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16#include <crypto/internal/aead.h>
17#include <crypto/internal/hash.h>
18#include <crypto/internal/skcipher.h>
19#include <crypto/authenc.h>
20#include <crypto/null.h>
21#include <crypto/scatterwalk.h>
22#include <linux/err.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/rtnetlink.h>
27#include <linux/slab.h>
28#include <linux/spinlock.h>
29
30struct authenc_esn_instance_ctx {
31 struct crypto_ahash_spawn auth;
32 struct crypto_skcipher_spawn enc;
33};
34
35struct crypto_authenc_esn_ctx {
36 unsigned int reqoff;
37 struct crypto_ahash *auth;
38 struct crypto_skcipher *enc;
39 struct crypto_skcipher *null;
40};
41
42struct authenc_esn_request_ctx {
43 struct scatterlist src[2];
44 struct scatterlist dst[2];
45 char tail[];
46};
47
48static void authenc_esn_request_complete(struct aead_request *req, int err)
49{
50 if (err != -EINPROGRESS)
51 aead_request_complete(req, err);
52}
53
54static int crypto_authenc_esn_setauthsize(struct crypto_aead *authenc_esn,
55 unsigned int authsize)
56{
57 if (authsize > 0 && authsize < 4)
58 return -EINVAL;
59
60 return 0;
61}
62
63static int crypto_authenc_esn_setkey(struct crypto_aead *authenc_esn, const u8 *key,
64 unsigned int keylen)
65{
66 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
67 struct crypto_ahash *auth = ctx->auth;
68 struct crypto_skcipher *enc = ctx->enc;
69 struct crypto_authenc_keys keys;
70 int err = -EINVAL;
71
72 if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
73 goto badkey;
74
75 crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
76 crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc_esn) &
77 CRYPTO_TFM_REQ_MASK);
78 err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
79 crypto_aead_set_flags(authenc_esn, crypto_ahash_get_flags(auth) &
80 CRYPTO_TFM_RES_MASK);
81
82 if (err)
83 goto out;
84
85 crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
86 crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc_esn) &
87 CRYPTO_TFM_REQ_MASK);
88 err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
89 crypto_aead_set_flags(authenc_esn, crypto_skcipher_get_flags(enc) &
90 CRYPTO_TFM_RES_MASK);
91
92out:
93 return err;
94
95badkey:
96 crypto_aead_set_flags(authenc_esn, CRYPTO_TFM_RES_BAD_KEY_LEN);
97 goto out;
98}
99
100static int crypto_authenc_esn_genicv_tail(struct aead_request *req,
101 unsigned int flags)
102{
103 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
104 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
105 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
106 struct crypto_ahash *auth = ctx->auth;
107 u8 *hash = PTR_ALIGN((u8 *)areq_ctx->tail,
108 crypto_ahash_alignmask(auth) + 1);
109 unsigned int authsize = crypto_aead_authsize(authenc_esn);
110 unsigned int assoclen = req->assoclen;
111 unsigned int cryptlen = req->cryptlen;
112 struct scatterlist *dst = req->dst;
113 u32 tmp[2];
114
115
116 scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
117 scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
118 scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);
119
120 scatterwalk_map_and_copy(hash, dst, assoclen + cryptlen, authsize, 1);
121 return 0;
122}
123
124static void authenc_esn_geniv_ahash_done(struct crypto_async_request *areq,
125 int err)
126{
127 struct aead_request *req = areq->data;
128
129 err = err ?: crypto_authenc_esn_genicv_tail(req, 0);
130 aead_request_complete(req, err);
131}
132
133static int crypto_authenc_esn_genicv(struct aead_request *req,
134 unsigned int flags)
135{
136 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
137 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
138 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
139 struct crypto_ahash *auth = ctx->auth;
140 u8 *hash = PTR_ALIGN((u8 *)areq_ctx->tail,
141 crypto_ahash_alignmask(auth) + 1);
142 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
143 unsigned int authsize = crypto_aead_authsize(authenc_esn);
