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
crypto_ccm_reqctx(struct aead_request * req)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
set_msg_len(u8 * block,unsigned int msglen,int csize)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
crypto_ccm_setkey(struct crypto_aead * aead,const u8 * key,unsigned int keylen)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
crypto_ccm_setauthsize(struct crypto_aead * tfm,unsigned int authsize)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
format_input(u8 * info,struct aead_request * req,unsigned int cryptlen)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
format_adata(u8 * adata,unsigned int a)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
compute_mac(struct crypto_cipher * tfm,u8 * data,int n,struct crypto_ccm_req_priv_ctx * pctx)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
get_data_to_compute(struct crypto_cipher * tfm,struct crypto_ccm_req_priv_ctx * pctx,struct scatterlist * sg,unsigned int len)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
crypto_ccm_auth(struct aead_request * req,struct scatterlist * plain,unsigned int cryptlen)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 } else {
270 pctx->ilen = 0;
271 }
272
273 /* compute plaintext into mac */
274 get_data_to_compute(cipher, pctx, plain, cryptlen);
275
276 out:
277 return err;
278 }
279
crypto_ccm_encrypt_done(struct crypto_async_request * areq,int err)280 static 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
crypto_ccm_check_iv(const u8 * iv)293 static 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
crypto_ccm_encrypt(struct aead_request * req)302 static 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
crypto_ccm_decrypt_done(struct crypto_async_request * areq,int err)355 static 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
crypto_ccm_decrypt(struct aead_request * req)372 static 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
crypto_ccm_init_tfm(struct crypto_tfm * tfm)431 static 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
461 err_free_cipher:
462 crypto_free_cipher(cipher);
463 return err;
464 }
465
crypto_ccm_exit_tfm(struct crypto_tfm * tfm)466 static 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
crypto_ccm_alloc_common(struct rtattr ** tb,const char * full_name,const char * ctr_name,const char * cipher_name)474 static 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
559 out:
560 crypto_mod_put(cipher);
561 return inst;
562
563 err_drop_ctr:
564 crypto_drop_skcipher(&ictx->ctr);
565 err_drop_cipher:
566 crypto_drop_spawn(&ictx->cipher);
567 err_free_inst:
568 kfree(inst);
569 out_put_cipher:
570 inst = ERR_PTR(err);
571 goto out;
572 }
573
crypto_ccm_alloc(struct rtattr ** tb)574 static 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
crypto_ccm_free(struct crypto_instance * inst)597 static 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
606 static 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
crypto_ccm_base_alloc(struct rtattr ** tb)613 static 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
637 static 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
crypto_rfc4309_setkey(struct crypto_aead * parent,const u8 * key,unsigned int keylen)644 static 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
crypto_rfc4309_setauthsize(struct crypto_aead * parent,unsigned int authsize)667 static 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
crypto_rfc4309_crypt(struct aead_request * req)684 static 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
crypto_rfc4309_encrypt(struct aead_request * req)708 static int crypto_rfc4309_encrypt(struct aead_request *req)
709 {
710 req = crypto_rfc4309_crypt(req);
711
712 return crypto_aead_encrypt(req);
713 }
714
crypto_rfc4309_decrypt(struct aead_request * req)715 static int crypto_rfc4309_decrypt(struct aead_request *req)
716 {
717 req = crypto_rfc4309_crypt(req);
718
719 return crypto_aead_decrypt(req);
720 }
721
crypto_rfc4309_init_tfm(struct crypto_tfm * tfm)722 static 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
crypto_rfc4309_exit_tfm(struct crypto_tfm * tfm)746 static 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
crypto_rfc4309_alloc(struct rtattr ** tb)753 static 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
828 out:
829 return inst;
830
831 out_drop_alg:
832 crypto_drop_aead(spawn);
833 out_free_inst:
834 kfree(inst);
835 inst = ERR_PTR(err);
836 goto out;
837 }
838
crypto_rfc4309_free(struct crypto_instance * inst)839 static void crypto_rfc4309_free(struct crypto_instance *inst)
840 {
841 crypto_drop_spawn(crypto_instance_ctx(inst));
842 kfree(inst);
843 }
844
845 static 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
crypto_ccm_module_init(void)852 static 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
868 out:
869 return err;
870
871 out_undo_ccm:
872 crypto_unregister_template(&crypto_ccm_tmpl);
873 out_undo_base:
874 crypto_unregister_template(&crypto_ccm_base_tmpl);
875 goto out;
876 }
877
crypto_ccm_module_exit(void)878 static 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
885 module_init(crypto_ccm_module_init);
886 module_exit(crypto_ccm_module_exit);
887
888 MODULE_LICENSE("GPL");
889 MODULE_DESCRIPTION("Counter with CBC MAC");
890 MODULE_ALIAS("ccm_base");
891 MODULE_ALIAS("rfc4309");
892