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[mirror_ubuntu-bionic-kernel.git] / crypto / ccm.c
CommitLineData
4a49b499
JL		 1/*
2 * CCM: Counter with CBC-MAC
3 *
4 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#include <crypto/internal/aead.h>
14#include <crypto/internal/skcipher.h>
15#include <crypto/scatterwalk.h>
16#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/slab.h>
21
22#include "internal.h"
23
24struct ccm_instance_ctx {
25 struct crypto_skcipher_spawn ctr;
26 struct crypto_spawn cipher;
27};
28
29struct crypto_ccm_ctx {
30 struct crypto_cipher *cipher;
31 struct crypto_ablkcipher *ctr;
32};
33
34struct crypto_rfc4309_ctx {
35 struct crypto_aead *child;
36 u8 nonce[3];
37};
38
39struct crypto_ccm_req_priv_ctx {
40 u8 odata[16];
41 u8 idata[16];
42 u8 auth_tag[16];
43 u32 ilen;
44 u32 flags;
45 struct scatterlist src[2];
46 struct scatterlist dst[2];
47 struct ablkcipher_request abreq;
48};
49
50static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
51 struct aead_request *req)
52{
53 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
54
55 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
56}
57
58static int set_msg_len(u8 *block, unsigned int msglen, int csize)
59{
60 __be32 data;
61
62 memset(block, 0, csize);
63 block += csize;
64
65 if (csize >= 4)
66 csize = 4;
67 else if (msglen > (1 << (8 * csize)))
68 return -EOVERFLOW;
69
70 data = cpu_to_be32(msglen);
71 memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
72
73 return 0;
74}
75
76static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
77 unsigned int keylen)
78{
79 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
80 struct crypto_ablkcipher *ctr = ctx->ctr;
81 struct crypto_cipher *tfm = ctx->cipher;
82 int err = 0;
83
84 crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
85 crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
86 CRYPTO_TFM_REQ_MASK);
87 err = crypto_ablkcipher_setkey(ctr, key, keylen);
88 crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
89 CRYPTO_TFM_RES_MASK);
90 if (err)
91 goto out;
92
93 crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
94 crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) &
95 CRYPTO_TFM_REQ_MASK);
96 err = crypto_cipher_setkey(tfm, key, keylen);
97 crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) &
98 CRYPTO_TFM_RES_MASK);
99
100out:
101 return err;
102}
103
104static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
105 unsigned int authsize)
106{
107 switch (authsize) {
108 case 4:
109 case 6:
110 case 8:
111 case 10:
112 case 12:
113 case 14:
114 case 16:
115 break;
116 default:
117 return -EINVAL;
118 }
119
120 return 0;
121}
122
123static int format_input(u8 *info, struct aead_request *req,
124 unsigned int cryptlen)
125{
126 struct crypto_aead *aead = crypto_aead_reqtfm(req);
127 unsigned int lp = req->iv[0];
128 unsigned int l = lp + 1;
129 unsigned int m;
130
131 m = crypto_aead_authsize(aead);
132
133 memcpy(info, req->iv, 16);
134
135 /* format control info per RFC 3610 and
136 * NIST Special Publication 800-38C
137 */
138 *info |= (8 * ((m - 2) / 2));
139 if (req->assoclen)
140 *info |= 64;
141
142 return set_msg_len(info + 16 - l, cryptlen, l);
143}
144
145static int format_adata(u8 *adata, unsigned int a)
146{
147 int len = 0;
148
149 /* add control info for associated data
150 * RFC 3610 and NIST Special Publication 800-38C
151 */
152 if (a < 65280) {
153 *(__be16 *)adata = cpu_to_be16(a);
154 len = 2;
155 } else {
156 *(__be16 *)adata = cpu_to_be16(0xfffe);
157 *(__be32 *)&adata[2] = cpu_to_be32(a);
158 len = 6;
159 }
160
161 return len;
162}
163
164static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n,
165 struct crypto_ccm_req_priv_ctx *pctx)
166{
167 unsigned int bs = 16;
168 u8 *odata = pctx->odata;
169 u8 *idata = pctx->idata;
170 int datalen, getlen;
171
172 datalen = n;
173
174 /* first time in here, block may be partially filled. */
175 getlen = bs - pctx->ilen;
176 if (datalen >= getlen) {
177 memcpy(idata + pctx->ilen, data, getlen);
178 crypto_xor(odata, idata, bs);
179 crypto_cipher_encrypt_one(tfm, odata, odata);
180 datalen -= getlen;
181 data += getlen;
182 pctx->ilen = 0;
183 }
184
185 /* now encrypt rest of data */
186 while (datalen >= bs) {
187 crypto_xor(odata, data, bs);
188 crypto_cipher_encrypt_one(tfm, odata, odata);
189
190 datalen -= bs;
191 data += bs;
192 }
193
194 /* check and see if there's leftover data that wasn't
195 * enough to fill a block.
