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