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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 | /* | |
a73d990e DMSP |
20 | * Support framework for NIST SP 800-90A DRBG |
21 | * | |
22 | * See manual page RAND_DRBG(7) for a general overview. | |
75e2c877 | 23 | * |
12fb8c3d RS |
24 | * The OpenSSL model is to have new and free functions, and that new |
25 | * does all initialization. That is not the NIST model, which has | |
26 | * instantiation and un-instantiate, and re-use within a new/free | |
27 | * lifecycle. (No doubt this comes from the desire to support hardware | |
28 | * DRBG, where allocation of resources on something like an HSM is | |
29 | * a much bigger deal than just re-setting an allocated resource.) | |
12fb8c3d RS |
30 | */ |
31 | ||
a93ba405 | 32 | /* |
a73d990e | 33 | * The three shared DRBG instances |
a93ba405 | 34 | * |
a73d990e DMSP |
35 | * There are three shared DRBG instances: <master>, <public>, and <private>. |
36 | */ | |
37 | ||
38 | /* | |
39 | * The <master> DRBG | |
a93ba405 DMSP |
40 | * |
41 | * Not used directly by the application, only for reseeding the two other | |
42 | * DRBGs. It reseeds itself by pulling either randomness from os entropy | |
a73d990e | 43 | * sources or by consuming randomness which was added by RAND_add(). |
a93ba405 | 44 | * |
a73d990e DMSP |
45 | * The <master> DRBG is a global instance which is accessed concurrently by |
46 | * all threads. The necessary locking is managed automatically by its child | |
47 | * DRBG instances during reseeding. | |
48 | */ | |
49 | static RAND_DRBG *master_drbg; | |
50 | /* | |
51 | * The <public> DRBG | |
a93ba405 | 52 | * |
a73d990e | 53 | * Used by default for generating random bytes using RAND_bytes(). |
3ce1c27b | 54 | * |
a73d990e DMSP |
55 | * The <public> DRBG is thread-local, i.e., there is one instance per thread. |
56 | */ | |
57 | static CRYPTO_THREAD_LOCAL public_drbg; | |
58 | /* | |
59 | * The <private> DRBG | |
3ce1c27b | 60 | * |
a73d990e | 61 | * Used by default for generating private keys using RAND_priv_bytes() |
812b1537 | 62 | * |
a73d990e | 63 | * The <private> DRBG is thread-local, i.e., there is one instance per thread. |
a93ba405 | 64 | */ |
a73d990e DMSP |
65 | static CRYPTO_THREAD_LOCAL private_drbg; |
66 | ||
a93ba405 DMSP |
67 | |
68 | ||
69 | /* NIST SP 800-90A DRBG recommends the use of a personalization string. */ | |
70 | static const char ossl_pers_string[] = "OpenSSL NIST SP 800-90A DRBG"; | |
71 | ||
c16de9d8 DMSP |
72 | static CRYPTO_ONCE rand_drbg_init = CRYPTO_ONCE_STATIC_INIT; |
73 | ||
31393fd9 DMSP |
74 | |
75 | ||
76 | static int rand_drbg_type = RAND_DRBG_TYPE; | |
77 | static unsigned int rand_drbg_flags = RAND_DRBG_FLAGS; | |
78 | ||
4917e911 DMSP |
79 | static unsigned int master_reseed_interval = MASTER_RESEED_INTERVAL; |
80 | static unsigned int slave_reseed_interval = SLAVE_RESEED_INTERVAL; | |
81 | ||
82 | static time_t master_reseed_time_interval = MASTER_RESEED_TIME_INTERVAL; | |
83 | static time_t slave_reseed_time_interval = SLAVE_RESEED_TIME_INTERVAL; | |
84 | ||
c402e943 DMSP |
85 | /* A logical OR of all used DRBG flag bits (currently there is only one) */ |
86 | static const unsigned int rand_drbg_used_flags = | |
87 | RAND_DRBG_FLAG_CTR_NO_DF; | |
88 | ||
63ab5ea1 | 89 | static RAND_DRBG *drbg_setup(RAND_DRBG *parent); |
4f9dabbf DMSP |
90 | |
91 | static RAND_DRBG *rand_drbg_new(int secure, | |
92 | int type, | |
93 | unsigned int flags, | |
94 | RAND_DRBG *parent); | |
0b14a5b7 | 95 | |
12fb8c3d | 96 | /* |
31393fd9 DMSP |
97 | * Set/initialize |drbg| to be of type |type|, with optional |flags|. |
98 | * | |
99 | * If |type| and |flags| are zero, use the defaults | |
efb8128a DMSP |
100 | * |
101 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 102 | */ |
31393fd9 | 103 | int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags) |
12fb8c3d RS |
104 | { |
105 | int ret = 1; | |
106 | ||
31393fd9 DMSP |
107 | if (type == 0 && flags == 0) { |
108 | type = rand_drbg_type; | |
109 | flags = rand_drbg_flags; | |
110 | } | |
111 | ||
75e2c877 RS |
112 | drbg->state = DRBG_UNINITIALISED; |
113 | drbg->flags = flags; | |
31393fd9 | 114 | drbg->type = type; |
12fb8c3d | 115 | |
31393fd9 | 116 | switch (type) { |
12fb8c3d RS |
117 | default: |
118 | RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE); | |
efb8128a | 119 | return 0; |
12fb8c3d RS |
120 | case 0: |
121 | /* Uninitialized; that's okay. */ | |
122 | return 1; | |
123 | case NID_aes_128_ctr: | |
124 | case NID_aes_192_ctr: | |
125 | case NID_aes_256_ctr: | |
8212d505 | 126 | ret = drbg_ctr_init(drbg); |
12fb8c3d RS |
127 | break; |
128 | } | |
129 | ||
efb8128a | 130 | if (ret == 0) |
12fb8c3d RS |
131 | RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG); |
132 | return ret; | |
133 | } | |
134 | ||
31393fd9 DMSP |
135 | /* |
136 | * Set/initialize default |type| and |flag| for new drbg instances. | |
137 | * | |
138 | * Returns 1 on success, 0 on failure. | |
139 | */ | |
