
? RAND_R_IN_ERROR_STATE
256 : RAND_R_ALREADY_INSTANTIATED
);
260 drbg
->state
= DRBG_ERROR
;
261 if (drbg
->get_entropy
!= NULL
)
262 entropylen
= drbg
->get_entropy(drbg
, &entropy
, drbg
->strength
,
263 drbg
->min_entropylen
, drbg
->max_entropylen
);
264 if (entropylen
< drbg
->min_entropylen
265 || entropylen
> drbg
->max_entropylen
) {
266 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
270 if (drbg
->max_noncelen
> 0 && drbg
->get_nonce
!= NULL
) {
271 noncelen
= drbg
->get_nonce(drbg
, &nonce
, drbg
->strength
/ 2,
272 drbg
->min_noncelen
, drbg
->max_noncelen
);
273 if (noncelen
< drbg
->min_noncelen
|| noncelen
> drbg
->max_noncelen
) {
274 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
275 RAND_R_ERROR_RETRIEVING_NONCE
);
280 if (!drbg
->meth
->instantiate(drbg
, entropy
, entropylen
,
281 nonce
, noncelen
, pers
, perslen
)) {
282 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_INSTANTIATING_DRBG
);
286 drbg
->state
= DRBG_READY
;
287 drbg
->generate_counter
= 0;
288 drbg
->reseed_time
= time(NULL
);
289 if (drbg
->reseed_counter
> 0) {
290 if (drbg
->parent
== NULL
)
291 drbg
->reseed_counter
++;
293 drbg
->reseed_counter
= drbg
->parent
->reseed_counter
;
297 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
298 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
299 if (nonce
!= NULL
&& drbg
->cleanup_nonce
!= NULL
)
300 drbg
->cleanup_nonce(drbg
, nonce
, noncelen
);
301 if (drbg
->pool
!= NULL
) {
302 if (drbg
->state
== DRBG_READY
) {
303 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
304 RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED
);
305 drbg
->state
= DRBG_ERROR
;
307 RAND_POOL_free(drbg
->pool
);
310 if (drbg
->state
== DRBG_READY
)
316 * Uninstantiate |drbg|. Must be instantiated before it can be used.
318 * Requires that drbg->lock is already locked for write, if non-null.
320 * Returns 1 on success, 0 on failure.
322 int RAND_DRBG_uninstantiate(RAND_DRBG
*drbg
)
324 if (drbg
->meth
== NULL
)
326 RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE
,
327 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
331 /* Clear the entire drbg->ctr struct, then reset some important
332 * members of the drbg->ctr struct (e.g. keysize, df_ks) to their
335 drbg
->meth
->uninstantiate(drbg
);
336 return RAND_DRBG_set(drbg
, drbg
->nid
, drbg
->flags
);
340 * Reseed |drbg|, mixing in the specified data
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_reseed(RAND_DRBG
*drbg
,
347 const unsigned char *adin
, size_t adinlen
)
349 unsigned char *entropy
= NULL
;
350 size_t entropylen
= 0;
352 if (drbg
->state
== DRBG_ERROR
) {
353 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_IN_ERROR_STATE
);
356 if (drbg
->state
== DRBG_UNINITIALISED
) {
357 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_NOT_INSTANTIATED
);
363 else if (adinlen
> drbg
->max_adinlen
) {
364 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
368 drbg
->state
= DRBG_ERROR
;
369 if (drbg
->get_entropy
!= NULL
)
370 entropylen
= drbg
->get_entropy(drbg
, &entropy
, drbg
->strength
,
371 drbg
->min_entropylen
, drbg
->max_entropylen
);
372 if (entropylen
< drbg
->min_entropylen
373 || entropylen
> drbg
->max_entropylen
) {
374 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
378 if (!drbg
->meth
->reseed(drbg
, entropy
, entropylen
, adin
, adinlen
))
381 drbg
->state
= DRBG_READY
;
382 drbg
->generate_counter
= 0;
383 drbg
->reseed_time
= time(NULL
);
384 if (drbg
->reseed_counter
> 0) {
385 if (drbg
->parent
== NULL
)
386 drbg
->reseed_counter
++;
388 drbg
->reseed_counter
= drbg
->parent
->reseed_counter
;
392 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
393 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
394 if (drbg
->state
== DRBG_READY
)
400 * Restart |drbg|, using the specified entropy or additional input
402 * Tries its best to get the drbg instantiated by all means,
403 * regardless of its current state.
