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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/*
2 * CCM: Counter with CBC-MAC
3 *
4 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#include <crypto/internal/aead.h>
14#include <crypto/internal/skcipher.h>
15#include <crypto/scatterwalk.h>
16#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/slab.h>
21
22#include "internal.h"
23
24struct ccm_instance_ctx {
25 struct crypto_skcipher_spawn ctr;
26 struct crypto_spawn cipher;
27};
28
29struct crypto_ccm_ctx {
30 struct crypto_cipher *cipher;
31 struct crypto_ablkcipher *ctr;
32};
33
34struct crypto_rfc4309_ctx {
35 struct crypto_aead *child;
36 u8 nonce[3];
37};
38
39struct crypto_ccm_req_priv_ctx {
40 u8 odata[16];
41 u8 idata[16];
42 u8 auth_tag[16];
43 u32 ilen;
44 u32 flags;
45 struct scatterlist src[2];
46 struct scatterlist dst[2];
47 struct ablkcipher_request abreq;
48};
49
50static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
51 struct aead_request *req)
52{
53 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
54
55 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
56}
57
58static int set_msg_len(u8 *block, unsigned int msglen, int csize)
59{
60 __be32 data;
61
62 memset(block, 0, csize);
63 block += csize;
64
65 if (csize >= 4)
66 csize = 4;
67 else if (msglen > (1 << (8 * csize)))
68 return -EOVERFLOW;
69
70 data = cpu_to_be32(msglen);
71 memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
72
73 return 0;
74}
75
76static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
77 unsigned int keylen)
78{
79 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
80 struct crypto_ablkcipher *ctr = ctx->ctr;
81 struct crypto_cipher *tfm = ctx->cipher;
82 int err = 0;
83
84 crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
85 crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
86 CRYPTO_TFM_REQ_MASK);
87 err = crypto_ablkcipher_setkey(ctr, key, keylen);
88 crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
89 CRYPTO_TFM_RES_MASK);
90 if (err)
91 goto out;
92
93 crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
94 crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) &
95 CRYPTO_TFM_REQ_MASK);
96 err = crypto_cipher_setkey(tfm, key, keylen);
97 crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) &
98 CRYPTO_TFM_RES_MASK);
99
100out:
101 return err;
102}
103
104static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
105 unsigned int authsize)
106{
107 switch (authsize) {
108 case 4:
109 case 6:
110 case 8:
111 case 10:
112 case 12:
113 case 14:
114 case 16:
115 break;
116 default:
117 return -EINVAL;
118 }
119
120 return 0;
121}
122
123static int format_input(u8 *info, struct aead_request *req,
124 unsigned int cryptlen)
125{
126 struct crypto_aead *aead = crypto_aead_reqtfm(req);
127 unsigned int lp = req->iv[0];
128 unsigned int l = lp + 1;
129 unsigned int m;
130
131 m = crypto_aead_authsize(aead);
132
133 memcpy(info, req->iv, 16);
134
135 /* format control info per RFC 3610 and
136 * NIST Special Publication 800-38C
137 */
138 *info |= (8 * ((m - 2) / 2));
139 if (req->assoclen)
140 *info |= 64;
141
142 return set_msg_len(info + 16 - l, cryptlen, l);
143}
144
145static int format_adata(u8 *adata, unsigned int a)
146{
147 int len = 0;
148
149 /* add control info for associated data
150 * RFC 3610 and NIST Special Publication 800-38C
151 */
152 if (a < 65280) {
153 *(__be16 *)adata = cpu_to_be16(a);
154 len = 2;
155 } else {
156 *(__be16 *)adata = cpu_to_be16(0xfffe);
157 *(__be32 *)&adata[2] = cpu_to_be32(a);
158 len = 6;
159 }
160
161 return len;
162}
163
164static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n,
165 struct crypto_ccm_req_priv_ctx *pctx)
166{
167 unsigned int bs = 16;
168 u8 *odata = pctx->odata;
169 u8 *idata = pctx->idata;
170 int datalen, getlen;
171
172 datalen = n;
173
174 /* first time in here, block may be partially filled. */
175 getlen = bs - pctx->ilen;
176 if (datalen >= getlen) {
177 memcpy(idata + pctx->ilen, data, getlen);
178 crypto_xor(odata, idata, bs);
179 crypto_cipher_encrypt_one(tfm, odata, odata);
180 datalen -= getlen;
181 data += getlen;
182 pctx->ilen = 0;
183 }
184
185 /* now encrypt rest of data */
186 while (datalen >= bs) {
187 crypto_xor(odata, data, bs);
188 crypto_cipher_encrypt_one(tfm, odata, odata);
189
190 datalen -= bs;
191 data += bs;
192 }
193
194 /* check and see if there's leftover data that wasn't
195 * enough to fill a block.