196 */
197 if (datalen) {
198 memcpy(idata + pctx->ilen, data, datalen);
199 pctx->ilen += datalen;
200 }
201}
202
203static void get_data_to_compute(struct crypto_cipher *tfm,
204 struct crypto_ccm_req_priv_ctx *pctx,
205 struct scatterlist *sg, unsigned int len)
206{
207 struct scatter_walk walk;
208 u8 *data_src;
209 int n;
210
211 scatterwalk_start(&walk, sg);
212
213 while (len) {
214 n = scatterwalk_clamp(&walk, len);
215 if (!n) {
216 scatterwalk_start(&walk, sg_next(walk.sg));
217 n = scatterwalk_clamp(&walk, len);
218 }
f0dfc0b0 219 data_src = scatterwalk_map(&walk);
4a49b499
JL		 220
221 compute_mac(tfm, data_src, n, pctx);
222 len -= n;
223
f0dfc0b0 224 scatterwalk_unmap(data_src);
4a49b499
JL		 225 scatterwalk_advance(&walk, n);
226 scatterwalk_done(&walk, 0, len);
227 if (len)
228 crypto_yield(pctx->flags);
229 }
230
231 /* any leftover needs padding and then encrypted */
232 if (pctx->ilen) {
233 int padlen;
234 u8 *odata = pctx->odata;
235 u8 *idata = pctx->idata;
236
237 padlen = 16 - pctx->ilen;
238 memset(idata + pctx->ilen, 0, padlen);
239 crypto_xor(odata, idata, 16);
240 crypto_cipher_encrypt_one(tfm, odata, odata);
241 pctx->ilen = 0;
242 }
243}
244
245static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
246 unsigned int cryptlen)
247{
248 struct crypto_aead *aead = crypto_aead_reqtfm(req);
249 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
250 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
251 struct crypto_cipher *cipher = ctx->cipher;
252 unsigned int assoclen = req->assoclen;
253 u8 *odata = pctx->odata;
254 u8 *idata = pctx->idata;
255 int err;
256
257 /* format control data for input */
258 err = format_input(odata, req, cryptlen);
259 if (err)
260 goto out;
261
262 /* encrypt first block to use as start in computing mac */
263 crypto_cipher_encrypt_one(cipher, odata, odata);
264
265 /* format associated data and compute into mac */
266 if (assoclen) {
267 pctx->ilen = format_adata(idata, assoclen);
268 get_data_to_compute(cipher, pctx, req->assoc, req->assoclen);
516280e7
JW		 269 } else {
270 pctx->ilen = 0;
4a49b499
JL		 271 }
272
273 /* compute plaintext into mac */
274 get_data_to_compute(cipher, pctx, plain, cryptlen);
275
276out:
277 return err;
278}
279
280static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
281{
282 struct aead_request *req = areq->data;
283 struct crypto_aead *aead = crypto_aead_reqtfm(req);
284 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
285 u8 *odata = pctx->odata;
286
287 if (!err)
288 scatterwalk_map_and_copy(odata, req->dst, req->cryptlen,
289 crypto_aead_authsize(aead), 1);
290 aead_request_complete(req, err);
291}
292
293static inline int crypto_ccm_check_iv(const u8 *iv)
294{
295 /* 2 <= L <= 8, so 1 <= L' <= 7. */
296 if (1 > iv[0] || iv[0] > 7)
297 return -EINVAL;
298
299 return 0;
300}
301
302static int crypto_ccm_encrypt(struct aead_request *req)
303{
304 struct crypto_aead *aead = crypto_aead_reqtfm(req);
305 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
306 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
307 struct ablkcipher_request *abreq = &pctx->abreq;
308 struct scatterlist *dst;
309 unsigned int cryptlen = req->cryptlen;
310 u8 *odata = pctx->odata;