140 | int RAND_DRBG_set_defaults(int type, unsigned int flags) | |
141 | { | |
142 | int ret = 1; | |
143 | ||
144 | switch (type) { | |
145 | default: | |
146 | RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_TYPE); | |
147 | return 0; | |
148 | case NID_aes_128_ctr: | |
149 | case NID_aes_192_ctr: | |
150 | case NID_aes_256_ctr: | |
151 | break; | |
152 | } | |
153 | ||
c402e943 | 154 | if ((flags & ~rand_drbg_used_flags) != 0) { |
31393fd9 DMSP |
155 | RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_FLAGS); |
156 | return 0; | |
157 | } | |
158 | ||
159 | rand_drbg_type = type; | |
160 | rand_drbg_flags = flags; | |
161 | ||
162 | return ret; | |
163 | } | |
164 | ||
165 | ||
12fb8c3d | 166 | /* |
4f9dabbf DMSP |
167 | * Allocate memory and initialize a new DRBG. The DRBG is allocated on |
168 | * the secure heap if |secure| is nonzero and the secure heap is enabled. | |
169 | * The |parent|, if not NULL, will be used as random source for reseeding. | |
a93ba405 DMSP |
170 | * |
171 | * Returns a pointer to the new DRBG instance on success, NULL on failure. | |
12fb8c3d | 172 | */ |
4f9dabbf DMSP |
173 | static RAND_DRBG *rand_drbg_new(int secure, |
174 | int type, | |
175 | unsigned int flags, | |
176 | RAND_DRBG *parent) | |
12fb8c3d | 177 | { |
4f9dabbf DMSP |
178 | RAND_DRBG *drbg = secure ? |
179 | OPENSSL_secure_zalloc(sizeof(*drbg)) : OPENSSL_zalloc(sizeof(*drbg)); | |
12fb8c3d | 180 | |
9d951a78 | 181 | if (drbg == NULL) { |
12fb8c3d | 182 | RANDerr(RAND_F_RAND_DRBG_NEW, ERR_R_MALLOC_FAILURE); |
f96ff4e9 | 183 | return NULL; |
12fb8c3d | 184 | } |
4f9dabbf DMSP |
185 | |
186 | drbg->secure = secure && CRYPTO_secure_allocated(drbg); | |
a35f607c | 187 | drbg->fork_count = rand_fork_count; |
75e2c877 | 188 | drbg->parent = parent; |
4917e911 DMSP |
189 | |
190 | if (parent == NULL) { | |
5bc6bcf8 DMSP |
191 | drbg->get_entropy = rand_drbg_get_entropy; |
192 | drbg->cleanup_entropy = rand_drbg_cleanup_entropy; | |
193 | #ifndef RAND_DRBG_GET_RANDOM_NONCE | |
194 | drbg->get_nonce = rand_drbg_get_nonce; | |
195 | drbg->cleanup_nonce = rand_drbg_cleanup_nonce; | |
196 | #endif | |
197 | ||
4917e911 DMSP |
198 | drbg->reseed_interval = master_reseed_interval; |
199 | drbg->reseed_time_interval = master_reseed_time_interval; | |
200 | } else { | |
5bc6bcf8 DMSP |
201 | drbg->get_entropy = rand_drbg_get_entropy; |
202 | drbg->cleanup_entropy = rand_drbg_cleanup_entropy; | |
203 | /* | |
204 | * Do not provide nonce callbacks, the child DRBGs will | |
205 | * obtain their nonce using random bits from the parent. | |
206 | */ | |
207 | ||
4917e911 DMSP |
208 | drbg->reseed_interval = slave_reseed_interval; |
209 | drbg->reseed_time_interval = slave_reseed_time_interval; | |
210 | } | |
211 | ||
efb8128a | 212 | if (RAND_DRBG_set(drbg, type, flags) == 0) |
75e2c877 RS |
213 | goto err; |
214 | ||
7caf122e KR |
215 | if (parent != NULL) { |
216 | rand_drbg_lock(parent); | |
217 | if (drbg->strength > parent->strength) { | |
218 | /* | |
219 | * We currently don't support the algorithm from NIST SP 800-90C | |
220 | * 10.1.2 to use a weaker DRBG as source | |
221 | */ | |
222 | rand_drbg_unlock(parent); | |
223 | RANDerr(RAND_F_RAND_DRBG_NEW, RAND_R_PARENT_STRENGTH_TOO_WEAK); | |
224 | goto err; | |
225 | } | |
226 | rand_drbg_unlock(parent); | |
35503b7c KR |
227 | } |
228 | ||
75e2c877 RS |
229 | return drbg; |
230 | ||
231 | err: | |
4f9dabbf DMSP |
232 | if (drbg->secure) |
233 | OPENSSL_secure_free(drbg); | |
234 | else | |
235 | OPENSSL_free(drbg); | |
236 | ||
75e2c877 | 237 | return NULL; |
12fb8c3d RS |
238 | } |
239 | ||
4f9dabbf DMSP |
240 | RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent) |
241 | { | |
242 | return rand_drbg_new(0, type, flags, parent); | |
243 | } | |
244 | ||
245 | RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent) | |
246 | { | |
247 | return rand_drbg_new(1, type, flags, parent); | |
248 | } | |
249 | ||
12fb8c3d | 250 | /* |
75e2c877 | 251 | * Uninstantiate |drbg| and free all memory. |
12fb8c3d | 252 | */ |
75e2c877 | 253 | void RAND_DRBG_free(RAND_DRBG *drbg) |
12fb8c3d | 254 | { |
c16de9d8 | 255 | if (drbg == NULL) |
12fb8c3d RS |
256 | return; |
257 | ||
8212d505 DMSP |
258 | if (drbg->meth != NULL) |
259 | drbg->meth->uninstantiate(drbg); | |
4f9dabbf | 260 | CRYPTO_THREAD_lock_free(drbg->lock); |
75e2c877 | 261 | CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data); |
4f9dabbf DMSP |
262 | |
263 | if (drbg->secure) | |
264 | OPENSSL_secure_clear_free(drbg, sizeof(*drbg)); | |
265 | else | |
266 | OPENSSL_clear_free(drbg, sizeof(*drbg)); | |
12fb8c3d RS |
267 | } |
268 | ||
269 | /* | |
75e2c877 | 270 | * Instantiate |drbg|, after it has been initialized. Use |pers| and |
12fb8c3d | 271 | * |perslen| as prediction-resistance input. |
2139145b BK |
272 | * |
273 | * Requires that drbg->lock is already locked for write, if non-null. | |
efb8128a DMSP |
274 | * |
275 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 276 | */ |
75e2c877 | 277 | int RAND_DRBG_instantiate(RAND_DRBG *drbg, |
12fb8c3d RS |
