Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/crypto/authenc.c

  1 /*
  2  * Authenc: Simple AEAD wrapper for IPsec
  3  *
  4  * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
  5  *
  6  * This program is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License as published by the Free
  8  * Software Foundation; either version 2 of the License, or (at your option)
  9  * any later version.
 10  *
 11  */
 12 
 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 
 27 struct authenc_instance_ctx {
 28         struct crypto_ahash_spawn auth;
 29         struct crypto_skcipher_spawn enc;
 30         unsigned int reqoff;
 31 };
 32 
 33 struct crypto_authenc_ctx {
 34         struct crypto_ahash *auth;
 35         struct crypto_skcipher *enc;
 36         struct crypto_skcipher *null;
 37 };
 38 
 39 struct authenc_request_ctx {
 40         struct scatterlist src[2];
 41         struct scatterlist dst[2];
 42         char tail[];
 43 };
 44 
 45 static void authenc_request_complete(struct aead_request *req, int err)
 46 {
 47         if (err != -EINPROGRESS)
 48                 aead_request_complete(req, err);
 49 }
 50 
 51 int 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 }
 79 EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);
 80 
 81 static 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 
110 out:
111         return err;
112 
113 badkey:
114         crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
115         goto out;
116 }
117 
118 static 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 
134 out:
135         aead_request_complete(req, err);
136 }
137 
138 static 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 
169 static 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 
179 out:
180         authenc_request_complete(areq, err);
181 }
182 
183 static 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 
198 static 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 
235 static 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 
270 static 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 
280 out:
281         authenc_request_complete(req, err);
282 }
283 
284 static 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 
313 static 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_skcipher2();
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 
353 err_free_skcipher:
354         crypto_free_skcipher(enc);
355 err_free_ahash:
356         crypto_free_ahash(auth);
357         return err;
358 }
359 
360 static 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_skcipher2();
367 }
368 
369 static 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 
378 static 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 
472 out:
473         crypto_mod_put(auth_base);
474         return err;
475 
476 err_drop_enc:
477         crypto_drop_skcipher(&ctx->enc);
478 err_drop_auth:
479         crypto_drop_ahash(&ctx->auth);
480 err_free_inst:
481         kfree(inst);
482 out_put_auth:
483         goto out;
484 }
485 
486 static struct crypto_template crypto_authenc_tmpl = {
487         .name = "authenc",
488         .create = crypto_authenc_create,
489         .module = THIS_MODULE,
490 };
491 
492 static int __init crypto_authenc_module_init(void)
493 {
494         return crypto_register_template(&crypto_authenc_tmpl);
495 }
496 
497 static void __exit crypto_authenc_module_exit(void)
498 {
499         crypto_unregister_template(&crypto_authenc_tmpl);
500 }
501 
502 module_init(crypto_authenc_module_init);
503 module_exit(crypto_authenc_module_exit);
504 
505 MODULE_LICENSE("GPL");
506 MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
507 MODULE_ALIAS_CRYPTO("authenc");
508 

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