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_ablkcipher *ctr;
32 };
33
34 struct crypto_rfc4309_ctx {
35 struct crypto_aead *child;
36 u8 nonce[3];
37 };
38
39 struct 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
50 static 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
58 static 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
76 static 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
100 out:
101 return err;
102 }
103
104 static 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
123 static 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
145 static 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
164 static 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
203 static 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
245 static 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 }
270
271 /* compute plaintext into mac */
272 get_data_to_compute(cipher, pctx, plain, cryptlen);
273
274 out:
275 return err;
276 }
277
278 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
279 {
280 struct aead_request *req = areq->data;
281 struct crypto_aead *aead = crypto_aead_reqtfm(req);
282 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
283 u8 *odata = pctx->odata;
284
285 if (!err)
286 scatterwalk_map_and_copy(odata, req->dst, req->cryptlen,
287 crypto_aead_authsize(aead), 1);
288 aead_request_complete(req, err);
289 }
290
291 static inline int crypto_ccm_check_iv(const u8 *iv)
292 {
293 /* 2 <= L <= 8, so 1 <= L' <= 7. */
294 if (1 > iv[0] || iv[0] > 7)
295 return -EINVAL;
296
297 return 0;
298 }
299
300 static int crypto_ccm_encrypt(struct aead_request *req)
301 {
302 struct crypto_aead *aead = crypto_aead_reqtfm(req);
303 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
304 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
305 struct ablkcipher_request *abreq = &pctx->abreq;
306 struct scatterlist *dst;
307 unsigned int cryptlen = req->cryptlen;
308 u8 *odata = pctx->odata;
309 u8 *iv = req->iv;
310 int err;
311
312 err = crypto_ccm_check_iv(iv);
313 if (err)
314 return err;
315
316 pctx->flags = aead_request_flags(req);
317
318 err = crypto_ccm_auth(req, req->src, cryptlen);
319 if (err)
320 return err;
321
322 /* Note: rfc 3610 and NIST 800-38C require counter of
323 * zero to encrypt auth tag.
324 */
325 memset(iv + 15 - iv[0], 0, iv[0] + 1);
326
327 sg_init_table(pctx->src, 2);
328 sg_set_buf(pctx->src, odata, 16);
329 scatterwalk_sg_chain(pctx->src, 2, req->src);
330
331 dst = pctx->src;
332 if (req->src != req->dst) {
333 sg_init_table(pctx->dst, 2);
334 sg_set_buf(pctx->dst, odata, 16);
335 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
336 dst = pctx->dst;
337 }
338
339 ablkcipher_request_set_tfm(abreq, ctx->ctr);
340 ablkcipher_request_set_callback(abreq, pctx->flags,
341 crypto_ccm_encrypt_done, req);
342 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
343 err = crypto_ablkcipher_encrypt(abreq);
344 if (err)
345 return err;
346
347 /* copy authtag to end of dst */
348 scatterwalk_map_and_copy(odata, req->dst, cryptlen,
349 crypto_aead_authsize(aead), 1);
350 return err;
351 }
352
353 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
354 int err)
355 {
356 struct aead_request *req = areq->data;
357 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
358 struct crypto_aead *aead = crypto_aead_reqtfm(req);
359 unsigned int authsize = crypto_aead_authsize(aead);
360 unsigned int cryptlen = req->cryptlen - authsize;
361
362 if (!err) {
363 err = crypto_ccm_auth(req, req->dst, cryptlen);
364 if (!err && memcmp(pctx->auth_tag, pctx->odata, authsize))
