xref: /third_party/openssl/crypto/rand/rand_lib.c (revision e1051a39)
1/*
2 * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.
3 *
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
8 */
9
10/* We need to use some engine deprecated APIs */
11#define OPENSSL_SUPPRESS_DEPRECATED
12
13#include <openssl/err.h>
14#include <openssl/opensslconf.h>
15#include <openssl/core_names.h>
16#include "internal/cryptlib.h"
17#include "internal/thread_once.h"
18#include "crypto/rand.h"
19#include "crypto/cryptlib.h"
20#include "rand_local.h"
21
22#ifndef FIPS_MODULE
23# include <stdio.h>
24# include <time.h>
25# include <limits.h>
26# include <openssl/conf.h>
27# include <openssl/trace.h>
28# include <openssl/engine.h>
29# include "crypto/rand_pool.h"
30# include "prov/seeding.h"
31# include "e_os.h"
32
33# ifndef OPENSSL_NO_ENGINE
34/* non-NULL if default_RAND_meth is ENGINE-provided */
35static ENGINE *funct_ref;
36static CRYPTO_RWLOCK *rand_engine_lock;
37# endif
38# ifndef OPENSSL_NO_DEPRECATED_3_0
39static CRYPTO_RWLOCK *rand_meth_lock;
40static const RAND_METHOD *default_RAND_meth;
41# endif
42static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT;
43
44static int rand_inited = 0;
45
46DEFINE_RUN_ONCE_STATIC(do_rand_init)
47{
48# ifndef OPENSSL_NO_ENGINE
49    rand_engine_lock = CRYPTO_THREAD_lock_new();
50    if (rand_engine_lock == NULL)
51        return 0;
52# endif
53
54# ifndef OPENSSL_NO_DEPRECATED_3_0
55    rand_meth_lock = CRYPTO_THREAD_lock_new();
56    if (rand_meth_lock == NULL)
57        goto err;
58# endif
59
60    if (!ossl_rand_pool_init())
61        goto err;
62
63    rand_inited = 1;
64    return 1;
65
66 err:
67# ifndef OPENSSL_NO_DEPRECATED_3_0
68    CRYPTO_THREAD_lock_free(rand_meth_lock);
69    rand_meth_lock = NULL;
70# endif
71# ifndef OPENSSL_NO_ENGINE
72    CRYPTO_THREAD_lock_free(rand_engine_lock);
73    rand_engine_lock = NULL;
74# endif
75    return 0;
76}
77
78void ossl_rand_cleanup_int(void)
79{
80# ifndef OPENSSL_NO_DEPRECATED_3_0
81    const RAND_METHOD *meth = default_RAND_meth;
82
83    if (!rand_inited)
84        return;
85
86    if (meth != NULL && meth->cleanup != NULL)
87        meth->cleanup();
88    RAND_set_rand_method(NULL);
89# endif
90    ossl_rand_pool_cleanup();
91# ifndef OPENSSL_NO_ENGINE
92    CRYPTO_THREAD_lock_free(rand_engine_lock);
93    rand_engine_lock = NULL;
94# endif
95# ifndef OPENSSL_NO_DEPRECATED_3_0
96    CRYPTO_THREAD_lock_free(rand_meth_lock);
97    rand_meth_lock = NULL;
98# endif
99    ossl_release_default_drbg_ctx();
100    rand_inited = 0;
101}
102
103/*
104 * RAND_close_seed_files() ensures that any seed file descriptors are
105 * closed after use.  This only applies to libcrypto/default provider,
106 * it does not apply to other providers.
107 */
108void RAND_keep_random_devices_open(int keep)
109{
110    if (RUN_ONCE(&rand_init, do_rand_init))
111        ossl_rand_pool_keep_random_devices_open(keep);
112}
113
114/*
115 * RAND_poll() reseeds the default RNG using random input
116 *
117 * The random input is obtained from polling various entropy
118 * sources which depend on the operating system and are
119 * configurable via the --with-rand-seed configure option.