278 | const unsigned char *pers, size_t perslen) |
279 | { | |
12fb8c3d | 280 | unsigned char *nonce = NULL, *entropy = NULL; |
aa048aef | 281 | size_t noncelen = 0, entropylen = 0; |
2a70d65b KR |
282 | size_t min_entropy = drbg->strength; |
283 | size_t min_entropylen = drbg->min_entropylen; | |
284 | size_t max_entropylen = drbg->max_entropylen; | |
12fb8c3d | 285 | |
aa048aef | 286 | if (perslen > drbg->max_perslen) { |
75e2c877 RS |
287 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, |
288 | RAND_R_PERSONALISATION_STRING_TOO_LONG); | |
12fb8c3d RS |
289 | goto end; |
290 | } | |
8212d505 | 291 | |
272c0df8 | 292 | if (drbg->meth == NULL) { |
8212d505 DMSP |
293 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, |
294 | RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED); | |
295 | goto end; | |
296 | } | |
297 | ||
75e2c877 RS |
298 | if (drbg->state != DRBG_UNINITIALISED) { |
299 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, | |
300 | drbg->state == DRBG_ERROR ? RAND_R_IN_ERROR_STATE | |
301 | : RAND_R_ALREADY_INSTANTIATED); | |
12fb8c3d RS |
302 | goto end; |
303 | } | |
304 | ||
75e2c877 | 305 | drbg->state = DRBG_ERROR; |
2a70d65b KR |
306 | |
307 | /* | |
308 | * NIST SP800-90Ar1 section 9.1 says you can combine getting the entropy | |
309 | * and nonce in 1 call by increasing the entropy with 50% and increasing | |
310 | * the minimum length to accomadate the length of the nonce. | |
311 | * We do this in case a nonce is require and get_nonce is NULL. | |
312 | */ | |
313 | if (drbg->min_noncelen > 0 && drbg->get_nonce == NULL) { | |
314 | min_entropy += drbg->strength / 2; | |
315 | min_entropylen += drbg->min_noncelen; | |
316 | max_entropylen += drbg->max_noncelen; | |
317 | } | |
318 | ||
75e2c877 | 319 | if (drbg->get_entropy != NULL) |
2a70d65b KR |
320 | entropylen = drbg->get_entropy(drbg, &entropy, min_entropy, |
321 | min_entropylen, max_entropylen, 0); | |
322 | if (entropylen < min_entropylen | |
323 | || entropylen > max_entropylen) { | |
75e2c877 | 324 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_ENTROPY); |
12fb8c3d RS |
325 | goto end; |
326 | } | |
327 | ||
2a70d65b | 328 | if (drbg->min_noncelen > 0 && drbg->get_nonce != NULL) { |
75e2c877 | 329 | noncelen = drbg->get_nonce(drbg, &nonce, drbg->strength / 2, |
aa048aef DMSP |
330 | drbg->min_noncelen, drbg->max_noncelen); |
331 | if (noncelen < drbg->min_noncelen || noncelen > drbg->max_noncelen) { | |
2a70d65b | 332 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_NONCE); |
12fb8c3d RS |
333 | goto end; |
334 | } | |
335 | } | |
336 | ||
8212d505 | 337 | if (!drbg->meth->instantiate(drbg, entropy, entropylen, |
12fb8c3d | 338 | nonce, noncelen, pers, perslen)) { |
75e2c877 | 339 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_INSTANTIATING_DRBG); |
12fb8c3d RS |
340 | goto end; |
341 | } | |
342 | ||
75e2c877 | 343 | drbg->state = DRBG_READY; |
a93ba405 | 344 | drbg->generate_counter = 0; |
08a65d96 | 345 | drbg->reseed_time = time(NULL); |
a93ba405 DMSP |
346 | if (drbg->reseed_counter > 0) { |
347 | if (drbg->parent == NULL) | |
348 | drbg->reseed_counter++; | |
349 | else | |
350 | drbg->reseed_counter = drbg->parent->reseed_counter; | |
351 | } | |
12fb8c3d RS |
352 | |
353 | end: | |
75e2c877 | 354 | if (entropy != NULL && drbg->cleanup_entropy != NULL) |
6969a3f4 | 355 | drbg->cleanup_entropy(drbg, entropy, entropylen); |
75e2c877 | 356 | if (nonce != NULL && drbg->cleanup_nonce!= NULL ) |
6969a3f4 | 357 | drbg->cleanup_nonce(drbg, nonce, noncelen); |
c16de9d8 DMSP |
358 | if (drbg->pool != NULL) { |
359 | if (drbg->state == DRBG_READY) { | |
360 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, | |
361 | RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED); | |
362 | drbg->state = DRBG_ERROR; | |
363 | } | |
6decf943 | 364 | rand_pool_free(drbg->pool); |
c16de9d8 DMSP |
365 | drbg->pool = NULL; |
366 | } | |
75e2c877 | 367 | if (drbg->state == DRBG_READY) |
12fb8c3d | 368 | return 1; |
12fb8c3d RS |
369 | return 0; |
370 | } | |
371 | ||
372 | /* | |
75e2c877 | 373 | * Uninstantiate |drbg|. Must be instantiated before it can be used. |
2139145b BK |
374 | * |
375 | * Requires that drbg->lock is already locked for write, if non-null. | |
efb8128a DMSP |
376 | * |
377 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 378 | */ |
75e2c877 | 379 | int RAND_DRBG_uninstantiate(RAND_DRBG *drbg) |
12fb8c3d | 380 | { |
272c0df8 | 381 | if (drbg->meth == NULL) { |
8212d505 DMSP |
382 | RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE, |
383 | RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED); | |
384 | return 0; | |
385 | } | |
386 | ||
efb8128a DMSP |
387 | /* Clear the entire drbg->ctr struct, then reset some important |
388 | * members of the drbg->ctr struct (e.g. keysize, df_ks) to their | |
389 | * initial values. | |
390 | */ | |
8212d505 | 391 | drbg->meth->uninstantiate(drbg); |
31393fd9 | 392 | return RAND_DRBG_set(drbg, drbg->type, drbg->flags); |
12fb8c3d RS |
393 | } |
394 | ||
