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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * CCM: Counter with CBC-MAC
4 *
5 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
6 */
7
8#include <crypto/internal/aead.h>
9#include <crypto/internal/hash.h>
10#include <crypto/internal/skcipher.h>
11#include <crypto/scatterwalk.h>
12#include <linux/err.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17
18#include "internal.h"
19
20struct ccm_instance_ctx {
21 struct crypto_skcipher_spawn ctr;
22 struct crypto_ahash_spawn mac;
23};
24
25struct crypto_ccm_ctx {
26 struct crypto_ahash *mac;
27 struct crypto_skcipher *ctr;
28};
29
30struct crypto_rfc4309_ctx {
31 struct crypto_aead *child;
32 u8 nonce[3];
33};
34
35struct crypto_rfc4309_req_ctx {
36 struct scatterlist src[3];
37 struct scatterlist dst[3];
38 struct aead_request subreq;
39};
40
41struct crypto_ccm_req_priv_ctx {
42 u8 odata[16];
43 u8 idata[16];
44 u8 auth_tag[16];
45 u32 flags;
46 struct scatterlist src[3];
47 struct scatterlist dst[3];
48 union {
49 struct ahash_request ahreq;
50 struct skcipher_request skreq;
51 };
52};
53
54struct cbcmac_tfm_ctx {
55 struct crypto_cipher *child;
56};
57
58struct cbcmac_desc_ctx {
59 unsigned int len;
60};
61
62static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
63 struct aead_request *req)
64{
65 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
66
67 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
68}
69
70static int set_msg_len(u8 *block, unsigned int msglen, int csize)
71{
72 __be32 data;
73
74 memset(block, 0, csize);
75 block += csize;
76
77 if (csize >= 4)
78 csize = 4;
79 else if (msglen > (1 << (8 * csize)))
80 return -EOVERFLOW;
81
82 data = cpu_to_be32(msglen);
83 memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
84
85 return 0;
86}
87
88static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
89 unsigned int keylen)
90{
91 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
92 struct crypto_skcipher *ctr = ctx->ctr;
93 struct crypto_ahash *mac = ctx->mac;
94 int err = 0;
95
96 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
97 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
98 CRYPTO_TFM_REQ_MASK);
99 err = crypto_skcipher_setkey(ctr, key, keylen);
100 crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) &
101 CRYPTO_TFM_RES_MASK);
102 if (err)
103 goto out;
104
105 crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
106 crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
107 CRYPTO_TFM_REQ_MASK);
108 err = crypto_ahash_setkey(mac, key, keylen);
109 crypto_aead_set_flags(aead, crypto_ahash_get_flags(mac) &
110 CRYPTO_TFM_RES_MASK);
111
112out:
113 return err;
114}
115
116static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
117 unsigned int authsize)
118{
119 switch (authsize) {
120 case 4:
121 case 6:
122 case 8:
123 case 10:
124 case 12:
125 case 14:
126 case 16:
127 break;
128 default:
129 return -EINVAL;
130 }
131
132 return 0;
133}
134
135static int format_input(u8 *info, struct aead_request *req,
136 unsigned int cryptlen)
137{
138 struct crypto_aead *aead = crypto_aead_reqtfm(req);
139 unsigned int lp = req->iv[0];
140 unsigned int l = lp + 1;
141 unsigned int m;
142
143 m = crypto_aead_authsize(aead);
144
145 memcpy(info, req->iv, 16);
146
147 /* format control info per RFC 3610 and
148 * NIST Special Publication 800-38C
149 */
150 *info |= (8 * ((m - 2) / 2));
151 if (req->assoclen)
152 *info |= 64;
153
154 return set_msg_len(info + 16 - l, cryptlen, l);
155}
156
157static int format_adata(u8 *adata, unsigned int a)
158{
159 int len = 0;
160
161 /* add control info for associated data
162 * RFC 3610 and NIST Special Publication 800-38C
163 */
164 if (a < 65280) {
165 *(__be16 *)adata = cpu_to_be16(a);
166 len = 2;
167 } else {
168 *(__be16 *)adata = cpu_to_be16(0xfffe);
169 *(__be32 *)&adata[2] = cpu_to_be32(a);
170 len = 6;
171 }
172
173 return len;
174}
175
176static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
177 unsigned int cryptlen)
178{
179 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
180 struct crypto_aead *aead = crypto_aead_reqtfm(req);
181 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
182 struct ahash_request *ahreq = &pctx->ahreq;
183 unsigned int assoclen = req->assoclen;
184 struct scatterlist sg[3];
185 u8 *odata = pctx->odata;
186 u8 *idata = pctx->idata;
187 int ilen, err;
188
189 /* format control data for input */
190 err = format_input(odata, req, cryptlen);
191 if (err)
192 goto out;
193
194 sg_init_table(sg, 3);
195 sg_set_buf(&sg[0], odata, 16);
196
197 /* format associated data and compute into mac */
198 if (assoclen) {
199 ilen = format_adata(idata, assoclen);
200 sg_set_buf(&sg[1], idata, ilen);
201 sg_chain(sg, 3, req->src);
202 } else {
203 ilen = 0;
204 sg_chain(sg, 2, req->src);
205 }
206
207 ahash_request_set_tfm(ahreq, ctx->mac);
208 ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
209 ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
210 err = crypto_ahash_init(ahreq);
211 if (err)
212 goto out;
213 err = crypto_ahash_update(ahreq);
214 if (err)
215 goto out;
216
217 /* we need to pad the MAC input to a round multiple of the block size */
218 ilen = 16 - (assoclen + ilen) % 16;
219 if (ilen < 16) {
220 memset(idata, 0, ilen);
221 sg_init_table(sg, 2);
222 sg_set_buf(&sg[0], idata, ilen);
223 if (plain)
224 sg_chain(sg, 2, plain);
225 plain = sg;
226 cryptlen += ilen;
227 }
228
229 ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
230 err = crypto_ahash_finup(ahreq);
231out:
232 return err;
233}
234
235static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
236{
237 struct aead_request *req = areq->data;
238 struct crypto_aead *aead = crypto_aead_reqtfm(req);
239 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
240 u8 *odata = pctx->odata;
241
242 if (!err)
243 scatterwalk_map_and_copy(odata, req->dst,
244 req->assoclen + req->cryptlen,
245 crypto_aead_authsize(aead), 1);
246 aead_request_complete(req, err);
247}
248
249static inline int crypto_ccm_check_iv(const u8 *iv)
250{
251 /* 2 <= L <= 8, so 1 <= L' <= 7. */
252 if (1 > iv[0] || iv[0] > 7)
253 return -EINVAL;
254
255 return 0;
256}
257
258static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
259{
260 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
261 struct scatterlist *sg;
262 u8 *iv = req->iv;
263 int err;
264
265 err = crypto_ccm_check_iv(iv);
266 if (err)
267 return err;
268
269 pctx->flags = aead_request_flags(req);
270
271 /* Note: rfc 3610 and NIST 800-38C require counter of
272 * zero to encrypt auth tag.