120 */
121int RAND_poll(void)
122{
123# ifndef OPENSSL_NO_DEPRECATED_3_0
124    const RAND_METHOD *meth = RAND_get_rand_method();
125    int ret = meth == RAND_OpenSSL();
126
127    if (meth == NULL)
128        return 0;
129
130    if (!ret) {
131        /* fill random pool and seed the current legacy RNG */
132        RAND_POOL *pool = ossl_rand_pool_new(RAND_DRBG_STRENGTH, 1,
133                                             (RAND_DRBG_STRENGTH + 7) / 8,
134                                             RAND_POOL_MAX_LENGTH);
135
136        if (pool == NULL)
137            return 0;
138
139        if (ossl_pool_acquire_entropy(pool) == 0)
140            goto err;
141
142        if (meth->add == NULL
143            || meth->add(ossl_rand_pool_buffer(pool),
144                         ossl_rand_pool_length(pool),
145                         (ossl_rand_pool_entropy(pool) / 8.0)) == 0)
146            goto err;
147
148        ret = 1;
149     err:
150        ossl_rand_pool_free(pool);
151    }
152    return ret;
153# else
154    static const char salt[] = "polling";
155
156    RAND_seed(salt, sizeof(salt));
157    return 1;
158# endif
159}
160
161# ifndef OPENSSL_NO_DEPRECATED_3_0
162static int rand_set_rand_method_internal(const RAND_METHOD *meth,
163                                         ossl_unused ENGINE *e)
164{
165    if (!RUN_ONCE(&rand_init, do_rand_init))
166        return 0;
167
168    if (!CRYPTO_THREAD_write_lock(rand_meth_lock))
169        return 0;
170#  ifndef OPENSSL_NO_ENGINE
171    ENGINE_finish(funct_ref);
172    funct_ref = e;
173#  endif
174    default_RAND_meth = meth;
175    CRYPTO_THREAD_unlock(rand_meth_lock);
176    return 1;
177}
178
179int RAND_set_rand_method(const RAND_METHOD *meth)
180{
181    return rand_set_rand_method_internal(meth, NULL);
182}
183
184const RAND_METHOD *RAND_get_rand_method(void)
185{
186    const RAND_METHOD *tmp_meth = NULL;
187
188    if (!RUN_ONCE(&rand_init, do_rand_init))
189        return NULL;
190
191    if (!CRYPTO_THREAD_write_lock(rand_meth_lock))
192        return NULL;
193    if (default_RAND_meth == NULL) {
194#  ifndef OPENSSL_NO_ENGINE
195        ENGINE *e;
196
197        /* If we have an engine that can do RAND, use it. */
198        if ((e = ENGINE_get_default_RAND()) != NULL
199                && (tmp_meth = ENGINE_get_RAND(e)) != NULL) {
200            funct_ref = e;
201            default_RAND_meth = tmp_meth;
202        } else {
203            ENGINE_finish(e);
204            default_RAND_meth = &ossl_rand_meth;
205        }
206#  else
207        default_RAND_meth = &ossl_rand_meth;
208#  endif
209    }
210    tmp_meth = default_RAND_meth;
211    CRYPTO_THREAD_unlock(rand_meth_lock);
212    return tmp_meth;
213}
214
215#  if !defined(OPENSSL_NO_ENGINE)
216int RAND_set_rand_engine(ENGINE *engine)
217{
218    const RAND_METHOD *tmp_meth = NULL;
219
220    if (!RUN_ONCE(&rand_init, do_rand_init))
221        return 0;
222
223    if (engine != NULL) {
