Blame view
crypto/cts.c
11.9 KB
76cb95217 [CRYPTO] cts: Add... |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 |
/* * CTS: Cipher Text Stealing mode * * COPYRIGHT (c) 2008 * The Regents of the University of Michigan * ALL RIGHTS RESERVED * * Permission is granted to use, copy, create derivative works * and redistribute this software and such derivative works * for any purpose, so long as the name of The University of * Michigan is not used in any advertising or publicity * pertaining to the use of distribution of this software * without specific, written prior authorization. If the * above copyright notice or any other identification of the * University of Michigan is included in any copy of any * portion of this software, then the disclaimer below must * also be included. * * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF * SUCH DAMAGES. */ /* Derived from various: * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au> */ /* * This is the Cipher Text Stealing mode as described by * Section 8 of rfc2040 and referenced by rfc3962. * rfc3962 includes errata information in its Appendix A. */ |
6650c4de6 crypto: remove se... |
42 |
#include <crypto/algapi.h> |
0605c41cc crypto: cts - Con... |
43 |
#include <crypto/internal/skcipher.h> |
76cb95217 [CRYPTO] cts: Add... |
44 45 46 47 48 49 50 51 |
#include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/log2.h> #include <linux/module.h> #include <linux/scatterlist.h> #include <crypto/scatterwalk.h> #include <linux/slab.h> |
d8c34b949 crypto: Replaced ... |
52 |
#include <linux/compiler.h> |
76cb95217 [CRYPTO] cts: Add... |
53 54 |
struct crypto_cts_ctx { |
0605c41cc crypto: cts - Con... |
55 |
struct crypto_skcipher *child; |
76cb95217 [CRYPTO] cts: Add... |
56 |
}; |
0605c41cc crypto: cts - Con... |
57 58 59 60 61 62 63 |
struct crypto_cts_reqctx { struct scatterlist sg[2]; unsigned offset; struct skcipher_request subreq; }; static inline u8 *crypto_cts_reqctx_space(struct skcipher_request *req) |
76cb95217 [CRYPTO] cts: Add... |
64 |
{ |
0605c41cc crypto: cts - Con... |
65 66 67 68 |
struct crypto_cts_reqctx *rctx = skcipher_request_ctx(req); struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(tfm); struct crypto_skcipher *child = ctx->child; |
76cb95217 [CRYPTO] cts: Add... |
69 |
|
0605c41cc crypto: cts - Con... |
70 71 |
return PTR_ALIGN((u8 *)(rctx + 1) + crypto_skcipher_reqsize(child), crypto_skcipher_alignmask(tfm) + 1); |
76cb95217 [CRYPTO] cts: Add... |
72 |
} |
0605c41cc crypto: cts - Con... |
73 74 |
static int crypto_cts_setkey(struct crypto_skcipher *parent, const u8 *key, unsigned int keylen) |
76cb95217 [CRYPTO] cts: Add... |
75 |
{ |
0605c41cc crypto: cts - Con... |
76 77 |
struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(parent); struct crypto_skcipher *child = ctx->child; |
76cb95217 [CRYPTO] cts: Add... |
78 |
|
0605c41cc crypto: cts - Con... |
79 80 81 |
crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK); crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) & CRYPTO_TFM_REQ_MASK); |
af5034e8e crypto: remove pr... |
82 |
return crypto_skcipher_setkey(child, key, keylen); |
0605c41cc crypto: cts - Con... |
83 |
} |
76cb95217 [CRYPTO] cts: Add... |
84 |
|
0605c41cc crypto: cts - Con... |
85 86 87 |
static void cts_cbc_crypt_done(struct crypto_async_request *areq, int err) { struct skcipher_request *req = areq->data; |
c4913c7b7 [CRYPTO] cts: Ini... |
88 |
|
0605c41cc crypto: cts - Con... |
89 90 |
if (err == -EINPROGRESS) return; |
76cb95217 [CRYPTO] cts: Add... |
91 |
|
0605c41cc crypto: cts - Con... |
