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12fb8c3d | 1 | /* |
3c7d0945 | 2 | * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved. |
12fb8c3d RS |
3 | * |
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 | |
8 | */ | |
9 | ||
10 | #include <string.h> | |
11 | #include <openssl/crypto.h> | |
12 | #include <openssl/err.h> | |
13 | #include <openssl/rand.h> | |
14 | #include "rand_lcl.h" | |
0b14a5b7 KR |
15 | #include "internal/thread_once.h" |
16 | #include "internal/rand_int.h" | |
7caf122e | 17 | #include "internal/cryptlib_int.h" |
12fb8c3d RS |
18 | |
19 | /* | |
20 | * Support framework for NIST SP 800-90A DRBG, AES-CTR mode. | |
75e2c877 RS |
21 | * The RAND_DRBG is OpenSSL's pointer to an instance of the DRBG. |
22 | * | |
12fb8c3d RS |
23 | * The OpenSSL model is to have new and free functions, and that new |
24 | * does all initialization. That is not the NIST model, which has | |
25 | * instantiation and un-instantiate, and re-use within a new/free | |
26 | * lifecycle. (No doubt this comes from the desire to support hardware | |
27 | * DRBG, where allocation of resources on something like an HSM is | |
28 | * a much bigger deal than just re-setting an allocated resource.) | |
12fb8c3d RS |
29 | */ |
30 | ||
a93ba405 DMSP |
31 | /* |
32 | * THE THREE SHARED DRBGs | |
33 | * | |
34 | * There are three shared DRBGs (master, public and private), which are | |
35 | * accessed concurrently by all threads. | |
36 | * | |
37 | * THE MASTER DRBG | |
38 | * | |
39 | * Not used directly by the application, only for reseeding the two other | |
40 | * DRBGs. It reseeds itself by pulling either randomness from os entropy | |
41 | * sources or by consuming randomnes which was added by RAND_add() | |
42 | */ | |
933033b6 | 43 | static RAND_DRBG *drbg_master; |
a93ba405 DMSP |
44 | /*+ |
45 | * DRBG HIERARCHY | |
46 | * | |
47 | * In addition there are DRBGs, which are not shared, but used only by a | |
48 | * single thread at every time, for example the DRBGs which are owned by | |
49 | * an SSL context. All DRBGs are organized in a hierarchical fashion | |
50 | * with the <master> DRBG as root. | |
51 | * | |
52 | * This gives the following overall picture: | |
53 | * | |
54 | * <os entropy sources> | |
55 | * | | |
56 | * RAND_add() ==> <master> \ | |
57 | * / \ | shared DRBGs (with locking) | |
58 | * <public> <private> / | |
59 | * | | |
60 | * <ssl> owned by an SSL context | |
61 | * | |
62 | * AUTOMATIC RESEEDING | |
63 | * | |
08a65d96 DMSP |
64 | * Before satisfying a generate request, a DRBG reseeds itself automatically, |
65 | * if one of the following two conditions holds: | |
66 | * | |
67 | * - the number of generate requests since the last reseeding exceeds a | |
68 | * certain threshold, the so called |reseed_interval|. This behaviour | |
69 | * can be disabled by setting the |reseed_interval| to 0. | |
70 | * | |
71 | * - the time elapsed since the last reseeding exceeds a certain time | |
72 | * interval, the so called |reseed_time_interval|. This behaviour | |
73 | * can be disabled by setting the |reseed_time_interval| to 0. | |
a93ba405 DMSP |
74 | * |
75 | * MANUAL RESEEDING | |
76 | * | |
08a65d96 DMSP |
77 | * For the three shared DRBGs (and only for these) there is another way to |
78 | * reseed them manually by calling RAND_seed() (or RAND_add() with a positive | |
a93ba405 | 79 | * |randomness| argument). This will immediately reseed the <master> DRBG. |
08a65d96 DMSP |
80 | * The <public> and <private> DRBG will detect this on their next generate |
81 | * call and reseed, pulling randomness from <master>. | |
3ce1c27b DMSP |
82 | * |
83 | * LOCKING | |
84 | * | |
85 | * The three shared DRBGs are intended to be used concurrently, so they | |
812b1537 DMSP |
86 | * support locking. The RAND methods take the locks automatically, so using |
87 | * the RAND api (in particular RAND_bytes() and RAND_priv_bytes()) is | |
88 | * thread-safe. Note however that accessing the shared DRBGs directly via | |
89 | * the RAND_DRBG interface is *not* thread-safe. | |
90 | * | |
91 | * All other DRBG instances don't support locking, because they are | |
92 | * intendended to be used by a single thread. Instead of accessing a single | |
93 | * DRBG instance concurrently from different threads, it is recommended to | |
94 | * instantiate a separate DRBG instance per thread. Using the same shared | |
95 | * DRBG (preferrably the public DRBG) as parent of DRBG instances on | |
96 | * different threads is safe. | |
a93ba405 DMSP |
97 | */ |
98 | ||
99 | ||
100 | /* NIST SP 800-90A DRBG recommends the use of a personalization string. */ | |
101 | static const char ossl_pers_string[] = "OpenSSL NIST SP 800-90A DRBG"; | |
102 | ||
c16de9d8 | 103 | static CRYPTO_ONCE rand_drbg_init = CRYPTO_ONCE_STATIC_INIT; |
7caf122e KR |
104 | static CRYPTO_THREAD_LOCAL private_drbg_thread_local_key; |
105 | static CRYPTO_THREAD_LOCAL public_drbg_thread_local_key; | |
c16de9d8 | 106 | |
31393fd9 DMSP |
107 | |
108 | ||
109 | static int rand_drbg_type = RAND_DRBG_TYPE; | |
110 | static unsigned int rand_drbg_flags = RAND_DRBG_FLAGS; | |
111 | ||
4917e911 DMSP |
112 | static unsigned int master_reseed_interval = MASTER_RESEED_INTERVAL; |
113 | static unsigned int slave_reseed_interval = SLAVE_RESEED_INTERVAL; | |
