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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);
1/*
2 * CCM: Counter with CBC-MAC
3 *
4 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#include <crypto/internal/aead.h>
14#include <crypto/internal/hash.h>
15#include <crypto/internal/skcipher.h>
16#include <crypto/scatterwalk.h>
17#include <linux/err.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/slab.h>
22
23#include "internal.h"
24
25struct ccm_instance_ctx {
26 struct crypto_skcipher_spawn ctr;
27 struct crypto_ahash_spawn mac;
28};
29
30struct crypto_ccm_ctx {
31 struct crypto_ahash *mac;
32 struct crypto_skcipher *ctr;
33};
34
35struct crypto_rfc4309_ctx {
36 struct crypto_aead *child;
37 u8 nonce[3];
38};
39
40struct crypto_rfc4309_req_ctx {
41 struct scatterlist src[3];
42 struct scatterlist dst[3];
43 struct aead_request subreq;
44};
45
46struct crypto_ccm_req_priv_ctx {
47 u8 odata[16];
48 u8 idata[16];
49 u8 auth_tag[16];
50 u32 flags;
51 struct scatterlist src[3];
52 struct scatterlist dst[3];
53 struct skcipher_request skreq;
54};
55
56struct cbcmac_tfm_ctx {
57 struct crypto_cipher *child;
58};
59
60struct cbcmac_desc_ctx {
61 unsigned int len;
62};
63
64static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
65 struct aead_request *req)
66{
67 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
68
69 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
70}
71
72static int set_msg_len(u8 *block, unsigned int msglen, int csize)
73{
74 __be32 data;
75
76 memset(block, 0, csize);
77 block += csize;
78
79 if (csize >= 4)
80 csize = 4;
81 else if (msglen > (1 << (8 * csize)))
82 return -EOVERFLOW;
83
84 data = cpu_to_be32(msglen);
85 memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
86
87 return 0;
88}
89
90static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
91 unsigned int keylen)
92{
93 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
94 struct crypto_skcipher *ctr = ctx->ctr;
95 struct crypto_ahash *mac = ctx->mac;
96 int err = 0;
97
98 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
99 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
100 CRYPTO_TFM_REQ_MASK);
101 err = crypto_skcipher_setkey(ctr, key, keylen);
102 crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) &
103 CRYPTO_TFM_RES_MASK);
104 if (err)
105 goto out;
106
107 crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
108 crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
109 CRYPTO_TFM_REQ_MASK);
110 err = crypto_ahash_setkey(mac, key, keylen);
111 crypto_aead_set_flags(aead, crypto_ahash_get_flags(mac) &
112 CRYPTO_TFM_RES_MASK);
113
114out:
115 return err;
116}
117
118static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
119 unsigned int authsize)
120{
121 switch (authsize) {
122 case 4:
123 case 6:
124 case 8:
125 case 10:
126 case 12:
127 case 14:
128 case 16:
129 break;
130 default:
131 return -EINVAL;
132 }
133
134 return 0;
135}
136
137static int format_input(u8 *info, struct aead_request *req,
138 unsigned int cryptlen)
139{
140 struct crypto_aead *aead = crypto_aead_reqtfm(req);
141 unsigned int lp = req->iv[0];
142 unsigned int l = lp + 1;
143 unsigned int m;
144
145 m = crypto_aead_authsize(aead);
146
147 memcpy(info, req->iv, 16);
148
149 /* format control info per RFC 3610 and
150 * NIST Special Publication 800-38C
151 */
152 *info |= (8 * ((m - 2) / 2));
153 if (req->assoclen)
154 *info |= 64;
155
156 return set_msg_len(info + 16 - l, cryptlen, l);
157}
158
159static int format_adata(u8 *adata, unsigned int a)
160{
161 int len = 0;
162
163 /* add control info for associated data
164 * RFC 3610 and NIST Special Publication 800-38C
165 */
166 if (a < 65280) {
167 *(__be16 *)adata = cpu_to_be16(a);
168 len = 2;
169 } else {
170 *(__be16 *)adata = cpu_to_be16(0xfffe);
171 *(__be32 *)&adata[2] = cpu_to_be32(a);
172 len = 6;
173 }
174
175 return len;
176}
177
178static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
179 unsigned int cryptlen)
180{