224        if (!ENGINE_init(engine))
225            return 0;
226        tmp_meth = ENGINE_get_RAND(engine);
227        if (tmp_meth == NULL) {
228            ENGINE_finish(engine);
229            return 0;
230        }
231    }
232    if (!CRYPTO_THREAD_write_lock(rand_engine_lock)) {
233        ENGINE_finish(engine);
234        return 0;
235    }
236
237    /* This function releases any prior ENGINE so call it first */
238    rand_set_rand_method_internal(tmp_meth, engine);
239    CRYPTO_THREAD_unlock(rand_engine_lock);
240    return 1;
241}
242#  endif
243# endif /* OPENSSL_NO_DEPRECATED_3_0 */
244
245void RAND_seed(const void *buf, int num)
246{
247    EVP_RAND_CTX *drbg;
248# ifndef OPENSSL_NO_DEPRECATED_3_0
249    const RAND_METHOD *meth = RAND_get_rand_method();
250
251    if (meth != NULL && meth->seed != NULL) {
252        meth->seed(buf, num);
253        return;
254    }
255# endif
256
257    drbg = RAND_get0_primary(NULL);
258    if (drbg != NULL && num > 0)
259        EVP_RAND_reseed(drbg, 0, NULL, 0, buf, num);
260}
261
262void RAND_add(const void *buf, int num, double randomness)
263{
264    EVP_RAND_CTX *drbg;
265# ifndef OPENSSL_NO_DEPRECATED_3_0
266    const RAND_METHOD *meth = RAND_get_rand_method();
267
268    if (meth != NULL && meth->add != NULL) {
269        meth->add(buf, num, randomness);
270        return;
271    }
272# endif
273    drbg = RAND_get0_primary(NULL);
274    if (drbg != NULL && num > 0)
275# ifdef OPENSSL_RAND_SEED_NONE
276        /* Without an entropy source, we have to rely on the user */
277        EVP_RAND_reseed(drbg, 0, buf, num, NULL, 0);
278# else
279        /* With an entropy source, we downgrade this to additional input */
280        EVP_RAND_reseed(drbg, 0, NULL, 0, buf, num);
281# endif
282}
283
284# if !defined(OPENSSL_NO_DEPRECATED_1_1_0)
285int RAND_pseudo_bytes(unsigned char *buf, int num)
286{
287    const RAND_METHOD *meth = RAND_get_rand_method();
288
289    if (meth != NULL && meth->pseudorand != NULL)
290        return meth->pseudorand(buf, num);
291    ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED);
292    return -1;
293}
294# endif
295
296int RAND_status(void)
297{
298    EVP_RAND_CTX *rand;
299# ifndef OPENSSL_NO_DEPRECATED_3_0
300    const RAND_METHOD *meth = RAND_get_rand_method();
301
302    if (meth != NULL && meth != RAND_OpenSSL())
303        return meth->status != NULL ? meth->status() : 0;
304# endif
305
306    if ((rand = RAND_get0_primary(NULL)) == NULL)
307        return 0;
308    return EVP_RAND_get_state(rand) == EVP_RAND_STATE_READY;
309}
310# else  /* !FIPS_MODULE */
311
312# ifndef OPENSSL_NO_DEPRECATED_3_0
313const RAND_METHOD *RAND_get_rand_method(void)
314{
315    return NULL;
316}
317# endif
318#endif /* !FIPS_MODULE */
319
320/*
321 * This function is not part of RAND_METHOD, so if we're not using
322 * the default method, then just call RAND_bytes().  Otherwise make
323 * sure we're instantiated and use the private DRBG.
