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
24 struct ccm_instance_ctx {
25 struct crypto_skcipher_spawn ctr;
26 struct crypto_spawn cipher;
27 };
28
29 struct crypto_ccm_ctx {
30 struct crypto_cipher *cipher;
31 struct crypto_skcipher *ctr;
32 };
33
34 struct crypto_rfc4309_ctx {
35 struct crypto_aead *child;
36 u8 nonce[3];
37 };
38
39 struct crypto_rfc4309_req_ctx {
40 struct scatterlist src[3];
41 struct scatterlist dst[3];
42 struct aead_request subreq;
43 };
44
45 struct 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
crypto_ccm_reqctx(struct aead_request * req)56 static 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
set_msg_len(u8 * block,unsigned int msglen,int csize)64 static 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
crypto_ccm_setkey(struct crypto_aead * aead,const u8 * key,unsigned int keylen)82 static 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
106 out:
107 return err;
108 }
109
crypto_ccm_setauthsize(struct crypto_aead * tfm,unsigned int authsize)110 static 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
format_input(u8 * info,struct aead_request * req,unsigned int cryptlen)129 static 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
format_adata(u8 * adata,unsigned int a)151 static 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
compute_mac(struct crypto_cipher * tfm,u8 * data,int n,struct crypto_ccm_req_priv_ctx * pctx)170 static 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
get_data_to_compute(struct crypto_cipher * tfm,struct crypto_ccm_req_priv_ctx * pctx,struct scatterlist * sg,unsigned int len)209 static 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
crypto_ccm_auth(struct aead_request * req,struct scatterlist * plain,unsigned int cryptlen)251 static 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
283 out:
284 return err;
285 }
286
crypto_ccm_encrypt_done(struct crypto_async_request * areq,int err)287 static 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
crypto_ccm_check_iv(const u8 * iv)301 static 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
crypto_ccm_init_crypt(struct aead_request * req,u8 * tag)310 static 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
crypto_ccm_encrypt(struct aead_request * req)345 static 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
crypto_ccm_decrypt_done(struct crypto_async_request * areq,int err)383 static 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
crypto_ccm_decrypt(struct aead_request * req)405 static 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 = pctx->idata;
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 memcpy(iv, req->iv, 16);
433
434 skcipher_request_set_tfm(skreq, ctx->ctr);
435 skcipher_request_set_callback(skreq, pctx->flags,
436 crypto_ccm_decrypt_done, req);
437 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
438 err = crypto_skcipher_decrypt(skreq);
439 if (err)
440 return err;
441
442 err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
443 if (err)
444 return err;
445
446 /* verify */
447 if (crypto_memneq(authtag, odata, authsize))
448 return -EBADMSG;
449
450 return err;
451 }
452
crypto_ccm_init_tfm(struct crypto_aead * tfm)453 static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
454 {
455 struct aead_instance *inst = aead_alg_instance(tfm);
456 struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
457 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
458 struct crypto_cipher *cipher;
459 struct crypto_skcipher *ctr;
460 unsigned long align;
461 int err;
462
463 cipher = crypto_spawn_cipher(&ictx->cipher);
464 if (IS_ERR(cipher))
465 return PTR_ERR(cipher);
466
467 ctr = crypto_spawn_skcipher2(&ictx->ctr);
468 err = PTR_ERR(ctr);
469 if (IS_ERR(ctr))
470 goto err_free_cipher;
471
472 ctx->cipher = cipher;
473 ctx->ctr = ctr;
474
475 align = crypto_aead_alignmask(tfm);
476 align &= ~(crypto_tfm_ctx_alignment() - 1);
477 crypto_aead_set_reqsize(
478 tfm,
479 align + sizeof(struct crypto_ccm_req_priv_ctx) +
480 crypto_skcipher_reqsize(ctr));
481
482 return 0;
483
484 err_free_cipher:
485 crypto_free_cipher(cipher);
486 return err;
487 }
488
crypto_ccm_exit_tfm(struct crypto_aead * tfm)489 static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
490 {
491 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
492
493 crypto_free_cipher(ctx->cipher);
494 crypto_free_skcipher(ctx->ctr);
495 }
