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Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
[net-next-2.6.git] / crypto / authenc.c
CommitLineData
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1/*
2 * Authenc: Simple AEAD wrapper for IPsec
3 *
4 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
e56dd564 13#include <crypto/aead.h>
5f7082ed 14#include <crypto/internal/hash.h>
9ffde35a 15#include <crypto/internal/skcipher.h>
e236d4a8 16#include <crypto/authenc.h>
42c271c6 17#include <crypto/scatterwalk.h>
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18#include <linux/err.h>
19#include <linux/init.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
e236d4a8 22#include <linux/rtnetlink.h>
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23#include <linux/slab.h>
24#include <linux/spinlock.h>
25
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26struct authenc_instance_ctx {
27 struct crypto_spawn auth;
9ffde35a 28 struct crypto_skcipher_spawn enc;
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29};
30
31struct crypto_authenc_ctx {
32 spinlock_t auth_lock;
33 struct crypto_hash *auth;
34 struct crypto_ablkcipher *enc;
35};
36
37static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
38 unsigned int keylen)
39{
3c09f17c 40 unsigned int authkeylen;
e236d4a8 41 unsigned int enckeylen;
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42 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
43 struct crypto_hash *auth = ctx->auth;
44 struct crypto_ablkcipher *enc = ctx->enc;
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45 struct rtattr *rta = (void *)key;
46 struct crypto_authenc_key_param *param;
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47 int err = -EINVAL;
48
12dc5e62 49 if (!RTA_OK(rta, keylen))
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50 goto badkey;
51 if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
52 goto badkey;
53 if (RTA_PAYLOAD(rta) < sizeof(*param))
54 goto badkey;
55
56 param = RTA_DATA(rta);
57 enckeylen = be32_to_cpu(param->enckeylen);
58
59 key += RTA_ALIGN(rta->rta_len);
60 keylen -= RTA_ALIGN(rta->rta_len);
61
62 if (keylen < enckeylen)
63 goto badkey;
64
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65 authkeylen = keylen - enckeylen;
66
67 crypto_hash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
68 crypto_hash_set_flags(auth, crypto_aead_get_flags(authenc) &
69 CRYPTO_TFM_REQ_MASK);
70 err = crypto_hash_setkey(auth, key, authkeylen);
71 crypto_aead_set_flags(authenc, crypto_hash_get_flags(auth) &
72 CRYPTO_TFM_RES_MASK);
73
74 if (err)
75 goto out;
76
77 crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
78 crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
79 CRYPTO_TFM_REQ_MASK);
80 err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
81 crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
82 CRYPTO_TFM_RES_MASK);
83
84out:
85 return err;
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86
87badkey:
88 crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
89 goto out;
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90}
91
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92static void authenc_chain(struct scatterlist *head, struct scatterlist *sg,
93 int chain)
94{
95 if (chain) {
96 head->length += sg->length;
97 sg = scatterwalk_sg_next(sg);
98 }
99
100 if (sg)
101 scatterwalk_sg_chain(head, 2, sg);
102 else
103 sg_mark_end(head);
104}
105
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106static u8 *crypto_authenc_hash(struct aead_request *req, unsigned int flags,
107 struct scatterlist *cipher,
108 unsigned int cryptlen)
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109{
110 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
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111 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
112 struct crypto_hash *auth = ctx->auth;
113 struct hash_desc desc = {
114 .tfm = auth,
7c3d703f 115 .flags = aead_request_flags(req) & flags,
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116 };
117 u8 *hash = aead_request_ctx(req);
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118 int err;
119
120 hash = (u8 *)ALIGN((unsigned long)hash + crypto_hash_alignmask(auth),
121 crypto_hash_alignmask(auth) + 1);
122
123 spin_lock_bh(&ctx->auth_lock);
124 err = crypto_hash_init(&desc);
125 if (err)
126 goto auth_unlock;
127
128 err = crypto_hash_update(&desc, req->assoc, req->assoclen);
129 if (err)
130 goto auth_unlock;
131
7c3d703f 132 err = crypto_hash_update(&desc, cipher, cryptlen);
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133 if (err)
134 goto auth_unlock;
135
136 err = crypto_hash_final(&desc, hash);
