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13#include <crypto/internal/aead.h>
14#include <crypto/internal/hash.h>
15#include <crypto/internal/skcipher.h>
16#include <crypto/authenc.h>
17#include <crypto/null.h>
18#include <crypto/scatterwalk.h>
19#include <linux/err.h>
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/rtnetlink.h>
24#include <linux/slab.h>
25#include <linux/spinlock.h>
26
27struct authenc_instance_ctx {
28 struct crypto_ahash_spawn auth;
29 struct crypto_skcipher_spawn enc;
30 unsigned int reqoff;
31};
32
33struct crypto_authenc_ctx {
34 struct crypto_ahash *auth;
35 struct crypto_skcipher *enc;
36 struct crypto_skcipher *null;
37};
38
39struct authenc_request_ctx {
40 struct scatterlist src[2];
41 struct scatterlist dst[2];
42 char tail[];
43};
44
45static void authenc_request_complete(struct aead_request *req, int err)
46{
47 if (err != -EINPROGRESS)
48 aead_request_complete(req, err);
49}
50
51int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
52 unsigned int keylen)
53{
54 struct rtattr *rta = (struct rtattr *)key;
55 struct crypto_authenc_key_param *param;
56
57 if (!RTA_OK(rta, keylen))
58 return -EINVAL;
59 if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
60 return -EINVAL;
61 if (RTA_PAYLOAD(rta) < sizeof(*param))
62 return -EINVAL;
63
64 param = RTA_DATA(rta);
65 keys->enckeylen = be32_to_cpu(param->enckeylen);
66
67 key += RTA_ALIGN(rta->rta_len);
68 keylen -= RTA_ALIGN(rta->rta_len);
69
70 if (keylen < keys->enckeylen)
71 return -EINVAL;
72
73 keys->authkeylen = keylen - keys->enckeylen;
74 keys->authkey = key;
75 keys->enckey = key + keys->authkeylen;
76
77 return 0;
78}
79EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
80
81static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
82 unsigned int keylen)
83{
84 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
85 struct crypto_ahash *auth = ctx->auth;
86 struct crypto_skcipher *enc = ctx->enc;
87 struct crypto_authenc_keys keys;
88 int err = -EINVAL;
89
90 if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
91 goto badkey;
92
93 crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
94 crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
95 CRYPTO_TFM_REQ_MASK);
96 err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
97 crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &
98 CRYPTO_TFM_RES_MASK);
99
100 if (err)
101 goto out;
102
103 crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
104 crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
105 CRYPTO_TFM_REQ_MASK);
106 err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen);
107 crypto_aead_set_flags(authenc, crypto_skcipher_get_flags(enc) &
108 CRYPTO_TFM_RES_MASK);
109
110out:
111 return err;
112
113badkey:
114 crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
115 goto out;
116}
117
118static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
119{
120 struct aead_request *req = areq->data;
121 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
122 struct aead_instance *inst = aead_alg_instance(authenc);
123 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
124 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
125 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
126
127 if (err)
128 goto out;
129
130 scatterwalk_map_and_copy(ahreq->result, req->dst,
131 req->assoclen + req->cryptlen,
132 crypto_aead_authsize(authenc), 1);
133
134out:
135 aead_request_complete(req, err);
136}
137
138static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
139{
140 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
141 struct aead_instance *inst = aead_alg_instance(authenc);
142 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
143 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
144 struct crypto_ahash *auth = ctx->auth;
145 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
146 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
147 u8 *hash = areq_ctx->tail;
148 int err;
149
150 hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
151 crypto_ahash_alignmask(auth) + 1);
152
153 ahash_request_set_tfm(ahreq, auth);
154 ahash_request_set_crypt(ahreq, req->dst, hash,
155 req->assoclen + req->cryptlen);
156 ahash_request_set_callback(ahreq, flags,
157 authenc_geniv_ahash_done, req);
158
159 err = crypto_ahash_digest(ahreq);
160 if (err)
161 return err;
162
163 scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,
164 crypto_aead_authsize(authenc), 1);
165
166 return 0;
167}
168
169static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
170 int err)
171{
172 struct aead_request *areq = req->data;
173
174 if (err)
175 goto out;
176
177 err = crypto_authenc_genicv(areq, 0);
178
179out:
180 authenc_request_complete(areq, err);
181}
182
183static int crypto_authenc_copy_assoc(struct aead_request *req)
184{