196 */
197 if (datalen) {
198 memcpy(idata + pctx->ilen, data, datalen);
199 pctx->ilen += datalen;
200 }
201}
202
203static void get_data_to_compute(struct crypto_cipher *tfm,
204 struct crypto_ccm_req_priv_ctx *pctx,
205 struct scatterlist *sg, unsigned int len)
206{
207 struct scatter_walk walk;
208 u8 *data_src;
209 int n;
210
211 scatterwalk_start(&walk, sg);
212
213 while (len) {
214 n = scatterwalk_clamp(&walk, len);
215 if (!n) {
216 scatterwalk_start(&walk, sg_next(walk.sg));
217 n = scatterwalk_clamp(&walk, len);
218 }
219 data_src = scatterwalk_map(&walk);
220
221 compute_mac(tfm, data_src, n, pctx);
222 len -= n;
223
224 scatterwalk_unmap(data_src);
225 scatterwalk_advance(&walk, n);
226 scatterwalk_done(&walk, 0, len);
227 if (len)
228 crypto_yield(pctx->flags);
229 }
230
231 /* any leftover needs padding and then encrypted */
232 if (pctx->ilen) {
233 int padlen;
234 u8 *odata = pctx->odata;
235 u8 *idata = pctx->idata;
236
237 padlen = 16 - pctx->ilen;
238 memset(idata + pctx->ilen, 0, padlen);
239 crypto_xor(odata, idata, 16);
240 crypto_cipher_encrypt_one(tfm, odata, odata);
241 pctx->ilen = 0;
242 }
243}
244
245static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
246 unsigned int cryptlen)
247{
248 struct crypto_aead *aead = crypto_aead_reqtfm(req);
249 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
250 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
251 struct crypto_cipher *cipher = ctx->cipher;
252 unsigned int assoclen = req->assoclen;
253 u8 *odata = pctx->odata;
254 u8 *idata = pctx->idata;
255 int err;
256
257 /* format control data for input */
258 err = format_input(odata, req, cryptlen);
259 if (err)
260 goto out;
261
262 /* encrypt first block to use as start in computing mac */
263 crypto_cipher_encrypt_one(cipher, odata, odata);
264
265 /* format associated data and compute into mac */
266 if (assoclen) {
267 pctx->ilen = format_adata(idata, assoclen);
268 get_data_to_compute(cipher, pctx, req->assoc, req->assoclen);
269 } else {
270 pctx->ilen = 0;
271 }
272
273 /* compute plaintext into mac */
274 if (cryptlen)
275 get_data_to_compute(cipher, pctx, plain, cryptlen);
276
277out:
278 return err;
279}
280
281static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
282{
283 struct aead_request *req = areq->data;
284 struct crypto_aead *aead = crypto_aead_reqtfm(req);
285 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
286 u8 *odata = pctx->odata;
287
288 if (!err)
289 scatterwalk_map_and_copy(odata, req->dst, req->cryptlen,
290 crypto_aead_authsize(aead), 1);
291 aead_request_complete(req, err);
292}
293
294static inline int crypto_ccm_check_iv(const u8 *iv)
295{
296 /* 2 <= L <= 8, so 1 <= L' <= 7. */
297 if (1 > iv[0] || iv[0] > 7)
298 return -EINVAL;
299
300 return 0;
301}
302
303static int crypto_ccm_encrypt(struct aead_request *req)
304{
305 struct crypto_aead *aead = crypto_aead_reqtfm(req);
306 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
307 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
308 struct ablkcipher_request *abreq = &pctx->abreq;
309 struct scatterlist *dst;
310 unsigned int cryptlen = req->cryptlen;
311 u8 *odata = pctx->odata;
312 u8 *iv = req->iv;
313 int err;
314
315 err = crypto_ccm_check_iv(iv);
316 if (err)
317 return err;
318
319 pctx->flags = aead_request_flags(req);
320
321 err = crypto_ccm_auth(req, req->src, cryptlen);
322 if (err)
323 return err;
324
325 /* Note: rfc 3610 and NIST 800-38C require counter of
326 * zero to encrypt auth tag.