395 | /* | |
c16de9d8 | 396 | * Reseed |drbg|, mixing in the specified data |
2139145b BK |
397 | * |
398 | * Requires that drbg->lock is already locked for write, if non-null. | |
efb8128a DMSP |
399 | * |
400 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 401 | */ |
75e2c877 | 402 | int RAND_DRBG_reseed(RAND_DRBG *drbg, |
eb238134 KR |
403 | const unsigned char *adin, size_t adinlen, |
404 | int prediction_resistance) | |
12fb8c3d RS |
405 | { |
406 | unsigned char *entropy = NULL; | |
aa048aef | 407 | size_t entropylen = 0; |
75e2c877 RS |
408 | |
409 | if (drbg->state == DRBG_ERROR) { | |
410 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_IN_ERROR_STATE); | |
411 | return 0; | |
412 | } | |
413 | if (drbg->state == DRBG_UNINITIALISED) { | |
414 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_NOT_INSTANTIATED); | |
415 | return 0; | |
12fb8c3d RS |
416 | } |
417 | ||
272c0df8 | 418 | if (adin == NULL) { |
12fb8c3d | 419 | adinlen = 0; |
272c0df8 | 420 | } else if (adinlen > drbg->max_adinlen) { |
75e2c877 RS |
421 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ADDITIONAL_INPUT_TOO_LONG); |
422 | return 0; | |
12fb8c3d RS |
423 | } |
424 | ||
75e2c877 RS |
425 | drbg->state = DRBG_ERROR; |
426 | if (drbg->get_entropy != NULL) | |
aa048aef | 427 | entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength, |
eb238134 KR |
428 | drbg->min_entropylen, |
429 | drbg->max_entropylen, | |
430 | prediction_resistance); | |
c16de9d8 DMSP |
431 | if (entropylen < drbg->min_entropylen |
432 | || entropylen > drbg->max_entropylen) { | |
75e2c877 | 433 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ERROR_RETRIEVING_ENTROPY); |
12fb8c3d RS |
434 | goto end; |
435 | } | |
436 | ||
8212d505 | 437 | if (!drbg->meth->reseed(drbg, entropy, entropylen, adin, adinlen)) |
12fb8c3d | 438 | goto end; |
a93ba405 | 439 | |
75e2c877 | 440 | drbg->state = DRBG_READY; |
a93ba405 | 441 | drbg->generate_counter = 0; |
08a65d96 | 442 | drbg->reseed_time = time(NULL); |
a93ba405 DMSP |
443 | if (drbg->reseed_counter > 0) { |
444 | if (drbg->parent == NULL) | |
445 | drbg->reseed_counter++; | |
446 | else | |
447 | drbg->reseed_counter = drbg->parent->reseed_counter; | |
448 | } | |
12fb8c3d RS |
449 | |
450 | end: | |
75e2c877 | 451 | if (entropy != NULL && drbg->cleanup_entropy != NULL) |
6969a3f4 | 452 | drbg->cleanup_entropy(drbg, entropy, entropylen); |
75e2c877 | 453 | if (drbg->state == DRBG_READY) |
12fb8c3d | 454 | return 1; |
12fb8c3d RS |
455 | return 0; |
456 | } | |
457 | ||
c16de9d8 DMSP |
458 | /* |
459 | * Restart |drbg|, using the specified entropy or additional input | |
460 | * | |
461 | * Tries its best to get the drbg instantiated by all means, | |
462 | * regardless of its current state. | |
463 | * | |
464 | * Optionally, a |buffer| of |len| random bytes can be passed, | |
465 | * which is assumed to contain at least |entropy| bits of entropy. | |
466 | * | |
467 | * If |entropy| > 0, the buffer content is used as entropy input. | |
468 | * | |
469 | * If |entropy| == 0, the buffer content is used as additional input | |
470 | * | |
471 | * Returns 1 on success, 0 on failure. | |
472 | * | |
473 | * This function is used internally only. | |
474 | */ | |
475 | int rand_drbg_restart(RAND_DRBG *drbg, | |
476 | const unsigned char *buffer, size_t len, size_t entropy) | |
477 | { | |
478 | int reseeded = 0; | |
479 | const unsigned char *adin = NULL; | |
480 | size_t adinlen = 0; | |
481 | ||
482 | if (drbg->pool != NULL) { | |
483 | RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR); | |
6decf943 | 484 | rand_pool_free(drbg->pool); |
c16de9d8 DMSP |
485 | drbg->pool = NULL; |
486 | } | |
487 | ||
488 | if (buffer != NULL) { | |
489 | if (entropy > 0) { | |
490 | if (drbg->max_entropylen < len) { | |
491 | RANDerr(RAND_F_RAND_DRBG_RESTART, | |
492 | RAND_R_ENTROPY_INPUT_TOO_LONG); | |
493 | return 0; | |
494 | } | |
495 | ||
496 | if (entropy > 8 * len) { | |
497 | RANDerr(RAND_F_RAND_DRBG_RESTART, RAND_R_ENTROPY_OUT_OF_RANGE); | |
498 | return 0; | |
499 | } | |
500 | ||
501 | /* will be picked up by the rand_drbg_get_entropy() callback */ | |
6decf943 | 502 | drbg->pool = rand_pool_new(entropy, len, len); |
c16de9d8 DMSP |
503 | if (drbg->pool == NULL) |
504 | return 0; | |
505 | ||
6decf943 | 506 | rand_pool_add(drbg->pool, buffer, len, entropy); |
c16de9d8 DMSP |
507 | } else { |
508 | if (drbg->max_adinlen < len) { | |
509 | RANDerr(RAND_F_RAND_DRBG_RESTART, | |
510 | RAND_R_ADDITIONAL_INPUT_TOO_LONG); | |
511 | return 0; | |
512 | } | |
513 | adin = buffer; | |
514 | adinlen = len; | |
515 | } | |
516 | } | |
517 | ||
518 | /* repair error state */ | |
efb8128a | 519 | if (drbg->state == DRBG_ERROR) |
c16de9d8 DMSP |
520 | RAND_DRBG_uninstantiate(drbg); |
521 | ||
522 | /* repair uninitialized state */ | |
523 | if (drbg->state == DRBG_UNINITIALISED) { | |
a93ba405 DMSP |
524 | /* reinstantiate drbg */ |
525 | RAND_DRBG_instantiate(drbg, | |
526 | (const unsigned char *) ossl_pers_string, | |
527 | sizeof(ossl_pers_string) - 1); | |