137auth_unlock:
138 spin_unlock_bh(&ctx->auth_lock);
139
140 if (err)
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141 return ERR_PTR(err);
142
143 return hash;
144}
145
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146static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
147 unsigned int flags)
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148{
149 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
150 struct scatterlist *dst = req->dst;
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151 struct scatterlist cipher[2];
152 struct page *dstp;
153 unsigned int ivsize = crypto_aead_ivsize(authenc);
154 unsigned int cryptlen;
155 u8 *vdst;
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156 u8 *hash;
157
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158 dstp = sg_page(dst);
159 vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
160
161 sg_init_table(cipher, 2);
162 sg_set_buf(cipher, iv, ivsize);
163 authenc_chain(cipher, dst, vdst == iv + ivsize);
164
165 cryptlen = req->cryptlen + ivsize;
166 hash = crypto_authenc_hash(req, flags, cipher, cryptlen);
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167 if (IS_ERR(hash))
168 return PTR_ERR(hash);
3c09f17c 169
e56dd564 170 scatterwalk_map_and_copy(hash, cipher, cryptlen,
7ba683a6 171 crypto_aead_authsize(authenc), 1);
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172 return 0;
173}
174
175static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
176 int err)
177{
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178 struct aead_request *areq = req->data;
179
e56dd564 180 if (!err) {
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181 struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
182 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
183 struct ablkcipher_request *abreq = aead_request_ctx(areq);
184 u8 *iv = (u8 *)(abreq + 1) +
185 crypto_ablkcipher_reqsize(ctx->enc);
186
187 err = crypto_authenc_genicv(areq, iv, 0);
188 }
3c09f17c 189
a697690b 190 aead_request_complete(areq, err);
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191}
192
193static int crypto_authenc_encrypt(struct aead_request *req)
194{
195 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
196 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
197 struct ablkcipher_request *abreq = aead_request_ctx(req);
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198 struct crypto_ablkcipher *enc = ctx->enc;
199 struct scatterlist *dst = req->dst;
200 unsigned int cryptlen = req->cryptlen;
201 u8 *iv = (u8 *)(abreq + 1) + crypto_ablkcipher_reqsize(enc);
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202 int err;
203
e56dd564 204 ablkcipher_request_set_tfm(abreq, enc);
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205 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
206 crypto_authenc_encrypt_done, req);
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207 ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
208
209 memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
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210
211 err = crypto_ablkcipher_encrypt(abreq);
212 if (err)
213 return err;
214
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215 return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
216}
217
218static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
219 int err)
220{
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221 struct aead_request *areq = req->data;
222
e56dd564 223 if (!err) {
16161329 224 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
e56dd564 225
16161329 226 err = crypto_authenc_genicv(areq, greq->giv, 0);
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227 }
228
a697690b 229 aead_request_complete(areq, err);
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230}
231
232static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
233{
234 struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
235 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
236 struct aead_request *areq = &req->areq;
237 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
238 u8 *iv = req->giv;
239 int err;
240
241 skcipher_givcrypt_set_tfm(greq, ctx->enc);
242 skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
243 crypto_authenc_givencrypt_done, areq);
244 skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
245 areq->iv);
246 skcipher_givcrypt_set_giv(greq, iv, req->seq);
247
248 err = crypto_skcipher_givencrypt(greq);
249 if (err)
250 return err;
251
252 return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
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253}
254
481f34ae 255static int crypto_authenc_verify(struct aead_request *req,