92 93 |
skcipher_request_complete(req, err); } |
76cb95217 [CRYPTO] cts: Add... |
94 |
|
0605c41cc crypto: cts - Con... |
95 96 97 98 99 100 |
static int cts_cbc_encrypt(struct skcipher_request *req) { struct crypto_cts_reqctx *rctx = skcipher_request_ctx(req); struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct skcipher_request *subreq = &rctx->subreq; int bsize = crypto_skcipher_blocksize(tfm); |
6650c4de6 crypto: remove se... |
101 |
u8 d[MAX_CIPHER_BLOCKSIZE * 2] __aligned(__alignof__(u32)); |
0605c41cc crypto: cts - Con... |
102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 |
struct scatterlist *sg; unsigned int offset; int lastn; offset = rctx->offset; lastn = req->cryptlen - offset; sg = scatterwalk_ffwd(rctx->sg, req->dst, offset - bsize); scatterwalk_map_and_copy(d + bsize, sg, 0, bsize, 0); memset(d, 0, bsize); scatterwalk_map_and_copy(d, req->src, offset, lastn, 0); scatterwalk_map_and_copy(d, sg, 0, bsize + lastn, 1); memzero_explicit(d, sizeof(d)); skcipher_request_set_callback(subreq, req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG, cts_cbc_crypt_done, req); skcipher_request_set_crypt(subreq, sg, sg, bsize, req->iv); return crypto_skcipher_encrypt(subreq); } |
76cb95217 [CRYPTO] cts: Add... |
124 |
|
0605c41cc crypto: cts - Con... |
125 126 127 |
static void crypto_cts_encrypt_done(struct crypto_async_request *areq, int err) { struct skcipher_request *req = areq->data; |
76cb95217 [CRYPTO] cts: Add... |
128 |
|
0605c41cc crypto: cts - Con... |
129 130 |
if (err) goto out; |
76cb95217 [CRYPTO] cts: Add... |
131 |
|
0605c41cc crypto: cts - Con... |
132 |
err = cts_cbc_encrypt(req); |
4e5b0ad58 crypto: remove re... |
133 |
if (err == -EINPROGRESS || err == -EBUSY) |
0605c41cc crypto: cts - Con... |
134 |
return; |
76cb95217 [CRYPTO] cts: Add... |
135 |
|
0605c41cc crypto: cts - Con... |
136 137 138 |
out: skcipher_request_complete(req, err); } |
76cb95217 [CRYPTO] cts: Add... |
139 |
|
0605c41cc crypto: cts - Con... |
140 141 142 143 144 145 146 147 |
static int crypto_cts_encrypt(struct skcipher_request *req) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct crypto_cts_reqctx *rctx = skcipher_request_ctx(req); struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(tfm); struct skcipher_request *subreq = &rctx->subreq; int bsize = crypto_skcipher_blocksize(tfm); unsigned int nbytes = req->cryptlen; |
0605c41cc crypto: cts - Con... |
148 149 150 |
unsigned int offset; skcipher_request_set_tfm(subreq, ctx->child); |
c31a87198 crypto: cts - don... |
151 152 153 154 |
if (nbytes < bsize) return -EINVAL; if (nbytes == bsize) { |
0605c41cc crypto: cts - Con... |
155 156 157 158 159 160 161 |
skcipher_request_set_callback(subreq, req->base.flags, req->base.complete, req->base.data); skcipher_request_set_crypt(subreq, req->src, req->dst, nbytes, req->iv); return crypto_skcipher_encrypt(subreq); } |
76cb95217 [CRYPTO] cts: Add... |
162 |
|
c31a87198 crypto: cts - don... |
163 |
offset = rounddown(nbytes - 1, bsize); |
0605c41cc crypto: cts - Con... |
164 |
rctx->offset = offset; |
76cb95217 [CRYPTO] cts: Add... |
165 |
|
0605c41cc crypto: cts - Con... |
166 167 168 169 |
skcipher_request_set_callback(subreq, req->base.flags, crypto_cts_encrypt_done, req); skcipher_request_set_crypt(subreq, req->src, req->dst, offset, req->iv); |
76cb95217 [CRYPTO] cts: Add... |
170 |
|
0605c41cc crypto: cts - Con... |
171 172 |
return crypto_skcipher_encrypt(subreq) ?: cts_cbc_encrypt(req); |
76cb95217 [CRYPTO] cts: Add... |
173 |
} |
0605c41cc crypto: cts - Con... |
174 |