c16de9d8 DMSP |
528 | /* already reseeded. prevent second reseeding below */ |
529 | reseeded = (drbg->state == DRBG_READY); | |
530 | } | |
531 | ||
532 | /* refresh current state if entropy or additional input has been provided */ | |
533 | if (drbg->state == DRBG_READY) { | |
534 | if (adin != NULL) { | |
535 | /* | |
536 | * mix in additional input without reseeding | |
537 | * | |
538 | * Similar to RAND_DRBG_reseed(), but the provided additional | |
539 | * data |adin| is mixed into the current state without pulling | |
540 | * entropy from the trusted entropy source using get_entropy(). | |
541 | * This is not a reseeding in the strict sense of NIST SP 800-90A. | |
542 | */ | |
8212d505 | 543 | drbg->meth->reseed(drbg, adin, adinlen, NULL, 0); |
c16de9d8 DMSP |
544 | } else if (reseeded == 0) { |
545 | /* do a full reseeding if it has not been done yet above */ | |
eb238134 | 546 | RAND_DRBG_reseed(drbg, NULL, 0, 0); |
c16de9d8 DMSP |
547 | } |
548 | } | |
549 | ||
550 | /* check whether a given entropy pool was cleared properly during reseed */ | |
551 | if (drbg->pool != NULL) { | |
552 | drbg->state = DRBG_ERROR; | |
553 | RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR); | |
6decf943 | 554 | rand_pool_free(drbg->pool); |
c16de9d8 DMSP |
555 | drbg->pool = NULL; |
556 | return 0; | |
557 | } | |
558 | ||
559 | return drbg->state == DRBG_READY; | |
560 | } | |
561 | ||
12fb8c3d RS |
562 | /* |
563 | * Generate |outlen| bytes into the buffer at |out|. Reseed if we need | |
564 | * to or if |prediction_resistance| is set. Additional input can be | |
565 | * sent in |adin| and |adinlen|. | |
c16de9d8 | 566 | * |
2139145b BK |
567 | * Requires that drbg->lock is already locked for write, if non-null. |
568 | * | |
c16de9d8 DMSP |
569 | * Returns 1 on success, 0 on failure. |
570 | * | |
12fb8c3d | 571 | */ |
75e2c877 | 572 | int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen, |
12fb8c3d RS |
573 | int prediction_resistance, |
574 | const unsigned char *adin, size_t adinlen) | |
575 | { | |
e0b625f9 DMSP |
576 | int reseed_required = 0; |
577 | ||
c16de9d8 DMSP |
578 | if (drbg->state != DRBG_READY) { |
579 | /* try to recover from previous errors */ | |
580 | rand_drbg_restart(drbg, NULL, 0, 0); | |
581 | ||
582 | if (drbg->state == DRBG_ERROR) { | |
583 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_IN_ERROR_STATE); | |
584 | return 0; | |
585 | } | |
586 | if (drbg->state == DRBG_UNINITIALISED) { | |
587 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_NOT_INSTANTIATED); | |
588 | return 0; | |
589 | } | |
12fb8c3d | 590 | } |
c16de9d8 | 591 | |
75e2c877 RS |
592 | if (outlen > drbg->max_request) { |
593 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG); | |
594 | return 0; | |
595 | } | |
aa048aef | 596 | if (adinlen > drbg->max_adinlen) { |
75e2c877 RS |
597 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_ADDITIONAL_INPUT_TOO_LONG); |
598 | return 0; | |
12fb8c3d RS |
599 | } |
600 | ||
a35f607c RS |
601 | if (drbg->fork_count != rand_fork_count) { |
602 | drbg->fork_count = rand_fork_count; | |
e0b625f9 | 603 | reseed_required = 1; |
a35f607c RS |
604 | } |
605 | ||
a93ba405 DMSP |
606 | if (drbg->reseed_interval > 0) { |
607 | if (drbg->generate_counter >= drbg->reseed_interval) | |
608 | reseed_required = 1; | |
609 | } | |
08a65d96 DMSP |
610 | if (drbg->reseed_time_interval > 0) { |
611 | time_t now = time(NULL); | |
612 | if (now < drbg->reseed_time | |
613 | || now - drbg->reseed_time >= drbg->reseed_time_interval) | |
614 | reseed_required = 1; | |
615 | } | |
a93ba405 DMSP |
616 | if (drbg->reseed_counter > 0 && drbg->parent != NULL) { |
617 | if (drbg->reseed_counter != drbg->parent->reseed_counter) | |
618 | reseed_required = 1; | |
619 | } | |
12fb8c3d | 620 | |
e0b625f9 | 621 | if (reseed_required || prediction_resistance) { |
eb238134 | 622 | if (!RAND_DRBG_reseed(drbg, adin, adinlen, prediction_resistance)) { |
75e2c877 RS |
623 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_RESEED_ERROR); |
624 | return 0; | |
12fb8c3d RS |
625 | } |
626 | adin = NULL; | |
627 | adinlen = 0; | |
628 | } | |
629 | ||
8212d505 | 630 | if (!drbg->meth->generate(drbg, out, outlen, adin, adinlen)) { |
75e2c877 RS |
631 | drbg->state = DRBG_ERROR; |
632 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_GENERATE_ERROR); | |
633 | return 0; | |
12fb8c3d | 634 | } |
75e2c877 | 635 | |
a93ba405 | 636 | drbg->generate_counter++; |
e0b625f9 | 637 | |
12fb8c3d | 638 | return 1; |
12fb8c3d RS |
639 | } |
640 | ||
20928ff6 KR |
641 | /* |
642 | * Generates |outlen| random bytes and stores them in |out|. It will | |
643 | * using the given |drbg| to generate the bytes. | |
644 | * | |
645 | * Requires that drbg->lock is already locked for write, if non-null. | |
646 | * | |
647 | * Returns 1 on success 0 on failure. | |
648 | */ | |
649 | int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen) | |
650 | { | |
651 | unsigned char *additional = NULL; | |
652 | size_t additional_len; | |
