1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ESSIV skcipher and aead template for block encryption
4 *
5 * This template encapsulates the ESSIV IV generation algorithm used by
6 * dm-crypt and fscrypt, which converts the initial vector for the skcipher
7 * used for block encryption, by encrypting it using the hash of the
8 * skcipher key as encryption key. Usually, the input IV is a 64-bit sector
9 * number in LE representation zero-padded to the size of the IV, but this
10 * is not assumed by this driver.
11 *
12 * The typical use of this template is to instantiate the skcipher
13 * 'essiv(cbc(aes),sha256)', which is the only instantiation used by
14 * fscrypt, and the most relevant one for dm-crypt. However, dm-crypt
15 * also permits ESSIV to be used in combination with the authenc template,
16 * e.g., 'essiv(authenc(hmac(sha256),cbc(aes)),sha256)', in which case
17 * we need to instantiate an aead that accepts the same special key format
18 * as the authenc template, and deals with the way the encrypted IV is
19 * embedded into the AAD area of the aead request. This means the AEAD
20 * flavor produced by this template is tightly coupled to the way dm-crypt
21 * happens to use it.
22 *
23 * Copyright (c) 2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
24 *
25 * Heavily based on:
26 * adiantum length-preserving encryption mode
27 *
28 * Copyright 2018 Google LLC
29 */
30
31#include <crypto/authenc.h>
32#include <crypto/internal/aead.h>
33#include <crypto/internal/cipher.h>
34#include <crypto/internal/hash.h>
35#include <crypto/internal/skcipher.h>
36#include <crypto/scatterwalk.h>
37#include <linux/module.h>
38
39#include "internal.h"
40
41struct essiv_instance_ctx {
42 union {
43 struct crypto_skcipher_spawn skcipher_spawn;
44 struct crypto_aead_spawn aead_spawn;
45 } u;
46 char essiv_cipher_name[CRYPTO_MAX_ALG_NAME];
47 char shash_driver_name[CRYPTO_MAX_ALG_NAME];
48};
49
50struct essiv_tfm_ctx {
51 union {
52 struct crypto_skcipher *skcipher;
53 struct crypto_aead *aead;
54 } u;
55 struct crypto_cipher *essiv_cipher;
56 struct crypto_shash *hash;
57 int ivoffset;
58};
59
60struct essiv_aead_request_ctx {
61 struct scatterlist sg[4];
62 u8 *assoc;
63 struct aead_request aead_req;
64};
65
66static int essiv_skcipher_setkey(struct crypto_skcipher *tfm,
67 const u8 *key, unsigned int keylen)
68{
69 struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
70 u8 salt[HASH_MAX_DIGESTSIZE];
71 int err;
72
73 crypto_skcipher_clear_flags(tfm: tctx->u.skcipher, CRYPTO_TFM_REQ_MASK);
74 crypto_skcipher_set_flags(tfm: tctx->u.skcipher,
75 flags: crypto_skcipher_get_flags(tfm) &
76 CRYPTO_TFM_REQ_MASK);
77 err = crypto_skcipher_setkey(tfm: tctx->u.skcipher, key, keylen);
78 if (err)
79 return err;
80
81 err = crypto_shash_tfm_digest(tfm: tctx->hash, data: key, len: keylen, out: salt);
82 if (err)
83 return err;
84
85 crypto_cipher_clear_flags(tfm: tctx->essiv_cipher, CRYPTO_TFM_REQ_MASK);
86 crypto_cipher_set_flags(tfm: tctx->essiv_cipher,
87 flags: crypto_skcipher_get_flags(tfm) &
88 CRYPTO_TFM_REQ_MASK);
89 return crypto_cipher_setkey(tfm: tctx->essiv_cipher, key: salt,
90 keylen: crypto_shash_digestsize(tfm: tctx->hash));
91}
92
93static int essiv_aead_setkey(struct crypto_aead *tfm, const u8 *key,
94 unsigned int keylen)
95{
96 struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
97 SHASH_DESC_ON_STACK(desc, tctx->hash);
98 struct crypto_authenc_keys keys;
99 u8 salt[HASH_MAX_DIGESTSIZE];
100 int err;
101
102 crypto_aead_clear_flags(tfm: tctx->u.aead, CRYPTO_TFM_REQ_MASK);
103 crypto_aead_set_flags(tfm: tctx->u.aead, flags: crypto_aead_get_flags(tfm) &
104 CRYPTO_TFM_REQ_MASK);
105 err = crypto_aead_setkey(tfm: tctx->u.aead, key, keylen);
106 if (err)
107 return err;
108