311 u8 *iv = req->iv;
312 int err;
313
314 err = crypto_ccm_check_iv(iv);
315 if (err)
316 return err;
317
318 pctx->flags = aead_request_flags(req);
319
320 err = crypto_ccm_auth(req, req->src, cryptlen);
321 if (err)
322 return err;
323
324 /* Note: rfc 3610 and NIST 800-38C require counter of
325 * zero to encrypt auth tag.
326 */
327 memset(iv + 15 - iv[0], 0, iv[0] + 1);
328
329 sg_init_table(pctx->src, 2);
330 sg_set_buf(pctx->src, odata, 16);
331 scatterwalk_sg_chain(pctx->src, 2, req->src);
332
333 dst = pctx->src;
334 if (req->src != req->dst) {
335 sg_init_table(pctx->dst, 2);
336 sg_set_buf(pctx->dst, odata, 16);
337 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
338 dst = pctx->dst;
339 }
340
341 ablkcipher_request_set_tfm(abreq, ctx->ctr);
342 ablkcipher_request_set_callback(abreq, pctx->flags,
343 crypto_ccm_encrypt_done, req);
344 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
345 err = crypto_ablkcipher_encrypt(abreq);
346 if (err)
347 return err;
348
349 /* copy authtag to end of dst */
350 scatterwalk_map_and_copy(odata, req->dst, cryptlen,
351 crypto_aead_authsize(aead), 1);
352 return err;
353}
354
355static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
356 int err)
357{
358 struct aead_request *req = areq->data;
359 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
360 struct crypto_aead *aead = crypto_aead_reqtfm(req);
361 unsigned int authsize = crypto_aead_authsize(aead);
362 unsigned int cryptlen = req->cryptlen - authsize;
363
364 if (!err) {
365 err = crypto_ccm_auth(req, req->dst, cryptlen);
366 if (!err && memcmp(pctx->auth_tag, pctx->odata, authsize))
367 err = -EBADMSG;
368 }
369 aead_request_complete(req, err);
370}
371
372static int crypto_ccm_decrypt(struct aead_request *req)
373{
374 struct crypto_aead *aead = crypto_aead_reqtfm(req);
375 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
376 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
377 struct ablkcipher_request *abreq = &pctx->abreq;
378 struct scatterlist *dst;
379 unsigned int authsize = crypto_aead_authsize(aead);
380 unsigned int cryptlen = req->cryptlen;
381 u8 *authtag = pctx->auth_tag;
382 u8 *odata = pctx->odata;
383 u8 *iv = req->iv;
384 int err;
385
386 if (cryptlen < authsize)
387 return -EINVAL;
388 cryptlen -= authsize;
389
390 err = crypto_ccm_check_iv(iv);
391 if (err)
392 return err;
393
394 pctx->flags = aead_request_flags(req);
395
396 scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0);
397
398 memset(iv + 15 - iv[0], 0, iv[0] + 1);
399
400 sg_init_table(pctx->src, 2);
401 sg_set_buf(pctx->src, authtag, 16);
402 scatterwalk_sg_chain(pctx->src, 2, req->src);
403
404 dst = pctx->src;
405 if (req->src != req->dst) {
406 sg_init_table(pctx->dst, 2);
407 sg_set_buf(pctx->dst, authtag, 16);
408 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
409 dst = pctx->dst;
410 }
411
412 ablkcipher_request_set_tfm(abreq, ctx->ctr);
413 ablkcipher_request_set_callback(abreq, pctx->flags,
414 crypto_ccm_decrypt_done, req);
415 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
416 err = crypto_ablkcipher_decrypt(abreq);
417 if (err)
418 return err;
419
420 err = crypto_ccm_auth(req, req->dst, cryptlen);
421 if (err)
422 return err;
423