1648338b | 653 | size_t chunk; |
20928ff6 KR |
654 | size_t ret; |
655 | ||
656 | additional_len = rand_drbg_get_additional_data(&additional, drbg->max_adinlen); | |
1648338b DMSP |
657 | |
658 | for ( ; outlen > 0; outlen -= chunk, out += chunk) { | |
659 | chunk = outlen; | |
660 | if (chunk > drbg->max_request) | |
661 | chunk = drbg->max_request; | |
662 | ret = RAND_DRBG_generate(drbg, out, chunk, 0, additional, additional_len); | |
663 | if (!ret) | |
664 | goto err; | |
665 | } | |
666 | ret = 1; | |
667 | ||
668 | err: | |
20928ff6 KR |
669 | if (additional_len != 0) |
670 | OPENSSL_secure_clear_free(additional, additional_len); | |
671 | ||
672 | return ret; | |
673 | } | |
674 | ||
12fb8c3d | 675 | /* |
c16de9d8 DMSP |
676 | * Set the RAND_DRBG callbacks for obtaining entropy and nonce. |
677 | * | |
a73d990e DMSP |
678 | * Setting the callbacks is allowed only if the drbg has not been |
679 | * initialized yet. Otherwise, the operation will fail. | |
c16de9d8 | 680 | * |
a73d990e | 681 | * Returns 1 on success, 0 on failure. |
12fb8c3d | 682 | */ |
75e2c877 | 683 | int RAND_DRBG_set_callbacks(RAND_DRBG *drbg, |
c16de9d8 DMSP |
684 | RAND_DRBG_get_entropy_fn get_entropy, |
685 | RAND_DRBG_cleanup_entropy_fn cleanup_entropy, | |
686 | RAND_DRBG_get_nonce_fn get_nonce, | |
687 | RAND_DRBG_cleanup_nonce_fn cleanup_nonce) | |
12fb8c3d | 688 | { |
75e2c877 | 689 | if (drbg->state != DRBG_UNINITIALISED) |
12fb8c3d | 690 | return 0; |
c16de9d8 DMSP |
691 | drbg->get_entropy = get_entropy; |
692 | drbg->cleanup_entropy = cleanup_entropy; | |
693 | drbg->get_nonce = get_nonce; | |
694 | drbg->cleanup_nonce = cleanup_nonce; | |
12fb8c3d RS |
695 | return 1; |
696 | } | |
697 | ||
698 | /* | |
75e2c877 | 699 | * Set the reseed interval. |
a93ba405 DMSP |
700 | * |
701 | * The drbg will reseed automatically whenever the number of generate | |
702 | * requests exceeds the given reseed interval. If the reseed interval | |
08a65d96 | 703 | * is 0, then this feature is disabled. |
a93ba405 DMSP |
704 | * |
705 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 706 | */ |
a93ba405 | 707 | int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval) |
12fb8c3d | 708 | { |
a93ba405 | 709 | if (interval > MAX_RESEED_INTERVAL) |
4c75ee85 | 710 | return 0; |
75e2c877 | 711 | drbg->reseed_interval = interval; |
4c75ee85 | 712 | return 1; |
12fb8c3d RS |
713 | } |
714 | ||
08a65d96 DMSP |
715 | /* |
716 | * Set the reseed time interval. | |
717 | * | |
718 | * The drbg will reseed automatically whenever the time elapsed since | |
719 | * the last reseeding exceeds the given reseed time interval. For safety, | |
720 | * a reseeding will also occur if the clock has been reset to a smaller | |
721 | * value. | |
722 | * | |
723 | * Returns 1 on success, 0 on failure. | |
724 | */ | |
725 | int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval) | |
726 | { | |
727 | if (interval > MAX_RESEED_TIME_INTERVAL) | |
728 | return 0; | |
729 | drbg->reseed_time_interval = interval; | |
730 | return 1; | |
731 | } | |
732 | ||
4917e911 DMSP |
733 | /* |
734 | * Set the default values for reseed (time) intervals of new DRBG instances | |
735 | * | |
736 | * The default values can be set independently for master DRBG instances | |
737 | * (without a parent) and slave DRBG instances (with parent). | |
738 | * | |
739 | * Returns 1 on success, 0 on failure. | |
740 | */ | |
741 | ||
742 | int RAND_DRBG_set_reseed_defaults( | |
743 | unsigned int _master_reseed_interval, | |
744 | unsigned int _slave_reseed_interval, | |
745 | time_t _master_reseed_time_interval, | |
746 | time_t _slave_reseed_time_interval | |
747 | ) | |
748 | { | |
749 | if (_master_reseed_interval > MAX_RESEED_INTERVAL | |
750 | || _slave_reseed_interval > MAX_RESEED_INTERVAL) | |
751 | return 0; | |
752 | ||
753 | if (_master_reseed_time_interval > MAX_RESEED_TIME_INTERVAL | |
754 | || _slave_reseed_time_interval > MAX_RESEED_TIME_INTERVAL) | |
755 | return 0; | |
756 | ||
757 | master_reseed_interval = _master_reseed_interval; | |
758 | slave_reseed_interval = _slave_reseed_interval; | |
759 | ||
760 | master_reseed_time_interval = _master_reseed_time_interval; | |
761 | slave_reseed_time_interval = _slave_reseed_time_interval; | |
762 | ||
763 | return 1; | |
764 | } | |
3ce1c27b DMSP |
765 | |
766 | /* | |
767 | * Locks the given drbg. Locking a drbg which does not have locking | |
768 | * enabled is considered a successful no-op. | |
769 | * | |
770 | * Returns 1 on success, 0 on failure. | |
771 | */ | |
812b1537 | 772 | int rand_drbg_lock(RAND_DRBG *drbg) |
3ce1c27b DMSP |
773 | { |
774 | if (drbg->lock != NULL) | |
775 | return CRYPTO_THREAD_write_lock(drbg->lock); | |
776 | ||
777 | return 1; | |
778 | } | |
779 | ||
780 | /* | |
781 | * Unlocks the given drbg. Unlocking a drbg which does not have locking | |
782 | * enabled is considered a successful no-op. | |
783 | * | |
784 | * Returns 1 on success, 0 on failure. | |
785 | */ | |
812b1537 | 786 | int rand_drbg_unlock(RAND_DRBG *drbg) |
