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[mirror_ubuntu-bionic-kernel.git] / crypto / api.c
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
77dbd7a9
HX
37static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
38
2825982d 39struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
6521f302
HX
40{
41 return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
1da177e4 42}
2825982d 43EXPORT_SYMBOL_GPL(crypto_mod_get);
1da177e4 44
2825982d 45void crypto_mod_put(struct crypto_alg *alg)
1da177e4 46{
da7cd59a
HX
47 struct module *module = alg->cra_module;
48
6521f302 49 crypto_alg_put(alg);
da7cd59a 50 module_put(module);
1da177e4 51}
2825982d 52EXPORT_SYMBOL_GPL(crypto_mod_put);
1da177e4 53
73d3864a
HX
54static inline int crypto_is_test_larval(struct crypto_larval *larval)
55{
56 return larval->alg.cra_driver_name[0];
57}
58
c51b6c81
HX
59static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
60 u32 mask)
1da177e4
LT
61{
62 struct crypto_alg *q, *alg = NULL;
2825982d 63 int best = -2;
1da177e4 64
1da177e4 65 list_for_each_entry(q, &crypto_alg_list, cra_list) {
5cb1454b
HX
66 int exact, fuzzy;
67
6bfd4809
HX
68 if (crypto_is_moribund(q))
69 continue;
70
492e2b63
HX
71 if ((q->cra_flags ^ type) & mask)
72 continue;
73
74 if (crypto_is_larval(q) &&
73d3864a 75 !crypto_is_test_larval((struct crypto_larval *)q) &&
492e2b63
HX
76 ((struct crypto_larval *)q)->mask != mask)
77 continue;
78
5cb1454b
HX
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
72fa4919 84 if (unlikely(!crypto_mod_get(q)))
5cb1454b
HX
85 continue;
86
87 best = q->cra_priority;
88 if (alg)
72fa4919 89 crypto_mod_put(alg);
5cb1454b
HX
90 alg = q;
91
92 if (exact)
1da177e4 93 break;
1da177e4 94 }
2825982d
HX
95
96 return alg;
97}
2825982d
HX
98
99static 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
73d3864a 109struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
2825982d 110{
2825982d
HX
111 struct crypto_larval *larval;
112
113 larval = kzalloc(sizeof(*larval), GFP_KERNEL);
114 if (!larval)
6bfd4809 115 return ERR_PTR(-ENOMEM);
2825982d 116
492e2b63
HX
117 larval->mask = mask;
118 larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
2825982d
HX
119 larval->alg.cra_priority = -1;
120 larval->alg.cra_destroy = crypto_larval_destroy;
121
2825982d
HX
122 strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
123 init_completion(&larval->completion);
124
73d3864a
HX
125 return larval;
126}
127EXPORT_SYMBOL_GPL(crypto_larval_alloc);
128
129static 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
2825982d 141 down_write(&crypto_alg_sem);
492e2b63 142 alg = __crypto_alg_lookup(name, type, mask);
2825982d
HX
143 if (!alg) {
144 alg = &larval->alg;
145 list_add(&alg->cra_list, &crypto_alg_list);
146 }
147 up_write(&crypto_alg_sem);
148
77dbd7a9 149 if (alg != &larval->alg) {
2825982d 150 kfree(larval);
77dbd7a9
HX
151 if (crypto_is_larval(alg))
152 alg = crypto_larval_wait(alg);
153 }
2825982d
HX
154
155 return alg;
156}
157
b9c55aa4 158void crypto_larval_kill(struct crypto_alg *alg)
2825982d
HX
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);
fe3c5206 165 complete_all(&larval->completion);
2825982d
HX
166 crypto_alg_put(alg);
167}
b9c55aa4 168EXPORT_SYMBOL_GPL(crypto_larval_kill);
2825982d
HX
169
170static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
171{
172 struct crypto_larval *larval = (void *)alg;
73d3864a
HX
173 long timeout;
174
175 timeout = wait_for_completion_interruptible_timeout(
176 &larval->completion, 60 * HZ);
2825982d 177
2825982d 178 alg = larval->adult;
73d3864a
HX
179 if (timeout < 0)
180 alg = ERR_PTR(-EINTR);
181 else if (!timeout)
182 alg = ERR_PTR(-ETIMEDOUT);
183 else if (!alg)
6bfd4809 184 alg = ERR_PTR(-ENOENT);
73d3864a
HX
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);
2825982d
HX
190 crypto_mod_put(&larval->alg);
191
192 return alg;
193}
194
c51b6c81 195struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, u32 mask)
2825982d
HX
196{
197 struct crypto_alg *alg;
198
2825982d 199 down_read(&crypto_alg_sem);
492e2b63 200 alg = __crypto_alg_lookup(name, type, mask);
1da177e4 201 up_read(&crypto_alg_sem);
2825982d 202
1da177e4
LT
203 return alg;
204}
c51b6c81 205EXPORT_SYMBOL_GPL(crypto_alg_lookup);
1da177e4 206
b9c55aa4 207struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask)
176c3652 208{
2825982d 209 struct crypto_alg *alg;
2825982d 210
6bfd4809
HX
211 if (!name)
212 return ERR_PTR(-ENOENT);
213
214 mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
492e2b63
HX
215 type &= mask;
216
a760a665
HX
217 alg = crypto_alg_lookup(name, type, mask);
