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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * CCM: Counter with CBC-MAC
4 *
5 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
6 */
7
8#include <crypto/internal/aead.h>
9#include <crypto/internal/cipher.h>
10#include <crypto/internal/hash.h>
11#include <crypto/internal/skcipher.h>
12#include <crypto/scatterwalk.h>
13#include <linux/err.h>
14#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18
19struct ccm_instance_ctx {
20 struct crypto_skcipher_spawn ctr;
21 struct crypto_ahash_spawn mac;
22};
23
24struct crypto_ccm_ctx {
25 struct crypto_ahash *mac;
26 struct crypto_skcipher *ctr;
27};
28
29struct crypto_rfc4309_ctx {
30 struct crypto_aead *child;
31 u8 nonce[3];
32};
33
34struct crypto_rfc4309_req_ctx {
35 struct scatterlist src[3];
36 struct scatterlist dst[3];
37 struct aead_request subreq;
38};
39
40struct crypto_ccm_req_priv_ctx {
41 u8 odata[16];
42 u8 idata[16];
43 u8 auth_tag[16];
44 u32 flags;
45 struct scatterlist src[3];
46 struct scatterlist dst[3];
47 union {
48 struct ahash_request ahreq;
49 struct skcipher_request skreq;
50 };
51};
52
53struct cbcmac_tfm_ctx {
54 struct crypto_cipher *child;
55};
56
57struct cbcmac_desc_ctx {
58 unsigned int len;
59};
60
61static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
62 struct aead_request *req)
63{
64 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
65
66 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
67}
68
69static int set_msg_len(u8 *block, unsigned int msglen, int csize)
70{
71 __be32 data;
72
73 memset(block, 0, csize);
74 block += csize;
75
76 if (csize >= 4)
77 csize = 4;
78 else if (msglen > (1 << (8 * csize)))
79 return -EOVERFLOW;
80
81 data = cpu_to_be32(msglen);
82 memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
83
84 return 0;
85}
86
87static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
88 unsigned int keylen)
89{
90 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
91 struct crypto_skcipher *ctr = ctx->ctr;
92 struct crypto_ahash *mac = ctx->mac;
93 int err;
94
95 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
96 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
97 CRYPTO_TFM_REQ_MASK);
98 err = crypto_skcipher_setkey(ctr, key, keylen);
99 if (err)
100 return err;
101
102 crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
103 crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
104 CRYPTO_TFM_REQ_MASK);
105 return crypto_ahash_setkey(mac, key, keylen);
106}
107
108static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
109 unsigned int authsize)
110{
111 switch (authsize) {
112 case 4:
113 case 6:
114 case 8:
115 case 10:
116 case 12:
117 case 14:
118 case 16:
119 break;
120 default:
121 return -EINVAL;
122 }
123
124 return 0;
125}
126
127static int format_input(u8 *info, struct aead_request *req,
128 unsigned int cryptlen)
129{
130 struct crypto_aead *aead = crypto_aead_reqtfm(req);
131 unsigned int lp = req->iv[0];
132 unsigned int l = lp + 1;
133 unsigned int m;
134
135 m = crypto_aead_authsize(aead);
136
137 memcpy(info, req->iv, 16);
138
139 /* format control info per RFC 3610 and
140 * NIST Special Publication 800-38C
141 */
142 *info |= (8 * ((m - 2) / 2));
143 if (req->assoclen)
144 *info |= 64;
145
146 return set_msg_len(info + 16 - l, cryptlen, l);
147}
148
149static int format_adata(u8 *adata, unsigned int a)
150{
151 int len = 0;
152
153 /* add control info for associated data
154 * RFC 3610 and NIST Special Publication 800-38C
155 */
156 if (a < 65280) {
157 *(__be16 *)adata = cpu_to_be16(a);
158 len = 2;
159 } else {
160 *(__be16 *)adata = cpu_to_be16(0xfffe);
161 *(__be32 *)&adata[2] = cpu_to_be32(a);
162 len = 6;
163 }
164
165 return len;
166}
167
168static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
169 unsigned int cryptlen)
170{
171 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
172 struct crypto_aead *aead = crypto_aead_reqtfm(req);
173 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
174 struct ahash_request *ahreq = &pctx->ahreq;
175 unsigned int assoclen = req->assoclen;
176 struct scatterlist sg[3];
177 u8 *odata = pctx->odata;
178 u8 *idata = pctx->idata;
179 int ilen, err;
180
181 /* format control data for input */