3ce1c27b DMSP |
787 | { |
788 | if (drbg->lock != NULL) | |
789 | return CRYPTO_THREAD_unlock(drbg->lock); | |
790 | ||
791 | return 1; | |
792 | } | |
793 | ||
794 | /* | |
795 | * Enables locking for the given drbg | |
796 | * | |
797 | * Locking can only be enabled if the random generator | |
798 | * is in the uninitialized state. | |
799 | * | |
800 | * Returns 1 on success, 0 on failure. | |
801 | */ | |
812b1537 | 802 | int rand_drbg_enable_locking(RAND_DRBG *drbg) |
3ce1c27b DMSP |
803 | { |
804 | if (drbg->state != DRBG_UNINITIALISED) { | |
805 | RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, | |
806 | RAND_R_DRBG_ALREADY_INITIALIZED); | |
807 | return 0; | |
808 | } | |
809 | ||
810 | if (drbg->lock == NULL) { | |
4f9dabbf | 811 | if (drbg->parent != NULL && drbg->parent->lock == NULL) { |
3ce1c27b DMSP |
812 | RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, |
813 | RAND_R_PARENT_LOCKING_NOT_ENABLED); | |
814 | return 0; | |
815 | } | |
816 | ||
817 | drbg->lock = CRYPTO_THREAD_lock_new(); | |
818 | if (drbg->lock == NULL) { | |
819 | RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, | |
820 | RAND_R_FAILED_TO_CREATE_LOCK); | |
821 | return 0; | |
822 | } | |
823 | } | |
824 | ||
825 | return 1; | |
826 | } | |
827 | ||
12fb8c3d RS |
828 | /* |
829 | * Get and set the EXDATA | |
830 | */ | |
75e2c877 RS |
831 | int RAND_DRBG_set_ex_data(RAND_DRBG *drbg, int idx, void *arg) |
832 | { | |
833 | return CRYPTO_set_ex_data(&drbg->ex_data, idx, arg); | |
834 | } | |
835 | ||
836 | void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx) | |
837 | { | |
838 | return CRYPTO_get_ex_data(&drbg->ex_data, idx); | |
839 | } | |
840 | ||
841 | ||
842 | /* | |
843 | * The following functions provide a RAND_METHOD that works on the | |
844 | * global DRBG. They lock. | |
845 | */ | |
846 | ||
0b14a5b7 | 847 | /* |
933033b6 DMSP |
848 | * Allocates a new global DRBG on the secure heap (if enabled) and |
849 | * initializes it with default settings. | |
a93ba405 DMSP |
850 | * |
851 | * Returns a pointer to the new DRBG instance on success, NULL on failure. | |
0b14a5b7 | 852 | */ |
63ab5ea1 | 853 | static RAND_DRBG *drbg_setup(RAND_DRBG *parent) |
0b14a5b7 | 854 | { |
933033b6 | 855 | RAND_DRBG *drbg; |
0b14a5b7 | 856 | |
31393fd9 | 857 | drbg = RAND_DRBG_secure_new(rand_drbg_type, rand_drbg_flags, parent); |
933033b6 DMSP |
858 | if (drbg == NULL) |
859 | return NULL; | |
860 | ||
7caf122e KR |
861 | /* Only the master DRBG needs to have a lock */ |
862 | if (parent == NULL && rand_drbg_enable_locking(drbg) == 0) | |
933033b6 | 863 | goto err; |
a93ba405 | 864 | |
a93ba405 DMSP |
865 | /* enable seed propagation */ |
866 | drbg->reseed_counter = 1; | |
867 | ||
c16de9d8 | 868 | /* |
43687d68 | 869 | * Ignore instantiation error to support just-in-time instantiation. |
c16de9d8 DMSP |
870 | * |
871 | * The state of the drbg will be checked in RAND_DRBG_generate() and | |
872 | * an automatic recovery is attempted. | |
873 | */ | |
43687d68 DMSP |
874 | (void)RAND_DRBG_instantiate(drbg, |
875 | (const unsigned char *) ossl_pers_string, | |
876 | sizeof(ossl_pers_string) - 1); | |
933033b6 DMSP |
877 | return drbg; |
878 | ||
879 | err: | |
4f9dabbf | 880 | RAND_DRBG_free(drbg); |
933033b6 | 881 | return NULL; |
0b14a5b7 KR |
882 | } |
883 | ||
884 | /* | |
885 | * Initialize the global DRBGs on first use. | |
886 | * Returns 1 on success, 0 on failure. | |
887 | */ | |
c16de9d8 | 888 | DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init) |
0b14a5b7 | 889 | { |
39571fca DMSP |
890 | /* |
891 | * ensure that libcrypto is initialized, otherwise the | |
892 | * DRBG locks are not cleaned up properly | |
893 | */ | |
894 | if (!OPENSSL_init_crypto(0, NULL)) | |
895 | return 0; | |
896 | ||
272c0df8 BE |
897 | if (!CRYPTO_THREAD_init_local(&private_drbg, NULL)) |
898 | return 0; | |
0b14a5b7 | 899 | |
272c0df8 BE |
900 | if (!CRYPTO_THREAD_init_local(&public_drbg, NULL)) |
901 | goto err1; | |
7caf122e | 902 | |
272c0df8 BE |
903 | master_drbg = drbg_setup(NULL); |
904 | if (master_drbg == NULL) | |
905 | goto err2; | |
0b14a5b7 | 906 | |
933033b6 | 907 | return 1; |
272c0df8 BE |
908 | |
909 | err2: | |
910 | CRYPTO_THREAD_cleanup_local(&public_drbg); | |
911 | err1: | |
912 | CRYPTO_THREAD_cleanup_local(&private_drbg); | |
913 | return 0; | |
0b14a5b7 KR |
914 | } |
915 | ||
0b14a5b7 | 916 | /* Clean up the global DRBGs before exit */ |
c16de9d8 | 917 | void rand_drbg_cleanup_int(void) |
0b14a5b7 | 918 | { |
bf7ae750 BE |
919 | if (master_drbg != NULL) { |
920 | RAND_DRBG_free(master_drbg); | |
921 | master_drbg = NULL; | |
933033b6 | 922 | |
bf7ae750 BE |
923 | CRYPTO_THREAD_cleanup_local(&private_drbg); |
924 | CRYPTO_THREAD_cleanup_local(&public_drbg); | |
925 | } | |
7caf122e KR |
926 | } |
927 | ||
3cb7c5cf | 928 | void drbg_delete_thread_state(void) |
7caf122e KR |
929 | { |
930 | RAND_DRBG *drbg; | |
931 | ||
a73d990e | 932 | drbg = CRYPTO_THREAD_get_local(&public_drbg); |
272c0df8 | 933 | CRYPTO_THREAD_set_local(&public_drbg, NULL); |