109 if (crypto_authenc_extractkeys(keys: &keys, key, keylen) != 0)
110 return -EINVAL;
111
112 desc->tfm = tctx->hash;
113 err = crypto_shash_init(desc) ?:
114 crypto_shash_update(desc, data: keys.enckey, len: keys.enckeylen) ?:
115 crypto_shash_finup(desc, data: keys.authkey, len: keys.authkeylen, out: salt);
116 if (err)
117 return err;
118
119 crypto_cipher_clear_flags(tfm: tctx->essiv_cipher, CRYPTO_TFM_REQ_MASK);
120 crypto_cipher_set_flags(tfm: tctx->essiv_cipher, flags: crypto_aead_get_flags(tfm) &
121 CRYPTO_TFM_REQ_MASK);
122 return crypto_cipher_setkey(tfm: tctx->essiv_cipher, key: salt,
123 keylen: crypto_shash_digestsize(tfm: tctx->hash));
124}
125
126static int essiv_aead_setauthsize(struct crypto_aead *tfm,
127 unsigned int authsize)
128{
129 struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
130
131 return crypto_aead_setauthsize(tfm: tctx->u.aead, authsize);
132}
133
134static void essiv_skcipher_done(void *data, int err)
135{
136 struct skcipher_request *req = data;
137
138 skcipher_request_complete(req, err);
139}
140
141static int essiv_skcipher_crypt(struct skcipher_request *req, bool enc)
142{
143 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
144 const struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
145 struct skcipher_request *subreq = skcipher_request_ctx(req);
146
147 crypto_cipher_encrypt_one(tfm: tctx->essiv_cipher, dst: req->iv, src: req->iv);
148
149 skcipher_request_set_tfm(req: subreq, tfm: tctx->u.skcipher);
150 skcipher_request_set_crypt(req: subreq, src: req->src, dst: req->dst, cryptlen: req->cryptlen,
151 iv: req->iv);
152 skcipher_request_set_callback(req: subreq, flags: skcipher_request_flags(req),
153 compl: essiv_skcipher_done, data: req);
154
155 return enc ? crypto_skcipher_encrypt(req: subreq) :
156 crypto_skcipher_decrypt(req: subreq);
157}
158
159static int essiv_skcipher_encrypt(struct skcipher_request *req)
160{
161 return essiv_skcipher_crypt(req, enc: true);
162}
163
164static int essiv_skcipher_decrypt(struct skcipher_request *req)
165{
166 return essiv_skcipher_crypt(req, enc: false);
167}
168
169static void essiv_aead_done(void *data, int err)
170{
171 struct aead_request *req = data;
172 struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
173
174 if (err == -EINPROGRESS)
175 goto out;
176
177 kfree(objp: rctx->assoc);
178
179out:
180 aead_request_complete(req, err);
181}
182
183static int essiv_aead_crypt(struct aead_request *req, bool enc)
184{
185 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
186 const struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
187 struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
188 struct aead_request *subreq = &rctx->aead_req;
189 int ivsize = crypto_aead_ivsize(tfm);
190 int ssize = req->assoclen - ivsize;
191 struct scatterlist *src = req->src;
192 int err;
193
194 if (ssize < 0)
195 return -EINVAL;
196
197 crypto_cipher_encrypt_one(tfm: tctx->essiv_cipher, dst: req->iv, src: req->iv);
198
199 /*
200 * dm-crypt embeds the sector number and the IV in the AAD region, so
201 * we have to copy the converted IV into the right scatterlist before
202 * we pass it on.
203 */
204 rctx->assoc = NULL;
205 if (req->src == req->dst || !enc) {
206 scatterwalk_map_and_copy(buf: req->iv, sg: req->dst, start: ssize, nbytes: ivsize, out: 1);
207 } else {
208 u8 *iv = (u8 *)aead_request_ctx(req) + tctx->ivoffset;
209 struct scatterlist *sg;
210 int nents;
211
212 nents = sg_nents_for_len(sg: req->src, len: ssize);
213 if (nents < 0)
214 return -EINVAL;
215
216 memcpy(iv, req->iv, ivsize);
217 sg_init_table(rctx->sg, 4);
218
219 if (unlikely(nents > 1)) {
220 /*
221 * This is a case that rarely occurs in practice, but
222 * for correctness, we have to deal with it nonetheless.