182 err = format_input(odata, req, cryptlen);
183 if (err)
184 goto out;
185
186 sg_init_table(sg, 3);
187 sg_set_buf(&sg[0], odata, 16);
188
189 /* format associated data and compute into mac */
190 if (assoclen) {
191 ilen = format_adata(idata, assoclen);
192 sg_set_buf(&sg[1], idata, ilen);
193 sg_chain(sg, 3, req->src);
194 } else {
195 ilen = 0;
196 sg_chain(sg, 2, req->src);
197 }
198
199 ahash_request_set_tfm(ahreq, ctx->mac);
200 ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
201 ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
202 err = crypto_ahash_init(ahreq);
203 if (err)
204 goto out;
205 err = crypto_ahash_update(ahreq);
206 if (err)
207 goto out;
208
209 /* we need to pad the MAC input to a round multiple of the block size */
210 ilen = 16 - (assoclen + ilen) % 16;
211 if (ilen < 16) {
212 memset(idata, 0, ilen);
213 sg_init_table(sg, 2);
214 sg_set_buf(&sg[0], idata, ilen);
215 if (plain)
216 sg_chain(sg, 2, plain);
217 plain = sg;
218 cryptlen += ilen;
219 }
220
221 ahash_request_set_crypt(ahreq, plain, odata, cryptlen);
222 err = crypto_ahash_finup(ahreq);
223out:
224 return err;
225}
226
227static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
228{
229 struct aead_request *req = areq->data;
230 struct crypto_aead *aead = crypto_aead_reqtfm(req);
231 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
232 u8 *odata = pctx->odata;
233
234 if (!err)
235 scatterwalk_map_and_copy(odata, req->dst,
236 req->assoclen + req->cryptlen,
237 crypto_aead_authsize(aead), 1);
238 aead_request_complete(req, err);
239}
240
241static inline int crypto_ccm_check_iv(const u8 *iv)
242{
243 /* 2 <= L <= 8, so 1 <= L' <= 7. */
244 if (1 > iv[0] || iv[0] > 7)
245 return -EINVAL;
246
247 return 0;
248}
249
250static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
251{
252 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
253 struct scatterlist *sg;
254 u8 *iv = req->iv;
255 int err;
256
257 err = crypto_ccm_check_iv(iv);
258 if (err)
259 return err;
260
261 pctx->flags = aead_request_flags(req);
262
263 /* Note: rfc 3610 and NIST 800-38C require counter of
264 * zero to encrypt auth tag.
265 */
266 memset(iv + 15 - iv[0], 0, iv[0] + 1);
267
268 sg_init_table(pctx->src, 3);
269 sg_set_buf(pctx->src, tag, 16);
270 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
271 if (sg != pctx->src + 1)
272 sg_chain(pctx->src, 2, sg);
273
274 if (req->src != req->dst) {
275 sg_init_table(pctx->dst, 3);
276 sg_set_buf(pctx->dst, tag, 16);
277 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
278 if (sg != pctx->dst + 1)
279 sg_chain(pctx->dst, 2, sg);
280 }
281
282 return 0;
283}
284
285static int crypto_ccm_encrypt(struct aead_request *req)
286{
287 struct crypto_aead *aead = crypto_aead_reqtfm(req);
288 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
289 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
290 struct skcipher_request *skreq = &pctx->skreq;
291 struct scatterlist *dst;
292 unsigned int cryptlen = req->cryptlen;
293 u8 *odata = pctx->odata;
294 u8 *iv = req->iv;
295 int err;
296
297 err = crypto_ccm_init_crypt(req, odata);
298 if (err)
299 return err;
300
301 err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
302 if (err)
303 return err;
304
305 dst = pctx->src;
306 if (req->src != req->dst)
307 dst = pctx->dst;
308
309 skcipher_request_set_tfm(skreq, ctx->ctr);
310 skcipher_request_set_callback(skreq, pctx->flags,
311 crypto_ccm_encrypt_done, req);
312 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
313 err = crypto_skcipher_encrypt(skreq);
314 if (err)
315 return err;
316
317 /* copy authtag to end of dst */
318 scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
319 crypto_aead_authsize(aead), 1);
320 return err;
321}
322
323static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
324 int err)
325{
326 struct aead_request *req = areq->data;
327 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
328 struct crypto_aead *aead = crypto_aead_reqtfm(req);
329 unsigned int authsize = crypto_aead_authsize(aead);
330 unsigned int cryptlen = req->cryptlen - authsize;
331 struct scatterlist *dst;
332
333 pctx->flags = 0;
334
335 dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
336
337 if (!err) {
338 err = crypto_ccm_auth(req, dst, cryptlen);
