2 * Copyright (C)2006 USAGI/WIDE Project
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.
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.
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
19 * Kazunori Miyazawa <miyazawa@linux-ipv6.org>
22 #include <crypto/internal/hash.h>
23 #include <linux/err.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
27 static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
28 0x02020202, 0x02020202, 0x02020202, 0x02020202,
29 0x03030303, 0x03030303, 0x03030303, 0x03030303};
32 * +------------------------
34 * +------------------------
36 * +------------------------
37 * | consts (block size * 2)
38 * +------------------------
41 struct crypto_cipher *child;
46 * +------------------------
48 * +------------------------
50 * +------------------------
52 * +------------------------
54 * +------------------------
56 struct xcbc_desc_ctx {
61 static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
62 const u8 *inkey, unsigned int keylen)
64 unsigned long alignmask = crypto_shash_alignmask(parent);
65 struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent);
66 int bs = crypto_shash_blocksize(parent);
67 u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
71 if ((err = crypto_cipher_setkey(ctx->child, inkey, keylen)))
74 crypto_cipher_encrypt_one(ctx->child, consts, (u8 *)ks + bs);
75 crypto_cipher_encrypt_one(ctx->child, consts + bs, (u8 *)ks + bs * 2);
76 crypto_cipher_encrypt_one(ctx->child, key1, (u8 *)ks);
78 return crypto_cipher_setkey(ctx->child, key1, bs);
82 static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
84 unsigned long alignmask = crypto_shash_alignmask(pdesc->tfm);
85 struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
86 int bs = crypto_shash_blocksize(pdesc->tfm);
87 u8 *prev = PTR_ALIGN(&ctx->ctx[0], alignmask + 1) + bs;
95 static int crypto_xcbc_digest_update(struct shash_desc *pdesc, const u8 *p,
98 struct crypto_shash *parent = pdesc->tfm;
99 unsigned long alignmask = crypto_shash_alignmask(parent);
100 struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);
101 struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
102 struct crypto_cipher *tfm = tctx->child;
103 int bs = crypto_shash_blocksize(parent);
104 u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
105 u8 *prev = odds + bs;
107 /* checking the data can fill the block */
108 if ((ctx->len + len) <= bs) {
109 memcpy(odds + ctx->len, p, len);
114 /* filling odds with new data and encrypting it */
115 memcpy(odds + ctx->len, p, bs - ctx->len);
116 len -= bs - ctx->len;
119 crypto_xor(prev, odds, bs);
120 crypto_cipher_encrypt_one(tfm, prev, prev);
122 /* clearing the length */
125 /* encrypting the rest of data */
127 crypto_xor(prev, p, bs);
128 crypto_cipher_encrypt_one(tfm, prev, prev);
133 /* keeping the surplus of blocksize */
135 memcpy(odds, p, len);
142 static int crypto_xcbc_digest_final(struct shash_desc *pdesc, u8 *out)
144 struct crypto_shash *parent = pdesc->tfm;
145 unsigned long alignmask = crypto_shash_alignmask(parent);
146 struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);
147 struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
148 struct crypto_cipher *tfm = tctx->child;
149 int bs = crypto_shash_blocksize(parent);
150 u8 *consts = PTR_ALIGN(&tctx->ctx[0], alignmask + 1);
151 u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
152 u8 *prev = odds + bs;
153 unsigned int offset = 0;
155 if (ctx->len != bs) {
157 u8 *p = odds + ctx->len;
162 rlen = bs - ctx->len -1;
169 crypto_xor(prev, odds, bs);
170 crypto_xor(prev, consts + offset, bs);
172 crypto_cipher_encrypt_one(tfm, out, prev);
177 static int xcbc_init_tfm(struct crypto_tfm *tfm)
179 struct crypto_cipher *cipher;
180 struct crypto_instance *inst = (void *)tfm->__crt_alg;
181 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
182 struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
184 cipher = crypto_spawn_cipher(spawn);
186 return PTR_ERR(cipher);
193 static void xcbc_exit_tfm(struct crypto_tfm *tfm)
195 struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
196 crypto_free_cipher(ctx->child);
199 static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb)
201 struct shash_instance *inst;
202 struct crypto_alg *alg;
203 unsigned long alignmask;
206 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
210 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
211 CRYPTO_ALG_TYPE_MASK);
215 switch(alg->cra_blocksize) {
222 inst = shash_alloc_instance("xcbc", alg);
227 err = crypto_init_spawn(shash_instance_ctx(inst), alg,
228 shash_crypto_instance(inst),
229 CRYPTO_ALG_TYPE_MASK);
233 alignmask = alg->cra_alignmask | 3;
234 inst->alg.base.cra_alignmask = alignmask;
235 inst->alg.base.cra_priority = alg->cra_priority;
236 inst->alg.base.cra_blocksize = alg->cra_blocksize;
238 inst->alg.digestsize = alg->cra_blocksize;
239 inst->alg.descsize = ALIGN(sizeof(struct xcbc_desc_ctx),
240 crypto_tfm_ctx_alignment()) +
242 ~(crypto_tfm_ctx_alignment() - 1)) +
243 alg->cra_blocksize * 2;
245 inst->alg.base.cra_ctxsize = ALIGN(sizeof(struct xcbc_tfm_ctx),
247 alg->cra_blocksize * 2;
248 inst->alg.base.cra_init = xcbc_init_tfm;
249 inst->alg.base.cra_exit = xcbc_exit_tfm;
251 inst->alg.init = crypto_xcbc_digest_init;
252 inst->alg.update = crypto_xcbc_digest_update;
253 inst->alg.final = crypto_xcbc_digest_final;
254 inst->alg.setkey = crypto_xcbc_digest_setkey;
256 err = shash_register_instance(tmpl, inst);
259 shash_free_instance(shash_crypto_instance(inst));
267 static struct crypto_template crypto_xcbc_tmpl = {
269 .create = xcbc_create,
270 .free = shash_free_instance,
271 .module = THIS_MODULE,
274 static int __init crypto_xcbc_module_init(void)
276 return crypto_register_template(&crypto_xcbc_tmpl);
279 static void __exit crypto_xcbc_module_exit(void)
281 crypto_unregister_template(&crypto_xcbc_tmpl);
284 module_init(crypto_xcbc_module_init);
285 module_exit(crypto_xcbc_module_exit);
287 MODULE_LICENSE("GPL");
288 MODULE_DESCRIPTION("XCBC keyed hash algorithm");