324 */
325int RAND_priv_bytes_ex(OSSL_LIB_CTX *ctx, unsigned char *buf, size_t num,
326                       unsigned int strength)
327{
328    EVP_RAND_CTX *rand;
329#if !defined(OPENSSL_NO_DEPRECATED_3_0) && !defined(FIPS_MODULE)
330    const RAND_METHOD *meth = RAND_get_rand_method();
331
332    if (meth != NULL && meth != RAND_OpenSSL()) {
333        if (meth->bytes != NULL)
334            return meth->bytes(buf, num);
335        ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED);
336        return -1;
337    }
338#endif
339
340    rand = RAND_get0_private(ctx);
341    if (rand != NULL)
342        return EVP_RAND_generate(rand, buf, num, strength, 0, NULL, 0);
343
344    return 0;
345}
346
347int RAND_priv_bytes(unsigned char *buf, int num)
348{
349    if (num < 0)
350        return 0;
351    return RAND_priv_bytes_ex(NULL, buf, (size_t)num, 0);
352}
353
354int RAND_bytes_ex(OSSL_LIB_CTX *ctx, unsigned char *buf, size_t num,
355                  unsigned int strength)
356{
357    EVP_RAND_CTX *rand;
358#if !defined(OPENSSL_NO_DEPRECATED_3_0) && !defined(FIPS_MODULE)
359    const RAND_METHOD *meth = RAND_get_rand_method();
360
361    if (meth != NULL && meth != RAND_OpenSSL()) {
362        if (meth->bytes != NULL)
363            return meth->bytes(buf, num);
364        ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED);
365        return -1;
366    }
367#endif
368
369    rand = RAND_get0_public(ctx);
370    if (rand != NULL)
371        return EVP_RAND_generate(rand, buf, num, strength, 0, NULL, 0);
372
373    return 0;
374}
375
376int RAND_bytes(unsigned char *buf, int num)
377{
378    if (num < 0)
379        return 0;
380    return RAND_bytes_ex(NULL, buf, (size_t)num, 0);
381}
382
383typedef struct rand_global_st {
384    /*
385     * The three shared DRBG instances
386     *
387     * There are three shared DRBG instances: <primary>, <public>, and
388     * <private>.  The <public> and <private> DRBGs are secondary ones.
389     * These are used for non-secret (e.g. nonces) and secret
390     * (e.g. private keys) data respectively.
391     */
392    CRYPTO_RWLOCK *lock;
393
394    EVP_RAND_CTX *seed;
395
396    /*
397     * The <primary> DRBG
398     *
399     * Not used directly by the application, only for reseeding the two other
400     * DRBGs. It reseeds itself by pulling either randomness from os entropy
401     * sources or by consuming randomness which was added by RAND_add().
402     *
403     * The <primary> DRBG is a global instance which is accessed concurrently by
404     * all threads. The necessary locking is managed automatically by its child
405     * DRBG instances during reseeding.
406     */
407    EVP_RAND_CTX *primary;
408
409    /*
410     * The <public> DRBG
411     *
412     * Used by default for generating random bytes using RAND_bytes().
413     *
414     * The <public> secondary DRBG is thread-local, i.e., there is one instance
415     * per thread.
416     */
417    CRYPTO_THREAD_LOCAL public;
418
419    /*
420     * The <private> DRBG
421     *
422     * Used by default for generating private keys using RAND_priv_bytes()
423     *
424     * The <private> secondary DRBG is thread-local, i.e., there is one
425     * instance per thread.
426     */
427    CRYPTO_THREAD_LOCAL private;
428
429    /* Which RNG is being used by default and it's configuration settings */
430    char *rng_name;
431    char *rng_cipher;
432    char *rng_digest;
433    char *rng_propq;
434
435    /* Allow the randomness source to be changed */
436    char *seed_name;
437    char *seed_propq;
438} RAND_GLOBAL;
439
440/*
441 * Initialize the OSSL_LIB_CTX global DRBGs on first use.
442 * Returns the allocated global data on success or NULL on failure.
443 */
444static void *rand_ossl_ctx_new(OSSL_LIB_CTX *libctx)
445{
446    RAND_GLOBAL *dgbl = OPENSSL_zalloc(sizeof(*dgbl));
447
448    if (dgbl == NULL)
449        return NULL;
450
451#ifndef FIPS_MODULE
452    /*
453     * We need to ensure that base libcrypto thread handling has been
454     * initialised.