405 * Optionally, a |buffer| of |len| random bytes can be passed,
406 * which is assumed to contain at least |entropy| bits of entropy.
408 * If |entropy| > 0, the buffer content is used as entropy input.
410 * If |entropy| == 0, the buffer content is used as additional input
412 * Returns 1 on success, 0 on failure.
414 * This function is used internally only.
416 int rand_drbg_restart(RAND_DRBG
*drbg
,
417 const unsigned char *buffer
, size_t len
, size_t entropy
)
420 const unsigned char *adin
= NULL
;
423 if (drbg
->pool
!= NULL
) {
424 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
425 RAND_POOL_free(drbg
->pool
);
429 if (buffer
!= NULL
) {
431 if (drbg
->max_entropylen
< len
) {
432 RANDerr(RAND_F_RAND_DRBG_RESTART
,
433 RAND_R_ENTROPY_INPUT_TOO_LONG
);
437 if (entropy
> 8 * len
) {
438 RANDerr(RAND_F_RAND_DRBG_RESTART
, RAND_R_ENTROPY_OUT_OF_RANGE
);
442 /* will be picked up by the rand_drbg_get_entropy() callback */
443 drbg
->pool
= RAND_POOL_new(entropy
, len
, len
);
444 if (drbg
->pool
== NULL
)
447 RAND_POOL_add(drbg
->pool
, buffer
, len
, entropy
);
449 if (drbg
->max_adinlen
< len
) {
450 RANDerr(RAND_F_RAND_DRBG_RESTART
,
451 RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
459 /* repair error state */
460 if (drbg
->state
== DRBG_ERROR
)
461 RAND_DRBG_uninstantiate(drbg
);
463 /* repair uninitialized state */
464 if (drbg
->state
== DRBG_UNINITIALISED
) {
465 /* reinstantiate drbg */
466 RAND_DRBG_instantiate(drbg
,
467 (const unsigned char *) ossl_pers_string
,
468 sizeof(ossl_pers_string
) - 1);
469 /* already reseeded. prevent second reseeding below */
470 reseeded
= (drbg
->state
== DRBG_READY
);
473 /* refresh current state if entropy or additional input has been provided */
474 if (drbg
->state
== DRBG_READY
) {
477 * mix in additional input without reseeding
479 * Similar to RAND_DRBG_reseed(), but the provided additional
480 * data |adin| is mixed into the current state without pulling
481 * entropy from the trusted entropy source using get_entropy().
482 * This is not a reseeding in the strict sense of NIST SP 800-90A.
484 drbg
->meth
->reseed(drbg
, adin
, adinlen
, NULL
, 0);
485 } else if (reseeded
== 0) {
486 /* do a full reseeding if it has not been done yet above */
487 RAND_DRBG_reseed(drbg
, NULL
, 0);
491 /* check whether a given entropy pool was cleared properly during reseed */
492 if (drbg
->pool
!= NULL
) {
493 drbg
->state
= DRBG_ERROR
;
494 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
495 RAND_POOL_free(drbg
->pool
);
500 return drbg
->state
== DRBG_READY
;
504 * Generate |outlen| bytes into the buffer at |out|. Reseed if we need
505 * to or if |prediction_resistance| is set. Additional input can be
506 * sent in |adin| and |adinlen|.
508 * Requires that drbg->lock is already locked for write, if non-null.
510 * Returns 1 on success, 0 on failure.
