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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_rfc4309_req_ctx {
40 struct scatterlist src[3];
41 struct scatterlist dst[3];
42 struct aead_request subreq;
43};
44
45struct crypto_ccm_req_priv_ctx {
46 u8 odata[16];
47 u8 idata[16];
48 u8 auth_tag[16];
49 u32 ilen;
50 u32 flags;
51 struct scatterlist src[3];
52 struct scatterlist dst[3];
53 struct ablkcipher_request abreq;
54};
55
56static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
57 struct aead_request *req)
58{
59 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
60
61 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
62}
63
64static int set_msg_len(u8 *block, unsigned int msglen, int csize)
65{
66 __be32 data;
67
68 memset(block, 0, csize);
69 block += csize;
70
71 if (csize >= 4)
72 csize = 4;
73 else if (msglen > (1 << (8 * csize)))
74 return -EOVERFLOW;
75
76 data = cpu_to_be32(msglen);
77 memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
78
79 return 0;
80}
81
82static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
83 unsigned int keylen)
84{
85 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
86 struct crypto_ablkcipher *ctr = ctx->ctr;
87 struct crypto_cipher *tfm = ctx->cipher;
88 int err = 0;
89
90 crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
91 crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
92 CRYPTO_TFM_REQ_MASK);
93 err = crypto_ablkcipher_setkey(ctr, key, keylen);
94 crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
95 CRYPTO_TFM_RES_MASK);
96 if (err)
97 goto out;
98
99 crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
100 crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) &
101 CRYPTO_TFM_REQ_MASK);
102 err = crypto_cipher_setkey(tfm, key, keylen);
103 crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) &
104 CRYPTO_TFM_RES_MASK);
105
106out:
107 return err;
108}
109
110static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
111 unsigned int authsize)
112{
113 switch (authsize) {
114 case 4:
115 case 6:
116 case 8:
117 case 10:
118 case 12:
119 case 14:
120 case 16:
121 break;
122 default:
123 return -EINVAL;
124 }
125
126 return 0;
127}
128
129static int format_input(u8 *info, struct aead_request *req,
130 unsigned int cryptlen)
131{
132 struct crypto_aead *aead = crypto_aead_reqtfm(req);
133 unsigned int lp = req->iv[0];
134 unsigned int l = lp + 1;
135 unsigned int m;
136
137 m = crypto_aead_authsize(aead);
138
139 memcpy(info, req->iv, 16);
140
141 /* format control info per RFC 3610 and
142 * NIST Special Publication 800-38C
143 */
144 *info |= (8 * ((m - 2) / 2));
145 if (req->assoclen)
146 *info |= 64;
147
148 return set_msg_len(info + 16 - l, cryptlen, l);
149}
150
151static int format_adata(u8 *adata, unsigned int a)
152{
153 int len = 0;
154
155 /* add control info for associated data
156 * RFC 3610 and NIST Special Publication 800-38C
157 */
158 if (a < 65280) {
159 *(__be16 *)adata = cpu_to_be16(a);
160 len = 2;
161 } else {
162 *(__be16 *)adata = cpu_to_be16(0xfffe);
163 *(__be32 *)&adata[2] = cpu_to_be32(a);
164 len = 6;
165 }
166
167 return len;
168}
169
170static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n,
171 struct crypto_ccm_req_priv_ctx *pctx)
172{
173 unsigned int bs = 16;
174 u8 *odata = pctx->odata;
175 u8 *idata = pctx->idata;
176 int datalen, getlen;
177
178 datalen = n;
179
180 /* first time in here, block may be partially filled. */
181 getlen = bs - pctx->ilen;
182 if (datalen >= getlen) {
183 memcpy(idata + pctx->ilen, data, getlen);
184 crypto_xor(odata, idata, bs);
185 crypto_cipher_encrypt_one(tfm, odata, odata);
186 datalen -= getlen;
187 data += getlen;
188 pctx->ilen = 0;
189 }
190
191 /* now encrypt rest of data */
192 while (datalen >= bs) {
193 crypto_xor(odata, data, bs);
194 crypto_cipher_encrypt_one(tfm, odata, odata);
195
196 datalen -= bs;
197 data += bs;
198 }
199
200 /* check and see if there's leftover data that wasn't
201 * enough to fill a block.
202 */
203 if (datalen) {
204 memcpy(idata + pctx->ilen, data, datalen);
205 pctx->ilen += datalen;
206 }
207}
208
209static void get_data_to_compute(struct crypto_cipher *tfm,
210 struct crypto_ccm_req_priv_ctx *pctx,
211 struct scatterlist *sg, unsigned int len)
212{
213 struct scatter_walk walk;
214 u8 *data_src;
215 int n;
216
217 scatterwalk_start(&walk, sg);
218
219 while (len) {
220 n = scatterwalk_clamp(&walk, len);
221 if (!n) {
222 scatterwalk_start(&walk, sg_next(walk.sg));
223 n = scatterwalk_clamp(&walk, len);
224 }
225 data_src = scatterwalk_map(&walk);
226
227 compute_mac(tfm, data_src, n, pctx);
228 len -= n;
229
230 scatterwalk_unmap(data_src);
231 scatterwalk_advance(&walk, n);
232 scatterwalk_done(&walk, 0, len);
233 if (len)
234 crypto_yield(pctx->flags);
235 }
236
237 /* any leftover needs padding and then encrypted */
238 if (pctx->ilen) {
239 int padlen;
240 u8 *odata = pctx->odata;
241 u8 *idata = pctx->idata;
242
243 padlen = 16 - pctx->ilen;
244 memset(idata + pctx->ilen, 0, padlen);
245 crypto_xor(odata, idata, 16);
246 crypto_cipher_encrypt_one(tfm, odata, odata);
247 pctx->ilen = 0;
248 }
249}
250
251static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
252 unsigned int cryptlen)
253{
254 struct crypto_aead *aead = crypto_aead_reqtfm(req);
255 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
256 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
257 struct crypto_cipher *cipher = ctx->cipher;
258 unsigned int assoclen = req->assoclen;
259 u8 *odata = pctx->odata;
260 u8 *idata = pctx->idata;
261 int err;
262
263 /* format control data for input */
264 err = format_input(odata, req, cryptlen);
265 if (err)
266 goto out;
267
268 /* encrypt first block to use as start in computing mac */
269 crypto_cipher_encrypt_one(cipher, odata, odata);
270
271 /* format associated data and compute into mac */
272 if (assoclen) {
273 pctx->ilen = format_adata(idata, assoclen);
274 get_data_to_compute(cipher, pctx, req->src, req->assoclen);
275 } else {
276 pctx->ilen = 0;
277 }
278
279 /* compute plaintext into mac */
280 if (cryptlen)
281 get_data_to_compute(cipher, pctx, plain, cryptlen);
282
283out:
284 return err;
285}
286
287static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
288{
289 struct aead_request *req = areq->data;
290 struct crypto_aead *aead = crypto_aead_reqtfm(req);
291 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
292 u8 *odata = pctx->odata;
293
294 if (!err)
295 scatterwalk_map_and_copy(odata, req->dst,
296 req->assoclen + req->cryptlen,
297 crypto_aead_authsize(aead), 1);
298 aead_request_complete(req, err);
299}
300
301static inline int crypto_ccm_check_iv(const u8 *iv)
302{
303 /* 2 <= L <= 8, so 1 <= L' <= 7. */
304 if (1 > iv[0] || iv[0] > 7)
305 return -EINVAL;
306
307 return 0;
308}
309
310static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
311{
312 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
313 struct scatterlist *sg;
314 u8 *iv = req->iv;
315 int err;
316
317 err = crypto_ccm_check_iv(iv);
318 if (err)
319 return err;
320
321 pctx->flags = aead_request_flags(req);
322
323 /* Note: rfc 3610 and NIST 800-38C require counter of
324 * zero to encrypt auth tag.