223 */
224 rctx->assoc = kmalloc(ssize, GFP_ATOMIC);
225 if (!rctx->assoc)
226 return -ENOMEM;
227
228 scatterwalk_map_and_copy(buf: rctx->assoc, sg: req->src, start: 0,
229 nbytes: ssize, out: 0);
230 sg_set_buf(sg: rctx->sg, buf: rctx->assoc, buflen: ssize);
231 } else {
232 sg_set_page(sg: rctx->sg, page: sg_page(sg: req->src), len: ssize,
233 offset: req->src->offset);
234 }
235
236 sg_set_buf(sg: rctx->sg + 1, buf: iv, buflen: ivsize);
237 sg = scatterwalk_ffwd(dst: rctx->sg + 2, src: req->src, len: req->assoclen);
238 if (sg != rctx->sg + 2)
239 sg_chain(prv: rctx->sg, prv_nents: 3, sgl: sg);
240
241 src = rctx->sg;
242 }
243
244 aead_request_set_tfm(req: subreq, tfm: tctx->u.aead);
245 aead_request_set_ad(req: subreq, assoclen: req->assoclen);
246 aead_request_set_callback(req: subreq, flags: aead_request_flags(req),
247 compl: essiv_aead_done, data: req);
248 aead_request_set_crypt(req: subreq, src, dst: req->dst, cryptlen: req->cryptlen, iv: req->iv);
249
250 err = enc ? crypto_aead_encrypt(req: subreq) :
251 crypto_aead_decrypt(req: subreq);
252
253 if (rctx->assoc && err != -EINPROGRESS && err != -EBUSY)
254 kfree(objp: rctx->assoc);
255 return err;
256}
257
258static int essiv_aead_encrypt(struct aead_request *req)
259{
260 return essiv_aead_crypt(req, enc: true);
261}
262
263static int essiv_aead_decrypt(struct aead_request *req)
264{
265 return essiv_aead_crypt(req, enc: false);
266}
267
268static int essiv_init_tfm(struct essiv_instance_ctx *ictx,
269 struct essiv_tfm_ctx *tctx)
270{
271 struct crypto_cipher *essiv_cipher;
272 struct crypto_shash *hash;
273 int err;
274
275 essiv_cipher = crypto_alloc_cipher(alg_name: ictx->essiv_cipher_name, type: 0, mask: 0);
276 if (IS_ERR(ptr: essiv_cipher))
277 return PTR_ERR(ptr: essiv_cipher);
278
279 hash = crypto_alloc_shash(alg_name: ictx->shash_driver_name, type: 0, mask: 0);
280 if (IS_ERR(ptr: hash)) {
281 err = PTR_ERR(ptr: hash);
282 goto err_free_essiv_cipher;
283 }
284
285 tctx->essiv_cipher = essiv_cipher;
286 tctx->hash = hash;
287
288 return 0;
289
290err_free_essiv_cipher:
291 crypto_free_cipher(tfm: essiv_cipher);
292 return err;
293}
294
295static int essiv_skcipher_init_tfm(struct crypto_skcipher *tfm)
296{
297 struct skcipher_instance *inst = skcipher_alg_instance(skcipher: tfm);
298 struct essiv_instance_ctx *ictx = skcipher_instance_ctx(inst);
299 struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
300 struct crypto_skcipher *skcipher;
301 int err;
302
303 skcipher = crypto_spawn_skcipher(spawn: &ictx->u.skcipher_spawn);
304 if (IS_ERR(ptr: skcipher))
305 return PTR_ERR(ptr: skcipher);
306
307 crypto_skcipher_set_reqsize(skcipher: tfm, reqsize: sizeof(struct skcipher_request) +
308 crypto_skcipher_reqsize(tfm: skcipher));
309
310 err = essiv_init_tfm(ictx, tctx);
311 if (err) {
312 crypto_free_skcipher(tfm: skcipher);
313 return err;
314 }
315
316 tctx->u.skcipher = skcipher;
317 return 0;
318}
319
320static int essiv_aead_init_tfm(struct crypto_aead *tfm)
321{
322 struct aead_instance *inst = aead_alg_instance(aead: tfm);
323 struct essiv_instance_ctx *ictx = aead_instance_ctx(inst);
324 struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
325 struct crypto_aead *aead;
326 unsigned int subreq_size;
327 int err;
328
329 BUILD_BUG_ON(offsetofend(struct essiv_aead_request_ctx, aead_req) !=
330 sizeof(struct essiv_aead_request_ctx));
331
332 aead = crypto_spawn_aead(spawn: &ictx->u.aead_spawn);
333 if (IS_ERR(ptr: aead))