181 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
182 struct crypto_aead *aead = crypto_aead_reqtfm(req);
183 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
184 AHASH_REQUEST_ON_STACK(ahreq, ctx->mac);
185 unsigned int assoclen = req->assoclen;
186 struct scatterlist sg[3];
187 u8 *odata = pctx->odata;
188 u8 *idata = pctx->idata;
189 int ilen, err;
190
191 /* format control data for input */
192 err = format_input(odata, req, cryptlen);
193 if (err)
194 goto out;
195
196 sg_init_table(sg, 3);
197 sg_set_buf(&sg[0], odata, 16);
198
199 /* format associated data and compute into mac */
200 if (assoclen) {
201 ilen = format_adata(idata, assoclen);
202 sg_set_buf(&sg[1], idata, ilen);
203 sg_chain(sg, 3, req->src);
204 } else {
205 ilen = 0;
206 sg_chain(sg, 2, req->src);
207 }
208
209 ahash_request_set_tfm(ahreq, ctx->mac);
210 ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
211 ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
212 err = crypto_ahash_init(ahreq);
213 if (err)
214 goto out;
215 err = crypto_ahash_update(ahreq);
216 if (err)
217 goto out;
218
219 /* we need to pad the MAC input to a round multiple of the block size */
220 ilen = 16 - (assoclen + ilen) % 16;
221 if (ilen < 16) {
222 memset(idata, 0, ilen);
223 sg_init_table(sg, 2);
224 sg_set_buf(&sg[0], idata, ilen);
225 if (plain)
226 sg_chain(sg, 2, plain);
227 plain = sg;
228 cryptlen += ilen;
229 }
230
231 ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
232 err = crypto_ahash_finup(ahreq);
233out:
234 return err;
235}
236
237static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
238{
239 struct aead_request *req = areq->data;
240 struct crypto_aead *aead = crypto_aead_reqtfm(req);
241 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
242 u8 *odata = pctx->odata;
243
244 if (!err)
245 scatterwalk_map_and_copy(odata, req->dst,
246 req->assoclen + req->cryptlen,
247 crypto_aead_authsize(aead), 1);
248 aead_request_complete(req, err);
249}
250
251static inline int crypto_ccm_check_iv(const u8 *iv)
252{
253 /* 2 <= L <= 8, so 1 <= L' <= 7. */
254 if (1 > iv[0] || iv[0] > 7)
255 return -EINVAL;
256
257 return 0;
258}
259
260static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
261{
262 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
263 struct scatterlist *sg;
264 u8 *iv = req->iv;
265 int err;
266
267 err = crypto_ccm_check_iv(iv);
268 if (err)
269 return err;
270
271 pctx->flags = aead_request_flags(req);
272
273 /* Note: rfc 3610 and NIST 800-38C require counter of
274 * zero to encrypt auth tag.
275 */
276 memset(iv + 15 - iv[0], 0, iv[0] + 1);
277
278 sg_init_table(pctx->src, 3);
279 sg_set_buf(pctx->src, tag, 16);
280 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
281 if (sg != pctx->src + 1)
282 sg_chain(pctx->src, 2, sg);
283
284 if (req->src != req->dst) {
285 sg_init_table(pctx->dst, 3);
286 sg_set_buf(pctx->dst, tag, 16);
287 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
288 if (sg != pctx->dst + 1)
289 sg_chain(pctx->dst, 2, sg);
290 }
291
292 return 0;
293}
294
295static int crypto_ccm_encrypt(struct aead_request *req)
296{
297 struct crypto_aead *aead = crypto_aead_reqtfm(req);
298 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
299 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
300 struct skcipher_request *skreq = &pctx->skreq;
301 struct scatterlist *dst;
302 unsigned int cryptlen = req->cryptlen;
303 u8 *odata = pctx->odata;
304 u8 *iv = req->iv;
305 int err;
306
307 err = crypto_ccm_init_crypt(req, odata);
308 if (err)
309 return err;
310
311 err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
312 if (err)
313 return err;
314
315 dst = pctx->src;
316 if (req->src != req->dst)
317 dst = pctx->dst;
318
319 skcipher_request_set_tfm(skreq, ctx->ctr);
320 skcipher_request_set_callback(skreq, pctx->flags,
321 crypto_ccm_encrypt_done, req);
322 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
323 err = crypto_skcipher_encrypt(skreq);
324 if (err)
325 return err;
326