339 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
340 err = -EBADMSG;
341 }
342 aead_request_complete(req, err);
343}
344
345static int crypto_ccm_decrypt(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 skcipher_request *skreq = &pctx->skreq;
351 struct scatterlist *dst;
352 unsigned int authsize = crypto_aead_authsize(aead);
353 unsigned int cryptlen = req->cryptlen;
354 u8 *authtag = pctx->auth_tag;
355 u8 *odata = pctx->odata;
356 u8 *iv = pctx->idata;
357 int err;
358
359 cryptlen -= authsize;
360
361 err = crypto_ccm_init_crypt(req, authtag);
362 if (err)
363 return err;
364
365 scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
366 authsize, 0);
367
368 dst = pctx->src;
369 if (req->src != req->dst)
370 dst = pctx->dst;
371
372 memcpy(iv, req->iv, 16);
373
374 skcipher_request_set_tfm(skreq, ctx->ctr);
375 skcipher_request_set_callback(skreq, pctx->flags,
376 crypto_ccm_decrypt_done, req);
377 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
378 err = crypto_skcipher_decrypt(skreq);
379 if (err)
380 return err;
381
382 err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
383 if (err)
384 return err;
385
386 /* verify */
387 if (crypto_memneq(authtag, odata, authsize))
388 return -EBADMSG;
389
390 return err;
391}
392
393static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
394{
395 struct aead_instance *inst = aead_alg_instance(tfm);
396 struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
397 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
398 struct crypto_ahash *mac;
399 struct crypto_skcipher *ctr;
400 unsigned long align;
401 int err;
402
403 mac = crypto_spawn_ahash(&ictx->mac);
404 if (IS_ERR(mac))
405 return PTR_ERR(mac);
406
407 ctr = crypto_spawn_skcipher(&ictx->ctr);
408 err = PTR_ERR(ctr);
409 if (IS_ERR(ctr))
410 goto err_free_mac;
411
412 ctx->mac = mac;
413 ctx->ctr = ctr;
414
415 align = crypto_aead_alignmask(tfm);
416 align &= ~(crypto_tfm_ctx_alignment() - 1);
417 crypto_aead_set_reqsize(
418 tfm,
419 align + sizeof(struct crypto_ccm_req_priv_ctx) +
420 max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));
421
422 return 0;
423
424err_free_mac:
425 crypto_free_ahash(mac);
426 return err;
427}
428
429static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
430{
431 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
432
433 crypto_free_ahash(ctx->mac);
434 crypto_free_skcipher(ctx->ctr);
435}
436
437static void crypto_ccm_free(struct aead_instance *inst)
438{
439 struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
440
441 crypto_drop_ahash(&ctx->mac);
442 crypto_drop_skcipher(&ctx->ctr);
443 kfree(inst);
444}
445
446static int crypto_ccm_create_common(struct crypto_template *tmpl,
447 struct rtattr **tb,
448 const char *ctr_name,
449 const char *mac_name)
450{
451 u32 mask;
452 struct aead_instance *inst;
453 struct ccm_instance_ctx *ictx;
454 struct skcipher_alg *ctr;
455 struct hash_alg_common *mac;
456 int err;
457
458 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
459 if (err)
460 return err;
461
462 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
463 if (!inst)
464 return -ENOMEM;
465 ictx = aead_instance_ctx(inst);
466
467 err = crypto_grab_ahash(&ictx->mac, aead_crypto_instance(inst),
468 mac_name, 0, mask | CRYPTO_ALG_ASYNC);
469 if (err)
470 goto err_free_inst;
471 mac = crypto_spawn_ahash_alg(&ictx->mac);
472
473 err = -EINVAL;
474 if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
475 mac->digestsize != 16)
476 goto err_free_inst;
477
478 err = crypto_grab_skcipher(&ictx->ctr, aead_crypto_instance(inst),
479 ctr_name, 0, mask);
480 if (err)
481 goto err_free_inst;
482 ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
483
484 /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
485 err = -EINVAL;
486 if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
487 crypto_skcipher_alg_ivsize(ctr) != 16 ||
488 ctr->base.cra_blocksize != 1)
489 goto err_free_inst;
490
491 /* ctr and cbcmac must use the same underlying block cipher. */
492 if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
493 goto err_free_inst;
494
495 err = -ENAMETOOLONG;
496 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
497 "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
498 goto err_free_inst;
