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CommitLineData
1da177e4
LT
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)
5cb1454b 6 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
1da177e4
LT
7 *
8 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
991d1740 9 * and Nettle, by Niels Möller.
1da177e4
LT
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
3d01a33b 13 * Software Foundation; either version 2 of the License, or (at your option)
1da177e4
LT
14 * any later version.
15 *
16 */
a61cc448 17
6bfd4809 18#include <linux/err.h>
1da177e4 19#include <linux/errno.h>
5cb1454b 20#include <linux/kernel.h>
176c3652 21#include <linux/kmod.h>
2b8c19db 22#include <linux/module.h>
2825982d 23#include <linux/param.h>
6bfd4809 24#include <linux/sched.h>
1da177e4 25#include <linux/slab.h>
5cb1454b 26#include <linux/string.h>
1da177e4
LT
27#include "internal.h"
28
29LIST_HEAD(crypto_alg_list);
cce9e06d 30EXPORT_SYMBOL_GPL(crypto_alg_list);
1da177e4 31DECLARE_RWSEM(crypto_alg_sem);
cce9e06d 32EXPORT_SYMBOL_GPL(crypto_alg_sem);
1da177e4 33
2825982d
HX
34BLOCKING_NOTIFIER_HEAD(crypto_chain);
35EXPORT_SYMBOL_GPL(crypto_chain);
36
6521f302 37static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
1da177e4 38{
6521f302
HX
39 atomic_inc(&alg->cra_refcnt);
40 return alg;
41}
42
2825982d 43struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
6521f302
HX
44{
45 return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
1da177e4 46}
2825982d 47EXPORT_SYMBOL_GPL(crypto_mod_get);
1da177e4 48
2825982d 49void crypto_mod_put(struct crypto_alg *alg)
1da177e4 50{
da7cd59a
HX
51 struct module *module = alg->cra_module;
52
6521f302 53 crypto_alg_put(alg);
da7cd59a 54 module_put(module);
1da177e4 55}
2825982d 56EXPORT_SYMBOL_GPL(crypto_mod_put);
1da177e4 57
73d3864a
HX
58static inline int crypto_is_test_larval(struct crypto_larval *larval)
59{
60 return larval->alg.cra_driver_name[0];
61}
62
c51b6c81
HX
63static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
64 u32 mask)
1da177e4
LT
65{
66 struct crypto_alg *q, *alg = NULL;
2825982d 67 int best = -2;
1da177e4 68
1da177e4 69 list_for_each_entry(q, &crypto_alg_list, cra_list) {
5cb1454b
HX
70 int exact, fuzzy;
71
6bfd4809
HX
72 if (crypto_is_moribund(q))
73 continue;
74
492e2b63
HX
75 if ((q->cra_flags ^ type) & mask)
76 continue;
77
78 if (crypto_is_larval(q) &&
73d3864a 79 !crypto_is_test_larval((struct crypto_larval *)q) &&
492e2b63
HX
80 ((struct crypto_larval *)q)->mask != mask)
81 continue;
82
5cb1454b
HX
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
72fa4919 88 if (unlikely(!crypto_mod_get(q)))
5cb1454b
HX
89 continue;
90
91 best = q->cra_priority;
92 if (alg)
72fa4919 93 crypto_mod_put(alg);
5cb1454b
HX
94 alg = q;
95
96 if (exact)
1da177e4 97 break;
1da177e4 98 }
2825982d
HX
99
100 return alg;
101}
2825982d
HX
102
103static 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
73d3864a 113struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
2825982d 114{
2825982d
HX
115 struct crypto_larval *larval;
116
117 larval = kzalloc(sizeof(*larval), GFP_KERNEL);
118 if (!larval)
6bfd4809 119 return ERR_PTR(-ENOMEM);
2825982d 120
492e2b63
HX
121 larval->mask = mask;
122 larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
2825982d
HX
123 larval->alg.cra_priority = -1;
124 larval->alg.cra_destroy = crypto_larval_destroy;
