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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/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_rfc4309_req_ctx {
40 struct scatterlist src[3];
41 struct scatterlist dst[3];
42 struct aead_request subreq;
43};
44
45struct crypto_ccm_req_priv_ctx {
46 u8 odata[16];
47 u8 idata[16];
48 u8 auth_tag[16];
49 u32 ilen;
50 u32 flags;
51 struct scatterlist src[3];
52 struct scatterlist dst[3];
53 struct ablkcipher_request abreq;
54};
55
56static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
57 struct aead_request *req)
58{
59 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
60
61 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
62}
63
64static int set_msg_len(u8 *block, unsigned int msglen, int csize)
65{
66 __be32 data;
67
68 memset(block, 0, csize);
69 block += csize;
70
71 if (csize >= 4)
72 csize = 4;
73 else if (msglen > (1 << (8 * csize)))
74 return -EOVERFLOW;
75
76 data = cpu_to_be32(msglen);
77 memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
78
79 return 0;
80}
81
82static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
83 unsigned int keylen)
84{
85 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
86 struct crypto_ablkcipher *ctr = ctx->ctr;
87 struct crypto_cipher *tfm = ctx->cipher;
88 int err = 0;
89
90 crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
91 crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
92 CRYPTO_TFM_REQ_MASK);
93 err = crypto_ablkcipher_setkey(ctr, key, keylen);
94 crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
95 CRYPTO_TFM_RES_MASK);
96 if (err)
97 goto out;
98
99 crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
100 crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) &
101 CRYPTO_TFM_REQ_MASK);
102 err = crypto_cipher_setkey(tfm, key, keylen);
103 crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) &
104 CRYPTO_TFM_RES_MASK);
105
106out:
107 return err;
108}
109
110static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
111 unsigned int authsize)
112{
113 switch (authsize) {
114 case 4:
115 case 6:
116 case 8:
117 case 10:
118 case 12:
119 case 14:
120 case 16:
121 break;
122 default:
123 return -EINVAL;
124 }
125
126 return 0;
127}
128
129static int format_input(u8 *info, struct aead_request *req,
130 unsigned int cryptlen)
131{
132 struct crypto_aead *aead = crypto_aead_reqtfm(req);
133 unsigned int lp = req->iv[0];
134 unsigned int l = lp + 1;
135 unsigned int m;
136
137 m = crypto_aead_authsize(aead);
138
139 memcpy(info, req->iv, 16);
140
141 /* format control info per RFC 3610 and
142 * NIST Special Publication 800-38C
143 */
144 *info |= (8 * ((m - 2) / 2));
145 if (req->assoclen)
146 *info |= 64;
147
148 return set_msg_len(info + 16 - l, cryptlen, l);
149}
150
151static int format_adata(u8 *adata, unsigned int a)
152{
153 int len = 0;
154
155 /* add control info for associated data
156 * RFC 3610 and NIST Special Publication 800-38C
157 */
158 if (a < 65280) {
159 *(__be16 *)adata = cpu_to_be16(a);
160 len = 2;
161 } else {
162 *(__be16 *)adata = cpu_to_be16(0xfffe);
163 *(__be32 *)&adata[2] = cpu_to_be32(a);
164 len = 6;
165 }
166
167 return len;
168}
169
170static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n,
171 struct crypto_ccm_req_priv_ctx *pctx)
172{
173 unsigned int bs = 16;
174 u8 *odata = pctx->odata;
175 u8 *idata = pctx->idata;
176 int datalen, getlen;
177
178 datalen = n;
179
180 /* first time in here, block may be partially filled. */
181 getlen = bs - pctx->ilen;
182 if (datalen >= getlen) {
183 memcpy(idata + pctx->ilen, data, getlen);
184 crypto_xor(odata, idata, bs);
185 crypto_cipher_encrypt_one(tfm, odata, odata);
186 datalen -= getlen;
187 data += getlen;
188 pctx->ilen = 0;
189 }
190
191 /* now encrypt rest of data */
192 while (datalen >= bs) {
193 crypto_xor(odata, data, bs);
194 crypto_cipher_encrypt_one(tfm, odata, odata);
195
196 datalen -= bs;
197 data += bs;
198 }
199
200 /* check and see if there's leftover data that wasn't
201 * enough to fill a block.
202 */
203 if (datalen) {
204 memcpy(idata + pctx->ilen, data, datalen);
205 pctx->ilen += datalen;
206 }
207}
208
209static void get_data_to_compute(struct crypto_cipher *tfm,
210 struct crypto_ccm_req_priv_ctx *pctx,
211 struct scatterlist *sg, unsigned int len)
212{
213 struct scatter_walk walk;
214 u8 *data_src;
215 int n;
216
217 scatterwalk_start(&walk, sg);
218
219 while (len) {
220 n = scatterwalk_clamp(&walk, len);
221 if (!n) {
222 scatterwalk_start(&walk, sg_next(walk.sg));
223 n = scatterwalk_clamp(&walk, len);
224 }
225 data_src = scatterwalk_map(&walk);
226
227 compute_mac(tfm, data_src, n, pctx);
228 len -= n;
229
230 scatterwalk_unmap(data_src);
231 scatterwalk_advance(&walk, n);
232 scatterwalk_done(&walk, 0, len);
233 if (len)
234 crypto_yield(pctx->flags);
235 }
236
237 /* any leftover needs padding and then encrypted */
238 if (pctx->ilen) {
239 int padlen;
240 u8 *odata = pctx->odata;
241 u8 *idata = pctx->idata;
242
243 padlen = 16 - pctx->ilen;
244 memset(idata + pctx->ilen, 0, padlen);
245 crypto_xor(odata, idata, 16);
246 crypto_cipher_encrypt_one(tfm, odata, odata);
247 pctx->ilen = 0;
248 }
249}
250
251static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
252 unsigned int cryptlen)
253{
254 struct crypto_aead *aead = crypto_aead_reqtfm(req);
255 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
256 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
257 struct crypto_cipher *cipher = ctx->cipher;
258 unsigned int assoclen = req->assoclen;
259 u8 *odata = pctx->odata;
260 u8 *idata = pctx->idata;
261 int err;
262
263 /* format control data for input */
264 err = format_input(odata, req, cryptlen);
265 if (err)
266 goto out;
267
268 /* encrypt first block to use as start in computing mac */
269 crypto_cipher_encrypt_one(cipher, odata, odata);
270
271 /* format associated data and compute into mac */
272 if (assoclen) {
273 pctx->ilen = format_adata(idata, assoclen);
274 get_data_to_compute(cipher, pctx, req->src, req->assoclen);
275 } else {
276 pctx->ilen = 0;
277 }
278
279 /* compute plaintext into mac */
280 if (cryptlen)
281 get_data_to_compute(cipher, pctx, plain, cryptlen);
282
283out:
284 return err;
285}
286
287static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
288{
289 struct aead_request *req = areq->data;
290 struct crypto_aead *aead = crypto_aead_reqtfm(req);
291 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
292 u8 *odata = pctx->odata;
293
294 if (!err)
295 scatterwalk_map_and_copy(odata, req->dst,
296 req->assoclen + req->cryptlen,
297 crypto_aead_authsize(aead), 1);
298 aead_request_complete(req, err);
299}
300
301static inline int crypto_ccm_check_iv(const u8 *iv)
302{
303 /* 2 <= L <= 8, so 1 <= L' <= 7. */
304 if (1 > iv[0] || iv[0] > 7)
305 return -EINVAL;
306
307 return 0;
308}
309
310static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
311{
312 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
313 struct scatterlist *sg;
314 u8 *iv = req->iv;
315 int err;
316
317 err = crypto_ccm_check_iv(iv);
318 if (err)
319 return err;
320
321 pctx->flags = aead_request_flags(req);
322
323 /* Note: rfc 3610 and NIST 800-38C require counter of
324 * zero to encrypt auth tag.
