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12fb8c3d | 1 | /* |
3c7d0945 | 2 | * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved. |
12fb8c3d | 3 | * |
0db63de9 | 4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
12fb8c3d RS |
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 | 74 | |
8bf36651 SL |
75 | #define RAND_DRBG_TYPE_FLAGS ( \ |
76 | RAND_DRBG_FLAG_MASTER | RAND_DRBG_FLAG_PUBLIC | RAND_DRBG_FLAG_PRIVATE ) | |
77 | ||
78 | #define RAND_DRBG_TYPE_MASTER 0 | |
79 | #define RAND_DRBG_TYPE_PUBLIC 1 | |
80 | #define RAND_DRBG_TYPE_PRIVATE 2 | |
81 | ||
82 | /* Defaults */ | |
83 | static int rand_drbg_type[3] = { | |
84 | RAND_DRBG_TYPE, /* Master */ | |
85 | RAND_DRBG_TYPE, /* Public */ | |
86 | RAND_DRBG_TYPE /* Private */ | |
87 | }; | |
88 | static unsigned int rand_drbg_flags[3] = { | |
89 | RAND_DRBG_FLAGS | RAND_DRBG_FLAG_MASTER, /* Master */ | |
90 | RAND_DRBG_FLAGS | RAND_DRBG_FLAG_PUBLIC, /* Public */ | |
91 | RAND_DRBG_FLAGS | RAND_DRBG_FLAG_PRIVATE /* Private */ | |
92 | }; | |
31393fd9 | 93 | |
4917e911 DMSP |
94 | static unsigned int master_reseed_interval = MASTER_RESEED_INTERVAL; |
95 | static unsigned int slave_reseed_interval = SLAVE_RESEED_INTERVAL; | |
96 | ||
97 | static time_t master_reseed_time_interval = MASTER_RESEED_TIME_INTERVAL; | |
98 | static time_t slave_reseed_time_interval = SLAVE_RESEED_TIME_INTERVAL; | |
99 | ||
c402e943 DMSP |
100 | /* A logical OR of all used DRBG flag bits (currently there is only one) */ |
101 | static const unsigned int rand_drbg_used_flags = | |
8bf36651 SL |
102 | RAND_DRBG_FLAG_CTR_NO_DF | RAND_DRBG_FLAG_HMAC | RAND_DRBG_TYPE_FLAGS; |
103 | ||
c402e943 | 104 | |
8bf36651 | 105 | static RAND_DRBG *drbg_setup(RAND_DRBG *parent, int drbg_type); |
4f9dabbf DMSP |
106 | |
107 | static RAND_DRBG *rand_drbg_new(int secure, | |
108 | int type, | |
109 | unsigned int flags, | |
110 | RAND_DRBG *parent); | |
0b14a5b7 | 111 | |
8bf36651 SL |
112 | static int is_ctr(int type) |
113 | { | |
114 | switch (type) { | |
115 | case NID_aes_128_ctr: | |
116 | case NID_aes_192_ctr: | |
117 | case NID_aes_256_ctr: | |
118 | return 1; | |
119 | default: | |
120 | return 0; | |
121 | } | |
122 | } | |
123 | ||
124 | static int is_digest(int type) | |
125 | { | |
126 | switch (type) { | |
127 | case NID_sha1: | |
128 | case NID_sha224: | |
129 | case NID_sha256: | |
130 | case NID_sha384: | |
131 | case NID_sha512: | |
132 | case NID_sha512_224: | |
133 | case NID_sha512_256: | |
134 | case NID_sha3_224: | |
135 | case NID_sha3_256: | |
136 | case NID_sha3_384: | |
137 | case NID_sha3_512: | |
138 | return 1; | |
139 | default: | |
140 | return 0; | |
141 | } | |
142 | } | |
143 | ||
12fb8c3d | 144 | /* |
31393fd9 DMSP |
145 | * Set/initialize |drbg| to be of type |type|, with optional |flags|. |
146 | * | |
147 | * If |type| and |flags| are zero, use the defaults | |
efb8128a DMSP |
148 | * |
149 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 150 | */ |
31393fd9 | 151 | int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags) |
12fb8c3d RS |
152 | { |
153 | int ret = 1; | |
154 | ||
31393fd9 | 155 | if (type == 0 && flags == 0) { |
8bf36651 SL |
156 | type = rand_drbg_type[RAND_DRBG_TYPE_MASTER]; |
157 | flags = rand_drbg_flags[RAND_DRBG_TYPE_MASTER]; | |
158 | } | |
159 | ||
160 | /* If set is called multiple times - clear the old one */ | |
54f3e855 | 161 | if (drbg->type != 0 && (type != drbg->type || flags != drbg->flags)) { |
8bf36651 | 162 | drbg->meth->uninstantiate(drbg); |
54f3e855 BE |
163 | rand_pool_free(drbg->adin_pool); |
164 | drbg->adin_pool = NULL; | |
31393fd9 DMSP |
165 | } |
166 | ||
75e2c877 RS |
167 | drbg->state = DRBG_UNINITIALISED; |
168 | drbg->flags = flags; | |
31393fd9 | 169 | drbg->type = type; |
12fb8c3d | 170 | |
8bf36651 | 171 | if (type == 0) { |
12fb8c3d | 172 | /* Uninitialized; that's okay. */ |
54f3e855 | 173 | drbg->meth = NULL; |
12fb8c3d | 174 | return 1; |
8bf36651 | 175 | } else if (is_ctr(type)) { |
8212d505 | 176 | ret = drbg_ctr_init(drbg); |
8bf36651 SL |
177 | } else if (is_digest(type)) { |
178 | if (flags & RAND_DRBG_FLAG_HMAC) | |
179 | ret = drbg_hmac_init(drbg); | |
180 | else | |
181 | ret = drbg_hash_init(drbg); | |
182 | } else { | |
17209be8 BE |
183 | drbg->type = 0; |
184 | drbg->flags = 0; | |
185 | drbg->meth = NULL; | |
8bf36651 SL |
186 | RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE); |
187 | return 0; | |
12fb8c3d RS |
188 | } |
189 | ||
17209be8 BE |
190 | if (ret == 0) { |
191 | drbg->state = DRBG_ERROR; | |
12fb8c3d | 192 | RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG); |
17209be8 | 193 | } |
12fb8c3d RS |
194 | return ret; |
195 | } | |
196 | ||
31393fd9 DMSP |
197 | /* |
198 | * Set/initialize default |type| and |flag| for new drbg instances. | |
199 | * | |
200 | * Returns 1 on success, 0 on failure. | |
201 | */ | |
202 | int RAND_DRBG_set_defaults(int type, unsigned int flags) | |
203 | { | |
8bf36651 SL |
204 | int all; |
205 | if (!(is_digest(type) || is_ctr(type))) { | |
31393fd9 DMSP |
206 | RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_TYPE); |
207 | return 0; | |
31393fd9 DMSP |
208 | } |
209 | ||
c402e943 | 210 | if ((flags & ~rand_drbg_used_flags) != 0) { |
31393fd9 DMSP |
211 | RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS, RAND_R_UNSUPPORTED_DRBG_FLAGS); |
212 | return 0; | |
213 | } | |
214 | ||
8bf36651 SL |
215 | all = ((flags & RAND_DRBG_TYPE_FLAGS) == 0); |
216 | if (all || (flags & RAND_DRBG_FLAG_MASTER) != 0) { | |
217 | rand_drbg_type[RAND_DRBG_TYPE_MASTER] = type; | |
218 | rand_drbg_flags[RAND_DRBG_TYPE_MASTER] = flags | RAND_DRBG_FLAG_MASTER; | |