125
2825982d
HX
126 strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
127 init_completion(&larval->completion);
128
73d3864a
HX
129 return larval;
130}
131EXPORT_SYMBOL_GPL(crypto_larval_alloc);
132
133static 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
2825982d 145 down_write(&crypto_alg_sem);
492e2b63 146 alg = __crypto_alg_lookup(name, type, mask);
2825982d
HX
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
b9c55aa4 159void crypto_larval_kill(struct crypto_alg *alg)
2825982d
HX
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);
fe3c5206 166 complete_all(&larval->completion);
2825982d
HX
167 crypto_alg_put(alg);
168}
b9c55aa4 169EXPORT_SYMBOL_GPL(crypto_larval_kill);
2825982d
HX
170
171static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
172{
173 struct crypto_larval *larval = (void *)alg;
73d3864a
HX
174 long timeout;
175
176 timeout = wait_for_completion_interruptible_timeout(
177 &larval->completion, 60 * HZ);
2825982d 178
2825982d 179 alg = larval->adult;
73d3864a
HX
180 if (timeout < 0)
181 alg = ERR_PTR(-EINTR);
182 else if (!timeout)
183 alg = ERR_PTR(-ETIMEDOUT);
184 else if (!alg)
6bfd4809 185 alg = ERR_PTR(-ENOENT);
73d3864a
HX
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);
2825982d
HX
191 crypto_mod_put(&larval->alg);
192
193 return alg;
194}
195
c51b6c81 196struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, u32 mask)
2825982d
HX
197{
198 struct crypto_alg *alg;
199
2825982d 200 down_read(&crypto_alg_sem);
492e2b63 201 alg = __crypto_alg_lookup(name, type, mask);
1da177e4 202 up_read(&crypto_alg_sem);
2825982d 203
1da177e4
LT
204 return alg;
205}
c51b6c81 206EXPORT_SYMBOL_GPL(crypto_alg_lookup);
1da177e4 207
b9c55aa4 208struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask)
176c3652 209{
2825982d 210 struct crypto_alg *alg;
2825982d 211
6bfd4809
HX
212 if (!name)
213 return ERR_PTR(-ENOENT);
214
215 mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
492e2b63
HX
216 type &= mask;
217
a760a665
HX
218 alg = crypto_alg_lookup(name, type, mask);
219 if (!alg) {
aa07a699 220 request_module("%s", name);
a760a665 221
37fc334c 222 if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
aa07a699
AR
223 CRYPTO_ALG_NEED_FALLBACK))
224 request_module("%s-all", name);
a760a665
HX
225
226 alg = crypto_alg_lookup(name, type, mask);
227 }
228
2825982d
HX
229 if (alg)
230 return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
231
73d3864a 232 return crypto_larval_add(name, type, mask);
b9c55aa4
HX
233}
234EXPORT_SYMBOL_GPL(crypto_larval_lookup);
235
73d3864a
HX
236int 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}
248EXPORT_SYMBOL_GPL(crypto_probing_notify);
249
b9c55aa4
HX
250struct 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
ff753308 256 if (!((type | mask) & CRYPTO_ALG_TESTED)) {
73d3864a
HX
257 type |= CRYPTO_ALG_TESTED;
258 mask |= CRYPTO_ALG_TESTED;
259 }
260
b9c55aa4 261 larval = crypto_larval_lookup(name, type, mask);
6bfd4809 262 if (IS_ERR(larval) || !crypto_is_larval(larval))
2825982d
HX
263 return larval;
264
73d3864a 265 ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
2b8c19db
HX
266
267 if (ok == NOTIFY_STOP)
2825982d
HX
268 alg = crypto_larval_wait(larval);
269 else {
270 crypto_mod_put(larval);
6bfd4809 271 alg = ERR_PTR(-ENOENT);
2825982d
HX
272 }