334 return PTR_ERR(ptr: aead);
335
336 subreq_size = sizeof_field(struct essiv_aead_request_ctx, aead_req) +
337 crypto_aead_reqsize(tfm: aead);
338
339 tctx->ivoffset = offsetof(struct essiv_aead_request_ctx, aead_req) +
340 subreq_size;
341 crypto_aead_set_reqsize(aead: tfm, reqsize: tctx->ivoffset + crypto_aead_ivsize(tfm: aead));
342
343 err = essiv_init_tfm(ictx, tctx);
344 if (err) {
345 crypto_free_aead(tfm: aead);
346 return err;
347 }
348
349 tctx->u.aead = aead;
350 return 0;
351}
352
353static void essiv_skcipher_exit_tfm(struct crypto_skcipher *tfm)
354{
355 struct essiv_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
356
357 crypto_free_skcipher(tfm: tctx->u.skcipher);
358 crypto_free_cipher(tfm: tctx->essiv_cipher);
359 crypto_free_shash(tfm: tctx->hash);
360}
361
362static void essiv_aead_exit_tfm(struct crypto_aead *tfm)
363{
364 struct essiv_tfm_ctx *tctx = crypto_aead_ctx(tfm);
365
366 crypto_free_aead(tfm: tctx->u.aead);
367 crypto_free_cipher(tfm: tctx->essiv_cipher);
368 crypto_free_shash(tfm: tctx->hash);
369}
370
371static void essiv_skcipher_free_instance(struct skcipher_instance *inst)
372{
373 struct essiv_instance_ctx *ictx = skcipher_instance_ctx(inst);
374
375 crypto_drop_skcipher(spawn: &ictx->u.skcipher_spawn);
376 kfree(objp: inst);
377}
378
379static void essiv_aead_free_instance(struct aead_instance *inst)
380{
381 struct essiv_instance_ctx *ictx = aead_instance_ctx(inst);
382
383 crypto_drop_aead(spawn: &ictx->u.aead_spawn);
384 kfree(objp: inst);
385}
386
387static bool parse_cipher_name(char *essiv_cipher_name, const char *cra_name)
388{
389 const char *p, *q;
390 int len;
391
392 /* find the last opening parens */
393 p = strrchr(cra_name, '(');
394 if (!p++)
395 return false;
396
397 /* find the first closing parens in the tail of the string */
398 q = strchr(p, ')');
399 if (!q)
400 return false;
401
402 len = q - p;
403 if (len >= CRYPTO_MAX_ALG_NAME)
404 return false;
405
406 strscpy(essiv_cipher_name, p, len + 1);
407 return true;
408}
409
410static bool essiv_supported_algorithms(const char *essiv_cipher_name,
411 struct shash_alg *hash_alg,
412 int ivsize)
413{
414 struct crypto_alg *alg;
415 bool ret = false;
416
417 alg = crypto_alg_mod_lookup(name: essiv_cipher_name,
418 CRYPTO_ALG_TYPE_CIPHER,
419 CRYPTO_ALG_TYPE_MASK);
420 if (IS_ERR(ptr: alg))
421 return false;
422
423 if (hash_alg->digestsize < alg->cra_cipher.cia_min_keysize ||
424 hash_alg->digestsize > alg->cra_cipher.cia_max_keysize)
425 goto out;
426
427 if (ivsize != alg->cra_blocksize)
428 goto out;
429
430 if (crypto_shash_alg_needs_key(alg: hash_alg))
431 goto out;
432
433 ret = true;
434
435out:
436 crypto_mod_put(alg);
437 return ret;
438}
439
440static int essiv_create(struct crypto_template *tmpl, struct rtattr **tb)
441{
442 struct skcipher_alg_common *skcipher_alg = NULL;
443 struct crypto_attr_type *algt;
444 const char *inner_cipher_name;
445 const char *shash_name;
446 struct skcipher_instance *skcipher_inst = NULL;
447 struct aead_instance *aead_inst = NULL;
448 struct crypto_instance *inst;
449 struct crypto_alg *base, *block_base;
450 struct essiv_instance_ctx *ictx;
451 struct aead_alg *aead_alg = NULL;
452 struct crypto_alg *_hash_alg;
453 struct shash_alg *hash_alg;
454 int ivsize;
455 u32 type;
456 u32 mask;
457 int err;
458
459 algt = crypto_get_attr_type(tb);
460 if (IS_ERR(ptr: algt))
461 return PTR_ERR(ptr: algt);
462
463 inner_cipher_name = crypto_attr_alg_name(rta: tb[1]);