327 /* copy authtag to end of dst */
328 scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
329 crypto_aead_authsize(aead), 1);
330 return err;
331}
332
333static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
334 int err)
335{
336 struct aead_request *req = areq->data;
337 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
338 struct crypto_aead *aead = crypto_aead_reqtfm(req);
339 unsigned int authsize = crypto_aead_authsize(aead);
340 unsigned int cryptlen = req->cryptlen - authsize;
341 struct scatterlist *dst;
342
343 pctx->flags = 0;
344
345 dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
346
347 if (!err) {
348 err = crypto_ccm_auth(req, dst, cryptlen);
349 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
350 err = -EBADMSG;
351 }
352 aead_request_complete(req, err);
353}
354
355static int crypto_ccm_decrypt(struct aead_request *req)
356{
357 struct crypto_aead *aead = crypto_aead_reqtfm(req);
358 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
359 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
360 struct skcipher_request *skreq = &pctx->skreq;
361 struct scatterlist *dst;
362 unsigned int authsize = crypto_aead_authsize(aead);
363 unsigned int cryptlen = req->cryptlen;
364 u8 *authtag = pctx->auth_tag;
365 u8 *odata = pctx->odata;
366 u8 *iv = pctx->idata;
367 int err;
368
369 cryptlen -= authsize;
370
371 err = crypto_ccm_init_crypt(req, authtag);
372 if (err)
373 return err;
374
375 scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
376 authsize, 0);
377
378 dst = pctx->src;
379 if (req->src != req->dst)
380 dst = pctx->dst;
381
382 memcpy(iv, req->iv, 16);
383
384 skcipher_request_set_tfm(skreq, ctx->ctr);
385 skcipher_request_set_callback(skreq, pctx->flags,
386 crypto_ccm_decrypt_done, req);
387 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
388 err = crypto_skcipher_decrypt(skreq);
389 if (err)
390 return err;
391
392 err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
393 if (err)
394 return err;
395
396 /* verify */
397 if (crypto_memneq(authtag, odata, authsize))
398 return -EBADMSG;
399
400 return err;
401}
402
403static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
404{
405 struct aead_instance *inst = aead_alg_instance(tfm);
406 struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
407 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
408 struct crypto_ahash *mac;
409 struct crypto_skcipher *ctr;
410 unsigned long align;
411 int err;
412
413 mac = crypto_spawn_ahash(&ictx->mac);
414 if (IS_ERR(mac))
415 return PTR_ERR(mac);
416
417 ctr = crypto_spawn_skcipher(&ictx->ctr);
418 err = PTR_ERR(ctr);
419 if (IS_ERR(ctr))
420 goto err_free_mac;
421
422 ctx->mac = mac;
423 ctx->ctr = ctr;
424
425 align = crypto_aead_alignmask(tfm);
426 align &= ~(crypto_tfm_ctx_alignment() - 1);
427 crypto_aead_set_reqsize(
428 tfm,
429 align + sizeof(struct crypto_ccm_req_priv_ctx) +
430 crypto_skcipher_reqsize(ctr));
431
432 return 0;
433
434err_free_mac:
435 crypto_free_ahash(mac);
436 return err;
437}
438
439static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
440{
441 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
442
443 crypto_free_ahash(ctx->mac);
444 crypto_free_skcipher(ctx->ctr);
445}
446
447static void crypto_ccm_free(struct aead_instance *inst)
448{
449 struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
450
451 crypto_drop_ahash(&ctx->mac);
452 crypto_drop_skcipher(&ctx->ctr);
453 kfree(inst);
454}
455
456static int crypto_ccm_create_common(struct crypto_template *tmpl,
457 struct rtattr **tb,
458 const char *full_name,
459 const char *ctr_name,
460 const char *mac_name)
461{
462 struct crypto_attr_type *algt;
463 struct aead_instance *inst;
464 struct skcipher_alg *ctr;
465 struct crypto_alg *mac_alg;
466 struct hash_alg_common *mac;
467 struct ccm_instance_ctx *ictx;
468 int err;
469
470 algt = crypto_get_attr_type(tb);
471 if (IS_ERR(algt))
472 return PTR_ERR(algt);
473
474 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
