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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_ablkcipher *enc;
39 struct crypto_blkcipher *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_ablkcipher *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_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
86 crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc_esn) &
87 CRYPTO_TFM_REQ_MASK);
88 err = crypto_ablkcipher_setkey(enc, keys.enckey, keys.enckeylen);
89 crypto_aead_set_flags(authenc_esn, crypto_ablkcipher_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 struct blkcipher_desc desc = {
186 .tfm = ctx->null,
187 };
188
189 return crypto_blkcipher_encrypt(&desc, req->dst, req->src, len);
190}
191
192static int crypto_authenc_esn_encrypt(struct aead_request *req)
193{
194 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
195 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
196 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
197 struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
198 + ctx->reqoff);
199 struct crypto_ablkcipher *enc = ctx->enc;
200 unsigned int assoclen = req->assoclen;
201 unsigned int cryptlen = req->cryptlen;
202 struct scatterlist *src, *dst;
203 int err;
204
205 sg_init_table(areq_ctx->src, 2);
206 src = scatterwalk_ffwd(areq_ctx->src, req->src, assoclen);
207 dst = src;
208
209 if (req->src != req->dst) {
210 err = crypto_authenc_esn_copy(req, assoclen);
211 if (err)
212 return err;
213
214 sg_init_table(areq_ctx->dst, 2);
215 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, assoclen);
216 }
217
218 ablkcipher_request_set_tfm(abreq, enc);
219 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
220 crypto_authenc_esn_encrypt_done, req);
221 ablkcipher_request_set_crypt(abreq, src, dst, cryptlen, req->iv);
222
223 err = crypto_ablkcipher_encrypt(abreq);
224 if (err)
225 return err;
226
227 return crypto_authenc_esn_genicv(req, aead_request_flags(req));
228}
229
230static int crypto_authenc_esn_decrypt_tail(struct aead_request *req,
231 unsigned int flags)
232{
233 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
234 unsigned int authsize = crypto_aead_authsize(authenc_esn);
235 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
236 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
237 struct ablkcipher_request *abreq = (void *)(areq_ctx->tail
238 + ctx->reqoff);
239 struct crypto_ahash *auth = ctx->auth;
240 u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail,
241 crypto_ahash_alignmask(auth) + 1);
242 unsigned int cryptlen = req->cryptlen - authsize;
243 unsigned int assoclen = req->assoclen;
244 struct scatterlist *dst = req->dst;
245 u8 *ihash = ohash + crypto_ahash_digestsize(auth);
246 u32 tmp[2];
247
248
249 scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
250 scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
251 scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);
252
253 if (crypto_memneq(ihash, ohash, authsize))
254 return -EBADMSG;
255
256 sg_init_table(areq_ctx->dst, 2);
257 dst = scatterwalk_ffwd(areq_ctx->dst, dst, assoclen);
258
259 ablkcipher_request_set_tfm(abreq, ctx->enc);
260 ablkcipher_request_set_callback(abreq, flags,
261 req->base.complete, req->base.data);
262 ablkcipher_request_set_crypt(abreq, dst, dst, cryptlen, req->iv);
263
264 return crypto_ablkcipher_decrypt(abreq);
265}
266
267static void authenc_esn_verify_ahash_done(struct crypto_async_request *areq,
268 int err)
269{
270 struct aead_request *req = areq->data;
271
272 err = err ?: crypto_authenc_esn_decrypt_tail(req, 0);
