xref: /openbmc/linux/crypto/authenc.c (revision 95e9fd10)
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 static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
56 				 unsigned int keylen)
57 {
58 	unsigned int authkeylen;
59 	unsigned int enckeylen;
60 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
61 	struct crypto_ahash *auth = ctx->auth;
62 	struct crypto_ablkcipher *enc = ctx->enc;
63 	struct rtattr *rta = (void *)key;
64 	struct crypto_authenc_key_param *param;
65 	int err = -EINVAL;
66 
67 	if (!RTA_OK(rta, keylen))
68 		goto badkey;
69 	if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
70 		goto badkey;
71 	if (RTA_PAYLOAD(rta) < sizeof(*param))
72 		goto badkey;
73 
74 	param = RTA_DATA(rta);
75 	enckeylen = be32_to_cpu(param->enckeylen);
76 
77 	key += RTA_ALIGN(rta->rta_len);
78 	keylen -= RTA_ALIGN(rta->rta_len);
79 
80 	if (keylen < enckeylen)
81 		goto badkey;
82 
83 	authkeylen = keylen - enckeylen;
84 
85 	crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
86 	crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
87 				    CRYPTO_TFM_REQ_MASK);
88 	err = crypto_ahash_setkey(auth, key, authkeylen);
89 	crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
90 				       CRYPTO_TFM_RES_MASK);
91 
92 	if (err)
93 		goto out;
94 
95 	crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
96 	crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
97 					 CRYPTO_TFM_REQ_MASK);
98 	err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
99 	crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
100 				       CRYPTO_TFM_RES_MASK);
101 
102 out:
103 	return err;
104 
105 badkey:
106 	crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
107 	goto out;
108 }
109 
110 static void authenc_geniv_ahash_update_done(struct crypto_async_request *areq,
111 					    int err)
112 {
113 	struct aead_request *req = areq->data;
114 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
115 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
116 	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
117 	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
118 
119 	if (err)
120 		goto out;
121 
122 	ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
123 				areq_ctx->cryptlen);
124 	ahash_request_set_callback(ahreq, aead_request_flags(req) &
125 					  CRYPTO_TFM_REQ_MAY_SLEEP,
126 				   areq_ctx->complete, req);
127 
128 	err = crypto_ahash_finup(ahreq);
129 	if (err)
130 		goto out;
131 
132 	scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
133 				 areq_ctx->cryptlen,
134 				 crypto_aead_authsize(authenc), 1);
135 
136 out:
137 	authenc_request_complete(req, err);
138 }
139 
140 static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
141 {
142 	struct aead_request *req = areq->data;
143 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
144 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
145 	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
146 	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
147 
148 	if (err)
149 		goto out;
150 
151 	scatterwalk_map_and_copy(ahreq->result, areq_ctx->sg,
152 				 areq_ctx->cryptlen,
153 				 crypto_aead_authsize(authenc), 1);
154 
155 out:
156 	aead_request_complete(req, err);
157 }
158 
159 static void authenc_verify_ahash_update_done(struct crypto_async_request *areq,
160 					     int err)
161 {
162 	u8 *ihash;
163 	unsigned int authsize;
164 	struct ablkcipher_request *abreq;
165 	struct aead_request *req = areq->data;
166 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
167 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
168 	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
169 	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
170 	unsigned int cryptlen = req->cryptlen;
171 
172 	if (err)
173 		goto out;
174 
175 	ahash_request_set_crypt(ahreq, areq_ctx->sg, ahreq->result,
176 				areq_ctx->cryptlen);
177 	ahash_request_set_callback(ahreq, aead_request_flags(req) &
178 					  CRYPTO_TFM_REQ_MAY_SLEEP,
179 				   areq_ctx->complete, req);
180 
181 	err = crypto_ahash_finup(ahreq);
182 	if (err)
183 		goto out;
184 