144 unsigned int assoclen = req->assoclen;
145 unsigned int cryptlen = req->cryptlen;
146 struct scatterlist *dst = req->dst;
147 u32 tmp[2];
148
149 if (!authsize)
150 return 0;
151
152
153 scatterwalk_map_and_copy(tmp, dst, 0, 8, 0);
154 scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
155 scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);
156
157 sg_init_table(areq_ctx->dst, 2);
158 dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);
159
160 ahash_request_set_tfm(ahreq, auth);
161 ahash_request_set_crypt(ahreq, dst, hash, assoclen + cryptlen);
162 ahash_request_set_callback(ahreq, flags,
163 authenc_esn_geniv_ahash_done, req);
164
165 return crypto_ahash_digest(ahreq) ?:
166 crypto_authenc_esn_genicv_tail(req, aead_request_flags(req));
167}
168
169
170static void crypto_authenc_esn_encrypt_done(struct crypto_async_request *req,
171 int err)
172{
173 struct aead_request *areq = req->data;
174
175 if (!err)
176 err = crypto_authenc_esn_genicv(areq, 0);
177
178 authenc_esn_request_complete(areq, err);
179}
180
181static int crypto_authenc_esn_copy(struct aead_request *req, unsigned int len)
182{
183 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
184 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
185 SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
186
187 skcipher_request_set_tfm(skreq, ctx->null);
188 skcipher_request_set_callback(skreq, aead_request_flags(req),
189 NULL, NULL);
190 skcipher_request_set_crypt(skreq, req->src, req->dst, len, NULL);
191
192 return crypto_skcipher_encrypt(skreq);
193}
194
195static int crypto_authenc_esn_encrypt(struct aead_request *req)
196{
197 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
198 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
199 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
200 struct skcipher_request *skreq = (void *)(areq_ctx->tail +
201 ctx->reqoff);
202 struct crypto_skcipher *enc = ctx->enc;
203 unsigned int assoclen = req->assoclen;
204 unsigned int cryptlen = req->cryptlen;
205 struct scatterlist *src, *dst;
206 int err;
207
208 sg_init_table(areq_ctx->src, 2);
209 src = scatterwalk_ffwd(areq_ctx->src, req->src, assoclen);
210 dst = src;
211
212 if (req->src != req->dst) {
213 err = crypto_authenc_esn_copy(req, assoclen);
214 if (err)
215 return err;
216
217 sg_init_table(areq_ctx->dst, 2);
218 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, assoclen);
219 }
220
221 skcipher_request_set_tfm(skreq, enc);
222 skcipher_request_set_callback(skreq, aead_request_flags(req),
223 crypto_authenc_esn_encrypt_done, req);
224 skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
225
226 err = crypto_skcipher_encrypt(skreq);
227 if (err)
228 return err;
229
230 return crypto_authenc_esn_genicv(req, aead_request_flags(req));
231}
232
233static int crypto_authenc_esn_decrypt_tail(struct aead_request *req,
234 unsigned int flags)
235{
236 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
237 unsigned int authsize = crypto_aead_authsize(authenc_esn);
238 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
239 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
240 struct skcipher_request *skreq = (void *)(areq_ctx->tail +
241 ctx->reqoff);
242 struct crypto_ahash *auth = ctx->auth;
243 u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail,
244 crypto_ahash_alignmask(auth) + 1);
245 unsigned int cryptlen = req->cryptlen - authsize;
246 unsigned int assoclen = req->assoclen;
247 struct scatterlist *dst = req->dst;
248 u8 *ihash = ohash + crypto_ahash_digestsize(auth);
249 u32 tmp[2];
250
251 if (!authsize)
252 goto decrypt;
253
254
255 scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
256 scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
257 scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);
258
259 if (crypto_memneq(ihash, ohash, authsize))
260 return -EBADMSG;
261
262decrypt:
263
264 sg_init_table(areq_ctx->dst, 2);