273 crypto_larval_kill(larval);
274 return alg;
176c3652 275}
492e2b63 276EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
176c3652 277
27d2a330 278static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
1da177e4 279{
27d2a330 280 const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
e853c3cf 281
27d2a330
HX
282 if (type_obj)
283 return type_obj->init(tfm, type, mask);
e853c3cf 284
1da177e4
LT
285 switch (crypto_tfm_alg_type(tfm)) {
286 case CRYPTO_ALG_TYPE_CIPHER:
287 return crypto_init_cipher_ops(tfm);
004a403c 288
1da177e4
LT
289 case CRYPTO_ALG_TYPE_COMPRESS:
290 return crypto_init_compress_ops(tfm);
3d01a33b 291
1da177e4
LT
292 default:
293 break;
294 }
3d01a33b 295
1da177e4
LT
296 BUG();
297 return -EINVAL;
298}
299
300static void crypto_exit_ops(struct crypto_tfm *tfm)
301{
e853c3cf
HX
302 const struct crypto_type *type = tfm->__crt_alg->cra_type;
303
304 if (type) {
4a779486
HX
305 if (tfm->exit)
306 tfm->exit(tfm);
e853c3cf
HX
307 return;
308 }
309
1da177e4
LT
310 switch (crypto_tfm_alg_type(tfm)) {
311 case CRYPTO_ALG_TYPE_CIPHER:
312 crypto_exit_cipher_ops(tfm);
313 break;
6941c3a0 314
1da177e4
LT
315 case CRYPTO_ALG_TYPE_COMPRESS:
316 crypto_exit_compress_ops(tfm);
317 break;
3d01a33b 318
1da177e4
LT
319 default:
320 BUG();
1da177e4
LT
321 }
322}
323
27d2a330 324static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
fbdae9f3 325{
27d2a330 326 const struct crypto_type *type_obj = alg->cra_type;
fbdae9f3
HX
327 unsigned int len;
328
e853c3cf 329 len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
27d2a330
HX
330 if (type_obj)
331 return len + type_obj->ctxsize(alg, type, mask);
e853c3cf 332
fbdae9f3
HX
333 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
334 default:
335 BUG();
336
337 case CRYPTO_ALG_TYPE_CIPHER:
f1ddcaf3 338 len += crypto_cipher_ctxsize(alg);
fbdae9f3 339 break;
6941c3a0 340
fbdae9f3 341 case CRYPTO_ALG_TYPE_COMPRESS:
f1ddcaf3 342 len += crypto_compress_ctxsize(alg);
fbdae9f3
HX
343 break;
344 }
345
e853c3cf 346 return len;
fbdae9f3
HX
347}
348
6bfd4809
HX
349void 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}
355EXPORT_SYMBOL_GPL(crypto_shoot_alg);
356
27d2a330
HX
357struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
358 u32 mask)
1da177e4
LT
359{
360 struct crypto_tfm *tfm = NULL;
fbdae9f3 361 unsigned int tfm_size;
6bfd4809 362 int err = -ENOMEM;
fbdae9f3 363
27d2a330 364 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
bbeb563f 365 tfm = kzalloc(tfm_size, GFP_KERNEL);
1da177e4 366 if (tfm == NULL)
9765d262 367 goto out_err;
1da177e4 368
1da177e4 369 tfm->__crt_alg = alg;
6bfd4809 370
27d2a330 371 err = crypto_init_ops(tfm, type, mask);
6bfd4809 372 if (err)
1da177e4 373 goto out_free_tfm;
c7fc0599 374
4a779486 375 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
c7fc0599 376 goto cra_init_failed;
1da177e4
LT
377
378 goto out;
379
c7fc0599
HX
380cra_init_failed:
381 crypto_exit_ops(tfm);
1da177e4 382out_free_tfm:
4a779486
HX
383 if (err == -EAGAIN)
384 crypto_shoot_alg(alg);
1da177e4 385 kfree(tfm);
9765d262 386out_err:
6bfd4809 387 tfm = ERR_PTR(err);
1da177e4
LT
388out:
389 return tfm;
390}
6bfd4809
HX
391EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
392
6d7d684d
HX
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 *
7b0bac64
HX
399 * This function should not be used by new algorithm types.