455     */
456     OPENSSL_init_crypto(OPENSSL_INIT_BASE_ONLY, NULL);
457#endif
458
459    dgbl->lock = CRYPTO_THREAD_lock_new();
460    if (dgbl->lock == NULL)
461        goto err1;
462
463    if (!CRYPTO_THREAD_init_local(&dgbl->private, NULL))
464        goto err1;
465
466    if (!CRYPTO_THREAD_init_local(&dgbl->public, NULL))
467        goto err2;
468
469    return dgbl;
470
471 err2:
472    CRYPTO_THREAD_cleanup_local(&dgbl->private);
473 err1:
474    CRYPTO_THREAD_lock_free(dgbl->lock);
475    OPENSSL_free(dgbl);
476    return NULL;
477}
478
479void ossl_rand_ctx_free(void *vdgbl)
480{
481    RAND_GLOBAL *dgbl = vdgbl;
482
483    if (dgbl == NULL)
484        return;
485
486    CRYPTO_THREAD_lock_free(dgbl->lock);
487    CRYPTO_THREAD_cleanup_local(&dgbl->private);
488    CRYPTO_THREAD_cleanup_local(&dgbl->public);
489    EVP_RAND_CTX_free(dgbl->primary);
490    EVP_RAND_CTX_free(dgbl->seed);
491    OPENSSL_free(dgbl->rng_name);
492    OPENSSL_free(dgbl->rng_cipher);
493    OPENSSL_free(dgbl->rng_digest);
494    OPENSSL_free(dgbl->rng_propq);
495    OPENSSL_free(dgbl->seed_name);
496    OPENSSL_free(dgbl->seed_propq);
497
498    OPENSSL_free(dgbl);
499}
500
501static const OSSL_LIB_CTX_METHOD rand_drbg_ossl_ctx_method = {
502    OSSL_LIB_CTX_METHOD_PRIORITY_2,
503    rand_ossl_ctx_new,
504    ossl_rand_ctx_free,
505};
506
507static RAND_GLOBAL *rand_get_global(OSSL_LIB_CTX *libctx)
508{
509    return ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_DRBG_INDEX,
510                                 &rand_drbg_ossl_ctx_method);
511}
512
513static void rand_delete_thread_state(void *arg)
514{
515    OSSL_LIB_CTX *ctx = arg;
516    RAND_GLOBAL *dgbl = rand_get_global(ctx);
517    EVP_RAND_CTX *rand;
518
519    if (dgbl == NULL)
520        return;
521
522    rand = CRYPTO_THREAD_get_local(&dgbl->public);
523    CRYPTO_THREAD_set_local(&dgbl->public, NULL);
524    EVP_RAND_CTX_free(rand);
525
526    rand = CRYPTO_THREAD_get_local(&dgbl->private);
527    CRYPTO_THREAD_set_local(&dgbl->private, NULL);
528    EVP_RAND_CTX_free(rand);
529}
530
531#ifndef FIPS_MODULE
532static EVP_RAND_CTX *rand_new_seed(OSSL_LIB_CTX *libctx)
533{
534    EVP_RAND *rand;
535    RAND_GLOBAL *dgbl = rand_get_global(libctx);
536    EVP_RAND_CTX *ctx;
537    char *name;
538
539    if (dgbl == NULL)
540        return NULL;
541    name = dgbl->seed_name != NULL ? dgbl->seed_name : "SEED-SRC";
542    rand = EVP_RAND_fetch(libctx, name, dgbl->seed_propq);
543    if (rand == NULL) {
544        ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_FETCH_DRBG);
545        return NULL;
546    }
547    ctx = EVP_RAND_CTX_new(rand, NULL);
548    EVP_RAND_free(rand);
549    if (ctx == NULL) {
550        ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_CREATE_DRBG);
551        return NULL;
552    }
553    if (!EVP_RAND_instantiate(ctx, 0, 0, NULL, 0, NULL)) {
554        ERR_raise(ERR_LIB_RAND, RAND_R_ERROR_INSTANTIATING_DRBG);
555        EVP_RAND_CTX_free(ctx);
556        return NULL;
557    }
558    return ctx;
559}
560#endif
561
562static EVP_RAND_CTX *rand_new_drbg(OSSL_LIB_CTX *libctx, EVP_RAND_CTX *parent,
563                                   unsigned int reseed_interval,
564                                   time_t reseed_time_interval)
565{
566    EVP_RAND *rand;
