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1/*
2 * Authenc: Simple AEAD wrapper for IPsec
3 *
4 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
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/aead.h>
14#include <crypto/internal/hash.h>
15#include <crypto/internal/skcipher.h>
16#include <crypto/authenc.h>
17#include <crypto/scatterwalk.h>
18#include <linux/err.h>
19#include <linux/init.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/rtnetlink.h>
23#include <linux/slab.h>
24#include <linux/spinlock.h>
25
26typedef u8 *(*authenc_ahash_t)(struct aead_request *req, unsigned int flags);
27
28struct authenc_instance_ctx {
29 struct crypto_ahash_spawn auth;
30 struct crypto_skcipher_spawn enc;
31};
32
33struct crypto_authenc_ctx {
34 unsigned int reqoff;
35 struct crypto_ahash *auth;
36 struct crypto_ablkcipher *enc;
37};
38
39struct authenc_request_ctx {
40 unsigned int cryptlen;
41 struct scatterlist *sg;
42 struct scatterlist asg[2];
43 struct scatterlist cipher[2];
44 crypto_completion_t complete;
45 crypto_completion_t update_complete;
46 char tail[];
47};
48
49static void authenc_request_complete(struct aead_request *req, int err)
50{
51 if (err != -EINPROGRESS)
52 aead_request_complete(req, err);
53}
54
55int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
56 unsigned int keylen)
57{
58 struct rtattr *rta = (struct rtattr *)key;
59 struct crypto_authenc_key_param *param;
60
61 if (!RTA_OK(rta, keylen))
62 return -EINVAL;
63 if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
64 return -EINVAL;
65 if (RTA_PAYLOAD(rta) < sizeof(*param))
66 return -EINVAL;
67
68 param = RTA_DATA(rta);
69 keys->enckeylen = be32_to_cpu(param->enckeylen);
70
71 key += RTA_ALIGN(rta->rta_len);
72 keylen -= RTA_ALIGN(rta->rta_len);
73
74 if (keylen < keys->enckeylen)
75 return -EINVAL;
76
77 keys->authkeylen = keylen - keys->enckeylen;
78 keys->authkey = key;
79 keys->enckey = key + keys->authkeylen;
80
81 return 0;
82}
83EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
84
85static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
86 unsigned int keylen)
87{
88 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
89 struct crypto_ahash *auth = ctx->auth;
90 struct crypto_ablkcipher *enc = ctx->enc;
91 struct crypto_authenc_keys keys;
92 int err = -EINVAL;
93
94 if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
95 goto badkey;
96
97 crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
98 crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
99 CRYPTO_TFM_REQ_MASK);
100 err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
101 crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
102 CRYPTO_TFM_RES_MASK);
103
104 if (err)
105 goto out;
106
107 crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
108 crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
109 CRYPTO_TFM_REQ_MASK);
110 err = crypto_ablkcipher_setkey(enc, keys.enckey, keys.enckeylen);
111 crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
112 CRYPTO_TFM_RES_MASK);
113
114out:
115 return err;
116
117badkey:
118 crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
119 goto out;
120}
121
122static void authenc_geniv_ahash_update_done(struct crypto_async_request *areq,
123 int err)
124{
125 struct aead_request *req = areq->data;
126 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
127 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
128 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
129 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
130
131 if (err)
132 goto out;
133
134 ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
135 areq_ctx->cryptlen);
136 ahash_request_set_callback(ahreq, aead_request_flags(req) &
137 CRYPTO_TFM_REQ_MAY_SLEEP,
138 areq_ctx->complete, req);
139
140 err = crypto_ahash_finup(ahreq);
141 if (err)
142 goto out;
143
144 scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
145 areq_ctx->cryptlen,
146 crypto_aead_authsize(authenc), 1);
147
148out:
149 authenc_request_complete(req, err);
150}
151
152static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
153{
154 struct aead_request *req = areq->data;
155 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
156 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
157 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
158 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
159
160 if (err)
161 goto out;
162
163 scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