219 | } | |
220 | if (all || (flags & RAND_DRBG_FLAG_PUBLIC) != 0) { | |
221 | rand_drbg_type[RAND_DRBG_TYPE_PUBLIC] = type; | |
222 | rand_drbg_flags[RAND_DRBG_TYPE_PUBLIC] = flags | RAND_DRBG_FLAG_PUBLIC; | |
223 | } | |
224 | if (all || (flags & RAND_DRBG_FLAG_PRIVATE) != 0) { | |
225 | rand_drbg_type[RAND_DRBG_TYPE_PRIVATE] = type; | |
226 | rand_drbg_flags[RAND_DRBG_TYPE_PRIVATE] = flags | RAND_DRBG_FLAG_PRIVATE; | |
227 | } | |
228 | return 1; | |
31393fd9 DMSP |
229 | } |
230 | ||
231 | ||
12fb8c3d | 232 | /* |
4f9dabbf DMSP |
233 | * Allocate memory and initialize a new DRBG. The DRBG is allocated on |
234 | * the secure heap if |secure| is nonzero and the secure heap is enabled. | |
235 | * The |parent|, if not NULL, will be used as random source for reseeding. | |
a93ba405 DMSP |
236 | * |
237 | * Returns a pointer to the new DRBG instance on success, NULL on failure. | |
12fb8c3d | 238 | */ |
4f9dabbf DMSP |
239 | static RAND_DRBG *rand_drbg_new(int secure, |
240 | int type, | |
241 | unsigned int flags, | |
242 | RAND_DRBG *parent) | |
12fb8c3d | 243 | { |
b3d113ed P |
244 | RAND_DRBG *drbg = secure ? OPENSSL_secure_zalloc(sizeof(*drbg)) |
245 | : OPENSSL_zalloc(sizeof(*drbg)); | |
12fb8c3d | 246 | |
9d951a78 | 247 | if (drbg == NULL) { |
12fb8c3d | 248 | RANDerr(RAND_F_RAND_DRBG_NEW, ERR_R_MALLOC_FAILURE); |
f96ff4e9 | 249 | return NULL; |
12fb8c3d | 250 | } |
4f9dabbf DMSP |
251 | |
252 | drbg->secure = secure && CRYPTO_secure_allocated(drbg); | |
a35f607c | 253 | drbg->fork_count = rand_fork_count; |
75e2c877 | 254 | drbg->parent = parent; |
4917e911 DMSP |
255 | |
256 | if (parent == NULL) { | |
5bc6bcf8 DMSP |
257 | drbg->get_entropy = rand_drbg_get_entropy; |
258 | drbg->cleanup_entropy = rand_drbg_cleanup_entropy; | |
259 | #ifndef RAND_DRBG_GET_RANDOM_NONCE | |
260 | drbg->get_nonce = rand_drbg_get_nonce; | |
261 | drbg->cleanup_nonce = rand_drbg_cleanup_nonce; | |
262 | #endif | |
263 | ||
4917e911 DMSP |
264 | drbg->reseed_interval = master_reseed_interval; |
265 | drbg->reseed_time_interval = master_reseed_time_interval; | |
266 | } else { | |
5bc6bcf8 DMSP |
267 | drbg->get_entropy = rand_drbg_get_entropy; |
268 | drbg->cleanup_entropy = rand_drbg_cleanup_entropy; | |
269 | /* | |
270 | * Do not provide nonce callbacks, the child DRBGs will | |
271 | * obtain their nonce using random bits from the parent. | |
272 | */ | |
273 | ||
4917e911 DMSP |
274 | drbg->reseed_interval = slave_reseed_interval; |
275 | drbg->reseed_time_interval = slave_reseed_time_interval; | |
276 | } | |
277 | ||
efb8128a | 278 | if (RAND_DRBG_set(drbg, type, flags) == 0) |
75e2c877 RS |
279 | goto err; |
280 | ||
7caf122e KR |
281 | if (parent != NULL) { |
282 | rand_drbg_lock(parent); | |
283 | if (drbg->strength > parent->strength) { | |
284 | /* | |
285 | * We currently don't support the algorithm from NIST SP 800-90C | |
286 | * 10.1.2 to use a weaker DRBG as source | |
287 | */ | |
288 | rand_drbg_unlock(parent); | |
289 | RANDerr(RAND_F_RAND_DRBG_NEW, RAND_R_PARENT_STRENGTH_TOO_WEAK); | |
290 | goto err; | |
291 | } | |
292 | rand_drbg_unlock(parent); | |
35503b7c KR |
293 | } |
294 | ||
75e2c877 RS |
295 | return drbg; |
296 | ||
c2e33a05 | 297 | err: |
c5e0b3a6 | 298 | RAND_DRBG_free(drbg); |
4f9dabbf | 299 | |
75e2c877 | 300 | return NULL; |
12fb8c3d RS |
301 | } |
302 | ||
4f9dabbf DMSP |
303 | RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent) |
304 | { | |
305 | return rand_drbg_new(0, type, flags, parent); | |
306 | } | |
307 | ||
308 | RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent) | |
309 | { | |
310 | return rand_drbg_new(1, type, flags, parent); | |
311 | } | |
312 | ||
12fb8c3d | 313 | /* |
75e2c877 | 314 | * Uninstantiate |drbg| and free all memory. |
12fb8c3d | 315 | */ |
75e2c877 | 316 | void RAND_DRBG_free(RAND_DRBG *drbg) |
12fb8c3d | 317 | { |
c16de9d8 | 318 | if (drbg == NULL) |
12fb8c3d RS |
319 | return; |
320 | ||
8212d505 DMSP |
321 | if (drbg->meth != NULL) |
322 | drbg->meth->uninstantiate(drbg); | |
54f3e855 | 323 | rand_pool_free(drbg->adin_pool); |
4f9dabbf | 324 | CRYPTO_THREAD_lock_free(drbg->lock); |
75e2c877 | 325 | CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data); |
4f9dabbf DMSP |
326 | |
327 | if (drbg->secure) | |
328 | OPENSSL_secure_clear_free(drbg, sizeof(*drbg)); | |
329 | else | |
330 | OPENSSL_clear_free(drbg, sizeof(*drbg)); | |
12fb8c3d RS |
331 | } |
332 | ||
333 | /* | |
75e2c877 | 334 | * Instantiate |drbg|, after it has been initialized. Use |pers| and |
12fb8c3d | 335 | * |perslen| as prediction-resistance input. |
2139145b BK |
336 | * |
337 | * Requires that drbg->lock is already locked for write, if non-null. | |
efb8128a DMSP |
338 | * |
339 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 340 | */ |
75e2c877 | 341 | int RAND_DRBG_instantiate(RAND_DRBG *drbg, |
12fb8c3d RS |
342 | const unsigned char *pers, size_t perslen) |
343 | { | |
12fb8c3d | 344 | unsigned char *nonce = NULL, *entropy = NULL; |
aa048aef | 345 | size_t noncelen = 0, entropylen = 0; |
2a70d65b KR |
346 | size_t min_entropy = drbg->strength; |
347 | size_t min_entropylen = drbg->min_entropylen; | |
348 | size_t max_entropylen = drbg->max_entropylen; | |
12fb8c3d | 349 | |
aa048aef | 350 | if (perslen > drbg->max_perslen) { |
75e2c877 RS |
351 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, |
352 | RAND_R_PERSONALISATION_STRING_TOO_LONG); | |
12fb8c3d RS |
353 | goto end; |
354 | } | |
8212d505 | 355 | |
272c0df8 | 356 | if (drbg->meth == NULL) { |
8212d505 DMSP |
357 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, |