218 if (!alg) {
aa07a699 219 request_module("%s", name);
a760a665 220
37fc334c 221 if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
aa07a699
AR
222 CRYPTO_ALG_NEED_FALLBACK))
223 request_module("%s-all", name);
a760a665
HX
224
225 alg = crypto_alg_lookup(name, type, mask);
226 }
227
2825982d
HX
228 if (alg)
229 return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
230
73d3864a 231 return crypto_larval_add(name, type, mask);
b9c55aa4
HX
232}
233EXPORT_SYMBOL_GPL(crypto_larval_lookup);
234
73d3864a
HX
235int 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}
247EXPORT_SYMBOL_GPL(crypto_probing_notify);
248
b9c55aa4
HX
249struct 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
ff753308 255 if (!((type | mask) & CRYPTO_ALG_TESTED)) {
73d3864a
HX
256 type |= CRYPTO_ALG_TESTED;
257 mask |= CRYPTO_ALG_TESTED;
258 }
259
b9c55aa4 260 larval = crypto_larval_lookup(name, type, mask);
6bfd4809 261 if (IS_ERR(larval) || !crypto_is_larval(larval))
2825982d
HX
262 return larval;
263
73d3864a 264 ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
2b8c19db
HX
265
266 if (ok == NOTIFY_STOP)
2825982d
HX
267 alg = crypto_larval_wait(larval);
268 else {
269 crypto_mod_put(larval);
6bfd4809 270 alg = ERR_PTR(-ENOENT);
2825982d
HX
271 }
272 crypto_larval_kill(larval);
273 return alg;
176c3652 274}
492e2b63 275EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
176c3652 276
27d2a330 277static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
1da177e4 278{
27d2a330 279 const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
e853c3cf 280
27d2a330
HX
281 if (type_obj)
282 return type_obj->init(tfm, type, mask);
e853c3cf 283
1da177e4
LT
284 switch (crypto_tfm_alg_type(tfm)) {
285 case CRYPTO_ALG_TYPE_CIPHER:
286 return crypto_init_cipher_ops(tfm);
004a403c 287
1da177e4
LT
288 case CRYPTO_ALG_TYPE_COMPRESS:
289 return crypto_init_compress_ops(tfm);
3d01a33b 290
1da177e4
LT
291 default:
292 break;
293 }
3d01a33b 294
1da177e4
LT
295 BUG();
296 return -EINVAL;
297}
298
299static void crypto_exit_ops(struct crypto_tfm *tfm)
300{
e853c3cf
HX
301 const struct crypto_type *type = tfm->__crt_alg->cra_type;
302
303 if (type) {
4a779486
HX
304 if (tfm->exit)
305 tfm->exit(tfm);
e853c3cf
HX
306 return;
307 }
308
1da177e4
LT
309 switch (crypto_tfm_alg_type(tfm)) {
310 case CRYPTO_ALG_TYPE_CIPHER:
311 crypto_exit_cipher_ops(tfm);
312 break;
6941c3a0 313
1da177e4
LT
314 case CRYPTO_ALG_TYPE_COMPRESS:
315 crypto_exit_compress_ops(tfm);
316 break;
3d01a33b 317
1da177e4
LT
318 default:
319 BUG();
1da177e4
LT
320 }
321}
322
27d2a330 323static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
fbdae9f3 324{
27d2a330 325 const struct crypto_type *type_obj = alg->cra_type;
fbdae9f3
HX
326 unsigned int len;
327
e853c3cf 328 len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
27d2a330
HX
329 if (type_obj)
330 return len + type_obj->ctxsize(alg, type, mask);
e853c3cf 331
fbdae9f3
HX
332 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
333 default:
334 BUG();
335
336 case CRYPTO_ALG_TYPE_CIPHER:
f1ddcaf3 337 len += crypto_cipher_ctxsize(alg);
fbdae9f3 338 break;
6941c3a0 339
fbdae9f3 340 case CRYPTO_ALG_TYPE_COMPRESS:
f1ddcaf3 341 len += crypto_compress_ctxsize(alg);
fbdae9f3
HX
342 break;
343 }
344
e853c3cf 345 return len;
fbdae9f3
HX
346}
347
6bfd4809
HX
348void 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}
354EXPORT_SYMBOL_GPL(crypto_shoot_alg);
355
27d2a330
HX
356struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
357 u32 mask)
1da177e4
LT
358{
359 struct crypto_tfm *tfm = NULL;
fbdae9f3 360 unsigned int tfm_size;
6bfd4809 361 int err = -ENOMEM;
fbdae9f3 362
27d2a330 363 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
bbeb563f 364 tfm = kzalloc(tfm_size, GFP_KERNEL);
1da177e4 365 if (tfm == NULL)
9765d262 366 goto out_err;
1da177e4 367
1da177e4 368 tfm->__crt_alg = alg;
6bfd4809 369
27d2a330 370 err = crypto_init_ops(tfm, type, mask);
6bfd4809 371 if (err)
1da177e4 372 goto out_free_tfm;
c7fc0599 373
4a779486 374 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
c7fc0599 375 goto cra_init_failed;
1da177e4
LT
376
377 goto out;
378
c7fc0599
HX
379cra_init_failed:
380 crypto_exit_ops(tfm);
1da177e4 381out_free_tfm:
4a779486
HX
382 if (err == -EAGAIN)
383 crypto_shoot_alg(alg);
1da177e4 384 kfree(tfm);
9765d262 385out_err:
6bfd4809 386 tfm = ERR_PTR(err);
1da177e4
LT
387out:
388 return tfm;
389}
6bfd4809
HX
390EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
391
6d7d684d
HX
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 *
7b0bac64 398 * This function should not be used by new algorithm types.