164 areq_ctx->cryptlen,
165 crypto_aead_authsize(authenc), 1);
166
167out:
168 aead_request_complete(req, err);
169}
170
171static void authenc_verify_ahash_update_done(struct crypto_async_request *areq,
172 int err)
173{
174 u8 *ihash;
175 unsigned int authsize;
176 struct ablkcipher_request *abreq;
177 struct aead_request *req = areq->data;
178 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
179 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
180 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
181 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
182 unsigned int cryptlen = req->cryptlen;
183
184 if (err)
185 goto out;
186
187 ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
188 areq_ctx->cryptlen);
189 ahash_request_set_callback(ahreq, aead_request_flags(req) &
190 CRYPTO_TFM_REQ_MAY_SLEEP,
191 areq_ctx->complete, req);
192
193 err = crypto_ahash_finup(ahreq);
194 if (err)
195 goto out;
196
197 authsize = crypto_aead_authsize(authenc);
198 cryptlen -= authsize;
199 ihash = ahreq->result + authsize;
200 scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
201 authsize, 0);
202
203 err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
204 if (err)
205 goto out;
206
207 abreq = aead_request_ctx(req);
208 ablkcipher_request_set_tfm(abreq, ctx->enc);
209 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
210 req->base.complete, req->base.data);
211 ablkcipher_request_set_crypt(abreq, req->src, req->dst,
212 cryptlen, req->iv);
213
214 err = crypto_ablkcipher_decrypt(abreq);
215
216out:
217 authenc_request_complete(req, err);
218}
219
220static void authenc_verify_ahash_done(struct crypto_async_request *areq,
221 int err)
222{
223 u8 *ihash;
224 unsigned int authsize;
225 struct ablkcipher_request *abreq;
226 struct aead_request *req = areq->data;
227 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
228 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
229 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
230 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
231 unsigned int cryptlen = req->cryptlen;
232
233 if (err)
234 goto out;
235
236 authsize = crypto_aead_authsize(authenc);
237 cryptlen -= authsize;
238 ihash = ahreq->result + authsize;
239 scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
240 authsize, 0);
241
242 err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
243 if (err)
244 goto out;
245
246 abreq = aead_request_ctx(req);
247 ablkcipher_request_set_tfm(abreq, ctx->enc);
248 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
249 req->base.complete, req->base.data);
250 ablkcipher_request_set_crypt(abreq, req->src, req->dst,
251 cryptlen, req->iv);
252
253 err = crypto_ablkcipher_decrypt(abreq);
254
255out:
256 authenc_request_complete(req, err);
257}
258
259static u8 *crypto_authenc_ahash_fb(struct aead_request *req, unsigned int flags)
260{
261 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
262 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
263 struct crypto_ahash *auth = ctx->auth;
264 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
265 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
266 u8 *hash = areq_ctx->tail;
267 int err;
268
269 hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
270 crypto_ahash_alignmask(auth) + 1);
271
272 ahash_request_set_tfm(ahreq, auth);
273
274 err = crypto_ahash_init(ahreq);
275 if (err)
276 return ERR_PTR(err);
277
278 ahash_request_set_crypt(ahreq, req->assoc, hash, req->assoclen);
279 ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
280 areq_ctx->update_complete, req);
281
282 err = crypto_ahash_update(ahreq);
283 if (err)
284 return ERR_PTR(err);
285
286 ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
287 areq_ctx->cryptlen);
288 ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
289 areq_ctx->complete, req);
290
291 err = crypto_ahash_finup(ahreq);
292 if (err)
293 return ERR_PTR(err);
294
295 return hash;
296}
297
298static u8 *crypto_authenc_ahash(struct aead_request *req, unsigned int flags)
299{
300 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
301 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
302 struct crypto_ahash *auth = ctx->auth;
303 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
304 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
305 u8 *hash = areq_ctx->tail;
306 int err;
307
308 hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
309 crypto_ahash_alignmask(auth) + 1);
