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Commit | Line | Data |
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0a270321 HX |
1 | /* |
2 | * seqiv: Sequence Number IV Generator | |
3 | * | |
4 | * This generator generates an IV based on a sequence number by xoring it | |
5 | * with a salt. This algorithm is mainly useful for CTR and similar modes. | |
6 | * | |
7 | * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify it | |
10 | * under the terms of the GNU General Public License as published by the Free | |
11 | * Software Foundation; either version 2 of the License, or (at your option) | |
12 | * any later version. | |
13 | * | |
14 | */ | |
15 | ||
661cfd0e | 16 | #include <crypto/internal/geniv.h> |
0a270321 | 17 | #include <crypto/internal/skcipher.h> |
856e3f40 | 18 | #include <crypto/null.h> |
a0f000ec | 19 | #include <crypto/rng.h> |
856e3f40 | 20 | #include <crypto/scatterwalk.h> |
0a270321 HX |
21 | #include <linux/err.h> |
22 | #include <linux/init.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/module.h> | |
5a0e3ad6 | 25 | #include <linux/slab.h> |
0a270321 HX |
26 | #include <linux/spinlock.h> |
27 | #include <linux/string.h> | |
28 | ||
29 | struct seqiv_ctx { | |
30 | spinlock_t lock; | |
31 | u8 salt[] __attribute__ ((aligned(__alignof__(u32)))); | |
32 | }; | |
33 | ||
856e3f40 | 34 | struct seqiv_aead_ctx { |
661cfd0e HX |
35 | /* aead_geniv_ctx must be first the element */ |
36 | struct aead_geniv_ctx geniv; | |
856e3f40 HX |
37 | struct crypto_blkcipher *null; |
38 | u8 salt[] __attribute__ ((aligned(__alignof__(u32)))); | |
39 | }; | |
40 | ||
0677157b HX |
41 | static void seqiv_free(struct crypto_instance *inst); |
42 | ||
0a270321 HX |
43 | static void seqiv_complete2(struct skcipher_givcrypt_request *req, int err) |
44 | { | |
45 | struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req); | |
46 | struct crypto_ablkcipher *geniv; | |
47 | ||
48 | if (err == -EINPROGRESS) | |
49 | return; | |
50 | ||
51 | if (err) | |
52 | goto out; | |
53 | ||
54 | geniv = skcipher_givcrypt_reqtfm(req); | |
55 | memcpy(req->creq.info, subreq->info, crypto_ablkcipher_ivsize(geniv)); | |
56 | ||
57 | out: | |
58 | kfree(subreq->info); | |
59 | } | |
60 | ||
61 | static void seqiv_complete(struct crypto_async_request *base, int err) | |
62 | { | |
63 | struct skcipher_givcrypt_request *req = base->data; | |
64 | ||
65 | seqiv_complete2(req, err); | |
66 | skcipher_givcrypt_complete(req, err); | |
67 | } | |
68 | ||
856e3f40 HX |
69 | static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err) |
70 | { | |
71 | struct aead_request *subreq = aead_request_ctx(req); | |
72 | struct crypto_aead *geniv; | |
73 | ||
74 | if (err == -EINPROGRESS) | |
75 | return; | |
76 | ||
77 | if (err) | |
78 | goto out; | |
79 | ||
80 | geniv = crypto_aead_reqtfm(req); | |
81 | memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv)); | |
82 | ||
83 | out: | |
84 | kzfree(subreq->iv); | |
85 | } | |
86 | ||
87 | static void seqiv_aead_encrypt_complete(struct crypto_async_request *base, | |
88 | int err) | |
89 | { | |
90 | struct aead_request *req = base->data; | |