513 int RAND_DRBG_generate(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
,
514 int prediction_resistance
,
515 const unsigned char *adin
, size_t adinlen
)
517 int reseed_required
= 0;
519 if (drbg
->state
!= DRBG_READY
) {
520 /* try to recover from previous errors */
521 rand_drbg_restart(drbg
, NULL
, 0, 0);
523 if (drbg
->state
== DRBG_ERROR
) {
524 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_IN_ERROR_STATE
);
527 if (drbg
->state
== DRBG_UNINITIALISED
) {
528 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_NOT_INSTANTIATED
);
533 if (outlen
> drbg
->max_request
) {
534 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG
);
537 if (adinlen
> drbg
->max_adinlen
) {
538 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
542 if (drbg
->fork_count
!= rand_fork_count
) {
543 drbg
->fork_count
= rand_fork_count
;
547 if (drbg
->reseed_interval
> 0) {
548 if (drbg
->generate_counter
>= drbg
->reseed_interval
)
551 if (drbg
->reseed_time_interval
> 0) {
552 time_t now
= time(NULL
);
553 if (now
< drbg
->reseed_time
554 || now
- drbg
->reseed_time
>= drbg
->reseed_time_interval
)
557 if (drbg
->reseed_counter
> 0 && drbg
->parent
!= NULL
) {
558 if (drbg
->reseed_counter
!= drbg
->parent
->reseed_counter
)
562 if (reseed_required
|| prediction_resistance
) {
563 if (!RAND_DRBG_reseed(drbg
, adin
, adinlen
)) {
564 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_RESEED_ERROR
);
571 if (!drbg
->meth
->generate(drbg
, out
, outlen
, adin
, adinlen
)) {
572 drbg
->state
= DRBG_ERROR
;
573 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_GENERATE_ERROR
);
577 drbg
->generate_counter
++;
583 * Generates |outlen| random bytes and stores them in |out|. It will
584 * using the given |drbg| to generate the bytes.
586 * Requires that drbg->lock is already locked for write, if non-null.
588 * Returns 1 on success 0 on failure.
590 int RAND_DRBG_bytes(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
)
592 unsigned char *additional
= NULL
;
593 size_t additional_len
;
597 additional_len
= rand_drbg_get_additional_data(&additional
, drbg
->max_adinlen
);
599 for ( ; outlen
> 0; outlen
-= chunk
, out
+= chunk
) {
601 if (chunk
> drbg
->max_request
)
602 chunk
= drbg
->max_request
;
603 ret
= RAND_DRBG_generate(drbg
, out
, chunk
, 0, additional
, additional_len
);
610 if (additional_len
!= 0)
611 OPENSSL_secure_clear_free(additional
, additional_len
);
617 * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
619 * In the following, the signature and the semantics of the
620 * get_entropy() and cleanup_entropy() callbacks are explained.
624 * size_t get_entropy(RAND_DRBG *ctx,
625 * unsigned char **pout,
627 * size_t min_len, size_t max_len);
629 * This is a request to allocate and fill a buffer of size
630 * |min_len| <= size <= |max_len| (in bytes) which contains
631 * at least |entropy| bits of randomness. The buffer's address is
632 * to be returned in |*pout| and the number of collected
633 * randomness bytes (which may be less than the allocated size
634 * of the buffer) as return value.
636 * If the callback fails to acquire at least |entropy| bits of
637 * randomness, it shall return a buffer length of 0.
641 * void cleanup_entropy(RAND_DRBG *ctx,
642 * unsigned char *out, size_t outlen);
644 * A request to clear and free the buffer allocated by get_entropy().
645 * The values |out| and |outlen| are expected to be the random buffer's
646 * address and length, as returned by the get_entropy() callback.
648 * GET_NONCE, CLEANUP_NONCE
650 * Signature and semantics of the get_nonce() and cleanup_nonce()
651 * callbacks are analogous to get_entropy() and cleanup_entropy().
652 * Currently, the nonce is used only for the known answer tests.