310
311 ahash_request_set_tfm(ahreq, auth);
312 ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
313 areq_ctx->cryptlen);
314 ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
315 areq_ctx->complete, req);
316
317 err = crypto_ahash_digest(ahreq);
318 if (err)
319 return ERR_PTR(err);
320
321 return hash;
322}
323
324static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
325 unsigned int flags)
326{
327 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
328 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
329 struct scatterlist *dst = req->dst;
330 struct scatterlist *assoc = req->assoc;
331 struct scatterlist *cipher = areq_ctx->cipher;
332 struct scatterlist *asg = areq_ctx->asg;
333 unsigned int ivsize = crypto_aead_ivsize(authenc);
334 unsigned int cryptlen = req->cryptlen;
335 authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
336 struct page *dstp;
337 u8 *vdst;
338 u8 *hash;
339
340 dstp = sg_page(dst);
341 vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
342
343 if (ivsize) {
344 sg_init_table(cipher, 2);
345 sg_set_buf(cipher, iv, ivsize);
346 scatterwalk_crypto_chain(cipher, dst, vdst == iv + ivsize, 2);
347 dst = cipher;
348 cryptlen += ivsize;
349 }
350
351 if (req->assoclen && sg_is_last(assoc)) {
352 authenc_ahash_fn = crypto_authenc_ahash;
353 sg_init_table(asg, 2);
354 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
355 scatterwalk_crypto_chain(asg, dst, 0, 2);
356 dst = asg;
357 cryptlen += req->assoclen;
358 }
359
360 areq_ctx->cryptlen = cryptlen;
361 areq_ctx->sg = dst;
362
363 areq_ctx->complete = authenc_geniv_ahash_done;
364 areq_ctx->update_complete = authenc_geniv_ahash_update_done;
365
366 hash = authenc_ahash_fn(req, flags);
367 if (IS_ERR(hash))
368 return PTR_ERR(hash);
369
370 scatterwalk_map_and_copy(hash, dst, cryptlen,
371 crypto_aead_authsize(authenc), 1);
372 return 0;
373}
374
375static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
376 int err)
377{
378 struct aead_request *areq = req->data;
379
380 if (!err) {
381 struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
382 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
383 struct authenc_request_ctx *areq_ctx = aead_request_ctx(areq);
384 struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
385 + ctx->reqoff);
386 u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(ctx->enc);
387
388 err = crypto_authenc_genicv(areq, iv, 0);
389 }
390
391 authenc_request_complete(areq, err);
392}
393
394static int crypto_authenc_encrypt(struct aead_request *req)
395{
396 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
397 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
398 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
399 struct crypto_ablkcipher *enc = ctx->enc;
400 struct scatterlist *dst = req->dst;
401 unsigned int cryptlen = req->cryptlen;
402 struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
403 + ctx->reqoff);
404 u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
405 int err;
406
407 ablkcipher_request_set_tfm(abreq, enc);
408 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
409 crypto_authenc_encrypt_done, req);
410 ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
411
412 memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
413
414 err = crypto_ablkcipher_encrypt(abreq);
415 if (err)
416 return err;
417
418 return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
419}
420
421static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
422 int err)
423{
424 struct aead_request *areq = req->data;
425
426 if (!err) {
427 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
428
429 err = crypto_authenc_genicv(areq, greq->giv, 0);
430 }
431
432 authenc_request_complete(areq, err);
433}
434
435static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
436{
437 struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
438 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
439 struct aead_request *areq = &req->areq;
440 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
441 u8 *iv = req->giv;
442 int err;
443
444 skcipher_givcrypt_set_tfm(greq, ctx->enc);
445 skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
446 crypto_authenc_givencrypt_done, areq);
447 skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
448 areq->iv);
449 skcipher_givcrypt_set_giv(greq, iv, req->seq);
450
451 err = crypto_skcipher_givencrypt(greq);
452 if (err)
453 return err;
454