358 | RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED); | |
359 | goto end; | |
360 | } | |
361 | ||
75e2c877 RS |
362 | if (drbg->state != DRBG_UNINITIALISED) { |
363 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, | |
364 | drbg->state == DRBG_ERROR ? RAND_R_IN_ERROR_STATE | |
365 | : RAND_R_ALREADY_INSTANTIATED); | |
12fb8c3d RS |
366 | goto end; |
367 | } | |
368 | ||
75e2c877 | 369 | drbg->state = DRBG_ERROR; |
2a70d65b KR |
370 | |
371 | /* | |
372 | * NIST SP800-90Ar1 section 9.1 says you can combine getting the entropy | |
373 | * and nonce in 1 call by increasing the entropy with 50% and increasing | |
374 | * the minimum length to accomadate the length of the nonce. | |
375 | * We do this in case a nonce is require and get_nonce is NULL. | |
376 | */ | |
377 | if (drbg->min_noncelen > 0 && drbg->get_nonce == NULL) { | |
378 | min_entropy += drbg->strength / 2; | |
379 | min_entropylen += drbg->min_noncelen; | |
380 | max_entropylen += drbg->max_noncelen; | |
381 | } | |
382 | ||
a83dc59a BE |
383 | drbg->reseed_next_counter = tsan_load(&drbg->reseed_prop_counter); |
384 | if (drbg->reseed_next_counter) { | |
385 | drbg->reseed_next_counter++; | |
386 | if(!drbg->reseed_next_counter) | |
387 | drbg->reseed_next_counter = 1; | |
388 | } | |
389 | ||
75e2c877 | 390 | if (drbg->get_entropy != NULL) |
2a70d65b KR |
391 | entropylen = drbg->get_entropy(drbg, &entropy, min_entropy, |
392 | min_entropylen, max_entropylen, 0); | |
393 | if (entropylen < min_entropylen | |
c2e33a05 | 394 | || entropylen > max_entropylen) { |
75e2c877 | 395 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_ENTROPY); |
12fb8c3d RS |
396 | goto end; |
397 | } | |
398 | ||
2a70d65b | 399 | if (drbg->min_noncelen > 0 && drbg->get_nonce != NULL) { |
75e2c877 | 400 | noncelen = drbg->get_nonce(drbg, &nonce, drbg->strength / 2, |
aa048aef DMSP |
401 | drbg->min_noncelen, drbg->max_noncelen); |
402 | if (noncelen < drbg->min_noncelen || noncelen > drbg->max_noncelen) { | |
2a70d65b | 403 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_RETRIEVING_NONCE); |
12fb8c3d RS |
404 | goto end; |
405 | } | |
406 | } | |
407 | ||
8212d505 | 408 | if (!drbg->meth->instantiate(drbg, entropy, entropylen, |
12fb8c3d | 409 | nonce, noncelen, pers, perslen)) { |
75e2c877 | 410 | RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_INSTANTIATING_DRBG); |
12fb8c3d RS |
411 | goto end; |
412 | } | |
413 | ||
75e2c877 | 414 | drbg->state = DRBG_READY; |
8bf36651 | 415 | drbg->reseed_gen_counter = 1; |
08a65d96 | 416 | drbg->reseed_time = time(NULL); |
a83dc59a | 417 | tsan_store(&drbg->reseed_prop_counter, drbg->reseed_next_counter); |
12fb8c3d | 418 | |
c2e33a05 | 419 | end: |
75e2c877 | 420 | if (entropy != NULL && drbg->cleanup_entropy != NULL) |
6969a3f4 | 421 | drbg->cleanup_entropy(drbg, entropy, entropylen); |
c2e33a05 | 422 | if (nonce != NULL && drbg->cleanup_nonce != NULL) |
6969a3f4 | 423 | drbg->cleanup_nonce(drbg, nonce, noncelen); |
75e2c877 | 424 | if (drbg->state == DRBG_READY) |
12fb8c3d | 425 | return 1; |
12fb8c3d RS |
426 | return 0; |
427 | } | |
428 | ||
429 | /* | |
75e2c877 | 430 | * Uninstantiate |drbg|. Must be instantiated before it can be used. |
2139145b BK |
431 | * |
432 | * Requires that drbg->lock is already locked for write, if non-null. | |
efb8128a DMSP |
433 | * |
434 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 435 | */ |
75e2c877 | 436 | int RAND_DRBG_uninstantiate(RAND_DRBG *drbg) |
12fb8c3d | 437 | { |
8bf36651 | 438 | int index = -1, type, flags; |
272c0df8 | 439 | if (drbg->meth == NULL) { |
fb9c3ff5 | 440 | drbg->state = DRBG_ERROR; |
8212d505 DMSP |
441 | RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE, |
442 | RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED); | |
443 | return 0; | |
444 | } | |
445 | ||
efb8128a DMSP |
446 | /* Clear the entire drbg->ctr struct, then reset some important |
447 | * members of the drbg->ctr struct (e.g. keysize, df_ks) to their | |
448 | * initial values. | |
449 | */ | |
8212d505 | 450 | drbg->meth->uninstantiate(drbg); |
8bf36651 SL |
451 | |
452 | /* The reset uses the default values for type and flags */ | |
453 | if (drbg->flags & RAND_DRBG_FLAG_MASTER) | |
454 | index = RAND_DRBG_TYPE_MASTER; | |
455 | else if (drbg->flags & RAND_DRBG_FLAG_PRIVATE) | |
456 | index = RAND_DRBG_TYPE_PRIVATE; | |
457 | else if (drbg->flags & RAND_DRBG_FLAG_PUBLIC) | |
458 | index = RAND_DRBG_TYPE_PUBLIC; | |
459 | ||
460 | if (index != -1) { | |
461 | flags = rand_drbg_flags[index]; | |
462 | type = rand_drbg_type[index]; | |
463 | } else { | |
464 | flags = drbg->flags; | |
465 | type = drbg->type; | |
466 | } | |
467 | return RAND_DRBG_set(drbg, type, flags); | |
12fb8c3d RS |
468 | } |
469 | ||
470 | /* | |
c16de9d8 | 471 | * Reseed |drbg|, mixing in the specified data |
2139145b BK |
472 | * |
473 | * Requires that drbg->lock is already locked for write, if non-null. | |
efb8128a DMSP |
474 | * |
475 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 476 | */ |
75e2c877 | 477 | int RAND_DRBG_reseed(RAND_DRBG *drbg, |
eb238134 KR |
478 | const unsigned char *adin, size_t adinlen, |
479 | int prediction_resistance) | |
12fb8c3d RS |
480 | { |
481 | unsigned char *entropy = NULL; | |
aa048aef | 482 | size_t entropylen = 0; |
75e2c877 RS |
483 | |
484 | if (drbg->state == DRBG_ERROR) { | |
485 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_IN_ERROR_STATE); | |
486 | return 0; | |
487 | } | |
488 | if (drbg->state == DRBG_UNINITIALISED) { | |
489 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_NOT_INSTANTIATED); | |
