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
authenc_request_complete(struct aead_request * req,int err)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
crypto_authenc_setkey(struct crypto_aead * authenc,const u8 * key,unsigned int keylen)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
authenc_geniv_ahash_update_done(struct crypto_async_request * areq,int err)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
authenc_geniv_ahash_done(struct crypto_async_request * areq,int err)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
authenc_verify_ahash_update_done(struct crypto_async_request * areq,int err)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
authenc_verify_ahash_done(struct crypto_async_request * areq,int err)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
crypto_authenc_ahash_fb(struct aead_request * req,unsigned int flags)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
crypto_authenc_ahash(struct aead_request * req,unsigned int flags)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
crypto_authenc_genicv(struct aead_request * req,u8 * iv,unsigned int flags)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
crypto_authenc_encrypt_done(struct crypto_async_request * req,int err)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 authenc_request_ctx *areq_ctx = aead_request_ctx(areq);
372 struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
373 + ctx->reqoff);
374 u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(ctx->enc);
375
376 err = crypto_authenc_genicv(areq, iv, 0);
377 }
378
379 authenc_request_complete(areq, err);
380 }
381
crypto_authenc_encrypt(struct aead_request * req)382 static int crypto_authenc_encrypt(struct aead_request *req)
383 {
384 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
385 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
386 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
387 struct crypto_ablkcipher *enc = ctx->enc;
388 struct scatterlist *dst = req->dst;
389 unsigned int cryptlen = req->cryptlen;
390 struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
391 + ctx->reqoff);
392 u8 *iv = (u8 *)abreq - crypto_ablkcipher_ivsize(enc);
393 int err;
394
395 ablkcipher_request_set_tfm(abreq, enc);
396 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
397 crypto_authenc_encrypt_done, req);
398 ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
399
400 memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
401
402 err = crypto_ablkcipher_encrypt(abreq);
403 if (err)
404 return err;
405
406 return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
407 }
408
crypto_authenc_givencrypt_done(struct crypto_async_request * req,int err)409 static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
410 int err)
411 {
412 struct aead_request *areq = req->data;
413
414 if (!err) {
415 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
416
417 err = crypto_authenc_genicv(areq, greq->giv, 0);
418 }
419
420 authenc_request_complete(areq, err);
421 }
422
crypto_authenc_givencrypt(struct aead_givcrypt_request * req)423 static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
424 {
425 struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
426 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
427 struct aead_request *areq = &req->areq;
428 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
429 u8 *iv = req->giv;
430 int err;
431
432 skcipher_givcrypt_set_tfm(greq, ctx->enc);
433 skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
434 crypto_authenc_givencrypt_done, areq);
435 skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
436 areq->iv);
437 skcipher_givcrypt_set_giv(greq, iv, req->seq);
438
439 err = crypto_skcipher_givencrypt(greq);
440 if (err)
441 return err;
442
443 return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
444 }
445
crypto_authenc_verify(struct aead_request * req,authenc_ahash_t authenc_ahash_fn)446 static int crypto_authenc_verify(struct aead_request *req,
447 authenc_ahash_t authenc_ahash_fn)
448 {
449 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
450 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
451 u8 *ohash;
452 u8 *ihash;
453 unsigned int authsize;
454
455 areq_ctx->complete = authenc_verify_ahash_done;
456 areq_ctx->update_complete = authenc_verify_ahash_update_done;
457
458 ohash = authenc_ahash_fn(req, CRYPTO_TFM_REQ_MAY_SLEEP);
459 if (IS_ERR(ohash))
460 return PTR_ERR(ohash);
461
462 authsize = crypto_aead_authsize(authenc);
463 ihash = ohash + authsize;
464 scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen,
465 authsize, 0);
466 return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0;
467 }
468
crypto_authenc_iverify(struct aead_request * req,u8 * iv,unsigned int cryptlen)469 static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
470 unsigned int cryptlen)
471 {
472 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
473 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
474 struct scatterlist *src = req->src;
475 struct scatterlist *assoc = req->assoc;
476 struct scatterlist *cipher = areq_ctx->cipher;
477 struct scatterlist *asg = areq_ctx->asg;
478 unsigned int ivsize = crypto_aead_ivsize(authenc);
479 authenc_ahash_t authenc_ahash_fn = crypto_authenc_ahash_fb;
480 struct page *srcp;
481 u8 *vsrc;
482
483 srcp = sg_page(src);
484 vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
485
486 if (ivsize) {
487 sg_init_table(cipher, 2);
488 sg_set_buf(cipher, iv, ivsize);
489 scatterwalk_crypto_chain(cipher, src, vsrc == iv + ivsize, 2);
490 src = cipher;
491 cryptlen += ivsize;
492 }
493
494 if (sg_is_last(assoc)) {
495 authenc_ahash_fn = crypto_authenc_ahash;
496 sg_init_table(asg, 2);
497 sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);
498 scatterwalk_crypto_chain(asg, src, 0, 2);
499 src = asg;
500 cryptlen += req->assoclen;
501 }
502
503 areq_ctx->cryptlen = cryptlen;
504 areq_ctx->sg = src;
505
506 return crypto_authenc_verify(req, authenc_ahash_fn);
507 }
508
crypto_authenc_decrypt(struct aead_request * req)509 static int crypto_authenc_decrypt(struct aead_request *req)