455 return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
456}
457
458static int crypto_authenc_verify(struct aead_request *req,
459 authenc_ahash_t authenc_ahash_fn)
460{
461 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
462 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
463 u8 *ohash;
464 u8 *ihash;
465 unsigned int authsize;
466
467 areq_ctx->complete = authenc_verify_ahash_done;
468 areq_ctx->update_complete = authenc_verify_ahash_update_done;
469
470 ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
471 if (IS_ERR(ohash))
472 return PTR_ERR(ohash);
473
474 authsize = crypto_aead_authsize(authenc);
475 ihash = ohash + authsize;
476 scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
477 authsize, 0);
478 return crypto_memneq(ihash, ohash, authsize) ? -EBADMSG : 0;
479}
480
481static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
482 unsigned int cryptlen)
483{
484 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
485 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
486 struct scatterlist *src = req->src;
487 struct scatterlist *assoc = req->assoc;
488 struct scatterlist *cipher = areq_ctx->cipher;
489 struct scatterlist *asg = areq_ctx->asg;
490 unsigned int ivsize = crypto_aead_ivsize(authenc);
491 authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
492 struct page *srcp;
493 u8 *vsrc;
494
495 srcp = sg_page(src);
496 vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
497
498 if (ivsize) {
499 sg_init_table(cipher, 2);
500 sg_set_buf(cipher, iv, ivsize);
501 scatterwalk_crypto_chain(cipher, src, vsrc == iv + ivsize, 2);
502 src = cipher;
503 cryptlen += ivsize;
504 }
505
506 if (req->assoclen && sg_is_last(assoc)) {
507 authenc_ahash_fn = crypto_authenc_ahash;
508 sg_init_table(asg, 2);
509 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
510 scatterwalk_crypto_chain(asg, src, 0, 2);
511 src = asg;
512 cryptlen += req->assoclen;
513 }
514
515 areq_ctx->cryptlen = cryptlen;
516 areq_ctx->sg = src;
517
518 return crypto_authenc_verify(req, authenc_ahash_fn);
519}
520
521static int crypto_authenc_decrypt(struct aead_request *req)
522{
523 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
524 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
525 struct ablkcipher_request *abreq = aead_request_ctx(req);
526 unsigned int cryptlen = req->cryptlen;
527 unsigned int authsize = crypto_aead_authsize(authenc);
528 u8 *iv = req->iv;
529 int err;
530
531 if (cryptlen < authsize)
532 return -EINVAL;
533 cryptlen -= authsize;
534
535 err = crypto_authenc_iverify(req, iv, cryptlen);
536 if (err)
537 return err;
538
539 ablkcipher_request_set_tfm(abreq, ctx->enc);
540 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
541 req->base.complete, req->base.data);
542 ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
543
544 return crypto_ablkcipher_decrypt(abreq);
545}
546
547static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
548{
549 struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
550 struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
551 struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
552 struct crypto_ahash *auth;
553 struct crypto_ablkcipher *enc;
554 int err;
555
556 auth = crypto_spawn_ahash(&ictx->auth);
557 if (IS_ERR(auth))
558 return PTR_ERR(auth);
559
560 enc = crypto_spawn_skcipher(&ictx->enc);
561 err = PTR_ERR(enc);
562 if (IS_ERR(enc))
563 goto err_free_ahash;
564
565 ctx->auth = auth;
566 ctx->enc = enc;
567
568 ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
569 crypto_ahash_alignmask(auth),
570 crypto_ahash_alignmask(auth) + 1) +
571 crypto_ablkcipher_ivsize(enc);
572
573 tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
574 ctx->reqoff +
575 max_t(unsigned int,
576 crypto_ahash_reqsize(auth) +
577 sizeof(struct ahash_request),
578 sizeof(struct skcipher_givcrypt_request) +
579 crypto_ablkcipher_reqsize(enc));
580
581 return 0;
582
583err_free_ahash:
584 crypto_free_ahash(auth);
585 return err;
586}
587
588static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
589{
590 struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
591
592 crypto_free_ahash(ctx->auth);
593 crypto_free_ablkcipher(ctx->enc);
594}
595
596static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
597{
598 struct crypto_attr_type *algt;
599 struct crypto_instance *inst;
600 struct hash_alg_common *auth;
601 struct crypto_alg *auth_base;
602 struct crypto_alg *enc;
603 struct authenc_instance_ctx *ctx;
