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>
26 static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
27 0x02020202, 0x02020202, 0x02020202, 0x02020202,
28 0x03030303, 0x03030303, 0x03030303, 0x03030303};
30 * +------------------------
32 * +------------------------
34 * +------------------------
36 * +------------------------
38 * +------------------------
40 * +------------------------
41 * | consts (block size * 3)
42 * +------------------------
44 struct crypto_xcbc_ctx {
45 struct crypto_cipher *child;
50 void (*xor)(u8 *a, const u8 *b, unsigned int bs);
55 static void xor_128(u8 *a, const u8 *b, unsigned int bs)
57 ((u32 *)a)[0] ^= ((u32 *)b)[0];
58 ((u32 *)a)[1] ^= ((u32 *)b)[1];
59 ((u32 *)a)[2] ^= ((u32 *)b)[2];
60 ((u32 *)a)[3] ^= ((u32 *)b)[3];
63 static int _crypto_xcbc_digest_setkey(struct crypto_shash *parent,
64 struct crypto_xcbc_ctx *ctx)
66 int bs = crypto_shash_blocksize(parent);
70 if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
73 crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts);
75 return crypto_cipher_setkey(ctx->child, key1, bs);
78 static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
79 const u8 *inkey, unsigned int keylen)
81 struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
83 if (keylen != crypto_cipher_blocksize(ctx->child))
87 memcpy(ctx->key, inkey, keylen);
88 ctx->consts = (u8*)ks;
90 return _crypto_xcbc_digest_setkey(parent, ctx);
93 static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
95 struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(pdesc->tfm);
96 int bs = crypto_shash_blocksize(pdesc->tfm);
99 memset(ctx->odds, 0, bs);
100 memset(ctx->prev, 0, bs);
105 static int crypto_xcbc_digest_update(struct shash_desc *pdesc, const u8 *p,
108 struct crypto_shash *parent = pdesc->tfm;
109 struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
110 struct crypto_cipher *tfm = ctx->child;
111 int bs = crypto_shash_blocksize(parent);
113 /* checking the data can fill the block */
114 if ((ctx->len + len) <= bs) {
115 memcpy(ctx->odds + ctx->len, p, len);
120 /* filling odds with new data and encrypting it */
121 memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
122 len -= bs - ctx->len;
125 ctx->xor(ctx->prev, ctx->odds, bs);
126 crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
128 /* clearing the length */
131 /* encrypting the rest of data */
133 ctx->xor(ctx->prev, p, bs);
134 crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
139 /* keeping the surplus of blocksize */
141 memcpy(ctx->odds, p, len);
148 static int crypto_xcbc_digest_final(struct shash_desc *pdesc, u8 *out)
150 struct crypto_shash *parent = pdesc->tfm;
151 struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
152 struct crypto_cipher *tfm = ctx->child;
153 int bs = crypto_shash_blocksize(parent);
156 if (ctx->len == bs) {
159 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
162 crypto_cipher_encrypt_one(tfm, key2,
163 (u8 *)(ctx->consts + bs));
165 ctx->xor(ctx->prev, ctx->odds, bs);
166 ctx->xor(ctx->prev, key2, bs);
167 _crypto_xcbc_digest_setkey(parent, ctx);
169 crypto_cipher_encrypt_one(tfm, out, ctx->prev);
173 u8 *p = ctx->odds + ctx->len;
177 rlen = bs - ctx->len -1;
181 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
184 crypto_cipher_encrypt_one(tfm, key3,
185 (u8 *)(ctx->consts + bs * 2));
187 ctx->xor(ctx->prev, ctx->odds, bs);
188 ctx->xor(ctx->prev, key3, bs);
190 _crypto_xcbc_digest_setkey(parent, ctx);
192 crypto_cipher_encrypt_one(tfm, out, ctx->prev);
198 static int xcbc_init_tfm(struct crypto_tfm *tfm)
200 struct crypto_cipher *cipher;
201 struct crypto_instance *inst = (void *)tfm->__crt_alg;
202 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
203 struct crypto_xcbc_ctx *ctx = crypto_tfm_ctx(tfm);
204 int bs = crypto_tfm_alg_blocksize(tfm);
206 cipher = crypto_spawn_cipher(spawn);
208 return PTR_ERR(cipher);
219 ctx->odds = (u8*)(ctx+1);
220 ctx->prev = ctx->odds + bs;
221 ctx->key = ctx->prev + bs;
226 static void xcbc_exit_tfm(struct crypto_tfm *tfm)
228 struct crypto_xcbc_ctx *ctx = crypto_tfm_ctx(tfm);
229 crypto_free_cipher(ctx->child);
232 static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb)
234 struct shash_instance *inst;
235 struct crypto_alg *alg;
238 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
242 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
243 CRYPTO_ALG_TYPE_MASK);
247 switch(alg->cra_blocksize) {
254 inst = shash_alloc_instance("xcbc", alg);
259 err = crypto_init_spawn(shash_instance_ctx(inst), alg,
260 shash_crypto_instance(inst),
261 CRYPTO_ALG_TYPE_MASK);
265 inst->alg.base.cra_priority = alg->cra_priority;
266 inst->alg.base.cra_blocksize = alg->cra_blocksize;
267 inst->alg.base.cra_alignmask = alg->cra_alignmask;
269 inst->alg.digestsize = alg->cra_blocksize;
270 inst->alg.base.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
271 ALIGN(alg->cra_blocksize * 3,
273 inst->alg.base.cra_init = xcbc_init_tfm;
274 inst->alg.base.cra_exit = xcbc_exit_tfm;
276 inst->alg.init = crypto_xcbc_digest_init;
277 inst->alg.update = crypto_xcbc_digest_update;
278 inst->alg.final = crypto_xcbc_digest_final;
279 inst->alg.setkey = crypto_xcbc_digest_setkey;
281 err = shash_register_instance(tmpl, inst);
284 shash_free_instance(shash_crypto_instance(inst));
292 static struct crypto_template crypto_xcbc_tmpl = {
294 .create = xcbc_create,
295 .free = shash_free_instance,
296 .module = THIS_MODULE,
299 static int __init crypto_xcbc_module_init(void)
301 return crypto_register_template(&crypto_xcbc_tmpl);
304 static void __exit crypto_xcbc_module_exit(void)
306 crypto_unregister_template(&crypto_xcbc_tmpl);
309 module_init(crypto_xcbc_module_init);
310 module_exit(crypto_xcbc_module_exit);
312 MODULE_LICENSE("GPL");
313 MODULE_DESCRIPTION("XCBC keyed hash algorithm");