blob: b3ace633fae92a09c1e3f86876eb137b21b4b729
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
804 | static void crypto_rfc4309_free(struct aead_instance *inst) |
805 | { |
806 | crypto_drop_aead(aead_instance_ctx(inst)); |
807 | kfree(inst); |
808 | } |
809 | |
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 | |
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 | |
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 |