496
crypto_ccm_free(struct aead_instance * inst)497 static void crypto_ccm_free(struct aead_instance *inst)
498 {
499 struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
500
501 crypto_drop_spawn(&ctx->cipher);
502 crypto_drop_skcipher(&ctx->ctr);
503 kfree(inst);
504 }
505
crypto_ccm_create_common(struct crypto_template * tmpl,struct rtattr ** tb,const char * full_name,const char * ctr_name,const char * cipher_name)506 static int crypto_ccm_create_common(struct crypto_template *tmpl,
507 struct rtattr **tb,
508 const char *full_name,
509 const char *ctr_name,
510 const char *cipher_name)
511 {
512 struct crypto_attr_type *algt;
513 struct aead_instance *inst;
514 struct skcipher_alg *ctr;
515 struct crypto_alg *cipher;
516 struct ccm_instance_ctx *ictx;
517 int err;
518
519 algt = crypto_get_attr_type(tb);
520 if (IS_ERR(algt))
521 return PTR_ERR(algt);
522
523 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
524 return -EINVAL;
525
526 cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER,
527 CRYPTO_ALG_TYPE_MASK);
528 if (IS_ERR(cipher))
529 return PTR_ERR(cipher);
530
531 err = -EINVAL;
532 if (cipher->cra_blocksize != 16)
533 goto out_put_cipher;
534
535 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
536 err = -ENOMEM;
537 if (!inst)
538 goto out_put_cipher;
539
540 ictx = aead_instance_ctx(inst);
541
542 err = crypto_init_spawn(&ictx->cipher, cipher,
543 aead_crypto_instance(inst),
544 CRYPTO_ALG_TYPE_MASK);
545 if (err)
546 goto err_free_inst;
547
548 crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
549 err = crypto_grab_skcipher2(&ictx->ctr, ctr_name, 0,
550 crypto_requires_sync(algt->type,
551 algt->mask));
552 if (err)
553 goto err_drop_cipher;
554
555 ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
556
557 /* Not a stream cipher? */
558 err = -EINVAL;
559 if (ctr->base.cra_blocksize != 1)
560 goto err_drop_ctr;
561
562 /* We want the real thing! */
563 if (crypto_skcipher_alg_ivsize(ctr) != 16)
564 goto err_drop_ctr;
565
566 err = -ENAMETOOLONG;
567 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
568 "ccm_base(%s,%s)", ctr->base.cra_driver_name,
569 cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
570 goto err_drop_ctr;
571
572 memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
573
574 inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
575 inst->alg.base.cra_priority = (cipher->cra_priority +
576 ctr->base.cra_priority) / 2;
577 inst->alg.base.cra_blocksize = 1;
578 inst->alg.base.cra_alignmask = cipher->cra_alignmask |
579 ctr->base.cra_alignmask |
580 (__alignof__(u32) - 1);
581 inst->alg.ivsize = 16;
582 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
583 inst->alg.maxauthsize = 16;
584 inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
585 inst->alg.init = crypto_ccm_init_tfm;
586 inst->alg.exit = crypto_ccm_exit_tfm;
587 inst->alg.setkey = crypto_ccm_setkey;
588 inst->alg.setauthsize = crypto_ccm_setauthsize;
589 inst->alg.encrypt = crypto_ccm_encrypt;
590 inst->alg.decrypt = crypto_ccm_decrypt;
591
592 inst->free = crypto_ccm_free;
593
594 err = aead_register_instance(tmpl, inst);
595 if (err)
596 goto err_drop_ctr;
597
598 out_put_cipher:
599 crypto_mod_put(cipher);
600 return err;
601
602 err_drop_ctr:
603 crypto_drop_skcipher(&ictx->ctr);
604 err_drop_cipher:
605 crypto_drop_spawn(&ictx->cipher);
606 err_free_inst:
607 kfree(inst);
608 goto out_put_cipher;
609 }
610
crypto_ccm_create(struct crypto_template * tmpl,struct rtattr ** tb)611 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
612 {
613 const char *cipher_name;
614 char ctr_name[CRYPTO_MAX_ALG_NAME];
615 char full_name[CRYPTO_MAX_ALG_NAME];
616
617 cipher_name = crypto_attr_alg_name(tb[1]);
618 if (IS_ERR(cipher_name))
619 return PTR_ERR(cipher_name);
620
621 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
622 cipher_name) >= CRYPTO_MAX_ALG_NAME)
623 return -ENAMETOOLONG;
624
625 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
626 CRYPTO_MAX_ALG_NAME)
627 return -ENAMETOOLONG;
628
629 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
630 cipher_name);
631 }
632
633 static struct crypto_template crypto_ccm_tmpl = {
634 .name = "ccm",
635 .create = crypto_ccm_create,
636 .module = THIS_MODULE,
637 };
638
crypto_ccm_base_create(struct crypto_template * tmpl,struct rtattr ** tb)639 static int crypto_ccm_base_create(struct crypto_template *tmpl,