273 */
274 memset(iv + 15 - iv[0], 0, iv[0] + 1);
275
276 sg_init_table(pctx->src, 3);
277 sg_set_buf(pctx->src, tag, 16);
278 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
279 if (sg != pctx->src + 1)
280 sg_chain(pctx->src, 2, sg);
281
282 if (req->src != req->dst) {
283 sg_init_table(pctx->dst, 3);
284 sg_set_buf(pctx->dst, tag, 16);
285 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
286 if (sg != pctx->dst + 1)
287 sg_chain(pctx->dst, 2, sg);
288 }
289
290 return 0;
291}
292
293static int crypto_ccm_encrypt(struct aead_request *req)
294{
295 struct crypto_aead *aead = crypto_aead_reqtfm(req);
296 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
297 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
298 struct skcipher_request *skreq = &pctx->skreq;
299 struct scatterlist *dst;
300 unsigned int cryptlen = req->cryptlen;
301 u8 *odata = pctx->odata;
302 u8 *iv = req->iv;
303 int err;
304
305 err = crypto_ccm_init_crypt(req, odata);
306 if (err)
307 return err;
308
309 err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
310 if (err)
311 return err;
312
313 dst = pctx->src;
314 if (req->src != req->dst)
315 dst = pctx->dst;
316
317 skcipher_request_set_tfm(skreq, ctx->ctr);
318 skcipher_request_set_callback(skreq, pctx->flags,
319 crypto_ccm_encrypt_done, req);
320 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
321 err = crypto_skcipher_encrypt(skreq);
322 if (err)
323 return err;
324
325 /* copy authtag to end of dst */
326 scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
327 crypto_aead_authsize(aead), 1);
328 return err;
329}
330
331static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
332 int err)
333{
334 struct aead_request *req = areq->data;
335 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
336 struct crypto_aead *aead = crypto_aead_reqtfm(req);
337 unsigned int authsize = crypto_aead_authsize(aead);
338 unsigned int cryptlen = req->cryptlen - authsize;
339 struct scatterlist *dst;
340
341 pctx->flags = 0;
342
343 dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
344
345 if (!err) {
346 err = crypto_ccm_auth(req, dst, cryptlen);
347 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
348 err = -EBADMSG;
349 }
350 aead_request_complete(req, err);
351}
352
353static int crypto_ccm_decrypt(struct aead_request *req)
354{
355 struct crypto_aead *aead = crypto_aead_reqtfm(req);
356 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
357 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
358 struct skcipher_request *skreq = &pctx->skreq;
359 struct scatterlist *dst;
360 unsigned int authsize = crypto_aead_authsize(aead);
361 unsigned int cryptlen = req->cryptlen;
362 u8 *authtag = pctx->auth_tag;
363 u8 *odata = pctx->odata;
364 u8 *iv = pctx->idata;
365 int err;
366
367 cryptlen -= authsize;
368
369 err = crypto_ccm_init_crypt(req, authtag);
370 if (err)
371 return err;
372
373 scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
374 authsize, 0);
375
376 dst = pctx->src;
377 if (req->src != req->dst)
378 dst = pctx->dst;
379
380 memcpy(iv, req->iv, 16);
381
382 skcipher_request_set_tfm(skreq, ctx->ctr);
383 skcipher_request_set_callback(skreq, pctx->flags,
384 crypto_ccm_decrypt_done, req);
385 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
386 err = crypto_skcipher_decrypt(skreq);
387 if (err)
388 return err;
389
390 err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
391 if (err)
392 return err;
393
394 /* verify */
395 if (crypto_memneq(authtag, odata, authsize))
396 return -EBADMSG;
397
398 return err;
399}
400
401static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
402{
403 struct aead_instance *inst = aead_alg_instance(tfm);
404 struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
405 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
406 struct crypto_ahash *mac;
407 struct crypto_skcipher *ctr;
408 unsigned long align;
409 int err;
410
411 mac = crypto_spawn_ahash(&ictx->mac);
412 if (IS_ERR(mac))
413 return PTR_ERR(mac);
414
415 ctr = crypto_spawn_skcipher(&ictx->ctr);
416 err = PTR_ERR(ctr);
417 if (IS_ERR(ctr))
418 goto err_free_mac;
419
420 ctx->mac = mac;
421 ctx->ctr = ctr;
422
423 align = crypto_aead_alignmask(tfm);
424 align &= ~(crypto_tfm_ctx_alignment() - 1);
425 crypto_aead_set_reqsize(
426 tfm,
427 align + sizeof(struct crypto_ccm_req_priv_ctx) +
428 max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));
429
430 return 0;
431
432err_free_mac:
433 crypto_free_ahash(mac);
434 return err;
435}
436
437static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
438{
439 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
440
441 crypto_free_ahash(ctx->mac);
442 crypto_free_skcipher(ctx->ctr);
443}
444
445static void crypto_ccm_free(struct aead_instance *inst)
446{
447 struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
448
449 crypto_drop_ahash(&ctx->mac);
450 crypto_drop_skcipher(&ctx->ctr);
451 kfree(inst);
452}
453
454static int crypto_ccm_create_common(struct crypto_template *tmpl,
455 struct rtattr **tb,
456 const char *ctr_name,
457 const char *mac_name)
458{
459 struct crypto_attr_type *algt;
460 struct aead_instance *inst;
461 struct skcipher_alg *ctr;
462 struct crypto_alg *mac_alg;
463 struct hash_alg_common *mac;
464 struct ccm_instance_ctx *ictx;
465 int err;
466
467 algt = crypto_get_attr_type(tb);
468 if (IS_ERR(algt))
469 return PTR_ERR(algt);
470
471 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
472 return -EINVAL;
473
474 mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type,
