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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 <[email protected]> | |
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> |
a0f000ec | 18 | #include <crypto/rng.h> |
856e3f40 | 19 | #include <crypto/scatterwalk.h> |
0a270321 HX |
20 | #include <linux/err.h> |
21 | #include <linux/init.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/module.h> | |
5a0e3ad6 | 24 | #include <linux/slab.h> |
0a270321 HX |
25 | #include <linux/spinlock.h> |
26 | #include <linux/string.h> | |
27 | ||
28 | struct seqiv_ctx { | |
29 | spinlock_t lock; | |
30 | u8 salt[] __attribute__ ((aligned(__alignof__(u32)))); | |
31 | }; | |
32 | ||
0677157b HX |
33 | static void seqiv_free(struct crypto_instance *inst); |
34 | ||
0a270321 HX |
35 | static void seqiv_complete2(struct skcipher_givcrypt_request *req, int err) |
36 | { | |
37 | struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req); | |
38 | struct crypto_ablkcipher *geniv; | |
39 | ||
40 | if (err == -EINPROGRESS) | |
41 | return; | |
42 | ||
43 | if (err) | |
44 | goto out; | |
45 | ||
46 | geniv = skcipher_givcrypt_reqtfm(req); | |
47 | memcpy(req->creq.info, subreq->info, crypto_ablkcipher_ivsize(geniv)); | |
48 | ||
49 | out: | |
50 | kfree(subreq->info); | |
51 | } | |
52 | ||
53 | static void seqiv_complete(struct crypto_async_request *base, int err) | |
54 | { | |
55 | struct skcipher_givcrypt_request *req = base->data; | |
56 | ||
57 | seqiv_complete2(req, err); | |
58 | skcipher_givcrypt_complete(req, err); | |
59 | } | |
60 | ||
856e3f40 HX |
61 | static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err) |
62 | { | |
63 | struct aead_request *subreq = aead_request_ctx(req); | |
64 | struct crypto_aead *geniv; | |
65 | ||
66 | if (err == -EINPROGRESS) | |
67 | return; | |
68 | ||
69 | if (err) | |
70 | goto out; | |
71 | ||
72 | geniv = crypto_aead_reqtfm(req); | |
73 | memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv)); | |
74 | ||
75 | out: | |
76 | kzfree(subreq->iv); | |
77 | } | |
78 | ||
79 | static void seqiv_aead_encrypt_complete(struct crypto_async_request *base, | |
80 | int err) | |
81 | { | |
82 | struct aead_request *req = base->data; | |
83 | ||
84 | seqiv_aead_encrypt_complete2(req, err); | |
85 | aead_request_complete(req, err); | |
86 | } | |
87 | ||
14df4d80 HX |
88 | static void seqiv_geniv(struct seqiv_ctx *ctx, u8 *info, u64 seq, |
89 | unsigned int ivsize) | |
90 | { | |
91 | unsigned int len = ivsize; | |
92 | ||
93 | if (ivsize > sizeof(u64)) { | |
94 | memset(info, 0, ivsize - sizeof(u64)); | |
95 | len = sizeof(u64); | |
96 | } | |
97 | seq = cpu_to_be64(seq); | |
98 | memcpy(info + ivsize - len, &seq, len); | |
99 | crypto_xor(info, ctx->salt, ivsize); | |
100 | } | |
101 | ||
0a270321 HX |
102 | static int seqiv_givencrypt(struct skcipher_givcrypt_request *req) |
103 | { | |
104 | struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req); | |
105 | struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv); | |
106 | struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req); | |
3e3dc25f | 107 | crypto_completion_t compl; |
0a270321 HX |
108 | void *data; |
109 | u8 *info; | |
0a270321 | 110 | unsigned int ivsize; |