static int cts_cbc_decrypt(struct skcipher_request *req) |
76cb95217 [CRYPTO] cts: Add... |
175 |
{ |
0605c41cc crypto: cts - Con... |
176 177 178 179 |
struct crypto_cts_reqctx *rctx = skcipher_request_ctx(req); struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct skcipher_request *subreq = &rctx->subreq; int bsize = crypto_skcipher_blocksize(tfm); |
6650c4de6 crypto: remove se... |
180 |
u8 d[MAX_CIPHER_BLOCKSIZE * 2] __aligned(__alignof__(u32)); |
0605c41cc crypto: cts - Con... |
181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 |
struct scatterlist *sg; unsigned int offset; u8 *space; int lastn; offset = rctx->offset; lastn = req->cryptlen - offset; sg = scatterwalk_ffwd(rctx->sg, req->dst, offset - bsize); /* 1. Decrypt Cn-1 (s) to create Dn */ scatterwalk_map_and_copy(d + bsize, sg, 0, bsize, 0); space = crypto_cts_reqctx_space(req); crypto_xor(d + bsize, space, bsize); /* 2. Pad Cn with zeros at the end to create C of length BB */ memset(d, 0, bsize); scatterwalk_map_and_copy(d, req->src, offset, lastn, 0); /* 3. Exclusive-or Dn with C to create Xn */ /* 4. Select the first Ln bytes of Xn to create Pn */ crypto_xor(d + bsize, d, lastn); /* 5. Append the tail (BB - Ln) bytes of Xn to Cn to create En */ memcpy(d + lastn, d + bsize + lastn, bsize - lastn); /* 6. Decrypt En to create Pn-1 */ |
76cb95217 [CRYPTO] cts: Add... |
205 |
|
0605c41cc crypto: cts - Con... |
206 207 |
scatterwalk_map_and_copy(d, sg, 0, bsize + lastn, 1); memzero_explicit(d, sizeof(d)); |
76cb95217 [CRYPTO] cts: Add... |
208 |
|
0605c41cc crypto: cts - Con... |
209 210 211 212 213 214 |
skcipher_request_set_callback(subreq, req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG, cts_cbc_crypt_done, req); skcipher_request_set_crypt(subreq, sg, sg, bsize, space); return crypto_skcipher_decrypt(subreq); |
76cb95217 [CRYPTO] cts: Add... |
215 |
} |
0605c41cc crypto: cts - Con... |
216 |
static void crypto_cts_decrypt_done(struct crypto_async_request *areq, int err) |
76cb95217 [CRYPTO] cts: Add... |
217 |
{ |
0605c41cc crypto: cts - Con... |
218 |
struct skcipher_request *req = areq->data; |
76cb95217 [CRYPTO] cts: Add... |
219 |
|
0605c41cc crypto: cts - Con... |
220 221 |
if (err) goto out; |
c4913c7b7 [CRYPTO] cts: Ini... |
222 |
|
0605c41cc crypto: cts - Con... |
223 |
err = cts_cbc_decrypt(req); |
4e5b0ad58 crypto: remove re... |
224 |
if (err == -EINPROGRESS || err == -EBUSY) |
0605c41cc crypto: cts - Con... |
225 |
return; |
76cb95217 [CRYPTO] cts: Add... |
226 |
|
0605c41cc crypto: cts - Con... |
227 228 229 |
out: skcipher_request_complete(req, err); } |
76cb95217 [CRYPTO] cts: Add... |
230 |
|
0605c41cc crypto: cts - Con... |
231 232 233 234 235 236 237 238 |
static int crypto_cts_decrypt(struct skcipher_request *req) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct crypto_cts_reqctx *rctx = skcipher_request_ctx(req); struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(tfm); struct skcipher_request *subreq = &rctx->subreq; int bsize = crypto_skcipher_blocksize(tfm); unsigned int nbytes = req->cryptlen; |
0605c41cc crypto: cts - Con... |
239 240 241 242 |
unsigned int offset; u8 *space; skcipher_request_set_tfm(subreq, ctx->child); |
c31a87198 crypto: cts - don... |
243 244 245 246 |
if (nbytes < bsize) return -EINVAL; if (nbytes == bsize) { |
0605c41cc crypto: cts - Con... |
247 248 249 250 251 252 253 |
skcipher_request_set_callback(subreq, req->base.flags, req->base.complete, req->base.data); skcipher_request_set_crypt(subreq, req->src, req->dst, nbytes, req->iv); return crypto_skcipher_decrypt(subreq); } |