7caf122e KR |
934 | RAND_DRBG_free(drbg); |
935 | ||
a73d990e | 936 | drbg = CRYPTO_THREAD_get_local(&private_drbg); |
272c0df8 | 937 | CRYPTO_THREAD_set_local(&private_drbg, NULL); |
7caf122e | 938 | RAND_DRBG_free(drbg); |
0b14a5b7 KR |
939 | } |
940 | ||
c16de9d8 | 941 | /* Implements the default OpenSSL RAND_bytes() method */ |
75e2c877 RS |
942 | static int drbg_bytes(unsigned char *out, int count) |
943 | { | |
f61f62ea | 944 | int ret; |
a93ba405 | 945 | RAND_DRBG *drbg = RAND_DRBG_get0_public(); |
75e2c877 | 946 | |
0b14a5b7 KR |
947 | if (drbg == NULL) |
948 | return 0; | |
949 | ||
f61f62ea | 950 | ret = RAND_DRBG_bytes(drbg, out, count); |
f61f62ea | 951 | |
75e2c877 RS |
952 | return ret; |
953 | } | |
954 | ||
c16de9d8 | 955 | /* Implements the default OpenSSL RAND_add() method */ |
75e2c877 RS |
956 | static int drbg_add(const void *buf, int num, double randomness) |
957 | { | |
c16de9d8 | 958 | int ret = 0; |
a93ba405 | 959 | RAND_DRBG *drbg = RAND_DRBG_get0_master(); |
75e2c877 | 960 | |
c16de9d8 DMSP |
961 | if (drbg == NULL) |
962 | return 0; | |
75e2c877 | 963 | |
c16de9d8 DMSP |
964 | if (num < 0 || randomness < 0.0) |
965 | return 0; | |
75e2c877 | 966 | |
c16de9d8 DMSP |
967 | if (randomness > (double)drbg->max_entropylen) { |
968 | /* | |
969 | * The purpose of this check is to bound |randomness| by a | |
970 | * relatively small value in order to prevent an integer | |
971 | * overflow when multiplying by 8 in the rand_drbg_restart() | |
972 | * call below. | |
973 | */ | |
974 | return 0; | |
75e2c877 RS |
975 | } |
976 | ||
812b1537 | 977 | rand_drbg_lock(drbg); |
c16de9d8 DMSP |
978 | ret = rand_drbg_restart(drbg, buf, |
979 | (size_t)(unsigned int)num, | |
980 | (size_t)(8*randomness)); | |
812b1537 | 981 | rand_drbg_unlock(drbg); |
c16de9d8 DMSP |
982 | |
983 | return ret; | |
75e2c877 RS |
984 | } |
985 | ||
c16de9d8 | 986 | /* Implements the default OpenSSL RAND_seed() method */ |
75e2c877 RS |
987 | static int drbg_seed(const void *buf, int num) |
988 | { | |
989 | return drbg_add(buf, num, num); | |
990 | } | |
991 | ||
c16de9d8 | 992 | /* Implements the default OpenSSL RAND_status() method */ |
75e2c877 | 993 | static int drbg_status(void) |
12fb8c3d | 994 | { |
75e2c877 | 995 | int ret; |
a93ba405 | 996 | RAND_DRBG *drbg = RAND_DRBG_get0_master(); |
0b14a5b7 KR |
997 | |
998 | if (drbg == NULL) | |
999 | return 0; | |
75e2c877 | 1000 | |
812b1537 | 1001 | rand_drbg_lock(drbg); |
0b14a5b7 | 1002 | ret = drbg->state == DRBG_READY ? 1 : 0; |
812b1537 | 1003 | rand_drbg_unlock(drbg); |
75e2c877 | 1004 | return ret; |
12fb8c3d RS |
1005 | } |
1006 | ||
0b14a5b7 | 1007 | /* |
a93ba405 DMSP |
1008 | * Get the master DRBG. |
1009 | * Returns pointer to the DRBG on success, NULL on failure. | |
1010 | * | |
1011 | */ | |
1012 | RAND_DRBG *RAND_DRBG_get0_master(void) | |
1013 | { | |
1014 | if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) | |
1015 | return NULL; | |
1016 | ||
a73d990e | 1017 | return master_drbg; |
a93ba405 DMSP |
1018 | } |
1019 | ||
1020 | /* | |
1021 | * Get the public DRBG. | |
0b14a5b7 KR |
1022 | * Returns pointer to the DRBG on success, NULL on failure. |
1023 | */ | |
a93ba405 | 1024 | RAND_DRBG *RAND_DRBG_get0_public(void) |
0b14a5b7 | 1025 | { |
7caf122e KR |
1026 | RAND_DRBG *drbg; |
1027 | ||
c16de9d8 | 1028 | if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) |
0b14a5b7 KR |
1029 | return NULL; |
1030 | ||
a73d990e | 1031 | drbg = CRYPTO_THREAD_get_local(&public_drbg); |
7caf122e | 1032 | if (drbg == NULL) { |
272c0df8 BE |
1033 | if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND)) |
1034 | return NULL; | |
a73d990e DMSP |
1035 | drbg = drbg_setup(master_drbg); |
1036 | CRYPTO_THREAD_set_local(&public_drbg, drbg); | |
7caf122e KR |
1037 | } |
1038 | return drbg; | |
0b14a5b7 KR |
1039 | } |
1040 | ||
1041 | /* | |
a93ba405 | 1042 | * Get the private DRBG. |
0b14a5b7 KR |
1043 | * Returns pointer to the DRBG on success, NULL on failure. |
1044 | */ | |
a93ba405 | 1045 | RAND_DRBG *RAND_DRBG_get0_private(void) |
0b14a5b7 | 1046 | { |
7caf122e KR |
1047 | RAND_DRBG *drbg; |
1048 | ||
c16de9d8 | 1049 | if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) |
0b14a5b7 KR |
1050 | return NULL; |
1051 | ||
a73d990e | 1052 | drbg = CRYPTO_THREAD_get_local(&private_drbg); |
7caf122e | 1053 | if (drbg == NULL) { |
272c0df8 BE |
1054 | if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND)) |
1055 | return NULL; | |
a73d990e DMSP |
1056 | drbg = drbg_setup(master_drbg); |
1057 | CRYPTO_THREAD_set_local(&private_drbg, drbg); | |
7caf122e KR |
1058 | } |
1059 | return drbg; | |
0b14a5b7 KR |
1060 | } |
1061 | ||
75e2c877 RS |
1062 | RAND_METHOD rand_meth = { |
1063 | drbg_seed, | |
1064 | drbg_bytes, | |
ddc6a5c8 | 1065 | NULL, |
75e2c877 RS |
1066 | drbg_add, |
1067 | drbg_bytes, | |
1068 | drbg_status | |
1069 | }; | |
1070 | ||
1071 | RAND_METHOD *RAND_OpenSSL(void) | |
12fb8c3d | 1072 | { |
75e2c877 | 1073 | return &rand_meth; |
12fb8c3d | 1074 | } |