365 err = -EBADMSG;
366 }
367 aead_request_complete(req, err);
368 }
369
370 static int crypto_ccm_decrypt(struct aead_request *req)
371 {
372 struct crypto_aead *aead = crypto_aead_reqtfm(req);
373 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
374 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
375 struct ablkcipher_request *abreq = &pctx->abreq;
376 struct scatterlist *dst;
377 unsigned int authsize = crypto_aead_authsize(aead);
378 unsigned int cryptlen = req->cryptlen;
379 u8 *authtag = pctx->auth_tag;
380 u8 *odata = pctx->odata;
381 u8 *iv = req->iv;
382 int err;
383
384 if (cryptlen < authsize)
385 return -EINVAL;
386 cryptlen -= authsize;
387
388 err = crypto_ccm_check_iv(iv);
389 if (err)
390 return err;
391
392 pctx->flags = aead_request_flags(req);
393
394 scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0);
395
396 memset(iv + 15 - iv[0], 0, iv[0] + 1);
397
398 sg_init_table(pctx->src, 2);
399 sg_set_buf(pctx->src, authtag, 16);
400 scatterwalk_sg_chain(pctx->src, 2, req->src);
401
402 dst = pctx->src;
403 if (req->src != req->dst) {
404 sg_init_table(pctx->dst, 2);
405 sg_set_buf(pctx->dst, authtag, 16);
406 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
407 dst = pctx->dst;
408 }
409
410 ablkcipher_request_set_tfm(abreq, ctx->ctr);
411 ablkcipher_request_set_callback(abreq, pctx->flags,
412 crypto_ccm_decrypt_done, req);
413 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv);
414 err = crypto_ablkcipher_decrypt(abreq);
415 if (err)
416 return err;
417
418 err = crypto_ccm_auth(req, req->dst, cryptlen);
419 if (err)
420 return err;
421
422 /* verify */
423 if (memcmp(authtag, odata, authsize))
424 return -EBADMSG;
425
426 return err;
427 }
428
429 static int crypto_ccm_init_tfm(struct crypto_tfm *tfm)
430 {
431 struct crypto_instance *inst = (void *)tfm->__crt_alg;
432 struct ccm_instance_ctx *ictx = crypto_instance_ctx(inst);
433 struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
434 struct crypto_cipher *cipher;
435 struct crypto_ablkcipher *ctr;
436 unsigned long align;
437 int err;
438
439 cipher = crypto_spawn_cipher(&ictx->cipher);
440 if (IS_ERR(cipher))
441 return PTR_ERR(cipher);
442
443 ctr = crypto_spawn_skcipher(&ictx->ctr);
444 err = PTR_ERR(ctr);
445 if (IS_ERR(ctr))
446 goto err_free_cipher;
447
448 ctx->cipher = cipher;
449 ctx->ctr = ctr;
450
451 align = crypto_tfm_alg_alignmask(tfm);
452 align &= ~(crypto_tfm_ctx_alignment() - 1);
453 tfm->crt_aead.reqsize = align +
454 sizeof(struct crypto_ccm_req_priv_ctx) +
455 crypto_ablkcipher_reqsize(ctr);
456
457 return 0;
458
459 err_free_cipher:
460 crypto_free_cipher(cipher);
461 return err;
462 }
463
464 static void crypto_ccm_exit_tfm(struct crypto_tfm *tfm)
465 {
466 struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm);
467
468 crypto_free_cipher(ctx->cipher);
469 crypto_free_ablkcipher(ctx->ctr);
470 }
471
472 static struct crypto_instance *crypto_ccm_alloc_common(struct rtattr **tb,
473 const char *full_name,
474 const char *ctr_name,
475 const char *cipher_name)
476 {
477 struct crypto_attr_type *algt;
478 struct crypto_instance *inst;
479 struct crypto_alg *ctr;
480 struct crypto_alg *cipher;
481 struct ccm_instance_ctx *ictx;
482 int err;
483
484 algt = crypto_get_attr_type(tb);
485 err = PTR_ERR(algt);
486 if (IS_ERR(algt))
487 return ERR_PTR(err);
488
489 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
490 return ERR_PTR(-EINVAL);
491
492 cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER,
493 CRYPTO_ALG_TYPE_MASK);
494 err = PTR_ERR(cipher);
495 if (IS_ERR(cipher))