654 int RAND_DRBG_set_callbacks(RAND_DRBG
*drbg
,
655 RAND_DRBG_get_entropy_fn get_entropy
,
656 RAND_DRBG_cleanup_entropy_fn cleanup_entropy
,
657 RAND_DRBG_get_nonce_fn get_nonce
,
658 RAND_DRBG_cleanup_nonce_fn cleanup_nonce
)
660 if (drbg
->state
!= DRBG_UNINITIALISED
)
662 drbg
->get_entropy
= get_entropy
;
663 drbg
->cleanup_entropy
= cleanup_entropy
;
664 drbg
->get_nonce
= get_nonce
;
665 drbg
->cleanup_nonce
= cleanup_nonce
;
670 * Set the reseed interval.
672 * The drbg will reseed automatically whenever the number of generate
673 * requests exceeds the given reseed interval. If the reseed interval
674 * is 0, then this feature is disabled.
676 * Returns 1 on success, 0 on failure.
678 int RAND_DRBG_set_reseed_interval(RAND_DRBG
*drbg
, unsigned int interval
)
680 if (interval
> MAX_RESEED_INTERVAL
)
682 drbg
->reseed_interval
= interval
;
687 * Set the reseed time interval.
689 * The drbg will reseed automatically whenever the time elapsed since
690 * the last reseeding exceeds the given reseed time interval. For safety,
691 * a reseeding will also occur if the clock has been reset to a smaller
694 * Returns 1 on success, 0 on failure.
696 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG
*drbg
, time_t interval
)
698 if (interval
> MAX_RESEED_TIME_INTERVAL
)
700 drbg
->reseed_time_interval
= interval
;
706 * Locks the given drbg. Locking a drbg which does not have locking
707 * enabled is considered a successful no-op.
709 * Returns 1 on success, 0 on failure.
711 int rand_drbg_lock(RAND_DRBG
*drbg
)
713 if (drbg
->lock
!= NULL
)
714 return CRYPTO_THREAD_write_lock(drbg
->lock
);
720 * Unlocks the given drbg. Unlocking a drbg which does not have locking
721 * enabled is considered a successful no-op.
723 * Returns 1 on success, 0 on failure.
725 int rand_drbg_unlock(RAND_DRBG
*drbg
)
727 if (drbg
->lock
!= NULL
)
728 return CRYPTO_THREAD_unlock(drbg
->lock
);
734 * Enables locking for the given drbg
736 * Locking can only be enabled if the random generator
737 * is in the uninitialized state.
739 * Returns 1 on success, 0 on failure.
741 int rand_drbg_enable_locking(RAND_DRBG
*drbg
)
743 if (drbg
->state
!= DRBG_UNINITIALISED
) {
744 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
745 RAND_R_DRBG_ALREADY_INITIALIZED
);
749 if (drbg
->lock
== NULL
) {
750 if (drbg
->parent
!= NULL
&& drbg
->parent
->lock
== NULL
) {
751 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
752 RAND_R_PARENT_LOCKING_NOT_ENABLED
);
756 drbg
->lock
= CRYPTO_THREAD_lock_new();
757 if (drbg
->lock
== NULL
) {
758 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
759 RAND_R_FAILED_TO_CREATE_LOCK
);
768 * Get and set the EXDATA
770 int RAND_DRBG_set_ex_data(RAND_DRBG
*drbg
, int idx
, void *arg
)
772 return CRYPTO_set_ex_data(&drbg
->ex_data
, idx
, arg
);
775 void *RAND_DRBG_get_ex_data(const RAND_DRBG
*drbg
, int idx
)
777 return CRYPTO_get_ex_data(&drbg
->ex_data
, idx
);
782 * The following functions provide a RAND_METHOD that works on the
783 * global DRBG. They lock.
787 * Allocates a new global DRBG on the secure heap (if enabled) and
788 * initializes it with default settings.
790 * Returns a pointer to the new DRBG instance on success, NULL on failure.
