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13#include <crypto/aead.h>
14#include <crypto/internal/skcipher.h>
15#include <crypto/authenc.h>
16#include <crypto/scatterwalk.h>
17#include <linux/err.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/rtnetlink.h>
22#include <linux/slab.h>
23#include <linux/spinlock.h>
24
25struct authenc_instance_ctx {
26 struct crypto_spawn auth;
27 struct crypto_skcipher_spawn enc;
28};
29
30struct crypto_authenc_ctx {
31 spinlock_t auth_lock;
32 struct crypto_hash *auth;
33 struct crypto_ablkcipher *enc;
34};
35
36static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
37 unsigned int keylen)
38{
39 unsigned int authkeylen;
40 unsigned int enckeylen;
41 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
42 struct crypto_hash *auth = ctx->auth;
43 struct crypto_ablkcipher *enc = ctx->enc;
44 struct rtattr *rta = (void *)key;
45 struct crypto_authenc_key_param *param;
46 int err = -EINVAL;
47
48 if (!RTA_OK(rta, keylen))
49 goto badkey;
50 if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
51 goto badkey;
52 if (RTA_PAYLOAD(rta) < sizeof(*param))
53 goto badkey;
54
55 param = RTA_DATA(rta);
56 enckeylen = be32_to_cpu(param->enckeylen);
57
58 key += RTA_ALIGN(rta->rta_len);
59 keylen -= RTA_ALIGN(rta->rta_len);
60
61 if (keylen < enckeylen)
62 goto badkey;
63
64 authkeylen = keylen - enckeylen;
65
66 crypto_hash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
67 crypto_hash_set_flags(auth, crypto_aead_get_flags(authenc) &
68 CRYPTO_TFM_REQ_MASK);
69 err = crypto_hash_setkey(auth, key, authkeylen);
70 crypto_aead_set_flags(authenc, crypto_hash_get_flags(auth) &
71 CRYPTO_TFM_RES_MASK);
72
73 if (err)
74 goto out;
75
76 crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
77 crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
78 CRYPTO_TFM_REQ_MASK);
79 err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
80 crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
81 CRYPTO_TFM_RES_MASK);
82
83out:
84 return err;
85
86badkey:
87 crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
88 goto out;
89}
90
91static void authenc_chain(struct scatterlist *head, struct scatterlist *sg,
92 int chain)
93{
94 if (chain) {
95 head->length += sg->length;
96 sg = scatterwalk_sg_next(sg);
97 }
98
99 if (sg)
100 scatterwalk_sg_chain(head, 2, sg);
101 else
102 sg_mark_end(head);
103}
104
105static u8 *crypto_authenc_hash(struct aead_request *req, unsigned int flags,
106 struct scatterlist *cipher,
107 unsigned int cryptlen)
108{
109 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
110 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
111 struct crypto_hash *auth = ctx->auth;
112 struct hash_desc desc = {
113 .tfm = auth,
114 .flags = aead_request_flags(req) & flags,
115 };
116 u8 *hash = aead_request_ctx(req);
117 int err;
118
119 hash = (u8 *)ALIGN((unsigned long)hash + crypto_hash_alignmask(auth),
120 crypto_hash_alignmask(auth) + 1);
121
122 spin_lock_bh(&ctx->auth_lock);
123 err = crypto_hash_init(&desc);
124 if (err)
125 goto auth_unlock;
126
127 err = crypto_hash_update(&desc, req->assoc, req->assoclen);
128 if (err)
129 goto auth_unlock;
130
131 err = crypto_hash_update(&desc, cipher, cryptlen);
132 if (err)
133 goto auth_unlock;
134
135 err = crypto_hash_final(&desc, hash);
136auth_unlock:
137 spin_unlock_bh(&ctx->auth_lock);
138
139 if (err)
140 return ERR_PTR(err);
141
142 return hash;
143}
144
145static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
146 unsigned int flags)
147{
148 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
149 struct scatterlist *dst = req->dst;
150 struct scatterlist cipher[2];
151 struct page *dstp;
152 unsigned int ivsize = crypto_aead_ivsize(authenc);
153 unsigned int cryptlen;
154 u8 *vdst;
155 u8 *hash;
156
157 dstp = sg_page(dst);
158 vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
159
160 sg_init_table(cipher, 2);
161 sg_set_buf(cipher, iv, ivsize);
162 authenc_chain(cipher, dst, vdst == iv + ivsize);
163
164 cryptlen = req->cryptlen + ivsize;
165 hash = crypto_authenc_hash(req, flags, cipher, cryptlen);
166 if (IS_ERR(hash))
167 return PTR_ERR(hash);
168
169 scatterwalk_map_and_copy(hash, cipher, cryptlen,
170 crypto_aead_authsize(authenc), 1);
171 return 0;
172}
173
174static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
175 int err)
176{
177 struct aead_request *areq = req->data;
178
179 if (!err) {
180 struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
181 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
182 struct ablkcipher_request *abreq = aead_request_ctx(areq);
