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 = crypto_memneq(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 = crypto_memneq(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 (req->assoclen && 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 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
crypto_authenc_encrypt(struct aead_request * req)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
crypto_authenc_givencrypt_done(struct crypto_async_request * req,int err)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
crypto_authenc_givencrypt(struct aead_givcrypt_request * req)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
crypto_authenc_verify(struct aead_request * req,authenc_ahash_t authenc_ahash_fn)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 crypto_memneq(ihash, ohash, authsize) ? -EBADMSG : 0;
466 }
467
crypto_authenc_iverify(struct aead_request * req,u8 * iv,unsigned int cryptlen)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 (req->assoclen && 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
crypto_authenc_decrypt(struct aead_request * req)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
crypto_authenc_init_tfm(struct crypto_tfm * tfm)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
crypto_authenc_exit_tfm(struct crypto_tfm * tfm)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
crypto_authenc_alloc(struct rtattr ** tb)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 if (IS_ERR(algt))
596 return ERR_CAST(algt);
597
598 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
599 return ERR_PTR(-EINVAL);
600
601 auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
602 CRYPTO_ALG_TYPE_AHASH_MASK);
603 if (IS_ERR(auth))
604 return ERR_CAST(auth);
605
606 auth_base = &auth->base;
607
608 enc_name = crypto_attr_alg_name(tb[2]);
609 err = PTR_ERR(enc_name);
610 if (IS_ERR(enc_name))
611 goto out_put_auth;
612
613 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
614 err = -ENOMEM;
615 if (!inst)
616 goto out_put_auth;
617
618 ctx = crypto_instance_ctx(inst);
619
620 err = crypto_init_ahash_spawn(&ctx->auth, auth, inst);
621 if (err)
622 goto err_free_inst;
623
624 crypto_set_skcipher_spawn(&ctx->enc, inst);
625 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
626 crypto_requires_sync(algt->type,
627 algt->mask));
628 if (err)
629 goto err_drop_auth;
630
631 enc = crypto_skcipher_spawn_alg(&ctx->enc);
632
633 err = -ENAMETOOLONG;
634 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
635 "authenc(%s,%s)", auth_base->cra_name, enc->cra_name) >=
636 CRYPTO_MAX_ALG_NAME)
637 goto err_drop_enc;
638
639 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
640 "authenc(%s,%s)", auth_base->cra_driver_name,
641 enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
642 goto err_drop_enc;
643
644 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
645 inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
646 inst->alg.cra_priority = enc->cra_priority *
647 10 + auth_base->cra_priority;
648 inst->alg.cra_blocksize = enc->cra_blocksize;
649 inst->alg.cra_alignmask = auth_base->cra_alignmask | enc->cra_alignmask;
650 inst->alg.cra_type = &crypto_aead_type;
651
652 inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
653 inst->alg.cra_aead.maxauthsize = auth->digestsize;
654
655 inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
656
657 inst->alg.cra_init = crypto_authenc_init_tfm;
658 inst->alg.cra_exit = crypto_authenc_exit_tfm;
659
660 inst->alg.cra_aead.setkey = crypto_authenc_setkey;
661 inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
662 inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
663 inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
664
665 out:
666 crypto_mod_put(auth_base);
667 return inst;
668
669 err_drop_enc:
670 crypto_drop_skcipher(&ctx->enc);
671 err_drop_auth:
672 crypto_drop_ahash(&ctx->auth);
673 err_free_inst:
674 kfree(inst);
675 out_put_auth:
676 inst = ERR_PTR(err);
677 goto out;
678 }
679
crypto_authenc_free(struct crypto_instance * inst)680 static void crypto_authenc_free(struct crypto_instance *inst)
681 {
682 struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
683
684 crypto_drop_skcipher(&ctx->enc);
685 crypto_drop_ahash(&ctx->auth);
686 kfree(inst);
687 }
688
689 static struct crypto_template crypto_authenc_tmpl = {
690 .name = "authenc",
691 .alloc = crypto_authenc_alloc,
692 .free = crypto_authenc_free,
693 .module = THIS_MODULE,
694 };
695
crypto_authenc_module_init(void)696 static int __init crypto_authenc_module_init(void)
697 {
698 return crypto_register_template(&crypto_authenc_tmpl);
699 }
700
crypto_authenc_module_exit(void)701 static void __exit crypto_authenc_module_exit(void)
702 {
703 crypto_unregister_template(&crypto_authenc_tmpl);
704 }
705
706 module_init(crypto_authenc_module_init);
707 module_exit(crypto_authenc_module_exit);
708
709 MODULE_LICENSE("GPL");
710 MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
711