475 CRYPTO_ALG_TYPE_HASH,
476 CRYPTO_ALG_TYPE_AHASH_MASK |
477 CRYPTO_ALG_ASYNC);
478 if (IS_ERR(mac_alg))
479 return PTR_ERR(mac_alg);
480
481 mac = __crypto_hash_alg_common(mac_alg);
482 err = -EINVAL;
483 if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
484 mac->digestsize != 16)
485 goto out_put_mac;
486
487 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
488 err = -ENOMEM;
489 if (!inst)
490 goto out_put_mac;
491
492 ictx = aead_instance_ctx(inst);
493 err = crypto_init_ahash_spawn(&ictx->mac, mac,
494 aead_crypto_instance(inst));
495 if (err)
496 goto err_free_inst;
497
498 crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
499 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
500 crypto_requires_sync(algt->type,
501 algt->mask));
502 if (err)
503 goto err_drop_mac;
504
505 ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
506
507 /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
508 err = -EINVAL;
509 if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
510 crypto_skcipher_alg_ivsize(ctr) != 16 ||
511 ctr->base.cra_blocksize != 1)
512 goto err_drop_ctr;
513
514 /* ctr and cbcmac must use the same underlying block cipher. */
515 if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
516 goto err_drop_ctr;
517
518 err = -ENAMETOOLONG;
519 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
520 "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
521 goto err_drop_ctr;
522
523 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
524 "ccm_base(%s,%s)", ctr->base.cra_driver_name,
525 mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
526 goto err_drop_ctr;
527
528 inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
529 inst->alg.base.cra_priority = (mac->base.cra_priority +
530 ctr->base.cra_priority) / 2;
531 inst->alg.base.cra_blocksize = 1;
532 inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
533 ctr->base.cra_alignmask;
534 inst->alg.ivsize = 16;
535 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
536 inst->alg.maxauthsize = 16;
537 inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
538 inst->alg.init = crypto_ccm_init_tfm;
539 inst->alg.exit = crypto_ccm_exit_tfm;
540 inst->alg.setkey = crypto_ccm_setkey;
541 inst->alg.setauthsize = crypto_ccm_setauthsize;
542 inst->alg.encrypt = crypto_ccm_encrypt;
543 inst->alg.decrypt = crypto_ccm_decrypt;
544
545 inst->free = crypto_ccm_free;
546
547 err = aead_register_instance(tmpl, inst);
548 if (err)
549 goto err_drop_ctr;
550
551out_put_mac:
552 crypto_mod_put(mac_alg);
553 return err;
554
555err_drop_ctr:
556 crypto_drop_skcipher(&ictx->ctr);
557err_drop_mac:
558 crypto_drop_ahash(&ictx->mac);
559err_free_inst:
560 kfree(inst);
561 goto out_put_mac;
562}
563
564static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
565{
566 const char *cipher_name;
567 char ctr_name[CRYPTO_MAX_ALG_NAME];
568 char mac_name[CRYPTO_MAX_ALG_NAME];
569
570 cipher_name = crypto_attr_alg_name(tb[1]);
571 if (IS_ERR(cipher_name))
572 return PTR_ERR(cipher_name);
573
574 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
575 cipher_name) >= CRYPTO_MAX_ALG_NAME)
576 return -ENAMETOOLONG;
577
578 if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
579 cipher_name) >= CRYPTO_MAX_ALG_NAME)
580 return -ENAMETOOLONG;
581
582 return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
583}
584
585static int crypto_ccm_base_create(struct crypto_template *tmpl,
586 struct rtattr **tb)
587{
588 const char *ctr_name;
589 const char *mac_name;
590
591 ctr_name = crypto_attr_alg_name(tb[1]);
592 if (IS_ERR(ctr_name))
593 return PTR_ERR(ctr_name);
594
595 mac_name = crypto_attr_alg_name(tb[2]);
596 if (IS_ERR(mac_name))
597 return PTR_ERR(mac_name);
598
599 return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
600}
601
602static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
603 unsigned int keylen)
604{
605 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
606 struct crypto_aead *child = ctx->child;
607 int err;
608
609 if (keylen < 3)
610 return -EINVAL;
611
612 keylen -= 3;
613 memcpy(ctx->nonce, key + keylen, 3);
614
615 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
616 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
617 CRYPTO_TFM_REQ_MASK);
618 err = crypto_aead_setkey(child, key, keylen);
619 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
620 CRYPTO_TFM_RES_MASK);
621
622 return err;
623}
624
625static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
626 unsigned int authsize)
627{
628 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
629
630 switch (authsize) {
631 case 8:
632 case 12:
633 case 16:
634 break;
635 default:
636 return -EINVAL;
637 }
638
639 return crypto_aead_setauthsize(ctx->child, authsize);
640}
641
642static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
643{
644 struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
645 struct aead_request *subreq = &rctx->subreq;
646 struct crypto_aead *aead = crypto_aead_reqtfm(req);
647 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
648 struct crypto_aead *child = ctx->child;
649 struct scatterlist *sg;
650 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
651 crypto_aead_alignmask(child) + 1);
652
653 /* L' */
654 iv[0] = 3;
655
656 memcpy(iv + 1, ctx->nonce, 3);
657 memcpy(iv + 4, req->iv, 8);
658
659 scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
660
661 sg_init_table(rctx->src, 3);
662 sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
663 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