604 const char *enc_name;
605 int err;
606
607 algt = crypto_get_attr_type(tb);
608 if (IS_ERR(algt))
609 return ERR_CAST(algt);
610
611 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
612 return ERR_PTR(-EINVAL);
613
614 auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
615 CRYPTO_ALG_TYPE_AHASH_MASK);
616 if (IS_ERR(auth))
617 return ERR_CAST(auth);
618
619 auth_base = &auth->base;
620
621 enc_name = crypto_attr_alg_name(tb[2]);
622 err = PTR_ERR(enc_name);
623 if (IS_ERR(enc_name))
624 goto out_put_auth;
625
626 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
627 err = -ENOMEM;
628 if (!inst)
629 goto out_put_auth;
630
631 ctx = crypto_instance_ctx(inst);
632
633 err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
634 if (err)
635 goto err_free_inst;
636
637 crypto_set_skcipher_spawn(&ctx->enc, inst);
638 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
639 crypto_requires_sync(algt->type,
640 algt->mask));
641 if (err)
642 goto err_drop_auth;
643
644 enc = crypto_skcipher_spawn_alg(&ctx->enc);
645
646 err = -ENAMETOOLONG;
647 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
648 "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
649 CRYPTO_MAX_ALG_NAME)
650 goto err_drop_enc;
651
652 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
653 "authenc(%s,%s)", auth_base->cra_driver_name,
654 enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
655 goto err_drop_enc;
656
657 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
658 inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
659 inst->alg.cra_priority = enc->cra_priority *
660 10 + auth_base->cra_priority;
661 inst->alg.cra_blocksize = enc->cra_blocksize;
662 inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
663 inst->alg.cra_type = &crypto_aead_type;
664
665 inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
666 inst->alg.cra_aead.maxauthsize = auth->digestsize;
667
668 inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
669
670 inst->alg.cra_init = crypto_authenc_init_tfm;
671 inst->alg.cra_exit = crypto_authenc_exit_tfm;
672
673 inst->alg.cra_aead.setkey = crypto_authenc_setkey;
674 inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
675 inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
676 inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
677
678out:
679 crypto_mod_put(auth_base);
680 return inst;
681
682err_drop_enc:
683 crypto_drop_skcipher(&ctx->enc);
684err_drop_auth:
685 crypto_drop_ahash(&ctx->auth);
686err_free_inst:
687 kfree(inst);
688out_put_auth:
689 inst = ERR_PTR(err);
690 goto out;
691}
692
693static void crypto_authenc_free(struct crypto_instance *inst)
694{
695 struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
696
697 crypto_drop_skcipher(&ctx->enc);
698 crypto_drop_ahash(&ctx->auth);
699 kfree(inst);
700}
701
702static struct crypto_template crypto_authenc_tmpl = {
703 .name = "authenc",
704 .alloc = crypto_authenc_alloc,
705 .free = crypto_authenc_free,
706 .module = THIS_MODULE,
707};
708
709static int __init crypto_authenc_module_init(void)
710{
711 return crypto_register_template(&crypto_authenc_tmpl);
712}
713
714static void __exit crypto_authenc_module_exit(void)
715{
716 crypto_unregister_template(&crypto_authenc_tmpl);
717}
718
719module_init(crypto_authenc_module_init);
720module_exit(crypto_authenc_module_exit);
721
722MODULE_LICENSE("GPL");
723MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
1/*
2 * Authenc: Simple AEAD wrapper for IPsec
3 *
4 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#include <crypto/internal/aead.h>
14#include <crypto/internal/hash.h>
15#include <crypto/internal/skcipher.h>
16#include <crypto/authenc.h>
17#include <crypto/null.h>
18#include <crypto/scatterwalk.h>
19#include <linux/err.h>
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/rtnetlink.h>
24#include <linux/slab.h>
25#include <linux/spinlock.h>
26
27struct authenc_instance_ctx {
28 struct crypto_ahash_spawn auth;
29 struct crypto_skcipher_spawn enc;
30 unsigned int reqoff;
31};
32
33struct crypto_authenc_ctx {
34 struct crypto_ahash *auth;
35 struct crypto_ablkcipher *enc;
36 struct crypto_blkcipher *null;
37};
38
39struct authenc_request_ctx {
40 struct scatterlist src[2];
41 struct scatterlist dst[2];
42 char tail[];
43};
44
45static void authenc_request_complete(struct aead_request *req, int err)
46{
47 if (err != -EINPROGRESS)
48 aead_request_complete(req, err);
49}
50
