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1 | /* | |
2 | * Scatterlist Cryptographic API. | |
3 | * | |
4 | * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> | |
5 | * Copyright (c) 2002 David S. Miller (davem@redhat.com) | |
6 | * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au> | |
7 | * | |
8 | * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no> | |
9 | * and Nettle, by Niels Möller. | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify it | |
12 | * under the terms of the GNU General Public License as published by the Free | |
13 | * Software Foundation; either version 2 of the License, or (at your option) | |
14 | * any later version. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <linux/err.h> | |
19 | #include <linux/errno.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/kmod.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/param.h> | |
24 | #include <linux/sched.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/string.h> | |
27 | #include "internal.h" | |
28 | ||
29 | LIST_HEAD(crypto_alg_list); | |
30 | EXPORT_SYMBOL_GPL(crypto_alg_list); | |
31 | DECLARE_RWSEM(crypto_alg_sem); | |
32 | EXPORT_SYMBOL_GPL(crypto_alg_sem); | |
33 | ||
34 | BLOCKING_NOTIFIER_HEAD(crypto_chain); | |
35 | EXPORT_SYMBOL_GPL(crypto_chain); | |
36 | ||
37 | static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg) | |
38 | { | |
39 | atomic_inc(&alg->cra_refcnt); | |
40 | return alg; | |
41 | } | |
42 | ||
43 | struct crypto_alg *crypto_mod_get(struct crypto_alg *alg) | |
44 | { | |
45 | return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL; | |
46 | } | |
47 | EXPORT_SYMBOL_GPL(crypto_mod_get); | |
48 | ||
49 | void crypto_mod_put(struct crypto_alg *alg) | |
50 | { | |
51 | struct module *module = alg->cra_module; | |
52 | ||
53 | crypto_alg_put(alg); | |
54 | module_put(module); | |
55 | } | |
56 | EXPORT_SYMBOL_GPL(crypto_mod_put); | |
57 | ||
58 | static inline int crypto_is_test_larval(struct crypto_larval *larval) | |
59 | { | |
60 | return larval->alg.cra_driver_name[0]; | |
61 | } | |
62 | ||
63 | static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type, | |
64 | u32 mask) | |
65 | { | |
66 | struct crypto_alg *q, *alg = NULL; | |
67 | int best = -2; | |
68 | ||
69 | list_for_each_entry(q, &crypto_alg_list, cra_list) { | |
70 | int exact, fuzzy; | |
71 | ||
72 | if (crypto_is_moribund(q)) | |
73 | continue; | |
74 | ||
75 | if ((q->cra_flags ^ type) & mask) | |
76 | continue; | |
77 | ||
78 | if (crypto_is_larval(q) && | |
79 | !crypto_is_test_larval((struct crypto_larval *)q) && | |
80 | ((struct crypto_larval *)q)->mask != mask) | |
81 | continue; | |
82 | ||
83 | exact = !strcmp(q->cra_driver_name, name); | |
84 | fuzzy = !strcmp(q->cra_name, name); | |
85 | if (!exact && !(fuzzy && q->cra_priority > best)) | |
86 | continue; | |
87 | ||
88 | if (unlikely(!crypto_mod_get(q))) | |
89 | continue; | |
90 | ||
91 | best = q->cra_priority; | |
92 | if (alg) | |
93 | crypto_mod_put(alg); | |
94 | alg = q; | |
95 | ||
96 | if (exact) | |
97 | break; | |
98 | } | |
99 | ||
100 | return alg; | |
101 | } | |
102 | ||
103 | static void crypto_larval_destroy(struct crypto_alg *alg) | |
104 | { | |
105 | struct crypto_larval *larval = (void *)alg; | |
106 | ||
107 | BUG_ON(!crypto_is_larval(alg)); | |
108 | if (larval->adult) | |
109 | crypto_mod_put(larval->adult); | |
110 | kfree(larval); | |
111 | } | |
112 | ||
113 | struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask) | |
114 | { | |
115 | struct crypto_larval *larval; | |
116 | ||
117 | larval = kzalloc(sizeof(*larval), GFP_KERNEL); | |
118 | if (!larval) | |
119 | return ERR_PTR(-ENOMEM); | |
120 | ||
121 | larval->mask = mask; | |