325 */
326 memset(iv + 15 - iv[0], 0, iv[0] + 1);
327
328 sg_init_table(pctx->src, 3);
329 sg_set_buf(pctx->src, tag, 16);
330 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
331 if (sg != pctx->src + 1)
332 sg_chain(pctx->src, 2, sg);
333
334 if (req->src != req->dst) {
335 sg_init_table(pctx->dst, 3);
336 sg_set_buf(pctx->dst, tag, 16);
337 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
338 if (sg != pctx->dst + 1)
339 sg_chain(pctx->dst, 2, sg);
340 }
341
342 return 0;
343}
344
345static int crypto_ccm_encrypt(struct aead_request *req)
346{
347 struct crypto_aead *aead = crypto_aead_reqtfm(req);
348 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
349 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
350 struct ablkcipher_request *abreq = &pctx->abreq;
351 struct scatterlist *dst;
352 unsigned int cryptlen = req->cryptlen;
353 u8 *odata = pctx->odata;
354 u8 *iv = req->iv;
355 int err;
356
357 err = crypto_ccm_init_crypt(req, odata);
358 if (err)
359 return err;
360
361 err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
362 if (err)
363 return err;
364
365 dst = pctx->src;
366 if (req->src != req->dst)
367 dst = pctx->dst;
368
369 ablkcipher_request_set_tfm(abreq, ctx->ctr);
370 ablkcipher_request_set_callback(abreq, pctx->flags,
371 crypto_ccm_encrypt_done, req);
372 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
373 err = crypto_ablkcipher_encrypt(abreq);
374 if (err)
375 return err;
376
377 /* copy authtag to end of dst */
378 scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
379 crypto_aead_authsize(aead), 1);
380 return err;
381}
382
383static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
384 int err)
385{
386 struct aead_request *req = areq->data;
387 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
388 struct crypto_aead *aead = crypto_aead_reqtfm(req);
389 unsigned int authsize = crypto_aead_authsize(aead);
390 unsigned int cryptlen = req->cryptlen - authsize;
391 struct scatterlist *dst;
392
393 pctx->flags = 0;
394
395 dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
396
397 if (!err) {
398 err = crypto_ccm_auth(req, dst, cryptlen);
399 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
400 err = -EBADMSG;
401 }
402 aead_request_complete(req, err);
403}
404
405static int crypto_ccm_decrypt(struct aead_request *req)
406{
407 struct crypto_aead *aead = crypto_aead_reqtfm(req);
408 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
409 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
410 struct ablkcipher_request *abreq = &pctx->abreq;
411 struct scatterlist *dst;
412 unsigned int authsize = crypto_aead_authsize(aead);
413 unsigned int cryptlen = req->cryptlen;
414 u8 *authtag = pctx->auth_tag;
415 u8 *odata = pctx->odata;
416 u8 *iv = req->iv;
417 int err;
418
419 cryptlen -= authsize;
420
421 err = crypto_ccm_init_crypt(req, authtag);
422 if (err)
423 return err;
424
425 scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
426 authsize, 0);
427
428 dst = pctx->src;
429 if (req->src != req->dst)
430 dst = pctx->dst;
431
432 ablkcipher_request_set_tfm(abreq, ctx->ctr);
433 ablkcipher_request_set_callback(abreq, pctx->flags,
434 crypto_ccm_decrypt_done, req);
435 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
436 err = crypto_ablkcipher_decrypt(abreq);
437 if (err)
438 return err;
439
440 err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
441 if (err)
442 return err;
443
444 /* verify */
445 if (crypto_memneq(authtag, odata, authsize))
446 return -EBADMSG;
447
448 return err;
449}
450
451static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
452{
453 struct aead_instance *inst = aead_alg_instance(tfm);
454 struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
455 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
456 struct crypto_cipher *cipher;
457 struct crypto_ablkcipher *ctr;
458 unsigned long align;
459 int err;
460
461 cipher = crypto_spawn_cipher(&ictx->cipher);
462 if (IS_ERR(cipher))
463 return PTR_ERR(cipher);
464
465 ctr = crypto_spawn_skcipher(&ictx->ctr);
466 err = PTR_ERR(ctr);
467 if (IS_ERR(ctr))
468 goto err_free_cipher;
469
470 ctx->cipher = cipher;
471 ctx->ctr = ctr;
472
473 align = crypto_aead_alignmask(tfm);
474 align &= ~(crypto_tfm_ctx_alignment() - 1);
475 crypto_aead_set_reqsize(
476 tfm,
477 align + sizeof(struct crypto_ccm_req_priv_ctx) +
478 crypto_ablkcipher_reqsize(ctr));
479
480 return 0;
481
482err_free_cipher:
483 crypto_free_cipher(cipher);
484 return err;
485}
486
487static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
488{
489 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
490
491 crypto_free_cipher(ctx->cipher);
492 crypto_free_ablkcipher(ctx->ctr);
493}
494
495static void crypto_ccm_free(struct aead_instance *inst)
496{
497 struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
498
499 crypto_drop_spawn(&ctx->cipher);
500 crypto_drop_skcipher(&ctx->ctr);
501 kfree(inst);
502}
503
504static int crypto_ccm_create_common(struct crypto_template *tmpl,
505 struct rtattr **tb,
506 const char *full_name,
507 const char *ctr_name,
508 const char *cipher_name)
509{
510 struct crypto_attr_type *algt;
511 struct aead_instance *inst;
512 struct crypto_alg *ctr;
513 struct crypto_alg *cipher;
514 struct ccm_instance_ctx *ictx;
515 int err;
516
517 algt = crypto_get_attr_type(tb);
518 if (IS_ERR(algt))
519 return PTR_ERR(algt);
520
521 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
522 return -EINVAL;
523
524 cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER,
525 CRYPTO_ALG_TYPE_MASK);
526 if (IS_ERR(cipher))
527 return PTR_ERR(cipher);
528
529 err = -EINVAL;
530 if (cipher->cra_blocksize != 16)
531 goto out_put_cipher;
532
533 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
534 err = -ENOMEM;
535 if (!inst)