567    RAND_GLOBAL *dgbl = rand_get_global(libctx);
568    EVP_RAND_CTX *ctx;
569    OSSL_PARAM params[7], *p = params;
570    char *name, *cipher;
571
572    if (dgbl == NULL)
573        return NULL;
574    name = dgbl->rng_name != NULL ? dgbl->rng_name : "CTR-DRBG";
575    rand = EVP_RAND_fetch(libctx, name, dgbl->rng_propq);
576    if (rand == NULL) {
577        ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_FETCH_DRBG);
578        return NULL;
579    }
580    ctx = EVP_RAND_CTX_new(rand, parent);
581    EVP_RAND_free(rand);
582    if (ctx == NULL) {
583        ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_CREATE_DRBG);
584        return NULL;
585    }
586
587    /*
588     * Rather than trying to decode the DRBG settings, just pass them through
589     * and rely on the other end to ignore those it doesn't care about.
590     */
591    cipher = dgbl->rng_cipher != NULL ? dgbl->rng_cipher : "AES-256-CTR";
592    *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_CIPHER,
593                                            cipher, 0);
594    if (dgbl->rng_digest != NULL)
595        *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_DIGEST,
596                                                dgbl->rng_digest, 0);
597    if (dgbl->rng_propq != NULL)
598        *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_PROPERTIES,
599                                                dgbl->rng_propq, 0);
600    *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_MAC, "HMAC", 0);
601    *p++ = OSSL_PARAM_construct_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS,
602                                     &reseed_interval);
603    *p++ = OSSL_PARAM_construct_time_t(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL,
604                                       &reseed_time_interval);
605    *p = OSSL_PARAM_construct_end();
606    if (!EVP_RAND_instantiate(ctx, 0, 0, NULL, 0, params)) {
607        ERR_raise(ERR_LIB_RAND, RAND_R_ERROR_INSTANTIATING_DRBG);
608        EVP_RAND_CTX_free(ctx);
609        return NULL;
610    }
611    return ctx;
612}
613
614/*
615 * Get the primary random generator.
616 * Returns pointer to its EVP_RAND_CTX on success, NULL on failure.
617 *
618 */
619EVP_RAND_CTX *RAND_get0_primary(OSSL_LIB_CTX *ctx)
620{
621    RAND_GLOBAL *dgbl = rand_get_global(ctx);
622    EVP_RAND_CTX *ret;
623
624    if (dgbl == NULL)
625        return NULL;
626
627    if (!CRYPTO_THREAD_read_lock(dgbl->lock))
628        return NULL;
629
630    ret = dgbl->primary;
631    CRYPTO_THREAD_unlock(dgbl->lock);
632
633    if (ret != NULL)
634        return ret;
635
636    if (!CRYPTO_THREAD_write_lock(dgbl->lock))
637        return NULL;
638
639    ret = dgbl->primary;
640    if (ret != NULL) {
641        CRYPTO_THREAD_unlock(dgbl->lock);
642        return ret;
643    }
644
645#ifndef FIPS_MODULE
646    if (dgbl->seed == NULL) {
647        ERR_set_mark();
648        dgbl->seed = rand_new_seed(ctx);
649        ERR_pop_to_mark();
650    }
651#endif
652
653    ret = dgbl->primary = rand_new_drbg(ctx, dgbl->seed,
654                                        PRIMARY_RESEED_INTERVAL,
655                                        PRIMARY_RESEED_TIME_INTERVAL);
656    /*
657    * The primary DRBG may be shared between multiple threads so we must
658    * enable locking.