490 | return 0; | |
12fb8c3d RS |
491 | } |
492 | ||
272c0df8 | 493 | if (adin == NULL) { |
12fb8c3d | 494 | adinlen = 0; |
272c0df8 | 495 | } else if (adinlen > drbg->max_adinlen) { |
75e2c877 RS |
496 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ADDITIONAL_INPUT_TOO_LONG); |
497 | return 0; | |
12fb8c3d RS |
498 | } |
499 | ||
75e2c877 | 500 | drbg->state = DRBG_ERROR; |
a83dc59a BE |
501 | |
502 | drbg->reseed_next_counter = tsan_load(&drbg->reseed_prop_counter); | |
503 | if (drbg->reseed_next_counter) { | |
504 | drbg->reseed_next_counter++; | |
505 | if(!drbg->reseed_next_counter) | |
506 | drbg->reseed_next_counter = 1; | |
507 | } | |
508 | ||
75e2c877 | 509 | if (drbg->get_entropy != NULL) |
aa048aef | 510 | entropylen = drbg->get_entropy(drbg, &entropy, drbg->strength, |
eb238134 KR |
511 | drbg->min_entropylen, |
512 | drbg->max_entropylen, | |
513 | prediction_resistance); | |
c16de9d8 | 514 | if (entropylen < drbg->min_entropylen |
c2e33a05 | 515 | || entropylen > drbg->max_entropylen) { |
75e2c877 | 516 | RANDerr(RAND_F_RAND_DRBG_RESEED, RAND_R_ERROR_RETRIEVING_ENTROPY); |
12fb8c3d RS |
517 | goto end; |
518 | } | |
519 | ||
8212d505 | 520 | if (!drbg->meth->reseed(drbg, entropy, entropylen, adin, adinlen)) |
12fb8c3d | 521 | goto end; |
a93ba405 | 522 | |
75e2c877 | 523 | drbg->state = DRBG_READY; |
8bf36651 | 524 | drbg->reseed_gen_counter = 1; |
08a65d96 | 525 | drbg->reseed_time = time(NULL); |
a83dc59a | 526 | tsan_store(&drbg->reseed_prop_counter, drbg->reseed_next_counter); |
12fb8c3d | 527 | |
c2e33a05 | 528 | end: |
75e2c877 | 529 | if (entropy != NULL && drbg->cleanup_entropy != NULL) |
6969a3f4 | 530 | drbg->cleanup_entropy(drbg, entropy, entropylen); |
75e2c877 | 531 | if (drbg->state == DRBG_READY) |
12fb8c3d | 532 | return 1; |
12fb8c3d RS |
533 | return 0; |
534 | } | |
535 | ||
c16de9d8 DMSP |
536 | /* |
537 | * Restart |drbg|, using the specified entropy or additional input | |
538 | * | |
539 | * Tries its best to get the drbg instantiated by all means, | |
540 | * regardless of its current state. | |
541 | * | |
542 | * Optionally, a |buffer| of |len| random bytes can be passed, | |
543 | * which is assumed to contain at least |entropy| bits of entropy. | |
544 | * | |
545 | * If |entropy| > 0, the buffer content is used as entropy input. | |
546 | * | |
547 | * If |entropy| == 0, the buffer content is used as additional input | |
548 | * | |
549 | * Returns 1 on success, 0 on failure. | |
550 | * | |
551 | * This function is used internally only. | |
552 | */ | |
553 | int rand_drbg_restart(RAND_DRBG *drbg, | |
554 | const unsigned char *buffer, size_t len, size_t entropy) | |
555 | { | |
556 | int reseeded = 0; | |
557 | const unsigned char *adin = NULL; | |
558 | size_t adinlen = 0; | |
559 | ||
31f32abb | 560 | if (drbg->seed_pool != NULL) { |
c16de9d8 | 561 | RANDerr(RAND_F_RAND_DRBG_RESTART, ERR_R_INTERNAL_ERROR); |
3064b551 | 562 | drbg->state = DRBG_ERROR; |
31f32abb BE |
563 | rand_pool_free(drbg->seed_pool); |
564 | drbg->seed_pool = NULL; | |
3064b551 | 565 | return 0; |
c16de9d8 DMSP |
566 | } |
567 | ||
568 | if (buffer != NULL) { | |
569 | if (entropy > 0) { | |
570 | if (drbg->max_entropylen < len) { | |
571 | RANDerr(RAND_F_RAND_DRBG_RESTART, | |
572 | RAND_R_ENTROPY_INPUT_TOO_LONG); | |
3064b551 | 573 | drbg->state = DRBG_ERROR; |
c16de9d8 DMSP |
574 | return 0; |
575 | } | |
576 | ||
577 | if (entropy > 8 * len) { | |
578 | RANDerr(RAND_F_RAND_DRBG_RESTART, RAND_R_ENTROPY_OUT_OF_RANGE); | |
3064b551 | 579 | drbg->state = DRBG_ERROR; |
c16de9d8 DMSP |
580 | return 0; |
581 | } | |
582 | ||
583 | /* will be picked up by the rand_drbg_get_entropy() callback */ | |
31f32abb BE |
584 | drbg->seed_pool = rand_pool_attach(buffer, len, entropy); |
585 | if (drbg->seed_pool == NULL) | |
c16de9d8 | 586 | return 0; |
c16de9d8 DMSP |
587 | } else { |
588 | if (drbg->max_adinlen < len) { | |
589 | RANDerr(RAND_F_RAND_DRBG_RESTART, | |
590 | RAND_R_ADDITIONAL_INPUT_TOO_LONG); | |
3064b551 | 591 | drbg->state = DRBG_ERROR; |
c16de9d8 DMSP |
592 | return 0; |
593 | } | |
594 | adin = buffer; | |
595 | adinlen = len; | |
596 | } | |
597 | } | |
598 | ||
599 | /* repair error state */ | |
efb8128a | 600 | if (drbg->state == DRBG_ERROR) |
c16de9d8 DMSP |
601 | RAND_DRBG_uninstantiate(drbg); |
602 | ||
603 | /* repair uninitialized state */ | |
604 | if (drbg->state == DRBG_UNINITIALISED) { | |
a93ba405 DMSP |
605 | /* reinstantiate drbg */ |
606 | RAND_DRBG_instantiate(drbg, | |
607 | (const unsigned char *) ossl_pers_string, | |
608 | sizeof(ossl_pers_string) - 1); | |
c16de9d8 DMSP |
609 | /* already reseeded. prevent second reseeding below */ |
610 | reseeded = (drbg->state == DRBG_READY); | |
611 | } | |
612 | ||
613 | /* refresh current state if entropy or additional input has been provided */ | |
614 | if (drbg->state == DRBG_READY) { | |
615 | if (adin != NULL) { | |
616 | /* | |
617 | * mix in additional input without reseeding | |
618 | * | |
619 | * Similar to RAND_DRBG_reseed(), but the provided additional | |
620 | * data |adin| is mixed into the current state without pulling | |
621 | * entropy from the trusted entropy source using get_entropy(). | |
622 | * This is not a reseeding in the strict sense of NIST SP 800-90A. | |
623 | */ | |
8212d505 | 624 | drbg->meth->reseed(drbg, adin, adinlen, NULL, 0); |
c16de9d8 DMSP |
625 | } else if (reseeded == 0) { |
626 | /* do a full reseeding if it has not been done yet above */ | |
eb238134 | 627 | RAND_DRBG_reseed(drbg, NULL, 0, 0); |
c16de9d8 DMSP |
628 | } |
629 | } | |
630 | ||
31f32abb BE |
631 | rand_pool_free(drbg->seed_pool); |