424 /* verify */
425 if (memcmp(authtag, odata, authsize))
426 return -EBADMSG;
427
428 return err;
429}
430
431static int crypto_ccm_init_tfm(struct crypto_tfm *tfm)
432{
433 struct crypto_instance *inst = (void *)tfm->__crt_alg;
434 struct ccm_instance_ctx *ictx = crypto_instance_ctx(inst);
435 struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
436 struct crypto_cipher *cipher;
437 struct crypto_ablkcipher *ctr;
438 unsigned long align;
439 int err;
440
441 cipher = crypto_spawn_cipher(&ictx->cipher);
442 if (IS_ERR(cipher))
443 return PTR_ERR(cipher);
444
445 ctr = crypto_spawn_skcipher(&ictx->ctr);
446 err = PTR_ERR(ctr);
447 if (IS_ERR(ctr))
448 goto err_free_cipher;
449
450 ctx->cipher = cipher;
451 ctx->ctr = ctr;
452
453 align = crypto_tfm_alg_alignmask(tfm);
454 align &= ~(crypto_tfm_ctx_alignment() - 1);
455 tfm->crt_aead.reqsize = align +
456 sizeof(struct crypto_ccm_req_priv_ctx) +
457 crypto_ablkcipher_reqsize(ctr);
458
459 return 0;
460
461err_free_cipher:
462 crypto_free_cipher(cipher);
463 return err;
464}
465
466static void crypto_ccm_exit_tfm(struct crypto_tfm *tfm)
467{
468 struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
469
470 crypto_free_cipher(ctx->cipher);
471 crypto_free_ablkcipher(ctx->ctr);
472}
473
474static struct crypto_instance *crypto_ccm_alloc_common(struct rtattr **tb,
475 const char *full_name,
476 const char *ctr_name,
477 const char *cipher_name)
478{
479 struct crypto_attr_type *algt;
480 struct crypto_instance *inst;
481 struct crypto_alg *ctr;
482 struct crypto_alg *cipher;
483 struct ccm_instance_ctx *ictx;
484 int err;
485
486 algt = crypto_get_attr_type(tb);
4a49b499 487 if (IS_ERR(algt))
3e8afe35 488 return ERR_CAST(algt);
4a49b499
JL		 489
490 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
491 return ERR_PTR(-EINVAL);
492
493 cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER,
494 CRYPTO_ALG_TYPE_MASK);
4a49b499 495 if (IS_ERR(cipher))
3e8afe35 496 return ERR_CAST(cipher);
4a49b499
JL		 497
498 err = -EINVAL;
499 if (cipher->cra_blocksize != 16)
500 goto out_put_cipher;
501
502 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
503 err = -ENOMEM;
504 if (!inst)
505 goto out_put_cipher;
506
507 ictx = crypto_instance_ctx(inst);
508
509 err = crypto_init_spawn(&ictx->cipher, cipher, inst,
510 CRYPTO_ALG_TYPE_MASK);
511 if (err)
512 goto err_free_inst;
513
514 crypto_set_skcipher_spawn(&ictx->ctr, inst);
515 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
516 crypto_requires_sync(algt->type,
517 algt->mask));
518 if (err)
519 goto err_drop_cipher;
520
521 ctr = crypto_skcipher_spawn_alg(&ictx->ctr);
522
523 /* Not a stream cipher? */
524 err = -EINVAL;
525 if (ctr->cra_blocksize != 1)
526 goto err_drop_ctr;
527
528 /* We want the real thing! */
529 if (ctr->cra_ablkcipher.ivsize != 16)
530 goto err_drop_ctr;
531
532 err = -ENAMETOOLONG;
533 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
534 "ccm_base(%s,%s)", ctr->cra_driver_name,
535 cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
536 goto err_drop_ctr;
537
538 memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
539
540 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
541 inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