185 	authsize = crypto_aead_authsize(authenc);
186 	cryptlen -= authsize;
187 	ihash = ahreq->result + authsize;
188 	scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
189 				 authsize, 0);
190 
191 	err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
192 	if (err)
193 		goto out;
194 
195 	abreq = aead_request_ctx(req);
196 	ablkcipher_request_set_tfm(abreq, ctx->enc);
197 	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
198 					req->base.complete, req->base.data);
199 	ablkcipher_request_set_crypt(abreq, req->src, req->dst,
200 				     cryptlen, req->iv);
201 
202 	err = crypto_ablkcipher_decrypt(abreq);
203 
204 out:
205 	authenc_request_complete(req, err);
206 }
207 
208 static void authenc_verify_ahash_done(struct crypto_async_request *areq,
209 				      int err)
210 {
211 	u8 *ihash;
212 	unsigned int authsize;
213 	struct ablkcipher_request *abreq;
214 	struct aead_request *req = areq->data;
215 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
216 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
217 	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
218 	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
219 	unsigned int cryptlen = req->cryptlen;
220 
221 	if (err)
222 		goto out;
223 
224 	authsize = crypto_aead_authsize(authenc);
225 	cryptlen -= authsize;
226 	ihash = ahreq->result + authsize;
227 	scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
228 				 authsize, 0);
229 
230 	err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0;
231 	if (err)
232 		goto out;
233 
234 	abreq = aead_request_ctx(req);
235 	ablkcipher_request_set_tfm(abreq, ctx->enc);
236 	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
237 					req->base.complete, req->base.data);
238 	ablkcipher_request_set_crypt(abreq, req->src, req->dst,
239 				     cryptlen, req->iv);
240 
241 	err = crypto_ablkcipher_decrypt(abreq);
242 
243 out:
244 	authenc_request_complete(req, err);
245 }
246 
247 static u8 *crypto_authenc_ahash_fb(struct aead_request *req, unsigned int flags)
248 {
249 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
250 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
251 	struct crypto_ahash *auth = ctx->auth;
252 	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
253 	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
254 	u8 *hash = areq_ctx->tail;
255 	int err;
256 
257 	hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
258 			    crypto_ahash_alignmask(auth) + 1);
259 
260 	ahash_request_set_tfm(ahreq, auth);
261 
262 	err = crypto_ahash_init(ahreq);
263 	if (err)
264 		return ERR_PTR(err);
265 
266 	ahash_request_set_crypt(ahreq, req->assoc, hash, req->assoclen);
267 	ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
268 				   areq_ctx->update_complete, req);
269 
270 	err = crypto_ahash_update(ahreq);
271 	if (err)
272 		return ERR_PTR(err);
273 
274 	ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
275 				areq_ctx->cryptlen);
276 	ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
277 				   areq_ctx->complete, req);
278 
279 	err = crypto_ahash_finup(ahreq);
280 	if (err)
281 		return ERR_PTR(err);
282 
283 	return hash;
284 }
285 
286 static u8 *crypto_authenc_ahash(struct aead_request *req, unsigned int flags)
287 {
288 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
289 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
290 	struct crypto_ahash *auth = ctx->auth;
291 	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
292 	struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
293 	u8 *hash = areq_ctx->tail;
294 	int err;
295 
296 	hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
297 			   crypto_ahash_alignmask(auth) + 1);
298 
299 	ahash_request_set_tfm(ahreq, auth);
300 	ahash_request_set_crypt(ahreq, areq_ctx->sg, hash,
301 				areq_ctx->cryptlen);
302 	ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
303 				   areq_ctx->complete, req);
304 
305 	err = crypto_ahash_digest(ahreq);
306 	if (err)
307 		return ERR_PTR(err);
308 
309 	return hash;
310 }
311 
312 static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
313 				 unsigned int flags)
314 {
