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