0a270321 HX |
111 | int err; |
112 | ||
113 | ablkcipher_request_set_tfm(subreq, skcipher_geniv_cipher(geniv)); | |
114 | ||
3e3dc25f | 115 | compl = req->creq.base.complete; |
0a270321 HX |
116 | data = req->creq.base.data; |
117 | info = req->creq.info; | |
118 | ||
119 | ivsize = crypto_ablkcipher_ivsize(geniv); | |
120 | ||
121 | if (unlikely(!IS_ALIGNED((unsigned long)info, | |
122 | crypto_ablkcipher_alignmask(geniv) + 1))) { | |
123 | info = kmalloc(ivsize, req->creq.base.flags & | |
124 | CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL: | |
125 | GFP_ATOMIC); | |
126 | if (!info) | |
127 | return -ENOMEM; | |
128 | ||
3e3dc25f | 129 | compl = seqiv_complete; |
0a270321 HX |
130 | data = req; |
131 | } | |
132 | ||
3e3dc25f | 133 | ablkcipher_request_set_callback(subreq, req->creq.base.flags, compl, |
0a270321 HX |
134 | data); |
135 | ablkcipher_request_set_crypt(subreq, req->creq.src, req->creq.dst, | |
136 | req->creq.nbytes, info); | |
137 | ||
14df4d80 | 138 | seqiv_geniv(ctx, info, req->seq, ivsize); |
0a270321 HX |
139 | memcpy(req->giv, info, ivsize); |
140 | ||
141 | err = crypto_ablkcipher_encrypt(subreq); | |
142 | if (unlikely(info != req->creq.info)) | |
143 | seqiv_complete2(req, err); | |
144 | return err; | |
145 | } | |
146 | ||
856e3f40 HX |
147 | static int seqiv_aead_encrypt(struct aead_request *req) |
148 | { | |
149 | struct crypto_aead *geniv = crypto_aead_reqtfm(req); | |
659e7f52 | 150 | struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv); |
856e3f40 HX |
151 | struct aead_request *subreq = aead_request_ctx(req); |
152 | crypto_completion_t compl; | |
153 | void *data; | |
154 | u8 *info; | |
dd04446e | 155 | unsigned int ivsize = 8; |
856e3f40 HX |
156 | int err; |
157 | ||
dd04446e HX |
158 | if (req->cryptlen < ivsize) |
159 | return -EINVAL; | |
160 | ||
659e7f52 | 161 | aead_request_set_tfm(subreq, ctx->child); |
856e3f40 HX |
162 | |
163 | compl = req->base.complete; | |
164 | data = req->base.data; | |
165 | info = req->iv; | |
166 | ||
856e3f40 | 167 | if (req->src != req->dst) { |
856e3f40 HX |
168 | struct blkcipher_desc desc = { |
169 | .tfm = ctx->null, | |
170 | }; | |
171 | ||
d0ad1b24 HX |
172 | err = crypto_blkcipher_encrypt(&desc, req->dst, req->src, |
173 | req->assoclen + req->cryptlen); | |
856e3f40 HX |
174 | if (err) |
175 | return err; | |
176 | } | |
177 | ||
178 | if (unlikely(!IS_ALIGNED((unsigned long)info, | |
179 | crypto_aead_alignmask(geniv) + 1))) { | |
180 | info = kmalloc(ivsize, req->base.flags & | |
181 | CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL: | |
182 | GFP_ATOMIC); | |
183 | if (!info) | |
184 | return -ENOMEM; | |
185 | ||
186 | memcpy(info, req->iv, ivsize); | |
187 | compl = seqiv_aead_encrypt_complete; | |
188 | data = req; | |
189 | } | |
190 | ||
191 | aead_request_set_callback(subreq, req->base.flags, compl, data); | |
192 | aead_request_set_crypt(subreq, req->dst, req->dst, | |
193 | req->cryptlen - ivsize, info); | |
374d4ad1 | 194 | aead_request_set_ad(subreq, req->assoclen + ivsize); |
856e3f40 HX |
195 | |
196 | crypto_xor(info, ctx->salt, ivsize); | |
197 | scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1); | |
198 | ||
199 | err = crypto_aead_encrypt(subreq); | |