122 | larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type; | |
123 | larval->alg.cra_priority = -1; | |
124 | larval->alg.cra_destroy = crypto_larval_destroy; | |
125 | ||
126 | strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME); | |
127 | init_completion(&larval->completion); | |
128 | ||
129 | return larval; | |
130 | } | |
131 | EXPORT_SYMBOL_GPL(crypto_larval_alloc); | |
132 | ||
133 | static struct crypto_alg *crypto_larval_add(const char *name, u32 type, | |
134 | u32 mask) | |
135 | { | |
136 | struct crypto_alg *alg; | |
137 | struct crypto_larval *larval; | |
138 | ||
139 | larval = crypto_larval_alloc(name, type, mask); | |
140 | if (IS_ERR(larval)) | |
141 | return ERR_CAST(larval); | |
142 | ||
143 | atomic_set(&larval->alg.cra_refcnt, 2); | |
144 | ||
145 | down_write(&crypto_alg_sem); | |
146 | alg = __crypto_alg_lookup(name, type, mask); | |
147 | if (!alg) { | |
148 | alg = &larval->alg; | |
149 | list_add(&alg->cra_list, &crypto_alg_list); | |
150 | } | |
151 | up_write(&crypto_alg_sem); | |
152 | ||
153 | if (alg != &larval->alg) | |
154 | kfree(larval); | |
155 | ||
156 | return alg; | |
157 | } | |
158 | ||
159 | void crypto_larval_kill(struct crypto_alg *alg) | |
160 | { | |
161 | struct crypto_larval *larval = (void *)alg; | |
162 | ||
163 | down_write(&crypto_alg_sem); | |
164 | list_del(&alg->cra_list); | |
165 | up_write(&crypto_alg_sem); | |
166 | complete_all(&larval->completion); | |
167 | crypto_alg_put(alg); | |
168 | } | |
169 | EXPORT_SYMBOL_GPL(crypto_larval_kill); | |
170 | ||
171 | static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg) | |
172 | { | |
173 | struct crypto_larval *larval = (void *)alg; | |
174 | long timeout; | |
175 | ||
176 | timeout = wait_for_completion_interruptible_timeout( | |
177 | &larval->completion, 60 * HZ); | |
178 | ||
179 | alg = larval->adult; | |
180 | if (timeout < 0) | |
181 | alg = ERR_PTR(-EINTR); | |
182 | else if (!timeout) | |
183 | alg = ERR_PTR(-ETIMEDOUT); | |
184 | else if (!alg) | |
185 | alg = ERR_PTR(-ENOENT); | |
186 | else if (crypto_is_test_larval(larval) && | |
187 | !(alg->cra_flags & CRYPTO_ALG_TESTED)) | |
188 | alg = ERR_PTR(-EAGAIN); | |
189 | else if (!crypto_mod_get(alg)) | |
190 | alg = ERR_PTR(-EAGAIN); | |
191 | crypto_mod_put(&larval->alg); | |
192 | ||
193 | return alg; | |
194 | } | |
195 | ||
196 | struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, u32 mask) | |
197 | { | |
198 | struct crypto_alg *alg; | |
199 | ||
200 | down_read(&crypto_alg_sem); | |
201 | alg = __crypto_alg_lookup(name, type, mask); | |
202 | up_read(&crypto_alg_sem); | |
203 | ||
204 | return alg; | |
205 | } | |
206 | EXPORT_SYMBOL_GPL(crypto_alg_lookup); | |
207 | ||
208 | struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask) | |
209 | { | |
210 | struct crypto_alg *alg; | |
211 | ||
212 | if (!name) | |
213 | return ERR_PTR(-ENOENT); | |
214 | ||
215 | mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD); | |
216 | type &= mask; | |
217 | ||
218 | alg = crypto_alg_lookup(name, type, mask); | |
219 | if (!alg) { | |
220 | request_module("%s", name); | |
221 | ||
222 | if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask & | |
223 | CRYPTO_ALG_NEED_FALLBACK)) | |
224 | request_module("%s-all", name); | |
225 | ||
226 | alg = crypto_alg_lookup(name, type, mask); | |
227 | } | |
228 | ||
229 | if (alg) | |
230 | return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg; | |
231 | ||
232 | return crypto_larval_add(name, type, mask); | |
233 | } | |
234 | EXPORT_SYMBOL_GPL(crypto_larval_lookup); | |
235 | ||
236 | int crypto_probing_notify(unsigned long val, void *v) | |
237 | { | |
238 | int ok; | |
239 | ||
240 | ok = blocking_notifier_call_chain(&crypto_chain, val, v); | |