325 */
326 memset(iv + 15 - iv[0], 0, iv[0] + 1);
327
328 sg_init_table(pctx->src, 3);
329 sg_set_buf(pctx->src, tag, 16);
330 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
331 if (sg != pctx->src + 1)
332 sg_chain(pctx->src, 2, sg);
333
334 if (req->src != req->dst) {
335 sg_init_table(pctx->dst, 3);
336 sg_set_buf(pctx->dst, tag, 16);
337 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
338 if (sg != pctx->dst + 1)
339 sg_chain(pctx->dst, 2, sg);
340 }
341
342 return 0;
343}
344
345static int crypto_ccm_encrypt(struct aead_request *req)
346{
347 struct crypto_aead *aead = crypto_aead_reqtfm(req);
348 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
349 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
350 struct ablkcipher_request *abreq = &pctx->abreq;
351 struct scatterlist *dst;
352 unsigned int cryptlen = req->cryptlen;
353 u8 *odata = pctx->odata;
354 u8 *iv = req->iv;
355 int err;
356
357 err = crypto_ccm_init_crypt(req, odata);
358 if (err)
359 return err;
360
361 err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
362 if (err)
363 return err;
364
365 dst = pctx->src;
366 if (req->src != req->dst)
367 dst = pctx->dst;
368
369 ablkcipher_request_set_tfm(abreq, ctx->ctr);
370 ablkcipher_request_set_callback(abreq, pctx->flags,
371 crypto_ccm_encrypt_done, req);
372 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
373 err = crypto_ablkcipher_encrypt(abreq);
374 if (err)
375 return err;
376
377 /* copy authtag to end of dst */
378 scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
379 crypto_aead_authsize(aead), 1);
380 return err;
381}
382
383static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
384 int err)
385{
386 struct aead_request *req = areq->data;
387 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
388 struct crypto_aead *aead = crypto_aead_reqtfm(req);
389 unsigned int authsize = crypto_aead_authsize(aead);
390 unsigned int cryptlen = req->cryptlen - authsize;
391 struct scatterlist *dst;
392
393 pctx->flags = 0;
394
395 dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
396
397 if (!err) {
398 err = crypto_ccm_auth(req, dst, cryptlen);
399 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
400 err = -EBADMSG;
401 }
402 aead_request_complete(req, err);
403}
404
405static int crypto_ccm_decrypt(struct aead_request *req)
406{
407 struct crypto_aead *aead = crypto_aead_reqtfm(req);
408 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
409 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
410 struct ablkcipher_request *abreq = &pctx->abreq;
411 struct scatterlist *dst;
412 unsigned int authsize = crypto_aead_authsize(aead);
413 unsigned int cryptlen = req->cryptlen;
414 u8 *authtag = pctx->auth_tag;
415 u8 *odata = pctx->odata;
416 u8 *iv = req->iv;
417 int err;
418
419 cryptlen -= authsize;
420
421 err = crypto_ccm_init_crypt(req, authtag);
422 if (err)
423 return err;
424
425 scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
426 authsize, 0);
427
428 dst = pctx->src;
429 if (req->src != req->dst)
430 dst = pctx->dst;
431
432 ablkcipher_request_set_tfm(abreq, ctx->ctr);
433 ablkcipher_request_set_callback(abreq, pctx->flags,
434 crypto_ccm_decrypt_done, req);
435 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
436 err = crypto_ablkcipher_decrypt(abreq);
437 if (err)
438 return err;
439
440 err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
441 if (err)
442 return err;
443
444 /* verify */
445 if (crypto_memneq(authtag, odata, authsize))
446 return -EBADMSG;
447
448 return err;
449}
450
451static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
452{
453 struct aead_instance *inst = aead_alg_instance(tfm);
454 struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
455 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
456 struct crypto_cipher *cipher;
457 struct crypto_ablkcipher *ctr;
458 unsigned long align;
459 int err;
460
461 cipher = crypto_spawn_cipher(&ictx->cipher);
462 if (IS_ERR(cipher))
463 return PTR_ERR(cipher);
464
465 ctr = crypto_spawn_skcipher(&ictx->ctr);
466 err = PTR_ERR(ctr);
467 if (IS_ERR(ctr))
468 goto err_free_cipher;
469
470 ctx->cipher = cipher;
471 ctx->ctr = ctr;
472
473 align = crypto_aead_alignmask(tfm);
474 align &= ~(crypto_tfm_ctx_alignment() - 1);
475 crypto_aead_set_reqsize(
476 tfm,
477 align + sizeof(struct crypto_ccm_req_priv_ctx) +
478 crypto_ablkcipher_reqsize(ctr));
479
480 return 0;
481
482err_free_cipher:
483 crypto_free_cipher(cipher);
484 return err;
485}
486
487static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
488{
489 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
490
491 crypto_free_cipher(ctx->cipher);
492 crypto_free_ablkcipher(ctx->ctr);
493}
494
495static void crypto_ccm_free(struct aead_instance *inst)
496{
497 struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
498
499 crypto_drop_spawn(&ctx->cipher);
500 crypto_drop_skcipher(&ctx->ctr);
501 kfree(inst);
502}
503
504static int crypto_ccm_create_common(struct crypto_template *tmpl,
505 struct rtattr **tb,
506 const char *full_name,
507 const char *ctr_name,
508 const char *cipher_name)
509{
510 struct crypto_attr_type *algt;
511 struct aead_instance *inst;
512 struct crypto_alg *ctr;
513 struct crypto_alg *cipher;
514 struct ccm_instance_ctx *ictx;
515 int err;
516
517 algt = crypto_get_attr_type(tb);
518 if (IS_ERR(algt))
519 return PTR_ERR(algt);
520
521 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
522 return -EINVAL;
523
524 cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER,
525 CRYPTO_ALG_TYPE_MASK);
526 if (IS_ERR(cipher))
527 return PTR_ERR(cipher);
528
529 err = -EINVAL;
530 if (cipher->cra_blocksize != 16)
531 goto out_put_cipher;
532
533 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
534 err = -ENOMEM;
535 if (!inst)
536 goto out_put_cipher;
537
538 ictx = aead_instance_ctx(inst);
539
540 err = crypto_init_spawn(&ictx->cipher, cipher,
541 aead_crypto_instance(inst),
542 CRYPTO_ALG_TYPE_MASK);
543 if (err)
544 goto err_free_inst;
545