664 if (sg != rctx->src + 1)
665 sg_chain(rctx->src, 2, sg);
666
667 if (req->src != req->dst) {
668 sg_init_table(rctx->dst, 3);
669 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
670 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
671 if (sg != rctx->dst + 1)
672 sg_chain(rctx->dst, 2, sg);
673 }
674
675 aead_request_set_tfm(subreq, child);
676 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
677 req->base.data);
678 aead_request_set_crypt(subreq, rctx->src,
679 req->src == req->dst ? rctx->src : rctx->dst,
680 req->cryptlen, iv);
681 aead_request_set_ad(subreq, req->assoclen - 8);
682
683 return subreq;
684}
685
686static int crypto_rfc4309_encrypt(struct aead_request *req)
687{
688 if (req->assoclen != 16 && req->assoclen != 20)
689 return -EINVAL;
690
691 req = crypto_rfc4309_crypt(req);
692
693 return crypto_aead_encrypt(req);
694}
695
696static int crypto_rfc4309_decrypt(struct aead_request *req)
697{
698 if (req->assoclen != 16 && req->assoclen != 20)
699 return -EINVAL;
700
701 req = crypto_rfc4309_crypt(req);
702
703 return crypto_aead_decrypt(req);
704}
705
706static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
707{
708 struct aead_instance *inst = aead_alg_instance(tfm);
709 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
710 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
711 struct crypto_aead *aead;
712 unsigned long align;
713
714 aead = crypto_spawn_aead(spawn);
715 if (IS_ERR(aead))
716 return PTR_ERR(aead);
717
718 ctx->child = aead;
719
720 align = crypto_aead_alignmask(aead);
721 align &= ~(crypto_tfm_ctx_alignment() - 1);
722 crypto_aead_set_reqsize(
723 tfm,
724 sizeof(struct crypto_rfc4309_req_ctx) +
725 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
726 align + 32);
727
728 return 0;
729}
730
731static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
732{
733 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
734
735 crypto_free_aead(ctx->child);
736}
737
738static void crypto_rfc4309_free(struct aead_instance *inst)
739{
740 crypto_drop_aead(aead_instance_ctx(inst));
741 kfree(inst);
742}
743
744static int crypto_rfc4309_create(struct crypto_template *tmpl,
745 struct rtattr **tb)
746{
747 struct crypto_attr_type *algt;
748 struct aead_instance *inst;
749 struct crypto_aead_spawn *spawn;
750 struct aead_alg *alg;
751 const char *ccm_name;
752 int err;
753
754 algt = crypto_get_attr_type(tb);
755 if (IS_ERR(algt))
756 return PTR_ERR(algt);
757
758 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
759 return -EINVAL;
760
761 ccm_name = crypto_attr_alg_name(tb[1]);
762 if (IS_ERR(ccm_name))
763 return PTR_ERR(ccm_name);
764
765 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
766 if (!inst)
767 return -ENOMEM;
768
769 spawn = aead_instance_ctx(inst);
770 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
771 err = crypto_grab_aead(spawn, ccm_name, 0,
772 crypto_requires_sync(algt->type, algt->mask));
773 if (err)
774 goto out_free_inst;
775
776 alg = crypto_spawn_aead_alg(spawn);
777
778 err = -EINVAL;
779
780 /* We only support 16-byte blocks. */
781 if (crypto_aead_alg_ivsize(alg) != 16)
782 goto out_drop_alg;
783
784 /* Not a stream cipher? */
785 if (alg->base.cra_blocksize != 1)
786 goto out_drop_alg;
787
788 err = -ENAMETOOLONG;
789 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
790 "rfc4309(%s)", alg->base.cra_name) >=
791 CRYPTO_MAX_ALG_NAME ||
792 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
793 "rfc4309(%s)", alg->base.cra_driver_name) >=
794 CRYPTO_MAX_ALG_NAME)
795 goto out_drop_alg;
796
797 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
798 inst->alg.base.cra_priority = alg->base.cra_priority;
799 inst->alg.base.cra_blocksize = 1;
800 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
801
802 inst->alg.ivsize = 8;
803 inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
804 inst->alg.maxauthsize = 16;
805
806 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
807
808 inst->alg.init = crypto_rfc4309_init_tfm;
809 inst->alg.exit = crypto_rfc4309_exit_tfm;
810
811 inst->alg.setkey = crypto_rfc4309_setkey;
812 inst->alg.setauthsize = crypto_rfc4309_setauthsize;
813 inst->alg.encrypt = crypto_rfc4309_encrypt;
814 inst->alg.decrypt = crypto_rfc4309_decrypt;
815
816 inst->free = crypto_rfc4309_free;
817
818 err = aead_register_instance(tmpl, inst);
819 if (err)
820 goto out_drop_alg;
821
822out:
823 return err;
824
825out_drop_alg:
826 crypto_drop_aead(spawn);
827out_free_inst:
828 kfree(inst);
829 goto out;
830}
831
832static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
833 const u8 *inkey, unsigned int keylen)
834{
835 struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
836
837 return crypto_cipher_setkey(ctx->child, inkey, keylen);
838}
839
840static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
841{
842 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
843 int bs = crypto_shash_digestsize(pdesc->tfm);
844 u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
845
846 ctx->len = 0;
847 memset(dg, 0, bs);
848
849 return 0;
850}
851
852static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
853 unsigned int len)
854{
855 struct crypto_shash *parent = pdesc->tfm;
856 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
857 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
858 struct crypto_cipher *tfm = tctx->child;
859 int bs = crypto_shash_digestsize(parent);
860 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
861
862 while (len > 0) {