632 | drbg->seed_pool = NULL; | |
c16de9d8 DMSP |
633 | |
634 | return drbg->state == DRBG_READY; | |
635 | } | |
636 | ||
12fb8c3d RS |
637 | /* |
638 | * Generate |outlen| bytes into the buffer at |out|. Reseed if we need | |
639 | * to or if |prediction_resistance| is set. Additional input can be | |
640 | * sent in |adin| and |adinlen|. | |
c16de9d8 | 641 | * |
2139145b BK |
642 | * Requires that drbg->lock is already locked for write, if non-null. |
643 | * | |
c16de9d8 DMSP |
644 | * Returns 1 on success, 0 on failure. |
645 | * | |
12fb8c3d | 646 | */ |
75e2c877 | 647 | int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen, |
12fb8c3d RS |
648 | int prediction_resistance, |
649 | const unsigned char *adin, size_t adinlen) | |
650 | { | |
e0b625f9 DMSP |
651 | int reseed_required = 0; |
652 | ||
c16de9d8 DMSP |
653 | if (drbg->state != DRBG_READY) { |
654 | /* try to recover from previous errors */ | |
655 | rand_drbg_restart(drbg, NULL, 0, 0); | |
656 | ||
657 | if (drbg->state == DRBG_ERROR) { | |
658 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_IN_ERROR_STATE); | |
659 | return 0; | |
660 | } | |
661 | if (drbg->state == DRBG_UNINITIALISED) { | |
662 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_NOT_INSTANTIATED); | |
663 | return 0; | |
664 | } | |
12fb8c3d | 665 | } |
c16de9d8 | 666 | |
75e2c877 RS |
667 | if (outlen > drbg->max_request) { |
668 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG); | |
669 | return 0; | |
670 | } | |
aa048aef | 671 | if (adinlen > drbg->max_adinlen) { |
75e2c877 RS |
672 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_ADDITIONAL_INPUT_TOO_LONG); |
673 | return 0; | |
12fb8c3d RS |
674 | } |
675 | ||
a35f607c RS |
676 | if (drbg->fork_count != rand_fork_count) { |
677 | drbg->fork_count = rand_fork_count; | |
e0b625f9 | 678 | reseed_required = 1; |
a35f607c RS |
679 | } |
680 | ||
a93ba405 | 681 | if (drbg->reseed_interval > 0) { |
8bf36651 | 682 | if (drbg->reseed_gen_counter > drbg->reseed_interval) |
a93ba405 DMSP |
683 | reseed_required = 1; |
684 | } | |
08a65d96 DMSP |
685 | if (drbg->reseed_time_interval > 0) { |
686 | time_t now = time(NULL); | |
687 | if (now < drbg->reseed_time | |
688 | || now - drbg->reseed_time >= drbg->reseed_time_interval) | |
689 | reseed_required = 1; | |
690 | } | |
a83dc59a BE |
691 | if (drbg->parent != NULL) { |
692 | unsigned int reseed_counter = tsan_load(&drbg->reseed_prop_counter); | |
693 | if (reseed_counter > 0 | |
694 | && tsan_load(&drbg->parent->reseed_prop_counter) | |
695 | != reseed_counter) | |
a93ba405 DMSP |
696 | reseed_required = 1; |
697 | } | |
12fb8c3d | 698 | |
e0b625f9 | 699 | if (reseed_required || prediction_resistance) { |
eb238134 | 700 | if (!RAND_DRBG_reseed(drbg, adin, adinlen, prediction_resistance)) { |
75e2c877 RS |
701 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_RESEED_ERROR); |
702 | return 0; | |
12fb8c3d RS |
703 | } |
704 | adin = NULL; | |
705 | adinlen = 0; | |
706 | } | |
707 | ||
8212d505 | 708 | if (!drbg->meth->generate(drbg, out, outlen, adin, adinlen)) { |
75e2c877 RS |
709 | drbg->state = DRBG_ERROR; |
710 | RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_GENERATE_ERROR); | |
711 | return 0; | |
12fb8c3d | 712 | } |
75e2c877 | 713 | |
8bf36651 | 714 | drbg->reseed_gen_counter++; |
e0b625f9 | 715 | |
12fb8c3d | 716 | return 1; |
12fb8c3d RS |
717 | } |
718 | ||
20928ff6 KR |
719 | /* |
720 | * Generates |outlen| random bytes and stores them in |out|. It will | |
721 | * using the given |drbg| to generate the bytes. | |
722 | * | |
723 | * Requires that drbg->lock is already locked for write, if non-null. | |
724 | * | |
725 | * Returns 1 on success 0 on failure. | |
726 | */ | |
727 | int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen) | |
728 | { | |
729 | unsigned char *additional = NULL; | |
730 | size_t additional_len; | |
1648338b | 731 | size_t chunk; |
54f3e855 | 732 | size_t ret = 0; |
20928ff6 | 733 | |
54f3e855 BE |
734 | if (drbg->adin_pool == NULL) { |
735 | if (drbg->type == 0) | |
736 | goto err; | |
737 | drbg->adin_pool = rand_pool_new(0, 0, drbg->max_adinlen); | |
738 | if (drbg->adin_pool == NULL) | |
739 | goto err; | |
740 | } | |
741 | ||
742 | additional_len = rand_drbg_get_additional_data(drbg->adin_pool, | |
743 | &additional); | |
1648338b DMSP |
744 | |
745 | for ( ; outlen > 0; outlen -= chunk, out += chunk) { | |
746 | chunk = outlen; | |
747 | if (chunk > drbg->max_request) | |
748 | chunk = drbg->max_request; | |
749 | ret = RAND_DRBG_generate(drbg, out, chunk, 0, additional, additional_len); | |
750 | if (!ret) | |
751 | goto err; | |
752 | } | |
753 | ret = 1; | |
754 | ||
54f3e855 BE |
755 | err: |
756 | if (additional != NULL) | |
757 | rand_drbg_cleanup_additional_data(drbg->adin_pool, additional); | |
20928ff6 KR |
758 | |
759 | return ret; | |
760 | } | |
761 | ||
12fb8c3d | 762 | /* |
c16de9d8 DMSP |
763 | * Set the RAND_DRBG callbacks for obtaining entropy and nonce. |
764 | * | |
a73d990e DMSP |
765 | * Setting the callbacks is allowed only if the drbg has not been |
766 | * initialized yet. Otherwise, the operation will fail. | |
c16de9d8 | 767 | * |
a73d990e | 768 | * Returns 1 on success, 0 on failure. |
12fb8c3d | 769 | */ |
75e2c877 | 770 | int RAND_DRBG_set_callbacks(RAND_DRBG *drbg, |
c16de9d8 DMSP |
771 | RAND_DRBG_get_entropy_fn get_entropy, |
772 | RAND_DRBG_cleanup_entropy_fn cleanup_entropy, | |
773 | RAND_DRBG_get_nonce_fn get_nonce, | |
774 | RAND_DRBG_cleanup_nonce_fn cleanup_nonce) | |
12fb8c3d | 775 | { |
a83dc59a BE |
776 | if (drbg->state != DRBG_UNINITIALISED |