185 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
186 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
187 SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
188
189 skcipher_request_set_tfm(skreq, ctx->null);
190 skcipher_request_set_callback(skreq, aead_request_flags(req),
191 NULL, NULL);
192 skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen,
193 NULL);
194
195 return crypto_skcipher_encrypt(skreq);
196}
197
198static int crypto_authenc_encrypt(struct aead_request *req)
199{
200 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
201 struct aead_instance *inst = aead_alg_instance(authenc);
202 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
203 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
204 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
205 struct crypto_skcipher *enc = ctx->enc;
206 unsigned int cryptlen = req->cryptlen;
207 struct skcipher_request *skreq = (void *)(areq_ctx->tail +
208 ictx->reqoff);
209 struct scatterlist *src, *dst;
210 int err;
211
212 src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
213 dst = src;
214
215 if (req->src != req->dst) {
216 err = crypto_authenc_copy_assoc(req);
217 if (err)
218 return err;
219
220 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
221 }
222
223 skcipher_request_set_tfm(skreq, enc);
224 skcipher_request_set_callback(skreq, aead_request_flags(req),
225 crypto_authenc_encrypt_done, req);
226 skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
227
228 err = crypto_skcipher_encrypt(skreq);
229 if (err)
230 return err;
231
232 return crypto_authenc_genicv(req, aead_request_flags(req));
233}
234
235static int crypto_authenc_decrypt_tail(struct aead_request *req,
236 unsigned int flags)
237{
238 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
239 struct aead_instance *inst = aead_alg_instance(authenc);
240 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
241 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
242 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
243 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
244 struct skcipher_request *skreq = (void *)(areq_ctx->tail +
245 ictx->reqoff);
246 unsigned int authsize = crypto_aead_authsize(authenc);
247 u8 *ihash = ahreq->result + authsize;
248 struct scatterlist *src, *dst;
249
250 scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0);
251
252 if (crypto_memneq(ihash, ahreq->result, authsize))
253 return -EBADMSG;
254
255 src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
256 dst = src;
257
258 if (req->src != req->dst)
259 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
260
261 skcipher_request_set_tfm(skreq, ctx->enc);
262 skcipher_request_set_callback(skreq, aead_request_flags(req),
263 req->base.complete, req->base.data);
264 skcipher_request_set_crypt(skreq, src, dst,
265 req->cryptlen - authsize, req->iv);
266
267 return crypto_skcipher_decrypt(skreq);
268}
269
270static void authenc_verify_ahash_done(struct crypto_async_request *areq,
271 int err)
272{
273 struct aead_request *req = areq->data;
274
275 if (err)
276 goto out;
277
278 err = crypto_authenc_decrypt_tail(req, 0);
279
280out:
281 authenc_request_complete(req, err);
282}
283
284static int crypto_authenc_decrypt(struct aead_request *req)
285{
286 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
287 unsigned int authsize = crypto_aead_authsize(authenc);
288 struct aead_instance *inst = aead_alg_instance(authenc);
289 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
290 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
291 struct crypto_ahash *auth = ctx->auth;
292 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
293 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
294 u8 *hash = areq_ctx->tail;
295 int err;
296
297 hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
298 crypto_ahash_alignmask(auth) + 1);
299
300 ahash_request_set_tfm(ahreq, auth);
301 ahash_request_set_crypt(ahreq, req->src, hash,
302 req->assoclen + req->cryptlen - authsize);
303 ahash_request_set_callback(ahreq, aead_request_flags(req),
304 authenc_verify_ahash_done, req);
305
306 err = crypto_ahash_digest(ahreq);
307 if (err)
308 return err;
309
310 return crypto_authenc_decrypt_tail(req, aead_request_flags(req));
311}
312
313static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
314{
315 struct aead_instance *inst = aead_alg_instance(tfm);
316 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
317 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
318 struct crypto_ahash *auth;
319 struct crypto_skcipher *enc;
320 struct crypto_skcipher *null;
321 int err;
322
323 auth = crypto_spawn_ahash(&ictx->auth);
324 if (IS_ERR(auth))
325 return PTR_ERR(auth);
326
327 enc = crypto_spawn_skcipher(&ictx->enc);
328 err = PTR_ERR(enc);
329 if (IS_ERR(enc))
330 goto err_free_ahash;
331