241 | if (ok == NOTIFY_DONE) { | |
242 | request_module("cryptomgr"); | |
243 | ok = blocking_notifier_call_chain(&crypto_chain, val, v); | |
244 | } | |
245 | ||
246 | return ok; | |
247 | } | |
248 | EXPORT_SYMBOL_GPL(crypto_probing_notify); | |
249 | ||
250 | struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask) | |
251 | { | |
252 | struct crypto_alg *alg; | |
253 | struct crypto_alg *larval; | |
254 | int ok; | |
255 | ||
256 | if (!((type | mask) & CRYPTO_ALG_TESTED)) { | |
257 | type |= CRYPTO_ALG_TESTED; | |
258 | mask |= CRYPTO_ALG_TESTED; | |
259 | } | |
260 | ||
261 | larval = crypto_larval_lookup(name, type, mask); | |
262 | if (IS_ERR(larval) || !crypto_is_larval(larval)) | |
263 | return larval; | |
264 | ||
265 | ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval); | |
266 | ||
267 | if (ok == NOTIFY_STOP) | |
268 | alg = crypto_larval_wait(larval); | |
269 | else { | |
270 | crypto_mod_put(larval); | |
271 | alg = ERR_PTR(-ENOENT); | |
272 | } | |
273 | crypto_larval_kill(larval); | |
274 | return alg; | |
275 | } | |
276 | EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup); | |
277 | ||
278 | static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask) | |
279 | { | |
280 | const struct crypto_type *type_obj = tfm->__crt_alg->cra_type; | |
281 | ||
282 | if (type_obj) | |
283 | return type_obj->init(tfm, type, mask); | |
284 | ||
285 | switch (crypto_tfm_alg_type(tfm)) { | |
286 | case CRYPTO_ALG_TYPE_CIPHER: | |
287 | return crypto_init_cipher_ops(tfm); | |
288 | ||
289 | case CRYPTO_ALG_TYPE_COMPRESS: | |
290 | return crypto_init_compress_ops(tfm); | |
291 | ||
292 | default: | |
293 | break; | |
294 | } | |
295 | ||
296 | BUG(); | |
297 | return -EINVAL; | |
298 | } | |
299 | ||
300 | static void crypto_exit_ops(struct crypto_tfm *tfm) | |
301 | { | |
302 | const struct crypto_type *type = tfm->__crt_alg->cra_type; | |
303 | ||
304 | if (type) { | |
305 | if (tfm->exit) | |
306 | tfm->exit(tfm); | |
307 | return; | |
308 | } | |
309 | ||
310 | switch (crypto_tfm_alg_type(tfm)) { | |
311 | case CRYPTO_ALG_TYPE_CIPHER: | |
312 | crypto_exit_cipher_ops(tfm); | |
313 | break; | |
314 | ||
315 | case CRYPTO_ALG_TYPE_COMPRESS: | |
316 | crypto_exit_compress_ops(tfm); | |
317 | break; | |
318 | ||
319 | default: | |
320 | BUG(); | |
321 | } | |
322 | } | |
323 | ||
324 | static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask) | |
325 | { | |
326 | const struct crypto_type *type_obj = alg->cra_type; | |
327 | unsigned int len; | |
328 | ||
329 | len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1); | |
330 | if (type_obj) | |
331 | return len + type_obj->ctxsize(alg, type, mask); | |
332 | ||
333 | switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) { | |
334 | default: | |
335 | BUG(); | |
336 | ||
337 | case CRYPTO_ALG_TYPE_CIPHER: | |
338 | len += crypto_cipher_ctxsize(alg); | |
339 | break; | |
340 | ||
341 | case CRYPTO_ALG_TYPE_COMPRESS: | |
342 | len += crypto_compress_ctxsize(alg); | |
343 | break; | |
344 | } | |
345 | ||
346 | return len; | |
347 | } | |
348 | ||
349 | void crypto_shoot_alg(struct crypto_alg *alg) | |
350 | { | |
351 | down_write(&crypto_alg_sem); | |
352 | alg->cra_flags |= CRYPTO_ALG_DYING; | |
353 | up_write(&crypto_alg_sem); | |
354 | } | |
355 | EXPORT_SYMBOL_GPL(crypto_shoot_alg); | |
356 | ||
357 | struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type, | |
358 | u32 mask) | |
359 | { | |
360 | struct crypto_tfm *tfm = NULL; | |
361 | unsigned int tfm_size; | |
362 | int err = -ENOMEM; | |
363 | ||
364 | tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask); | |
365 | tfm = kzalloc(tfm_size, GFP_KERNEL); | |
366 | if (tfm == NULL) | |
367 | goto out_err; | |
368 | ||