114 | ||
115 | static time_t master_reseed_time_interval = MASTER_RESEED_TIME_INTERVAL; | |
116 | static time_t slave_reseed_time_interval = SLAVE_RESEED_TIME_INTERVAL; | |
117 | ||
63ab5ea1 | 118 | static RAND_DRBG *drbg_setup(RAND_DRBG *parent); |
4f9dabbf DMSP |
119 | |
120 | static RAND_DRBG *rand_drbg_new(int secure, | |
121 | int type, | |
122 | unsigned int flags, | |
123 | RAND_DRBG *parent); | |
0b14a5b7 | 124 | |
12fb8c3d | 125 | /* |
31393fd9 DMSP |
126 | * Set/initialize |drbg| to be of type |type|, with optional |flags|. |
127 | * | |
128 | * If |type| and |flags| are zero, use the defaults | |
efb8128a DMSP |
129 | * |
130 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 131 | */ |
31393fd9 | 132 | int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags) |
12fb8c3d RS |
133 | { |
134 | int ret = 1; | |
135 | ||
31393fd9 DMSP |
136 | if (type == 0 && flags == 0) { |
137 | type = rand_drbg_type; | |
138 | flags = rand_drbg_flags; | |
139 | } | |
140 | ||
75e2c877 RS |
141 | drbg->state = DRBG_UNINITIALISED; |
142 | drbg->flags = flags; | |
31393fd9 | 143 | drbg->type = type; |
12fb8c3d | 144 | |
31393fd9 | 145 | switch (type) { |
12fb8c3d RS |
146 | default: |
147 | RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE); | |
efb8128a | 148 | return 0; |
12fb8c3d RS |
149 | case 0: |
150 | /* Uninitialized; that's okay. */ | |
151 | return 1; | |
152 | case NID_aes_128_ctr: | |
153 | case NID_aes_192_ctr: | |
154 | case NID_aes_256_ctr: | |
8212d505 | 155 | ret = drbg_ctr_init(drbg); |
12fb8c3d RS |
156 | break; |
157 | } | |
158 | ||
efb8128a | 159 | if (ret == 0) |
12fb8c3d RS |
160 | RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG); |
161 | return ret; | |
162 | } | |
163 | ||
31393fd9 DMSP |
164 | /* |
165 | * Set/initialize default |type| and |flag| for new drbg instances. | |
166 | * | |
167 | * Returns 1 on success, 0 on failure. | |
168 | */ | |
169 | int RAND_DRBG_set_defaults(int type, unsigned int flags) | |
170 | { | |
171 | int ret = 1; | |
172 | ||
173 | switch (type) { | |
174 | default: | |
175 | RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_TYPE); | |
176 | return 0; | |
177 | case NID_aes_128_ctr: | |
178 | case NID_aes_192_ctr: | |
179 | case NID_aes_256_ctr: | |
180 | break; | |
181 | } | |
182 | ||
183 | if ((flags & ~RAND_DRBG_USED_FLAGS) != 0) { | |
184 | RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_FLAGS); | |
185 | return 0; | |
186 | } | |
187 | ||
188 | rand_drbg_type = type; | |
189 | rand_drbg_flags = flags; | |
190 | ||
191 | return ret; | |
192 | } | |
193 | ||
194 | ||
12fb8c3d | 195 | /* |
4f9dabbf DMSP |
196 | * Allocate memory and initialize a new DRBG. The DRBG is allocated on |
197 | * the secure heap if |secure| is nonzero and the secure heap is enabled. | |
198 | * The |parent|, if not NULL, will be used as random source for reseeding. | |
a93ba405 DMSP |
199 | * |
200 | * Returns a pointer to the new DRBG instance on success, NULL on failure. | |
12fb8c3d | 201 | */ |
4f9dabbf DMSP |
202 | static RAND_DRBG *rand_drbg_new(int secure, |
203 | int type, | |
204 | unsigned int flags, | |
205 | RAND_DRBG *parent) | |
12fb8c3d | 206 | { |
4f9dabbf DMSP |
207 | RAND_DRBG *drbg = secure ? |
208 | OPENSSL_secure_zalloc(sizeof(*drbg)) : OPENSSL_zalloc(sizeof(*drbg)); | |
12fb8c3d | 209 | |
9d951a78 | 210 | if (drbg == NULL) { |
12fb8c3d | 211 | RANDerr(RAND_F_RAND_DRBG_NEW, ERR_R_MALLOC_FAILURE); |
f96ff4e9 | 212 | return NULL; |
12fb8c3d | 213 | } |
4f9dabbf DMSP |
214 | |
215 | drbg->secure = secure && CRYPTO_secure_allocated(drbg); | |
a35f607c | 216 | drbg->fork_count = rand_fork_count; |
75e2c877 | 217 | drbg->parent = parent; |
4917e911 DMSP |
218 | |
219 | if (parent == NULL) { | |
220 | drbg->reseed_interval = master_reseed_interval; | |
221 | drbg->reseed_time_interval = master_reseed_time_interval; | |
222 | } else { | |
223 | drbg->reseed_interval = slave_reseed_interval; | |
224 | drbg->reseed_time_interval = slave_reseed_time_interval; | |
225 | } | |
226 | ||
efb8128a | 227 | if (RAND_DRBG_set(drbg, type, flags) == 0) |
75e2c877 RS |
228 | goto err; |
229 | ||
7caf122e KR |
230 | if (parent != NULL) { |
231 | rand_drbg_lock(parent); | |
232 | if (drbg->strength > parent->strength) { | |
233 | /* | |
234 | * We currently don't support the algorithm from NIST SP 800-90C | |
235 | * 10.1.2 to use a weaker DRBG as source | |
236 | */ | |
237 | rand_drbg_unlock(parent); | |
238 | RANDerr(RAND_F_RAND_DRBG_NEW, RAND_R_PARENT_STRENGTH_TOO_WEAK); | |
239 | goto err; | |
240 | } | |
241 | rand_drbg_unlock(parent); | |
35503b7c KR |
242 | } |
243 | ||
a93ba405 DMSP |
244 | if (!RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy, |
245 | rand_drbg_cleanup_entropy, | |
246 | NULL, NULL)) | |
247 | goto err; | |
75e2c877 RS |
248 | |
249 | return drbg; | |
250 | ||
251 | err: | |
4f9dabbf DMSP |
252 | if (drbg->secure) |
253 | OPENSSL_secure_free(drbg); | |
254 | else | |
255 | OPENSSL_free(drbg); | |
256 | ||
75e2c877 | 257 | return NULL; |
12fb8c3d RS |
258 | } |
259 | ||
4f9dabbf DMSP |
260 | RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent) |
261 | { | |
262 | return rand_drbg_new(0, type, flags, parent); | |
263 | } | |
264 | ||
265 | RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent) | |