546 crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
547 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
548 crypto_requires_sync(algt->type,
549 algt->mask));
550 if (err)
551 goto err_drop_cipher;
552
553 ctr = crypto_skcipher_spawn_alg(&ictx->ctr);
554
555 /* Not a stream cipher? */
556 err = -EINVAL;
557 if (ctr->cra_blocksize != 1)
558 goto err_drop_ctr;
559
560 /* We want the real thing! */
561 if (ctr->cra_ablkcipher.ivsize != 16)
562 goto err_drop_ctr;
563
564 err = -ENAMETOOLONG;
565 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
566 "ccm_base(%s,%s)", ctr->cra_driver_name,
567 cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
568 goto err_drop_ctr;
569
570 memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
571
572 inst->alg.base.cra_flags = ctr->cra_flags & CRYPTO_ALG_ASYNC;
573 inst->alg.base.cra_priority = (cipher->cra_priority +
574 ctr->cra_priority) / 2;
575 inst->alg.base.cra_blocksize = 1;
576 inst->alg.base.cra_alignmask = cipher->cra_alignmask |
577 ctr->cra_alignmask |
578 (__alignof__(u32) - 1);
579 inst->alg.ivsize = 16;
580 inst->alg.maxauthsize = 16;
581 inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
582 inst->alg.init = crypto_ccm_init_tfm;
583 inst->alg.exit = crypto_ccm_exit_tfm;
584 inst->alg.setkey = crypto_ccm_setkey;
585 inst->alg.setauthsize = crypto_ccm_setauthsize;
586 inst->alg.encrypt = crypto_ccm_encrypt;
587 inst->alg.decrypt = crypto_ccm_decrypt;
588
589 inst->free = crypto_ccm_free;
590
591 err = aead_register_instance(tmpl, inst);
592 if (err)
593 goto err_drop_ctr;
594
595out_put_cipher:
596 crypto_mod_put(cipher);
597 return err;
598
599err_drop_ctr:
600 crypto_drop_skcipher(&ictx->ctr);
601err_drop_cipher:
602 crypto_drop_spawn(&ictx->cipher);
603err_free_inst:
604 kfree(inst);
605 goto out_put_cipher;
606}
607
608static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
609{
610 const char *cipher_name;
611 char ctr_name[CRYPTO_MAX_ALG_NAME];
612 char full_name[CRYPTO_MAX_ALG_NAME];
613
614 cipher_name = crypto_attr_alg_name(tb[1]);
615 if (IS_ERR(cipher_name))
616 return PTR_ERR(cipher_name);
617
618 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
619 cipher_name) >= CRYPTO_MAX_ALG_NAME)
620 return -ENAMETOOLONG;
621
622 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
623 CRYPTO_MAX_ALG_NAME)
624 return -ENAMETOOLONG;
625
626 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
627 cipher_name);
628}
629
630static struct crypto_template crypto_ccm_tmpl = {
631 .name = "ccm",
632 .create = crypto_ccm_create,
633 .module = THIS_MODULE,
634};
635
636static int crypto_ccm_base_create(struct crypto_template *tmpl,
637 struct rtattr **tb)
638{
639 const char *ctr_name;
640 const char *cipher_name;
641 char full_name[CRYPTO_MAX_ALG_NAME];
642
643 ctr_name = crypto_attr_alg_name(tb[1]);
644 if (IS_ERR(ctr_name))
645 return PTR_ERR(ctr_name);
646
647 cipher_name = crypto_attr_alg_name(tb[2]);
648 if (IS_ERR(cipher_name))
649 return PTR_ERR(cipher_name);
650
651 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
652 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
653 return -ENAMETOOLONG;
654
655 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
656 cipher_name);
657}
658
659static struct crypto_template crypto_ccm_base_tmpl = {
660 .name = "ccm_base",
661 .create = crypto_ccm_base_create,
662 .module = THIS_MODULE,
663};
664
665static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
666 unsigned int keylen)
667{
668 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
669 struct crypto_aead *child = ctx->child;
670 int err;
671
672 if (keylen < 3)
673 return -EINVAL;
674
675 keylen -= 3;
676 memcpy(ctx->nonce, key + keylen, 3);
677
678 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
679 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
680 CRYPTO_TFM_REQ_MASK);
681 err = crypto_aead_setkey(child, key, keylen);
682 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
683 CRYPTO_TFM_RES_MASK);
684
685 return err;
686}
687
688static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
689 unsigned int authsize)
690{
691 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
692
693 switch (authsize) {
694 case 8:
695 case 12:
696 case 16:
697 break;
698 default:
699 return -EINVAL;
700 }
701
702 return crypto_aead_setauthsize(ctx->child, authsize);
703}
704
705static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
706{
707 struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
708 struct aead_request *subreq = &rctx->subreq;
709 struct crypto_aead *aead = crypto_aead_reqtfm(req);
710 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
711 struct crypto_aead *child = ctx->child;
712 struct scatterlist *sg;
713 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
714 crypto_aead_alignmask(child) + 1);
715
716 /* L' */
717 iv[0] = 3;
718
719 memcpy(iv + 1, ctx->nonce, 3);
720 memcpy(iv + 4, req->iv, 8);
721
722 scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
723
724 sg_init_table(rctx->src, 3);
725 sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
726 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
727 if (sg != rctx->src + 1)
728 sg_chain(rctx->src, 2, sg);
729
730 if (req->src != req->dst) {
731 sg_init_table(rctx->dst, 3);
732 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
733 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
734 if (sg != rctx->dst + 1)
735 sg_chain(rctx->dst, 2, sg);
736 }
737
738 aead_request_set_tfm(subreq, child);
739 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
740 req->base.data);
741 aead_request_set_crypt(subreq, rctx->src,
742 req->src == req->dst ? rctx->src : rctx->dst,
743 req->cryptlen, iv);
744 aead_request_set_ad(subreq, req->assoclen - 8);
745
746 return subreq;
747}
748
749static int crypto_rfc4309_encrypt(struct aead_request *req)
750{
751 if (req->assoclen != 16 && req->assoclen != 20)
752 return -EINVAL;
753
754 req = crypto_rfc4309_crypt(req);
755
756 return crypto_aead_encrypt(req);
757}
