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