327 */
328 memset(iv + 15 - iv[0], 0, iv[0] + 1);
329
330 sg_init_table(pctx->src, 2);
331 sg_set_buf(pctx->src, odata, 16);
332 scatterwalk_sg_chain(pctx->src, 2, req->src);
333
334 dst = pctx->src;
335 if (req->src != req->dst) {
336 sg_init_table(pctx->dst, 2);
337 sg_set_buf(pctx->dst, odata, 16);
338 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
339 dst = pctx->dst;
340 }
341
342 ablkcipher_request_set_tfm(abreq, ctx->ctr);
343 ablkcipher_request_set_callback(abreq, pctx->flags,
344 crypto_ccm_encrypt_done, req);
345 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
346 err = crypto_ablkcipher_encrypt(abreq);
347 if (err)
348 return err;
349
350 /* copy authtag to end of dst */
351 scatterwalk_map_and_copy(odata, req->dst, cryptlen,
352 crypto_aead_authsize(aead), 1);
353 return err;
354}
355
356static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
357 int err)
358{
359 struct aead_request *req = areq->data;
360 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
361 struct crypto_aead *aead = crypto_aead_reqtfm(req);
362 unsigned int authsize = crypto_aead_authsize(aead);
363 unsigned int cryptlen = req->cryptlen - authsize;
364
365 if (!err) {
366 err = crypto_ccm_auth(req, req->dst, cryptlen);
367 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
368 err = -EBADMSG;
369 }
370 aead_request_complete(req, err);
371}
372
373static int crypto_ccm_decrypt(struct aead_request *req)
374{
375 struct crypto_aead *aead = crypto_aead_reqtfm(req);
376 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
377 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
378 struct ablkcipher_request *abreq = &pctx->abreq;
379 struct scatterlist *dst;
380 unsigned int authsize = crypto_aead_authsize(aead);
381 unsigned int cryptlen = req->cryptlen;
382 u8 *authtag = pctx->auth_tag;
383 u8 *odata = pctx->odata;
384 u8 *iv = req->iv;
385 int err;
386
387 if (cryptlen < authsize)
388 return -EINVAL;
389 cryptlen -= authsize;
390
391 err = crypto_ccm_check_iv(iv);
392 if (err)
393 return err;
394
395 pctx->flags = aead_request_flags(req);
396
397 scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0);
398
399 memset(iv + 15 - iv[0], 0, iv[0] + 1);
400
401 sg_init_table(pctx->src, 2);
402 sg_set_buf(pctx->src, authtag, 16);
403 scatterwalk_sg_chain(pctx->src, 2, req->src);
404
405 dst = pctx->src;
406 if (req->src != req->dst) {
407 sg_init_table(pctx->dst, 2);
408 sg_set_buf(pctx->dst, authtag, 16);
409 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
410 dst = pctx->dst;
411 }
412
413 ablkcipher_request_set_tfm(abreq, ctx->ctr);
414 ablkcipher_request_set_callback(abreq, pctx->flags,
415 crypto_ccm_decrypt_done, req);
416 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
417 err = crypto_ablkcipher_decrypt(abreq);
418 if (err)
419 return err;
420
421 err = crypto_ccm_auth(req, req->dst, cryptlen);
422 if (err)
423 return err;
424
425 /* verify */
426 if (crypto_memneq(authtag, odata, authsize))
427 return -EBADMSG;
428
429 return err;
430}
431
432static int crypto_ccm_init_tfm(struct crypto_tfm *tfm)
433{
434 struct crypto_instance *inst = (void *)tfm->__crt_alg;
435 struct ccm_instance_ctx *ictx = crypto_instance_ctx(inst);
436 struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
437 struct crypto_cipher *cipher;
438 struct crypto_ablkcipher *ctr;
439 unsigned long align;
440 int err;
441
442 cipher = crypto_spawn_cipher(&ictx->cipher);
443 if (IS_ERR(cipher))
444 return PTR_ERR(cipher);
445
446 ctr = crypto_spawn_skcipher(&ictx->ctr);
447 err = PTR_ERR(ctr);
448 if (IS_ERR(ctr))
449 goto err_free_cipher;
450
451 ctx->cipher = cipher;
452 ctx->ctr = ctr;
453
454 align = crypto_tfm_alg_alignmask(tfm);
455 align &= ~(crypto_tfm_ctx_alignment() - 1);
456 tfm->crt_aead.reqsize = align +
457 sizeof(struct crypto_ccm_req_priv_ctx) +
458 crypto_ablkcipher_reqsize(ctr);
459
460 return 0;
461