369 | tfm->__crt_alg = alg; | |
370 | ||
371 | err = crypto_init_ops(tfm, type, mask); | |
372 | if (err) | |
373 | goto out_free_tfm; | |
374 | ||
375 | if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm))) | |
376 | goto cra_init_failed; | |
377 | ||
378 | goto out; | |
379 | ||
380 | cra_init_failed: | |
381 | crypto_exit_ops(tfm); | |
382 | out_free_tfm: | |
383 | if (err == -EAGAIN) | |
384 | crypto_shoot_alg(alg); | |
385 | kfree(tfm); | |
386 | out_err: | |
387 | tfm = ERR_PTR(err); | |
388 | out: | |
389 | return tfm; | |
390 | } | |
391 | EXPORT_SYMBOL_GPL(__crypto_alloc_tfm); | |
392 | ||
393 | /* | |
394 | * crypto_alloc_base - Locate algorithm and allocate transform | |
395 | * @alg_name: Name of algorithm | |
396 | * @type: Type of algorithm | |
397 | * @mask: Mask for type comparison | |
398 | * | |
399 | * This function should not be used by new algorithm types. | |
400 | * Plesae use crypto_alloc_tfm instead. | |
401 | * | |
402 | * crypto_alloc_base() will first attempt to locate an already loaded | |
403 | * algorithm. If that fails and the kernel supports dynamically loadable | |
404 | * modules, it will then attempt to load a module of the same name or | |
405 | * alias. If that fails it will send a query to any loaded crypto manager | |
406 | * to construct an algorithm on the fly. A refcount is grabbed on the | |
407 | * algorithm which is then associated with the new transform. | |
408 | * | |
409 | * The returned transform is of a non-determinate type. Most people | |
410 | * should use one of the more specific allocation functions such as | |
411 | * crypto_alloc_blkcipher. | |
412 | * | |
413 | * In case of error the return value is an error pointer. | |
414 | */ | |
415 | struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask) | |
416 | { | |
417 | struct crypto_tfm *tfm; | |
418 | int err; | |
419 | ||
420 | for (;;) { | |
421 | struct crypto_alg *alg; | |
422 | ||
423 | alg = crypto_alg_mod_lookup(alg_name, type, mask); | |
424 | if (IS_ERR(alg)) { | |
425 | err = PTR_ERR(alg); | |
426 | goto err; | |
427 | } | |
428 | ||
429 | tfm = __crypto_alloc_tfm(alg, type, mask); | |
430 | if (!IS_ERR(tfm)) | |
431 | return tfm; | |
432 | ||
433 | crypto_mod_put(alg); | |
434 | err = PTR_ERR(tfm); | |
435 | ||
436 | err: | |
437 | if (err != -EAGAIN) | |
438 | break; | |
439 | if (signal_pending(current)) { | |
440 | err = -EINTR; | |
441 | break; | |
442 | } | |
443 | } | |
444 | ||
445 | return ERR_PTR(err); | |
446 | } | |
447 | EXPORT_SYMBOL_GPL(crypto_alloc_base); | |
448 | ||
449 | void *crypto_create_tfm(struct crypto_alg *alg, | |
450 | const struct crypto_type *frontend) | |
451 | { | |
452 | char *mem; | |
453 | struct crypto_tfm *tfm = NULL; | |
454 | unsigned int tfmsize; | |
455 | unsigned int total; | |
456 | int err = -ENOMEM; | |
457 | ||
458 | tfmsize = frontend->tfmsize; | |
459 | total = tfmsize + sizeof(*tfm) + frontend->extsize(alg); | |
460 | ||
461 | mem = kzalloc(total, GFP_KERNEL); | |
462 | if (mem == NULL) | |
463 | goto out_err; | |
464 | ||
465 | tfm = (struct crypto_tfm *)(mem + tfmsize); | |
466 | tfm->__crt_alg = alg; | |
467 | ||
468 | err = frontend->init_tfm(tfm); | |
469 | if (err) | |
470 | goto out_free_tfm; | |
471 | ||
472 | if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm))) | |
473 | goto cra_init_failed; | |
474 | ||
475 | goto out; | |
476 | ||
477 | cra_init_failed: | |
478 | crypto_exit_ops(tfm); | |
479 | out_free_tfm: | |
480 | if (err == -EAGAIN) | |
481 | crypto_shoot_alg(alg); | |
482 | kfree(mem); | |
483 | out_err: | |
484 | mem = ERR_PTR(err); | |
485 | out: | |
486 | return mem; | |
487 | } | |
488 | EXPORT_SYMBOL_GPL(crypto_create_tfm); | |
489 | ||
490 | struct crypto_alg *crypto_find_alg(const char *alg_name, | |
