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Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +10001/*
2 * Copyright (C)2006 USAGI/WIDE Project
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Author:
19 * Kazunori Miyazawa <miyazawa@linux-ipv6.org>
20 */
21
Herbert Xu42c271c2007-12-07 18:52:49 +080022#include <crypto/scatterwalk.h>
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +100023#include <linux/crypto.h>
24#include <linux/err.h>
Herbert Xufb469842006-12-10 10:45:28 +110025#include <linux/hardirq.h>
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +100026#include <linux/kernel.h>
27#include <linux/mm.h>
28#include <linux/rtnetlink.h>
29#include <linux/slab.h>
30#include <linux/scatterlist.h>
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +100031
Adrian Bunk5b375382006-11-17 13:43:04 +110032static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
33 0x02020202, 0x02020202, 0x02020202, 0x02020202,
34 0x03030303, 0x03030303, 0x03030303, 0x03030303};
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +100035/*
36 * +------------------------
37 * | <parent tfm>
38 * +------------------------
39 * | crypto_xcbc_ctx
40 * +------------------------
41 * | odds (block size)
42 * +------------------------
43 * | prev (block size)
44 * +------------------------
45 * | key (block size)
46 * +------------------------
47 * | consts (block size * 3)
48 * +------------------------
49 */
50struct crypto_xcbc_ctx {
Herbert Xu6b701dd2006-12-24 09:59:42 +110051 struct crypto_cipher *child;
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +100052 u8 *odds;
53 u8 *prev;
54 u8 *key;
55 u8 *consts;
56 void (*xor)(u8 *a, const u8 *b, unsigned int bs);
57 unsigned int keylen;
58 unsigned int len;
59};
60
61static void xor_128(u8 *a, const u8 *b, unsigned int bs)
62{
63 ((u32 *)a)[0] ^= ((u32 *)b)[0];
64 ((u32 *)a)[1] ^= ((u32 *)b)[1];
65 ((u32 *)a)[2] ^= ((u32 *)b)[2];
66 ((u32 *)a)[3] ^= ((u32 *)b)[3];
67}
68
69static int _crypto_xcbc_digest_setkey(struct crypto_hash *parent,
70 struct crypto_xcbc_ctx *ctx)
71{
72 int bs = crypto_hash_blocksize(parent);
73 int err = 0;
74 u8 key1[bs];
75
76 if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
77 return err;
78
Herbert Xu6b701dd2006-12-24 09:59:42 +110079 crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +100080
81 return crypto_cipher_setkey(ctx->child, key1, bs);
82}
83
84static int crypto_xcbc_digest_setkey(struct crypto_hash *parent,
85 const u8 *inkey, unsigned int keylen)
86{
87 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
88
Herbert Xu6b701dd2006-12-24 09:59:42 +110089 if (keylen != crypto_cipher_blocksize(ctx->child))
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +100090 return -EINVAL;
91
92 ctx->keylen = keylen;
93 memcpy(ctx->key, inkey, keylen);
94 ctx->consts = (u8*)ks;
95
96 return _crypto_xcbc_digest_setkey(parent, ctx);
97}
98
Adrian Bunk5b375382006-11-17 13:43:04 +110099static int crypto_xcbc_digest_init(struct hash_desc *pdesc)
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000100{
101 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(pdesc->tfm);
102 int bs = crypto_hash_blocksize(pdesc->tfm);
103
104 ctx->len = 0;
105 memset(ctx->odds, 0, bs);
106 memset(ctx->prev, 0, bs);
107
108 return 0;
109}
110
Herbert Xufb469842006-12-10 10:45:28 +1100111static int crypto_xcbc_digest_update2(struct hash_desc *pdesc,
112 struct scatterlist *sg,
113 unsigned int nbytes)
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000114{
115 struct crypto_hash *parent = pdesc->tfm;
116 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
Herbert Xu6b701dd2006-12-24 09:59:42 +1100117 struct crypto_cipher *tfm = ctx->child;
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000118 int bs = crypto_hash_blocksize(parent);
119 unsigned int i = 0;
120
121 do {
122
Jens Axboe78c2f0b2007-10-22 19:40:16 +0200123 struct page *pg = sg_page(&sg[i]);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000124 unsigned int offset = sg[i].offset;