475 return -EINVAL;
476
477 mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type,
478 CRYPTO_ALG_TYPE_HASH,
479 CRYPTO_ALG_TYPE_AHASH_MASK |
480 CRYPTO_ALG_ASYNC);
481 if (IS_ERR(mac_alg))
482 return PTR_ERR(mac_alg);
483
484 mac = __crypto_hash_alg_common(mac_alg);
485 err = -EINVAL;
486 if (mac->digestsize != 16)
487 goto out_put_mac;
488
489 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
490 err = -ENOMEM;
491 if (!inst)
492 goto out_put_mac;
493
494 ictx = aead_instance_ctx(inst);
495 err = crypto_init_ahash_spawn(&ictx->mac, mac,
496 aead_crypto_instance(inst));
497 if (err)
498 goto err_free_inst;
499
500 crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
501 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
502 crypto_requires_sync(algt->type,
503 algt->mask));
504 if (err)
505 goto err_drop_mac;
506
507 ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
508
509 /* Not a stream cipher? */
510 err = -EINVAL;
511 if (ctr->base.cra_blocksize != 1)
512 goto err_drop_ctr;
513
514 /* We want the real thing! */
515 if (crypto_skcipher_alg_ivsize(ctr) != 16)
516 goto err_drop_ctr;
517
518 err = -ENAMETOOLONG;
519 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
520 "ccm_base(%s,%s)", ctr->base.cra_driver_name,
521 mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
522 goto err_drop_ctr;
523
524 memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
525
526 inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
527 inst->alg.base.cra_priority = (mac->base.cra_priority +
528 ctr->base.cra_priority) / 2;
529 inst->alg.base.cra_blocksize = 1;
530 inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
531 ctr->base.cra_alignmask;
532 inst->alg.ivsize = 16;
533 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
534 inst->alg.maxauthsize = 16;
535 inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
536 inst->alg.init = crypto_ccm_init_tfm;
537 inst->alg.exit = crypto_ccm_exit_tfm;
538 inst->alg.setkey = crypto_ccm_setkey;
539 inst->alg.setauthsize = crypto_ccm_setauthsize;
540 inst->alg.encrypt = crypto_ccm_encrypt;
541 inst->alg.decrypt = crypto_ccm_decrypt;
542
543 inst->free = crypto_ccm_free;
544
545 err = aead_register_instance(tmpl, inst);
546 if (err)
547 goto err_drop_ctr;
548
549out_put_mac:
550 crypto_mod_put(mac_alg);
551 return err;
552
553err_drop_ctr:
554 crypto_drop_skcipher(&ictx->ctr);
555err_drop_mac:
556 crypto_drop_ahash(&ictx->mac);
557err_free_inst:
558 kfree(inst);
559 goto out_put_mac;
560}
561
562static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
563{
564 const char *cipher_name;
565 char ctr_name[CRYPTO_MAX_ALG_NAME];
566 char mac_name[CRYPTO_MAX_ALG_NAME];
567 char full_name[CRYPTO_MAX_ALG_NAME];
568
569 cipher_name = crypto_attr_alg_name(tb[1]);
570 if (IS_ERR(cipher_name))
571 return PTR_ERR(cipher_name);
572
573 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
574 cipher_name) >= CRYPTO_MAX_ALG_NAME)
575 return -ENAMETOOLONG;
576
577 if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
578 cipher_name) >= CRYPTO_MAX_ALG_NAME)
579 return -ENAMETOOLONG;
580
581 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
582 CRYPTO_MAX_ALG_NAME)
583 return -ENAMETOOLONG;
584
585 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
586 mac_name);
587}
588
589static struct crypto_template crypto_ccm_tmpl = {
590 .name = "ccm",
591 .create = crypto_ccm_create,
592 .module = THIS_MODULE,
593};
594
595static int crypto_ccm_base_create(struct crypto_template *tmpl,
596 struct rtattr **tb)
597{
598 const char *ctr_name;
599 const char *cipher_name;
600 char full_name[CRYPTO_MAX_ALG_NAME];
601
602 ctr_name = crypto_attr_alg_name(tb[1]);
603 if (IS_ERR(ctr_name))
604 return PTR_ERR(ctr_name);
605
606 cipher_name = crypto_attr_alg_name(tb[2]);
607 if (IS_ERR(cipher_name))
608 return PTR_ERR(cipher_name);
609
610 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
611 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
612 return -ENAMETOOLONG;