499
500 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
501 "ccm_base(%s,%s)", ctr->base.cra_driver_name,
502 mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
503 goto err_free_inst;
504
505 inst->alg.base.cra_priority = (mac->base.cra_priority +
506 ctr->base.cra_priority) / 2;
507 inst->alg.base.cra_blocksize = 1;
508 inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
509 ctr->base.cra_alignmask;
510 inst->alg.ivsize = 16;
511 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
512 inst->alg.maxauthsize = 16;
513 inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
514 inst->alg.init = crypto_ccm_init_tfm;
515 inst->alg.exit = crypto_ccm_exit_tfm;
516 inst->alg.setkey = crypto_ccm_setkey;
517 inst->alg.setauthsize = crypto_ccm_setauthsize;
518 inst->alg.encrypt = crypto_ccm_encrypt;
519 inst->alg.decrypt = crypto_ccm_decrypt;
520
521 inst->free = crypto_ccm_free;
522
523 err = aead_register_instance(tmpl, inst);
524 if (err) {
525err_free_inst:
526 crypto_ccm_free(inst);
527 }
528 return err;
529}
530
531static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
532{
533 const char *cipher_name;
534 char ctr_name[CRYPTO_MAX_ALG_NAME];
535 char mac_name[CRYPTO_MAX_ALG_NAME];
536
537 cipher_name = crypto_attr_alg_name(tb[1]);
538 if (IS_ERR(cipher_name))
539 return PTR_ERR(cipher_name);
540
541 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
542 cipher_name) >= CRYPTO_MAX_ALG_NAME)
543 return -ENAMETOOLONG;
544
545 if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
546 cipher_name) >= CRYPTO_MAX_ALG_NAME)
547 return -ENAMETOOLONG;
548
549 return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
550}
551
552static int crypto_ccm_base_create(struct crypto_template *tmpl,
553 struct rtattr **tb)
554{
555 const char *ctr_name;
556 const char *mac_name;
557
558 ctr_name = crypto_attr_alg_name(tb[1]);
559 if (IS_ERR(ctr_name))
560 return PTR_ERR(ctr_name);
561
562 mac_name = crypto_attr_alg_name(tb[2]);
563 if (IS_ERR(mac_name))
564 return PTR_ERR(mac_name);
565
566 return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
567}
568
569static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
570 unsigned int keylen)
571{
572 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
573 struct crypto_aead *child = ctx->child;
574
575 if (keylen < 3)
576 return -EINVAL;
577
578 keylen -= 3;
579 memcpy(ctx->nonce, key + keylen, 3);
580
581 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
582 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
583 CRYPTO_TFM_REQ_MASK);
584 return crypto_aead_setkey(child, key, keylen);
585}
586
587static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
588 unsigned int authsize)
589{
590 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
591
592 switch (authsize) {
593 case 8:
594 case 12:
595 case 16:
596 break;
597 default:
598 return -EINVAL;
599 }
600
601 return crypto_aead_setauthsize(ctx->child, authsize);
602}
603
604static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
605{
606 struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
607 struct aead_request *subreq = &rctx->subreq;
608 struct crypto_aead *aead = crypto_aead_reqtfm(req);
609 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
610 struct crypto_aead *child = ctx->child;
611 struct scatterlist *sg;
612 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
613 crypto_aead_alignmask(child) + 1);
614
615 /* L' */
616 iv[0] = 3;
617
618 memcpy(iv + 1, ctx->nonce, 3);
619 memcpy(iv + 4, req->iv, 8);
620
621 scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
622
623 sg_init_table(rctx->src, 3);
624 sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
625 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
626 if (sg != rctx->src + 1)
627 sg_chain(rctx->src, 2, sg);
628
629 if (req->src != req->dst) {
630 sg_init_table(rctx->dst, 3);
631 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
632 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
633 if (sg != rctx->dst + 1)
634 sg_chain(rctx->dst, 2, sg);
635 }
636
637 aead_request_set_tfm(subreq, child);
638 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
639 req->base.data);
640 aead_request_set_crypt(subreq, rctx->src,
641 req->src == req->dst ? rctx->src : rctx->dst,