315 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
316 	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
317 	struct scatterlist *dst = req->dst;
318 	struct scatterlist *assoc = req->assoc;
319 	struct scatterlist *cipher = areq_ctx->cipher;
320 	struct scatterlist *asg = areq_ctx->asg;
321 	unsigned int ivsize = crypto_aead_ivsize(authenc);
322 	unsigned int cryptlen = req->cryptlen;
323 	authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
324 	struct page *dstp;
325 	u8 *vdst;
326 	u8 *hash;
327 
328 	dstp = sg_page(dst);
329 	vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
330 
331 	if (ivsize) {
332 		sg_init_table(cipher, 2);
333 		sg_set_buf(cipher, iv, ivsize);
334 		scatterwalk_crypto_chain(cipher, dst, vdst == iv + ivsize, 2);
335 		dst = cipher;
336 		cryptlen += ivsize;
337 	}
338 
339 	if (sg_is_last(assoc)) {
340 		authenc_ahash_fn = crypto_authenc_ahash;
341 		sg_init_table(asg, 2);
342 		sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
343 		scatterwalk_crypto_chain(asg, dst, 0, 2);
344 		dst = asg;
345 		cryptlen += req->assoclen;
346 	}
347 
348 	areq_ctx->cryptlen = cryptlen;
349 	areq_ctx->sg = dst;
350 
351 	areq_ctx->complete = authenc_geniv_ahash_done;
352 	areq_ctx->update_complete = authenc_geniv_ahash_update_done;
353 
354 	hash = authenc_ahash_fn(req, flags);
355 	if (IS_ERR(hash))
356 		return PTR_ERR(hash);
357 
358 	scatterwalk_map_and_copy(hash, dst, cryptlen,
359 				 crypto_aead_authsize(authenc), 1);
360 	return 0;
361 }
362 
363 static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
364 					int err)
365 {
366 	struct aead_request *areq = req->data;
367 
368 	if (!err) {
369 		struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
370 		struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
371 		struct ablkcipher_request *abreq = aead_request_ctx(areq);
372 		u8 *iv = (u8 *)(abreq + 1) +
373 			 crypto_ablkcipher_reqsize(ctx->enc);
374 
375 		err = crypto_authenc_genicv(areq, iv, 0);
376 	}
377 
378 	authenc_request_complete(areq, err);
379 }
380 
381 static int crypto_authenc_encrypt(struct aead_request *req)
382 {
383 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
384 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
385 	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
386 	struct crypto_ablkcipher *enc = ctx->enc;
387 	struct scatterlist *dst = req->dst;
388 	unsigned int cryptlen = req->cryptlen;
389 	struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
390 						    + ctx->reqoff);
391 	u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
392 	int err;
393 
394 	ablkcipher_request_set_tfm(abreq, enc);
395 	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
396 					crypto_authenc_encrypt_done, req);
397 	ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
398 
399 	memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
400 
401 	err = crypto_ablkcipher_encrypt(abreq);
402 	if (err)
403 		return err;
404 
405 	return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
406 }
407 
408 static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
409 					   int err)
410 {
411 	struct aead_request *areq = req->data;
412 
413 	if (!err) {
414 		struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
415 
416 		err = crypto_authenc_genicv(areq, greq->giv, 0);
417 	}
418 
419 	authenc_request_complete(areq, err);
420 }
421 
422 static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
423 {
424 	struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
425 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
426 	struct aead_request *areq = &req->areq;
427 	struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
428 	u8 *iv = req->giv;
429 	int err;
430 
431 	skcipher_givcrypt_set_tfm(greq, ctx->enc);
432 	skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
433 				       crypto_authenc_givencrypt_done, areq);
434 	skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
435 				    areq->iv);
436 	skcipher_givcrypt_set_giv(greq, iv, req->seq);
437 
438 	err = crypto_skcipher_givencrypt(greq);
439 	if (err)
440 		return err;
441 
442 	return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
