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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Authenc: Simple AEAD wrapper for IPsec
4 *
5 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
8#include <crypto/internal/aead.h>
9#include <crypto/internal/hash.h>
10#include <crypto/internal/skcipher.h>
11#include <crypto/authenc.h>
12#include <crypto/null.h>
13#include <crypto/scatterwalk.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/rtnetlink.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21
22struct authenc_instance_ctx {
23 struct crypto_ahash_spawn auth;
24 struct crypto_skcipher_spawn enc;
25 unsigned int reqoff;
26};
27
28struct crypto_authenc_ctx {
29 struct crypto_ahash *auth;
30 struct crypto_skcipher *enc;
31 struct crypto_sync_skcipher *null;
32};
33
34struct authenc_request_ctx {
35 struct scatterlist src[2];
36 struct scatterlist dst[2];
37 char tail[];
38};
39
40static void authenc_request_complete(struct aead_request *req, int err)
41{
42 if (err != -EINPROGRESS)
43 aead_request_complete(req, err);
44}
45
46int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
47 unsigned int keylen)
48{
49 struct rtattr *rta = (struct rtattr *)key;
50 struct crypto_authenc_key_param *param;
51
52 if (!RTA_OK(rta, keylen))
53 return -EINVAL;
54 if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
55 return -EINVAL;
56
57 /*
58 * RTA_OK() didn't align the rtattr's payload when validating that it
59 * fits in the buffer. Yet, the keys should start on the next 4-byte
60 * aligned boundary. To avoid confusion, require that the rtattr
61 * payload be exactly the param struct, which has a 4-byte aligned size.
62 */
63 if (RTA_PAYLOAD(rta) != sizeof(*param))
64 return -EINVAL;
65 BUILD_BUG_ON(sizeof(*param) % RTA_ALIGNTO);
66
67 param = RTA_DATA(rta);
68 keys->enckeylen = be32_to_cpu(param->enckeylen);
69
70 key += rta->rta_len;
71 keylen -= rta->rta_len;
72
73 if (keylen < keys->enckeylen)
74 return -EINVAL;
75
76 keys->authkeylen = keylen - keys->enckeylen;
77 keys->authkey = key;
78 keys->enckey = key + keys->authkeylen;
79
80 return 0;
81}
82EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
83
84static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
85 unsigned int keylen)
86{
87 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
88 struct crypto_ahash *auth = ctx->auth;
89 struct crypto_skcipher *enc = ctx->enc;
90 struct crypto_authenc_keys keys;
91 int err = -EINVAL;
92
93 if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
94 goto badkey;
95
96 crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
97 crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
98 CRYPTO_TFM_REQ_MASK);
99 err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
100 crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
101 CRYPTO_TFM_RES_MASK);
102
103 if (err)
104 goto out;
105
106 crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
107 crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
108 CRYPTO_TFM_REQ_MASK);
109 err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
110 crypto_aead_set_flags(authenc, crypto_skcipher_get_flags(enc) &
111 CRYPTO_TFM_RES_MASK);
112
113out:
114 memzero_explicit(&keys, sizeof(keys));
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_done(struct crypto_async_request *areq, int err)
123{
124 struct aead_request *req = areq->data;
125 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
126 struct aead_instance *inst = aead_alg_instance(authenc);
127 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
128 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
129 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
130
131 if (err)
132 goto out;
133
134 scatterwalk_map_and_copy(ahreq->result, req->dst,
135 req->assoclen + req->cryptlen,
136 crypto_aead_authsize(authenc), 1);
137
138out:
139 aead_request_complete(req, err);
140}
141
142static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
143{
144 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
145 struct aead_instance *inst = aead_alg_instance(authenc);
146 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
147 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
148 struct crypto_ahash *auth = ctx->auth;
149 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
150 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
151 u8 *hash = areq_ctx->tail;
152 int err;
153
154 hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
155 crypto_ahash_alignmask(auth) + 1);
156
157 ahash_request_set_tfm(ahreq, auth);
158 ahash_request_set_crypt(ahreq, req->dst, hash,
159 req->assoclen + req->cryptlen);
160 ahash_request_set_callback(ahreq, flags,
161 authenc_geniv_ahash_done, req);
162
163 err = crypto_ahash_digest(ahreq);
164 if (err)
165 return err;
166
167 scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,
168 crypto_aead_authsize(authenc), 1);
169
170 return 0;
171}
172
173static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
174 int err)