640 struct rtattr **tb)
641 {
642 const char *ctr_name;
643 const char *cipher_name;
644 char full_name[CRYPTO_MAX_ALG_NAME];
645
646 ctr_name = crypto_attr_alg_name(tb[1]);
647 if (IS_ERR(ctr_name))
648 return PTR_ERR(ctr_name);
649
650 cipher_name = crypto_attr_alg_name(tb[2]);
651 if (IS_ERR(cipher_name))
652 return PTR_ERR(cipher_name);
653
654 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
655 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
656 return -ENAMETOOLONG;
657
658 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
659 cipher_name);
660 }
661
662 static struct crypto_template crypto_ccm_base_tmpl = {
663 .name = "ccm_base",
664 .create = crypto_ccm_base_create,
665 .module = THIS_MODULE,
666 };
667
crypto_rfc4309_setkey(struct crypto_aead * parent,const u8 * key,unsigned int keylen)668 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
669 unsigned int keylen)
670 {
671 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
672 struct crypto_aead *child = ctx->child;
673 int err;
674
675 if (keylen < 3)
676 return -EINVAL;
677
678 keylen -= 3;
679 memcpy(ctx->nonce, key + keylen, 3);
680
681 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
682 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
683 CRYPTO_TFM_REQ_MASK);
684 err = crypto_aead_setkey(child, key, keylen);
685 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
686 CRYPTO_TFM_RES_MASK);
687
688 return err;
689 }
690
crypto_rfc4309_setauthsize(struct crypto_aead * parent,unsigned int authsize)691 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
692 unsigned int authsize)
693 {
694 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
695
696 switch (authsize) {
697 case 8:
698 case 12:
699 case 16:
700 break;
701 default:
702 return -EINVAL;
703 }
704
705 return crypto_aead_setauthsize(ctx->child, authsize);
706 }
707
crypto_rfc4309_crypt(struct aead_request * req)708 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
709 {
710 struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
711 struct aead_request *subreq = &rctx->subreq;
712 struct crypto_aead *aead = crypto_aead_reqtfm(req);
713 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
714 struct crypto_aead *child = ctx->child;
715 struct scatterlist *sg;
716 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
717 crypto_aead_alignmask(child) + 1);
718
719 /* L' */
720 iv[0] = 3;
721
722 memcpy(iv + 1, ctx->nonce, 3);
723 memcpy(iv + 4, req->iv, 8);
724
725 scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
726
727 sg_init_table(rctx->src, 3);
728 sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
729 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
730 if (sg != rctx->src + 1)
731 sg_chain(rctx->src, 2, sg);
732
733 if (req->src != req->dst) {
734 sg_init_table(rctx->dst, 3);
735 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
736 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
737 if (sg != rctx->dst + 1)
738 sg_chain(rctx->dst, 2, sg);
739 }
740
741 aead_request_set_tfm(subreq, child);
742 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
743 req->base.data);
744 aead_request_set_crypt(subreq, rctx->src,
745 req->src == req->dst ? rctx->src : rctx->dst,
746 req->cryptlen, iv);
747 aead_request_set_ad(subreq, req->assoclen - 8);
748
749 return subreq;
750 }
751
crypto_rfc4309_encrypt(struct aead_request * req)752 static int crypto_rfc4309_encrypt(struct aead_request *req)
753 {
754 if (req->assoclen != 16 && req->assoclen != 20)
755 return -EINVAL;
756
757 req = crypto_rfc4309_crypt(req);
758
759 return crypto_aead_encrypt(req);
760 }
761
crypto_rfc4309_decrypt(struct aead_request * req)762 static int crypto_rfc4309_decrypt(struct aead_request *req)
763 {
764 if (req->assoclen != 16 && req->assoclen != 20)
765 return -EINVAL;
766
767 req = crypto_rfc4309_crypt(req);
768
769 return crypto_aead_decrypt(req);
770 }
771
crypto_rfc4309_init_tfm(struct crypto_aead * tfm)772 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
773 {
774 struct aead_instance *inst = aead_alg_instance(tfm);
775 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
776 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
777 struct crypto_aead *aead;
778 unsigned long align;
779
780 aead = crypto_spawn_aead(spawn);
781 if (IS_ERR(aead))
782 return PTR_ERR(aead);
783
784 ctx->child = aead;
785
786 align = crypto_aead_alignmask(aead);