642 req->cryptlen, iv);
643 aead_request_set_ad(subreq, req->assoclen - 8);
644
645 return subreq;
646}
647
648static int crypto_rfc4309_encrypt(struct aead_request *req)
649{
650 if (req->assoclen != 16 && req->assoclen != 20)
651 return -EINVAL;
652
653 req = crypto_rfc4309_crypt(req);
654
655 return crypto_aead_encrypt(req);
656}
657
658static int crypto_rfc4309_decrypt(struct aead_request *req)
659{
660 if (req->assoclen != 16 && req->assoclen != 20)
661 return -EINVAL;
662
663 req = crypto_rfc4309_crypt(req);
664
665 return crypto_aead_decrypt(req);
666}
667
668static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
669{
670 struct aead_instance *inst = aead_alg_instance(tfm);
671 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
672 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
673 struct crypto_aead *aead;
674 unsigned long align;
675
676 aead = crypto_spawn_aead(spawn);
677 if (IS_ERR(aead))
678 return PTR_ERR(aead);
679
680 ctx->child = aead;
681
682 align = crypto_aead_alignmask(aead);
683 align &= ~(crypto_tfm_ctx_alignment() - 1);
684 crypto_aead_set_reqsize(
685 tfm,
686 sizeof(struct crypto_rfc4309_req_ctx) +
687 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
688 align + 32);
689
690 return 0;
691}
692
693static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
694{
695 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
696
697 crypto_free_aead(ctx->child);
698}
699
700static void crypto_rfc4309_free(struct aead_instance *inst)
701{
702 crypto_drop_aead(aead_instance_ctx(inst));
703 kfree(inst);
704}
705
706static int crypto_rfc4309_create(struct crypto_template *tmpl,
707 struct rtattr **tb)
708{
709 u32 mask;
710 struct aead_instance *inst;
711 struct crypto_aead_spawn *spawn;
712 struct aead_alg *alg;
713 int err;
714
715 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
716 if (err)
717 return err;
718
719 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
720 if (!inst)
721 return -ENOMEM;
722
723 spawn = aead_instance_ctx(inst);
724 err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
725 crypto_attr_alg_name(tb[1]), 0, mask);
726 if (err)
727 goto err_free_inst;
728
729 alg = crypto_spawn_aead_alg(spawn);
730
731 err = -EINVAL;
732
733 /* We only support 16-byte blocks. */
734 if (crypto_aead_alg_ivsize(alg) != 16)
735 goto err_free_inst;
736
737 /* Not a stream cipher? */
738 if (alg->base.cra_blocksize != 1)
739 goto err_free_inst;
740
741 err = -ENAMETOOLONG;
742 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
743 "rfc4309(%s)", alg->base.cra_name) >=
744 CRYPTO_MAX_ALG_NAME ||
745 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
746 "rfc4309(%s)", alg->base.cra_driver_name) >=
747 CRYPTO_MAX_ALG_NAME)
748 goto err_free_inst;
749
750 inst->alg.base.cra_priority = alg->base.cra_priority;
751 inst->alg.base.cra_blocksize = 1;
752 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
753
754 inst->alg.ivsize = 8;
755 inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
756 inst->alg.maxauthsize = 16;
757
758 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
759
760 inst->alg.init = crypto_rfc4309_init_tfm;
761 inst->alg.exit = crypto_rfc4309_exit_tfm;
762
763 inst->alg.setkey = crypto_rfc4309_setkey;
764 inst->alg.setauthsize = crypto_rfc4309_setauthsize;
765 inst->alg.encrypt = crypto_rfc4309_encrypt;
766 inst->alg.decrypt = crypto_rfc4309_decrypt;
767
768 inst->free = crypto_rfc4309_free;
769
770 err = aead_register_instance(tmpl, inst);
771 if (err) {
772err_free_inst:
773 crypto_rfc4309_free(inst);
774 }
775 return err;
776}
777
778static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
779 const u8 *inkey, unsigned int keylen)
780{
781 struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
782
783 return crypto_cipher_setkey(ctx->child, inkey, keylen);
784}
785
786static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
787{
788 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
789 int bs = crypto_shash_digestsize(pdesc->tfm);
790 u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
791
792 ctx->len = 0;
793 memset(dg, 0, bs);
794
795 return 0;
796}
797
798static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
799 unsigned int len)
800{
801 struct crypto_shash *parent = pdesc->tfm;