491 | const struct crypto_type *frontend, | |
492 | u32 type, u32 mask) | |
493 | { | |
494 | struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask) = | |
495 | crypto_alg_mod_lookup; | |
496 | ||
497 | if (frontend) { | |
498 | type &= frontend->maskclear; | |
499 | mask &= frontend->maskclear; | |
500 | type |= frontend->type; | |
501 | mask |= frontend->maskset; | |
502 | ||
503 | if (frontend->lookup) | |
504 | lookup = frontend->lookup; | |
505 | } | |
506 | ||
507 | return lookup(alg_name, type, mask); | |
508 | } | |
509 | EXPORT_SYMBOL_GPL(crypto_find_alg); | |
510 | ||
511 | /* | |
512 | * crypto_alloc_tfm - Locate algorithm and allocate transform | |
513 | * @alg_name: Name of algorithm | |
514 | * @frontend: Frontend algorithm type | |
515 | * @type: Type of algorithm | |
516 | * @mask: Mask for type comparison | |
517 | * | |
518 | * crypto_alloc_tfm() will first attempt to locate an already loaded | |
519 | * algorithm. If that fails and the kernel supports dynamically loadable | |
520 | * modules, it will then attempt to load a module of the same name or | |
521 | * alias. If that fails it will send a query to any loaded crypto manager | |
522 | * to construct an algorithm on the fly. A refcount is grabbed on the | |
523 | * algorithm which is then associated with the new transform. | |
524 | * | |
525 | * The returned transform is of a non-determinate type. Most people | |
526 | * should use one of the more specific allocation functions such as | |
527 | * crypto_alloc_blkcipher. | |
528 | * | |
529 | * In case of error the return value is an error pointer. | |
530 | */ | |
531 | void *crypto_alloc_tfm(const char *alg_name, | |
532 | const struct crypto_type *frontend, u32 type, u32 mask) | |
533 | { | |
534 | void *tfm; | |
535 | int err; | |
536 | ||
537 | for (;;) { | |
538 | struct crypto_alg *alg; | |
539 | ||
540 | alg = crypto_find_alg(alg_name, frontend, type, mask); | |
541 | if (IS_ERR(alg)) { | |
542 | err = PTR_ERR(alg); | |
543 | goto err; | |
544 | } | |
545 | ||
546 | tfm = crypto_create_tfm(alg, frontend); | |
547 | if (!IS_ERR(tfm)) | |
548 | return tfm; | |
549 | ||
550 | crypto_mod_put(alg); | |
551 | err = PTR_ERR(tfm); | |
552 | ||
553 | err: | |
554 | if (err != -EAGAIN) | |
555 | break; | |
556 | if (signal_pending(current)) { | |
557 | err = -EINTR; | |
558 | break; | |
559 | } | |
560 | } | |
561 | ||
562 | return ERR_PTR(err); | |
563 | } | |
564 | EXPORT_SYMBOL_GPL(crypto_alloc_tfm); | |
565 | ||
566 | /* | |
567 | * crypto_destroy_tfm - Free crypto transform | |
568 | * @mem: Start of tfm slab | |
569 | * @tfm: Transform to free | |
570 | * | |
571 | * This function frees up the transform and any associated resources, | |
572 | * then drops the refcount on the associated algorithm. | |
573 | */ | |
574 | void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm) | |
575 | { | |
576 | struct crypto_alg *alg; | |
577 | ||
578 | if (unlikely(!mem)) | |
579 | return; | |
580 | ||
581 | alg = tfm->__crt_alg; | |
582 | ||
583 | if (!tfm->exit && alg->cra_exit) | |
584 | alg->cra_exit(tfm); | |
585 | crypto_exit_ops(tfm); | |
586 | crypto_mod_put(alg); | |
587 | kzfree(mem); | |
588 | } | |
589 | EXPORT_SYMBOL_GPL(crypto_destroy_tfm); | |
590 | ||
591 | int crypto_has_alg(const char *name, u32 type, u32 mask) | |
592 | { | |
593 | int ret = 0; | |
594 | struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask); | |
595 | ||
596 | if (!IS_ERR(alg)) { | |
597 | crypto_mod_put(alg); | |
598 | ret = 1; | |
599 | } | |
600 | ||
601 | return ret; | |
602 | } | |
603 | EXPORT_SYMBOL_GPL(crypto_has_alg); | |
604 | ||
605 | MODULE_DESCRIPTION("Cryptographic core API"); | |
606 | MODULE_LICENSE("GPL"); |