613
614 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
615 cipher_name);
616}
617
618static struct crypto_template crypto_ccm_base_tmpl = {
619 .name = "ccm_base",
620 .create = crypto_ccm_base_create,
621 .module = THIS_MODULE,
622};
623
624static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
625 unsigned int keylen)
626{
627 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
628 struct crypto_aead *child = ctx->child;
629 int err;
630
631 if (keylen < 3)
632 return -EINVAL;
633
634 keylen -= 3;
635 memcpy(ctx->nonce, key + keylen, 3);
636
637 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
638 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
639 CRYPTO_TFM_REQ_MASK);
640 err = crypto_aead_setkey(child, key, keylen);
641 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
642 CRYPTO_TFM_RES_MASK);
643
644 return err;
645}
646
647static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
648 unsigned int authsize)
649{
650 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
651
652 switch (authsize) {
653 case 8:
654 case 12:
655 case 16:
656 break;
657 default:
658 return -EINVAL;
659 }
660
661 return crypto_aead_setauthsize(ctx->child, authsize);
662}
663
664static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
665{
666 struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
667 struct aead_request *subreq = &rctx->subreq;
668 struct crypto_aead *aead = crypto_aead_reqtfm(req);
669 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
670 struct crypto_aead *child = ctx->child;
671 struct scatterlist *sg;
672 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
673 crypto_aead_alignmask(child) + 1);
674
675 /* L' */
676 iv[0] = 3;
677
678 memcpy(iv + 1, ctx->nonce, 3);
679 memcpy(iv + 4, req->iv, 8);
680
681 scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
682
683 sg_init_table(rctx->src, 3);
684 sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
685 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
686 if (sg != rctx->src + 1)
687 sg_chain(rctx->src, 2, sg);
688
689 if (req->src != req->dst) {
690 sg_init_table(rctx->dst, 3);
691 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
692 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
693 if (sg != rctx->dst + 1)
694 sg_chain(rctx->dst, 2, sg);
695 }
696
697 aead_request_set_tfm(subreq, child);
698 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
699 req->base.data);
700 aead_request_set_crypt(subreq, rctx->src,
701 req->src == req->dst ? rctx->src : rctx->dst,
702 req->cryptlen, iv);
703 aead_request_set_ad(subreq, req->assoclen - 8);
704
705 return subreq;
706}
707
708static int crypto_rfc4309_encrypt(struct aead_request *req)
709{
710 if (req->assoclen != 16 && req->assoclen != 20)
711 return -EINVAL;
712
713 req = crypto_rfc4309_crypt(req);
714
715 return crypto_aead_encrypt(req);
716}
717
718static int crypto_rfc4309_decrypt(struct aead_request *req)
719{
720 if (req->assoclen != 16 && req->assoclen != 20)
721 return -EINVAL;
722
723 req = crypto_rfc4309_crypt(req);
724
725 return crypto_aead_decrypt(req);
726}
727
728static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
729{
730 struct aead_instance *inst = aead_alg_instance(tfm);
731 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
732 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
733 struct crypto_aead *aead;
734 unsigned long align;
735
736 aead = crypto_spawn_aead(spawn);
737 if (IS_ERR(aead))
738 return PTR_ERR(aead);
739
740 ctx->child = aead;
741
742 align = crypto_aead_alignmask(aead);
743 align &= ~(crypto_tfm_ctx_alignment() - 1);
744 crypto_aead_set_reqsize(
745 tfm,
746 sizeof(struct crypto_rfc4309_req_ctx) +
747 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
748 align + 32);
749
750 return 0;
751}
752
753static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
754{
755 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
756
757 crypto_free_aead(ctx->child);
758}
759