659    */
660    if (ret != NULL && !EVP_RAND_enable_locking(ret)) {
661        ERR_raise(ERR_LIB_EVP, EVP_R_UNABLE_TO_ENABLE_LOCKING);
662        EVP_RAND_CTX_free(ret);
663        ret = dgbl->primary = NULL;
664    }
665    CRYPTO_THREAD_unlock(dgbl->lock);
666
667    return ret;
668}
669
670/*
671 * Get the public random generator.
672 * Returns pointer to its EVP_RAND_CTX on success, NULL on failure.
673 */
674EVP_RAND_CTX *RAND_get0_public(OSSL_LIB_CTX *ctx)
675{
676    RAND_GLOBAL *dgbl = rand_get_global(ctx);
677    EVP_RAND_CTX *rand, *primary;
678
679    if (dgbl == NULL)
680        return NULL;
681
682    rand = CRYPTO_THREAD_get_local(&dgbl->public);
683    if (rand == NULL) {
684        primary = RAND_get0_primary(ctx);
685        if (primary == NULL)
686            return NULL;
687
688        ctx = ossl_lib_ctx_get_concrete(ctx);
689        /*
690         * If the private is also NULL then this is the first time we've
691         * used this thread.
692         */
693        if (CRYPTO_THREAD_get_local(&dgbl->private) == NULL
694                && !ossl_init_thread_start(NULL, ctx, rand_delete_thread_state))
695            return NULL;
696        rand = rand_new_drbg(ctx, primary, SECONDARY_RESEED_INTERVAL,
697                             SECONDARY_RESEED_TIME_INTERVAL);
698        CRYPTO_THREAD_set_local(&dgbl->public, rand);
699    }
700    return rand;
701}
702
703/*
704 * Get the private random generator.
705 * Returns pointer to its EVP_RAND_CTX on success, NULL on failure.
706 */
707EVP_RAND_CTX *RAND_get0_private(OSSL_LIB_CTX *ctx)
708{
709    RAND_GLOBAL *dgbl = rand_get_global(ctx);
710    EVP_RAND_CTX *rand, *primary;
711
712    if (dgbl == NULL)
713        return NULL;
714
715    rand = CRYPTO_THREAD_get_local(&dgbl->private);
716    if (rand == NULL) {
717        primary = RAND_get0_primary(ctx);
718        if (primary == NULL)
719            return NULL;
720
721        ctx = ossl_lib_ctx_get_concrete(ctx);
722        /*
723         * If the public is also NULL then this is the first time we've
724         * used this thread.
725         */
726        if (CRYPTO_THREAD_get_local(&dgbl->public) == NULL
727                && !ossl_init_thread_start(NULL, ctx, rand_delete_thread_state))
728            return NULL;
729        rand = rand_new_drbg(ctx, primary, SECONDARY_RESEED_INTERVAL,
730                             SECONDARY_RESEED_TIME_INTERVAL);
731        CRYPTO_THREAD_set_local(&dgbl->private, rand);
732    }
733    return rand;
734}
735
736#ifndef FIPS_MODULE
737static int random_set_string(char **p, const char *s)
738{
739    char *d = NULL;
740
741    if (s != NULL) {
742        d = OPENSSL_strdup(s);
743        if (d == NULL) {
744            ERR_raise(ERR_LIB_CRYPTO, ERR_R_MALLOC_FAILURE);
745            return 0;
746        }
747    }
748    OPENSSL_free(*p);
749    *p = d;
750    return 1;
751}
752
753/*
754 * Load the DRBG definitions from a configuration file.