51int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
52 unsigned int keylen)
53{
54 struct rtattr *rta = (struct rtattr *)key;
55 struct crypto_authenc_key_param *param;
56
57 if (!RTA_OK(rta, keylen))
58 return -EINVAL;
59 if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
60 return -EINVAL;
61 if (RTA_PAYLOAD(rta) < sizeof(*param))
62 return -EINVAL;
63
64 param = RTA_DATA(rta);
65 keys->enckeylen = be32_to_cpu(param->enckeylen);
66
67 key += RTA_ALIGN(rta->rta_len);
68 keylen -= RTA_ALIGN(rta->rta_len);
69
70 if (keylen < keys->enckeylen)
71 return -EINVAL;
72
73 keys->authkeylen = keylen - keys->enckeylen;
74 keys->authkey = key;
75 keys->enckey = key + keys->authkeylen;
76
77 return 0;
78}
79EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
80
81static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
82 unsigned int keylen)
83{
84 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
85 struct crypto_ahash *auth = ctx->auth;
86 struct crypto_ablkcipher *enc = ctx->enc;
87 struct crypto_authenc_keys keys;
88 int err = -EINVAL;
89
90 if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
91 goto badkey;
92
93 crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
94 crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
95 CRYPTO_TFM_REQ_MASK);
96 err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
97 crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
98 CRYPTO_TFM_RES_MASK);
99
100 if (err)
101 goto out;
102
103 crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
104 crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
105 CRYPTO_TFM_REQ_MASK);
106 err = crypto_ablkcipher_setkey(enc, keys.enckey, keys.enckeylen);
107 crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
108 CRYPTO_TFM_RES_MASK);
109
110out:
111 return err;
112
113badkey:
114 crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
115 goto out;
116}
117
118static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
119{
120 struct aead_request *req = areq->data;
121 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
122 struct aead_instance *inst = aead_alg_instance(authenc);
123 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
124 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
125 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
126
127 if (err)
128 goto out;
129
130 scatterwalk_map_and_copy(ahreq->result, req->dst,
131 req->assoclen + req->cryptlen,
132 crypto_aead_authsize(authenc), 1);
133
134out:
135 aead_request_complete(req, err);
136}
137
138static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
139{
140 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
141 struct aead_instance *inst = aead_alg_instance(authenc);
142 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
143 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
144 struct crypto_ahash *auth = ctx->auth;
145 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
146 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
147 u8 *hash = areq_ctx->tail;
148 int err;
149
150 hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
151 crypto_ahash_alignmask(auth) + 1);
152
153 ahash_request_set_tfm(ahreq, auth);
154 ahash_request_set_crypt(ahreq, req->dst, hash,
155 req->assoclen + req->cryptlen);
156 ahash_request_set_callback(ahreq, flags,
157 authenc_geniv_ahash_done, req);
158
159 err = crypto_ahash_digest(ahreq);
160 if (err)
161 return err;
162
163 scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,
164 crypto_aead_authsize(authenc), 1);
165
166 return 0;
167}
168
169static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
170 int err)
171{
172 struct aead_request *areq = req->data;
173
174 if (err)
175 goto out;
176
177 err = crypto_authenc_genicv(areq, 0);
178
179out:
180 authenc_request_complete(areq, err);
181}
182
183static int crypto_authenc_copy_assoc(struct aead_request *req)
184{
185 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
186 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
187 struct blkcipher_desc desc = {
188 .tfm = ctx->null,
189 };
190
191 return crypto_blkcipher_encrypt(&desc, req->dst, req->src,
192 req->assoclen);
193}
194
195static int crypto_authenc_encrypt(struct aead_request *req)
196{
197 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
198 struct aead_instance *inst = aead_alg_instance(authenc);
199 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
200 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