fd1a1900 399 * Please use crypto_alloc_tfm instead.
7b0bac64 400 *
6d7d684d
HX
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 */
414struct 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);
9765d262
AM
423 if (IS_ERR(alg)) {
424 err = PTR_ERR(alg);
6d7d684d 425 goto err;
9765d262 426 }
6d7d684d 427
27d2a330 428 tfm = __crypto_alloc_tfm(alg, type, mask);
6d7d684d 429 if (!IS_ERR(tfm))
9765d262 430 return tfm;
6d7d684d
HX
431
432 crypto_mod_put(alg);
433 err = PTR_ERR(tfm);
434
435err:
436 if (err != -EAGAIN)
437 break;
438 if (signal_pending(current)) {
439 err = -EINTR;
440 break;
441 }
9765d262 442 }
6d7d684d 443
9765d262 444 return ERR_PTR(err);
6d7d684d
HX
445}
446EXPORT_SYMBOL_GPL(crypto_alloc_base);
7b0bac64 447
3f683d61
HX
448void *crypto_create_tfm(struct crypto_alg *alg,
449 const struct crypto_type *frontend)
7b0bac64
HX
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;
2ca33da1 458 total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
7b0bac64
HX
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
2ca33da1 467 err = frontend->init_tfm(tfm);
7b0bac64
HX
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
476cra_init_failed:
477 crypto_exit_ops(tfm);
478out_free_tfm:
479 if (err == -EAGAIN)
480 crypto_shoot_alg(alg);
481 kfree(mem);
482out_err:
3f683d61 483 mem = ERR_PTR(err);
7b0bac64 484out:
3f683d61 485 return mem;
7b0bac64
HX
486}
487EXPORT_SYMBOL_GPL(crypto_create_tfm);
488
d06854f0
HX
489struct 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}
508EXPORT_SYMBOL_GPL(crypto_find_alg);
509
7b0bac64
HX
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 */
3f683d61
HX
530void *crypto_alloc_tfm(const char *alg_name,
531 const struct crypto_type *frontend, u32 type, u32 mask)
7b0bac64 532{
3f683d61 533 void *tfm;
7b0bac64
HX
534 int err;
535
7b0bac64
HX
536 for (;;) {
537 struct crypto_alg *alg;
538
d06854f0 539 alg = crypto_find_alg(alg_name, frontend, type, mask);
7b0bac64
HX
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
552err:
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}
563EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
7b2cd92a 564
6d7d684d 565/*
7b2cd92a
HX
566 * crypto_destroy_tfm - Free crypto transform
567 * @mem: Start of tfm slab
6d7d684d
HX
568 * @tfm: Transform to free
569 *
7b2cd92a 570 * This function frees up the transform and any associated resources,
6d7d684d
HX
571 * then drops the refcount on the associated algorithm.
572 */
7b2cd92a 573void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
1da177e4 574{
a61cc448 575 struct crypto_alg *alg;
a61cc448 576
7b2cd92a 577 if (unlikely(!mem))
a61cc448
JJ
578 return;
579
580 alg = tfm->__crt_alg;
1da177e4 581
4a779486 582 if (!tfm->exit && alg->cra_exit)
c7fc0599 583 alg->cra_exit(tfm);
1da177e4 584 crypto_exit_ops(tfm);
72fa4919 585 crypto_mod_put(alg);
811d8f06 586 kzfree(mem);
1da177e4 587}
7b2cd92a 588EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
fce32d70
HX
589
590int 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);
3d01a33b 594
fce32d70
HX
595 if (!IS_ERR(alg)) {
596 crypto_mod_put(alg);
597 ret = 1;
598 }
3d01a33b 599
fce32d70
HX
600 return ret;
601}
602EXPORT_SYMBOL_GPL(crypto_has_alg);
c3715cb9
SS
603
604MODULE_DESCRIPTION("Cryptographic core API");
605MODULE_LICENSE("GPL");