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