183 u8 *iv = (u8 *)(abreq + 1) +
184 crypto_ablkcipher_reqsize(ctx->enc);
185
186 err = crypto_authenc_genicv(areq, iv, 0);
187 }
188
189 aead_request_complete(areq, err);
190}
191
192static int crypto_authenc_encrypt(struct aead_request *req)
193{
194 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
195 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
196 struct ablkcipher_request *abreq = aead_request_ctx(req);
197 struct crypto_ablkcipher *enc = ctx->enc;
198 struct scatterlist *dst = req->dst;
199 unsigned int cryptlen = req->cryptlen;
200 u8 *iv = (u8 *)(abreq + 1) + crypto_ablkcipher_reqsize(enc);
201 int err;
202
203 ablkcipher_request_set_tfm(abreq, enc);
204 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
205 crypto_authenc_encrypt_done, req);
206 ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
207
208 memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
209
210 err = crypto_ablkcipher_encrypt(abreq);
211 if (err)
212 return err;
213
214 return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
215}
216
217static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
218 int err)
219{
220 struct aead_request *areq = req->data;
221
222 if (!err) {
223 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
224
225 err = crypto_authenc_genicv(areq, greq->giv, 0);
226 }
227
228 aead_request_complete(areq, err);
229}
230
231static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
232{
233 struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
234 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
235 struct aead_request *areq = &req->areq;
236 struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
237 u8 *iv = req->giv;
238 int err;
239
240 skcipher_givcrypt_set_tfm(greq, ctx->enc);
241 skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
242 crypto_authenc_givencrypt_done, areq);
243 skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
244 areq->iv);
245 skcipher_givcrypt_set_giv(greq, iv, req->seq);
246
247 err = crypto_skcipher_givencrypt(greq);
248 if (err)
249 return err;
250
251 return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
252}
253
254static int crypto_authenc_verify(struct aead_request *req,
255 struct scatterlist *cipher,
256 unsigned int cryptlen)
257{
258 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
259 u8 *ohash;
260 u8 *ihash;
261 unsigned int authsize;
262
263 ohash = crypto_authenc_hash(req, CRYPTO_TFM_REQ_MAY_SLEEP, cipher,
264 cryptlen);
265 if (IS_ERR(ohash))
266 return PTR_ERR(ohash);
267
268 authsize = crypto_aead_authsize(authenc);
269 ihash = ohash + authsize;
270 scatterwalk_map_and_copy(ihash, cipher, cryptlen, authsize, 0);
271 return memcmp(ihash, ohash, authsize) ? -EBADMSG: 0;
272}
273
274static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
275 unsigned int cryptlen)
276{
277 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
278 struct scatterlist *src = req->src;
279 struct scatterlist cipher[2];
280 struct page *srcp;
281 unsigned int ivsize = crypto_aead_ivsize(authenc);
282 u8 *vsrc;
283
284 srcp = sg_page(src);
285 vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
286
287 sg_init_table(cipher, 2);
288 sg_set_buf(cipher, iv, ivsize);
289 authenc_chain(cipher, src, vsrc == iv + ivsize);
290
291 return crypto_authenc_verify(req, cipher, cryptlen + ivsize);
292}
293
294static int crypto_authenc_decrypt(struct aead_request *req)
295{
296 struct crypto_aead *authenc = crypto_aead_reqtfm(req);
297 struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
298 struct ablkcipher_request *abreq = aead_request_ctx(req);
299 unsigned int cryptlen = req->cryptlen;
300 unsigned int authsize = crypto_aead_authsize(authenc);
301 u8 *iv = req->iv;
302 int err;
303
304 if (cryptlen < authsize)
305 return -EINVAL;
306 cryptlen -= authsize;
307
308 err = crypto_authenc_iverify(req, iv, cryptlen);
309 if (err)
310 return err;
311
312 ablkcipher_request_set_tfm(abreq, ctx->enc);
313 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
314 req->base.complete, req->base.data);
315 ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
316
317 return crypto_ablkcipher_decrypt(abreq);
318}
319
320static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
321{
322 struct crypto_instance *inst = (void *)tfm->__crt_alg;
323 struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
324 struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
325 struct crypto_hash *auth;
326 struct crypto_ablkcipher *enc;
327 int err;
328
329 auth = crypto_spawn_hash(&ictx->auth);
330 if (IS_ERR(auth))