7185ad267 crypto: memzero_e... |
254 |
|
0605c41cc crypto: cts - Con... |
255 256 |
skcipher_request_set_callback(subreq, req->base.flags, crypto_cts_decrypt_done, req); |
76cb95217 [CRYPTO] cts: Add... |
257 |
|
0605c41cc crypto: cts - Con... |
258 |
space = crypto_cts_reqctx_space(req); |
76cb95217 [CRYPTO] cts: Add... |
259 |
|
c31a87198 crypto: cts - don... |
260 |
offset = rounddown(nbytes - 1, bsize); |
0605c41cc crypto: cts - Con... |
261 |
rctx->offset = offset; |
76cb95217 [CRYPTO] cts: Add... |
262 |
|
c31a87198 crypto: cts - don... |
263 |
if (offset <= bsize) |
0605c41cc crypto: cts - Con... |
264 265 266 267 |
memcpy(space, req->iv, bsize); else scatterwalk_map_and_copy(space, req->src, offset - 2 * bsize, bsize, 0); |
76cb95217 [CRYPTO] cts: Add... |
268 |
|
0605c41cc crypto: cts - Con... |
269 270 |
skcipher_request_set_crypt(subreq, req->src, req->dst, offset, req->iv); |
76cb95217 [CRYPTO] cts: Add... |
271 |
|
0605c41cc crypto: cts - Con... |
272 273 |
return crypto_skcipher_decrypt(subreq) ?: cts_cbc_decrypt(req); |
76cb95217 [CRYPTO] cts: Add... |
274 |
} |
0605c41cc crypto: cts - Con... |
275 |
static int crypto_cts_init_tfm(struct crypto_skcipher *tfm) |
76cb95217 [CRYPTO] cts: Add... |
276 |
{ |
0605c41cc crypto: cts - Con... |
277 278 279 280 281 282 283 |
struct skcipher_instance *inst = skcipher_alg_instance(tfm); struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst); struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(tfm); struct crypto_skcipher *cipher; unsigned reqsize; unsigned bsize; unsigned align; |
60425a8ba crypto: skcipher ... |
284 |
cipher = crypto_spawn_skcipher(spawn); |
76cb95217 [CRYPTO] cts: Add... |
285 286 287 288 |
if (IS_ERR(cipher)) return PTR_ERR(cipher); ctx->child = cipher; |
0605c41cc crypto: cts - Con... |
289 290 291 292 293 294 295 296 297 |
align = crypto_skcipher_alignmask(tfm); bsize = crypto_skcipher_blocksize(cipher); reqsize = ALIGN(sizeof(struct crypto_cts_reqctx) + crypto_skcipher_reqsize(cipher), crypto_tfm_ctx_alignment()) + (align & ~(crypto_tfm_ctx_alignment() - 1)) + bsize; crypto_skcipher_set_reqsize(tfm, reqsize); |
76cb95217 [CRYPTO] cts: Add... |
298 299 |
return 0; } |
0605c41cc crypto: cts - Con... |
300 |
static void crypto_cts_exit_tfm(struct crypto_skcipher *tfm) |
76cb95217 [CRYPTO] cts: Add... |
301 |
{ |
0605c41cc crypto: cts - Con... |
302 303 304 |
struct crypto_cts_ctx *ctx = crypto_skcipher_ctx(tfm); crypto_free_skcipher(ctx->child); |
76cb95217 [CRYPTO] cts: Add... |
305 |
} |
0605c41cc crypto: cts - Con... |
306 |
static void crypto_cts_free(struct skcipher_instance *inst) |
76cb95217 [CRYPTO] cts: Add... |
307 |
{ |
0605c41cc crypto: cts - Con... |
308 309 310 311 312 313 314 315 316 317 318 |
crypto_drop_skcipher(skcipher_instance_ctx(inst)); kfree(inst); } static int crypto_cts_create(struct crypto_template *tmpl, struct rtattr **tb) { struct crypto_skcipher_spawn *spawn; struct skcipher_instance *inst; struct crypto_attr_type *algt; struct skcipher_alg *alg; const char *cipher_name; |
b9f76dddb crypto: skcipher ... |
319 |
u32 mask; |
76cb95217 [CRYPTO] cts: Add... |
320 |
int err; |
0605c41cc crypto: cts - Con... |
321 322 323 324 325 326 |
algt = crypto_get_attr_type(tb); if (IS_ERR(algt)) return PTR_ERR(algt); if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask) return -EINVAL; |
b9f76dddb crypto: skcipher ... |
327 |
mask = crypto_requires_sync(algt->type, algt->mask); |
0605c41cc crypto: cts - Con... |
328 329 330 331 332 333 334 335 336 |