787 align &= ~(crypto_tfm_ctx_alignment() - 1);
788 crypto_aead_set_reqsize(
789 tfm,
790 sizeof(struct crypto_rfc4309_req_ctx) +
791 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
792 align + 32);
793
794 return 0;
795 }
796
crypto_rfc4309_exit_tfm(struct crypto_aead * tfm)797 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
798 {
799 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
800
801 crypto_free_aead(ctx->child);
802 }
803
crypto_rfc4309_free(struct aead_instance * inst)804 static void crypto_rfc4309_free(struct aead_instance *inst)
805 {
806 crypto_drop_aead(aead_instance_ctx(inst));
807 kfree(inst);
808 }
809
crypto_rfc4309_create(struct crypto_template * tmpl,struct rtattr ** tb)810 static int crypto_rfc4309_create(struct crypto_template *tmpl,
811 struct rtattr **tb)
812 {
813 struct crypto_attr_type *algt;
814 struct aead_instance *inst;
815 struct crypto_aead_spawn *spawn;
816 struct aead_alg *alg;
817 const char *ccm_name;
818 int err;
819
820 algt = crypto_get_attr_type(tb);
821 if (IS_ERR(algt))
822 return PTR_ERR(algt);
823
824 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
825 return -EINVAL;
826
827 ccm_name = crypto_attr_alg_name(tb[1]);
828 if (IS_ERR(ccm_name))
829 return PTR_ERR(ccm_name);
830
831 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
832 if (!inst)
833 return -ENOMEM;
834
835 spawn = aead_instance_ctx(inst);
836 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
837 err = crypto_grab_aead(spawn, ccm_name, 0,
838 crypto_requires_sync(algt->type, algt->mask));
839 if (err)
840 goto out_free_inst;
841
842 alg = crypto_spawn_aead_alg(spawn);
843
844 err = -EINVAL;
845
846 /* We only support 16-byte blocks. */
847 if (crypto_aead_alg_ivsize(alg) != 16)
848 goto out_drop_alg;
849
850 /* Not a stream cipher? */
851 if (alg->base.cra_blocksize != 1)
852 goto out_drop_alg;
853
854 err = -ENAMETOOLONG;
855 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
856 "rfc4309(%s)", alg->base.cra_name) >=
857 CRYPTO_MAX_ALG_NAME ||
858 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
859 "rfc4309(%s)", alg->base.cra_driver_name) >=
860 CRYPTO_MAX_ALG_NAME)
861 goto out_drop_alg;
862
863 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
864 inst->alg.base.cra_priority = alg->base.cra_priority;
865 inst->alg.base.cra_blocksize = 1;
866 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
867
868 inst->alg.ivsize = 8;
869 inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
870 inst->alg.maxauthsize = 16;
871
872 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
873
874 inst->alg.init = crypto_rfc4309_init_tfm;
875 inst->alg.exit = crypto_rfc4309_exit_tfm;
876
877 inst->alg.setkey = crypto_rfc4309_setkey;
878 inst->alg.setauthsize = crypto_rfc4309_setauthsize;
879 inst->alg.encrypt = crypto_rfc4309_encrypt;
880 inst->alg.decrypt = crypto_rfc4309_decrypt;
881
882 inst->free = crypto_rfc4309_free;
883
884 err = aead_register_instance(tmpl, inst);
885 if (err)
886 goto out_drop_alg;
887
888 out:
889 return err;
890
891 out_drop_alg:
892 crypto_drop_aead(spawn);
893 out_free_inst:
894 kfree(inst);
895 goto out;
896 }
897
898 static struct crypto_template crypto_rfc4309_tmpl = {
899 .name = "rfc4309",
900 .create = crypto_rfc4309_create,
901 .module = THIS_MODULE,
902 };
903
crypto_ccm_module_init(void)904 static int __init crypto_ccm_module_init(void)
905 {
906 int err;
907
908 err = crypto_register_template(&crypto_ccm_base_tmpl);
909 if (err)
910 goto out;
911
912 err = crypto_register_template(&crypto_ccm_tmpl);
913 if (err)
914 goto out_undo_base;
915
916 err = crypto_register_template(&crypto_rfc4309_tmpl);
917 if (err)
918 goto out_undo_ccm;
919
920 out:
921 return err;
922
923 out_undo_ccm:
924 crypto_unregister_template(&crypto_ccm_tmpl);
925 out_undo_base:
926 crypto_unregister_template(&crypto_ccm_base_tmpl);
927 goto out;
928 }
929
crypto_ccm_module_exit(void)930 static void __exit crypto_ccm_module_exit(void)
931 {
932 crypto_unregister_template(&crypto_rfc4309_tmpl);
933 crypto_unregister_template(&crypto_ccm_tmpl);
934 crypto_unregister_template(&crypto_ccm_base_tmpl);
935 }
936
937 module_init(crypto_ccm_module_init);
938 module_exit(crypto_ccm_module_exit);
939
940 MODULE_LICENSE("GPL");
941 MODULE_DESCRIPTION("Counter with CBC MAC");
942 MODULE_ALIAS_CRYPTO("ccm_base");
943 MODULE_ALIAS_CRYPTO("rfc4309");
944 MODULE_ALIAS_CRYPTO("ccm");
945