125 unsigned int slen = sg[i].length;
126
127 while (slen > 0) {
128 unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
129 char *p = crypto_kmap(pg, 0) + offset;
130
131 /* checking the data can fill the block */
132 if ((ctx->len + len) <= bs) {
133 memcpy(ctx->odds + ctx->len, p, len);
134 ctx->len += len;
135 slen -= len;
136
137 /* checking the rest of the page */
138 if (len + offset >= PAGE_SIZE) {
139 offset = 0;
140 pg++;
141 } else
142 offset += len;
143
144 crypto_kunmap(p, 0);
Herbert Xu6b701dd2006-12-24 09:59:42 +1100145 crypto_yield(pdesc->flags);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000146 continue;
147 }
148
149 /* filling odds with new data and encrypting it */
150 memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
151 len -= bs - ctx->len;
152 p += bs - ctx->len;
153
154 ctx->xor(ctx->prev, ctx->odds, bs);
Herbert Xu6b701dd2006-12-24 09:59:42 +1100155 crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000156
157 /* clearing the length */
158 ctx->len = 0;
159
160 /* encrypting the rest of data */
161 while (len > bs) {
162 ctx->xor(ctx->prev, p, bs);
Herbert Xu6b701dd2006-12-24 09:59:42 +1100163 crypto_cipher_encrypt_one(tfm, ctx->prev,
164 ctx->prev);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000165 p += bs;
166 len -= bs;
167 }
168
169 /* keeping the surplus of blocksize */
170 if (len) {
171 memcpy(ctx->odds, p, len);
172 ctx->len = len;
173 }
174 crypto_kunmap(p, 0);
Herbert Xu6b701dd2006-12-24 09:59:42 +1100175 crypto_yield(pdesc->flags);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000176 slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
177 offset = 0;
178 pg++;
179 }
180 nbytes-=sg[i].length;
181 i++;
182 } while (nbytes>0);
183
184 return 0;
185}
186
Herbert Xufb469842006-12-10 10:45:28 +1100187static int crypto_xcbc_digest_update(struct hash_desc *pdesc,
188 struct scatterlist *sg,
189 unsigned int nbytes)
190{
191 if (WARN_ON_ONCE(in_irq()))
192 return -EDEADLK;
193 return crypto_xcbc_digest_update2(pdesc, sg, nbytes);
194}
195
Adrian Bunk5b375382006-11-17 13:43:04 +1100196static int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out)
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000197{
198 struct crypto_hash *parent = pdesc->tfm;
199 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
Herbert Xu6b701dd2006-12-24 09:59:42 +1100200 struct crypto_cipher *tfm = ctx->child;
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000201 int bs = crypto_hash_blocksize(parent);
202 int err = 0;
203
204 if (ctx->len == bs) {
205 u8 key2[bs];
206
207 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
208 return err;
209
Herbert Xu6b701dd2006-12-24 09:59:42 +1100210 crypto_cipher_encrypt_one(tfm, key2,
211 (u8 *)(ctx->consts + bs));
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000212
213 ctx->xor(ctx->prev, ctx->odds, bs);
214 ctx->xor(ctx->prev, key2, bs);
215 _crypto_xcbc_digest_setkey(parent, ctx);
216
Herbert Xu6b701dd2006-12-24 09:59:42 +1100217 crypto_cipher_encrypt_one(tfm, out, ctx->prev);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000218 } else {
219 u8 key3[bs];
220 unsigned int rlen;
221 u8 *p = ctx->odds + ctx->len;
222 *p = 0x80;
223 p++;
224
225 rlen = bs - ctx->len -1;
226 if (rlen)
227 memset(p, 0, rlen);
228
229 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
230 return err;
231
Herbert Xu6b701dd2006-12-24 09:59:42 +1100232 crypto_cipher_encrypt_one(tfm, key3,
233 (u8 *)(ctx->consts + bs * 2));
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000234
235 ctx->xor(ctx->prev, ctx->odds, bs);
236 ctx->xor(ctx->prev, key3, bs);
237
238 _crypto_xcbc_digest_setkey(parent, ctx);
239
Herbert Xu6b701dd2006-12-24 09:59:42 +1100240 crypto_cipher_encrypt_one(tfm, out, ctx->prev);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000241 }
242
243 return 0;
244}
245
246static int crypto_xcbc_digest(struct hash_desc *pdesc,
247 struct scatterlist *sg, unsigned int nbytes, u8 *out)
248{