175{
176 struct aead_request *areq = req->data;
177
178 if (err)
179 goto out;
180
181 err = crypto_authenc_genicv(areq, 0);
182
183out:
184 authenc_request_complete(areq, err);
185}
186
187static int crypto_authenc_copy_assoc(struct aead_request *req)
188{
189 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
190 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
191 SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
192
193 skcipher_request_set_sync_tfm(skreq, ctx->null);
194 skcipher_request_set_callback(skreq, aead_request_flags(req),
195 NULL, NULL);
196 skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen,
197 NULL);
198
199 return crypto_skcipher_encrypt(skreq);
200}
201
202static int crypto_authenc_encrypt(struct aead_request *req)
203{
204 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
205 struct aead_instance *inst = aead_alg_instance(authenc);
206 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
207 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
208 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
209 struct crypto_skcipher *enc = ctx->enc;
210 unsigned int cryptlen = req->cryptlen;
211 struct skcipher_request *skreq = (void *)(areq_ctx->tail +
212 ictx->reqoff);
213 struct scatterlist *src, *dst;
214 int err;
215
216 src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
217 dst = src;
218
219 if (req->src != req->dst) {
220 err = crypto_authenc_copy_assoc(req);
221 if (err)
222 return err;
223
224 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
225 }
226
227 skcipher_request_set_tfm(skreq, enc);
228 skcipher_request_set_callback(skreq, aead_request_flags(req),
229 crypto_authenc_encrypt_done, req);
230 skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
231
232 err = crypto_skcipher_encrypt(skreq);
233 if (err)
234 return err;
235
236 return crypto_authenc_genicv(req, aead_request_flags(req));
237}
238
239static int crypto_authenc_decrypt_tail(struct aead_request *req,
240 unsigned int flags)
241{
242 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
243 struct aead_instance *inst = aead_alg_instance(authenc);
244 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
245 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
246 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
247 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
248 struct skcipher_request *skreq = (void *)(areq_ctx->tail +
249 ictx->reqoff);
250 unsigned int authsize = crypto_aead_authsize(authenc);
251 u8 *ihash = ahreq->result + authsize;
252 struct scatterlist *src, *dst;
253
254 scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0);
255
256 if (crypto_memneq(ihash, ahreq->result, authsize))
257 return -EBADMSG;
258
259 src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
260 dst = src;
261
262 if (req->src != req->dst)
263 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
264
265 skcipher_request_set_tfm(skreq, ctx->enc);
266 skcipher_request_set_callback(skreq, aead_request_flags(req),
267 req->base.complete, req->base.data);
268 skcipher_request_set_crypt(skreq, src, dst,
269 req->cryptlen - authsize, req->iv);
270
271 return crypto_skcipher_decrypt(skreq);
272}
273
274static void authenc_verify_ahash_done(struct crypto_async_request *areq,
275 int err)
276{
277 struct aead_request *req = areq->data;
278
279 if (err)
280 goto out;
281
282 err = crypto_authenc_decrypt_tail(req, 0);
283
284out:
285 authenc_request_complete(req, err);
286}
287
288static int crypto_authenc_decrypt(struct aead_request *req)
289{
290 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
291 unsigned int authsize = crypto_aead_authsize(authenc);
292 struct aead_instance *inst = aead_alg_instance(authenc);
293 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
294 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
295 struct crypto_ahash *auth = ctx->auth;
296 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
297 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
298 u8 *hash = areq_ctx->tail;
299 int err;
300
301 hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
302 crypto_ahash_alignmask(auth) + 1);
303
304 ahash_request_set_tfm(ahreq, auth);
305 ahash_request_set_crypt(ahreq, req->src, hash,
306 req->assoclen + req->cryptlen - authsize);
307 ahash_request_set_callback(ahreq, aead_request_flags(req),
308 authenc_verify_ahash_done, req);
309
310 err = crypto_ahash_digest(ahreq);
311 if (err)
312 return err;
313
314 return crypto_authenc_decrypt_tail(req, aead_request_flags(req));
315}
316
317static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
318{
319 struct aead_instance *inst = aead_alg_instance(tfm);
320 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
321 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
322 struct crypto_ahash *auth;
323 struct crypto_skcipher *enc;
324 struct crypto_sync_skcipher *null;
325 int err;
326
327 auth = crypto_spawn_ahash(&ictx->auth);
328 if (IS_ERR(auth))