464 if (IS_ERR(ptr: inner_cipher_name))
465 return PTR_ERR(ptr: inner_cipher_name);
466
467 shash_name = crypto_attr_alg_name(rta: tb[2]);
468 if (IS_ERR(ptr: shash_name))
469 return PTR_ERR(ptr: shash_name);
470
471 type = algt->type & algt->mask;
472 mask = crypto_algt_inherited_mask(algt);
473
474 switch (type) {
475 case CRYPTO_ALG_TYPE_LSKCIPHER:
476 skcipher_inst = kzalloc(sizeof(*skcipher_inst) +
477 sizeof(*ictx), GFP_KERNEL);
478 if (!skcipher_inst)
479 return -ENOMEM;
480 inst = skcipher_crypto_instance(inst: skcipher_inst);
481 base = &skcipher_inst->alg.base;
482 ictx = crypto_instance_ctx(inst);
483
484 /* Symmetric cipher, e.g., "cbc(aes)" */
485 err = crypto_grab_skcipher(spawn: &ictx->u.skcipher_spawn, inst,
486 name: inner_cipher_name, type: 0, mask);
487 if (err)
488 goto out_free_inst;
489 skcipher_alg = crypto_spawn_skcipher_alg_common(
490 spawn: &ictx->u.skcipher_spawn);
491 block_base = &skcipher_alg->base;
492 ivsize = skcipher_alg->ivsize;
493 break;
494
495 case CRYPTO_ALG_TYPE_AEAD:
496 aead_inst = kzalloc(sizeof(*aead_inst) +
497 sizeof(*ictx), GFP_KERNEL);
498 if (!aead_inst)
499 return -ENOMEM;
500 inst = aead_crypto_instance(inst: aead_inst);
501 base = &aead_inst->alg.base;
502 ictx = crypto_instance_ctx(inst);
503
504 /* AEAD cipher, e.g., "authenc(hmac(sha256),cbc(aes))" */
505 err = crypto_grab_aead(spawn: &ictx->u.aead_spawn, inst,
506 name: inner_cipher_name, type: 0, mask);
507 if (err)
508 goto out_free_inst;
509 aead_alg = crypto_spawn_aead_alg(spawn: &ictx->u.aead_spawn);
510 block_base = &aead_alg->base;
511 if (!strstarts(str: block_base->cra_name, prefix: "authenc(")) {
512 pr_warn("Only authenc() type AEADs are supported by ESSIV\n");
513 err = -EINVAL;
514 goto out_drop_skcipher;
515 }
516 ivsize = aead_alg->ivsize;
517 break;
518
519 default:
520 return -EINVAL;
521 }
522
523 if (!parse_cipher_name(essiv_cipher_name: ictx->essiv_cipher_name, cra_name: block_base->cra_name)) {
524 pr_warn("Failed to parse ESSIV cipher name from skcipher cra_name\n");
525 err = -EINVAL;
526 goto out_drop_skcipher;
527 }
528
529 /* Synchronous hash, e.g., "sha256" */
530 _hash_alg = crypto_alg_mod_lookup(name: shash_name,
531 CRYPTO_ALG_TYPE_SHASH,
532 CRYPTO_ALG_TYPE_MASK | mask);
533 if (IS_ERR(ptr: _hash_alg)) {
534 err = PTR_ERR(ptr: _hash_alg);
535 goto out_drop_skcipher;
536 }
537 hash_alg = __crypto_shash_alg(alg: _hash_alg);
538
539 /* Check the set of algorithms */
540 if (!essiv_supported_algorithms(essiv_cipher_name: ictx->essiv_cipher_name, hash_alg,
541 ivsize)) {
542 pr_warn("Unsupported essiv instantiation: essiv(%s,%s)\n",
543 block_base->cra_name, hash_alg->base.cra_name);
544 err = -EINVAL;
545 goto out_free_hash;
546 }
547
548 /* record the driver name so we can instantiate this exact algo later */
549 strscpy(ictx->shash_driver_name, hash_alg->base.cra_driver_name);
550
551 /* Instance fields */
552
553 err = -ENAMETOOLONG;
554 if (snprintf(buf: base->cra_name, CRYPTO_MAX_ALG_NAME,
555 fmt: "essiv(%s,%s)", block_base->cra_name,
556 hash_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
557 goto out_free_hash;
558 if (snprintf(buf: base->cra_driver_name, CRYPTO_MAX_ALG_NAME,
559 fmt: "essiv(%s,%s)", block_base->cra_driver_name,
560 hash_alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
561 goto out_free_hash;
562
563 /*
564 * hash_alg wasn't gotten via crypto_grab*(), so we need to inherit its
565 * flags manually.