201 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
202 struct crypto_ablkcipher *enc = ctx->enc;
203 unsigned int cryptlen = req->cryptlen;
204 struct ablkcipher_request *abreq = (void *)(areq_ctx->tail +
205 ictx->reqoff);
206 struct scatterlist *src, *dst;
207 int err;
208
209 sg_init_table(areq_ctx->src, 2);
210 src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
211 dst = src;
212
213 if (req->src != req->dst) {
214 err = crypto_authenc_copy_assoc(req);
215 if (err)
216 return err;
217
218 sg_init_table(areq_ctx->dst, 2);
219 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
220 }
221
222 ablkcipher_request_set_tfm(abreq, enc);
223 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
224 crypto_authenc_encrypt_done, req);
225 ablkcipher_request_set_crypt(abreq, src, dst, cryptlen, req->iv);
226
227 err = crypto_ablkcipher_encrypt(abreq);
228 if (err)
229 return err;
230
231 return crypto_authenc_genicv(req, aead_request_flags(req));
232}
233
234static int crypto_authenc_decrypt_tail(struct aead_request *req,
235 unsigned int flags)
236{
237 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
238 struct aead_instance *inst = aead_alg_instance(authenc);
239 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
240 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
241 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
242 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
243 struct ablkcipher_request *abreq = (void *)(areq_ctx->tail +
244 ictx->reqoff);
245 unsigned int authsize = crypto_aead_authsize(authenc);
246 u8 *ihash = ahreq->result + authsize;
247 struct scatterlist *src, *dst;
248
249 scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0);
250
251 if (crypto_memneq(ihash, ahreq->result, authsize))
252 return -EBADMSG;
253
254 sg_init_table(areq_ctx->src, 2);
255 src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
256 dst = src;
257
258 if (req->src != req->dst) {
259 sg_init_table(areq_ctx->dst, 2);
260 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
261 }
262
263 ablkcipher_request_set_tfm(abreq, ctx->enc);
264 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
265 req->base.complete, req->base.data);
266 ablkcipher_request_set_crypt(abreq, src, dst,
267 req->cryptlen - authsize, req->iv);
268
269 return crypto_ablkcipher_decrypt(abreq);
270}
271
272static void authenc_verify_ahash_done(struct crypto_async_request *areq,
273 int err)
274{
275 struct aead_request *req = areq->data;
276
277 if (err)
278 goto out;
279
280 err = crypto_authenc_decrypt_tail(req, 0);
281
282out:
283 authenc_request_complete(req, err);
284}
285
286static int crypto_authenc_decrypt(struct aead_request *req)
287{
288 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
289 unsigned int authsize = crypto_aead_authsize(authenc);
290 struct aead_instance *inst = aead_alg_instance(authenc);
291 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
292 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
293 struct crypto_ahash *auth = ctx->auth;
294 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
295 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
296 u8 *hash = areq_ctx->tail;
297 int err;
298
299 hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
300 crypto_ahash_alignmask(auth) + 1);
301
302 ahash_request_set_tfm(ahreq, auth);
303 ahash_request_set_crypt(ahreq, req->src, hash,
304 req->assoclen + req->cryptlen - authsize);
305 ahash_request_set_callback(ahreq, aead_request_flags(req),
306 authenc_verify_ahash_done, req);
307
308 err = crypto_ahash_digest(ahreq);
309 if (err)
310 return err;
311
312 return crypto_authenc_decrypt_tail(req, aead_request_flags(req));
313}
314
315static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
316{
317 struct aead_instance *inst = aead_alg_instance(tfm);
318 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
319 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
320 struct crypto_ahash *auth;
321 struct crypto_ablkcipher *enc;
322 struct crypto_blkcipher *null;
323 int err;
324
325 auth = crypto_spawn_ahash(&ictx->auth);
326 if (IS_ERR(auth))
327 return PTR_ERR(auth);
328
329 enc = crypto_spawn_skcipher(&ictx->enc);
330 err = PTR_ERR(enc);
331 if (IS_ERR(enc))
332 goto err_free_ahash;
333
334 null = crypto_get_default_null_skcipher();
335 err = PTR_ERR(null);
336 if (IS_ERR(null))
337 goto err_free_skcipher;
338
339 ctx->auth = auth;
340 ctx->enc = enc;
341 ctx->null = null;
342
