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8#include <crypto/internal/aead.h>
9#include <crypto/internal/hash.h>
10#include <crypto/internal/skcipher.h>
11#include <crypto/authenc.h>
12#include <crypto/null.h>
13#include <crypto/scatterwalk.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/rtnetlink.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21
22struct authenc_instance_ctx {
23 struct crypto_ahash_spawn auth;
24 struct crypto_skcipher_spawn enc;
25 unsigned int reqoff;
26};
27
28struct crypto_authenc_ctx {
29 struct crypto_ahash *auth;
30 struct crypto_skcipher *enc;
31 struct crypto_sync_skcipher *null;
32};
33
34struct authenc_request_ctx {
35 struct scatterlist src[2];
36 struct scatterlist dst[2];
37 char tail[];
38};
39
40static void authenc_request_complete(struct aead_request *req, int err)
41{
42 if (err != -EINPROGRESS)
43 aead_request_complete(req, err);
44}
45
46int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
47 unsigned int keylen)
48{
49 struct rtattr *rta = (struct rtattr *)key;
50 struct crypto_authenc_key_param *param;
51
52 if (!RTA_OK(rta, keylen))
53 return -EINVAL;
54 if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
55 return -EINVAL;
56
57
58
59
60
61
62
63 if (RTA_PAYLOAD(rta) != sizeof(*param))
64 return -EINVAL;
65 BUILD_BUG_ON(sizeof(*param) % RTA_ALIGNTO);
66
67 param = RTA_DATA(rta);
68 keys->enckeylen = be32_to_cpu(param->enckeylen);
69
70 key += rta->rta_len;
71 keylen -= rta->rta_len;
72
73 if (keylen < keys->enckeylen)
74 return -EINVAL;
75
76 keys->authkeylen = keylen - keys->enckeylen;
77 keys->authkey = key;
78 keys->enckey = key + keys->authkeylen;
79
80 return 0;
81}
82EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
83
84static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
85 unsigned int keylen)
86{
87 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
88 struct crypto_ahash *auth = ctx->auth;
89 struct crypto_skcipher *enc = ctx->enc;
90 struct crypto_authenc_keys keys;
91 int err = -EINVAL;
92
93 if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
94 goto out;
95
96 crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
97 crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &
98 CRYPTO_TFM_REQ_MASK);
99 err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);
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);
107out:
108 memzero_explicit(&keys, sizeof(keys));
109 return err;
110}
111
112static void authenc_geniv_ahash_done(struct crypto_async_request *areq, int err)
113{
114 struct aead_request *req = areq->data;
115 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
116 struct aead_instance *inst = aead_alg_instance(authenc);
117 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
118 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
119 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
120
121 if (err)
122 goto out;
123
124 scatterwalk_map_and_copy(ahreq->result, req->dst,
125 req->assoclen + req->cryptlen,
126 crypto_aead_authsize(authenc), 1);
127
128out:
129 aead_request_complete(req, err);
130}
131
132static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
133{
134 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
135 struct aead_instance *inst = aead_alg_instance(authenc);
136 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
137 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
138 struct crypto_ahash *auth = ctx->auth;
139 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
140 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
141 u8 *hash = areq_ctx->tail;
142 int err;
143
144 hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
145 crypto_ahash_alignmask(auth) + 1);
146
147 ahash_request_set_tfm(ahreq, auth);
148 ahash_request_set_crypt(ahreq, req->dst, hash,
149 req->assoclen + req->cryptlen);
150 ahash_request_set_callback(ahreq, flags,
151 authenc_geniv_ahash_done, req);
152
153 err = crypto_ahash_digest(ahreq);
154 if (err)
155 return err;
156
157 scatterwalk_map_and_copy(hash, req->dst, req->assoclen + req->cryptlen,
158 crypto_aead_authsize(authenc), 1);
159
160 return 0;
161}
162
163static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
164 int err)
165{
166 struct aead_request *areq = req->data;
167
168 if (err)
169 goto out;
170
171 err = crypto_authenc_genicv(areq, 0);
172
173out:
174 authenc_request_complete(areq, err);
175}
176
177static int crypto_authenc_copy_assoc(struct aead_request *req)
178{