863 unsigned int l = min(len, bs - ctx->len);
864
865 crypto_xor(dg + ctx->len, p, l);
866 ctx->len +=l;
867 len -= l;
868 p += l;
869
870 if (ctx->len == bs) {
871 crypto_cipher_encrypt_one(tfm, dg, dg);
872 ctx->len = 0;
873 }
874 }
875
876 return 0;
877}
878
879static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
880{
881 struct crypto_shash *parent = pdesc->tfm;
882 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
883 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
884 struct crypto_cipher *tfm = tctx->child;
885 int bs = crypto_shash_digestsize(parent);
886 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
887
888 if (ctx->len)
889 crypto_cipher_encrypt_one(tfm, dg, dg);
890
891 memcpy(out, dg, bs);
892 return 0;
893}
894
895static int cbcmac_init_tfm(struct crypto_tfm *tfm)
896{
897 struct crypto_cipher *cipher;
898 struct crypto_instance *inst = (void *)tfm->__crt_alg;
899 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
900 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
901
902 cipher = crypto_spawn_cipher(spawn);
903 if (IS_ERR(cipher))
904 return PTR_ERR(cipher);
905
906 ctx->child = cipher;
907
908 return 0;
909};
910
911static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
912{
913 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
914 crypto_free_cipher(ctx->child);
915}
916
917static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
918{
919 struct shash_instance *inst;
920 struct crypto_alg *alg;
921 int err;
922
923 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
924 if (err)
925 return err;
926
927 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
928 CRYPTO_ALG_TYPE_MASK);
929 if (IS_ERR(alg))
930 return PTR_ERR(alg);
931
932 inst = shash_alloc_instance("cbcmac", alg);
933 err = PTR_ERR(inst);
934 if (IS_ERR(inst))
935 goto out_put_alg;
936
937 err = crypto_init_spawn(shash_instance_ctx(inst), alg,
938 shash_crypto_instance(inst),
939 CRYPTO_ALG_TYPE_MASK);
940 if (err)
941 goto out_free_inst;
942
943 inst->alg.base.cra_priority = alg->cra_priority;
944 inst->alg.base.cra_blocksize = 1;
945
946 inst->alg.digestsize = alg->cra_blocksize;
947 inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
948 alg->cra_alignmask + 1) +
949 alg->cra_blocksize;
950
951 inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
952 inst->alg.base.cra_init = cbcmac_init_tfm;
953 inst->alg.base.cra_exit = cbcmac_exit_tfm;
954
955 inst->alg.init = crypto_cbcmac_digest_init;
956 inst->alg.update = crypto_cbcmac_digest_update;
957 inst->alg.final = crypto_cbcmac_digest_final;
958 inst->alg.setkey = crypto_cbcmac_digest_setkey;
959
960 err = shash_register_instance(tmpl, inst);
961
962out_free_inst:
963 if (err)
964 shash_free_instance(shash_crypto_instance(inst));
965
966out_put_alg:
967 crypto_mod_put(alg);
968 return err;
969}
970
971static struct crypto_template crypto_ccm_tmpls[] = {
972 {
973 .name = "cbcmac",
974 .create = cbcmac_create,
975 .free = shash_free_instance,
976 .module = THIS_MODULE,
977 }, {
978 .name = "ccm_base",
979 .create = crypto_ccm_base_create,
980 .module = THIS_MODULE,
981 }, {
982 .name = "ccm",
983 .create = crypto_ccm_create,
984 .module = THIS_MODULE,
985 }, {
986 .name = "rfc4309",
987 .create = crypto_rfc4309_create,
988 .module = THIS_MODULE,
989 },
990};
991
992static int __init crypto_ccm_module_init(void)
993{
994 return crypto_register_templates(crypto_ccm_tmpls,
995 ARRAY_SIZE(crypto_ccm_tmpls));
996}
997
998static void __exit crypto_ccm_module_exit(void)
999{
1000 crypto_unregister_templates(crypto_ccm_tmpls,
1001 ARRAY_SIZE(crypto_ccm_tmpls));
1002}
1003
1004subsys_initcall(crypto_ccm_module_init);
1005module_exit(crypto_ccm_module_exit);
1006
1007MODULE_LICENSE("GPL");
1008MODULE_DESCRIPTION("Counter with CBC MAC");
1009MODULE_ALIAS_CRYPTO("ccm_base");
1010MODULE_ALIAS_CRYPTO("rfc4309");
1011MODULE_ALIAS_CRYPTO("ccm");
1012MODULE_ALIAS_CRYPTO("cbcmac");
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, 0);
220
221 compute_mac(tfm, data_src, n, pctx);
222 len -= n;
223
224 scatterwalk_unmap(data_src, 0);
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 get_data_to_compute(cipher, pctx, plain, cryptlen);
275
276out:
277 return err;
278}
279
280static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
281{
282 struct aead_request *req = areq->data;
283 struct crypto_aead *aead = crypto_aead_reqtfm(req);
284 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
285 u8 *odata = pctx->odata;
286
287 if (!err)
288 scatterwalk_map_and_copy(odata, req->dst, req->cryptlen,
289 crypto_aead_authsize(aead), 1);
290 aead_request_complete(req, err);
291}
292
293static inline int crypto_ccm_check_iv(const u8 *iv)
294{
295 /* 2 <= L <= 8, so 1 <= L' <= 7. */
296 if (1 > iv[0] || iv[0] > 7)
297 return -EINVAL;
298
299 return 0;
300}
301
302static int crypto_ccm_encrypt(struct aead_request *req)
303{
304 struct crypto_aead *aead = crypto_aead_reqtfm(req);
305 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
306 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
307 struct ablkcipher_request *abreq = &pctx->abreq;
308 struct scatterlist *dst;
309 unsigned int cryptlen = req->cryptlen;
310 u8 *odata = pctx->odata;
311 u8 *iv = req->iv;
312 int err;
313
314 err = crypto_ccm_check_iv(iv);
315 if (err)
316 return err;
317
318 pctx->flags = aead_request_flags(req);
319
320 err = crypto_ccm_auth(req, req->src, cryptlen);
321 if (err)
322 return err;
323
324 /* Note: rfc 3610 and NIST 800-38C require counter of
325 * zero to encrypt auth tag.