273 aead_request_complete(req, err);
274}
275
276static int crypto_authenc_esn_decrypt(struct aead_request *req)
277{
278 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
279 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
280 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
281 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff);
282 unsigned int authsize = crypto_aead_authsize(authenc_esn);
283 struct crypto_ahash *auth = ctx->auth;
284 u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail,
285 crypto_ahash_alignmask(auth) + 1);
286 unsigned int assoclen = req->assoclen;
287 unsigned int cryptlen = req->cryptlen;
288 u8 *ihash = ohash + crypto_ahash_digestsize(auth);
289 struct scatterlist *dst = req->dst;
290 u32 tmp[2];
291 int err;
292
293 cryptlen -= authsize;
294
295 if (req->src != dst) {
296 err = crypto_authenc_esn_copy(req, assoclen + cryptlen);
297 if (err)
298 return err;
299 }
300
301 scatterwalk_map_and_copy(ihash, req->src, assoclen + cryptlen,
302 authsize, 0);
303
304 if (!authsize)
305 goto tail;
306
307
308 scatterwalk_map_and_copy(tmp, dst, 0, 8, 0);
309 scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
310 scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);
311
312 sg_init_table(areq_ctx->dst, 2);
313 dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);
314
315 ahash_request_set_tfm(ahreq, auth);
316 ahash_request_set_crypt(ahreq, dst, ohash, assoclen + cryptlen);
317 ahash_request_set_callback(ahreq, aead_request_flags(req),
318 authenc_esn_verify_ahash_done, req);
319
320 err = crypto_ahash_digest(ahreq);
321 if (err)
322 return err;
323
324tail:
325 return crypto_authenc_esn_decrypt_tail(req, aead_request_flags(req));
326}
327
328static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm)
329{
330 struct aead_instance *inst = aead_alg_instance(tfm);
331 struct authenc_esn_instance_ctx *ictx = aead_instance_ctx(inst);
332 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);
333 struct crypto_ahash *auth;
334 struct crypto_ablkcipher *enc;
335 struct crypto_blkcipher *null;
336 int err;
337
338 auth = crypto_spawn_ahash(&ictx->auth);
339 if (IS_ERR(auth))
340 return PTR_ERR(auth);
341
342 enc = crypto_spawn_skcipher(&ictx->enc);
343 err = PTR_ERR(enc);
344 if (IS_ERR(enc))
345 goto err_free_ahash;
346
347 null = crypto_get_default_null_skcipher();
348 err = PTR_ERR(null);
349 if (IS_ERR(null))
350 goto err_free_skcipher;
351
352 ctx->auth = auth;
353 ctx->enc = enc;
354 ctx->null = null;
355
356 ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth),
357 crypto_ahash_alignmask(auth) + 1);
358
359 crypto_aead_set_reqsize(
360 tfm,
361 sizeof(struct authenc_esn_request_ctx) +
362 ctx->reqoff +
363 max_t(unsigned int,
364 crypto_ahash_reqsize(auth) +
365 sizeof(struct ahash_request),
366 sizeof(struct skcipher_givcrypt_request) +
367 crypto_ablkcipher_reqsize(enc)));
368
369 return 0;
370
371err_free_skcipher:
372 crypto_free_ablkcipher(enc);
373err_free_ahash:
374 crypto_free_ahash(auth);
375 return err;
376}
377
378static void crypto_authenc_esn_exit_tfm(struct crypto_aead *tfm)
379{
380 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);
381
382 crypto_free_ahash(ctx->auth);
383 crypto_free_ablkcipher(ctx->enc);
384 crypto_put_default_null_skcipher();
385}
386
387static void crypto_authenc_esn_free(struct aead_instance *inst)
388{
389 struct authenc_esn_instance_ctx *ctx = aead_instance_ctx(inst);
390
391 crypto_drop_skcipher(&ctx->enc);
392 crypto_drop_ahash(&ctx->auth);
393 kfree(inst);
394}
395
396static int crypto_authenc_esn_create(struct crypto_template *tmpl,