802 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
803 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
804 struct crypto_cipher *tfm = tctx->child;
805 int bs = crypto_shash_digestsize(parent);
806 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
807
808 while (len > 0) {
809 unsigned int l = min(len, bs - ctx->len);
810
811 crypto_xor(dg + ctx->len, p, l);
812 ctx->len +=l;
813 len -= l;
814 p += l;
815
816 if (ctx->len == bs) {
817 crypto_cipher_encrypt_one(tfm, dg, dg);
818 ctx->len = 0;
819 }
820 }
821
822 return 0;
823}
824
825static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
826{
827 struct crypto_shash *parent = pdesc->tfm;
828 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
829 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
830 struct crypto_cipher *tfm = tctx->child;
831 int bs = crypto_shash_digestsize(parent);
832 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
833
834 if (ctx->len)
835 crypto_cipher_encrypt_one(tfm, dg, dg);
836
837 memcpy(out, dg, bs);
838 return 0;
839}
840
841static int cbcmac_init_tfm(struct crypto_tfm *tfm)
842{
843 struct crypto_cipher *cipher;
844 struct crypto_instance *inst = (void *)tfm->__crt_alg;
845 struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst);
846 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
847
848 cipher = crypto_spawn_cipher(spawn);
849 if (IS_ERR(cipher))
850 return PTR_ERR(cipher);
851
852 ctx->child = cipher;
853
854 return 0;
855};
856
857static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
858{
859 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
860 crypto_free_cipher(ctx->child);
861}
862
863static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
864{
865 struct shash_instance *inst;
866 struct crypto_cipher_spawn *spawn;
867 struct crypto_alg *alg;
868 u32 mask;
869 int err;
870
871 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
872 if (err)
873 return err;
874
875 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
876 if (!inst)
877 return -ENOMEM;
878 spawn = shash_instance_ctx(inst);
879
880 err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
881 crypto_attr_alg_name(tb[1]), 0, mask);
882 if (err)
883 goto err_free_inst;
884 alg = crypto_spawn_cipher_alg(spawn);
885
886 err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
887 if (err)
888 goto err_free_inst;
889
890 inst->alg.base.cra_priority = alg->cra_priority;
891 inst->alg.base.cra_blocksize = 1;
892
893 inst->alg.digestsize = alg->cra_blocksize;
894 inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
895 alg->cra_alignmask + 1) +
896 alg->cra_blocksize;
897
898 inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
899 inst->alg.base.cra_init = cbcmac_init_tfm;
900 inst->alg.base.cra_exit = cbcmac_exit_tfm;
901
902 inst->alg.init = crypto_cbcmac_digest_init;
903 inst->alg.update = crypto_cbcmac_digest_update;
904 inst->alg.final = crypto_cbcmac_digest_final;
905 inst->alg.setkey = crypto_cbcmac_digest_setkey;
906
907 inst->free = shash_free_singlespawn_instance;
908
909 err = shash_register_instance(tmpl, inst);
910 if (err) {
911err_free_inst:
912 shash_free_singlespawn_instance(inst);
913 }
914 return err;
915}
916
917static struct crypto_template crypto_ccm_tmpls[] = {
918 {
919 .name = "cbcmac",
920 .create = cbcmac_create,
921 .module = THIS_MODULE,
922 }, {
923 .name = "ccm_base",
924 .create = crypto_ccm_base_create,
925 .module = THIS_MODULE,
926 }, {
927 .name = "ccm",
928 .create = crypto_ccm_create,
929 .module = THIS_MODULE,
930 }, {
931 .name = "rfc4309",
932 .create = crypto_rfc4309_create,
933 .module = THIS_MODULE,
934 },
935};
936
937static int __init crypto_ccm_module_init(void)
938{
939 return crypto_register_templates(crypto_ccm_tmpls,
940 ARRAY_SIZE(crypto_ccm_tmpls));
941}
942
943static void __exit crypto_ccm_module_exit(void)
944{
945 crypto_unregister_templates(crypto_ccm_tmpls,
946 ARRAY_SIZE(crypto_ccm_tmpls));
947}
948
949subsys_initcall(crypto_ccm_module_init);
950module_exit(crypto_ccm_module_exit);
951
952MODULE_LICENSE("GPL");
953MODULE_DESCRIPTION("Counter with CBC MAC");
954MODULE_ALIAS_CRYPTO("ccm_base");
955MODULE_ALIAS_CRYPTO("rfc4309");
956MODULE_ALIAS_CRYPTO("ccm");
957MODULE_ALIAS_CRYPTO("cbcmac");
958MODULE_IMPORT_NS(CRYPTO_INTERNAL);