536 goto out_put_cipher;
537
538 ictx = aead_instance_ctx(inst);
539
540 err = crypto_init_spawn(&ictx->cipher, cipher,
541 aead_crypto_instance(inst),
542 CRYPTO_ALG_TYPE_MASK);
543 if (err)
544 goto err_free_inst;
545
546 crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
547 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
548 crypto_requires_sync(algt->type,
549 algt->mask));
550 if (err)
551 goto err_drop_cipher;
552
553 ctr = crypto_skcipher_spawn_alg(&ictx->ctr);
554
555 /* Not a stream cipher? */
556 err = -EINVAL;
557 if (ctr->cra_blocksize != 1)
558 goto err_drop_ctr;
559
560 /* We want the real thing! */
561 if (ctr->cra_ablkcipher.ivsize != 16)
562 goto err_drop_ctr;
563
564 err = -ENAMETOOLONG;
565 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
566 "ccm_base(%s,%s)", ctr->cra_driver_name,
567 cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
568 goto err_drop_ctr;
569
570 memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
571
572 inst->alg.base.cra_flags = ctr->cra_flags & CRYPTO_ALG_ASYNC;
573 inst->alg.base.cra_priority = (cipher->cra_priority +
574 ctr->cra_priority) / 2;
575 inst->alg.base.cra_blocksize = 1;
576 inst->alg.base.cra_alignmask = cipher->cra_alignmask |
577 ctr->cra_alignmask |
578 (__alignof__(u32) - 1);
579 inst->alg.ivsize = 16;
580 inst->alg.maxauthsize = 16;
581 inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
582 inst->alg.init = crypto_ccm_init_tfm;
583 inst->alg.exit = crypto_ccm_exit_tfm;
584 inst->alg.setkey = crypto_ccm_setkey;
585 inst->alg.setauthsize = crypto_ccm_setauthsize;
586 inst->alg.encrypt = crypto_ccm_encrypt;
587 inst->alg.decrypt = crypto_ccm_decrypt;
588
589 inst->free = crypto_ccm_free;
590
591 err = aead_register_instance(tmpl, inst);
592 if (err)
593 goto err_drop_ctr;
594
595out_put_cipher:
596 crypto_mod_put(cipher);
597 return err;
598
599err_drop_ctr:
600 crypto_drop_skcipher(&ictx->ctr);
601err_drop_cipher:
602 crypto_drop_spawn(&ictx->cipher);
603err_free_inst:
604 kfree(inst);
605 goto out_put_cipher;
606}
607
608static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
609{
610 const char *cipher_name;
611 char ctr_name[CRYPTO_MAX_ALG_NAME];
612 char full_name[CRYPTO_MAX_ALG_NAME];
613
614 cipher_name = crypto_attr_alg_name(tb[1]);
615 if (IS_ERR(cipher_name))
616 return PTR_ERR(cipher_name);
617
618 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
619 cipher_name) >= CRYPTO_MAX_ALG_NAME)
620 return -ENAMETOOLONG;
621
622 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
623 CRYPTO_MAX_ALG_NAME)
624 return -ENAMETOOLONG;
625
626 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
627 cipher_name);
628}
629
630static struct crypto_template crypto_ccm_tmpl = {
631 .name = "ccm",
632 .create = crypto_ccm_create,
633 .module = THIS_MODULE,
634};
635
636static int crypto_ccm_base_create(struct crypto_template *tmpl,
637 struct rtattr **tb)
638{
639 const char *ctr_name;
640 const char *cipher_name;
641 char full_name[CRYPTO_MAX_ALG_NAME];
642
643 ctr_name = crypto_attr_alg_name(tb[1]);
644 if (IS_ERR(ctr_name))
645 return PTR_ERR(ctr_name);
646
647 cipher_name = crypto_attr_alg_name(tb[2]);
648 if (IS_ERR(cipher_name))
649 return PTR_ERR(cipher_name);
650
651 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
652 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
653 return -ENAMETOOLONG;
654
655 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
656 cipher_name);
657}
658
659static struct crypto_template crypto_ccm_base_tmpl = {
660 .name = "ccm_base",
661 .create = crypto_ccm_base_create,
662 .module = THIS_MODULE,
663};
664
665static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
666 unsigned int keylen)
667{
668 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
669 struct crypto_aead *child = ctx->child;
670 int err;
671
672 if (keylen < 3)
673 return -EINVAL;
674
675 keylen -= 3;
676 memcpy(ctx->nonce, key + keylen, 3);
677
678 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
679 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
680 CRYPTO_TFM_REQ_MASK);
681 err = crypto_aead_setkey(child, key, keylen);
682 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
683 CRYPTO_TFM_RES_MASK);
684
685 return err;
686}
687
688static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
689 unsigned int authsize)
690{
691 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
692
693 switch (authsize) {
694 case 8:
695 case 12:
696 case 16:
697 break;
698 default:
699 return -EINVAL;
700 }
701
702 return crypto_aead_setauthsize(ctx->child, authsize);
703}
704
705static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
706{
707 struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
708 struct aead_request *subreq = &rctx->subreq;
709 struct crypto_aead *aead = crypto_aead_reqtfm(req);
710 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
711 struct crypto_aead *child = ctx->child;
712 struct scatterlist *sg;
713 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
714 crypto_aead_alignmask(child) + 1);
715
716 /* L' */
717 iv[0] = 3;
718
719 memcpy(iv + 1, ctx->nonce, 3);
720 memcpy(iv + 4, req->iv, 8);
721
722 scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
723
724 sg_init_table(rctx->src, 3);
725 sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
726 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
727 if (sg != rctx->src + 1)
728 sg_chain(rctx->src, 2, sg);
729
730 if (req->src != req->dst) {
731 sg_init_table(rctx->dst, 3);
732 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
733 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
734 if (sg != rctx->dst + 1)
735 sg_chain(rctx->dst, 2, sg);
736 }
737
738 aead_request_set_tfm(subreq, child);
739 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