397 struct rtattr **tb)
398{
399 struct crypto_attr_type *algt;
400 struct aead_instance *inst;
401 struct hash_alg_common *auth;
402 struct crypto_alg *auth_base;
403 struct crypto_alg *enc;
404 struct authenc_esn_instance_ctx *ctx;
405 const char *enc_name;
406 int err;
407
408 algt = crypto_get_attr_type(tb);
409 if (IS_ERR(algt))
410 return PTR_ERR(algt);
411
412 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
413 return -EINVAL;
414
415 auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
416 CRYPTO_ALG_TYPE_AHASH_MASK);
417 if (IS_ERR(auth))
418 return PTR_ERR(auth);
419
420 auth_base = &auth->base;
421
422 enc_name = crypto_attr_alg_name(tb[2]);
423 err = PTR_ERR(enc_name);
424 if (IS_ERR(enc_name))
425 goto out_put_auth;
426
427 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
428 err = -ENOMEM;
429 if (!inst)
430 goto out_put_auth;
431
432 ctx = aead_instance_ctx(inst);
433
434 err = crypto_init_ahash_spawn(&ctx->auth, auth,
435 aead_crypto_instance(inst));
436 if (err)
437 goto err_free_inst;
438
439 crypto_set_skcipher_spawn(&ctx->enc, aead_crypto_instance(inst));
440 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
441 crypto_requires_sync(algt->type,
442 algt->mask));
443 if (err)
444 goto err_drop_auth;
445
446 enc = crypto_skcipher_spawn_alg(&ctx->enc);
447
448 err = -ENAMETOOLONG;
449 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
450 "authencesn(%s,%s)", auth_base->cra_name,
451 enc->cra_name) >= CRYPTO_MAX_ALG_NAME)
452 goto err_drop_enc;
453
454 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
455 "authencesn(%s,%s)", auth_base->cra_driver_name,
456 enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
457 goto err_drop_enc;
458
459 inst->alg.base.cra_flags = enc->cra_flags & CRYPTO_ALG_ASYNC;
460 inst->alg.base.cra_priority = enc->cra_priority * 10 +
461 auth_base->cra_priority;
462 inst->alg.base.cra_blocksize = enc->cra_blocksize;
463 inst->alg.base.cra_alignmask = auth_base->cra_alignmask |
464 enc->cra_alignmask;
465 inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_esn_ctx);
466
467 inst->alg.ivsize = enc->cra_ablkcipher.ivsize;
468 inst->alg.maxauthsize = auth->digestsize;
469
470 inst->alg.init = crypto_authenc_esn_init_tfm;
471 inst->alg.exit = crypto_authenc_esn_exit_tfm;
472
473 inst->alg.setkey = crypto_authenc_esn_setkey;
474 inst->alg.setauthsize = crypto_authenc_esn_setauthsize;
475 inst->alg.encrypt = crypto_authenc_esn_encrypt;
476 inst->alg.decrypt = crypto_authenc_esn_decrypt;
477
478 inst->free = crypto_authenc_esn_free,
479
480 err = aead_register_instance(tmpl, inst);
481 if (err)
482 goto err_drop_enc;
483
484out:
485 crypto_mod_put(auth_base);
486 return err;
487
488err_drop_enc:
489 crypto_drop_skcipher(&ctx->enc);
490err_drop_auth:
491 crypto_drop_ahash(&ctx->auth);
492err_free_inst:
493 kfree(inst);
494out_put_auth:
495 goto out;
496}
497
498static struct crypto_template crypto_authenc_esn_tmpl = {
499 .name = "authencesn",
500 .create = crypto_authenc_esn_create,
501 .module = THIS_MODULE,
502};
503
504static int __init crypto_authenc_esn_module_init(void)
505{
506 return crypto_register_template(&crypto_authenc_esn_tmpl);
507}
508
509static void __exit crypto_authenc_esn_module_exit(void)
510{
511 crypto_unregister_template(&crypto_authenc_esn_tmpl);
512}
513
514module_init(crypto_authenc_esn_module_init);
515module_exit(crypto_authenc_esn_module_exit);
516
517MODULE_LICENSE("GPL");
518MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
519MODULE_DESCRIPTION("AEAD wrapper for IPsec with extended sequence numbers");
520MODULE_ALIAS_CRYPTO("authencesn");
521