329 return PTR_ERR(auth);
330
331 enc = crypto_spawn_skcipher(&ictx->enc);
332 err = PTR_ERR(enc);
333 if (IS_ERR(enc))
334 goto err_free_ahash;
335
336 null = crypto_get_default_null_skcipher();
337 err = PTR_ERR(null);
338 if (IS_ERR(null))
339 goto err_free_skcipher;
340
341 ctx->auth = auth;
342 ctx->enc = enc;
343 ctx->null = null;
344
345 crypto_aead_set_reqsize(
346 tfm,
347 sizeof(struct authenc_request_ctx) +
348 ictx->reqoff +
349 max_t(unsigned int,
350 crypto_ahash_reqsize(auth) +
351 sizeof(struct ahash_request),
352 sizeof(struct skcipher_request) +
353 crypto_skcipher_reqsize(enc)));
354
355 return 0;
356
357err_free_skcipher:
358 crypto_free_skcipher(enc);
359err_free_ahash:
360 crypto_free_ahash(auth);
361 return err;
362}
363
364static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
365{
366 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
367
368 crypto_free_ahash(ctx->auth);
369 crypto_free_skcipher(ctx->enc);
370 crypto_put_default_null_skcipher();
371}
372
373static void crypto_authenc_free(struct aead_instance *inst)
374{
375 struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);
376
377 crypto_drop_skcipher(&ctx->enc);
378 crypto_drop_ahash(&ctx->auth);
379 kfree(inst);
380}
381
382static int crypto_authenc_create(struct crypto_template *tmpl,
383 struct rtattr **tb)
384{
385 struct crypto_attr_type *algt;
386 struct aead_instance *inst;
387 struct hash_alg_common *auth;
388 struct crypto_alg *auth_base;
389 struct skcipher_alg *enc;
390 struct authenc_instance_ctx *ctx;
391 const char *enc_name;
392 int err;
393
394 algt = crypto_get_attr_type(tb);
395 if (IS_ERR(algt))
396 return PTR_ERR(algt);
397
398 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
399 return -EINVAL;
400
401 auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
402 CRYPTO_ALG_TYPE_AHASH_MASK |
403 crypto_requires_sync(algt->type, algt->mask));
404 if (IS_ERR(auth))
405 return PTR_ERR(auth);
406
407 auth_base = &auth->base;
408
409 enc_name = crypto_attr_alg_name(tb[2]);
410 err = PTR_ERR(enc_name);
411 if (IS_ERR(enc_name))
412 goto out_put_auth;
413
414 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
415 err = -ENOMEM;
416 if (!inst)
417 goto out_put_auth;
418
419 ctx = aead_instance_ctx(inst);
420
421 err = crypto_init_ahash_spawn(&ctx->auth, auth,
422 aead_crypto_instance(inst));
423 if (err)
424 goto err_free_inst;
425
426 crypto_set_skcipher_spawn(&ctx->enc, aead_crypto_instance(inst));
427 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
428 crypto_requires_sync(algt->type,
429 algt->mask));
430 if (err)
431 goto err_drop_auth;
432
433 enc = crypto_spawn_skcipher_alg(&ctx->enc);
434
435 ctx->reqoff = ALIGN(2 * auth->digestsize + auth_base->cra_alignmask,
436 auth_base->cra_alignmask + 1);
437
438 err = -ENAMETOOLONG;
439 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
440 "authenc(%s,%s)", auth_base->cra_name,
441 enc->base.cra_name) >=
442 CRYPTO_MAX_ALG_NAME)
443 goto err_drop_enc;
444
445 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
446 "authenc(%s,%s)", auth_base->cra_driver_name,
447 enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
448 goto err_drop_enc;
449
450 inst->alg.base.cra_flags = (auth_base->cra_flags |
451 enc->base.cra_flags) & CRYPTO_ALG_ASYNC;
452 inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
453 auth_base->cra_priority;
454 inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
455 inst->alg.base.cra_alignmask = auth_base->cra_alignmask |
456 enc->base.cra_alignmask;
457 inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
458
459 inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc);
460 inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc);
461 inst->alg.maxauthsize = auth->digestsize;
462
463 inst->alg.init = crypto_authenc_init_tfm;
464 inst->alg.exit = crypto_authenc_exit_tfm;
465
466 inst->alg.setkey = crypto_authenc_setkey;
467 inst->alg.encrypt = crypto_authenc_encrypt;
468 inst->alg.decrypt = crypto_authenc_decrypt;
469
470 inst->free = crypto_authenc_free;
471
472 err = aead_register_instance(tmpl, inst);
473 if (err)
474 goto err_drop_enc;
475
476out:
477 crypto_mod_put(auth_base);
478 return err;
479
480err_drop_enc:
481 crypto_drop_skcipher(&ctx->enc);
482err_drop_auth:
483 crypto_drop_ahash(&ctx->auth);
484err_free_inst:
485 kfree(inst);
486out_put_auth:
487 goto out;
488}
489
490static struct crypto_template crypto_authenc_tmpl = {
491 .name = "authenc",
492 .create = crypto_authenc_create,
493 .module = THIS_MODULE,
494};
495
496static int __init crypto_authenc_module_init(void)
497{
498 return crypto_register_template(&crypto_authenc_tmpl);
499}
500
501static void __exit crypto_authenc_module_exit(void)
502{
503 crypto_unregister_template(&crypto_authenc_tmpl);
504}
505
506subsys_initcall(crypto_authenc_module_init);
507module_exit(crypto_authenc_module_exit);
508
509MODULE_LICENSE("GPL");
510MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
511MODULE_ALIAS_CRYPTO("authenc");