740 req->base.data);
741 aead_request_set_crypt(subreq, rctx->src,
742 req->src == req->dst ? rctx->src : rctx->dst,
743 req->cryptlen, iv);
744 aead_request_set_ad(subreq, req->assoclen - 8);
745
746 return subreq;
747}
748
749static int crypto_rfc4309_encrypt(struct aead_request *req)
750{
751 if (req->assoclen != 16 && req->assoclen != 20)
752 return -EINVAL;
753
754 req = crypto_rfc4309_crypt(req);
755
756 return crypto_aead_encrypt(req);
757}
758
759static int crypto_rfc4309_decrypt(struct aead_request *req)
760{
761 if (req->assoclen != 16 && req->assoclen != 20)
762 return -EINVAL;
763
764 req = crypto_rfc4309_crypt(req);
765
766 return crypto_aead_decrypt(req);
767}
768
769static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
770{
771 struct aead_instance *inst = aead_alg_instance(tfm);
772 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
773 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
774 struct crypto_aead *aead;
775 unsigned long align;
776
777 aead = crypto_spawn_aead(spawn);
778 if (IS_ERR(aead))
779 return PTR_ERR(aead);
780
781 ctx->child = aead;
782
783 align = crypto_aead_alignmask(aead);
784 align &= ~(crypto_tfm_ctx_alignment() - 1);
785 crypto_aead_set_reqsize(
786 tfm,
787 sizeof(struct crypto_rfc4309_req_ctx) +
788 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
789 align + 32);
790
791 return 0;
792}
793
794static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
795{
796 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
797
798 crypto_free_aead(ctx->child);
799}
800
801static void crypto_rfc4309_free(struct aead_instance *inst)
802{
803 crypto_drop_aead(aead_instance_ctx(inst));
804 kfree(inst);
805}
806
807static int crypto_rfc4309_create(struct crypto_template *tmpl,
808 struct rtattr **tb)
809{
810 struct crypto_attr_type *algt;
811 struct aead_instance *inst;
812 struct crypto_aead_spawn *spawn;
813 struct aead_alg *alg;
814 const char *ccm_name;
815 int err;
816
817 algt = crypto_get_attr_type(tb);
818 if (IS_ERR(algt))
819 return PTR_ERR(algt);
820
821 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
822 return -EINVAL;
823
824 ccm_name = crypto_attr_alg_name(tb[1]);
825 if (IS_ERR(ccm_name))
826 return PTR_ERR(ccm_name);
827
828 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
829 if (!inst)
830 return -ENOMEM;
831
832 spawn = aead_instance_ctx(inst);
833 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
834 err = crypto_grab_aead(spawn, ccm_name, 0,
835 crypto_requires_sync(algt->type, algt->mask));
836 if (err)
837 goto out_free_inst;
838
839 alg = crypto_spawn_aead_alg(spawn);
840
841 err = -EINVAL;
842
843 /* We only support 16-byte blocks. */
844 if (crypto_aead_alg_ivsize(alg) != 16)
845 goto out_drop_alg;
846
847 /* Not a stream cipher? */
848 if (alg->base.cra_blocksize != 1)
849 goto out_drop_alg;
850
851 err = -ENAMETOOLONG;
852 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
853 "rfc4309(%s)", alg->base.cra_name) >=
854 CRYPTO_MAX_ALG_NAME ||
855 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
856 "rfc4309(%s)", alg->base.cra_driver_name) >=
857 CRYPTO_MAX_ALG_NAME)
858 goto out_drop_alg;
859
860 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
861 inst->alg.base.cra_priority = alg->base.cra_priority;
862 inst->alg.base.cra_blocksize = 1;
863 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
864
865 inst->alg.ivsize = 8;
866 inst->alg.maxauthsize = 16;
867
868 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
869
870 inst->alg.init = crypto_rfc4309_init_tfm;
871 inst->alg.exit = crypto_rfc4309_exit_tfm;
872
873 inst->alg.setkey = crypto_rfc4309_setkey;
874 inst->alg.setauthsize = crypto_rfc4309_setauthsize;
875 inst->alg.encrypt = crypto_rfc4309_encrypt;
876 inst->alg.decrypt = crypto_rfc4309_decrypt;
877
878 inst->free = crypto_rfc4309_free;
879
880 err = aead_register_instance(tmpl, inst);
881 if (err)
882 goto out_drop_alg;
883
884out:
885 return err;
886
887out_drop_alg:
888 crypto_drop_aead(spawn);
889out_free_inst:
890 kfree(inst);
891 goto out;
892}
893
894static struct crypto_template crypto_rfc4309_tmpl = {
895 .name = "rfc4309",
896 .create = crypto_rfc4309_create,
897 .module = THIS_MODULE,
898};
899
900static int __init crypto_ccm_module_init(void)
901{
902 int err;
903
904 err = crypto_register_template(&crypto_ccm_base_tmpl);
905 if (err)
906 goto out;
907
908 err = crypto_register_template(&crypto_ccm_tmpl);
909 if (err)
910 goto out_undo_base;
911
912 err = crypto_register_template(&crypto_rfc4309_tmpl);
913 if (err)
914 goto out_undo_ccm;
915
916out:
917 return err;
918
919out_undo_ccm:
920 crypto_unregister_template(&crypto_ccm_tmpl);
921out_undo_base:
922 crypto_unregister_template(&crypto_ccm_base_tmpl);
923 goto out;
924}
925
926static void __exit crypto_ccm_module_exit(void)
927{
928 crypto_unregister_template(&crypto_rfc4309_tmpl);
929 crypto_unregister_template(&crypto_ccm_tmpl);
930 crypto_unregister_template(&crypto_ccm_base_tmpl);
931}
932
933module_init(crypto_ccm_module_init);
934module_exit(crypto_ccm_module_exit);
935
936MODULE_LICENSE("GPL");
937MODULE_DESCRIPTION("Counter with CBC MAC");
938MODULE_ALIAS_CRYPTO("ccm_base");
939MODULE_ALIAS_CRYPTO("rfc4309");
940MODULE_ALIAS_CRYPTO("ccm");
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/hash.h>
15#include <crypto/internal/skcipher.h>
16#include <crypto/scatterwalk.h>
17#include <linux/err.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/slab.h>
22
23#include "internal.h"
24
25struct ccm_instance_ctx {
26 struct crypto_skcipher_spawn ctr;
27 struct crypto_ahash_spawn mac;
28};
29
30struct crypto_ccm_ctx {
31 struct crypto_ahash *mac;
32 struct crypto_skcipher *ctr;
33};
34
35struct crypto_rfc4309_ctx {
36 struct crypto_aead *child;
37 u8 nonce[3];
38};
39