792 static RAND_DRBG
*drbg_setup(RAND_DRBG
*parent
)
796 drbg
= RAND_DRBG_secure_new(RAND_DRBG_NID
, 0, parent
);
800 if (rand_drbg_enable_locking(drbg
) == 0)
803 if (parent
== NULL
) {
804 drbg
->reseed_interval
= MASTER_RESEED_INTERVAL
;
805 drbg
->reseed_time_interval
= MASTER_RESEED_TIME_INTERVAL
;
807 drbg
->reseed_interval
= SLAVE_RESEED_INTERVAL
;
808 drbg
->reseed_time_interval
= SLAVE_RESEED_TIME_INTERVAL
;
811 /* enable seed propagation */
812 drbg
->reseed_counter
= 1;
815 * Ignore instantiation error so support just-in-time instantiation.
817 * The state of the drbg will be checked in RAND_DRBG_generate() and
818 * an automatic recovery is attempted.
820 RAND_DRBG_instantiate(drbg
,
821 (const unsigned char *) ossl_pers_string
,
822 sizeof(ossl_pers_string
) - 1);
826 RAND_DRBG_free(drbg
);
831 * Initialize the global DRBGs on first use.
832 * Returns 1 on success, 0 on failure.
834 DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init
)
837 * ensure that libcrypto is initialized, otherwise the
838 * DRBG locks are not cleaned up properly
840 if (!OPENSSL_init_crypto(0, NULL
))
843 drbg_master
= drbg_setup(NULL
);
844 drbg_public
= drbg_setup(drbg_master
);
845 drbg_private
= drbg_setup(drbg_master
);
847 if (drbg_master
== NULL
|| drbg_public
== NULL
|| drbg_private
== NULL
)
853 /* Clean up the global DRBGs before exit */
854 void rand_drbg_cleanup_int(void)
856 RAND_DRBG_free(drbg_private
);
857 RAND_DRBG_free(drbg_public
);
858 RAND_DRBG_free(drbg_master
);
860 drbg_private
= drbg_public
= drbg_master
= NULL
;
863 /* Implements the default OpenSSL RAND_bytes() method */
864 static int drbg_bytes(unsigned char *out
, int count
)
867 RAND_DRBG
*drbg
= RAND_DRBG_get0_public();
872 rand_drbg_lock(drbg
);
873 ret
= RAND_DRBG_bytes(drbg
, out
, count
);
874 rand_drbg_unlock(drbg
);
879 /* Implements the default OpenSSL RAND_add() method */
880 static int drbg_add(const void *buf
, int num
, double randomness
)
883 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
888 if (num
< 0 || randomness
< 0.0)
891 if (randomness
> (double)drbg
->max_entropylen
) {
893 * The purpose of this check is to bound |randomness| by a
894 * relatively small value in order to prevent an integer
895 * overflow when multiplying by 8 in the rand_drbg_restart()
901 rand_drbg_lock(drbg
);
902 ret
= rand_drbg_restart(drbg
, buf
,
903 (size_t)(unsigned int)num
,
904 (size_t)(8*randomness
));
905 rand_drbg_unlock(drbg
);
910 /* Implements the default OpenSSL RAND_seed() method */
911 static int drbg_seed(const void *buf
, int num
)
913 return drbg_add(buf
, num
, num
);
916 /* Implements the default OpenSSL RAND_status() method */
917 static int drbg_status(void)
920 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
925 rand_drbg_lock(drbg
);
926 ret
= drbg
->state
== DRBG_READY
? 1 : 0;
927 rand_drbg_unlock(drbg
);
932 * Get the master DRBG.
933 * Returns pointer to the DRBG on success, NULL on failure.
936 RAND_DRBG
*RAND_DRBG_get0_master(void)
938 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
945 * Get the public DRBG.
946 * Returns pointer to the DRBG on success, NULL on failure.
948 RAND_DRBG
*RAND_DRBG_get0_public(void)
950 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
957 * Get the private DRBG.
958 * Returns pointer to the DRBG on success, NULL on failure.
960 RAND_DRBG
*RAND_DRBG_get0_private(void)
962 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
968 RAND_METHOD rand_meth
= {
977 RAND_METHOD
*RAND_OpenSSL(void)