266 | { | |
267 | return rand_drbg_new(1, type, flags, parent); | |
268 | } | |
269 | ||
12fb8c3d | 270 | /* |
75e2c877 | 271 | * Uninstantiate |drbg| and free all memory. |
12fb8c3d | 272 | */ |
75e2c877 | 273 | void RAND_DRBG_free(RAND_DRBG *drbg) |
12fb8c3d | 274 | { |
c16de9d8 | 275 | if (drbg == NULL) |
12fb8c3d RS |
276 | return; |
277 | ||
8212d505 DMSP |
278 | if (drbg->meth != NULL) |
279 | drbg->meth->uninstantiate(drbg); | |
4f9dabbf | 280 | CRYPTO_THREAD_lock_free(drbg->lock); |
75e2c877 | 281 | CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data); |
4f9dabbf DMSP |
282 | |
283 | if (drbg->secure) | |
284 | OPENSSL_secure_clear_free(drbg, sizeof(*drbg)); | |
285 | else | |
286 | OPENSSL_clear_free(drbg, sizeof(*drbg)); | |
12fb8c3d RS |
287 | } |
288 | ||
289 | /* | |
75e2c877 | 290 | * Instantiate |drbg|, after it has been initialized. Use |pers| and |
12fb8c3d | 291 | * |perslen| as prediction-resistance input. |
2139145b BK |
292 | * |
293 | * Requires that drbg->lock is already locked for write, if non-null. | |
efb8128a DMSP |
294 | * |
295 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 296 | */ |
75e2c877 | 297 | int RAND_DRBG_instantiate(RAND_DRBG *drbg, |
12fb8c3d RS |
298 | const unsigned char *pers, size_t perslen) |
299 | { | |
12fb8c3d | 300 | unsigned char *nonce = NULL, *entropy = NULL; |
aa048aef | 301 | size_t noncelen = 0, entropylen = 0; |
12fb8c3d | 302 | |
aa048aef | 303 | if (perslen > drbg->max_perslen) { |
75e2c877 RS |
304 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, |
305 | RAND_R_PERSONALISATION_STRING_TOO_LONG); | |
12fb8c3d RS |
306 | goto end; |
307 | } | |
8212d505 DMSP |
308 | |
309 | if (drbg->meth == NULL) | |
310 | { | |
311 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, | |
312 | RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED); | |
313 | goto end; | |
314 | } | |
315 | ||
75e2c877 RS |
316 | if (drbg->state != DRBG_UNINITIALISED) { |
317 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, | |
318 | drbg->state == DRBG_ERROR ? RAND_R_IN_ERROR_STATE | |
319 | : RAND_R_ALREADY_INSTANTIATED); | |
12fb8c3d RS |
320 | goto end; |
321 | } | |
322 | ||
75e2c877 RS |
323 | drbg->state = DRBG_ERROR; |
324 | if (drbg->get_entropy != NULL) | |
aa048aef | 325 | entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength, |
eb238134 KR |
326 | drbg->min_entropylen, |
327 | drbg->max_entropylen, 0); | |
c16de9d8 DMSP |
328 | if (entropylen < drbg->min_entropylen |
329 | || entropylen > drbg->max_entropylen) { | |
75e2c877 | 330 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_ENTROPY); |
12fb8c3d RS |
331 | goto end; |
332 | } | |
333 | ||
aa048aef | 334 | if (drbg->max_noncelen > 0 && drbg->get_nonce != NULL) { |
75e2c877 | 335 | noncelen = drbg->get_nonce(drbg, &nonce, drbg->strength / 2, |
aa048aef DMSP |
336 | drbg->min_noncelen, drbg->max_noncelen); |
337 | if (noncelen < drbg->min_noncelen || noncelen > drbg->max_noncelen) { | |
c16de9d8 DMSP |
338 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, |
339 | RAND_R_ERROR_RETRIEVING_NONCE); | |
12fb8c3d RS |
340 | goto end; |
341 | } | |
342 | } | |
343 | ||
8212d505 | 344 | if (!drbg->meth->instantiate(drbg, entropy, entropylen, |
12fb8c3d | 345 | nonce, noncelen, pers, perslen)) { |
75e2c877 | 346 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_INSTANTIATING_DRBG); |
12fb8c3d RS |
347 | goto end; |
348 | } | |
349 | ||
75e2c877 | 350 | drbg->state = DRBG_READY; |
a93ba405 | 351 | drbg->generate_counter = 0; |
08a65d96 | 352 | drbg->reseed_time = time(NULL); |
a93ba405 DMSP |
353 | if (drbg->reseed_counter > 0) { |
354 | if (drbg->parent == NULL) | |
355 | drbg->reseed_counter++; | |
356 | else | |
357 | drbg->reseed_counter = drbg->parent->reseed_counter; | |
358 | } | |
12fb8c3d RS |
359 | |
360 | end: | |
75e2c877 | 361 | if (entropy != NULL && drbg->cleanup_entropy != NULL) |
6969a3f4 | 362 | drbg->cleanup_entropy(drbg, entropy, entropylen); |
75e2c877 | 363 | if (nonce != NULL && drbg->cleanup_nonce!= NULL ) |
6969a3f4 | 364 | drbg->cleanup_nonce(drbg, nonce, noncelen); |
c16de9d8 DMSP |
365 | if (drbg->pool != NULL) { |
366 | if (drbg->state == DRBG_READY) { | |
367 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, | |
368 | RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED); | |
369 | drbg->state = DRBG_ERROR; | |
370 | } | |
6decf943 | 371 | rand_pool_free(drbg->pool); |
c16de9d8 DMSP |
372 | drbg->pool = NULL; |
373 | } | |
75e2c877 | 374 | if (drbg->state == DRBG_READY) |
12fb8c3d | 375 | return 1; |
12fb8c3d RS |
376 | return 0; |
377 | } | |
378 | ||
379 | /* | |
75e2c877 | 380 | * Uninstantiate |drbg|. Must be instantiated before it can be used. |
2139145b BK |
381 | * |
382 | * Requires that drbg->lock is already locked for write, if non-null. | |
efb8128a DMSP |
383 | * |
384 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 385 | */ |
75e2c877 | 386 | int RAND_DRBG_uninstantiate(RAND_DRBG *drbg) |
12fb8c3d | 387 | { |
8212d505 DMSP |
388 | if (drbg->meth == NULL) |
389 | { | |
390 | RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE, | |
391 | RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED); | |
392 | return 0; | |
393 | } | |
394 | ||
efb8128a DMSP |
395 | /* Clear the entire drbg->ctr struct, then reset some important |