332 null = crypto_get_default_null_skcipher();
333 err = PTR_ERR(null);
334 if (IS_ERR(null))
335 goto err_free_skcipher;
336
337 ctx->auth = auth;
338 ctx->enc = enc;
339 ctx->null = null;
340
341 crypto_aead_set_reqsize(
342 tfm,
343 sizeof(struct authenc_request_ctx) +
344 ictx->reqoff +
345 max_t(unsigned int,
346 crypto_ahash_reqsize(auth) +
347 sizeof(struct ahash_request),
348 sizeof(struct skcipher_request) +
349 crypto_skcipher_reqsize(enc)));
350
351 return 0;
352
353err_free_skcipher:
354 crypto_free_skcipher(enc);
355err_free_ahash:
356 crypto_free_ahash(auth);
357 return err;
358}
359
360static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
361{
362 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
363
364 crypto_free_ahash(ctx->auth);
365 crypto_free_skcipher(ctx->enc);
366 crypto_put_default_null_skcipher();
367}
368
369static void crypto_authenc_free(struct aead_instance *inst)
370{
371 struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);
372
373 crypto_drop_skcipher(&ctx->enc);
374 crypto_drop_ahash(&ctx->auth);
375 kfree(inst);
376}
377
378static int crypto_authenc_create(struct crypto_template *tmpl,
379 struct rtattr **tb)
380{
381 struct crypto_attr_type *algt;
382 struct aead_instance *inst;
383 struct hash_alg_common *auth;
384 struct crypto_alg *auth_base;
385 struct skcipher_alg *enc;
386 struct authenc_instance_ctx *ctx;
387 const char *enc_name;
388 int err;
389
390 algt = crypto_get_attr_type(tb);
391 if (IS_ERR(algt))
392 return PTR_ERR(algt);
393
394 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
395 return -EINVAL;
396
397 auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
398 CRYPTO_ALG_TYPE_AHASH_MASK |
399 crypto_requires_sync(algt->type, algt->mask));
400 if (IS_ERR(auth))
401 return PTR_ERR(auth);
402
403 auth_base = &auth->base;
404
405 enc_name = crypto_attr_alg_name(tb[2]);
406 err = PTR_ERR(enc_name);
407 if (IS_ERR(enc_name))
408 goto out_put_auth;
409
410 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
411 err = -ENOMEM;
412 if (!inst)
413 goto out_put_auth;
414
415 ctx = aead_instance_ctx(inst);
416
417 err = crypto_init_ahash_spawn(&ctx->auth, auth,
418 aead_crypto_instance(inst));
419 if (err)
420 goto err_free_inst;
421
422 crypto_set_skcipher_spawn(&ctx->enc, aead_crypto_instance(inst));
423 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
424 crypto_requires_sync(algt->type,
425 algt->mask));
426 if (err)
427 goto err_drop_auth;
428
429 enc = crypto_spawn_skcipher_alg(&ctx->enc);
430
431 ctx->reqoff = ALIGN(2 * auth->digestsize + auth_base->cra_alignmask,
432 auth_base->cra_alignmask + 1);
433
434 err = -ENAMETOOLONG;
435 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
436 "authenc(%s,%s)", auth_base->cra_name,
437 enc->base.cra_name) >=
438 CRYPTO_MAX_ALG_NAME)
439 goto err_drop_enc;
440
441 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
442 "authenc(%s,%s)", auth_base->cra_driver_name,
443 enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
444 goto err_drop_enc;
445
446 inst->alg.base.cra_flags = (auth_base->cra_flags |
447 enc->base.cra_flags) & CRYPTO_ALG_ASYNC;
448 inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
449 auth_base->cra_priority;
450 inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
451 inst->alg.base.cra_alignmask = auth_base->cra_alignmask |
452 enc->base.cra_alignmask;
453 inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
454
455 inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc);
456 inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc);
457 inst->alg.maxauthsize = auth->digestsize;
458
459 inst->alg.init = crypto_authenc_init_tfm;
460 inst->alg.exit = crypto_authenc_exit_tfm;
461
462 inst->alg.setkey = crypto_authenc_setkey;
463 inst->alg.encrypt = crypto_authenc_encrypt;
464 inst->alg.decrypt = crypto_authenc_decrypt;
465
466 inst->free = crypto_authenc_free;
467
468 err = aead_register_instance(tmpl, inst);
469 if (err)
470 goto err_drop_enc;
471
472out:
473 crypto_mod_put(auth_base);
474 return err;
475
476err_drop_enc:
477 crypto_drop_skcipher(&ctx->enc);
478err_drop_auth:
479 crypto_drop_ahash(&ctx->auth);
480err_free_inst:
481 kfree(inst);
482out_put_auth:
483 goto out;
484}
485
486static struct crypto_template crypto_authenc_tmpl = {
487 .name = "authenc",
488 .create = crypto_authenc_create,
489 .module = THIS_MODULE,
490};
491
492static int __init crypto_authenc_module_init(void)
493{
494 return crypto_register_template(&crypto_authenc_tmpl);
495}
496
497static void __exit crypto_authenc_module_exit(void)
498{
499 crypto_unregister_template(&crypto_authenc_tmpl);
500}
501
502module_init(crypto_authenc_module_init);
503module_exit(crypto_authenc_module_exit);
504
505MODULE_LICENSE("GPL");
506MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
507MODULE_ALIAS_CRYPTO("authenc");
508
