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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/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);