265 dst = scatterwalk_ffwd(areq_ctx->dst, dst, assoclen);
266
267 skcipher_request_set_tfm(skreq, ctx->enc);
268 skcipher_request_set_callback(skreq, flags,
269 req->base.complete, req->base.data);
270 skcipher_request_set_crypt(skreq, dst, dst, cryptlen, req->iv);
271
272 return crypto_skcipher_decrypt(skreq);
273}
274
275static void authenc_esn_verify_ahash_done(struct crypto_async_request *areq,
276 int err)
277{
278 struct aead_request *req = areq->data;
279
280 err = err ?: crypto_authenc_esn_decrypt_tail(req, 0);
281 aead_request_complete(req, err);
282}
283
284static int crypto_authenc_esn_decrypt(struct aead_request *req)
285{
286 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
287 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
288 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
289 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
290 unsigned int authsize = crypto_aead_authsize(authenc_esn);
291 struct crypto_ahash *auth = ctx->auth;
292 u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail,
293 crypto_ahash_alignmask(auth) + 1);
294 unsigned int assoclen = req->assoclen;
295 unsigned int cryptlen = req->cryptlen;
296 u8 *ihash = ohash + crypto_ahash_digestsize(auth);
297 struct scatterlist *dst = req->dst;
298 u32 tmp[2];
299 int err;
300
301 cryptlen -= authsize;
302
303 if (req->src != dst) {
304 err = crypto_authenc_esn_copy(req, assoclen + cryptlen);
305 if (err)
306 return err;
307 }
308
309 scatterwalk_map_and_copy(ihash, req->src, assoclen + cryptlen,
310 authsize, 0);
311
312 if (!authsize)
313 goto tail;
314
315
316 scatterwalk_map_and_copy(tmp, dst, 0, 8, 0);
317 scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
318 scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);
319
320 sg_init_table(areq_ctx->dst, 2);
321 dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);
322
323 ahash_request_set_tfm(ahreq, auth);
324 ahash_request_set_crypt(ahreq, dst, ohash, assoclen + cryptlen);
325 ahash_request_set_callback(ahreq, aead_request_flags(req),
326 authenc_esn_verify_ahash_done, req);
327
328 err = crypto_ahash_digest(ahreq);
329 if (err)
330 return err;
331
332tail:
333 return crypto_authenc_esn_decrypt_tail(req, aead_request_flags(req));
334}
335
336static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm)
337{
338 struct aead_instance *inst = aead_alg_instance(tfm);
339 struct authenc_esn_instance_ctx *ictx = aead_instance_ctx(inst);
340 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);
341 struct crypto_ahash *auth;
342 struct crypto_skcipher *enc;
343 struct crypto_skcipher *null;
344 int err;
345
346 auth = crypto_spawn_ahash(&ictx->auth);
347 if (IS_ERR(auth))
348 return PTR_ERR(auth);
349
350 enc = crypto_spawn_skcipher(&ictx->enc);
351 err = PTR_ERR(enc);
352 if (IS_ERR(enc))
353 goto err_free_ahash;
354
355 null = crypto_get_default_null_skcipher();
356 err = PTR_ERR(null);
357 if (IS_ERR(null))
358 goto err_free_skcipher;
359
360 ctx->auth = auth;
361 ctx->enc = enc;
362 ctx->null = null;
363
364 ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth),
365 crypto_ahash_alignmask(auth) + 1);
366
367 crypto_aead_set_reqsize(
368 tfm,
369 sizeof(struct authenc_esn_request_ctx) +
370 ctx->reqoff +
371 max_t(unsigned int,
372 crypto_ahash_reqsize(auth) +
373 sizeof(struct ahash_request),
374 sizeof(struct skcipher_request) +
375 crypto_skcipher_reqsize(enc)));
376
377 return 0;
378
379err_free_skcipher:
380 crypto_free_skcipher(enc);
381err_free_ahash:
382 crypto_free_ahash(auth);
383 return err;
384}
385
386static void crypto_authenc_esn_exit_tfm(struct crypto_aead *tfm)
387{
388 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);
389
390 crypto_free_ahash(ctx->auth);
391 crypto_free_skcipher(ctx->enc);
392 crypto_put_default_null_skcipher();
393}
394
395static void crypto_authenc_esn_free(struct aead_instance *inst)
396{
397 struct authenc_esn_instance_ctx *ctx = aead_instance_ctx(inst);
398
399 crypto_drop_skcipher(&ctx->enc);