cipher_name = crypto_attr_alg_name(tb[1]); if (IS_ERR(cipher_name)) return PTR_ERR(cipher_name); inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); if (!inst) return -ENOMEM; spawn = skcipher_instance_ctx(inst); |
b9f76dddb crypto: skcipher ... |
337 338 |
err = crypto_grab_skcipher(spawn, skcipher_crypto_instance(inst), cipher_name, 0, mask); |
76cb95217 [CRYPTO] cts: Add... |
339 |
if (err) |
0605c41cc crypto: cts - Con... |
340 |
goto err_free_inst; |
76cb95217 [CRYPTO] cts: Add... |
341 |
|
0605c41cc crypto: cts - Con... |
342 |
alg = crypto_spawn_skcipher_alg(spawn); |
76cb95217 [CRYPTO] cts: Add... |
343 |
|
0605c41cc crypto: cts - Con... |
344 345 346 |
err = -EINVAL; if (crypto_skcipher_alg_ivsize(alg) != alg->base.cra_blocksize) goto err_drop_spawn; |
76cb95217 [CRYPTO] cts: Add... |
347 |
|
0605c41cc crypto: cts - Con... |
348 349 |
if (strncmp(alg->base.cra_name, "cbc(", 4)) goto err_drop_spawn; |
988dc0174 crypto: cts - Wee... |
350 |
|
0605c41cc crypto: cts - Con... |
351 352 353 354 |
err = crypto_inst_setname(skcipher_crypto_instance(inst), "cts", &alg->base); if (err) goto err_drop_spawn; |
76cb95217 [CRYPTO] cts: Add... |
355 |
|
0605c41cc crypto: cts - Con... |
356 357 358 359 |
inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC; inst->alg.base.cra_priority = alg->base.cra_priority; inst->alg.base.cra_blocksize = alg->base.cra_blocksize; inst->alg.base.cra_alignmask = alg->base.cra_alignmask; |
76cb95217 [CRYPTO] cts: Add... |
360 |
|
0605c41cc crypto: cts - Con... |
361 362 363 364 |
inst->alg.ivsize = alg->base.cra_blocksize; inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg); inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg); inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg); |
76cb95217 [CRYPTO] cts: Add... |
365 |
|
0605c41cc crypto: cts - Con... |
366 |
inst->alg.base.cra_ctxsize = sizeof(struct crypto_cts_ctx); |
76cb95217 [CRYPTO] cts: Add... |
367 |
|
0605c41cc crypto: cts - Con... |
368 369 |
inst->alg.init = crypto_cts_init_tfm; inst->alg.exit = crypto_cts_exit_tfm; |
76cb95217 [CRYPTO] cts: Add... |
370 |
|
0605c41cc crypto: cts - Con... |
371 372 373 |
inst->alg.setkey = crypto_cts_setkey; inst->alg.encrypt = crypto_cts_encrypt; inst->alg.decrypt = crypto_cts_decrypt; |
76cb95217 [CRYPTO] cts: Add... |
374 |
|
0605c41cc crypto: cts - Con... |
375 |
inst->free = crypto_cts_free; |
76cb95217 [CRYPTO] cts: Add... |
376 |
|
0605c41cc crypto: cts - Con... |
377 378 379 380 381 382 383 384 385 386 |
err = skcipher_register_instance(tmpl, inst); if (err) goto err_drop_spawn; out: return err; err_drop_spawn: crypto_drop_skcipher(spawn); err_free_inst: |
76cb95217 [CRYPTO] cts: Add... |
387 |
kfree(inst); |
0605c41cc crypto: cts - Con... |
388 |
goto out; |
76cb95217 [CRYPTO] cts: Add... |
389 390 391 392 |
} static struct crypto_template crypto_cts_tmpl = { .name = "cts", |
0605c41cc crypto: cts - Con... |
393 |
.create = crypto_cts_create, |
76cb95217 [CRYPTO] cts: Add... |
394 395 396 397 398 399 400 401 402 403 404 405 |
.module = THIS_MODULE, }; static int __init crypto_cts_module_init(void) { return crypto_register_template(&crypto_cts_tmpl); } static void __exit crypto_cts_module_exit(void) { crypto_unregister_template(&crypto_cts_tmpl); } |
c4741b230 crypto: run initc... |
406 |
subsys_initcall(crypto_cts_module_init); |
76cb95217 [CRYPTO] cts: Add... |
407 408 409 410 |
module_exit(crypto_cts_module_exit); MODULE_LICENSE("Dual BSD/GPL"); MODULE_DESCRIPTION("CTS-CBC CipherText Stealing for CBC"); |
4943ba16b crypto: include c... |
411 |
MODULE_ALIAS_CRYPTO("cts"); |