777 | || drbg->parent != NULL) | |
12fb8c3d | 778 | return 0; |
c16de9d8 DMSP |
779 | drbg->get_entropy = get_entropy; |
780 | drbg->cleanup_entropy = cleanup_entropy; | |
781 | drbg->get_nonce = get_nonce; | |
782 | drbg->cleanup_nonce = cleanup_nonce; | |
12fb8c3d RS |
783 | return 1; |
784 | } | |
785 | ||
786 | /* | |
75e2c877 | 787 | * Set the reseed interval. |
a93ba405 DMSP |
788 | * |
789 | * The drbg will reseed automatically whenever the number of generate | |
790 | * requests exceeds the given reseed interval. If the reseed interval | |
08a65d96 | 791 | * is 0, then this feature is disabled. |
a93ba405 DMSP |
792 | * |
793 | * Returns 1 on success, 0 on failure. | |
12fb8c3d | 794 | */ |
a93ba405 | 795 | int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval) |
12fb8c3d | 796 | { |
a93ba405 | 797 | if (interval > MAX_RESEED_INTERVAL) |
4c75ee85 | 798 | return 0; |
75e2c877 | 799 | drbg->reseed_interval = interval; |
4c75ee85 | 800 | return 1; |
12fb8c3d RS |
801 | } |
802 | ||
08a65d96 DMSP |
803 | /* |
804 | * Set the reseed time interval. | |
805 | * | |
806 | * The drbg will reseed automatically whenever the time elapsed since | |
807 | * the last reseeding exceeds the given reseed time interval. For safety, | |
808 | * a reseeding will also occur if the clock has been reset to a smaller | |
809 | * value. | |
810 | * | |
811 | * Returns 1 on success, 0 on failure. | |
812 | */ | |
813 | int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval) | |
814 | { | |
815 | if (interval > MAX_RESEED_TIME_INTERVAL) | |
816 | return 0; | |
817 | drbg->reseed_time_interval = interval; | |
818 | return 1; | |
819 | } | |
820 | ||
4917e911 DMSP |
821 | /* |
822 | * Set the default values for reseed (time) intervals of new DRBG instances | |
823 | * | |
824 | * The default values can be set independently for master DRBG instances | |
825 | * (without a parent) and slave DRBG instances (with parent). | |
826 | * | |
827 | * Returns 1 on success, 0 on failure. | |
828 | */ | |
829 | ||
830 | int RAND_DRBG_set_reseed_defaults( | |
831 | unsigned int _master_reseed_interval, | |
832 | unsigned int _slave_reseed_interval, | |
833 | time_t _master_reseed_time_interval, | |
834 | time_t _slave_reseed_time_interval | |
835 | ) | |
836 | { | |
837 | if (_master_reseed_interval > MAX_RESEED_INTERVAL | |
838 | || _slave_reseed_interval > MAX_RESEED_INTERVAL) | |
839 | return 0; | |
840 | ||
841 | if (_master_reseed_time_interval > MAX_RESEED_TIME_INTERVAL | |
842 | || _slave_reseed_time_interval > MAX_RESEED_TIME_INTERVAL) | |
843 | return 0; | |
844 | ||
845 | master_reseed_interval = _master_reseed_interval; | |
846 | slave_reseed_interval = _slave_reseed_interval; | |
847 | ||
848 | master_reseed_time_interval = _master_reseed_time_interval; | |
849 | slave_reseed_time_interval = _slave_reseed_time_interval; | |
850 | ||
851 | return 1; | |
852 | } | |
3ce1c27b DMSP |
853 | |
854 | /* | |
855 | * Locks the given drbg. Locking a drbg which does not have locking | |
856 | * enabled is considered a successful no-op. | |
857 | * | |
858 | * Returns 1 on success, 0 on failure. | |
859 | */ | |
812b1537 | 860 | int rand_drbg_lock(RAND_DRBG *drbg) |
3ce1c27b DMSP |
861 | { |
862 | if (drbg->lock != NULL) | |
863 | return CRYPTO_THREAD_write_lock(drbg->lock); | |
864 | ||
865 | return 1; | |
866 | } | |
867 | ||
868 | /* | |
869 | * Unlocks the given drbg. Unlocking a drbg which does not have locking | |
870 | * enabled is considered a successful no-op. | |
871 | * | |
872 | * Returns 1 on success, 0 on failure. | |
873 | */ | |
812b1537 | 874 | int rand_drbg_unlock(RAND_DRBG *drbg) |
3ce1c27b DMSP |
875 | { |
876 | if (drbg->lock != NULL) | |
877 | return CRYPTO_THREAD_unlock(drbg->lock); | |
878 | ||
879 | return 1; | |
880 | } | |
881 | ||
882 | /* | |
883 | * Enables locking for the given drbg | |
884 | * | |
885 | * Locking can only be enabled if the random generator | |
886 | * is in the uninitialized state. | |
887 | * | |
888 | * Returns 1 on success, 0 on failure. | |
889 | */ | |
812b1537 | 890 | int rand_drbg_enable_locking(RAND_DRBG *drbg) |
3ce1c27b DMSP |
891 | { |
892 | if (drbg->state != DRBG_UNINITIALISED) { | |
893 | RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, | |
894 | RAND_R_DRBG_ALREADY_INITIALIZED); | |
895 | return 0; | |
896 | } | |
897 | ||
898 | if (drbg->lock == NULL) { | |
4f9dabbf | 899 | if (drbg->parent != NULL && drbg->parent->lock == NULL) { |
3ce1c27b DMSP |
900 | RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, |
901 | RAND_R_PARENT_LOCKING_NOT_ENABLED); | |
902 | return 0; | |
903 | } | |
904 | ||
905 | drbg->lock = CRYPTO_THREAD_lock_new(); | |
906 | if (drbg->lock == NULL) { | |
907 | RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, | |
908 | RAND_R_FAILED_TO_CREATE_LOCK); | |
909 | return 0; | |
910 | } | |
911 | } | |
912 | ||
913 | return 1; | |
914 | } | |
915 | ||
12fb8c3d RS |
916 | /* |
917 | * Get and set the EXDATA | |
918 | */ | |
75e2c877 RS |
919 | int RAND_DRBG_set_ex_data(RAND_DRBG *drbg, int idx, void *arg) |
920 | { | |
921 | return CRYPTO_set_ex_data(&drbg->ex_data, idx, arg); | |
922 | } | |
923 | ||
924 | void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx) | |
925 | { | |
926 | return CRYPTO_get_ex_data(&drbg->ex_data, idx); | |
927 | } | |
928 | ||
929 | ||
930 | /* | |
931 | * The following functions provide a RAND_METHOD that works on the | |
932 | * global DRBG. They lock. | |
933 | */ | |
934 | ||
0b14a5b7 | 935 | /* |
933033b6 DMSP |
936 | * Allocates a new global DRBG on the secure heap (if enabled) and |