343 crypto_aead_set_reqsize(
344 tfm,
345 sizeof(struct authenc_request_ctx) +
346 ictx->reqoff +
347 max_t(unsigned int,
348 crypto_ahash_reqsize(auth) +
349 sizeof(struct ahash_request),
350 sizeof(struct ablkcipher_request) +
351 crypto_ablkcipher_reqsize(enc)));
352
353 return 0;
354
355err_free_skcipher:
356 crypto_free_ablkcipher(enc);
357err_free_ahash:
358 crypto_free_ahash(auth);
359 return err;
360}
361
362static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
363{
364 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
365
366 crypto_free_ahash(ctx->auth);
367 crypto_free_ablkcipher(ctx->enc);
368 crypto_put_default_null_skcipher();
369}
370
371static void crypto_authenc_free(struct aead_instance *inst)
372{
373 struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);
374
375 crypto_drop_skcipher(&ctx->enc);
376 crypto_drop_ahash(&ctx->auth);
377 kfree(inst);
378}
379
380static int crypto_authenc_create(struct crypto_template *tmpl,
381 struct rtattr **tb)
382{
383 struct crypto_attr_type *algt;
384 struct aead_instance *inst;
385 struct hash_alg_common *auth;
386 struct crypto_alg *auth_base;
387 struct crypto_alg *enc;
388 struct authenc_instance_ctx *ctx;
389 const char *enc_name;
390 int err;
391
392 algt = crypto_get_attr_type(tb);
393 if (IS_ERR(algt))
394 return PTR_ERR(algt);
395
396 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
397 return -EINVAL;
398
399 auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
400 CRYPTO_ALG_TYPE_AHASH_MASK);
401 if (IS_ERR(auth))
402 return PTR_ERR(auth);
403
404 auth_base = &auth->base;
405
406 enc_name = crypto_attr_alg_name(tb[2]);
407 err = PTR_ERR(enc_name);
408 if (IS_ERR(enc_name))
409 goto out_put_auth;
410
411 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
412 err = -ENOMEM;
413 if (!inst)
414 goto out_put_auth;
415
416 ctx = aead_instance_ctx(inst);
417
418 err = crypto_init_ahash_spawn(&ctx->auth, auth,
419 aead_crypto_instance(inst));
420 if (err)
421 goto err_free_inst;
422
423 crypto_set_skcipher_spawn(&ctx->enc, aead_crypto_instance(inst));
424 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
425 crypto_requires_sync(algt->type,
426 algt->mask));
427 if (err)
428 goto err_drop_auth;
429
430 enc = crypto_skcipher_spawn_alg(&ctx->enc);
431
432 ctx->reqoff = ALIGN(2 * auth->digestsize + auth_base->cra_alignmask,
433 auth_base->cra_alignmask + 1);
434
435 err = -ENAMETOOLONG;
436 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
437 "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
438 CRYPTO_MAX_ALG_NAME)
439 goto err_drop_enc;
440
441 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
442 "authenc(%s,%s)", auth_base->cra_driver_name,
443 enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
444 goto err_drop_enc;
445
446 inst->alg.base.cra_flags = enc->cra_flags & CRYPTO_ALG_ASYNC;
447 inst->alg.base.cra_priority = enc->cra_priority * 10 +
448 auth_base->cra_priority;
449 inst->alg.base.cra_blocksize = enc->cra_blocksize;
450 inst->alg.base.cra_alignmask = auth_base->cra_alignmask |
451 enc->cra_alignmask;
452 inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
453
454 inst->alg.ivsize = enc->cra_ablkcipher.ivsize;
455 inst->alg.maxauthsize = auth->digestsize;
456
457 inst->alg.init = crypto_authenc_init_tfm;
458 inst->alg.exit = crypto_authenc_exit_tfm;
459
460 inst->alg.setkey = crypto_authenc_setkey;
461 inst->alg.encrypt = crypto_authenc_encrypt;
462 inst->alg.decrypt = crypto_authenc_decrypt;
463
464 inst->free = crypto_authenc_free;
465
466 err = aead_register_instance(tmpl, inst);
467 if (err)
468 goto err_drop_enc;
469
470out:
471 crypto_mod_put(auth_base);
472 return err;
473
474err_drop_enc:
475 crypto_drop_skcipher(&ctx->enc);
476err_drop_auth:
477 crypto_drop_ahash(&ctx->auth);
478err_free_inst:
479 kfree(inst);
480out_put_auth:
481 goto out;
482}
483
484static struct crypto_template crypto_authenc_tmpl = {
485 .name = "authenc",
486 .create = crypto_authenc_create,
487 .module = THIS_MODULE,
488};
489
490static int __init crypto_authenc_module_init(void)
491{
492 return crypto_register_template(&crypto_authenc_tmpl);
493}
494
495static void __exit crypto_authenc_module_exit(void)
496{
497 crypto_unregister_template(&crypto_authenc_tmpl);
498}
499
500module_init(crypto_authenc_module_init);
501module_exit(crypto_authenc_module_exit);
502
503MODULE_LICENSE("GPL");
504MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
505MODULE_ALIAS_CRYPTO("authenc");