496 return ERR_PTR(err);
497
498 err = -EINVAL;
499 if (cipher->cra_blocksize != 16)
500 goto out_put_cipher;
501
502 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
503 err = -ENOMEM;
504 if (!inst)
505 goto out_put_cipher;
506
507 ictx = crypto_instance_ctx(inst);
508
509 err = crypto_init_spawn(&ictx->cipher, cipher, inst,
510 CRYPTO_ALG_TYPE_MASK);
511 if (err)
512 goto err_free_inst;
513
514 crypto_set_skcipher_spawn(&ictx->ctr, inst);
515 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
516 crypto_requires_sync(algt->type,
517 algt->mask));
518 if (err)
519 goto err_drop_cipher;
520
521 ctr = crypto_skcipher_spawn_alg(&ictx->ctr);
522
523 /* Not a stream cipher? */
524 err = -EINVAL;
525 if (ctr->cra_blocksize != 1)
526 goto err_drop_ctr;
527
528 /* We want the real thing! */
529 if (ctr->cra_ablkcipher.ivsize != 16)
530 goto err_drop_ctr;
531
532 err = -ENAMETOOLONG;
533 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
534 "ccm_base(%s,%s)", ctr->cra_driver_name,
535 cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
536 goto err_drop_ctr;
537
538 memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
539
540 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
541 inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
542 inst->alg.cra_priority = cipher->cra_priority + ctr->cra_priority;
543 inst->alg.cra_blocksize = 1;
544 inst->alg.cra_alignmask = cipher->cra_alignmask | ctr->cra_alignmask |
545 (__alignof__(u32) - 1);
546 inst->alg.cra_type = &crypto_aead_type;
547 inst->alg.cra_aead.ivsize = 16;
548 inst->alg.cra_aead.maxauthsize = 16;
549 inst->alg.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
550 inst->alg.cra_init = crypto_ccm_init_tfm;
551 inst->alg.cra_exit = crypto_ccm_exit_tfm;
552 inst->alg.cra_aead.setkey = crypto_ccm_setkey;
553 inst->alg.cra_aead.setauthsize = crypto_ccm_setauthsize;
554 inst->alg.cra_aead.encrypt = crypto_ccm_encrypt;
555 inst->alg.cra_aead.decrypt = crypto_ccm_decrypt;
556
557 out:
558 crypto_mod_put(cipher);
559 return inst;
560
561 err_drop_ctr:
562 crypto_drop_skcipher(&ictx->ctr);
563 err_drop_cipher:
564 crypto_drop_spawn(&ictx->cipher);
565 err_free_inst:
566 kfree(inst);
567 out_put_cipher:
568 inst = ERR_PTR(err);
569 goto out;
570 }
571
572 static struct crypto_instance *crypto_ccm_alloc(struct rtattr **tb)
573 {
574 int err;
575 const char *cipher_name;
576 char ctr_name[CRYPTO_MAX_ALG_NAME];
577 char full_name[CRYPTO_MAX_ALG_NAME];
578
579 cipher_name = crypto_attr_alg_name(tb[1]);
580 err = PTR_ERR(cipher_name);
581 if (IS_ERR(cipher_name))
582 return ERR_PTR(err);
583
584 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
585 cipher_name) >= CRYPTO_MAX_ALG_NAME)
586 return ERR_PTR(-ENAMETOOLONG);
587
588 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
589 CRYPTO_MAX_ALG_NAME)
590 return ERR_PTR(-ENAMETOOLONG);
591
592 return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
593 }
594
595 static void crypto_ccm_free(struct crypto_instance *inst)
596 {
597 struct ccm_instance_ctx *ctx = crypto_instance_ctx(inst);
598
599 crypto_drop_spawn(&ctx->cipher);
600 crypto_drop_skcipher(&ctx->ctr);
601 kfree(inst);
602 }
603
604 static struct crypto_template crypto_ccm_tmpl = {
605 .name = "ccm",
606 .alloc = crypto_ccm_alloc,
607 .free = crypto_ccm_free,
608 .module = THIS_MODULE,
609 };
610
611 static struct crypto_instance *crypto_ccm_base_alloc(struct rtattr **tb)
612 {
613 int err;
614 const char *ctr_name;
615 const char *cipher_name;
616 char full_name[CRYPTO_MAX_ALG_NAME];
617
618 ctr_name = crypto_attr_alg_name(tb[1]);