326 */
327 memset(iv + 15 - iv[0], 0, iv[0] + 1);
328
329 sg_init_table(pctx->src, 2);
330 sg_set_buf(pctx->src, odata, 16);
331 scatterwalk_sg_chain(pctx->src, 2, req->src);
332
333 dst = pctx->src;
334 if (req->src != req->dst) {
335 sg_init_table(pctx->dst, 2);
336 sg_set_buf(pctx->dst, odata, 16);
337 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
338 dst = pctx->dst;
339 }
340
341 ablkcipher_request_set_tfm(abreq, ctx->ctr);
342 ablkcipher_request_set_callback(abreq, pctx->flags,
343 crypto_ccm_encrypt_done, req);
344 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
345 err = crypto_ablkcipher_encrypt(abreq);
346 if (err)
347 return err;
348
349 /* copy authtag to end of dst */
350 scatterwalk_map_and_copy(odata, req->dst, cryptlen,
351 crypto_aead_authsize(aead), 1);
352 return err;
353}
354
355static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
356 int err)
357{
358 struct aead_request *req = areq->data;
359 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
360 struct crypto_aead *aead = crypto_aead_reqtfm(req);
361 unsigned int authsize = crypto_aead_authsize(aead);
362 unsigned int cryptlen = req->cryptlen - authsize;
363
364 if (!err) {
365 err = crypto_ccm_auth(req, req->dst, cryptlen);
366 if (!err && memcmp(pctx->auth_tag, pctx->odata, authsize))
367 err = -EBADMSG;
368 }
369 aead_request_complete(req, err);
370}
371
372static int crypto_ccm_decrypt(struct aead_request *req)
373{
374 struct crypto_aead *aead = crypto_aead_reqtfm(req);
375 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
376 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
377 struct ablkcipher_request *abreq = &pctx->abreq;
378 struct scatterlist *dst;
379 unsigned int authsize = crypto_aead_authsize(aead);
380 unsigned int cryptlen = req->cryptlen;
381 u8 *authtag = pctx->auth_tag;
382 u8 *odata = pctx->odata;
383 u8 *iv = req->iv;
384 int err;
385
386 if (cryptlen < authsize)
387 return -EINVAL;
388 cryptlen -= authsize;
389
390 err = crypto_ccm_check_iv(iv);
391 if (err)
392 return err;
393
394 pctx->flags = aead_request_flags(req);
395
396 scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0);
397
398 memset(iv + 15 - iv[0], 0, iv[0] + 1);
399
400 sg_init_table(pctx->src, 2);
401 sg_set_buf(pctx->src, authtag, 16);
402 scatterwalk_sg_chain(pctx->src, 2, req->src);
403
404 dst = pctx->src;
405 if (req->src != req->dst) {
406 sg_init_table(pctx->dst, 2);
407 sg_set_buf(pctx->dst, authtag, 16);
408 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
409 dst = pctx->dst;
410 }
411
412 ablkcipher_request_set_tfm(abreq, ctx->ctr);
413 ablkcipher_request_set_callback(abreq, pctx->flags,
414 crypto_ccm_decrypt_done, req);
415 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
416 err = crypto_ablkcipher_decrypt(abreq);
417 if (err)
418 return err;
419
420 err = crypto_ccm_auth(req, req->dst, cryptlen);
421 if (err)
422 return err;
423
424 /* verify */
425 if (memcmp(authtag, odata, authsize))
426 return -EBADMSG;
427
428 return err;
429}
430
431static int crypto_ccm_init_tfm(struct crypto_tfm *tfm)
432{
433 struct crypto_instance *inst = (void *)tfm->__crt_alg;
434 struct ccm_instance_ctx *ictx = crypto_instance_ctx(inst);
435 struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
436 struct crypto_cipher *cipher;
437 struct crypto_ablkcipher *ctr;
438 unsigned long align;
439 int err;
440
441 cipher = crypto_spawn_cipher(&ictx->cipher);
442 if (IS_ERR(cipher))
443 return PTR_ERR(cipher);
444
445 ctr = crypto_spawn_skcipher(&ictx->ctr);
446 err = PTR_ERR(ctr);
447 if (IS_ERR(ctr))
448 goto err_free_cipher;
449
450 ctx->cipher = cipher;
451 ctx->ctr = ctr;
452
453 align = crypto_tfm_alg_alignmask(tfm);
454 align &= ~(crypto_tfm_ctx_alignment() - 1);
455 tfm->crt_aead.reqsize = align +
456 sizeof(struct crypto_ccm_req_priv_ctx) +
457 crypto_ablkcipher_reqsize(ctr);
458
459 return 0;
460
461err_free_cipher:
462 crypto_free_cipher(cipher);
463 return err;
464}
465
466static void crypto_ccm_exit_tfm(struct crypto_tfm *tfm)
467{
468 struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
469
470 crypto_free_cipher(ctx->cipher);
471 crypto_free_ablkcipher(ctx->ctr);
472}
473
474static struct crypto_instance *crypto_ccm_alloc_common(struct rtattr **tb,
475 const char *full_name,
476 const char *ctr_name,
477 const char *cipher_name)
478{
479 struct crypto_attr_type *algt;
480 struct crypto_instance *inst;
481 struct crypto_alg *ctr;
482 struct crypto_alg *cipher;
483 struct ccm_instance_ctx *ictx;
484 int err;
485
486 algt = crypto_get_attr_type(tb);
487 err = PTR_ERR(algt);
488 if (IS_ERR(algt))
489 return ERR_PTR(err);
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 err = PTR_ERR(cipher);
497 if (IS_ERR(cipher))
498 return ERR_PTR(err);
499
500 err = -EINVAL;
501 if (cipher->cra_blocksize != 16)
502 goto out_put_cipher;
503
504 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
505 err = -ENOMEM;
506 if (!inst)
507 goto out_put_cipher;
508
509 ictx = crypto_instance_ctx(inst);
510
511 err = crypto_init_spawn(&ictx->cipher, cipher, inst,
512 CRYPTO_ALG_TYPE_MASK);
513 if (err)
514 goto err_free_inst;
515
516 crypto_set_skcipher_spawn(&ictx->ctr, inst);