510 {
511 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
512 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
513 struct ablkcipher_request *abreq = aead_request_ctx(req);
514 unsigned int cryptlen = req->cryptlen;
515 unsigned int authsize = crypto_aead_authsize(authenc);
516 u8 *iv = req->iv;
517 int err;
518
519 if (cryptlen < authsize)
520 return -EINVAL;
521 cryptlen -= authsize;
522
523 err = crypto_authenc_iverify(req, iv, cryptlen);
524 if (err)
525 return err;
526
527 ablkcipher_request_set_tfm(abreq, ctx->enc);
528 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
529 req->base.complete, req->base.data);
530 ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
531
532 return crypto_ablkcipher_decrypt(abreq);
533 }
534
crypto_authenc_init_tfm(struct crypto_tfm * tfm)535 static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
536 {
537 struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
538 struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
539 struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
540 struct crypto_ahash *auth;
541 struct crypto_ablkcipher *enc;
542 int err;
543
544 auth = crypto_spawn_ahash(&ictx->auth);
545 if (IS_ERR(auth))
546 return PTR_ERR(auth);
547
548 enc = crypto_spawn_skcipher(&ictx->enc);
549 err = PTR_ERR(enc);
550 if (IS_ERR(enc))
551 goto err_free_ahash;
552
553 ctx->auth = auth;
554 ctx->enc = enc;
555
556 ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth) +
557 crypto_ahash_alignmask(auth),
558 crypto_ahash_alignmask(auth) + 1) +
559 crypto_ablkcipher_ivsize(enc);
560
561 tfm->crt_aead.reqsize = sizeof(struct authenc_request_ctx) +
562 ctx->reqoff +
563 max_t(unsigned int,
564 crypto_ahash_reqsize(auth) +
565 sizeof(struct ahash_request),
566 sizeof(struct skcipher_givcrypt_request) +
567 crypto_ablkcipher_reqsize(enc));
568
569 return 0;
570
571 err_free_ahash:
572 crypto_free_ahash(auth);
573 return err;
574 }
575
crypto_authenc_exit_tfm(struct crypto_tfm * tfm)576 static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
577 {
578 struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
579
580 crypto_free_ahash(ctx->auth);
581 crypto_free_ablkcipher(ctx->enc);
582 }
583
crypto_authenc_alloc(struct rtattr ** tb)584 static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
585 {
586 struct crypto_attr_type *algt;
587 struct crypto_instance *inst;
588 struct hash_alg_common *auth;
589 struct crypto_alg *auth_base;
590 struct crypto_alg *enc;
591 struct authenc_instance_ctx *ctx;
592 const char *enc_name;
593 int err;
594
595 algt = crypto_get_attr_type(tb);
596 err = PTR_ERR(algt);
597 if (IS_ERR(algt))
598 return ERR_PTR(err);
599
600 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
601 return ERR_PTR(-EINVAL);
602
603 auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
604 CRYPTO_ALG_TYPE_AHASH_MASK);
605 if (IS_ERR(auth))
606 return ERR_CAST(auth);
607
608 auth_base = &auth->base;
609
610 enc_name = crypto_attr_alg_name(tb[2]);
611 err = PTR_ERR(enc_name);
612 if (IS_ERR(enc_name))
613 goto out_put_auth;
614
615 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
616 err = -ENOMEM;
617 if (!inst)
618 goto out_put_auth;
619
620 ctx = crypto_instance_ctx(inst);
621
622 err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
623 if (err)
624 goto err_free_inst;
625
626 crypto_set_skcipher_spawn(&ctx->enc, inst);
627 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
628 crypto_requires_sync(algt->type,
629 algt->mask));
630 if (err)
631 goto err_drop_auth;
632
633 enc = crypto_skcipher_spawn_alg(&ctx->enc);
634
635 err = -ENAMETOOLONG;
636 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
637 "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
638 CRYPTO_MAX_ALG_NAME)
639 goto err_drop_enc;
640
641 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
642 "authenc(%s,%s)", auth_base->cra_driver_name,
643 enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
644 goto err_drop_enc;
645
646 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
647 inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
648 inst->alg.cra_priority = enc->cra_priority *
649 10 + auth_base->cra_priority;
650 inst->alg.cra_blocksize = enc->cra_blocksize;
651 inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
652 inst->alg.cra_type = &crypto_aead_type;
653
654 inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
655 inst->alg.cra_aead.maxauthsize = auth->digestsize;
656
657 inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
658
659 inst->alg.cra_init = crypto_authenc_init_tfm;
660 inst->alg.cra_exit = crypto_authenc_exit_tfm;
661
662 inst->alg.cra_aead.setkey = crypto_authenc_setkey;
663 inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
664 inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
665 inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
666
667 out:
668 crypto_mod_put(auth_base);
669 return inst;
670
671 err_drop_enc:
672 crypto_drop_skcipher(&ctx->enc);
673 err_drop_auth:
674 crypto_drop_ahash(&ctx->auth);
675 err_free_inst:
676 kfree(inst);
677 out_put_auth:
678 inst = ERR_PTR(err);
679 goto out;
680 }
681
crypto_authenc_free(struct crypto_instance * inst)682 static void crypto_authenc_free(struct crypto_instance *inst)
683 {
684 struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
685
686 crypto_drop_skcipher(&ctx->enc);
687 crypto_drop_ahash(&ctx->auth);
688 kfree(inst);
689 }
690
691 static struct crypto_template crypto_authenc_tmpl = {
692 .name = "authenc",
693 .alloc = crypto_authenc_alloc,
694 .free = crypto_authenc_free,
695 .module = THIS_MODULE,
696 };
697
crypto_authenc_module_init(void)698 static int __init crypto_authenc_module_init(void)
699 {
700 return crypto_register_template(&crypto_authenc_tmpl);
701 }
702
crypto_authenc_module_exit(void)703 static void __exit crypto_authenc_module_exit(void)
704 {
705 crypto_unregister_template(&crypto_authenc_tmpl);
706 }
707
708 module_init(crypto_authenc_module_init);
709 module_exit(crypto_authenc_module_exit);
710
711 MODULE_LICENSE("GPL");
712 MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
713