758
759static int crypto_rfc4309_decrypt(struct aead_request *req)
760{
761 if (req->assoclen != 16 && req->assoclen != 20)
762 return -EINVAL;
763
764 req = crypto_rfc4309_crypt(req);
765
766 return crypto_aead_decrypt(req);
767}
768
769static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
770{
771 struct aead_instance *inst = aead_alg_instance(tfm);
772 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
773 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
774 struct crypto_aead *aead;
775 unsigned long align;
776
777 aead = crypto_spawn_aead(spawn);
778 if (IS_ERR(aead))
779 return PTR_ERR(aead);
780
781 ctx->child = aead;
782
783 align = crypto_aead_alignmask(aead);
784 align &= ~(crypto_tfm_ctx_alignment() - 1);
785 crypto_aead_set_reqsize(
786 tfm,
787 sizeof(struct crypto_rfc4309_req_ctx) +
788 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
789 align + 32);
790
791 return 0;
792}
793
794static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
795{
796 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
797
798 crypto_free_aead(ctx->child);
799}
800
801static void crypto_rfc4309_free(struct aead_instance *inst)
802{
803 crypto_drop_aead(aead_instance_ctx(inst));
804 kfree(inst);
805}
806
807static int crypto_rfc4309_create(struct crypto_template *tmpl,
808 struct rtattr **tb)
809{
810 struct crypto_attr_type *algt;
811 struct aead_instance *inst;
812 struct crypto_aead_spawn *spawn;
813 struct aead_alg *alg;
814 const char *ccm_name;
815 int err;
816
817 algt = crypto_get_attr_type(tb);
818 if (IS_ERR(algt))
819 return PTR_ERR(algt);
820
821 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
822 return -EINVAL;
823
824 ccm_name = crypto_attr_alg_name(tb[1]);
825 if (IS_ERR(ccm_name))
826 return PTR_ERR(ccm_name);
827
828 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
829 if (!inst)
830 return -ENOMEM;
831
832 spawn = aead_instance_ctx(inst);
833 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
834 err = crypto_grab_aead(spawn, ccm_name, 0,
835 crypto_requires_sync(algt->type, algt->mask));
836 if (err)
837 goto out_free_inst;
838
839 alg = crypto_spawn_aead_alg(spawn);
840
841 err = -EINVAL;
842
843 /* We only support 16-byte blocks. */
844 if (crypto_aead_alg_ivsize(alg) != 16)
845 goto out_drop_alg;
846
847 /* Not a stream cipher? */
848 if (alg->base.cra_blocksize != 1)
849 goto out_drop_alg;
850
851 err = -ENAMETOOLONG;
852 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
853 "rfc4309(%s)", alg->base.cra_name) >=
854 CRYPTO_MAX_ALG_NAME ||
855 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
856 "rfc4309(%s)", alg->base.cra_driver_name) >=
857 CRYPTO_MAX_ALG_NAME)
858 goto out_drop_alg;
859
860 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
861 inst->alg.base.cra_priority = alg->base.cra_priority;
862 inst->alg.base.cra_blocksize = 1;
863 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
864
865 inst->alg.ivsize = 8;
866 inst->alg.maxauthsize = 16;
867
868 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
869
870 inst->alg.init = crypto_rfc4309_init_tfm;
871 inst->alg.exit = crypto_rfc4309_exit_tfm;
872
873 inst->alg.setkey = crypto_rfc4309_setkey;
874 inst->alg.setauthsize = crypto_rfc4309_setauthsize;
875 inst->alg.encrypt = crypto_rfc4309_encrypt;
876 inst->alg.decrypt = crypto_rfc4309_decrypt;
877
878 inst->free = crypto_rfc4309_free;
879
880 err = aead_register_instance(tmpl, inst);
881 if (err)
882 goto out_drop_alg;
883
884out:
885 return err;
886
887out_drop_alg:
888 crypto_drop_aead(spawn);
889out_free_inst:
890 kfree(inst);
891 goto out;
892}
893
894static struct crypto_template crypto_rfc4309_tmpl = {
895 .name = "rfc4309",
896 .create = crypto_rfc4309_create,
897 .module = THIS_MODULE,
898};
899
900static int __init crypto_ccm_module_init(void)
901{
902 int err;
903
904 err = crypto_register_template(&crypto_ccm_base_tmpl);
905 if (err)
906 goto out;
907
908 err = crypto_register_template(&crypto_ccm_tmpl);
909 if (err)
910 goto out_undo_base;
911
912 err = crypto_register_template(&crypto_rfc4309_tmpl);
913 if (err)
914 goto out_undo_ccm;
915
916out:
917 return err;
918
919out_undo_ccm:
920 crypto_unregister_template(&crypto_ccm_tmpl);
921out_undo_base:
922 crypto_unregister_template(&crypto_ccm_base_tmpl);
923 goto out;
924}
925
926static void __exit crypto_ccm_module_exit(void)
927{
928 crypto_unregister_template(&crypto_rfc4309_tmpl);
929 crypto_unregister_template(&crypto_ccm_tmpl);
930 crypto_unregister_template(&crypto_ccm_base_tmpl);
931}
932
933module_init(crypto_ccm_module_init);
934module_exit(crypto_ccm_module_exit);
935
936MODULE_LICENSE("GPL");
937MODULE_DESCRIPTION("Counter with CBC MAC");
938MODULE_ALIAS_CRYPTO("ccm_base");
939MODULE_ALIAS_CRYPTO("rfc4309");
940MODULE_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_skcipher *ctr;
32};
33
34struct crypto_rfc4309_ctx {
35 struct crypto_aead *child;
36 u8 nonce[3];
37};
38
39struct crypto_rfc4309_req_ctx {
40 struct scatterlist src[3];
41 struct scatterlist dst[3];
42 struct aead_request subreq;
43};
44
45struct crypto_ccm_req_priv_ctx {
46 u8 odata[16];
47 u8 idata[16];
48 u8 auth_tag[16];
49 u32 ilen;
50 u32 flags;
51 struct scatterlist src[3];
52 struct scatterlist dst[3];
53 struct skcipher_request skreq;
54};
55
56static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
57 struct aead_request *req)
58{
59 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
60
61 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
62}
63
64static int set_msg_len(u8 *block, unsigned int msglen, int csize)
65{
66 __be32 data;
67
68 memset(block, 0, csize);
69 block += csize;
70
71 if (csize >= 4)
72 csize = 4;
73 else if (msglen > (1 << (8 * csize)))
74 return -EOVERFLOW;
75
76 data = cpu_to_be32(msglen);
77 memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
78
79 return 0;
80}
81
82static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
83 unsigned int keylen)
84{
85 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
