xref: /linux/crypto/authenc.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
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 
26 typedef u8 *(*authenc_ahash_t)(struct aead_request *req, unsigned int flags);
27 
28 struct authenc_instance_ctx {
29 	struct crypto_ahash_spawn auth;
30 	struct crypto_skcipher_spawn enc;
31 };
32 
33 struct crypto_authenc_ctx {
34 	unsigned int reqoff;
35 	struct crypto_ahash *auth;
36 	struct crypto_ablkcipher *enc;
37 };
38 
39 struct 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 
49 static void authenc_request_complete(struct aead_request *req, int err)
50 {
51 	if (err != -EINPROGRESS)
52 		aead_request_complete(req, err);
53 }
54 
55 int 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 }
83 EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
84 
85 static 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 
114 out:
115 	return err;
116 
117 badkey:
118 	crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
119 	goto out;
120 }
121 
122 static 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 
148 out:
149 	authenc_request_complete(req, err);
150 }
151 
152 static 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 
167 out:
168 	aead_request_complete(req, err);
169 }
170 
171 static 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 
216 out:
217 	authenc_request_complete(req, err);
218 }
219 
220 static 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 
255 out:
256 	authenc_request_complete(req, err);
257 }
258 
259 static 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 
298 static 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 
324 static 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 
375 static 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 
394 static 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 
421 static 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 
435 static 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 
458 static 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 
481 static 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 
521 static 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 
547 static 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 
583 err_free_ahash:
584 	crypto_free_ahash(auth);
585 	return err;
586 }
587 
588 static 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 
596 static 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 
678 out:
679 	crypto_mod_put(auth_base);
680 	return inst;
681 
682 err_drop_enc:
683 	crypto_drop_skcipher(&ctx->enc);
684 err_drop_auth:
685 	crypto_drop_ahash(&ctx->auth);
686 err_free_inst:
687 	kfree(inst);
688 out_put_auth:
689 	inst = ERR_PTR(err);
690 	goto out;
691 }
692 
693 static 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 
702 static 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 
709 static int __init crypto_authenc_module_init(void)
710 {
711 	return crypto_register_template(&crypto_authenc_tmpl);
712 }
713 
714 static void __exit crypto_authenc_module_exit(void)
715 {
716 	crypto_unregister_template(&crypto_authenc_tmpl);
717 }
718 
719 module_init(crypto_authenc_module_init);
720 module_exit(crypto_authenc_module_exit);
721 
722 MODULE_LICENSE("GPL");
723 MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
724 MODULE_ALIAS_CRYPTO("authenc");
725