517 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
518 crypto_requires_sync(algt->type,
519 algt->mask));
520 if (err)
521 goto err_drop_cipher;
522
523 ctr = crypto_skcipher_spawn_alg(&ictx->ctr);
524
525 /* Not a stream cipher? */
526 err = -EINVAL;
527 if (ctr->cra_blocksize != 1)
528 goto err_drop_ctr;
529
530 /* We want the real thing! */
531 if (ctr->cra_ablkcipher.ivsize != 16)
532 goto err_drop_ctr;
533
534 err = -ENAMETOOLONG;
535 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
536 "ccm_base(%s,%s)", ctr->cra_driver_name,
537 cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
538 goto err_drop_ctr;
539
540 memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
541
542 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
543 inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
544 inst->alg.cra_priority = cipher->cra_priority + ctr->cra_priority;
545 inst->alg.cra_blocksize = 1;
546 inst->alg.cra_alignmask = cipher->cra_alignmask | ctr->cra_alignmask |
547 (__alignof__(u32) - 1);
548 inst->alg.cra_type = &crypto_aead_type;
549 inst->alg.cra_aead.ivsize = 16;
550 inst->alg.cra_aead.maxauthsize = 16;
551 inst->alg.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
552 inst->alg.cra_init = crypto_ccm_init_tfm;
553 inst->alg.cra_exit = crypto_ccm_exit_tfm;
554 inst->alg.cra_aead.setkey = crypto_ccm_setkey;
555 inst->alg.cra_aead.setauthsize = crypto_ccm_setauthsize;
556 inst->alg.cra_aead.encrypt = crypto_ccm_encrypt;
557 inst->alg.cra_aead.decrypt = crypto_ccm_decrypt;
558
559out:
560 crypto_mod_put(cipher);
561 return inst;
562
563err_drop_ctr:
564 crypto_drop_skcipher(&ictx->ctr);
565err_drop_cipher:
566 crypto_drop_spawn(&ictx->cipher);
567err_free_inst:
568 kfree(inst);
569out_put_cipher:
570 inst = ERR_PTR(err);
571 goto out;
572}
573
574static struct crypto_instance *crypto_ccm_alloc(struct rtattr **tb)
575{
576 int err;
577 const char *cipher_name;
578 char ctr_name[CRYPTO_MAX_ALG_NAME];
579 char full_name[CRYPTO_MAX_ALG_NAME];
580
581 cipher_name = crypto_attr_alg_name(tb[1]);
582 err = PTR_ERR(cipher_name);
583 if (IS_ERR(cipher_name))
584 return ERR_PTR(err);
585
586 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
587 cipher_name) >= CRYPTO_MAX_ALG_NAME)
588 return ERR_PTR(-ENAMETOOLONG);
589
590 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
591 CRYPTO_MAX_ALG_NAME)
592 return ERR_PTR(-ENAMETOOLONG);
593
594 return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
595}
596
597static void crypto_ccm_free(struct crypto_instance *inst)
598{
599 struct ccm_instance_ctx *ctx = crypto_instance_ctx(inst);
600
601 crypto_drop_spawn(&ctx->cipher);
602 crypto_drop_skcipher(&ctx->ctr);
603 kfree(inst);
604}
605
606static struct crypto_template crypto_ccm_tmpl = {
607 .name = "ccm",
608 .alloc = crypto_ccm_alloc,
609 .free = crypto_ccm_free,
610 .module = THIS_MODULE,
611};
612
613static struct crypto_instance *crypto_ccm_base_alloc(struct rtattr **tb)
614{
615 int err;
616 const char *ctr_name;
617 const char *cipher_name;
618 char full_name[CRYPTO_MAX_ALG_NAME];
619
620 ctr_name = crypto_attr_alg_name(tb[1]);
621 err = PTR_ERR(ctr_name);
622 if (IS_ERR(ctr_name))
623 return ERR_PTR(err);
624
625 cipher_name = crypto_attr_alg_name(tb[2]);
626 err = PTR_ERR(cipher_name);
627 if (IS_ERR(cipher_name))
628 return ERR_PTR(err);
629
630 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
631 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
632 return ERR_PTR(-ENAMETOOLONG);
633
634 return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
635}
636
637static struct crypto_template crypto_ccm_base_tmpl = {
638 .name = "ccm_base",
639 .alloc = crypto_ccm_base_alloc,
640 .free = crypto_ccm_free,
641 .module = THIS_MODULE,
642};
643
644static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
645 unsigned int keylen)
646{
647 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
648 struct crypto_aead *child = ctx->child;
649 int err;
650
651 if (keylen < 3)
652 return -EINVAL;
653
654 keylen -= 3;
655 memcpy(ctx->nonce, key + keylen, 3);
656
657 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
658 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
659 CRYPTO_TFM_REQ_MASK);
660 err = crypto_aead_setkey(child, key, keylen);
661 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
662 CRYPTO_TFM_RES_MASK);
663
664 return err;
665}
666
667static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
668 unsigned int authsize)
669{
670 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
671
672 switch (authsize) {
673 case 8:
674 case 12:
675 case 16:
676 break;
677 default:
678 return -EINVAL;
679 }
680
681 return crypto_aead_setauthsize(ctx->child, authsize);
682}
683
684static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
685{
686 struct aead_request *subreq = aead_request_ctx(req);
687 struct crypto_aead *aead = crypto_aead_reqtfm(req);
688 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
689 struct crypto_aead *child = ctx->child;
690 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
691 crypto_aead_alignmask(child) + 1);
692
693 /* L' */
694 iv[0] = 3;
695
696 memcpy(iv + 1, ctx->nonce, 3);
697 memcpy(iv + 4, req->iv, 8);
698
699 aead_request_set_tfm(subreq, child);