755 */
756static int random_conf_init(CONF_IMODULE *md, const CONF *cnf)
757{
758    STACK_OF(CONF_VALUE) *elist;
759    CONF_VALUE *cval;
760    RAND_GLOBAL *dgbl = rand_get_global(NCONF_get0_libctx((CONF *)cnf));
761    int i, r = 1;
762
763    OSSL_TRACE1(CONF, "Loading random module: section %s\n",
764                CONF_imodule_get_value(md));
765
766    /* Value is a section containing RANDOM configuration */
767    elist = NCONF_get_section(cnf, CONF_imodule_get_value(md));
768    if (elist == NULL) {
769        ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_RANDOM_SECTION_ERROR);
770        return 0;
771    }
772
773    if (dgbl == NULL)
774        return 0;
775
776    for (i = 0; i < sk_CONF_VALUE_num(elist); i++) {
777        cval = sk_CONF_VALUE_value(elist, i);
778        if (OPENSSL_strcasecmp(cval->name, "random") == 0) {
779            if (!random_set_string(&dgbl->rng_name, cval->value))
780                return 0;
781        } else if (OPENSSL_strcasecmp(cval->name, "cipher") == 0) {
782            if (!random_set_string(&dgbl->rng_cipher, cval->value))
783                return 0;
784        } else if (OPENSSL_strcasecmp(cval->name, "digest") == 0) {
785            if (!random_set_string(&dgbl->rng_digest, cval->value))
786                return 0;
787        } else if (OPENSSL_strcasecmp(cval->name, "properties") == 0) {
788            if (!random_set_string(&dgbl->rng_propq, cval->value))
789                return 0;
790        } else if (OPENSSL_strcasecmp(cval->name, "seed") == 0) {
791            if (!random_set_string(&dgbl->seed_name, cval->value))
792                return 0;
793        } else if (OPENSSL_strcasecmp(cval->name, "seed_properties") == 0) {
794            if (!random_set_string(&dgbl->seed_propq, cval->value))
795                return 0;
796        } else {
797            ERR_raise_data(ERR_LIB_CRYPTO,
798                           CRYPTO_R_UNKNOWN_NAME_IN_RANDOM_SECTION,
799                           "name=%s, value=%s", cval->name, cval->value);
800            r = 0;
801        }
802    }
803    return r;
804}
805
806
807static void random_conf_deinit(CONF_IMODULE *md)
808{
809    OSSL_TRACE(CONF, "Cleaned up random\n");
810}
811
812void ossl_random_add_conf_module(void)
813{
814    OSSL_TRACE(CONF, "Adding config module 'random'\n");
815    CONF_module_add("random", random_conf_init, random_conf_deinit);
816}
817
818int RAND_set_DRBG_type(OSSL_LIB_CTX *ctx, const char *drbg, const char *propq,
819                       const char *cipher, const char *digest)
820{
821    RAND_GLOBAL *dgbl = rand_get_global(ctx);
822
823    if (dgbl == NULL)
824        return 0;
825    if (dgbl->primary != NULL) {
826        ERR_raise(ERR_LIB_CRYPTO, RAND_R_ALREADY_INSTANTIATED);
827        return 0;
828    }
829    return random_set_string(&dgbl->rng_name, drbg)
830        && random_set_string(&dgbl->rng_propq, propq)
831        && random_set_string(&dgbl->rng_cipher, cipher)
832        && random_set_string(&dgbl->rng_digest, digest);
833}
834
835int RAND_set_seed_source_type(OSSL_LIB_CTX *ctx, const char *seed,
836                              const char *propq)
837{
838    RAND_GLOBAL *dgbl = rand_get_global(ctx);
839
840    if (dgbl == NULL)
841        return 0;
842    if (dgbl->primary != NULL) {
843        ERR_raise(ERR_LIB_CRYPTO, RAND_R_ALREADY_INSTANTIATED);
844        return 0;
845    }
846    return random_set_string(&dgbl->seed_name, seed)
847        && random_set_string(&dgbl->seed_propq, propq);
848}
849
850#endif
851