91 | ||
92 | seqiv_aead_encrypt_complete2(req, err); | |
93 | aead_request_complete(req, err); | |
94 | } | |
95 | ||
14df4d80 HX |
96 | static void seqiv_geniv(struct seqiv_ctx *ctx, u8 *info, u64 seq, |
97 | unsigned int ivsize) | |
98 | { | |
99 | unsigned int len = ivsize; | |
100 | ||
101 | if (ivsize > sizeof(u64)) { | |
102 | memset(info, 0, ivsize - sizeof(u64)); | |
103 | len = sizeof(u64); | |
104 | } | |
105 | seq = cpu_to_be64(seq); | |
106 | memcpy(info + ivsize - len, &seq, len); | |
107 | crypto_xor(info, ctx->salt, ivsize); | |
108 | } | |
109 | ||
0a270321 HX |
110 | static int seqiv_givencrypt(struct skcipher_givcrypt_request *req) |
111 | { | |
112 | struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req); | |
113 | struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv); | |
114 | struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req); | |
3e3dc25f | 115 | crypto_completion_t compl; |
0a270321 HX |
116 | void *data; |
117 | u8 *info; | |
0a270321 | 118 | unsigned int ivsize; |
0a270321 HX |
119 | int err; |
120 | ||
121 | ablkcipher_request_set_tfm(subreq, skcipher_geniv_cipher(geniv)); | |
122 | ||
3e3dc25f | 123 | compl = req->creq.base.complete; |
0a270321 HX |
124 | data = req->creq.base.data; |
125 | info = req->creq.info; | |
126 | ||
127 | ivsize = crypto_ablkcipher_ivsize(geniv); | |
128 | ||
129 | if (unlikely(!IS_ALIGNED((unsigned long)info, | |
130 | crypto_ablkcipher_alignmask(geniv) + 1))) { | |
131 | info = kmalloc(ivsize, req->creq.base.flags & | |
132 | CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL: | |
133 | GFP_ATOMIC); | |
134 | if (!info) | |
135 | return -ENOMEM; | |
136 | ||
3e3dc25f | 137 | compl = seqiv_complete; |
0a270321 HX |
138 | data = req; |
139 | } | |
140 | ||
3e3dc25f | 141 | ablkcipher_request_set_callback(subreq, req->creq.base.flags, compl, |
0a270321 HX |
142 | data); |
143 | ablkcipher_request_set_crypt(subreq, req->creq.src, req->creq.dst, | |
144 | req->creq.nbytes, info); | |
145 | ||
14df4d80 | 146 | seqiv_geniv(ctx, info, req->seq, ivsize); |
0a270321 HX |
147 | memcpy(req->giv, info, ivsize); |
148 | ||
149 | err = crypto_ablkcipher_encrypt(subreq); | |
150 | if (unlikely(info != req->creq.info)) | |
151 | seqiv_complete2(req, err); | |
152 | return err; | |
153 | } | |
154 | ||
856e3f40 HX |
155 | static int seqiv_aead_encrypt(struct aead_request *req) |
156 | { | |
157 | struct crypto_aead *geniv = crypto_aead_reqtfm(req); | |
158 | struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv); | |
159 | struct aead_request *subreq = aead_request_ctx(req); | |
160 | crypto_completion_t compl; | |
161 | void *data; | |
162 | u8 *info; | |
dd04446e | 163 | unsigned int ivsize = 8; |
856e3f40 HX |
164 | int err; |
165 | ||
dd04446e HX |
166 | if (req->cryptlen < ivsize) |
167 | return -EINVAL; | |
168 | ||
661cfd0e | 169 | aead_request_set_tfm(subreq, ctx->geniv.child); |
856e3f40 HX |
170 | |
171 | compl = req->base.complete; | |
172 | data = req->base.data; | |
173 | info = req->iv; | |
174 | ||
856e3f40 | 175 | if (req->src != req->dst) { |
856e3f40 HX |
176 | struct blkcipher_desc desc = { |