40struct crypto_rfc4309_req_ctx {
41 struct scatterlist src[3];
42 struct scatterlist dst[3];
43 struct aead_request subreq;
44};
45
46struct crypto_ccm_req_priv_ctx {
47 u8 odata[16];
48 u8 idata[16];
49 u8 auth_tag[16];
50 u32 flags;
51 struct scatterlist src[3];
52 struct scatterlist dst[3];
53 struct skcipher_request skreq;
54};
55
56struct cbcmac_tfm_ctx {
57 struct crypto_cipher *child;
58};
59
60struct cbcmac_desc_ctx {
61 unsigned int len;
62};
63
64static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
65 struct aead_request *req)
66{
67 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
68
69 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
70}
71
72static int set_msg_len(u8 *block, unsigned int msglen, int csize)
73{
74 __be32 data;
75
76 memset(block, 0, csize);
77 block += csize;
78
79 if (csize >= 4)
80 csize = 4;
81 else if (msglen > (1 << (8 * csize)))
82 return -EOVERFLOW;
83
84 data = cpu_to_be32(msglen);
85 memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
86
87 return 0;
88}
89
90static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
91 unsigned int keylen)
92{
93 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
94 struct crypto_skcipher *ctr = ctx->ctr;
95 struct crypto_ahash *mac = ctx->mac;
96 int err = 0;
97
98 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
99 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
100 CRYPTO_TFM_REQ_MASK);
101 err = crypto_skcipher_setkey(ctr, key, keylen);
102 crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) &
103 CRYPTO_TFM_RES_MASK);
104 if (err)
105 goto out;
106
107 crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
108 crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
109 CRYPTO_TFM_REQ_MASK);
110 err = crypto_ahash_setkey(mac, key, keylen);
111 crypto_aead_set_flags(aead, crypto_ahash_get_flags(mac) &
112 CRYPTO_TFM_RES_MASK);
113
114out:
115 return err;
116}
117
118static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
119 unsigned int authsize)
120{
121 switch (authsize) {
122 case 4:
123 case 6:
124 case 8:
125 case 10:
126 case 12:
127 case 14:
128 case 16:
129 break;
130 default:
131 return -EINVAL;
132 }
133
134 return 0;
135}
136
137static int format_input(u8 *info, struct aead_request *req,
138 unsigned int cryptlen)
139{
140 struct crypto_aead *aead = crypto_aead_reqtfm(req);
141 unsigned int lp = req->iv[0];
142 unsigned int l = lp + 1;
143 unsigned int m;
144
145 m = crypto_aead_authsize(aead);
146
147 memcpy(info, req->iv, 16);
148
149 /* format control info per RFC 3610 and
150 * NIST Special Publication 800-38C
151 */
152 *info |= (8 * ((m - 2) / 2));
153 if (req->assoclen)
154 *info |= 64;
155
156 return set_msg_len(info + 16 - l, cryptlen, l);
157}
158
159static int format_adata(u8 *adata, unsigned int a)
160{
161 int len = 0;
162
163 /* add control info for associated data
164 * RFC 3610 and NIST Special Publication 800-38C
165 */
166 if (a < 65280) {
167 *(__be16 *)adata = cpu_to_be16(a);
168 len = 2;
169 } else {
170 *(__be16 *)adata = cpu_to_be16(0xfffe);
171 *(__be32 *)&adata[2] = cpu_to_be32(a);
172 len = 6;
173 }
174
175 return len;
176}
177
178static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
179 unsigned int cryptlen)
180{
181 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
182 struct crypto_aead *aead = crypto_aead_reqtfm(req);
183 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
184 AHASH_REQUEST_ON_STACK(ahreq, ctx->mac);
185 unsigned int assoclen = req->assoclen;
186 struct scatterlist sg[3];
187 u8 *odata = pctx->odata;
188 u8 *idata = pctx->idata;
189 int ilen, err;
190
191 /* format control data for input */
192 err = format_input(odata, req, cryptlen);
193 if (err)
194 goto out;
195
196 sg_init_table(sg, 3);
197 sg_set_buf(&sg[0], odata, 16);
198
199 /* format associated data and compute into mac */
200 if (assoclen) {
201 ilen = format_adata(idata, assoclen);
202 sg_set_buf(&sg[1], idata, ilen);
203 sg_chain(sg, 3, req->src);
204 } else {
205 ilen = 0;
206 sg_chain(sg, 2, req->src);
207 }
208
209 ahash_request_set_tfm(ahreq, ctx->mac);
210 ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
211 ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
212 err = crypto_ahash_init(ahreq);
213 if (err)
214 goto out;
215 err = crypto_ahash_update(ahreq);
216 if (err)
217 goto out;
218
219 /* we need to pad the MAC input to a round multiple of the block size */
220 ilen = 16 - (assoclen + ilen) % 16;
221 if (ilen < 16) {
222 memset(idata, 0, ilen);
223 sg_init_table(sg, 2);
224 sg_set_buf(&sg[0], idata, ilen);
225 if (plain)
226 sg_chain(sg, 2, plain);
227 plain = sg;
228 cryptlen += ilen;
229 }
230
231 ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
232 err = crypto_ahash_finup(ahreq);
233out:
234 return err;
235}
236
237static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
238{
239 struct aead_request *req = areq->data;
240 struct crypto_aead *aead = crypto_aead_reqtfm(req);
241 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
242 u8 *odata = pctx->odata;
243
244 if (!err)
245 scatterwalk_map_and_copy(odata, req->dst,
246 req->assoclen + req->cryptlen,
247 crypto_aead_authsize(aead), 1);
248 aead_request_complete(req, err);
249}
250
251static inline int crypto_ccm_check_iv(const u8 *iv)
252{
253 /* 2 <= L <= 8, so 1 <= L' <= 7. */
254 if (1 > iv[0] || iv[0] > 7)
255 return -EINVAL;
256
257 return 0;
258}
259
260static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
261{
262 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
263 struct scatterlist *sg;
264 u8 *iv = req->iv;
265 int err;
266
267 err = crypto_ccm_check_iv(iv);
268 if (err)
269 return err;
270
271 pctx->flags = aead_request_flags(req);
272
273 /* Note: rfc 3610 and NIST 800-38C require counter of
274 * zero to encrypt auth tag.