542 inst->alg.cra_priority = cipher->cra_priority + ctr->cra_priority;
543 inst->alg.cra_blocksize = 1;
544 inst->alg.cra_alignmask = cipher->cra_alignmask | ctr->cra_alignmask |
545 (__alignof__(u32) - 1);
546 inst->alg.cra_type = &crypto_aead_type;
547 inst->alg.cra_aead.ivsize = 16;
548 inst->alg.cra_aead.maxauthsize = 16;
549 inst->alg.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
550 inst->alg.cra_init = crypto_ccm_init_tfm;
551 inst->alg.cra_exit = crypto_ccm_exit_tfm;
552 inst->alg.cra_aead.setkey = crypto_ccm_setkey;
553 inst->alg.cra_aead.setauthsize = crypto_ccm_setauthsize;
554 inst->alg.cra_aead.encrypt = crypto_ccm_encrypt;
555 inst->alg.cra_aead.decrypt = crypto_ccm_decrypt;
556
557out:
558 crypto_mod_put(cipher);
559 return inst;
560
561err_drop_ctr:
562 crypto_drop_skcipher(&ictx->ctr);
563err_drop_cipher:
564 crypto_drop_spawn(&ictx->cipher);
565err_free_inst:
566 kfree(inst);
567out_put_cipher:
568 inst = ERR_PTR(err);
569 goto out;
570}
571
572static struct crypto_instance *crypto_ccm_alloc(struct rtattr **tb)
573{
4a49b499
JL		 574 const char *cipher_name;
575 char ctr_name[CRYPTO_MAX_ALG_NAME];
576 char full_name[CRYPTO_MAX_ALG_NAME];
577
578 cipher_name = crypto_attr_alg_name(tb[1]);
4a49b499 579 if (IS_ERR(cipher_name))
3e8afe35 580 return ERR_CAST(cipher_name);
4a49b499
JL		 581
582 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
583 cipher_name) >= CRYPTO_MAX_ALG_NAME)
584 return ERR_PTR(-ENAMETOOLONG);
585
586 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
587 CRYPTO_MAX_ALG_NAME)
588 return ERR_PTR(-ENAMETOOLONG);
589
590 return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
591}
592
593static void crypto_ccm_free(struct crypto_instance *inst)
594{
595 struct ccm_instance_ctx *ctx = crypto_instance_ctx(inst);
596
597 crypto_drop_spawn(&ctx->cipher);
598 crypto_drop_skcipher(&ctx->ctr);
599 kfree(inst);
600}
601
602static struct crypto_template crypto_ccm_tmpl = {
603 .name = "ccm",
604 .alloc = crypto_ccm_alloc,
605 .free = crypto_ccm_free,
606 .module = THIS_MODULE,
607};
608
609static struct crypto_instance *crypto_ccm_base_alloc(struct rtattr **tb)
610{
4a49b499
JL		 611 const char *ctr_name;
612 const char *cipher_name;
613 char full_name[CRYPTO_MAX_ALG_NAME];
614
615 ctr_name = crypto_attr_alg_name(tb[1]);
4a49b499 616 if (IS_ERR(ctr_name))
3e8afe35 617 return ERR_CAST(ctr_name);
4a49b499
JL		 618
619 cipher_name = crypto_attr_alg_name(tb[2]);
4a49b499 620 if (IS_ERR(cipher_name))
3e8afe35 621 return ERR_CAST(cipher_name);
4a49b499
JL		 622
623 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
624 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
625 return ERR_PTR(-ENAMETOOLONG);
626
627 return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
628}
629
630static struct crypto_template crypto_ccm_base_tmpl = {
631 .name = "ccm_base",
632 .alloc = crypto_ccm_base_alloc,
633 .free = crypto_ccm_free,
634 .module = THIS_MODULE,
635};
636
637static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
638 unsigned int keylen)
639{
640 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
641 struct crypto_aead *child = ctx->child;
642 int err;
643
644 if (keylen < 3)
645 return -EINVAL;
646
647 keylen -= 3;