86 struct crypto_skcipher *ctr = ctx->ctr;
87 struct crypto_cipher *tfm = ctx->cipher;
88 int err = 0;
89
90 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
91 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
92 CRYPTO_TFM_REQ_MASK);
93 err = crypto_skcipher_setkey(ctr, key, keylen);
94 crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) &
95 CRYPTO_TFM_RES_MASK);
96 if (err)
97 goto out;
98
99 crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
100 crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) &
101 CRYPTO_TFM_REQ_MASK);
102 err = crypto_cipher_setkey(tfm, key, keylen);
103 crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) &
104 CRYPTO_TFM_RES_MASK);
105
106out:
107 return err;
108}
109
110static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
111 unsigned int authsize)
112{
113 switch (authsize) {
114 case 4:
115 case 6:
116 case 8:
117 case 10:
118 case 12:
119 case 14:
120 case 16:
121 break;
122 default:
123 return -EINVAL;
124 }
125
126 return 0;
127}
128
129static int format_input(u8 *info, struct aead_request *req,
130 unsigned int cryptlen)
131{
132 struct crypto_aead *aead = crypto_aead_reqtfm(req);
133 unsigned int lp = req->iv[0];
134 unsigned int l = lp + 1;
135 unsigned int m;
136
137 m = crypto_aead_authsize(aead);
138
139 memcpy(info, req->iv, 16);
140
141 /* format control info per RFC 3610 and
142 * NIST Special Publication 800-38C
143 */
144 *info |= (8 * ((m - 2) / 2));
145 if (req->assoclen)
146 *info |= 64;
147
148 return set_msg_len(info + 16 - l, cryptlen, l);
149}
150
151static int format_adata(u8 *adata, unsigned int a)
152{
153 int len = 0;
154
155 /* add control info for associated data
156 * RFC 3610 and NIST Special Publication 800-38C
157 */
158 if (a < 65280) {
159 *(__be16 *)adata = cpu_to_be16(a);
160 len = 2;
161 } else {
162 *(__be16 *)adata = cpu_to_be16(0xfffe);
163 *(__be32 *)&adata[2] = cpu_to_be32(a);
164 len = 6;
165 }
166
167 return len;
168}
169
170static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n,
171 struct crypto_ccm_req_priv_ctx *pctx)
172{
173 unsigned int bs = 16;
174 u8 *odata = pctx->odata;
175 u8 *idata = pctx->idata;
176 int datalen, getlen;
177
178 datalen = n;
179
180 /* first time in here, block may be partially filled. */
181 getlen = bs - pctx->ilen;
182 if (datalen >= getlen) {
183 memcpy(idata + pctx->ilen, data, getlen);
184 crypto_xor(odata, idata, bs);
185 crypto_cipher_encrypt_one(tfm, odata, odata);
186 datalen -= getlen;
187 data += getlen;
188 pctx->ilen = 0;
189 }
190
191 /* now encrypt rest of data */
192 while (datalen >= bs) {
193 crypto_xor(odata, data, bs);
194 crypto_cipher_encrypt_one(tfm, odata, odata);
195
196 datalen -= bs;
197 data += bs;
198 }
199
200 /* check and see if there's leftover data that wasn't
201 * enough to fill a block.
202 */
203 if (datalen) {
204 memcpy(idata + pctx->ilen, data, datalen);
205 pctx->ilen += datalen;
206 }
207}
208
209static void get_data_to_compute(struct crypto_cipher *tfm,
210 struct crypto_ccm_req_priv_ctx *pctx,
211 struct scatterlist *sg, unsigned int len)
212{
213 struct scatter_walk walk;
214 u8 *data_src;
215 int n;
216
217 scatterwalk_start(&walk, sg);
218
219 while (len) {
220 n = scatterwalk_clamp(&walk, len);
221 if (!n) {
222 scatterwalk_start(&walk, sg_next(walk.sg));
223 n = scatterwalk_clamp(&walk, len);
224 }
225 data_src = scatterwalk_map(&walk);
226
227 compute_mac(tfm, data_src, n, pctx);
228 len -= n;
229
230 scatterwalk_unmap(data_src);
231 scatterwalk_advance(&walk, n);
232 scatterwalk_done(&walk, 0, len);
233 if (len)
234 crypto_yield(pctx->flags);
235 }
236
237 /* any leftover needs padding and then encrypted */
238 if (pctx->ilen) {
239 int padlen;
240 u8 *odata = pctx->odata;
241 u8 *idata = pctx->idata;
242
243 padlen = 16 - pctx->ilen;
244 memset(idata + pctx->ilen, 0, padlen);
245 crypto_xor(odata, idata, 16);
246 crypto_cipher_encrypt_one(tfm, odata, odata);
247 pctx->ilen = 0;
248 }
249}
250
251static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
252 unsigned int cryptlen)
253{
254 struct crypto_aead *aead = crypto_aead_reqtfm(req);
255 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
256 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
257 struct crypto_cipher *cipher = ctx->cipher;
258 unsigned int assoclen = req->assoclen;
259 u8 *odata = pctx->odata;
260 u8 *idata = pctx->idata;
261 int err;
262
263 /* format control data for input */
264 err = format_input(odata, req, cryptlen);
265 if (err)
266 goto out;
267
268 /* encrypt first block to use as start in computing mac */
269 crypto_cipher_encrypt_one(cipher, odata, odata);
270
271 /* format associated data and compute into mac */
272 if (assoclen) {
273 pctx->ilen = format_adata(idata, assoclen);
274 get_data_to_compute(cipher, pctx, req->src, req->assoclen);
275 } else {
276 pctx->ilen = 0;
277 }
278
279 /* compute plaintext into mac */
280 if (cryptlen)
281 get_data_to_compute(cipher, pctx, plain, cryptlen);
282
283out:
284 return err;
285}
286
287static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
288{
289 struct aead_request *req = areq->data;
290 struct crypto_aead *aead = crypto_aead_reqtfm(req);
291 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
292 u8 *odata = pctx->odata;
293
294 if (!err)
295 scatterwalk_map_and_copy(odata, req->dst,
296 req->assoclen + req->cryptlen,
297 crypto_aead_authsize(aead), 1);
298 aead_request_complete(req, err);
299}
300
301static inline int crypto_ccm_check_iv(const u8 *iv)
302{
303 /* 2 <= L <= 8, so 1 <= L' <= 7. */
304 if (1 > iv[0] || iv[0] > 7)
305 return -EINVAL;
306
307 return 0;
308}
309
310static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
311{
312 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
313 struct scatterlist *sg;
314 u8 *iv = req->iv;
315 int err;
316
317 err = crypto_ccm_check_iv(iv);
318 if (err)
319 return err;
320
321 pctx->flags = aead_request_flags(req);
322
323 /* Note: rfc 3610 and NIST 800-38C require counter of
324 * zero to encrypt auth tag.