937 | * initializes it with default settings. | |
a93ba405 DMSP |
938 | * |
939 | * Returns a pointer to the new DRBG instance on success, NULL on failure. | |
0b14a5b7 | 940 | */ |
8bf36651 | 941 | static RAND_DRBG *drbg_setup(RAND_DRBG *parent, int drbg_type) |
0b14a5b7 | 942 | { |
933033b6 | 943 | RAND_DRBG *drbg; |
0b14a5b7 | 944 | |
8bf36651 SL |
945 | drbg = RAND_DRBG_secure_new(rand_drbg_type[drbg_type], |
946 | rand_drbg_flags[drbg_type], parent); | |
933033b6 DMSP |
947 | if (drbg == NULL) |
948 | return NULL; | |
949 | ||
7caf122e KR |
950 | /* Only the master DRBG needs to have a lock */ |
951 | if (parent == NULL && rand_drbg_enable_locking(drbg) == 0) | |
933033b6 | 952 | goto err; |
a93ba405 | 953 | |
a93ba405 | 954 | /* enable seed propagation */ |
a83dc59a | 955 | tsan_store(&drbg->reseed_prop_counter, 1); |
a93ba405 | 956 | |
c16de9d8 | 957 | /* |
43687d68 | 958 | * Ignore instantiation error to support just-in-time instantiation. |
c16de9d8 DMSP |
959 | * |
960 | * The state of the drbg will be checked in RAND_DRBG_generate() and | |
961 | * an automatic recovery is attempted. | |
962 | */ | |
43687d68 DMSP |
963 | (void)RAND_DRBG_instantiate(drbg, |
964 | (const unsigned char *) ossl_pers_string, | |
965 | sizeof(ossl_pers_string) - 1); | |
933033b6 DMSP |
966 | return drbg; |
967 | ||
968 | err: | |
4f9dabbf | 969 | RAND_DRBG_free(drbg); |
933033b6 | 970 | return NULL; |
0b14a5b7 KR |
971 | } |
972 | ||
973 | /* | |
974 | * Initialize the global DRBGs on first use. | |
975 | * Returns 1 on success, 0 on failure. | |
976 | */ | |
c16de9d8 | 977 | DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init) |
0b14a5b7 | 978 | { |
39571fca DMSP |
979 | /* |
980 | * ensure that libcrypto is initialized, otherwise the | |
981 | * DRBG locks are not cleaned up properly | |
982 | */ | |
983 | if (!OPENSSL_init_crypto(0, NULL)) | |
984 | return 0; | |
985 | ||
272c0df8 BE |
986 | if (!CRYPTO_THREAD_init_local(&private_drbg, NULL)) |
987 | return 0; | |
0b14a5b7 | 988 | |
272c0df8 BE |
989 | if (!CRYPTO_THREAD_init_local(&public_drbg, NULL)) |
990 | goto err1; | |
7caf122e | 991 | |
8bf36651 | 992 | master_drbg = drbg_setup(NULL, RAND_DRBG_TYPE_MASTER); |
272c0df8 BE |
993 | if (master_drbg == NULL) |
994 | goto err2; | |
0b14a5b7 | 995 | |
933033b6 | 996 | return 1; |
272c0df8 BE |
997 | |
998 | err2: | |
999 | CRYPTO_THREAD_cleanup_local(&public_drbg); | |
1000 | err1: | |
1001 | CRYPTO_THREAD_cleanup_local(&private_drbg); | |
1002 | return 0; | |
0b14a5b7 KR |
1003 | } |
1004 | ||
0b14a5b7 | 1005 | /* Clean up the global DRBGs before exit */ |
c16de9d8 | 1006 | void rand_drbg_cleanup_int(void) |
0b14a5b7 | 1007 | { |
bf7ae750 BE |
1008 | if (master_drbg != NULL) { |
1009 | RAND_DRBG_free(master_drbg); | |
1010 | master_drbg = NULL; | |
933033b6 | 1011 | |
bf7ae750 BE |
1012 | CRYPTO_THREAD_cleanup_local(&private_drbg); |
1013 | CRYPTO_THREAD_cleanup_local(&public_drbg); | |
1014 | } | |
7caf122e KR |
1015 | } |
1016 | ||
3cb7c5cf | 1017 | void drbg_delete_thread_state(void) |
7caf122e KR |
1018 | { |
1019 | RAND_DRBG *drbg; | |
1020 | ||
a73d990e | 1021 | drbg = CRYPTO_THREAD_get_local(&public_drbg); |
272c0df8 | 1022 | CRYPTO_THREAD_set_local(&public_drbg, NULL); |
7caf122e KR |
1023 | RAND_DRBG_free(drbg); |
1024 | ||
a73d990e | 1025 | drbg = CRYPTO_THREAD_get_local(&private_drbg); |
272c0df8 | 1026 | CRYPTO_THREAD_set_local(&private_drbg, NULL); |
7caf122e | 1027 | RAND_DRBG_free(drbg); |
0b14a5b7 KR |
1028 | } |
1029 | ||
c16de9d8 | 1030 | /* Implements the default OpenSSL RAND_bytes() method */ |
75e2c877 RS |
1031 | static int drbg_bytes(unsigned char *out, int count) |
1032 | { | |
f61f62ea | 1033 | int ret; |
a93ba405 | 1034 | RAND_DRBG *drbg = RAND_DRBG_get0_public(); |
75e2c877 | 1035 | |
0b14a5b7 KR |
1036 | if (drbg == NULL) |
1037 | return 0; | |
1038 | ||
f61f62ea | 1039 | ret = RAND_DRBG_bytes(drbg, out, count); |
f61f62ea | 1040 | |
75e2c877 RS |
1041 | return ret; |
1042 | } | |
1043 | ||
8817215d DMSP |
1044 | /* |
1045 | * Calculates the minimum length of a full entropy buffer | |
1046 | * which is necessary to seed (i.e. instantiate) the DRBG | |
1047 | * successfully. | |
8817215d | 1048 | */ |
1c615e4c | 1049 | size_t rand_drbg_seedlen(RAND_DRBG *drbg) |
8817215d DMSP |
1050 | { |
1051 | /* | |
1052 | * If no os entropy source is available then RAND_seed(buffer, bufsize) | |
1053 | * is expected to succeed if and only if the buffer length satisfies | |
1054 | * the following requirements, which follow from the calculations | |
1055 | * in RAND_DRBG_instantiate(). | |
1056 | */ | |
1057 | size_t min_entropy = drbg->strength; | |
1058 | size_t min_entropylen = drbg->min_entropylen; | |
1059 | ||
1060 | /* | |
1061 | * Extra entropy for the random nonce in the absence of a | |
1062 | * get_nonce callback, see comment in RAND_DRBG_instantiate(). | |
1063 | */ | |
1064 | if (drbg->min_noncelen > 0 && drbg->get_nonce == NULL) { | |
1065 | min_entropy += drbg->strength / 2; | |
1066 | min_entropylen += drbg->min_noncelen; | |
1067 | } | |
1068 | ||
1069 | /* | |
1070 | * Convert entropy requirement from bits to bytes | |
1071 | * (dividing by 8 without rounding upwards, because | |
1072 | * all entropy requirements are divisible by 8). | |
1073 | */ | |
1074 | min_entropy >>= 3; | |
1075 | ||
1076 | /* Return a value that satisfies both requirements */ | |
1077 | return min_entropy > min_entropylen ? min_entropy : min_entropylen; | |
1078 | } | |
1079 | ||
c16de9d8 | 1080 | /* Implements the default OpenSSL RAND_add() method */ |
75e2c877 RS |
1081 | static int drbg_add(const void *buf, int num, double randomness) |