396 | * members of the drbg->ctr struct (e.g. keysize, df_ks) to their | |
397 | * initial values. | |
398 | */ | |
8212d505 | 399 | drbg->meth->uninstantiate(drbg); |
31393fd9 | 400 | return RAND_DRBG_set(drbg, drbg->type, drbg->flags); |
12fb8c3d RS |
401 | } |
402 | ||
403 | /* | |
c16de9d8 | 404 | * Reseed |drbg|, mixing in the specified data |
2139145b BK |
405 | * |
406 | * Requires that drbg->lock is already locked for write, if non-null. | |
efb8128a DMSP |
407 | * |
408 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 409 | */ |
75e2c877 | 410 | int RAND_DRBG_reseed(RAND_DRBG *drbg, |
eb238134 KR |
411 | const unsigned char *adin, size_t adinlen, |
412 | int prediction_resistance) | |
12fb8c3d RS |
413 | { |
414 | unsigned char *entropy = NULL; | |
aa048aef | 415 | size_t entropylen = 0; |
75e2c877 RS |
416 | |
417 | if (drbg->state == DRBG_ERROR) { | |
418 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_IN_ERROR_STATE); | |
419 | return 0; | |
420 | } | |
421 | if (drbg->state == DRBG_UNINITIALISED) { | |
422 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_NOT_INSTANTIATED); | |
423 | return 0; | |
12fb8c3d RS |
424 | } |
425 | ||
426 | if (adin == NULL) | |
427 | adinlen = 0; | |
aa048aef | 428 | else if (adinlen > drbg->max_adinlen) { |
75e2c877 RS |
429 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ADDITIONAL_INPUT_TOO_LONG); |
430 | return 0; | |
12fb8c3d RS |
431 | } |
432 | ||
75e2c877 RS |
433 | drbg->state = DRBG_ERROR; |
434 | if (drbg->get_entropy != NULL) | |
aa048aef | 435 | entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength, |
eb238134 KR |
436 | drbg->min_entropylen, |
437 | drbg->max_entropylen, | |
438 | prediction_resistance); | |
c16de9d8 DMSP |
439 | if (entropylen < drbg->min_entropylen |
440 | || entropylen > drbg->max_entropylen) { | |
75e2c877 | 441 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ERROR_RETRIEVING_ENTROPY); |
12fb8c3d RS |
442 | goto end; |
443 | } | |
444 | ||
8212d505 | 445 | if (!drbg->meth->reseed(drbg, entropy, entropylen, adin, adinlen)) |
12fb8c3d | 446 | goto end; |
a93ba405 | 447 | |
75e2c877 | 448 | drbg->state = DRBG_READY; |
a93ba405 | 449 | drbg->generate_counter = 0; |
08a65d96 | 450 | drbg->reseed_time = time(NULL); |
a93ba405 DMSP |
451 | if (drbg->reseed_counter > 0) { |
452 | if (drbg->parent == NULL) | |
453 | drbg->reseed_counter++; | |
454 | else | |
455 | drbg->reseed_counter = drbg->parent->reseed_counter; | |
456 | } | |
12fb8c3d RS |
457 | |
458 | end: | |
75e2c877 | 459 | if (entropy != NULL && drbg->cleanup_entropy != NULL) |
6969a3f4 | 460 | drbg->cleanup_entropy(drbg, entropy, entropylen); |
75e2c877 | 461 | if (drbg->state == DRBG_READY) |
12fb8c3d | 462 | return 1; |
12fb8c3d RS |
463 | return 0; |
464 | } | |
465 | ||
c16de9d8 DMSP |
466 | /* |
467 | * Restart |drbg|, using the specified entropy or additional input | |
468 | * | |
469 | * Tries its best to get the drbg instantiated by all means, | |
470 | * regardless of its current state. | |
471 | * | |
472 | * Optionally, a |buffer| of |len| random bytes can be passed, | |
473 | * which is assumed to contain at least |entropy| bits of entropy. | |
474 | * | |
475 | * If |entropy| > 0, the buffer content is used as entropy input. | |
476 | * | |
477 | * If |entropy| == 0, the buffer content is used as additional input | |
478 | * | |
479 | * Returns 1 on success, 0 on failure. | |
480 | * | |
481 | * This function is used internally only. | |
482 | */ | |
483 | int rand_drbg_restart(RAND_DRBG *drbg, | |
484 | const unsigned char *buffer, size_t len, size_t entropy) | |
485 | { | |
486 | int reseeded = 0; | |
487 | const unsigned char *adin = NULL; | |
488 | size_t adinlen = 0; | |
489 | ||
490 | if (drbg->pool != NULL) { | |
491 | RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR); | |
6decf943 | 492 | rand_pool_free(drbg->pool); |
c16de9d8 DMSP |
493 | drbg->pool = NULL; |
494 | } | |
495 | ||
496 | if (buffer != NULL) { | |
497 | if (entropy > 0) { | |
498 | if (drbg->max_entropylen < len) { | |
499 | RANDerr(RAND_F_RAND_DRBG_RESTART, | |
500 | RAND_R_ENTROPY_INPUT_TOO_LONG); | |
501 | return 0; | |
502 | } | |
503 | ||
504 | if (entropy > 8 * len) { | |
505 | RANDerr(RAND_F_RAND_DRBG_RESTART, RAND_R_ENTROPY_OUT_OF_RANGE); | |
506 | return 0; | |
507 | } | |
508 | ||
509 | /* will be picked up by the rand_drbg_get_entropy() callback */ | |
6decf943 | 510 | drbg->pool = rand_pool_new(entropy, len, len); |
c16de9d8 DMSP |
511 | if (drbg->pool == NULL) |
512 | return 0; | |
513 | ||
6decf943 | 514 | rand_pool_add(drbg->pool, buffer, len, entropy); |
c16de9d8 DMSP |
515 | } else { |
516 | if (drbg->max_adinlen < len) { | |
517 | RANDerr(RAND_F_RAND_DRBG_RESTART, | |
518 | RAND_R_ADDITIONAL_INPUT_TOO_LONG); | |
519 | return 0; | |
520 | } | |
521 | adin = buffer; | |
522 | adinlen = len; | |
523 | } | |
524 | } | |
525 | ||
526 | /* repair error state */ | |
efb8128a | 527 | if (drbg->state == DRBG_ERROR) |
c16de9d8 DMSP |
528 | RAND_DRBG_uninstantiate(drbg); |
529 | ||
530 | /* repair uninitialized state */ | |
531 | if (drbg->state == DRBG_UNINITIALISED) { | |
a93ba405 DMSP |
532 | /* reinstantiate drbg */ |
533 | RAND_DRBG_instantiate(drbg, | |
534 | (const unsigned char *) ossl_pers_string, | |