325 */
326 memset(iv + 15 - iv[0], 0, iv[0] + 1);
327
328 sg_init_table(pctx->src, 3);
329 sg_set_buf(pctx->src, tag, 16);
330 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
331 if (sg != pctx->src + 1)
332 sg_chain(pctx->src, 2, sg);
333
334 if (req->src != req->dst) {
335 sg_init_table(pctx->dst, 3);
336 sg_set_buf(pctx->dst, tag, 16);
337 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
338 if (sg != pctx->dst + 1)
339 sg_chain(pctx->dst, 2, sg);
340 }
341
342 return 0;
343}
344
345static int crypto_ccm_encrypt(struct aead_request *req)
346{
347 struct crypto_aead *aead = crypto_aead_reqtfm(req);
348 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
349 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
350 struct skcipher_request *skreq = &pctx->skreq;
351 struct scatterlist *dst;
352 unsigned int cryptlen = req->cryptlen;
353 u8 *odata = pctx->odata;
354 u8 *iv = req->iv;
355 int err;
356
357 err = crypto_ccm_init_crypt(req, odata);
358 if (err)
359 return err;
360
361 err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
362 if (err)
363 return err;
364
365 dst = pctx->src;
366 if (req->src != req->dst)
367 dst = pctx->dst;
368
369 skcipher_request_set_tfm(skreq, ctx->ctr);
370 skcipher_request_set_callback(skreq, pctx->flags,
371 crypto_ccm_encrypt_done, req);
372 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
373 err = crypto_skcipher_encrypt(skreq);
374 if (err)
375 return err;
376
377 /* copy authtag to end of dst */
378 scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
379 crypto_aead_authsize(aead), 1);
380 return err;
381}
382
383static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
384 int err)
385{
386 struct aead_request *req = areq->data;
387 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
388 struct crypto_aead *aead = crypto_aead_reqtfm(req);
389 unsigned int authsize = crypto_aead_authsize(aead);
390 unsigned int cryptlen = req->cryptlen - authsize;
391 struct scatterlist *dst;
392
393 pctx->flags = 0;
394
395 dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
396
397 if (!err) {
398 err = crypto_ccm_auth(req, dst, cryptlen);
399 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
400 err = -EBADMSG;
401 }
402 aead_request_complete(req, err);
403}
404
405static int crypto_ccm_decrypt(struct aead_request *req)
406{
407 struct crypto_aead *aead = crypto_aead_reqtfm(req);
408 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
409 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
410 struct skcipher_request *skreq = &pctx->skreq;
411 struct scatterlist *dst;
412 unsigned int authsize = crypto_aead_authsize(aead);
413 unsigned int cryptlen = req->cryptlen;
414 u8 *authtag = pctx->auth_tag;
415 u8 *odata = pctx->odata;
416 u8 *iv = req->iv;
417 int err;
418
419 cryptlen -= authsize;
420
421 err = crypto_ccm_init_crypt(req, authtag);
422 if (err)
423 return err;
424
425 scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
426 authsize, 0);
427
428 dst = pctx->src;
429 if (req->src != req->dst)
430 dst = pctx->dst;
431
432 skcipher_request_set_tfm(skreq, ctx->ctr);
433 skcipher_request_set_callback(skreq, pctx->flags,
434 crypto_ccm_decrypt_done, req);
435 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
436 err = crypto_skcipher_decrypt(skreq);
437 if (err)
438 return err;
439
440 err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
441 if (err)
442 return err;
443
444 /* verify */
445 if (crypto_memneq(authtag, odata, authsize))
446 return -EBADMSG;
447
448 return err;
449}
450
451static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
452{
453 struct aead_instance *inst = aead_alg_instance(tfm);
454 struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
455 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
456 struct crypto_cipher *cipher;
457 struct crypto_skcipher *ctr;
458 unsigned long align;
459 int err;
460
461 cipher = crypto_spawn_cipher(&ictx->cipher);
462 if (IS_ERR(cipher))
463 return PTR_ERR(cipher);
464
465 ctr = crypto_spawn_skcipher(&ictx->ctr);
466 err = PTR_ERR(ctr);
467 if (IS_ERR(ctr))
468 goto err_free_cipher;
469
470 ctx->cipher = cipher;
471 ctx->ctr = ctr;
472
473 align = crypto_aead_alignmask(tfm);
474 align &= ~(crypto_tfm_ctx_alignment() - 1);
475 crypto_aead_set_reqsize(
476 tfm,
477 align + sizeof(struct crypto_ccm_req_priv_ctx) +
478 crypto_skcipher_reqsize(ctr));
479
480 return 0;
481
482err_free_cipher:
483 crypto_free_cipher(cipher);
484 return err;
485}
486
487static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
488{
489 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
490
491 crypto_free_cipher(ctx->cipher);
492 crypto_free_skcipher(ctx->ctr);
493}
494
495static void crypto_ccm_free(struct aead_instance *inst)
496{
497 struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
498
499 crypto_drop_spawn(&ctx->cipher);
500 crypto_drop_skcipher(&ctx->ctr);
501 kfree(inst);
502}
503
504static int crypto_ccm_create_common(struct crypto_template *tmpl,
505 struct rtattr **tb,
506 const char *full_name,
507 const char *ctr_name,
508 const char *cipher_name)
509{
510 struct crypto_attr_type *algt;
511 struct aead_instance *inst;
512 struct skcipher_alg *ctr;
513 struct crypto_alg *cipher;
514 struct ccm_instance_ctx *ictx;
515 int err;
516
517 algt = crypto_get_attr_type(tb);
518 if (IS_ERR(algt))
519 return PTR_ERR(algt);
520
521 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
522 return -EINVAL;
523
524 cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER,
525 CRYPTO_ALG_TYPE_MASK);
526 if (IS_ERR(cipher))
527 return PTR_ERR(cipher);
528
529 err = -EINVAL;
530 if (cipher->cra_blocksize != 16)