700 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
701 req->base.data);
702 aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
703 aead_request_set_assoc(subreq, req->assoc, req->assoclen);
704
705 return subreq;
706}
707
708static int crypto_rfc4309_encrypt(struct aead_request *req)
709{
710 req = crypto_rfc4309_crypt(req);
711
712 return crypto_aead_encrypt(req);
713}
714
715static int crypto_rfc4309_decrypt(struct aead_request *req)
716{
717 req = crypto_rfc4309_crypt(req);
718
719 return crypto_aead_decrypt(req);
720}
721
722static int crypto_rfc4309_init_tfm(struct crypto_tfm *tfm)
723{
724 struct crypto_instance *inst = (void *)tfm->__crt_alg;
725 struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
726 struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
727 struct crypto_aead *aead;
728 unsigned long align;
729
730 aead = crypto_spawn_aead(spawn);
731 if (IS_ERR(aead))
732 return PTR_ERR(aead);
733
734 ctx->child = aead;
735
736 align = crypto_aead_alignmask(aead);
737 align &= ~(crypto_tfm_ctx_alignment() - 1);
738 tfm->crt_aead.reqsize = sizeof(struct aead_request) +
739 ALIGN(crypto_aead_reqsize(aead),
740 crypto_tfm_ctx_alignment()) +
741 align + 16;
742
743 return 0;
744}
745
746static void crypto_rfc4309_exit_tfm(struct crypto_tfm *tfm)
747{
748 struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
749
750 crypto_free_aead(ctx->child);
751}
752
753static struct crypto_instance *crypto_rfc4309_alloc(struct rtattr **tb)
754{
755 struct crypto_attr_type *algt;
756 struct crypto_instance *inst;
757 struct crypto_aead_spawn *spawn;
758 struct crypto_alg *alg;
759 const char *ccm_name;
760 int err;
761
762 algt = crypto_get_attr_type(tb);
763 err = PTR_ERR(algt);
764 if (IS_ERR(algt))
765 return ERR_PTR(err);
766
767 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
768 return ERR_PTR(-EINVAL);
769
770 ccm_name = crypto_attr_alg_name(tb[1]);
771 err = PTR_ERR(ccm_name);
772 if (IS_ERR(ccm_name))
773 return ERR_PTR(err);
774
775 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
776 if (!inst)
777 return ERR_PTR(-ENOMEM);
778
779 spawn = crypto_instance_ctx(inst);
780 crypto_set_aead_spawn(spawn, inst);
781 err = crypto_grab_aead(spawn, ccm_name, 0,
782 crypto_requires_sync(algt->type, algt->mask));
783 if (err)
784 goto out_free_inst;
785
786 alg = crypto_aead_spawn_alg(spawn);
787
788 err = -EINVAL;
789
790 /* We only support 16-byte blocks. */
791 if (alg->cra_aead.ivsize != 16)
792 goto out_drop_alg;
793
794 /* Not a stream cipher? */
795 if (alg->cra_blocksize != 1)
796 goto out_drop_alg;
797
798 err = -ENAMETOOLONG;
799 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
800 "rfc4309(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
801 snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
802 "rfc4309(%s)", alg->cra_driver_name) >=
803 CRYPTO_MAX_ALG_NAME)
804 goto out_drop_alg;
805
806 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
807 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
808 inst->alg.cra_priority = alg->cra_priority;
809 inst->alg.cra_blocksize = 1;
810 inst->alg.cra_alignmask = alg->cra_alignmask;
811 inst->alg.cra_type = &crypto_nivaead_type;
812
813 inst->alg.cra_aead.ivsize = 8;
814 inst->alg.cra_aead.maxauthsize = 16;
815
816 inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
817
818 inst->alg.cra_init = crypto_rfc4309_init_tfm;
819 inst->alg.cra_exit = crypto_rfc4309_exit_tfm;
820
821 inst->alg.cra_aead.setkey = crypto_rfc4309_setkey;
822 inst->alg.cra_aead.setauthsize = crypto_rfc4309_setauthsize;
823 inst->alg.cra_aead.encrypt = crypto_rfc4309_encrypt;
824 inst->alg.cra_aead.decrypt = crypto_rfc4309_decrypt;
825
826 inst->alg.cra_aead.geniv = "seqiv";
827
828out:
829 return inst;
830
831out_drop_alg:
832 crypto_drop_aead(spawn);
833out_free_inst:
834 kfree(inst);
835 inst = ERR_PTR(err);
836 goto out;
837}
838
839static void crypto_rfc4309_free(struct crypto_instance *inst)
840{
841 crypto_drop_spawn(crypto_instance_ctx(inst));
842 kfree(inst);
843}
844
845static struct crypto_template crypto_rfc4309_tmpl = {
846 .name = "rfc4309",
847 .alloc = crypto_rfc4309_alloc,
848 .free = crypto_rfc4309_free,
849 .module = THIS_MODULE,
850};
851
852static int __init crypto_ccm_module_init(void)
853{
854 int err;
855
856 err = crypto_register_template(&crypto_ccm_base_tmpl);
857 if (err)
858 goto out;
859
860 err = crypto_register_template(&crypto_ccm_tmpl);
861 if (err)
862 goto out_undo_base;
863
864 err = crypto_register_template(&crypto_rfc4309_tmpl);
865 if (err)
866 goto out_undo_ccm;
867
868out:
869 return err;
870
871out_undo_ccm:
872 crypto_unregister_template(&crypto_ccm_tmpl);
873out_undo_base:
874 crypto_unregister_template(&crypto_ccm_base_tmpl);
875 goto out;
876}
877
878static void __exit crypto_ccm_module_exit(void)
879{
880 crypto_unregister_template(&crypto_rfc4309_tmpl);
881 crypto_unregister_template(&crypto_ccm_tmpl);
882 crypto_unregister_template(&crypto_ccm_base_tmpl);
883}
884
885module_init(crypto_ccm_module_init);
886module_exit(crypto_ccm_module_exit);
887
888MODULE_LICENSE("GPL");
889MODULE_DESCRIPTION("Counter with CBC MAC");
890MODULE_ALIAS("ccm_base");
891MODULE_ALIAS("rfc4309");