535 | sizeof(ossl_pers_string) - 1); | |
c16de9d8 DMSP |
536 | /* already reseeded. prevent second reseeding below */ |
537 | reseeded = (drbg->state == DRBG_READY); | |
538 | } | |
539 | ||
540 | /* refresh current state if entropy or additional input has been provided */ | |
541 | if (drbg->state == DRBG_READY) { | |
542 | if (adin != NULL) { | |
543 | /* | |
544 | * mix in additional input without reseeding | |
545 | * | |
546 | * Similar to RAND_DRBG_reseed(), but the provided additional | |
547 | * data |adin| is mixed into the current state without pulling | |
548 | * entropy from the trusted entropy source using get_entropy(). | |
549 | * This is not a reseeding in the strict sense of NIST SP 800-90A. | |
550 | */ | |
8212d505 | 551 | drbg->meth->reseed(drbg, adin, adinlen, NULL, 0); |
c16de9d8 DMSP |
552 | } else if (reseeded == 0) { |
553 | /* do a full reseeding if it has not been done yet above */ | |
eb238134 | 554 | RAND_DRBG_reseed(drbg, NULL, 0, 0); |
c16de9d8 DMSP |
555 | } |
556 | } | |
557 | ||
558 | /* check whether a given entropy pool was cleared properly during reseed */ | |
559 | if (drbg->pool != NULL) { | |
560 | drbg->state = DRBG_ERROR; | |
561 | RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR); | |
6decf943 | 562 | rand_pool_free(drbg->pool); |
c16de9d8 DMSP |
563 | drbg->pool = NULL; |
564 | return 0; | |
565 | } | |
566 | ||
567 | return drbg->state == DRBG_READY; | |
568 | } | |
569 | ||
12fb8c3d RS |
570 | /* |
571 | * Generate |outlen| bytes into the buffer at |out|. Reseed if we need | |
572 | * to or if |prediction_resistance| is set. Additional input can be | |
573 | * sent in |adin| and |adinlen|. | |
c16de9d8 | 574 | * |
2139145b BK |
575 | * Requires that drbg->lock is already locked for write, if non-null. |
576 | * | |
c16de9d8 DMSP |
577 | * Returns 1 on success, 0 on failure. |
578 | * | |
12fb8c3d | 579 | */ |
75e2c877 | 580 | int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen, |
12fb8c3d RS |
581 | int prediction_resistance, |
582 | const unsigned char *adin, size_t adinlen) | |
583 | { | |
e0b625f9 DMSP |
584 | int reseed_required = 0; |
585 | ||
c16de9d8 DMSP |
586 | if (drbg->state != DRBG_READY) { |
587 | /* try to recover from previous errors */ | |
588 | rand_drbg_restart(drbg, NULL, 0, 0); | |
589 | ||
590 | if (drbg->state == DRBG_ERROR) { | |
591 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_IN_ERROR_STATE); | |
592 | return 0; | |
593 | } | |
594 | if (drbg->state == DRBG_UNINITIALISED) { | |
595 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_NOT_INSTANTIATED); | |
596 | return 0; | |
597 | } | |
12fb8c3d | 598 | } |
c16de9d8 | 599 | |
75e2c877 RS |
600 | if (outlen > drbg->max_request) { |
601 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG); | |
602 | return 0; | |
603 | } | |
aa048aef | 604 | if (adinlen > drbg->max_adinlen) { |
75e2c877 RS |
605 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_ADDITIONAL_INPUT_TOO_LONG); |
606 | return 0; | |
12fb8c3d RS |
607 | } |
608 | ||
a35f607c RS |
609 | if (drbg->fork_count != rand_fork_count) { |
610 | drbg->fork_count = rand_fork_count; | |
e0b625f9 | 611 | reseed_required = 1; |
a35f607c RS |
612 | } |
613 | ||
a93ba405 DMSP |
614 | if (drbg->reseed_interval > 0) { |
615 | if (drbg->generate_counter >= drbg->reseed_interval) | |
616 | reseed_required = 1; | |
617 | } | |
08a65d96 DMSP |
618 | if (drbg->reseed_time_interval > 0) { |
619 | time_t now = time(NULL); | |
620 | if (now < drbg->reseed_time | |
621 | || now - drbg->reseed_time >= drbg->reseed_time_interval) | |
622 | reseed_required = 1; | |
623 | } | |
a93ba405 DMSP |
624 | if (drbg->reseed_counter > 0 && drbg->parent != NULL) { |
625 | if (drbg->reseed_counter != drbg->parent->reseed_counter) | |
626 | reseed_required = 1; | |
627 | } | |
12fb8c3d | 628 | |
e0b625f9 | 629 | if (reseed_required || prediction_resistance) { |
eb238134 | 630 | if (!RAND_DRBG_reseed(drbg, adin, adinlen, prediction_resistance)) { |
75e2c877 RS |
631 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_RESEED_ERROR); |
632 | return 0; | |
12fb8c3d RS |
633 | } |
634 | adin = NULL; | |
635 | adinlen = 0; | |
636 | } | |
637 | ||
8212d505 | 638 | if (!drbg->meth->generate(drbg, out, outlen, adin, adinlen)) { |
75e2c877 RS |
639 | drbg->state = DRBG_ERROR; |
640 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_GENERATE_ERROR); | |
641 | return 0; | |
12fb8c3d | 642 | } |
75e2c877 | 643 | |
a93ba405 | 644 | drbg->generate_counter++; |
e0b625f9 | 645 | |
12fb8c3d | 646 | return 1; |
12fb8c3d RS |
647 | } |
648 | ||
20928ff6 KR |
649 | /* |
650 | * Generates |outlen| random bytes and stores them in |out|. It will | |
651 | * using the given |drbg| to generate the bytes. | |
652 | * | |
653 | * Requires that drbg->lock is already locked for write, if non-null. | |
654 | * | |
655 | * Returns 1 on success 0 on failure. | |
656 | */ | |
657 | int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen) | |
658 | { | |
659 | unsigned char *additional = NULL; | |
660 | size_t additional_len; | |
1648338b | 661 | size_t chunk; |
20928ff6 KR |
662 | size_t ret; |
663 | ||
664 | additional_len = rand_drbg_get_additional_data(&additional, drbg->max_adinlen); | |
1648338b DMSP |
665 | |
666 | for ( ; outlen > 0; outlen -= chunk, out += chunk) { | |