531 goto out_put_cipher;
532
533 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
534 err = -ENOMEM;
535 if (!inst)
536 goto out_put_cipher;
537
538 ictx = aead_instance_ctx(inst);
539
540 err = crypto_init_spawn(&ictx->cipher, cipher,
541 aead_crypto_instance(inst),
542 CRYPTO_ALG_TYPE_MASK);
543 if (err)
544 goto err_free_inst;
545
546 crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
547 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
548 crypto_requires_sync(algt->type,
549 algt->mask));
550 if (err)
551 goto err_drop_cipher;
552
553 ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
554
555 /* Not a stream cipher? */
556 err = -EINVAL;
557 if (ctr->base.cra_blocksize != 1)
558 goto err_drop_ctr;
559
560 /* We want the real thing! */
561 if (crypto_skcipher_alg_ivsize(ctr) != 16)
562 goto err_drop_ctr;
563
564 err = -ENAMETOOLONG;
565 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
566 "ccm_base(%s,%s)", ctr->base.cra_driver_name,
567 cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
568 goto err_drop_ctr;
569
570 memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
571
572 inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
573 inst->alg.base.cra_priority = (cipher->cra_priority +
574 ctr->base.cra_priority) / 2;
575 inst->alg.base.cra_blocksize = 1;
576 inst->alg.base.cra_alignmask = cipher->cra_alignmask |
577 ctr->base.cra_alignmask |
578 (__alignof__(u32) - 1);
579 inst->alg.ivsize = 16;
580 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
581 inst->alg.maxauthsize = 16;
582 inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
583 inst->alg.init = crypto_ccm_init_tfm;
584 inst->alg.exit = crypto_ccm_exit_tfm;
585 inst->alg.setkey = crypto_ccm_setkey;
586 inst->alg.setauthsize = crypto_ccm_setauthsize;
587 inst->alg.encrypt = crypto_ccm_encrypt;
588 inst->alg.decrypt = crypto_ccm_decrypt;
589
590 inst->free = crypto_ccm_free;
591
592 err = aead_register_instance(tmpl, inst);
593 if (err)
594 goto err_drop_ctr;
595
596out_put_cipher:
597 crypto_mod_put(cipher);
598 return err;
599
600err_drop_ctr:
601 crypto_drop_skcipher(&ictx->ctr);
602err_drop_cipher:
603 crypto_drop_spawn(&ictx->cipher);
604err_free_inst:
605 kfree(inst);
606 goto out_put_cipher;
607}
608
609static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
610{
611 const char *cipher_name;
612 char ctr_name[CRYPTO_MAX_ALG_NAME];
613 char full_name[CRYPTO_MAX_ALG_NAME];
614
615 cipher_name = crypto_attr_alg_name(tb[1]);
616 if (IS_ERR(cipher_name))
617 return PTR_ERR(cipher_name);
618
619 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
620 cipher_name) >= CRYPTO_MAX_ALG_NAME)
621 return -ENAMETOOLONG;
622
623 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
624 CRYPTO_MAX_ALG_NAME)
625 return -ENAMETOOLONG;
626
627 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
628 cipher_name);
629}
630
631static struct crypto_template crypto_ccm_tmpl = {
632 .name = "ccm",
633 .create = crypto_ccm_create,
634 .module = THIS_MODULE,
635};
636
637static int crypto_ccm_base_create(struct crypto_template *tmpl,
638 struct rtattr **tb)
639{
640 const char *ctr_name;
641 const char *cipher_name;
642 char full_name[CRYPTO_MAX_ALG_NAME];
643
644 ctr_name = crypto_attr_alg_name(tb[1]);
645 if (IS_ERR(ctr_name))
646 return PTR_ERR(ctr_name);
647
648 cipher_name = crypto_attr_alg_name(tb[2]);
649 if (IS_ERR(cipher_name))
650 return PTR_ERR(cipher_name);
651
652 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
653 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
654 return -ENAMETOOLONG;
655
656 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
657 cipher_name);
658}
659
660static struct crypto_template crypto_ccm_base_tmpl = {
661 .name = "ccm_base",
662 .create = crypto_ccm_base_create,
663 .module = THIS_MODULE,
664};
665
666static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
667 unsigned int keylen)
668{
669 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
670 struct crypto_aead *child = ctx->child;
671 int err;
672
673 if (keylen < 3)
674 return -EINVAL;
675
676 keylen -= 3;
677 memcpy(ctx->nonce, key + keylen, 3);
678
679 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
680 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
681 CRYPTO_TFM_REQ_MASK);
682 err = crypto_aead_setkey(child, key, keylen);
683 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
684 CRYPTO_TFM_RES_MASK);
685
686 return err;
687}
688
689static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
690 unsigned int authsize)
691{
692 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
693
694 switch (authsize) {
695 case 8:
696 case 12:
697 case 16:
698 break;
699 default:
700 return -EINVAL;
701 }
702
703 return crypto_aead_setauthsize(ctx->child, authsize);
704}
705
706static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
707{
708 struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
709 struct aead_request *subreq = &rctx->subreq;
710 struct crypto_aead *aead = crypto_aead_reqtfm(req);
711 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
712 struct crypto_aead *child = ctx->child;
713 struct scatterlist *sg;
714 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
715 crypto_aead_alignmask(child) + 1);
716
717 /* L' */
718 iv[0] = 3;
719
720 memcpy(iv + 1, ctx->nonce, 3);
721 memcpy(iv + 4, req->iv, 8);
722
723 scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
724
725 sg_init_table(rctx->src, 3);
726 sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
727 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
728 if (sg != rctx->src + 1)
729 sg_chain(rctx->src, 2, sg);
730