275 */
276 memset(iv + 15 - iv[0], 0, iv[0] + 1);
277
278 sg_init_table(pctx->src, 3);
279 sg_set_buf(pctx->src, tag, 16);
280 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
281 if (sg != pctx->src + 1)
282 sg_chain(pctx->src, 2, sg);
283
284 if (req->src != req->dst) {
285 sg_init_table(pctx->dst, 3);
286 sg_set_buf(pctx->dst, tag, 16);
287 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
288 if (sg != pctx->dst + 1)
289 sg_chain(pctx->dst, 2, sg);
290 }
291
292 return 0;
293}
294
295static int crypto_ccm_encrypt(struct aead_request *req)
296{
297 struct crypto_aead *aead = crypto_aead_reqtfm(req);
298 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
299 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
300 struct skcipher_request *skreq = &pctx->skreq;
301 struct scatterlist *dst;
302 unsigned int cryptlen = req->cryptlen;
303 u8 *odata = pctx->odata;
304 u8 *iv = req->iv;
305 int err;
306
307 err = crypto_ccm_init_crypt(req, odata);
308 if (err)
309 return err;
310
311 err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
312 if (err)
313 return err;
314
315 dst = pctx->src;
316 if (req->src != req->dst)
317 dst = pctx->dst;
318
319 skcipher_request_set_tfm(skreq, ctx->ctr);
320 skcipher_request_set_callback(skreq, pctx->flags,
321 crypto_ccm_encrypt_done, req);
322 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
323 err = crypto_skcipher_encrypt(skreq);
324 if (err)
325 return err;
326
327 /* copy authtag to end of dst */
328 scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
329 crypto_aead_authsize(aead), 1);
330 return err;
331}
332
333static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
334 int err)
335{
336 struct aead_request *req = areq->data;
337 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
338 struct crypto_aead *aead = crypto_aead_reqtfm(req);
339 unsigned int authsize = crypto_aead_authsize(aead);
340 unsigned int cryptlen = req->cryptlen - authsize;
341 struct scatterlist *dst;
342
343 pctx->flags = 0;
344
345 dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
346
347 if (!err) {
348 err = crypto_ccm_auth(req, dst, cryptlen);
349 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
350 err = -EBADMSG;
351 }
352 aead_request_complete(req, err);
353}
354
355static int crypto_ccm_decrypt(struct aead_request *req)
356{
357 struct crypto_aead *aead = crypto_aead_reqtfm(req);
358 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
359 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
360 struct skcipher_request *skreq = &pctx->skreq;
361 struct scatterlist *dst;
362 unsigned int authsize = crypto_aead_authsize(aead);
363 unsigned int cryptlen = req->cryptlen;
364 u8 *authtag = pctx->auth_tag;
365 u8 *odata = pctx->odata;
366 u8 *iv = pctx->idata;
367 int err;
368
369 cryptlen -= authsize;
370
371 err = crypto_ccm_init_crypt(req, authtag);
372 if (err)
373 return err;
374
375 scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
376 authsize, 0);
377
378 dst = pctx->src;
379 if (req->src != req->dst)
380 dst = pctx->dst;
381
382 memcpy(iv, req->iv, 16);
383
384 skcipher_request_set_tfm(skreq, ctx->ctr);
385 skcipher_request_set_callback(skreq, pctx->flags,
386 crypto_ccm_decrypt_done, req);
387 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
388 err = crypto_skcipher_decrypt(skreq);
389 if (err)
390 return err;
391
392 err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
393 if (err)
394 return err;
395
396 /* verify */
397 if (crypto_memneq(authtag, odata, authsize))
398 return -EBADMSG;
399
400 return err;
401}
402
403static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
404{
405 struct aead_instance *inst = aead_alg_instance(tfm);
406 struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
407 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
408 struct crypto_ahash *mac;
409 struct crypto_skcipher *ctr;
410 unsigned long align;
411 int err;
412
413 mac = crypto_spawn_ahash(&ictx->mac);
414 if (IS_ERR(mac))
415 return PTR_ERR(mac);
416
417 ctr = crypto_spawn_skcipher(&ictx->ctr);
418 err = PTR_ERR(ctr);
419 if (IS_ERR(ctr))
420 goto err_free_mac;
421
422 ctx->mac = mac;
423 ctx->ctr = ctr;
424
425 align = crypto_aead_alignmask(tfm);
426 align &= ~(crypto_tfm_ctx_alignment() - 1);
427 crypto_aead_set_reqsize(
428 tfm,
429 align + sizeof(struct crypto_ccm_req_priv_ctx) +
430 crypto_skcipher_reqsize(ctr));
431
432 return 0;
433
434err_free_mac:
435 crypto_free_ahash(mac);
436 return err;
437}
438
439static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
440{
441 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
442
443 crypto_free_ahash(ctx->mac);
444 crypto_free_skcipher(ctx->ctr);
445}
446
447static void crypto_ccm_free(struct aead_instance *inst)
448{
449 struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
450
451 crypto_drop_ahash(&ctx->mac);
452 crypto_drop_skcipher(&ctx->ctr);
453 kfree(inst);
454}
455
456static int crypto_ccm_create_common(struct crypto_template *tmpl,
457 struct rtattr **tb,
458 const char *full_name,
459 const char *ctr_name,
460 const char *mac_name)
461{
462 struct crypto_attr_type *algt;
463 struct aead_instance *inst;
464 struct skcipher_alg *ctr;
465 struct crypto_alg *mac_alg;
466 struct hash_alg_common *mac;
467 struct ccm_instance_ctx *ictx;
468 int err;
469
470 algt = crypto_get_attr_type(tb);
471 if (IS_ERR(algt))
472 return PTR_ERR(algt);
473
474 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
475 return -EINVAL;
476
477 mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type,
478 CRYPTO_ALG_TYPE_HASH,
479 CRYPTO_ALG_TYPE_AHASH_MASK |
480 CRYPTO_ALG_ASYNC);
481 if (IS_ERR(mac_alg))
482 return PTR_ERR(mac_alg);
483
484 mac = __crypto_hash_alg_common(mac_alg);
485 err = -EINVAL;
486 if (mac->digestsize != 16)
487 goto out_put_mac;
488
489 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
490 err = -ENOMEM;
491 if (!inst)
492 goto out_put_mac;
493
494 ictx = aead_instance_ctx(inst);
495 err = crypto_init_ahash_spawn(&ictx->mac, mac,
496 aead_crypto_instance(inst));
497 if (err)
498 goto err_free_inst;
499
500 crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
501 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
502 crypto_requires_sync(algt->type,
503 algt->mask));
504 if (err)
505 goto err_drop_mac;
506
507 ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
508
509 /* Not a stream cipher? */
510 err = -EINVAL;
511 if (ctr->base.cra_blocksize != 1)
512 goto err_drop_ctr;
513
514 /* We want the real thing! */
515 if (crypto_skcipher_alg_ivsize(ctr) != 16)
516 goto err_drop_ctr;
517
518 err = -ENAMETOOLONG;
519 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
520 "ccm_base(%s,%s)", ctr->base.cra_driver_name,
521 mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
522 goto err_drop_ctr;
523
524 memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
525
526 inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
527 inst->alg.base.cra_priority = (mac->base.cra_priority +
528 ctr->base.cra_priority) / 2;
529 inst->alg.base.cra_blocksize = 1;
530 inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
531 ctr->base.cra_alignmask;