667 | chunk = outlen; | |
668 | if (chunk > drbg->max_request) | |
669 | chunk = drbg->max_request; | |
670 | ret = RAND_DRBG_generate(drbg, out, chunk, 0, additional, additional_len); | |
671 | if (!ret) | |
672 | goto err; | |
673 | } | |
674 | ret = 1; | |
675 | ||
676 | err: | |
20928ff6 KR |
677 | if (additional_len != 0) |
678 | OPENSSL_secure_clear_free(additional, additional_len); | |
679 | ||
680 | return ret; | |
681 | } | |
682 | ||
12fb8c3d | 683 | /* |
c16de9d8 DMSP |
684 | * Set the RAND_DRBG callbacks for obtaining entropy and nonce. |
685 | * | |
686 | * In the following, the signature and the semantics of the | |
687 | * get_entropy() and cleanup_entropy() callbacks are explained. | |
688 | * | |
689 | * GET_ENTROPY | |
690 | * | |
691 | * size_t get_entropy(RAND_DRBG *ctx, | |
692 | * unsigned char **pout, | |
693 | * int entropy, | |
694 | * size_t min_len, size_t max_len); | |
695 | * | |
696 | * This is a request to allocate and fill a buffer of size | |
697 | * |min_len| <= size <= |max_len| (in bytes) which contains | |
698 | * at least |entropy| bits of randomness. The buffer's address is | |
699 | * to be returned in |*pout| and the number of collected | |
700 | * randomness bytes (which may be less than the allocated size | |
701 | * of the buffer) as return value. | |
702 | * | |
703 | * If the callback fails to acquire at least |entropy| bits of | |
704 | * randomness, it shall return a buffer length of 0. | |
705 | * | |
706 | * CLEANUP_ENTROPY | |
707 | * | |
708 | * void cleanup_entropy(RAND_DRBG *ctx, | |
709 | * unsigned char *out, size_t outlen); | |
710 | * | |
711 | * A request to clear and free the buffer allocated by get_entropy(). | |
712 | * The values |out| and |outlen| are expected to be the random buffer's | |
713 | * address and length, as returned by the get_entropy() callback. | |
714 | * | |
715 | * GET_NONCE, CLEANUP_NONCE | |
716 | * | |
717 | * Signature and semantics of the get_nonce() and cleanup_nonce() | |
718 | * callbacks are analogous to get_entropy() and cleanup_entropy(). | |
719 | * Currently, the nonce is used only for the known answer tests. | |
12fb8c3d | 720 | */ |
75e2c877 | 721 | int RAND_DRBG_set_callbacks(RAND_DRBG *drbg, |
c16de9d8 DMSP |
722 | RAND_DRBG_get_entropy_fn get_entropy, |
723 | RAND_DRBG_cleanup_entropy_fn cleanup_entropy, | |
724 | RAND_DRBG_get_nonce_fn get_nonce, | |
725 | RAND_DRBG_cleanup_nonce_fn cleanup_nonce) | |
12fb8c3d | 726 | { |
75e2c877 | 727 | if (drbg->state != DRBG_UNINITIALISED) |
12fb8c3d | 728 | return 0; |
c16de9d8 DMSP |
729 | drbg->get_entropy = get_entropy; |
730 | drbg->cleanup_entropy = cleanup_entropy; | |
731 | drbg->get_nonce = get_nonce; | |
732 | drbg->cleanup_nonce = cleanup_nonce; | |
12fb8c3d RS |
733 | return 1; |
734 | } | |
735 | ||
736 | /* | |
75e2c877 | 737 | * Set the reseed interval. |
a93ba405 DMSP |
738 | * |
739 | * The drbg will reseed automatically whenever the number of generate | |
740 | * requests exceeds the given reseed interval. If the reseed interval | |
08a65d96 | 741 | * is 0, then this feature is disabled. |
a93ba405 DMSP |
742 | * |
743 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 744 | */ |
a93ba405 | 745 | int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval) |
12fb8c3d | 746 | { |
a93ba405 | 747 | if (interval > MAX_RESEED_INTERVAL) |
4c75ee85 | 748 | return 0; |
75e2c877 | 749 | drbg->reseed_interval = interval; |
4c75ee85 | 750 | return 1; |
12fb8c3d RS |
751 | } |
752 | ||
08a65d96 DMSP |
753 | /* |
754 | * Set the reseed time interval. | |
755 | * | |
756 | * The drbg will reseed automatically whenever the time elapsed since | |
757 | * the last reseeding exceeds the given reseed time interval. For safety, | |
758 | * a reseeding will also occur if the clock has been reset to a smaller | |
759 | * value. | |
760 | * | |
761 | * Returns 1 on success, 0 on failure. | |
762 | */ | |
763 | int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval) | |
764 | { | |
765 | if (interval > MAX_RESEED_TIME_INTERVAL) | |
766 | return 0; | |
767 | drbg->reseed_time_interval = interval; | |
768 | return 1; | |
769 | } | |
770 | ||
4917e911 DMSP |
771 | /* |
772 | * Set the default values for reseed (time) intervals of new DRBG instances | |
773 | * | |
774 | * The default values can be set independently for master DRBG instances | |
775 | * (without a parent) and slave DRBG instances (with parent). | |
776 | * | |
777 | * Returns 1 on success, 0 on failure. | |
778 | */ | |
779 | ||
780 | int RAND_DRBG_set_reseed_defaults( | |
781 | unsigned int _master_reseed_interval, | |
782 | unsigned int _slave_reseed_interval, | |
783 | time_t _master_reseed_time_interval, | |
784 | time_t _slave_reseed_time_interval | |
785 | ) | |
786 | { | |
787 | if (_master_reseed_interval > MAX_RESEED_INTERVAL | |
788 | || _slave_reseed_interval > MAX_RESEED_INTERVAL) | |
789 | return 0; | |
790 | ||
791 | if (_master_reseed_time_interval > MAX_RESEED_TIME_INTERVAL | |
792 | || _slave_reseed_time_interval > MAX_RESEED_TIME_INTERVAL) | |
793 | return 0; | |
794 | ||
795 | master_reseed_interval = _master_reseed_interval; | |
796 | slave_reseed_interval = _slave_reseed_interval; | |
797 | ||
798 | master_reseed_time_interval = _master_reseed_time_interval; | |