462err_free_cipher:
463 crypto_free_cipher(cipher);
464 return err;
465}
466
467static void crypto_ccm_exit_tfm(struct crypto_tfm *tfm)
468{
469 struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
470
471 crypto_free_cipher(ctx->cipher);
472 crypto_free_ablkcipher(ctx->ctr);
473}
474
475static struct crypto_instance *crypto_ccm_alloc_common(struct rtattr **tb,
476 const char *full_name,
477 const char *ctr_name,
478 const char *cipher_name)
479{
480 struct crypto_attr_type *algt;
481 struct crypto_instance *inst;
482 struct crypto_alg *ctr;
483 struct crypto_alg *cipher;
484 struct ccm_instance_ctx *ictx;
485 int err;
486
487 algt = crypto_get_attr_type(tb);
488 if (IS_ERR(algt))
489 return ERR_CAST(algt);
490
491 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
492 return ERR_PTR(-EINVAL);
493
494 cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER,
495 CRYPTO_ALG_TYPE_MASK);
496 if (IS_ERR(cipher))
497 return ERR_CAST(cipher);
498
499 err = -EINVAL;
500 if (cipher->cra_blocksize != 16)
501 goto out_put_cipher;
502
503 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
504 err = -ENOMEM;
505 if (!inst)
506 goto out_put_cipher;
507
508 ictx = crypto_instance_ctx(inst);
509
510 err = crypto_init_spawn(&ictx->cipher, cipher, inst,
511 CRYPTO_ALG_TYPE_MASK);
512 if (err)
513 goto err_free_inst;
514
515 crypto_set_skcipher_spawn(&ictx->ctr, inst);
516 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
517 crypto_requires_sync(algt->type,
518 algt->mask));
519 if (err)
520 goto err_drop_cipher;
521
522 ctr = crypto_skcipher_spawn_alg(&ictx->ctr);
523
524 /* Not a stream cipher? */
525 err = -EINVAL;
526 if (ctr->cra_blocksize != 1)
527 goto err_drop_ctr;
528
529 /* We want the real thing! */
530 if (ctr->cra_ablkcipher.ivsize != 16)
531 goto err_drop_ctr;
532
533 err = -ENAMETOOLONG;
534 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
535 "ccm_base(%s,%s)", ctr->cra_driver_name,
536 cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
537 goto err_drop_ctr;
538
539 memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
540
541 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
542 inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
543 inst->alg.cra_priority = cipher->cra_priority + ctr->cra_priority;
544 inst->alg.cra_blocksize = 1;
545 inst->alg.cra_alignmask = cipher->cra_alignmask | ctr->cra_alignmask |
546 (__alignof__(u32) - 1);
547 inst->alg.cra_type = &crypto_aead_type;
548 inst->alg.cra_aead.ivsize = 16;
549 inst->alg.cra_aead.maxauthsize = 16;
550 inst->alg.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
551 inst->alg.cra_init = crypto_ccm_init_tfm;
552 inst->alg.cra_exit = crypto_ccm_exit_tfm;
553 inst->alg.cra_aead.setkey = crypto_ccm_setkey;
554 inst->alg.cra_aead.setauthsize = crypto_ccm_setauthsize;
555 inst->alg.cra_aead.encrypt = crypto_ccm_encrypt;
556 inst->alg.cra_aead.decrypt = crypto_ccm_decrypt;
557
558out:
559 crypto_mod_put(cipher);
560 return inst;
561
562err_drop_ctr:
563 crypto_drop_skcipher(&ictx->ctr);
564err_drop_cipher:
565 crypto_drop_spawn(&ictx->cipher);
566err_free_inst:
567 kfree(inst);
568out_put_cipher:
569 inst = ERR_PTR(err);
570 goto out;
571}
572
573static struct crypto_instance *crypto_ccm_alloc(struct rtattr **tb)
574{
575 const char *cipher_name;
576 char ctr_name[CRYPTO_MAX_ALG_NAME];
577 char full_name[CRYPTO_MAX_ALG_NAME];
578
579 cipher_name = crypto_attr_alg_name(tb[1]);
580 if (IS_ERR(cipher_name))
581 return ERR_CAST(cipher_name);
582
583 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
584 cipher_name) >= CRYPTO_MAX_ALG_NAME)
585 return ERR_PTR(-ENAMETOOLONG);
586
587 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
588 CRYPTO_MAX_ALG_NAME)
589 return ERR_PTR(-ENAMETOOLONG);
590
591 return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
592}
593
594static void crypto_ccm_free(struct crypto_instance *inst)
595{