532 inst->alg.ivsize = 16;
533 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
534 inst->alg.maxauthsize = 16;
535 inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
536 inst->alg.init = crypto_ccm_init_tfm;
537 inst->alg.exit = crypto_ccm_exit_tfm;
538 inst->alg.setkey = crypto_ccm_setkey;
539 inst->alg.setauthsize = crypto_ccm_setauthsize;
540 inst->alg.encrypt = crypto_ccm_encrypt;
541 inst->alg.decrypt = crypto_ccm_decrypt;
542
543 inst->free = crypto_ccm_free;
544
545 err = aead_register_instance(tmpl, inst);
546 if (err)
547 goto err_drop_ctr;
548
549out_put_mac:
550 crypto_mod_put(mac_alg);
551 return err;
552
553err_drop_ctr:
554 crypto_drop_skcipher(&ictx->ctr);
555err_drop_mac:
556 crypto_drop_ahash(&ictx->mac);
557err_free_inst:
558 kfree(inst);
559 goto out_put_mac;
560}
561
562static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
563{
564 const char *cipher_name;
565 char ctr_name[CRYPTO_MAX_ALG_NAME];
566 char mac_name[CRYPTO_MAX_ALG_NAME];
567 char full_name[CRYPTO_MAX_ALG_NAME];
568
569 cipher_name = crypto_attr_alg_name(tb[1]);
570 if (IS_ERR(cipher_name))
571 return PTR_ERR(cipher_name);
572
573 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
574 cipher_name) >= CRYPTO_MAX_ALG_NAME)
575 return -ENAMETOOLONG;
576
577 if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
578 cipher_name) >= CRYPTO_MAX_ALG_NAME)
579 return -ENAMETOOLONG;
580
581 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
582 CRYPTO_MAX_ALG_NAME)
583 return -ENAMETOOLONG;
584
585 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
586 mac_name);
587}
588
589static struct crypto_template crypto_ccm_tmpl = {
590 .name = "ccm",
591 .create = crypto_ccm_create,
592 .module = THIS_MODULE,
593};
594
595static int crypto_ccm_base_create(struct crypto_template *tmpl,
596 struct rtattr **tb)
597{
598 const char *ctr_name;
599 const char *cipher_name;
600 char full_name[CRYPTO_MAX_ALG_NAME];
601
602 ctr_name = crypto_attr_alg_name(tb[1]);
603 if (IS_ERR(ctr_name))
604 return PTR_ERR(ctr_name);
605
606 cipher_name = crypto_attr_alg_name(tb[2]);
607 if (IS_ERR(cipher_name))
608 return PTR_ERR(cipher_name);
609
610 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
611 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
612 return -ENAMETOOLONG;
613
614 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
615 cipher_name);
616}
617
618static struct crypto_template crypto_ccm_base_tmpl = {
619 .name = "ccm_base",
620 .create = crypto_ccm_base_create,
621 .module = THIS_MODULE,
622};
623
624static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
625 unsigned int keylen)
626{
627 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
628 struct crypto_aead *child = ctx->child;
629 int err;
630
631 if (keylen < 3)
632 return -EINVAL;
633
634 keylen -= 3;
635 memcpy(ctx->nonce, key + keylen, 3);
636
637 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
638 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
639 CRYPTO_TFM_REQ_MASK);
640 err = crypto_aead_setkey(child, key, keylen);
641 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
642 CRYPTO_TFM_RES_MASK);
643
644 return err;
645}
646
647static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
648 unsigned int authsize)
649{
650 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
651
652 switch (authsize) {
653 case 8:
654 case 12:
655 case 16:
656 break;
657 default:
658 return -EINVAL;
659 }
660
661 return crypto_aead_setauthsize(ctx->child, authsize);
662}
663
664static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
665{
666 struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
667 struct aead_request *subreq = &rctx->subreq;
668 struct crypto_aead *aead = crypto_aead_reqtfm(req);
669 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
670 struct crypto_aead *child = ctx->child;
671 struct scatterlist *sg;
672 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
673 crypto_aead_alignmask(child) + 1);
674
675 /* L' */
676 iv[0] = 3;
677
678 memcpy(iv + 1, ctx->nonce, 3);
679 memcpy(iv + 4, req->iv, 8);
680
681 scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
682
683 sg_init_table(rctx->src, 3);
684 sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
685 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
686 if (sg != rctx->src + 1)
687 sg_chain(rctx->src, 2, sg);
688
689 if (req->src != req->dst) {
690 sg_init_table(rctx->dst, 3);
691 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
692 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
693 if (sg != rctx->dst + 1)
694 sg_chain(rctx->dst, 2, sg);
695 }
696
697 aead_request_set_tfm(subreq, child);
698 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
699 req->base.data);
700 aead_request_set_crypt(subreq, rctx->src,
701 req->src == req->dst ? rctx->src : rctx->dst,
702 req->cryptlen, iv);
703 aead_request_set_ad(subreq, req->assoclen - 8);
704
705 return subreq;
706}
707
708static int crypto_rfc4309_encrypt(struct aead_request *req)
709{
710 if (req->assoclen != 16 && req->assoclen != 20)
711 return -EINVAL;
712
713 req = crypto_rfc4309_crypt(req);
714
715 return crypto_aead_encrypt(req);
716}
717
718static int crypto_rfc4309_decrypt(struct aead_request *req)
719{
720 if (req->assoclen != 16 && req->assoclen != 20)
721 return -EINVAL;
722
723 req = crypto_rfc4309_crypt(req);
724
725 return crypto_aead_decrypt(req);
726}
727
728static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
729{
730 struct aead_instance *inst = aead_alg_instance(tfm);
731 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
732 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
733 struct crypto_aead *aead;
734 unsigned long align;
735
736 aead = crypto_spawn_aead(spawn);
737 if (IS_ERR(aead))
738 return PTR_ERR(aead);
739
740 ctx->child = aead;
741
742 align = crypto_aead_alignmask(aead);
743 align &= ~(crypto_tfm_ctx_alignment() - 1);
744 crypto_aead_set_reqsize(
745 tfm,
746 sizeof(struct crypto_rfc4309_req_ctx) +
747 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
748 align + 32);
749
750 return 0;
751}
752
753static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
754{
755 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
756
757 crypto_free_aead(ctx->child);
758}
759
760static void crypto_rfc4309_free(struct aead_instance *inst)
761{
762 crypto_drop_aead(aead_instance_ctx(inst));
763 kfree(inst);
764}
765
766static int crypto_rfc4309_create(struct crypto_template *tmpl,
767 struct rtattr **tb)
768{
769 struct crypto_attr_type *algt;
770 struct aead_instance *inst;
771 struct crypto_aead_spawn *spawn;
772 struct aead_alg *alg;
773 const char *ccm_name;
774 int err;
775
776 algt = crypto_get_attr_type(tb);
777 if (IS_ERR(algt))
778 return PTR_ERR(algt);
779
780 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
781 return -EINVAL;
782
783 ccm_name = crypto_attr_alg_name(tb[1]);
784 if (IS_ERR(ccm_name))
785 return PTR_ERR(ccm_name);
786
787 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
788 if (!inst)
789 return -ENOMEM;
790
791 spawn = aead_instance_ctx(inst);
792 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