648 memcpy(ctx->nonce, key + keylen, 3);
649
650 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
651 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
652 CRYPTO_TFM_REQ_MASK);
653 err = crypto_aead_setkey(child, key, keylen);
654 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
655 CRYPTO_TFM_RES_MASK);
656
657 return err;
658}
659
660static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
661 unsigned int authsize)
662{
663 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
664
665 switch (authsize) {
666 case 8:
667 case 12:
668 case 16:
669 break;
670 default:
671 return -EINVAL;
672 }
673
674 return crypto_aead_setauthsize(ctx->child, authsize);
675}
676
677static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
678{
679 struct aead_request *subreq = aead_request_ctx(req);
680 struct crypto_aead *aead = crypto_aead_reqtfm(req);
681 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
682 struct crypto_aead *child = ctx->child;
683 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
684 crypto_aead_alignmask(child) + 1);
685
686 /* L' */
687 iv[0] = 3;
688
689 memcpy(iv + 1, ctx->nonce, 3);
690 memcpy(iv + 4, req->iv, 8);
691
692 aead_request_set_tfm(subreq, child);
693 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
694 req->base.data);
695 aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
696 aead_request_set_assoc(subreq, req->assoc, req->assoclen);
697
698 return subreq;
699}
700
701static int crypto_rfc4309_encrypt(struct aead_request *req)
702{
703 req = crypto_rfc4309_crypt(req);
704
705 return crypto_aead_encrypt(req);
706}
707
708static int crypto_rfc4309_decrypt(struct aead_request *req)
709{
710 req = crypto_rfc4309_crypt(req);
711
712 return crypto_aead_decrypt(req);
713}
714
715static int crypto_rfc4309_init_tfm(struct crypto_tfm *tfm)
716{
717 struct crypto_instance *inst = (void *)tfm->__crt_alg;
718 struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
719 struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
720 struct crypto_aead *aead;
721 unsigned long align;
722
723 aead = crypto_spawn_aead(spawn);
724 if (IS_ERR(aead))
725 return PTR_ERR(aead);
726
727 ctx->child = aead;
728
729 align = crypto_aead_alignmask(aead);
730 align &= ~(crypto_tfm_ctx_alignment() - 1);
731 tfm->crt_aead.reqsize = sizeof(struct aead_request) +
732 ALIGN(crypto_aead_reqsize(aead),
733 crypto_tfm_ctx_alignment()) +
734 align + 16;
735
736 return 0;
737}
738
739static void crypto_rfc4309_exit_tfm(struct crypto_tfm *tfm)
740{
741 struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
742
743 crypto_free_aead(ctx->child);
744}
745
746static struct crypto_instance *crypto_rfc4309_alloc(struct rtattr **tb)
747{
748 struct crypto_attr_type *algt;
749 struct crypto_instance *inst;
750 struct crypto_aead_spawn *spawn;
751 struct crypto_alg *alg;
752 const char *ccm_name;
753 int err;
754
755 algt = crypto_get_attr_type(tb);
4a49b499 756 if (IS_ERR(algt))
3e8afe35 757 return ERR_CAST(algt);
4a49b499
JL		 758
759 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
760 return ERR_PTR(-EINVAL);
761
762 ccm_name = crypto_attr_alg_name(tb[1]);
4a49b499 763 if (IS_ERR(ccm_name))
3e8afe35 764 return ERR_CAST(ccm_name);
4a49b499
JL		 765