179 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
180 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
181 SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
182
183 skcipher_request_set_sync_tfm(skreq, ctx->null);
184 skcipher_request_set_callback(skreq, aead_request_flags(req),
185 NULL, NULL);
186 skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen,
187 NULL);
188
189 return crypto_skcipher_encrypt(skreq);
190}
191
192static int crypto_authenc_encrypt(struct aead_request *req)
193{
194 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
195 struct aead_instance *inst = aead_alg_instance(authenc);
196 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
197 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
198 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
199 struct crypto_skcipher *enc = ctx->enc;
200 unsigned int cryptlen = req->cryptlen;
201 struct skcipher_request *skreq = (void *)(areq_ctx->tail +
202 ictx->reqoff);
203 struct scatterlist *src, *dst;
204 int err;
205
206 src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
207 dst = src;
208
209 if (req->src != req->dst) {
210 err = crypto_authenc_copy_assoc(req);
211 if (err)
212 return err;
213
214 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
215 }
216
217 skcipher_request_set_tfm(skreq, enc);
218 skcipher_request_set_callback(skreq, aead_request_flags(req),
219 crypto_authenc_encrypt_done, req);
220 skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
221
222 err = crypto_skcipher_encrypt(skreq);
223 if (err)
224 return err;
225
226 return crypto_authenc_genicv(req, aead_request_flags(req));
227}
228
229static int crypto_authenc_decrypt_tail(struct aead_request *req,
230 unsigned int flags)
231{
232 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
233 struct aead_instance *inst = aead_alg_instance(authenc);
234 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
235 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
236 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
237 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
238 struct skcipher_request *skreq = (void *)(areq_ctx->tail +
239 ictx->reqoff);
240 unsigned int authsize = crypto_aead_authsize(authenc);
241 u8 *ihash = ahreq->result + authsize;
242 struct scatterlist *src, *dst;
243
244 scatterwalk_map_and_copy(ihash, req->src, ahreq->nbytes, authsize, 0);
245
246 if (crypto_memneq(ihash, ahreq->result, authsize))
247 return -EBADMSG;
248
249 src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
250 dst = src;
251
252 if (req->src != req->dst)
253 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
254
255 skcipher_request_set_tfm(skreq, ctx->enc);
256 skcipher_request_set_callback(skreq, aead_request_flags(req),
257 req->base.complete, req->base.data);
258 skcipher_request_set_crypt(skreq, src, dst,
259 req->cryptlen - authsize, req->iv);
260
261 return crypto_skcipher_decrypt(skreq);
262}
263
264static void authenc_verify_ahash_done(struct crypto_async_request *areq,
265 int err)
266{
267 struct aead_request *req = areq->data;
268
269 if (err)
270 goto out;
271
272 err = crypto_authenc_decrypt_tail(req, 0);
273
274out:
275 authenc_request_complete(req, err);
276}
277
278static int crypto_authenc_decrypt(struct aead_request *req)
279{
280 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
281 unsigned int authsize = crypto_aead_authsize(authenc);
282 struct aead_instance *inst = aead_alg_instance(authenc);
283 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
284 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
285 struct crypto_ahash *auth = ctx->auth;
286 struct authenc_request_ctx *areq_ctx = aead_request_ctx(req);
287 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ictx->reqoff);
288 u8 *hash = areq_ctx->tail;
289 int err;
290
291 hash = (u8 *)ALIGN((unsigned long)hash + crypto_ahash_alignmask(auth),
292 crypto_ahash_alignmask(auth) + 1);
293
294 ahash_request_set_tfm(ahreq, auth);
295 ahash_request_set_crypt(ahreq, req->src, hash,
296 req->assoclen + req->cryptlen - authsize);
297 ahash_request_set_callback(ahreq, aead_request_flags(req),
298 authenc_verify_ahash_done, req);
299
300 err = crypto_ahash_digest(ahreq);
301 if (err)
302 return err;
303
304 return crypto_authenc_decrypt_tail(req, aead_request_flags(req));
305}
306
307static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
308{
309 struct aead_instance *inst = aead_alg_instance(tfm);
310 struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
