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