e56dd564 256 struct scatterlist *cipher,
481f34ae 257 unsigned int cryptlen)
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258{
259 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
7c3d703f 260 u8 *ohash;
3c09f17c 261 u8 *ihash;
3c09f17c 262 unsigned int authsize;
3c09f17c 263
e56dd564 264 ohash = crypto_authenc_hash(req, CRYPTO_TFM_REQ_MAY_SLEEP, cipher,
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265 cryptlen);
266 if (IS_ERR(ohash))
267 return PTR_ERR(ohash);
3c09f17c 268
7ba683a6 269 authsize = crypto_aead_authsize(authenc);
7c3d703f 270 ihash = ohash + authsize;
e56dd564 271 scatterwalk_map_and_copy(ihash, cipher, cryptlen, authsize, 0);
fe70f5df 272 return memcmp(ihash, ohash, authsize) ? -EBADMSG: 0;
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273}
274
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275static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
276 unsigned int cryptlen)
3c09f17c 277{
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278 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
279 struct scatterlist *src = req->src;
280 struct scatterlist cipher[2];
281 struct page *srcp;
282 unsigned int ivsize = crypto_aead_ivsize(authenc);
283 u8 *vsrc;
284
285 srcp = sg_page(src);
286 vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
287
288 sg_init_table(cipher, 2);
289 sg_set_buf(cipher, iv, ivsize);
290 authenc_chain(cipher, src, vsrc == iv + ivsize);
291
292 return crypto_authenc_verify(req, cipher, cryptlen + ivsize);
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293}
294
295static int crypto_authenc_decrypt(struct aead_request *req)
296{
297 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
298 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
299 struct ablkcipher_request *abreq = aead_request_ctx(req);
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300 unsigned int cryptlen = req->cryptlen;
301 unsigned int authsize = crypto_aead_authsize(authenc);
e56dd564 302 u8 *iv = req->iv;
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303 int err;
304
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305 if (cryptlen < authsize)
306 return -EINVAL;
307 cryptlen -= authsize;
308
e56dd564 309 err = crypto_authenc_iverify(req, iv, cryptlen);
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310 if (err)
311 return err;
312
313 ablkcipher_request_set_tfm(abreq, ctx->enc);
314 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
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315 req->base.complete, req->base.data);
316 ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
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317
318 return crypto_ablkcipher_decrypt(abreq);
319}
320
321static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
322{
323 struct crypto_instance *inst = (void *)tfm->__crt_alg;
324 struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
325 struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
326 struct crypto_hash *auth;
327 struct crypto_ablkcipher *enc;
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328 int err;
329
330 auth = crypto_spawn_hash(&ictx->auth);
331 if (IS_ERR(auth))
332 return PTR_ERR(auth);
333
9ffde35a 334 enc = crypto_spawn_skcipher(&ictx->enc);
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335 err = PTR_ERR(enc);
336 if (IS_ERR(enc))
337 goto err_free_hash;
338
339 ctx->auth = auth;
340 ctx->enc = enc;
341 tfm->crt_aead.reqsize = max_t(unsigned int,
342 (crypto_hash_alignmask(auth) &
343 ~(crypto_tfm_ctx_alignment() - 1)) +
7ba683a6 344 crypto_hash_digestsize(auth) * 2,
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345 sizeof(struct skcipher_givcrypt_request) +
346 crypto_ablkcipher_reqsize(enc) +
347 crypto_ablkcipher_ivsize(enc));
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348
349 spin_lock_init(&ctx->auth_lock);
350
351 return 0;
352
353err_free_hash:
354 crypto_free_hash(auth);
355 return err;
356}
357
358static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
359{
360 struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
361
362 crypto_free_hash(ctx->auth);
363 crypto_free_ablkcipher(ctx->enc);
364}
365
366static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
367{
9ffde35a 368 struct crypto_attr_type *algt;
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369 struct crypto_instance *inst;
370 struct crypto_alg *auth;
371 struct crypto_alg *enc;
372 struct authenc_instance_ctx *ctx;
9ffde35a 373 const char *enc_name;
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374 int err;
375
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376 algt = crypto_get_attr_type(tb);
377 err = PTR_ERR(algt);