311 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
312 struct crypto_ahash *auth;
313 struct crypto_skcipher *enc;
314 struct crypto_sync_skcipher *null;
315 int err;
316
317 auth = crypto_spawn_ahash(&ictx->auth);
318 if (IS_ERR(auth))
319 return PTR_ERR(auth);
320
321 enc = crypto_spawn_skcipher(&ictx->enc);
322 err = PTR_ERR(enc);
323 if (IS_ERR(enc))
324 goto err_free_ahash;
325
326 null = crypto_get_default_null_skcipher();
327 err = PTR_ERR(null);
328 if (IS_ERR(null))
329 goto err_free_skcipher;
330
331 ctx->auth = auth;
332 ctx->enc = enc;
333 ctx->null = null;
334
335 crypto_aead_set_reqsize(
336 tfm,
337 sizeof(struct authenc_request_ctx) +
338 ictx->reqoff +
339 max_t(unsigned int,
340 crypto_ahash_reqsize(auth) +
341 sizeof(struct ahash_request),
342 sizeof(struct skcipher_request) +
343 crypto_skcipher_reqsize(enc)));
344
345 return 0;
346
347err_free_skcipher:
348 crypto_free_skcipher(enc);
349err_free_ahash:
350 crypto_free_ahash(auth);
351 return err;
352}
353
354static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
355{
356 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
357
358 crypto_free_ahash(ctx->auth);
359 crypto_free_skcipher(ctx->enc);
360 crypto_put_default_null_skcipher();
361}
362
363static void crypto_authenc_free(struct aead_instance *inst)
364{
365 struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);
366
367 crypto_drop_skcipher(&ctx->enc);
368 crypto_drop_ahash(&ctx->auth);
369 kfree(inst);
370}
371
372static int crypto_authenc_create(struct crypto_template *tmpl,
373 struct rtattr **tb)
374{
375 u32 mask;
376 struct aead_instance *inst;
377 struct authenc_instance_ctx *ctx;
378 struct hash_alg_common *auth;
379 struct crypto_alg *auth_base;
380 struct skcipher_alg *enc;
381 int err;
382
383 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
384 if (err)
385 return err;
386
387 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
388 if (!inst)
389 return -ENOMEM;
390 ctx = aead_instance_ctx(inst);
391
392 err = crypto_grab_ahash(&ctx->auth, aead_crypto_instance(inst),
393 crypto_attr_alg_name(tb[1]), 0, mask);
394 if (err)
395 goto err_free_inst;
396 auth = crypto_spawn_ahash_alg(&ctx->auth);
397 auth_base = &auth->base;
398
399 err = crypto_grab_skcipher(&ctx->enc, aead_crypto_instance(inst),
400 crypto_attr_alg_name(tb[2]), 0, mask);
401 if (err)
402 goto err_free_inst;
403 enc = crypto_spawn_skcipher_alg(&ctx->enc);
404
405 ctx->reqoff = ALIGN(2 * auth->digestsize + auth_base->cra_alignmask,
406 auth_base->cra_alignmask + 1);
407
408 err = -ENAMETOOLONG;
409 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
410 "authenc(%s,%s)", auth_base->cra_name,
411 enc->base.cra_name) >=
412 CRYPTO_MAX_ALG_NAME)
413 goto err_free_inst;
414
415 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
416 "authenc(%s,%s)", auth_base->cra_driver_name,
417 enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
418 goto err_free_inst;
419
420 inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
421 auth_base->cra_priority;
422 inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
423 inst->alg.base.cra_alignmask = auth_base->cra_alignmask |
424 enc->base.cra_alignmask;
425 inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
426
427 inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc);
428 inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc);
429 inst->alg.maxauthsize = auth->digestsize;
430
431 inst->alg.init = crypto_authenc_init_tfm;
432 inst->alg.exit = crypto_authenc_exit_tfm;
433
434 inst->alg.setkey = crypto_authenc_setkey;
435 inst->alg.encrypt = crypto_authenc_encrypt;
436 inst->alg.decrypt = crypto_authenc_decrypt;
437
438 inst->free = crypto_authenc_free;
439
440 err = aead_register_instance(tmpl, inst);
441 if (err) {
442err_free_inst:
443 crypto_authenc_free(inst);
444 }
445 return err;
446}
447
448static struct crypto_template crypto_authenc_tmpl = {
449 .name = "authenc",
450 .create = crypto_authenc_create,
451 .module = THIS_MODULE,
452};
453
454static int __init crypto_authenc_module_init(void)
455{
456 return crypto_register_template(&crypto_authenc_tmpl);
457}
458
459static void __exit crypto_authenc_module_exit(void)
460{
461 crypto_unregister_template(&crypto_authenc_tmpl);
462}
463
464subsys_initcall(crypto_authenc_module_init);
465module_exit(crypto_authenc_module_exit);
466
467MODULE_LICENSE("GPL");
468MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
469MODULE_ALIAS_CRYPTO("authenc");
470