177 | .tfm = ctx->null, | |
178 | }; | |
179 | ||
d0ad1b24 HX |
180 | err = crypto_blkcipher_encrypt(&desc, req->dst, req->src, |
181 | req->assoclen + req->cryptlen); | |
856e3f40 HX |
182 | if (err) |
183 | return err; | |
184 | } | |
185 | ||
186 | if (unlikely(!IS_ALIGNED((unsigned long)info, | |
187 | crypto_aead_alignmask(geniv) + 1))) { | |
188 | info = kmalloc(ivsize, req->base.flags & | |
189 | CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL: | |
190 | GFP_ATOMIC); | |
191 | if (!info) | |
192 | return -ENOMEM; | |
193 | ||
194 | memcpy(info, req->iv, ivsize); | |
195 | compl = seqiv_aead_encrypt_complete; | |
196 | data = req; | |
197 | } | |
198 | ||
199 | aead_request_set_callback(subreq, req->base.flags, compl, data); | |
200 | aead_request_set_crypt(subreq, req->dst, req->dst, | |
201 | req->cryptlen - ivsize, info); | |
374d4ad1 | 202 | aead_request_set_ad(subreq, req->assoclen + ivsize); |
856e3f40 HX |
203 | |
204 | crypto_xor(info, ctx->salt, ivsize); | |
205 | scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1); | |
206 | ||
207 | err = crypto_aead_encrypt(subreq); | |
208 | if (unlikely(info != req->iv)) | |
209 | seqiv_aead_encrypt_complete2(req, err); | |
210 | return err; | |
211 | } | |
212 | ||
856e3f40 HX |
213 | static int seqiv_aead_decrypt(struct aead_request *req) |
214 | { | |
215 | struct crypto_aead *geniv = crypto_aead_reqtfm(req); | |
216 | struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv); | |
217 | struct aead_request *subreq = aead_request_ctx(req); | |
218 | crypto_completion_t compl; | |
219 | void *data; | |
dd04446e HX |
220 | unsigned int ivsize = 8; |
221 | ||
222 | if (req->cryptlen < ivsize + crypto_aead_authsize(geniv)) | |
223 | return -EINVAL; | |
856e3f40 | 224 | |
661cfd0e | 225 | aead_request_set_tfm(subreq, ctx->geniv.child); |
856e3f40 HX |
226 | |
227 | compl = req->base.complete; | |
228 | data = req->base.data; | |
229 | ||
856e3f40 HX |
230 | aead_request_set_callback(subreq, req->base.flags, compl, data); |
231 | aead_request_set_crypt(subreq, req->src, req->dst, | |
232 | req->cryptlen - ivsize, req->iv); | |
374d4ad1 | 233 | aead_request_set_ad(subreq, req->assoclen + ivsize); |
856e3f40 HX |
234 | |
235 | scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0); | |
856e3f40 HX |
236 | |
237 | return crypto_aead_decrypt(subreq); | |
238 | } | |
239 | ||
0a270321 HX |
240 | static int seqiv_init(struct crypto_tfm *tfm) |
241 | { | |
242 | struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm); | |
243 | struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv); | |
eeee12aa | 244 | int err; |
0a270321 HX |
245 | |
246 | spin_lock_init(&ctx->lock); | |
247 | ||
248 | tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request); | |
249 | ||
eeee12aa HX |
250 | err = 0; |
251 | if (!crypto_get_default_rng()) { | |
252 | crypto_ablkcipher_crt(geniv)->givencrypt = seqiv_givencrypt; | |
253 | err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt, | |
254 | crypto_ablkcipher_ivsize(geniv)); | |
255 | crypto_put_default_rng(); | |
256 | } | |
257 | ||
258 | return err ?: skcipher_geniv_init(tfm); | |