443 }
444 
445 static int crypto_authenc_verify(struct aead_request *req,
446 				 authenc_ahash_t authenc_ahash_fn)
447 {
448 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
449 	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
450 	u8 *ohash;
451 	u8 *ihash;
452 	unsigned int authsize;
453 
454 	areq_ctx->complete = authenc_verify_ahash_done;
455 	areq_ctx->update_complete = authenc_verify_ahash_update_done;
456 
457 	ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
458 	if (IS_ERR(ohash))
459 		return PTR_ERR(ohash);
460 
461 	authsize = crypto_aead_authsize(authenc);
462 	ihash = ohash + authsize;
463 	scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
464 				 authsize, 0);
465 	return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0;
466 }
467 
468 static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
469 				  unsigned int cryptlen)
470 {
471 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
472 	struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
473 	struct scatterlist *src = req->src;
474 	struct scatterlist *assoc = req->assoc;
475 	struct scatterlist *cipher = areq_ctx->cipher;
476 	struct scatterlist *asg = areq_ctx->asg;
477 	unsigned int ivsize = crypto_aead_ivsize(authenc);
478 	authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
479 	struct page *srcp;
480 	u8 *vsrc;
481 
482 	srcp = sg_page(src);
483 	vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
484 
485 	if (ivsize) {
486 		sg_init_table(cipher, 2);
487 		sg_set_buf(cipher, iv, ivsize);
488 		scatterwalk_crypto_chain(cipher, src, vsrc == iv + ivsize, 2);
489 		src = cipher;
490 		cryptlen += ivsize;
491 	}
492 
493 	if (sg_is_last(assoc)) {
494 		authenc_ahash_fn = crypto_authenc_ahash;
495 		sg_init_table(asg, 2);
496 		sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
497 		scatterwalk_crypto_chain(asg, src, 0, 2);
498 		src = asg;
499 		cryptlen += req->assoclen;
500 	}
501 
502 	areq_ctx->cryptlen = cryptlen;
503 	areq_ctx->sg = src;
504 
505 	return crypto_authenc_verify(req, authenc_ahash_fn);
506 }
507 
508 static int crypto_authenc_decrypt(struct aead_request *req)
509 {
510 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
511 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
512 	struct ablkcipher_request *abreq = aead_request_ctx(req);
513 	unsigned int cryptlen = req->cryptlen;
514 	unsigned int authsize = crypto_aead_authsize(authenc);
515 	u8 *iv = req->iv;
516 	int err;
517 
518 	if (cryptlen < authsize)
519 		return -EINVAL;
520 	cryptlen -= authsize;
521 
522 	err = crypto_authenc_iverify(req, iv, cryptlen);
523 	if (err)
524 		return err;
525 
526 	ablkcipher_request_set_tfm(abreq, ctx->enc);
527 	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
528 					req->base.complete, req->base.data);
529 	ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
530 
531 	return crypto_ablkcipher_decrypt(abreq);
532 }
533 
534 static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
535 {
536 	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
537 	struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
538 	struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
539 	struct crypto_ahash *auth;
540 	struct crypto_ablkcipher *enc;
541 	int err;
542 
543 	auth = crypto_spawn_ahash(&ictx->auth);
544 	if (IS_ERR(auth))
545 		return PTR_ERR(auth);
546 
547 	enc = crypto_spawn_skcipher(&ictx->enc);
548 	err = PTR_ERR(enc);
549 	if (IS_ERR(enc))
550 		goto err_free_ahash;
551 
552 	ctx->auth = auth;
553 	ctx->enc = enc;
554 
555 	ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
556 			    crypto_ahash_alignmask(auth),
557 			    crypto_ahash_alignmask(auth) + 1) +
558 		      crypto_ablkcipher_ivsize(enc);
559 
560 	tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
561 				ctx->reqoff +
562 				max_t(unsigned int,
563 				crypto_ahash_reqsize(auth) +
564 				sizeof(struct ahash_request),
565 				sizeof(struct skcipher_givcrypt_request) +
566 				crypto_ablkcipher_reqsize(enc));
567 
568 	return 0;
569 
570 err_free_ahash:
571 	crypto_free_ahash(auth);
572 	return err;
573 }
