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