0a270321 HX |
259 | } |
260 | ||
5964f26c HX |
261 | static int seqiv_aead_init_common(struct crypto_aead *geniv, |
262 | unsigned int reqsize) | |
856e3f40 | 263 | { |
856e3f40 HX |
264 | struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv); |
265 | int err; | |
266 | ||
661cfd0e | 267 | spin_lock_init(&ctx->geniv.lock); |
856e3f40 HX |
268 | |
269 | crypto_aead_set_reqsize(geniv, sizeof(struct aead_request)); | |
270 | ||
eeee12aa HX |
271 | err = crypto_get_default_rng(); |
272 | if (err) | |
273 | goto out; | |
274 | ||
b7dcfab4 HX |
275 | err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt, |
276 | crypto_aead_ivsize(geniv)); | |
eeee12aa | 277 | crypto_put_default_rng(); |
b7dcfab4 HX |
278 | if (err) |
279 | goto out; | |
280 | ||
856e3f40 HX |
281 | ctx->null = crypto_get_default_null_skcipher(); |
282 | err = PTR_ERR(ctx->null); | |
283 | if (IS_ERR(ctx->null)) | |
284 | goto out; | |
285 | ||
5964f26c | 286 | err = aead_geniv_init(crypto_aead_tfm(geniv)); |
856e3f40 HX |
287 | if (err) |
288 | goto drop_null; | |
289 | ||
661cfd0e | 290 | ctx->geniv.child = geniv->child; |
856e3f40 HX |
291 | geniv->child = geniv; |
292 | ||
293 | out: | |
294 | return err; | |
295 | ||
296 | drop_null: | |
297 | crypto_put_default_null_skcipher(); | |
298 | goto out; | |
299 | } | |
300 | ||
5964f26c | 301 | static int seqiv_aead_init(struct crypto_aead *tfm) |
856e3f40 | 302 | { |
dd04446e HX |
303 | return seqiv_aead_init_common(tfm, sizeof(struct aead_request)); |
304 | } | |
856e3f40 | 305 | |
5964f26c | 306 | static void seqiv_aead_exit(struct crypto_aead *tfm) |
856e3f40 | 307 | { |
5964f26c | 308 | struct seqiv_aead_ctx *ctx = crypto_aead_ctx(tfm); |
856e3f40 | 309 | |
661cfd0e | 310 | crypto_free_aead(ctx->geniv.child); |
856e3f40 HX |
311 | crypto_put_default_null_skcipher(); |
312 | } | |
313 | ||
0677157b HX |
314 | static int seqiv_ablkcipher_create(struct crypto_template *tmpl, |
315 | struct rtattr **tb) | |
0a270321 HX |
316 | { |
317 | struct crypto_instance *inst; | |
0677157b | 318 | int err; |
0a270321 | 319 | |
0677157b | 320 | inst = skcipher_geniv_alloc(tmpl, tb, 0, 0); |
14df4d80 | 321 | |
0a270321 | 322 | if (IS_ERR(inst)) |
0677157b | 323 | return PTR_ERR(inst); |
0a270321 | 324 | |
0677157b HX |
325 | err = -EINVAL; |
326 | if (inst->alg.cra_ablkcipher.ivsize < sizeof(u64)) | |
327 | goto free_inst; | |
c0ecf891 | 328 | |
0a270321 HX |
329 | inst->alg.cra_init = seqiv_init; |
330 | inst->alg.cra_exit = skcipher_geniv_exit; | |
331 | ||
0a270321 | 332 | inst->alg.cra_ctxsize += inst->alg.cra_ablkcipher.ivsize; |
856e3f40 | 333 | inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx); |
0a270321 | 334 | |
0677157b HX |
335 | inst->alg.cra_alignmask |= __alignof__(u32) - 1; |
336 | ||
337 | err = crypto_register_instance(tmpl, inst); | |
338 | if (err) | |
339 | goto free_inst; | |
340 | ||
0a270321 | 341 | out: |
0677157b HX |
342 | return err; |
343 | ||
344 | free_inst: | |
345 | skcipher_geniv_free(inst); | |
346 | goto out; | |
0a270321 HX |
347 | } |
348 | ||
0677157b | 349 | static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb) |