400 * Plesae use crypto_alloc_tfm instead.
401 *
6d7d684d
HX
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 */
415struct 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);
9765d262
AM
424 if (IS_ERR(alg)) {
425 err = PTR_ERR(alg);
6d7d684d 426 goto err;
9765d262 427 }
6d7d684d 428
27d2a330 429 tfm = __crypto_alloc_tfm(alg, type, mask);
6d7d684d 430 if (!IS_ERR(tfm))
9765d262 431 return tfm;
6d7d684d
HX
432
433 crypto_mod_put(alg);
434 err = PTR_ERR(tfm);
435
436err:
437 if (err != -EAGAIN)
438 break;
439 if (signal_pending(current)) {
440 err = -EINTR;
441 break;
442 }
9765d262 443 }
6d7d684d 444
9765d262 445 return ERR_PTR(err);
6d7d684d
HX
446}
447EXPORT_SYMBOL_GPL(crypto_alloc_base);
7b0bac64 448
3f683d61
HX
449void *crypto_create_tfm(struct crypto_alg *alg,
450 const struct crypto_type *frontend)
7b0bac64
HX
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;
2ca33da1 459 total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
7b0bac64
HX
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
2ca33da1 468 err = frontend->init_tfm(tfm);
7b0bac64
HX
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
477cra_init_failed:
478 crypto_exit_ops(tfm);
479out_free_tfm:
480 if (err == -EAGAIN)
481 crypto_shoot_alg(alg);
482 kfree(mem);
483out_err:
3f683d61 484 mem = ERR_PTR(err);
7b0bac64 485out:
3f683d61 486 return mem;
7b0bac64
HX
487}
488EXPORT_SYMBOL_GPL(crypto_create_tfm);
489
d06854f0
HX
490struct 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}
509EXPORT_SYMBOL_GPL(crypto_find_alg);
510
7b0bac64
HX
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 */
3f683d61
HX
531void *crypto_alloc_tfm(const char *alg_name,
532 const struct crypto_type *frontend, u32 type, u32 mask)
7b0bac64 533{
3f683d61 534 void *tfm;
7b0bac64
HX
535 int err;
536
7b0bac64
HX
537 for (;;) {
538 struct crypto_alg *alg;
539
d06854f0 540 alg = crypto_find_alg(alg_name, frontend, type, mask);
7b0bac64
HX
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
553err:
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}
564EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
7b2cd92a 565
6d7d684d 566/*
7b2cd92a
HX
567 * crypto_destroy_tfm - Free crypto transform
568 * @mem: Start of tfm slab
6d7d684d
HX
569 * @tfm: Transform to free
570 *
7b2cd92a 571 * This function frees up the transform and any associated resources,
6d7d684d
HX
572 * then drops the refcount on the associated algorithm.
573 */
7b2cd92a 574void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
1da177e4 575{
a61cc448 576 struct crypto_alg *alg;
a61cc448 577
7b2cd92a 578 if (unlikely(!mem))
a61cc448
JJ
579 return;
580
581 alg = tfm->__crt_alg;
1da177e4 582
4a779486 583 if (!tfm->exit && alg->cra_exit)
c7fc0599 584 alg->cra_exit(tfm);
1da177e4 585 crypto_exit_ops(tfm);
72fa4919 586 crypto_mod_put(alg);
811d8f06 587 kzfree(mem);
1da177e4 588}
7b2cd92a 589EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
fce32d70
HX
590
591int 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);
3d01a33b 595
fce32d70
HX
596 if (!IS_ERR(alg)) {
597 crypto_mod_put(alg);
598 ret = 1;
599 }
3d01a33b 600
fce32d70
HX
601 return ret;
602}
603EXPORT_SYMBOL_GPL(crypto_has_alg);
c3715cb9
SS
604
605MODULE_DESCRIPTION("Cryptographic core API");
606MODULE_LICENSE("GPL");