596 struct ccm_instance_ctx *ctx = crypto_instance_ctx(inst);
597
598 crypto_drop_spawn(&ctx->cipher);
599 crypto_drop_skcipher(&ctx->ctr);
600 kfree(inst);
601}
602
603static struct crypto_template crypto_ccm_tmpl = {
604 .name = "ccm",
605 .alloc = crypto_ccm_alloc,
606 .free = crypto_ccm_free,
607 .module = THIS_MODULE,
608};
609
610static struct crypto_instance *crypto_ccm_base_alloc(struct rtattr **tb)
611{
612 const char *ctr_name;
613 const char *cipher_name;
614 char full_name[CRYPTO_MAX_ALG_NAME];
615
616 ctr_name = crypto_attr_alg_name(tb[1]);
617 if (IS_ERR(ctr_name))
618 return ERR_CAST(ctr_name);
619
620 cipher_name = crypto_attr_alg_name(tb[2]);
621 if (IS_ERR(cipher_name))
622 return ERR_CAST(cipher_name);
623
624 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
625 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
626 return ERR_PTR(-ENAMETOOLONG);
627
628 return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
629}
630
631static struct crypto_template crypto_ccm_base_tmpl = {
632 .name = "ccm_base",
633 .alloc = crypto_ccm_base_alloc,
634 .free = crypto_ccm_free,
635 .module = THIS_MODULE,
636};
637
638static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
639 unsigned int keylen)
640{
641 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
642 struct crypto_aead *child = ctx->child;
643 int err;
644
645 if (keylen < 3)
646 return -EINVAL;
647
648 keylen -= 3;
649 memcpy(ctx->nonce, key + keylen, 3);
650
651 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
652 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
653 CRYPTO_TFM_REQ_MASK);
654 err = crypto_aead_setkey(child, key, keylen);
655 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
656 CRYPTO_TFM_RES_MASK);
657
658 return err;
659}
660
661static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
662 unsigned int authsize)
663{
664 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
665
666 switch (authsize) {
667 case 8:
668 case 12:
669 case 16:
670 break;
671 default:
672 return -EINVAL;
673 }
674
675 return crypto_aead_setauthsize(ctx->child, authsize);
676}
677
678static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
679{
680 struct aead_request *subreq = aead_request_ctx(req);
681 struct crypto_aead *aead = crypto_aead_reqtfm(req);
682 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
683 struct crypto_aead *child = ctx->child;
684 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
685 crypto_aead_alignmask(child) + 1);
686
687 /* L' */
688 iv[0] = 3;
689
690 memcpy(iv + 1, ctx->nonce, 3);
691 memcpy(iv + 4, req->iv, 8);
692
693 aead_request_set_tfm(subreq, child);
694 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
695 req->base.data);
696 aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
697 aead_request_set_assoc(subreq, req->assoc, req->assoclen);
698
699 return subreq;
700}
701
702static int crypto_rfc4309_encrypt(struct aead_request *req)
703{
704 req = crypto_rfc4309_crypt(req);
705
706 return crypto_aead_encrypt(req);
707}
708
709static int crypto_rfc4309_decrypt(struct aead_request *req)
710{
711 req = crypto_rfc4309_crypt(req);
712
713 return crypto_aead_decrypt(req);
714}
715
716static int crypto_rfc4309_init_tfm(struct crypto_tfm *tfm)
717{
718 struct crypto_instance *inst = (void *)tfm->__crt_alg;
719 struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
720 struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
721 struct crypto_aead *aead;
722 unsigned long align;
723
724 aead = crypto_spawn_aead(spawn);
725 if (IS_ERR(aead))
726 return PTR_ERR(aead);
727
728 ctx->child = aead;
729
730 align = crypto_aead_alignmask(aead);
731 align &= ~(crypto_tfm_ctx_alignment() - 1);
732 tfm->crt_aead.reqsize = sizeof(struct aead_request) +
733 ALIGN(crypto_aead_reqsize(aead),
734 crypto_tfm_ctx_alignment()) +
735 align + 16;
736
737 return 0;
738}
739