760static void crypto_rfc4309_free(struct aead_instance *inst)
761{
762 crypto_drop_aead(aead_instance_ctx(inst));
763 kfree(inst);
764}
765
766static int crypto_rfc4309_create(struct crypto_template *tmpl,
767 struct rtattr **tb)
768{
769 struct crypto_attr_type *algt;
770 struct aead_instance *inst;
771 struct crypto_aead_spawn *spawn;
772 struct aead_alg *alg;
773 const char *ccm_name;
774 int err;
775
776 algt = crypto_get_attr_type(tb);
777 if (IS_ERR(algt))
778 return PTR_ERR(algt);
779
780 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
781 return -EINVAL;
782
783 ccm_name = crypto_attr_alg_name(tb[1]);
784 if (IS_ERR(ccm_name))
785 return PTR_ERR(ccm_name);
786
787 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
788 if (!inst)
789 return -ENOMEM;
790
791 spawn = aead_instance_ctx(inst);
792 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
793 err = crypto_grab_aead(spawn, ccm_name, 0,
794 crypto_requires_sync(algt->type, algt->mask));
795 if (err)
796 goto out_free_inst;
797
798 alg = crypto_spawn_aead_alg(spawn);
799
800 err = -EINVAL;
801
802 /* We only support 16-byte blocks. */
803 if (crypto_aead_alg_ivsize(alg) != 16)
804 goto out_drop_alg;
805
806 /* Not a stream cipher? */
807 if (alg->base.cra_blocksize != 1)
808 goto out_drop_alg;
809
810 err = -ENAMETOOLONG;
811 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
812 "rfc4309(%s)", alg->base.cra_name) >=
813 CRYPTO_MAX_ALG_NAME ||
814 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
815 "rfc4309(%s)", alg->base.cra_driver_name) >=
816 CRYPTO_MAX_ALG_NAME)
817 goto out_drop_alg;
818
819 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
820 inst->alg.base.cra_priority = alg->base.cra_priority;
821 inst->alg.base.cra_blocksize = 1;
822 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
823
824 inst->alg.ivsize = 8;
825 inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
826 inst->alg.maxauthsize = 16;
827
828 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
829
830 inst->alg.init = crypto_rfc4309_init_tfm;
831 inst->alg.exit = crypto_rfc4309_exit_tfm;
832
833 inst->alg.setkey = crypto_rfc4309_setkey;
834 inst->alg.setauthsize = crypto_rfc4309_setauthsize;
835 inst->alg.encrypt = crypto_rfc4309_encrypt;
836 inst->alg.decrypt = crypto_rfc4309_decrypt;
837
838 inst->free = crypto_rfc4309_free;
839
840 err = aead_register_instance(tmpl, inst);
841 if (err)
842 goto out_drop_alg;
843
844out:
845 return err;
846
847out_drop_alg:
848 crypto_drop_aead(spawn);
849out_free_inst:
850 kfree(inst);
851 goto out;
852}
853
854static struct crypto_template crypto_rfc4309_tmpl = {
855 .name = "rfc4309",
856 .create = crypto_rfc4309_create,
857 .module = THIS_MODULE,
858};
859
860static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
861 const u8 *inkey, unsigned int keylen)
862{
863 struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
864
865 return crypto_cipher_setkey(ctx->child, inkey, keylen);
866}
867
868static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
869{
870 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
871 int bs = crypto_shash_digestsize(pdesc->tfm);
872 u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
873
874 ctx->len = 0;
875 memset(dg, 0, bs);
876
877 return 0;
878}
879
880static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
881 unsigned int len)
882{
883 struct crypto_shash *parent = pdesc->tfm;
884 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
885 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
886 struct crypto_cipher *tfm = tctx->child;
887 int bs = crypto_shash_digestsize(parent);
888 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
889
890 while (len > 0) {
891 unsigned int l = min(len, bs - ctx->len);
892
893 crypto_xor(dg + ctx->len, p, l);
894 ctx->len +=l;
895 len -= l;
896 p += l;
897
898 if (ctx->len == bs) {
899 crypto_cipher_encrypt_one(tfm, dg, dg);
900 ctx->len = 0;
901 }
902 }
903
904 return 0;
905}
906
907static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