619 err = PTR_ERR(ctr_name);
620 if (IS_ERR(ctr_name))
621 return ERR_PTR(err);
622
623 cipher_name = crypto_attr_alg_name(tb[2]);
624 err = PTR_ERR(cipher_name);
625 if (IS_ERR(cipher_name))
626 return ERR_PTR(err);
627
628 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
629 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
630 return ERR_PTR(-ENAMETOOLONG);
631
632 return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name);
633 }
634
635 static struct crypto_template crypto_ccm_base_tmpl = {
636 .name = "ccm_base",
637 .alloc = crypto_ccm_base_alloc,
638 .free = crypto_ccm_free,
639 .module = THIS_MODULE,
640 };
641
642 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
643 unsigned int keylen)
644 {
645 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
646 struct crypto_aead *child = ctx->child;
647 int err;
648
649 if (keylen < 3)
650 return -EINVAL;
651
652 keylen -= 3;
653 memcpy(ctx->nonce, key + keylen, 3);
654
655 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
656 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
657 CRYPTO_TFM_REQ_MASK);
658 err = crypto_aead_setkey(child, key, keylen);
659 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
660 CRYPTO_TFM_RES_MASK);
661
662 return err;
663 }
664
665 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
666 unsigned int authsize)
667 {
668 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
669
670 switch (authsize) {
671 case 8:
672 case 12:
673 case 16:
674 break;
675 default:
676 return -EINVAL;
677 }
678
679 return crypto_aead_setauthsize(ctx->child, authsize);
680 }
681
682 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
683 {
684 struct aead_request *subreq = aead_request_ctx(req);
685 struct crypto_aead *aead = crypto_aead_reqtfm(req);
686 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
687 struct crypto_aead *child = ctx->child;
688 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
689 crypto_aead_alignmask(child) + 1);
690
691 /* L' */
692 iv[0] = 3;
693
694 memcpy(iv + 1, ctx->nonce, 3);
695 memcpy(iv + 4, req->iv, 8);
696
697 aead_request_set_tfm(subreq, child);
698 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
699 req->base.data);
700 aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
701 aead_request_set_assoc(subreq, req->assoc, req->assoclen);
702
703 return subreq;
704 }
705
706 static int crypto_rfc4309_encrypt(struct aead_request *req)
707 {
708 req = crypto_rfc4309_crypt(req);
709
710 return crypto_aead_encrypt(req);
711 }
712
713 static int crypto_rfc4309_decrypt(struct aead_request *req)
714 {
715 req = crypto_rfc4309_crypt(req);
716
717 return crypto_aead_decrypt(req);
718 }
719
720 static int crypto_rfc4309_init_tfm(struct crypto_tfm *tfm)
721 {
722 struct crypto_instance *inst = (void *)tfm->__crt_alg;
723 struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
724 struct crypto_rfc4309_ctx *ctx = crypto_tfm_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 tfm->crt_aead.reqsize = sizeof(struct aead_request) +
737 ALIGN(crypto_aead_reqsize(aead),
738 crypto_tfm_ctx_alignment()) +
739 align + 16;
740
741 return 0;
742 }
743
744 static void crypto_rfc4309_exit_tfm(struct crypto_tfm *tfm)
745 {
746 struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm);
747
748 crypto_free_aead(ctx->child);
749 }
750
751 static struct crypto_instance *crypto_rfc4309_alloc(struct rtattr **tb)
752 {
753 struct crypto_attr_type *algt;
754 struct crypto_instance *inst;
755 struct crypto_aead_spawn *spawn;
756 struct crypto_alg *alg;
757 const char *ccm_name;
758 int err;
759
760 algt = crypto_get_attr_type(tb);