200 | if (unlikely(info != req->iv)) | |
201 | seqiv_aead_encrypt_complete2(req, err); | |
202 | return err; | |
203 | } | |
204 | ||
856e3f40 HX |
205 | static int seqiv_aead_decrypt(struct aead_request *req) |
206 | { | |
207 | struct crypto_aead *geniv = crypto_aead_reqtfm(req); | |
659e7f52 | 208 | struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv); |
856e3f40 HX |
209 | struct aead_request *subreq = aead_request_ctx(req); |
210 | crypto_completion_t compl; | |
211 | void *data; | |
dd04446e HX |
212 | unsigned int ivsize = 8; |
213 | ||
214 | if (req->cryptlen < ivsize + crypto_aead_authsize(geniv)) | |
215 | return -EINVAL; | |
856e3f40 | 216 | |
659e7f52 | 217 | aead_request_set_tfm(subreq, ctx->child); |
856e3f40 HX |
218 | |
219 | compl = req->base.complete; | |
220 | data = req->base.data; | |
221 | ||
856e3f40 HX |
222 | aead_request_set_callback(subreq, req->base.flags, compl, data); |
223 | aead_request_set_crypt(subreq, req->src, req->dst, | |
224 | req->cryptlen - ivsize, req->iv); | |
374d4ad1 | 225 | aead_request_set_ad(subreq, req->assoclen + ivsize); |
856e3f40 HX |
226 | |
227 | scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0); | |
856e3f40 HX |
228 | |
229 | return crypto_aead_decrypt(subreq); | |
230 | } | |
231 | ||
0a270321 HX |
232 | static int seqiv_init(struct crypto_tfm *tfm) |
233 | { | |
234 | struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm); | |
235 | struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv); | |
eeee12aa | 236 | int err; |
0a270321 HX |
237 | |
238 | spin_lock_init(&ctx->lock); | |
239 | ||
240 | tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request); | |
241 | ||
eeee12aa HX |
242 | err = 0; |
243 | if (!crypto_get_default_rng()) { | |
244 | crypto_ablkcipher_crt(geniv)->givencrypt = seqiv_givencrypt; | |
245 | err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt, | |
246 | crypto_ablkcipher_ivsize(geniv)); | |
247 | crypto_put_default_rng(); | |
248 | } | |
249 | ||
250 | return err ?: skcipher_geniv_init(tfm); | |
0a270321 HX |
251 | } |
252 | ||
0677157b HX |
253 | static int seqiv_ablkcipher_create(struct crypto_template *tmpl, |
254 | struct rtattr **tb) | |
0a270321 HX |
255 | { |
256 | struct crypto_instance *inst; | |
0677157b | 257 | int err; |
0a270321 | 258 | |
0677157b | 259 | inst = skcipher_geniv_alloc(tmpl, tb, 0, 0); |
14df4d80 | 260 | |
0a270321 | 261 | if (IS_ERR(inst)) |
0677157b | 262 | return PTR_ERR(inst); |
0a270321 | 263 | |
0677157b HX |
264 | err = -EINVAL; |
265 | if (inst->alg.cra_ablkcipher.ivsize < sizeof(u64)) | |
266 | goto free_inst; | |
c0ecf891 | 267 | |
0a270321 HX |
268 | inst->alg.cra_init = seqiv_init; |
269 | inst->alg.cra_exit = skcipher_geniv_exit; | |
270 | ||
0a270321 | 271 | inst->alg.cra_ctxsize += inst->alg.cra_ablkcipher.ivsize; |
856e3f40 | 272 | inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx); |
0a270321 | 273 | |
0677157b HX |
274 | inst->alg.cra_alignmask |= __alignof__(u32) - 1; |
275 | ||
276 | err = crypto_register_instance(tmpl, inst); | |
277 | if (err) | |
278 | goto free_inst; | |
279 | ||
0a270321 | 280 | out: |
0677157b HX |
281 | return err; |
282 | ||
283 | free_inst: | |
284 | skcipher_geniv_free(inst); | |
285 | goto out; | |