799 | slave_reseed_time_interval = _slave_reseed_time_interval; | |
800 | ||
801 | return 1; | |
802 | } | |
3ce1c27b DMSP |
803 | |
804 | /* | |
805 | * Locks the given drbg. Locking a drbg which does not have locking | |
806 | * enabled is considered a successful no-op. | |
807 | * | |
808 | * Returns 1 on success, 0 on failure. | |
809 | */ | |
812b1537 | 810 | int rand_drbg_lock(RAND_DRBG *drbg) |
3ce1c27b DMSP |
811 | { |
812 | if (drbg->lock != NULL) | |
813 | return CRYPTO_THREAD_write_lock(drbg->lock); | |
814 | ||
815 | return 1; | |
816 | } | |
817 | ||
818 | /* | |
819 | * Unlocks the given drbg. Unlocking a drbg which does not have locking | |
820 | * enabled is considered a successful no-op. | |
821 | * | |
822 | * Returns 1 on success, 0 on failure. | |
823 | */ | |
812b1537 | 824 | int rand_drbg_unlock(RAND_DRBG *drbg) |
3ce1c27b DMSP |
825 | { |
826 | if (drbg->lock != NULL) | |
827 | return CRYPTO_THREAD_unlock(drbg->lock); | |
828 | ||
829 | return 1; | |
830 | } | |
831 | ||
832 | /* | |
833 | * Enables locking for the given drbg | |
834 | * | |
835 | * Locking can only be enabled if the random generator | |
836 | * is in the uninitialized state. | |
837 | * | |
838 | * Returns 1 on success, 0 on failure. | |
839 | */ | |
812b1537 | 840 | int rand_drbg_enable_locking(RAND_DRBG *drbg) |
3ce1c27b DMSP |
841 | { |
842 | if (drbg->state != DRBG_UNINITIALISED) { | |
843 | RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, | |
844 | RAND_R_DRBG_ALREADY_INITIALIZED); | |
845 | return 0; | |
846 | } | |
847 | ||
848 | if (drbg->lock == NULL) { | |
4f9dabbf | 849 | if (drbg->parent != NULL && drbg->parent->lock == NULL) { |
3ce1c27b DMSP |
850 | RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, |
851 | RAND_R_PARENT_LOCKING_NOT_ENABLED); | |
852 | return 0; | |
853 | } | |
854 | ||
855 | drbg->lock = CRYPTO_THREAD_lock_new(); | |
856 | if (drbg->lock == NULL) { | |
857 | RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, | |
858 | RAND_R_FAILED_TO_CREATE_LOCK); | |
859 | return 0; | |
860 | } | |
861 | } | |
862 | ||
863 | return 1; | |
864 | } | |
865 | ||
12fb8c3d RS |
866 | /* |
867 | * Get and set the EXDATA | |
868 | */ | |
75e2c877 RS |
869 | int RAND_DRBG_set_ex_data(RAND_DRBG *drbg, int idx, void *arg) |
870 | { | |
871 | return CRYPTO_set_ex_data(&drbg->ex_data, idx, arg); | |
872 | } | |
873 | ||
874 | void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx) | |
875 | { | |
876 | return CRYPTO_get_ex_data(&drbg->ex_data, idx); | |
877 | } | |
878 | ||
879 | ||
880 | /* | |
881 | * The following functions provide a RAND_METHOD that works on the | |
882 | * global DRBG. They lock. | |
883 | */ | |
884 | ||
0b14a5b7 | 885 | /* |
933033b6 DMSP |
886 | * Allocates a new global DRBG on the secure heap (if enabled) and |
887 | * initializes it with default settings. | |
a93ba405 DMSP |
888 | * |
889 | * Returns a pointer to the new DRBG instance on success, NULL on failure. | |
0b14a5b7 | 890 | */ |
63ab5ea1 | 891 | static RAND_DRBG *drbg_setup(RAND_DRBG *parent) |
0b14a5b7 | 892 | { |
933033b6 | 893 | RAND_DRBG *drbg; |
0b14a5b7 | 894 | |
31393fd9 | 895 | drbg = RAND_DRBG_secure_new(rand_drbg_type, rand_drbg_flags, parent); |
933033b6 DMSP |
896 | if (drbg == NULL) |
897 | return NULL; | |
898 | ||
7caf122e KR |
899 | /* Only the master DRBG needs to have a lock */ |
900 | if (parent == NULL && rand_drbg_enable_locking(drbg) == 0) | |
933033b6 | 901 | goto err; |
a93ba405 | 902 | |
a93ba405 DMSP |
903 | /* enable seed propagation */ |
904 | drbg->reseed_counter = 1; | |
905 | ||
c16de9d8 DMSP |
906 | /* |
907 | * Ignore instantiation error so support just-in-time instantiation. | |
908 | * | |
909 | * The state of the drbg will be checked in RAND_DRBG_generate() and | |
910 | * an automatic recovery is attempted. | |
911 | */ | |
912 | RAND_DRBG_instantiate(drbg, | |
913 | (const unsigned char *) ossl_pers_string, | |
914 | sizeof(ossl_pers_string) - 1); | |
933033b6 DMSP |
915 | return drbg; |
916 | ||
917 | err: | |
4f9dabbf | 918 | RAND_DRBG_free(drbg); |
933033b6 | 919 | return NULL; |
0b14a5b7 KR |
920 | } |
921 | ||
922 | /* | |
923 | * Initialize the global DRBGs on first use. | |
924 | * Returns 1 on success, 0 on failure. | |
925 | */ | |
c16de9d8 | 926 | DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init) |
0b14a5b7 | 927 | { |
7caf122e KR |
928 | int ret = 1; |
929 | ||
39571fca DMSP |
930 | /* |
931 | * ensure that libcrypto is initialized, otherwise the | |
932 | * DRBG locks are not cleaned up properly | |
933 | */ | |
934 | if (!OPENSSL_init_crypto(0, NULL)) | |
935 | return 0; | |
936 | ||
7caf122e KR |
937 | ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND); |
938 | ||
63ab5ea1 | 939 | drbg_master = drbg_setup(NULL); |
0b14a5b7 | 940 | |
7caf122e KR |
941 | ret &= CRYPTO_THREAD_init_local(&private_drbg_thread_local_key, NULL); |
942 | ret &= CRYPTO_THREAD_init_local(&public_drbg_thread_local_key, NULL); | |
943 | ||
944 | if (drbg_master == NULL || ret == 0) | |
933033b6 | 945 | return 0; |
0b14a5b7 | 946 | |
933033b6 | 947 | return 1; |
0b14a5b7 KR |
948 | } |
949 | ||
0b14a5b7 | 950 | /* Clean up the global DRBGs before exit */ |
c16de9d8 | 951 | void rand_drbg_cleanup_int(void) |
0b14a5b7 | 952 | { |
4f9dabbf | 953 | RAND_DRBG_free(drbg_master); |