1082 | { | |
c16de9d8 | 1083 | int ret = 0; |
a93ba405 | 1084 | RAND_DRBG *drbg = RAND_DRBG_get0_master(); |
8817215d | 1085 | size_t buflen; |
59f90557 | 1086 | size_t seedlen; |
75e2c877 | 1087 | |
c16de9d8 DMSP |
1088 | if (drbg == NULL) |
1089 | return 0; | |
75e2c877 | 1090 | |
c16de9d8 DMSP |
1091 | if (num < 0 || randomness < 0.0) |
1092 | return 0; | |
75e2c877 | 1093 | |
4011bab1 | 1094 | rand_drbg_lock(drbg); |
59f90557 DMSP |
1095 | seedlen = rand_drbg_seedlen(drbg); |
1096 | ||
8817215d DMSP |
1097 | buflen = (size_t)num; |
1098 | ||
1099 | if (buflen < seedlen || randomness < (double) seedlen) { | |
1100 | #if defined(OPENSSL_RAND_SEED_NONE) | |
1101 | /* | |
1102 | * If no os entropy source is available, a reseeding will fail | |
1103 | * inevitably. So we use a trick to mix the buffer contents into | |
1104 | * the DRBG state without forcing a reseeding: we generate a | |
1105 | * dummy random byte, using the buffer content as additional data. | |
4011bab1 | 1106 | * Note: This won't work with RAND_DRBG_FLAG_CTR_NO_DF. |
8817215d DMSP |
1107 | */ |
1108 | unsigned char dummy[1]; | |
1109 | ||
4011bab1 BE |
1110 | ret = RAND_DRBG_generate(drbg, dummy, sizeof(dummy), 0, buf, buflen); |
1111 | rand_drbg_unlock(drbg); | |
1112 | return ret; | |
8817215d DMSP |
1113 | #else |
1114 | /* | |
1115 | * If an os entropy source is avaible then we declare the buffer content | |
1116 | * as additional data by setting randomness to zero and trigger a regular | |
1117 | * reseeding. | |
1118 | */ | |
1119 | randomness = 0.0; | |
1120 | #endif | |
1121 | } | |
1122 | ||
1123 | ||
1124 | if (randomness > (double)seedlen) { | |
c16de9d8 DMSP |
1125 | /* |
1126 | * The purpose of this check is to bound |randomness| by a | |
1127 | * relatively small value in order to prevent an integer | |
1128 | * overflow when multiplying by 8 in the rand_drbg_restart() | |
3064b551 DMSP |
1129 | * call below. Note that randomness is measured in bytes, |
1130 | * not bits, so this value corresponds to eight times the | |
1131 | * security strength. | |
c16de9d8 | 1132 | */ |
8817215d | 1133 | randomness = (double)seedlen; |
75e2c877 RS |
1134 | } |
1135 | ||
8817215d | 1136 | ret = rand_drbg_restart(drbg, buf, buflen, (size_t)(8 * randomness)); |
812b1537 | 1137 | rand_drbg_unlock(drbg); |
c16de9d8 DMSP |
1138 | |
1139 | return ret; | |
75e2c877 RS |
1140 | } |
1141 | ||
c16de9d8 | 1142 | /* Implements the default OpenSSL RAND_seed() method */ |
75e2c877 RS |
1143 | static int drbg_seed(const void *buf, int num) |
1144 | { | |
1145 | return drbg_add(buf, num, num); | |
1146 | } | |
1147 | ||
c16de9d8 | 1148 | /* Implements the default OpenSSL RAND_status() method */ |
75e2c877 | 1149 | static int drbg_status(void) |
12fb8c3d | 1150 | { |
75e2c877 | 1151 | int ret; |
a93ba405 | 1152 | RAND_DRBG *drbg = RAND_DRBG_get0_master(); |
0b14a5b7 KR |
1153 | |
1154 | if (drbg == NULL) | |
1155 | return 0; | |
75e2c877 | 1156 | |
812b1537 | 1157 | rand_drbg_lock(drbg); |
0b14a5b7 | 1158 | ret = drbg->state == DRBG_READY ? 1 : 0; |
812b1537 | 1159 | rand_drbg_unlock(drbg); |
75e2c877 | 1160 | return ret; |
12fb8c3d RS |
1161 | } |
1162 | ||
0b14a5b7 | 1163 | /* |
a93ba405 DMSP |
1164 | * Get the master DRBG. |
1165 | * Returns pointer to the DRBG on success, NULL on failure. | |
1166 | * | |
1167 | */ | |
1168 | RAND_DRBG *RAND_DRBG_get0_master(void) | |
1169 | { | |
1170 | if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) | |
1171 | return NULL; | |
1172 | ||
a73d990e | 1173 | return master_drbg; |
a93ba405 DMSP |
1174 | } |
1175 | ||
1176 | /* | |
1177 | * Get the public DRBG. | |
0b14a5b7 KR |
1178 | * Returns pointer to the DRBG on success, NULL on failure. |
1179 | */ | |
a93ba405 | 1180 | RAND_DRBG *RAND_DRBG_get0_public(void) |
0b14a5b7 | 1181 | { |
7caf122e KR |
1182 | RAND_DRBG *drbg; |
1183 | ||
c16de9d8 | 1184 | if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) |
0b14a5b7 KR |
1185 | return NULL; |
1186 | ||
a73d990e | 1187 | drbg = CRYPTO_THREAD_get_local(&public_drbg); |
7caf122e | 1188 | if (drbg == NULL) { |
272c0df8 BE |
1189 | if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND)) |
1190 | return NULL; | |
8bf36651 | 1191 | drbg = drbg_setup(master_drbg, RAND_DRBG_TYPE_PUBLIC); |
a73d990e | 1192 | CRYPTO_THREAD_set_local(&public_drbg, drbg); |
7caf122e KR |
1193 | } |
1194 | return drbg; | |
0b14a5b7 KR |
1195 | } |
1196 | ||
1197 | /* | |
a93ba405 | 1198 | * Get the private DRBG. |
0b14a5b7 KR |
1199 | * Returns pointer to the DRBG on success, NULL on failure. |
1200 | */ | |
a93ba405 | 1201 | RAND_DRBG *RAND_DRBG_get0_private(void) |
0b14a5b7 | 1202 | { |
7caf122e KR |
1203 | RAND_DRBG *drbg; |
1204 | ||
c16de9d8 | 1205 | if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) |
0b14a5b7 KR |
1206 | return NULL; |
1207 | ||
a73d990e | 1208 | drbg = CRYPTO_THREAD_get_local(&private_drbg); |
7caf122e | 1209 | if (drbg == NULL) { |
272c0df8 BE |
1210 | if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND)) |
1211 | return NULL; | |
8bf36651 | 1212 | drbg = drbg_setup(master_drbg, RAND_DRBG_TYPE_PRIVATE); |
a73d990e | 1213 | CRYPTO_THREAD_set_local(&private_drbg, drbg); |
7caf122e KR |
1214 | } |
1215 | return drbg; | |
0b14a5b7 KR |
1216 | } |
1217 | ||
75e2c877 RS |
1218 | RAND_METHOD rand_meth = { |
1219 | drbg_seed, | |
1220 | drbg_bytes, | |
ddc6a5c8 | 1221 | NULL, |
75e2c877 RS |
1222 | drbg_add, |
1223 | drbg_bytes, | |
1224 | drbg_status | |
1225 | }; | |
1226 | ||
1227 | RAND_METHOD *RAND_OpenSSL(void) | |
12fb8c3d | 1228 | { |
75e2c877 | 1229 | return &rand_meth; |
12fb8c3d | 1230 | } |