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