908{
909 struct crypto_shash *parent = pdesc->tfm;
910 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
911 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
912 struct crypto_cipher *tfm = tctx->child;
913 int bs = crypto_shash_digestsize(parent);
914 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
915
916 if (ctx->len)
917 crypto_cipher_encrypt_one(tfm, dg, dg);
918
919 memcpy(out, dg, bs);
920 return 0;
921}
922
923static int cbcmac_init_tfm(struct crypto_tfm *tfm)
924{
925 struct crypto_cipher *cipher;
926 struct crypto_instance *inst = (void *)tfm->__crt_alg;
927 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
928 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
929
930 cipher = crypto_spawn_cipher(spawn);
931 if (IS_ERR(cipher))
932 return PTR_ERR(cipher);
933
934 ctx->child = cipher;
935
936 return 0;
937};
938
939static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
940{
941 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
942 crypto_free_cipher(ctx->child);
943}
944
945static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
946{
947 struct shash_instance *inst;
948 struct crypto_alg *alg;
949 int err;
950
951 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
952 if (err)
953 return err;
954
955 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
956 CRYPTO_ALG_TYPE_MASK);
957 if (IS_ERR(alg))
958 return PTR_ERR(alg);
959
960 inst = shash_alloc_instance("cbcmac", alg);
961 err = PTR_ERR(inst);
962 if (IS_ERR(inst))
963 goto out_put_alg;
964
965 err = crypto_init_spawn(shash_instance_ctx(inst), alg,
966 shash_crypto_instance(inst),
967 CRYPTO_ALG_TYPE_MASK);
968 if (err)
969 goto out_free_inst;
970
971 inst->alg.base.cra_priority = alg->cra_priority;
972 inst->alg.base.cra_blocksize = 1;
973
974 inst->alg.digestsize = alg->cra_blocksize;
975 inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
976 alg->cra_alignmask + 1) +
977 alg->cra_blocksize;
978
979 inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
980 inst->alg.base.cra_init = cbcmac_init_tfm;
981 inst->alg.base.cra_exit = cbcmac_exit_tfm;
982
983 inst->alg.init = crypto_cbcmac_digest_init;
984 inst->alg.update = crypto_cbcmac_digest_update;
985 inst->alg.final = crypto_cbcmac_digest_final;
986 inst->alg.setkey = crypto_cbcmac_digest_setkey;
987
988 err = shash_register_instance(tmpl, inst);
989
990out_free_inst:
991 if (err)
992 shash_free_instance(shash_crypto_instance(inst));
993
994out_put_alg:
995 crypto_mod_put(alg);
996 return err;
997}
998
999static struct crypto_template crypto_cbcmac_tmpl = {
1000 .name = "cbcmac",
1001 .create = cbcmac_create,
1002 .free = shash_free_instance,
1003 .module = THIS_MODULE,
1004};
1005
1006static int __init crypto_ccm_module_init(void)
1007{
1008 int err;
1009
1010 err = crypto_register_template(&crypto_cbcmac_tmpl);
1011 if (err)
1012 goto out;
1013
1014 err = crypto_register_template(&crypto_ccm_base_tmpl);
1015 if (err)
1016 goto out_undo_cbcmac;
1017
1018 err = crypto_register_template(&crypto_ccm_tmpl);
1019 if (err)
1020 goto out_undo_base;
1021
1022 err = crypto_register_template(&crypto_rfc4309_tmpl);
1023 if (err)
1024 goto out_undo_ccm;
1025
1026out:
1027 return err;
1028
1029out_undo_ccm:
1030 crypto_unregister_template(&crypto_ccm_tmpl);
1031out_undo_base:
1032 crypto_unregister_template(&crypto_ccm_base_tmpl);
1033out_undo_cbcmac:
1034 crypto_register_template(&crypto_cbcmac_tmpl);
1035 goto out;
1036}
1037
1038static void __exit crypto_ccm_module_exit(void)
1039{
1040 crypto_unregister_template(&crypto_rfc4309_tmpl);
1041 crypto_unregister_template(&crypto_ccm_tmpl);
1042 crypto_unregister_template(&crypto_ccm_base_tmpl);
1043 crypto_unregister_template(&crypto_cbcmac_tmpl);
1044}
1045
1046module_init(crypto_ccm_module_init);
1047module_exit(crypto_ccm_module_exit);
1048
1049MODULE_LICENSE("GPL");
1050MODULE_DESCRIPTION("Counter with CBC MAC");
1051MODULE_ALIAS_CRYPTO("ccm_base");
1052MODULE_ALIAS_CRYPTO("rfc4309");
1053MODULE_ALIAS_CRYPTO("ccm");