331 return PTR_ERR(auth);
332
333 enc = crypto_spawn_skcipher(&ictx->enc);
334 err = PTR_ERR(enc);
335 if (IS_ERR(enc))
336 goto err_free_hash;
337
338 ctx->auth = auth;
339 ctx->enc = enc;
340 tfm->crt_aead.reqsize = max_t(unsigned int,
341 (crypto_hash_alignmask(auth) &
342 ~(crypto_tfm_ctx_alignment() - 1)) +
343 crypto_hash_digestsize(auth) * 2,
344 sizeof(struct skcipher_givcrypt_request) +
345 crypto_ablkcipher_reqsize(enc) +
346 crypto_ablkcipher_ivsize(enc));
347
348 spin_lock_init(&ctx->auth_lock);
349
350 return 0;
351
352err_free_hash:
353 crypto_free_hash(auth);
354 return err;
355}
356
357static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
358{
359 struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
360
361 crypto_free_hash(ctx->auth);
362 crypto_free_ablkcipher(ctx->enc);
363}
364
365static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
366{
367 struct crypto_attr_type *algt;
368 struct crypto_instance *inst;
369 struct crypto_alg *auth;
370 struct crypto_alg *enc;
371 struct authenc_instance_ctx *ctx;
372 const char *enc_name;
373 int err;
374
375 algt = crypto_get_attr_type(tb);
376 err = PTR_ERR(algt);
377 if (IS_ERR(algt))
378 return ERR_PTR(err);
379
380 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
381 return ERR_PTR(-EINVAL);
382
383 auth = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
384 CRYPTO_ALG_TYPE_HASH_MASK);
385 if (IS_ERR(auth))
386 return ERR_PTR(PTR_ERR(auth));
387
388 enc_name = crypto_attr_alg_name(tb[2]);
389 err = PTR_ERR(enc_name);
390 if (IS_ERR(enc_name))
391 goto out_put_auth;
392
393 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
394 err = -ENOMEM;
395 if (!inst)
396 goto out_put_auth;
397
398 ctx = crypto_instance_ctx(inst);
399
400 err = crypto_init_spawn(&ctx->auth, auth, inst, CRYPTO_ALG_TYPE_MASK);
401 if (err)
402 goto err_free_inst;
403
404 crypto_set_skcipher_spawn(&ctx->enc, inst);
405 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
406 crypto_requires_sync(algt->type,
407 algt->mask));
408 if (err)
409 goto err_drop_auth;
410
411 enc = crypto_skcipher_spawn_alg(&ctx->enc);
412
413 err = -ENAMETOOLONG;
414 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
415 "authenc(%s,%s)", auth->cra_name, enc->cra_name) >=
416 CRYPTO_MAX_ALG_NAME)
417 goto err_drop_enc;
418
419 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
420 "authenc(%s,%s)", auth->cra_driver_name,
421 enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
422 goto err_drop_enc;
423
424 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
425 inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
426 inst->alg.cra_priority = enc->cra_priority * 10 + auth->cra_priority;
427 inst->alg.cra_blocksize = enc->cra_blocksize;
428 inst->alg.cra_alignmask = auth->cra_alignmask | enc->cra_alignmask;
429 inst->alg.cra_type = &crypto_aead_type;
430
431 inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
432 inst->alg.cra_aead.maxauthsize = auth->cra_type == &crypto_hash_type ?
433 auth->cra_hash.digestsize :
434 auth->cra_digest.dia_digestsize;
435
436 inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
437
438 inst->alg.cra_init = crypto_authenc_init_tfm;
439 inst->alg.cra_exit = crypto_authenc_exit_tfm;
440
441 inst->alg.cra_aead.setkey = crypto_authenc_setkey;
442 inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
443 inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
444 inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
445
446out:
447 crypto_mod_put(auth);
448 return inst;
449
450err_drop_enc:
451 crypto_drop_skcipher(&ctx->enc);
452err_drop_auth:
453 crypto_drop_spawn(&ctx->auth);
454err_free_inst:
455 kfree(inst);
456out_put_auth:
457 inst = ERR_PTR(err);
458 goto out;
459}
460
461static void crypto_authenc_free(struct crypto_instance *inst)
462{
463 struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
464
465 crypto_drop_skcipher(&ctx->enc);
466 crypto_drop_spawn(&ctx->auth);
467 kfree(inst);
468}
469
470static struct crypto_template crypto_authenc_tmpl = {
471 .name = "authenc",
472 .alloc = crypto_authenc_alloc,
473 .free = crypto_authenc_free,
474 .module = THIS_MODULE,
475};
476
477static int __init crypto_authenc_module_init(void)
478{
479 return crypto_register_template(&crypto_authenc_tmpl);
480}
481
482static void __exit crypto_authenc_module_exit(void)
483{
484 crypto_unregister_template(&crypto_authenc_tmpl);
485}
486
487module_init(crypto_authenc_module_init);
488module_exit(crypto_authenc_module_exit);
489
490MODULE_LICENSE("GPL");
491MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
492