7caf122e | 954 | drbg_master = NULL; |
933033b6 | 955 | |
7caf122e KR |
956 | CRYPTO_THREAD_cleanup_local(&private_drbg_thread_local_key); |
957 | CRYPTO_THREAD_cleanup_local(&public_drbg_thread_local_key); | |
958 | } | |
959 | ||
960 | void drbg_delete_thread_state() | |
961 | { | |
962 | RAND_DRBG *drbg; | |
963 | ||
964 | drbg = CRYPTO_THREAD_get_local(&public_drbg_thread_local_key); | |
965 | RAND_DRBG_free(drbg); | |
966 | ||
967 | drbg = CRYPTO_THREAD_get_local(&private_drbg_thread_local_key); | |
968 | RAND_DRBG_free(drbg); | |
0b14a5b7 KR |
969 | } |
970 | ||
c16de9d8 | 971 | /* Implements the default OpenSSL RAND_bytes() method */ |
75e2c877 RS |
972 | static int drbg_bytes(unsigned char *out, int count) |
973 | { | |
f61f62ea | 974 | int ret; |
a93ba405 | 975 | RAND_DRBG *drbg = RAND_DRBG_get0_public(); |
75e2c877 | 976 | |
0b14a5b7 KR |
977 | if (drbg == NULL) |
978 | return 0; | |
979 | ||
f61f62ea | 980 | ret = RAND_DRBG_bytes(drbg, out, count); |
f61f62ea | 981 | |
75e2c877 RS |
982 | return ret; |
983 | } | |
984 | ||
c16de9d8 | 985 | /* Implements the default OpenSSL RAND_add() method */ |
75e2c877 RS |
986 | static int drbg_add(const void *buf, int num, double randomness) |
987 | { | |
c16de9d8 | 988 | int ret = 0; |
a93ba405 | 989 | RAND_DRBG *drbg = RAND_DRBG_get0_master(); |
75e2c877 | 990 | |
c16de9d8 DMSP |
991 | if (drbg == NULL) |
992 | return 0; | |
75e2c877 | 993 | |
c16de9d8 DMSP |
994 | if (num < 0 || randomness < 0.0) |
995 | return 0; | |
75e2c877 | 996 | |
c16de9d8 DMSP |
997 | if (randomness > (double)drbg->max_entropylen) { |
998 | /* | |
999 | * The purpose of this check is to bound |randomness| by a | |
1000 | * relatively small value in order to prevent an integer | |
1001 | * overflow when multiplying by 8 in the rand_drbg_restart() | |
1002 | * call below. | |
1003 | */ | |
1004 | return 0; | |
75e2c877 RS |
1005 | } |
1006 | ||
812b1537 | 1007 | rand_drbg_lock(drbg); |
c16de9d8 DMSP |
1008 | ret = rand_drbg_restart(drbg, buf, |
1009 | (size_t)(unsigned int)num, | |
1010 | (size_t)(8*randomness)); | |
812b1537 | 1011 | rand_drbg_unlock(drbg); |
c16de9d8 DMSP |
1012 | |
1013 | return ret; | |
75e2c877 RS |
1014 | } |
1015 | ||
c16de9d8 | 1016 | /* Implements the default OpenSSL RAND_seed() method */ |
75e2c877 RS |
1017 | static int drbg_seed(const void *buf, int num) |
1018 | { | |
1019 | return drbg_add(buf, num, num); | |
1020 | } | |
1021 | ||
c16de9d8 | 1022 | /* Implements the default OpenSSL RAND_status() method */ |
75e2c877 | 1023 | static int drbg_status(void) |
12fb8c3d | 1024 | { |
75e2c877 | 1025 | int ret; |
a93ba405 | 1026 | RAND_DRBG *drbg = RAND_DRBG_get0_master(); |
0b14a5b7 KR |
1027 | |
1028 | if (drbg == NULL) | |
1029 | return 0; | |
75e2c877 | 1030 | |
812b1537 | 1031 | rand_drbg_lock(drbg); |
0b14a5b7 | 1032 | ret = drbg->state == DRBG_READY ? 1 : 0; |
812b1537 | 1033 | rand_drbg_unlock(drbg); |
75e2c877 | 1034 | return ret; |
12fb8c3d RS |
1035 | } |
1036 | ||
0b14a5b7 | 1037 | /* |
a93ba405 DMSP |
1038 | * Get the master DRBG. |
1039 | * Returns pointer to the DRBG on success, NULL on failure. | |
1040 | * | |
1041 | */ | |
1042 | RAND_DRBG *RAND_DRBG_get0_master(void) | |
1043 | { | |
1044 | if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) | |
1045 | return NULL; | |
1046 | ||
933033b6 | 1047 | return drbg_master; |
a93ba405 DMSP |
1048 | } |
1049 | ||
1050 | /* | |
1051 | * Get the public DRBG. | |
0b14a5b7 KR |
1052 | * Returns pointer to the DRBG on success, NULL on failure. |
1053 | */ | |
a93ba405 | 1054 | RAND_DRBG *RAND_DRBG_get0_public(void) |
0b14a5b7 | 1055 | { |
7caf122e KR |
1056 | RAND_DRBG *drbg; |
1057 | ||
c16de9d8 | 1058 | if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) |
0b14a5b7 KR |
1059 | return NULL; |
1060 | ||
7caf122e KR |
1061 | drbg = CRYPTO_THREAD_get_local(&public_drbg_thread_local_key); |
1062 | if (drbg == NULL) { | |
1063 | ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND); | |
1064 | drbg = drbg_setup(drbg_master); | |
1065 | CRYPTO_THREAD_set_local(&public_drbg_thread_local_key, drbg); | |
1066 | } | |
1067 | return drbg; | |
0b14a5b7 KR |
1068 | } |
1069 | ||
1070 | /* | |
a93ba405 | 1071 | * Get the private DRBG. |
0b14a5b7 KR |
1072 | * Returns pointer to the DRBG on success, NULL on failure. |
1073 | */ | |
a93ba405 | 1074 | RAND_DRBG *RAND_DRBG_get0_private(void) |
0b14a5b7 | 1075 | { |
7caf122e KR |
1076 | RAND_DRBG *drbg; |
1077 | ||
c16de9d8 | 1078 | if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) |
0b14a5b7 KR |
1079 | return NULL; |
1080 | ||
7caf122e KR |
1081 | drbg = CRYPTO_THREAD_get_local(&private_drbg_thread_local_key); |
1082 | if (drbg == NULL) { | |
1083 | ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND); | |
1084 | drbg = drbg_setup(drbg_master); | |
1085 | CRYPTO_THREAD_set_local(&private_drbg_thread_local_key, drbg); | |
1086 | } | |
1087 | return drbg; | |
0b14a5b7 KR |
1088 | } |
1089 | ||
75e2c877 RS |
1090 | RAND_METHOD rand_meth = { |
1091 | drbg_seed, | |
1092 | drbg_bytes, | |
ddc6a5c8 | 1093 | NULL, |
75e2c877 RS |
1094 | drbg_add, |
1095 | drbg_bytes, | |
1096 | drbg_status | |
1097 | }; | |
1098 | ||
1099 | RAND_METHOD *RAND_OpenSSL(void) | |
12fb8c3d | 1100 | { |
75e2c877 | 1101 | return &rand_meth; |
12fb8c3d | 1102 | } |