378 if (IS_ERR(algt))
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379 return ERR_PTR(err);
380
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381 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
382 return ERR_PTR(-EINVAL);
383
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384 auth = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
385 CRYPTO_ALG_TYPE_HASH_MASK);
386 if (IS_ERR(auth))
387 return ERR_PTR(PTR_ERR(auth));
388
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389 enc_name = crypto_attr_alg_name(tb[2]);
390 err = PTR_ERR(enc_name);
391 if (IS_ERR(enc_name))
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392 goto out_put_auth;
393
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394 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
395 err = -ENOMEM;
396 if (!inst)
9ffde35a 397 goto out_put_auth;
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398
399 ctx = crypto_instance_ctx(inst);
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400
401 err = crypto_init_spawn(&ctx->auth, auth, inst, CRYPTO_ALG_TYPE_MASK);
402 if (err)
403 goto err_free_inst;
404
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405 crypto_set_skcipher_spawn(&ctx->enc, inst);
406 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
407 crypto_requires_sync(algt->type,
408 algt->mask));
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409 if (err)
410 goto err_drop_auth;
411
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412 enc = crypto_skcipher_spawn_alg(&ctx->enc);
413
414 err = -ENAMETOOLONG;
415 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
416 "authenc(%s,%s)", auth->cra_name, enc->cra_name) >=
417 CRYPTO_MAX_ALG_NAME)
418 goto err_drop_enc;
419
420 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
421 "authenc(%s,%s)", auth->cra_driver_name,
422 enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
423 goto err_drop_enc;
424
425 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
426 inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
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427 inst->alg.cra_priority = enc->cra_priority * 10 + auth->cra_priority;
428 inst->alg.cra_blocksize = enc->cra_blocksize;
e29bc6ad 429 inst->alg.cra_alignmask = auth->cra_alignmask | enc->cra_alignmask;
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430 inst->alg.cra_type = &crypto_aead_type;
431
c2c61f51 432 inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
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433 inst->alg.cra_aead.maxauthsize = auth->cra_type == &crypto_hash_type ?
434 auth->cra_hash.digestsize :
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435 auth->cra_type ?
436 __crypto_shash_alg(auth)->digestsize :
7ba683a6 437 auth->cra_digest.dia_digestsize;
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438
439 inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
440
441 inst->alg.cra_init = crypto_authenc_init_tfm;
442 inst->alg.cra_exit = crypto_authenc_exit_tfm;
443
444 inst->alg.cra_aead.setkey = crypto_authenc_setkey;
445 inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
446 inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
e56dd564 447 inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
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448
449out:
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450 crypto_mod_put(auth);
451 return inst;
452
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453err_drop_enc:
454 crypto_drop_skcipher(&ctx->enc);
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455err_drop_auth:
456 crypto_drop_spawn(&ctx->auth);
457err_free_inst:
458 kfree(inst);
9ffde35a 459out_put_auth:
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460 inst = ERR_PTR(err);
461 goto out;
462}
463
464static void crypto_authenc_free(struct crypto_instance *inst)
465{
466 struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
467
9ffde35a 468 crypto_drop_skcipher(&ctx->enc);
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469 crypto_drop_spawn(&ctx->auth);
470 kfree(inst);
471}
472
473static struct crypto_template crypto_authenc_tmpl = {
474 .name = "authenc",
475 .alloc = crypto_authenc_alloc,
476 .free = crypto_authenc_free,
477 .module = THIS_MODULE,
478};
479
480static int __init crypto_authenc_module_init(void)
481{
482 return crypto_register_template(&crypto_authenc_tmpl);
483}
484
485static void __exit crypto_authenc_module_exit(void)
486{
487 crypto_unregister_template(&crypto_authenc_tmpl);
488}
489
490module_init(crypto_authenc_module_init);
491module_exit(crypto_authenc_module_exit);
492
493MODULE_LICENSE("GPL");
494MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");