793 err = crypto_grab_aead(spawn, ccm_name, 0,
794 crypto_requires_sync(algt->type, algt->mask));
795 if (err)
796 goto out_free_inst;
797
798 alg = crypto_spawn_aead_alg(spawn);
799
800 err = -EINVAL;
801
802 /* We only support 16-byte blocks. */
803 if (crypto_aead_alg_ivsize(alg) != 16)
804 goto out_drop_alg;
805
806 /* Not a stream cipher? */
807 if (alg->base.cra_blocksize != 1)
808 goto out_drop_alg;
809
810 err = -ENAMETOOLONG;
811 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
812 "rfc4309(%s)", alg->base.cra_name) >=
813 CRYPTO_MAX_ALG_NAME ||
814 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
815 "rfc4309(%s)", alg->base.cra_driver_name) >=
816 CRYPTO_MAX_ALG_NAME)
817 goto out_drop_alg;
818
819 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
820 inst->alg.base.cra_priority = alg->base.cra_priority;
821 inst->alg.base.cra_blocksize = 1;
822 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
823
824 inst->alg.ivsize = 8;
825 inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
826 inst->alg.maxauthsize = 16;
827
828 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
829
830 inst->alg.init = crypto_rfc4309_init_tfm;
831 inst->alg.exit = crypto_rfc4309_exit_tfm;
832
833 inst->alg.setkey = crypto_rfc4309_setkey;
834 inst->alg.setauthsize = crypto_rfc4309_setauthsize;
835 inst->alg.encrypt = crypto_rfc4309_encrypt;
836 inst->alg.decrypt = crypto_rfc4309_decrypt;
837
838 inst->free = crypto_rfc4309_free;
839
840 err = aead_register_instance(tmpl, inst);
841 if (err)
842 goto out_drop_alg;
843
844out:
845 return err;
846
847out_drop_alg:
848 crypto_drop_aead(spawn);
849out_free_inst:
850 kfree(inst);
851 goto out;
852}
853
854static struct crypto_template crypto_rfc4309_tmpl = {
855 .name = "rfc4309",
856 .create = crypto_rfc4309_create,
857 .module = THIS_MODULE,
858};
859
860static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
861 const u8 *inkey, unsigned int keylen)
862{
863 struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
864
865 return crypto_cipher_setkey(ctx->child, inkey, keylen);
866}
867
868static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
869{
870 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
871 int bs = crypto_shash_digestsize(pdesc->tfm);
872 u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
873
874 ctx->len = 0;
875 memset(dg, 0, bs);
876
877 return 0;
878}
879
880static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
881 unsigned int len)
882{
883 struct crypto_shash *parent = pdesc->tfm;
884 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
885 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
886 struct crypto_cipher *tfm = tctx->child;
887 int bs = crypto_shash_digestsize(parent);
888 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
889
890 while (len > 0) {
891 unsigned int l = min(len, bs - ctx->len);
892
893 crypto_xor(dg + ctx->len, p, l);
894 ctx->len +=l;
895 len -= l;
896 p += l;
897
898 if (ctx->len == bs) {
899 crypto_cipher_encrypt_one(tfm, dg, dg);
900 ctx->len = 0;
901 }
902 }
903
904 return 0;
905}
906
907static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
908{
909 struct crypto_shash *parent = pdesc->tfm;
910 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
911 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
912 struct crypto_cipher *tfm = tctx->child;
913 int bs = crypto_shash_digestsize(parent);
914 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
915
916 if (ctx->len)
917 crypto_cipher_encrypt_one(tfm, dg, dg);
918
919 memcpy(out, dg, bs);
920 return 0;
921}
922
923static int cbcmac_init_tfm(struct crypto_tfm *tfm)
924{
925 struct crypto_cipher *cipher;
926 struct crypto_instance *inst = (void *)tfm->__crt_alg;
927 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
928 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
929
930 cipher = crypto_spawn_cipher(spawn);
931 if (IS_ERR(cipher))
932 return PTR_ERR(cipher);
933
934 ctx->child = cipher;
935
936 return 0;
937};
938
939static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
940{
941 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
942 crypto_free_cipher(ctx->child);
943}
944
945static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
946{
947 struct shash_instance *inst;
948 struct crypto_alg *alg;
949 int err;
950
951 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
952 if (err)
953 return err;
954
955 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
956 CRYPTO_ALG_TYPE_MASK);
957 if (IS_ERR(alg))
958 return PTR_ERR(alg);
959
960 inst = shash_alloc_instance("cbcmac", alg);
961 err = PTR_ERR(inst);
962 if (IS_ERR(inst))
963 goto out_put_alg;
964
965 err = crypto_init_spawn(shash_instance_ctx(inst), alg,
966 shash_crypto_instance(inst),
967 CRYPTO_ALG_TYPE_MASK);
968 if (err)
969 goto out_free_inst;
970
971 inst->alg.base.cra_priority = alg->cra_priority;
972 inst->alg.base.cra_blocksize = 1;
973
974 inst->alg.digestsize = alg->cra_blocksize;
975 inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
976 alg->cra_alignmask + 1) +
977 alg->cra_blocksize;
978
979 inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
980 inst->alg.base.cra_init = cbcmac_init_tfm;
981 inst->alg.base.cra_exit = cbcmac_exit_tfm;
982
983 inst->alg.init = crypto_cbcmac_digest_init;
984 inst->alg.update = crypto_cbcmac_digest_update;
985 inst->alg.final = crypto_cbcmac_digest_final;
986 inst->alg.setkey = crypto_cbcmac_digest_setkey;
987
988 err = shash_register_instance(tmpl, inst);
989
990out_free_inst:
991 if (err)
992 shash_free_instance(shash_crypto_instance(inst));
993
994out_put_alg:
995 crypto_mod_put(alg);
996 return err;
997}
998
999static struct crypto_template crypto_cbcmac_tmpl = {
1000 .name = "cbcmac",
1001 .create = cbcmac_create,
1002 .free = shash_free_instance,
1003 .module = THIS_MODULE,
1004};
1005
1006static int __init crypto_ccm_module_init(void)
1007{
1008 int err;
1009
1010 err = crypto_register_template(&crypto_cbcmac_tmpl);
1011 if (err)
1012 goto out;
1013
1014 err = crypto_register_template(&crypto_ccm_base_tmpl);
1015 if (err)
1016 goto out_undo_cbcmac;
1017
1018 err = crypto_register_template(&crypto_ccm_tmpl);
1019 if (err)
1020 goto out_undo_base;
1021
1022 err = crypto_register_template(&crypto_rfc4309_tmpl);
1023 if (err)
1024 goto out_undo_ccm;
1025
1026out:
1027 return err;
1028
1029out_undo_ccm:
1030 crypto_unregister_template(&crypto_ccm_tmpl);
1031out_undo_base:
1032 crypto_unregister_template(&crypto_ccm_base_tmpl);
1033out_undo_cbcmac:
1034 crypto_register_template(&crypto_cbcmac_tmpl);
1035 goto out;
1036}
1037
1038static void __exit crypto_ccm_module_exit(void)
1039{
1040 crypto_unregister_template(&crypto_rfc4309_tmpl);
1041 crypto_unregister_template(&crypto_ccm_tmpl);
1042 crypto_unregister_template(&crypto_ccm_base_tmpl);
1043 crypto_unregister_template(&crypto_cbcmac_tmpl);
1044}
1045
1046module_init(crypto_ccm_module_init);
1047module_exit(crypto_ccm_module_exit);
1048
1049MODULE_LICENSE("GPL");
1050MODULE_DESCRIPTION("Counter with CBC MAC");
1051MODULE_ALIAS_CRYPTO("ccm_base");
1052MODULE_ALIAS_CRYPTO("rfc4309");
1053MODULE_ALIAS_CRYPTO("ccm");