766 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
767 if (!inst)
768 return ERR_PTR(-ENOMEM);
769
770 spawn = crypto_instance_ctx(inst);
771 crypto_set_aead_spawn(spawn, inst);
772 err = crypto_grab_aead(spawn, ccm_name, 0,
773 crypto_requires_sync(algt->type, algt->mask));
774 if (err)
775 goto out_free_inst;
776
777 alg = crypto_aead_spawn_alg(spawn);
778
779 err = -EINVAL;
780
781 /* We only support 16-byte blocks. */
782 if (alg->cra_aead.ivsize != 16)
783 goto out_drop_alg;
784
785 /* Not a stream cipher? */
786 if (alg->cra_blocksize != 1)
787 goto out_drop_alg;
788
789 err = -ENAMETOOLONG;
790 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
791 "rfc4309(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
792 snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
793 "rfc4309(%s)", alg->cra_driver_name) >=
794 CRYPTO_MAX_ALG_NAME)
795 goto out_drop_alg;
796
797 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
798 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
799 inst->alg.cra_priority = alg->cra_priority;
800 inst->alg.cra_blocksize = 1;
801 inst->alg.cra_alignmask = alg->cra_alignmask;
802 inst->alg.cra_type = &crypto_nivaead_type;
803
804 inst->alg.cra_aead.ivsize = 8;
805 inst->alg.cra_aead.maxauthsize = 16;
806
807 inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
808
809 inst->alg.cra_init = crypto_rfc4309_init_tfm;
810 inst->alg.cra_exit = crypto_rfc4309_exit_tfm;
811
812 inst->alg.cra_aead.setkey = crypto_rfc4309_setkey;
813 inst->alg.cra_aead.setauthsize = crypto_rfc4309_setauthsize;
814 inst->alg.cra_aead.encrypt = crypto_rfc4309_encrypt;
815 inst->alg.cra_aead.decrypt = crypto_rfc4309_decrypt;
816
817 inst->alg.cra_aead.geniv = "seqiv";
818
819out:
820 return inst;
821
822out_drop_alg:
823 crypto_drop_aead(spawn);
824out_free_inst:
825 kfree(inst);
826 inst = ERR_PTR(err);
827 goto out;
828}
829
830static void crypto_rfc4309_free(struct crypto_instance *inst)
831{
832 crypto_drop_spawn(crypto_instance_ctx(inst));
833 kfree(inst);
834}
835
836static struct crypto_template crypto_rfc4309_tmpl = {
837 .name = "rfc4309",
838 .alloc = crypto_rfc4309_alloc,
839 .free = crypto_rfc4309_free,
840 .module = THIS_MODULE,
841};
842
843static int __init crypto_ccm_module_init(void)
844{
845 int err;
846
847 err = crypto_register_template(&crypto_ccm_base_tmpl);
848 if (err)
849 goto out;
850
851 err = crypto_register_template(&crypto_ccm_tmpl);
852 if (err)
853 goto out_undo_base;
854
855 err = crypto_register_template(&crypto_rfc4309_tmpl);
856 if (err)
857 goto out_undo_ccm;
858
859out:
860 return err;
861
862out_undo_ccm:
863 crypto_unregister_template(&crypto_ccm_tmpl);
864out_undo_base:
865 crypto_unregister_template(&crypto_ccm_base_tmpl);
866 goto out;
867}
868
869static void __exit crypto_ccm_module_exit(void)
870{
871 crypto_unregister_template(&crypto_rfc4309_tmpl);
872 crypto_unregister_template(&crypto_ccm_tmpl);
873 crypto_unregister_template(&crypto_ccm_base_tmpl);
874}
875
876module_init(crypto_ccm_module_init);
877module_exit(crypto_ccm_module_exit);
878
879MODULE_LICENSE("GPL");
880MODULE_DESCRIPTION("Counter with CBC MAC");
881MODULE_ALIAS("ccm_base");
882MODULE_ALIAS("rfc4309");
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