400 crypto_drop_ahash(&ctx->auth);
401 kfree(inst);
402}
403
404static int crypto_authenc_esn_create(struct crypto_template *tmpl,
405 struct rtattr **tb)
406{
407 struct crypto_attr_type *algt;
408 struct aead_instance *inst;
409 struct hash_alg_common *auth;
410 struct crypto_alg *auth_base;
411 struct skcipher_alg *enc;
412 struct authenc_esn_instance_ctx *ctx;
413 const char *enc_name;
414 int err;
415
416 algt = crypto_get_attr_type(tb);
417 if (IS_ERR(algt))
418 return PTR_ERR(algt);
419
420 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
421 return -EINVAL;
422
423 auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
424 CRYPTO_ALG_TYPE_AHASH_MASK |
425 crypto_requires_sync(algt->type, algt->mask));
426 if (IS_ERR(auth))
427 return PTR_ERR(auth);
428
429 auth_base = &auth->base;
430
431 enc_name = crypto_attr_alg_name(tb[2]);
432 err = PTR_ERR(enc_name);
433 if (IS_ERR(enc_name))
434 goto out_put_auth;
435
436 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
437 err = -ENOMEM;
438 if (!inst)
439 goto out_put_auth;
440
441 ctx = aead_instance_ctx(inst);
442
443 err = crypto_init_ahash_spawn(&ctx->auth, auth,
444 aead_crypto_instance(inst));
445 if (err)
446 goto err_free_inst;
447
448 crypto_set_skcipher_spawn(&ctx->enc, aead_crypto_instance(inst));
449 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
450 crypto_requires_sync(algt->type,
451 algt->mask));
452 if (err)
453 goto err_drop_auth;
454
455 enc = crypto_spawn_skcipher_alg(&ctx->enc);
456
457 err = -ENAMETOOLONG;
458 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
459 "authencesn(%s,%s)", auth_base->cra_name,
460 enc->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
461 goto err_drop_enc;
462
463 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
464 "authencesn(%s,%s)", auth_base->cra_driver_name,
465 enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
466 goto err_drop_enc;
467
468 inst->alg.base.cra_flags = (auth_base->cra_flags |
469 enc->base.cra_flags) & CRYPTO_ALG_ASYNC;
470 inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
471 auth_base->cra_priority;
472 inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
473 inst->alg.base.cra_alignmask = auth_base->cra_alignmask |
474 enc->base.cra_alignmask;
475 inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_esn_ctx);
476
477 inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc);
478 inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc);
479 inst->alg.maxauthsize = auth->digestsize;
480
481 inst->alg.init = crypto_authenc_esn_init_tfm;
482 inst->alg.exit = crypto_authenc_esn_exit_tfm;
483
484 inst->alg.setkey = crypto_authenc_esn_setkey;
485 inst->alg.setauthsize = crypto_authenc_esn_setauthsize;
486 inst->alg.encrypt = crypto_authenc_esn_encrypt;
487 inst->alg.decrypt = crypto_authenc_esn_decrypt;
488
489 inst->free = crypto_authenc_esn_free,
490
491 err = aead_register_instance(tmpl, inst);
492 if (err)
493 goto err_drop_enc;
494
495out:
496 crypto_mod_put(auth_base);
497 return err;
498
499err_drop_enc:
500 crypto_drop_skcipher(&ctx->enc);
501err_drop_auth:
502 crypto_drop_ahash(&ctx->auth);
503err_free_inst:
504 kfree(inst);
505out_put_auth:
506 goto out;
507}
508
509static struct crypto_template crypto_authenc_esn_tmpl = {
510 .name = "authencesn",
511 .create = crypto_authenc_esn_create,
512 .module = THIS_MODULE,
513};
514
515static int __init crypto_authenc_esn_module_init(void)
516{
517 return crypto_register_template(&crypto_authenc_esn_tmpl);
518}
519
520static void __exit crypto_authenc_esn_module_exit(void)
521{
522 crypto_unregister_template(&crypto_authenc_esn_tmpl);
523}
524
525module_init(crypto_authenc_esn_module_init);
526module_exit(crypto_authenc_esn_module_exit);
527
528MODULE_LICENSE("GPL");
529MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
530MODULE_DESCRIPTION("AEAD wrapper for IPsec with extended sequence numbers");
531MODULE_ALIAS_CRYPTO("authencesn");
532