574 
575 static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
576 {
577 	struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
578 
579 	crypto_free_ahash(ctx->auth);
580 	crypto_free_ablkcipher(ctx->enc);
581 }
582 
583 static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
584 {
585 	struct crypto_attr_type *algt;
586 	struct crypto_instance *inst;
587 	struct hash_alg_common *auth;
588 	struct crypto_alg *auth_base;
589 	struct crypto_alg *enc;
590 	struct authenc_instance_ctx *ctx;
591 	const char *enc_name;
592 	int err;
593 
594 	algt = crypto_get_attr_type(tb);
595 	err = PTR_ERR(algt);
596 	if (IS_ERR(algt))
597 		return ERR_PTR(err);
598 
599 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
600 		return ERR_PTR(-EINVAL);
601 
602 	auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
603 			       CRYPTO_ALG_TYPE_AHASH_MASK);
604 	if (IS_ERR(auth))
605 		return ERR_CAST(auth);
606 
607 	auth_base = &auth->base;
608 
609 	enc_name = crypto_attr_alg_name(tb[2]);
610 	err = PTR_ERR(enc_name);
611 	if (IS_ERR(enc_name))
612 		goto out_put_auth;
613 
614 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
615 	err = -ENOMEM;
616 	if (!inst)
617 		goto out_put_auth;
618 
619 	ctx = crypto_instance_ctx(inst);
620 
621 	err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
622 	if (err)
623 		goto err_free_inst;
624 
625 	crypto_set_skcipher_spawn(&ctx->enc, inst);
626 	err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
627 				   crypto_requires_sync(algt->type,
628 							algt->mask));
629 	if (err)
630 		goto err_drop_auth;
631 
632 	enc = crypto_skcipher_spawn_alg(&ctx->enc);
633 
634 	err = -ENAMETOOLONG;
635 	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
636 		     "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
637 	    CRYPTO_MAX_ALG_NAME)
638 		goto err_drop_enc;
639 
640 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
641 		     "authenc(%s,%s)", auth_base->cra_driver_name,
642 		     enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
643 		goto err_drop_enc;
644 
645 	inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
646 	inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
647 	inst->alg.cra_priority = enc->cra_priority *
648 				 10 + auth_base->cra_priority;
649 	inst->alg.cra_blocksize = enc->cra_blocksize;
650 	inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
651 	inst->alg.cra_type = &crypto_aead_type;
652 
653 	inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
654 	inst->alg.cra_aead.maxauthsize = auth->digestsize;
655 
656 	inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
657 
658 	inst->alg.cra_init = crypto_authenc_init_tfm;
659 	inst->alg.cra_exit = crypto_authenc_exit_tfm;
660 
661 	inst->alg.cra_aead.setkey = crypto_authenc_setkey;
662 	inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
663 	inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
664 	inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
665 
666 out:
667 	crypto_mod_put(auth_base);
668 	return inst;
669 
670 err_drop_enc:
671 	crypto_drop_skcipher(&ctx->enc);
672 err_drop_auth:
673 	crypto_drop_ahash(&ctx->auth);
674 err_free_inst:
675 	kfree(inst);
676 out_put_auth:
677 	inst = ERR_PTR(err);
678 	goto out;
679 }
680 
681 static void crypto_authenc_free(struct crypto_instance *inst)
682 {
683 	struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
684 
685 	crypto_drop_skcipher(&ctx->enc);
686 	crypto_drop_ahash(&ctx->auth);
687 	kfree(inst);
688 }
689 
690 static struct crypto_template crypto_authenc_tmpl = {
691 	.name = "authenc",
692 	.alloc = crypto_authenc_alloc,
693 	.free = crypto_authenc_free,
694 	.module = THIS_MODULE,
695 };
696 
697 static int __init crypto_authenc_module_init(void)
698 {
699 	return crypto_register_template(&crypto_authenc_tmpl);
700 }
701 
702 static void __exit crypto_authenc_module_exit(void)
703 {
704 	crypto_unregister_template(&crypto_authenc_tmpl);
705 }
706 
707 module_init(crypto_authenc_module_init);
708 module_exit(crypto_authenc_module_exit);
709 
710 MODULE_LICENSE("GPL");
711 MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
712