Herbert Xufb469842006-12-10 10:45:28 +1100249 if (WARN_ON_ONCE(in_irq()))
250 return -EDEADLK;
251
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000252 crypto_xcbc_digest_init(pdesc);
Herbert Xufb469842006-12-10 10:45:28 +1100253 crypto_xcbc_digest_update2(pdesc, sg, nbytes);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000254 return crypto_xcbc_digest_final(pdesc, out);
255}
256
257static int xcbc_init_tfm(struct crypto_tfm *tfm)
258{
Herbert Xu2e306ee2006-12-17 10:05:58 +1100259 struct crypto_cipher *cipher;
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000260 struct crypto_instance *inst = (void *)tfm->__crt_alg;
261 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
262 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
263 int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm));
264
Herbert Xu2e306ee2006-12-17 10:05:58 +1100265 cipher = crypto_spawn_cipher(spawn);
266 if (IS_ERR(cipher))
267 return PTR_ERR(cipher);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000268
269 switch(bs) {
270 case 16:
271 ctx->xor = xor_128;
272 break;
273 default:
274 return -EINVAL;
275 }
276
Herbert Xu2e306ee2006-12-17 10:05:58 +1100277 ctx->child = cipher;
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000278 ctx->odds = (u8*)(ctx+1);
279 ctx->prev = ctx->odds + bs;
280 ctx->key = ctx->prev + bs;
281
282 return 0;
283};
284
285static void xcbc_exit_tfm(struct crypto_tfm *tfm)
286{
287 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
288 crypto_free_cipher(ctx->child);
289}
290
Herbert Xuebc610e2007-01-01 18:37:02 +1100291static struct crypto_instance *xcbc_alloc(struct rtattr **tb)
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000292{
293 struct crypto_instance *inst;
294 struct crypto_alg *alg;
Herbert Xuebc610e2007-01-01 18:37:02 +1100295 int err;
296
297 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH);
298 if (err)
299 return ERR_PTR(err);
300
301 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
302 CRYPTO_ALG_TYPE_MASK);
Kazunori MIYAZAWA333b0d72006-10-28 13:15:24 +1000303 if (IS_ERR(alg))
304 return ERR_PTR(PTR_ERR(alg));
305
306 switch(alg->cra_blocksize) {
307 case 16:
308 break;
309 default:
310 return ERR_PTR(PTR_ERR(alg));
311 }
312
313 inst = crypto_alloc_instance("xcbc", alg);
314 if (IS_ERR(inst))
315 goto out_put_alg;
316
317 inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
318 inst->alg.cra_priority = alg->cra_priority;
319 inst->alg.cra_blocksize = alg->cra_blocksize;
320 inst->alg.cra_alignmask = alg->cra_alignmask;
321 inst->alg.cra_type = &crypto_hash_type;
322
323 inst->alg.cra_hash.digestsize =
324 (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
325 CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize :
326 alg->cra_blocksize;
327 inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
328 ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *));
329 inst->alg.cra_init = xcbc_init_tfm;
330 inst->alg.cra_exit = xcbc_exit_tfm;
331
332 inst->alg.cra_hash.init = crypto_xcbc_digest_init;
333 inst->alg.cra_hash.update = crypto_xcbc_digest_update;
334 inst->alg.cra_hash.final = crypto_xcbc_digest_final;
335 inst->alg.cra_hash.digest = crypto_xcbc_digest;
336 inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey;
337
338out_put_alg:
339 crypto_mod_put(alg);
340 return inst;
341}
342
343static void xcbc_free(struct crypto_instance *inst)
344{
345 crypto_drop_spawn(crypto_instance_ctx(inst));
346 kfree(inst);
347}
348
349static struct crypto_template crypto_xcbc_tmpl = {
350 .name = "xcbc",
351 .alloc = xcbc_alloc,
352 .free = xcbc_free,
353 .module = THIS_MODULE,
354};
355
356static int __init crypto_xcbc_module_init(void)
357{
358 return crypto_register_template(&crypto_xcbc_tmpl);
359}
360
361static void __exit crypto_xcbc_module_exit(void)
362{
363 crypto_unregister_template(&crypto_xcbc_tmpl);
364}
365
366module_init(crypto_xcbc_module_init);
367module_exit(crypto_xcbc_module_exit);
368
369MODULE_LICENSE("GPL");
370MODULE_DESCRIPTION("XCBC keyed hash algorithm");