740static void crypto_rfc4309_exit_tfm(struct crypto_tfm *tfm)
741{
742 struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
743
744 crypto_free_aead(ctx->child);
745}
746
747static struct crypto_instance *crypto_rfc4309_alloc(struct rtattr **tb)
748{
749 struct crypto_attr_type *algt;
750 struct crypto_instance *inst;
751 struct crypto_aead_spawn *spawn;
752 struct crypto_alg *alg;
753 const char *ccm_name;
754 int err;
755
756 algt = crypto_get_attr_type(tb);
757 if (IS_ERR(algt))
758 return ERR_CAST(algt);
759
760 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
761 return ERR_PTR(-EINVAL);
762
763 ccm_name = crypto_attr_alg_name(tb[1]);
764 if (IS_ERR(ccm_name))
765 return ERR_CAST(ccm_name);
766
767 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
768 if (!inst)
769 return ERR_PTR(-ENOMEM);
770
771 spawn = crypto_instance_ctx(inst);
772 crypto_set_aead_spawn(spawn, inst);
773 err = crypto_grab_aead(spawn, ccm_name, 0,
774 crypto_requires_sync(algt->type, algt->mask));
775 if (err)
776 goto out_free_inst;
777
778 alg = crypto_aead_spawn_alg(spawn);
779
780 err = -EINVAL;
781
782 /* We only support 16-byte blocks. */
783 if (alg->cra_aead.ivsize != 16)
784 goto out_drop_alg;
785
786 /* Not a stream cipher? */
787 if (alg->cra_blocksize != 1)
788 goto out_drop_alg;
789
790 err = -ENAMETOOLONG;
791 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
792 "rfc4309(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
793 snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
794 "rfc4309(%s)", alg->cra_driver_name) >=
795 CRYPTO_MAX_ALG_NAME)
796 goto out_drop_alg;
797
798 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
799 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
800 inst->alg.cra_priority = alg->cra_priority;
801 inst->alg.cra_blocksize = 1;
802 inst->alg.cra_alignmask = alg->cra_alignmask;
803 inst->alg.cra_type = &crypto_nivaead_type;
804
805 inst->alg.cra_aead.ivsize = 8;
806 inst->alg.cra_aead.maxauthsize = 16;
807
808 inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
809
810 inst->alg.cra_init = crypto_rfc4309_init_tfm;
811 inst->alg.cra_exit = crypto_rfc4309_exit_tfm;
812
813 inst->alg.cra_aead.setkey = crypto_rfc4309_setkey;
814 inst->alg.cra_aead.setauthsize = crypto_rfc4309_setauthsize;
815 inst->alg.cra_aead.encrypt = crypto_rfc4309_encrypt;
816 inst->alg.cra_aead.decrypt = crypto_rfc4309_decrypt;
817
818 inst->alg.cra_aead.geniv = "seqiv";
819
820out:
821 return inst;
822
823out_drop_alg:
824 crypto_drop_aead(spawn);
825out_free_inst:
826 kfree(inst);
827 inst = ERR_PTR(err);
828 goto out;
829}
830
831static void crypto_rfc4309_free(struct crypto_instance *inst)
832{
833 crypto_drop_spawn(crypto_instance_ctx(inst));
834 kfree(inst);
835}
836
837static struct crypto_template crypto_rfc4309_tmpl = {
838 .name = "rfc4309",
839 .alloc = crypto_rfc4309_alloc,
840 .free = crypto_rfc4309_free,
841 .module = THIS_MODULE,
842};
843
844static int __init crypto_ccm_module_init(void)
845{
846 int err;
847
848 err = crypto_register_template(&crypto_ccm_base_tmpl);
849 if (err)
850 goto out;
851
852 err = crypto_register_template(&crypto_ccm_tmpl);
853 if (err)
854 goto out_undo_base;
855
856 err = crypto_register_template(&crypto_rfc4309_tmpl);
857 if (err)
858 goto out_undo_ccm;
859
860out:
861 return err;
862
863out_undo_ccm:
864 crypto_unregister_template(&crypto_ccm_tmpl);
865out_undo_base:
866 crypto_unregister_template(&crypto_ccm_base_tmpl);
867 goto out;
868}
869
870static void __exit crypto_ccm_module_exit(void)
871{
872 crypto_unregister_template(&crypto_rfc4309_tmpl);
873 crypto_unregister_template(&crypto_ccm_tmpl);
874 crypto_unregister_template(&crypto_ccm_base_tmpl);
875}
876
877module_init(crypto_ccm_module_init);
878module_exit(crypto_ccm_module_exit);
879
880MODULE_LICENSE("GPL");
881MODULE_DESCRIPTION("Counter with CBC MAC");
882MODULE_ALIAS("ccm_base");
883MODULE_ALIAS("rfc4309");