761 err = PTR_ERR(algt);
762 if (IS_ERR(algt))
763 return ERR_PTR(err);
764
765 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
766 return ERR_PTR(-EINVAL);
767
768 ccm_name = crypto_attr_alg_name(tb[1]);
769 err = PTR_ERR(ccm_name);
770 if (IS_ERR(ccm_name))
771 return ERR_PTR(err);
772
773 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
774 if (!inst)
775 return ERR_PTR(-ENOMEM);
776
777 spawn = crypto_instance_ctx(inst);
778 crypto_set_aead_spawn(spawn, inst);
779 err = crypto_grab_aead(spawn, ccm_name, 0,
780 crypto_requires_sync(algt->type, algt->mask));
781 if (err)
782 goto out_free_inst;
783
784 alg = crypto_aead_spawn_alg(spawn);
785
786 err = -EINVAL;
787
788 /* We only support 16-byte blocks. */
789 if (alg->cra_aead.ivsize != 16)
790 goto out_drop_alg;
791
792 /* Not a stream cipher? */
793 if (alg->cra_blocksize != 1)
794 goto out_drop_alg;
795
796 err = -ENAMETOOLONG;
797 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
798 "rfc4309(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
799 snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
800 "rfc4309(%s)", alg->cra_driver_name) >=
801 CRYPTO_MAX_ALG_NAME)
802 goto out_drop_alg;
803
804 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
805 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
806 inst->alg.cra_priority = alg->cra_priority;
807 inst->alg.cra_blocksize = 1;
808 inst->alg.cra_alignmask = alg->cra_alignmask;
809 inst->alg.cra_type = &crypto_nivaead_type;
810
811 inst->alg.cra_aead.ivsize = 8;
812 inst->alg.cra_aead.maxauthsize = 16;
813
814 inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
815
816 inst->alg.cra_init = crypto_rfc4309_init_tfm;
817 inst->alg.cra_exit = crypto_rfc4309_exit_tfm;
818
819 inst->alg.cra_aead.setkey = crypto_rfc4309_setkey;
820 inst->alg.cra_aead.setauthsize = crypto_rfc4309_setauthsize;
821 inst->alg.cra_aead.encrypt = crypto_rfc4309_encrypt;
822 inst->alg.cra_aead.decrypt = crypto_rfc4309_decrypt;
823
824 inst->alg.cra_aead.geniv = "seqiv";
825
826 out:
827 return inst;
828
829 out_drop_alg:
830 crypto_drop_aead(spawn);
831 out_free_inst:
832 kfree(inst);
833 inst = ERR_PTR(err);
834 goto out;
835 }
836
837 static void crypto_rfc4309_free(struct crypto_instance *inst)
838 {
839 crypto_drop_spawn(crypto_instance_ctx(inst));
840 kfree(inst);
841 }
842
843 static struct crypto_template crypto_rfc4309_tmpl = {
844 .name = "rfc4309",
845 .alloc = crypto_rfc4309_alloc,
846 .free = crypto_rfc4309_free,
847 .module = THIS_MODULE,
848 };
849
850 static int __init crypto_ccm_module_init(void)
851 {
852 int err;
853
854 err = crypto_register_template(&crypto_ccm_base_tmpl);
855 if (err)
856 goto out;
857
858 err = crypto_register_template(&crypto_ccm_tmpl);
859 if (err)
860 goto out_undo_base;
861
862 err = crypto_register_template(&crypto_rfc4309_tmpl);
863 if (err)
864 goto out_undo_ccm;
865
866 out:
867 return err;
868
869 out_undo_ccm:
870 crypto_unregister_template(&crypto_ccm_tmpl);
871 out_undo_base:
872 crypto_unregister_template(&crypto_ccm_base_tmpl);
873 goto out;
874 }
875
876 static void __exit crypto_ccm_module_exit(void)
877 {
878 crypto_unregister_template(&crypto_rfc4309_tmpl);
879 crypto_unregister_template(&crypto_ccm_tmpl);
880 crypto_unregister_template(&crypto_ccm_base_tmpl);
881 }
882
883 module_init(crypto_ccm_module_init);
884 module_exit(crypto_ccm_module_exit);
885
886 MODULE_LICENSE("GPL");
887 MODULE_DESCRIPTION("Counter with CBC MAC");
888 MODULE_ALIAS("ccm_base");
889 MODULE_ALIAS("rfc4309");
890
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