14df4d80 | 350 | { |
856e3f40 HX |
351 | struct aead_instance *inst; |
352 | struct crypto_aead_spawn *spawn; | |
353 | struct aead_alg *alg; | |
0677157b | 354 | int err; |
14df4d80 | 355 | |
0677157b | 356 | inst = aead_geniv_alloc(tmpl, tb, 0, 0); |
14df4d80 HX |
357 | |
358 | if (IS_ERR(inst)) | |
0677157b HX |
359 | return PTR_ERR(inst); |
360 | ||
361 | inst->alg.base.cra_alignmask |= __alignof__(u32) - 1; | |
14df4d80 | 362 | |
661cfd0e HX |
363 | spawn = aead_instance_ctx(inst); |
364 | alg = crypto_spawn_aead_alg(spawn); | |
365 | ||
0677157b | 366 | err = -EINVAL; |
dd04446e | 367 | if (inst->alg.ivsize != sizeof(u64)) |
0677157b | 368 | goto free_inst; |
c0ecf891 | 369 | |
b7dcfab4 | 370 | inst->alg.encrypt = seqiv_aead_encrypt; |
856e3f40 | 371 | inst->alg.decrypt = seqiv_aead_decrypt; |
14df4d80 | 372 | |
5964f26c HX |
373 | inst->alg.init = seqiv_aead_init; |
374 | inst->alg.exit = seqiv_aead_exit; | |
856e3f40 HX |
375 | |
376 | inst->alg.base.cra_ctxsize = sizeof(struct seqiv_aead_ctx); | |
5964f26c | 377 | inst->alg.base.cra_ctxsize += inst->alg.ivsize; |
856e3f40 | 378 | |
0677157b HX |
379 | err = aead_register_instance(tmpl, inst); |
380 | if (err) | |
381 | goto free_inst; | |
382 | ||
14df4d80 | 383 | out: |
0677157b HX |
384 | return err; |
385 | ||
386 | free_inst: | |
387 | aead_geniv_free(inst); | |
388 | goto out; | |
14df4d80 HX |
389 | } |
390 | ||
0677157b | 391 | static int seqiv_create(struct crypto_template *tmpl, struct rtattr **tb) |
14df4d80 HX |
392 | { |
393 | struct crypto_attr_type *algt; | |
14df4d80 HX |
394 | int err; |
395 | ||
396 | algt = crypto_get_attr_type(tb); | |
14df4d80 | 397 | if (IS_ERR(algt)) |
0677157b | 398 | return PTR_ERR(algt); |
14df4d80 HX |
399 | |
400 | if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK) | |
0677157b | 401 | err = seqiv_ablkcipher_create(tmpl, tb); |
14df4d80 | 402 | else |
0677157b | 403 | err = seqiv_aead_create(tmpl, tb); |
14df4d80 | 404 | |
0677157b | 405 | return err; |
14df4d80 HX |
406 | } |
407 | ||
408 | static void seqiv_free(struct crypto_instance *inst) | |
409 | { | |
410 | if ((inst->alg.cra_flags ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK) | |
411 | skcipher_geniv_free(inst); | |
412 | else | |
856e3f40 | 413 | aead_geniv_free(aead_instance(inst)); |
14df4d80 HX |
414 | } |
415 | ||
0a270321 HX |
416 | static struct crypto_template seqiv_tmpl = { |
417 | .name = "seqiv", | |
0677157b | 418 | .create = seqiv_create, |
14df4d80 | 419 | .free = seqiv_free, |
0a270321 HX |
420 | .module = THIS_MODULE, |
421 | }; | |
422 | ||
423 | static int __init seqiv_module_init(void) | |
424 | { | |
8a2cd1c4 | 425 | return crypto_register_template(&seqiv_tmpl); |
0a270321 HX |
426 | } |
427 | ||
428 | static void __exit seqiv_module_exit(void) | |
429 | { | |
430 | crypto_unregister_template(&seqiv_tmpl); | |
431 | } | |
432 | ||
433 | module_init(seqiv_module_init); | |
434 | module_exit(seqiv_module_exit); | |
435 | ||
436 | MODULE_LICENSE("GPL"); | |
437 | MODULE_DESCRIPTION("Sequence Number IV Generator"); | |
4943ba16 | 438 | MODULE_ALIAS_CRYPTO("seqiv"); |