0a270321 HX |
286 | } |
287 | ||
0677157b | 288 | static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb) |
14df4d80 | 289 | { |
856e3f40 HX |
290 | struct aead_instance *inst; |
291 | struct crypto_aead_spawn *spawn; | |
292 | struct aead_alg *alg; | |
0677157b | 293 | int err; |
14df4d80 | 294 | |
0677157b | 295 | inst = aead_geniv_alloc(tmpl, tb, 0, 0); |
14df4d80 HX |
296 | |
297 | if (IS_ERR(inst)) | |
0677157b HX |
298 | return PTR_ERR(inst); |
299 | ||
300 | inst->alg.base.cra_alignmask |= __alignof__(u32) - 1; | |
14df4d80 | 301 | |
661cfd0e HX |
302 | spawn = aead_instance_ctx(inst); |
303 | alg = crypto_spawn_aead_alg(spawn); | |
304 | ||
0677157b | 305 | err = -EINVAL; |
dd04446e | 306 | if (inst->alg.ivsize != sizeof(u64)) |
0677157b | 307 | goto free_inst; |
c0ecf891 | 308 | |
b7dcfab4 | 309 | inst->alg.encrypt = seqiv_aead_encrypt; |
856e3f40 | 310 | inst->alg.decrypt = seqiv_aead_decrypt; |
14df4d80 | 311 | |
659e7f52 HX |
312 | inst->alg.init = aead_init_geniv; |
313 | inst->alg.exit = aead_exit_geniv; | |
856e3f40 | 314 | |
659e7f52 | 315 | inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx); |
5964f26c | 316 | inst->alg.base.cra_ctxsize += inst->alg.ivsize; |
856e3f40 | 317 | |
0677157b HX |
318 | err = aead_register_instance(tmpl, inst); |
319 | if (err) | |
320 | goto free_inst; | |
321 | ||
14df4d80 | 322 | out: |
0677157b HX |
323 | return err; |
324 | ||
325 | free_inst: | |
326 | aead_geniv_free(inst); | |
327 | goto out; | |
14df4d80 HX |
328 | } |
329 | ||
0677157b | 330 | static int seqiv_create(struct crypto_template *tmpl, struct rtattr **tb) |
14df4d80 HX |
331 | { |
332 | struct crypto_attr_type *algt; | |
14df4d80 HX |
333 | int err; |
334 | ||
335 | algt = crypto_get_attr_type(tb); | |
14df4d80 | 336 | if (IS_ERR(algt)) |
0677157b | 337 | return PTR_ERR(algt); |
14df4d80 HX |
338 | |
339 | if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK) | |
0677157b | 340 | err = seqiv_ablkcipher_create(tmpl, tb); |
14df4d80 | 341 | else |
0677157b | 342 | err = seqiv_aead_create(tmpl, tb); |
14df4d80 | 343 | |
0677157b | 344 | return err; |
14df4d80 HX |
345 | } |
346 | ||
347 | static void seqiv_free(struct crypto_instance *inst) | |
348 | { | |
349 | if ((inst->alg.cra_flags ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK) | |
350 | skcipher_geniv_free(inst); | |
351 | else | |
856e3f40 | 352 | aead_geniv_free(aead_instance(inst)); |
14df4d80 HX |
353 | } |
354 | ||
0a270321 HX |
355 | static struct crypto_template seqiv_tmpl = { |
356 | .name = "seqiv", | |
0677157b | 357 | .create = seqiv_create, |
14df4d80 | 358 | .free = seqiv_free, |
0a270321 HX |
359 | .module = THIS_MODULE, |
360 | }; | |
361 | ||
362 | static int __init seqiv_module_init(void) | |
363 | { | |
8a2cd1c4 | 364 | return crypto_register_template(&seqiv_tmpl); |
0a270321 HX |
365 | } |
366 | ||
367 | static void __exit seqiv_module_exit(void) | |
368 | { | |
369 | crypto_unregister_template(&seqiv_tmpl); | |
370 | } | |
371 | ||
372 | module_init(seqiv_module_init); | |
373 | module_exit(seqiv_module_exit); | |
374 | ||
375 | MODULE_LICENSE("GPL"); | |
376 | MODULE_DESCRIPTION("Sequence Number IV Generator"); | |
4943ba16 | 377 | MODULE_ALIAS_CRYPTO("seqiv"); |