566 */
567 base->cra_flags |= (hash_alg->base.cra_flags &
568 CRYPTO_ALG_INHERITED_FLAGS);
569 base->cra_blocksize = block_base->cra_blocksize;
570 base->cra_ctxsize = sizeof(struct essiv_tfm_ctx);
571 base->cra_alignmask = block_base->cra_alignmask;
572 base->cra_priority = block_base->cra_priority;
573
574 if (type == CRYPTO_ALG_TYPE_LSKCIPHER) {
575 skcipher_inst->alg.setkey = essiv_skcipher_setkey;
576 skcipher_inst->alg.encrypt = essiv_skcipher_encrypt;
577 skcipher_inst->alg.decrypt = essiv_skcipher_decrypt;
578 skcipher_inst->alg.init = essiv_skcipher_init_tfm;
579 skcipher_inst->alg.exit = essiv_skcipher_exit_tfm;
580
581 skcipher_inst->alg.min_keysize = skcipher_alg->min_keysize;
582 skcipher_inst->alg.max_keysize = skcipher_alg->max_keysize;
583 skcipher_inst->alg.ivsize = ivsize;
584 skcipher_inst->alg.chunksize = skcipher_alg->chunksize;
585
586 skcipher_inst->free = essiv_skcipher_free_instance;
587
588 err = skcipher_register_instance(tmpl, inst: skcipher_inst);
589 } else {
590 aead_inst->alg.setkey = essiv_aead_setkey;
591 aead_inst->alg.setauthsize = essiv_aead_setauthsize;
592 aead_inst->alg.encrypt = essiv_aead_encrypt;
593 aead_inst->alg.decrypt = essiv_aead_decrypt;
594 aead_inst->alg.init = essiv_aead_init_tfm;
595 aead_inst->alg.exit = essiv_aead_exit_tfm;
596
597 aead_inst->alg.ivsize = ivsize;
598 aead_inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg: aead_alg);
599 aead_inst->alg.chunksize = crypto_aead_alg_chunksize(alg: aead_alg);
600
601 aead_inst->free = essiv_aead_free_instance;
602
603 err = aead_register_instance(tmpl, inst: aead_inst);
604 }
605
606 if (err)
607 goto out_free_hash;
608
609 crypto_mod_put(alg: _hash_alg);
610 return 0;
611
612out_free_hash:
613 crypto_mod_put(alg: _hash_alg);
614out_drop_skcipher:
615 if (type == CRYPTO_ALG_TYPE_LSKCIPHER)
616 crypto_drop_skcipher(spawn: &ictx->u.skcipher_spawn);
617 else
618 crypto_drop_aead(spawn: &ictx->u.aead_spawn);
619out_free_inst:
620 kfree(objp: skcipher_inst);
621 kfree(objp: aead_inst);
622 return err;
623}
624
625/* essiv(cipher_name, shash_name) */
626static struct crypto_template essiv_tmpl = {
627 .name = "essiv",
628 .create = essiv_create,
629 .module = THIS_MODULE,
630};
631
632static int __init essiv_module_init(void)
633{
634 return crypto_register_template(tmpl: &essiv_tmpl);
635}
636
637static void __exit essiv_module_exit(void)
638{
639 crypto_unregister_template(tmpl: &essiv_tmpl);
640}
641
642module_init(essiv_module_init);
643module_exit(essiv_module_exit);
644
645MODULE_DESCRIPTION("ESSIV skcipher/aead wrapper for block encryption");
646MODULE_LICENSE("GPL v2");
647MODULE_ALIAS_CRYPTO("essiv");
648MODULE_IMPORT_NS("CRYPTO_INTERNAL");
649

source code of linux/crypto/essiv.c