731 if (req->src != req->dst) {
732 sg_init_table(rctx->dst, 3);
733 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
734 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
735 if (sg != rctx->dst + 1)
736 sg_chain(rctx->dst, 2, sg);
737 }
738
739 aead_request_set_tfm(subreq, child);
740 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
741 req->base.data);
742 aead_request_set_crypt(subreq, rctx->src,
743 req->src == req->dst ? rctx->src : rctx->dst,
744 req->cryptlen, iv);
745 aead_request_set_ad(subreq, req->assoclen - 8);
746
747 return subreq;
748}
749
750static int crypto_rfc4309_encrypt(struct aead_request *req)
751{
752 if (req->assoclen != 16 && req->assoclen != 20)
753 return -EINVAL;
754
755 req = crypto_rfc4309_crypt(req);
756
757 return crypto_aead_encrypt(req);
758}
759
760static int crypto_rfc4309_decrypt(struct aead_request *req)
761{
762 if (req->assoclen != 16 && req->assoclen != 20)
763 return -EINVAL;
764
765 req = crypto_rfc4309_crypt(req);
766
767 return crypto_aead_decrypt(req);
768}
769
770static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
771{
772 struct aead_instance *inst = aead_alg_instance(tfm);
773 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
774 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
775 struct crypto_aead *aead;
776 unsigned long align;
777
778 aead = crypto_spawn_aead(spawn);
779 if (IS_ERR(aead))
780 return PTR_ERR(aead);
781
782 ctx->child = aead;
783
784 align = crypto_aead_alignmask(aead);
785 align &= ~(crypto_tfm_ctx_alignment() - 1);
786 crypto_aead_set_reqsize(
787 tfm,
788 sizeof(struct crypto_rfc4309_req_ctx) +
789 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
790 align + 32);
791
792 return 0;
793}
794
795static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
796{
797 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
798
799 crypto_free_aead(ctx->child);
800}
801
802static void crypto_rfc4309_free(struct aead_instance *inst)
803{
804 crypto_drop_aead(aead_instance_ctx(inst));
805 kfree(inst);
806}
807
808static int crypto_rfc4309_create(struct crypto_template *tmpl,
809 struct rtattr **tb)
810{
811 struct crypto_attr_type *algt;
812 struct aead_instance *inst;
813 struct crypto_aead_spawn *spawn;
814 struct aead_alg *alg;
815 const char *ccm_name;
816 int err;
817
818 algt = crypto_get_attr_type(tb);
819 if (IS_ERR(algt))
820 return PTR_ERR(algt);
821
822 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
823 return -EINVAL;
824
825 ccm_name = crypto_attr_alg_name(tb[1]);
826 if (IS_ERR(ccm_name))
827 return PTR_ERR(ccm_name);
828
829 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
830 if (!inst)
831 return -ENOMEM;
832
833 spawn = aead_instance_ctx(inst);
834 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
835 err = crypto_grab_aead(spawn, ccm_name, 0,
836 crypto_requires_sync(algt->type, algt->mask));
837 if (err)
838 goto out_free_inst;
839
840 alg = crypto_spawn_aead_alg(spawn);
841
842 err = -EINVAL;
843
844 /* We only support 16-byte blocks. */
845 if (crypto_aead_alg_ivsize(alg) != 16)
846 goto out_drop_alg;
847
848 /* Not a stream cipher? */
849 if (alg->base.cra_blocksize != 1)
850 goto out_drop_alg;
851
852 err = -ENAMETOOLONG;
853 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
854 "rfc4309(%s)", alg->base.cra_name) >=
855 CRYPTO_MAX_ALG_NAME ||
856 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
857 "rfc4309(%s)", alg->base.cra_driver_name) >=
858 CRYPTO_MAX_ALG_NAME)
859 goto out_drop_alg;
860
861 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
862 inst->alg.base.cra_priority = alg->base.cra_priority;
863 inst->alg.base.cra_blocksize = 1;
864 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
865
866 inst->alg.ivsize = 8;
867 inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
868 inst->alg.maxauthsize = 16;
869
870 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
871
872 inst->alg.init = crypto_rfc4309_init_tfm;
873 inst->alg.exit = crypto_rfc4309_exit_tfm;
874
875 inst->alg.setkey = crypto_rfc4309_setkey;
876 inst->alg.setauthsize = crypto_rfc4309_setauthsize;
877 inst->alg.encrypt = crypto_rfc4309_encrypt;
878 inst->alg.decrypt = crypto_rfc4309_decrypt;
879
880 inst->free = crypto_rfc4309_free;
881
882 err = aead_register_instance(tmpl, inst);
883 if (err)
884 goto out_drop_alg;
885
886out:
887 return err;
888
889out_drop_alg:
890 crypto_drop_aead(spawn);
891out_free_inst:
892 kfree(inst);
893 goto out;
894}
895
896static struct crypto_template crypto_rfc4309_tmpl = {
897 .name = "rfc4309",
898 .create = crypto_rfc4309_create,
899 .module = THIS_MODULE,
900};
901
902static int __init crypto_ccm_module_init(void)
903{
904 int err;
905
906 err = crypto_register_template(&crypto_ccm_base_tmpl);
907 if (err)
908 goto out;
909
910 err = crypto_register_template(&crypto_ccm_tmpl);
911 if (err)
912 goto out_undo_base;
913
914 err = crypto_register_template(&crypto_rfc4309_tmpl);
915 if (err)
916 goto out_undo_ccm;
917
918out:
919 return err;
920
921out_undo_ccm:
922 crypto_unregister_template(&crypto_ccm_tmpl);
923out_undo_base:
924 crypto_unregister_template(&crypto_ccm_base_tmpl);
925 goto out;
926}
927
928static void __exit crypto_ccm_module_exit(void)
929{
930 crypto_unregister_template(&crypto_rfc4309_tmpl);
931 crypto_unregister_template(&crypto_ccm_tmpl);
932 crypto_unregister_template(&crypto_ccm_base_tmpl);
933}
934
935module_init(crypto_ccm_module_init);
936module_exit(crypto_ccm_module_exit);
937
938MODULE_LICENSE("GPL");
939MODULE_DESCRIPTION("Counter with CBC MAC");
940MODULE_ALIAS_CRYPTO("ccm_base");
941MODULE_ALIAS_CRYPTO("rfc4309");
942MODULE_ALIAS_CRYPTO("ccm");