[net-next-2.6.git] / crypto / xcbc.c

/*
 * Copyright (C)2006 USAGI/WIDE Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author:
 * 	Kazunori Miyazawa <miyazawa@linux-ipv6.org>
 */

#include <crypto/internal/hash.h>
#include <linux/err.h>
#include <linux/kernel.h>

static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
			   0x02020202, 0x02020202, 0x02020202, 0x02020202,
			   0x03030303, 0x03030303, 0x03030303, 0x03030303};
/*
 * +------------------------
 * | <parent tfm>
 * +------------------------
 * | crypto_xcbc_ctx
 * +------------------------
 * | odds (block size)
 * +------------------------
 * | prev (block size)
 * +------------------------
 * | key (block size)
 * +------------------------
 * | consts (block size * 3)
 * +------------------------
 */
struct crypto_xcbc_ctx {
	struct crypto_cipher *child;
	u8 *odds;
	u8 *prev;
	u8 *key;
	u8 *consts;
	unsigned int keylen;
	unsigned int len;
};

static int _crypto_xcbc_digest_setkey(struct crypto_shash *parent,
				      struct crypto_xcbc_ctx *ctx)
{
	int bs = crypto_shash_blocksize(parent);
	int err = 0;
	u8 key1[bs];

	if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
	    return err;

	crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts);

	return crypto_cipher_setkey(ctx->child, key1, bs);
}

static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
				     const u8 *inkey, unsigned int keylen)
{
	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);

	if (keylen != crypto_cipher_blocksize(ctx->child))
		return -EINVAL;

	ctx->keylen = keylen;
	memcpy(ctx->key, inkey, keylen);
	ctx->consts = (u8*)ks;

	return _crypto_xcbc_digest_setkey(parent, ctx);
}

static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
{
	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(pdesc->tfm);
	int bs = crypto_shash_blocksize(pdesc->tfm);

	ctx->len = 0;
	memset(ctx->odds, 0, bs);
	memset(ctx->prev, 0, bs);

	return 0;
}

static int crypto_xcbc_digest_update(struct shash_desc *pdesc, const u8 *p,
				     unsigned int len)
{
	struct crypto_shash *parent = pdesc->tfm;
	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
	struct crypto_cipher *tfm = ctx->child;
	int bs = crypto_shash_blocksize(parent);

	/* checking the data can fill the block */
	if ((ctx->len + len) <= bs) {
		memcpy(ctx->odds + ctx->len, p, len);
		ctx->len += len;
		return 0;
	}

	/* filling odds with new data and encrypting it */
	memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
	len -= bs - ctx->len;
	p += bs - ctx->len;

	crypto_xor(ctx->prev, ctx->odds, bs);
	crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);

	/* clearing the length */
	ctx->len = 0;

	/* encrypting the rest of data */
	while (len > bs) {
		crypto_xor(ctx->prev, p, bs);
		crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
		p += bs;
		len -= bs;
	}

	/* keeping the surplus of blocksize */
	if (len) {
		memcpy(ctx->odds, p, len);
		ctx->len = len;
	}

	return 0;
}

static int crypto_xcbc_digest_final(struct shash_desc *pdesc, u8 *out)
{
	struct crypto_shash *parent = pdesc->tfm;
	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
	struct crypto_cipher *tfm = ctx->child;
	int bs = crypto_shash_blocksize(parent);
	int err = 0;

	if (ctx->len == bs) {
		u8 key2[bs];

		if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
			return err;

		crypto_cipher_encrypt_one(tfm, key2,
					  (u8 *)(ctx->consts + bs));

		crypto_xor(ctx->prev, ctx->odds, bs);
		crypto_xor(ctx->prev, key2, bs);
		_crypto_xcbc_digest_setkey(parent, ctx);

		crypto_cipher_encrypt_one(tfm, out, ctx->prev);
	} else {
		u8 key3[bs];
		unsigned int rlen;
		u8 *p = ctx->odds + ctx->len;
		*p = 0x80;
		p++;

		rlen = bs - ctx->len -1;
		if (rlen)
			memset(p, 0, rlen);

		if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
			return err;

		crypto_cipher_encrypt_one(tfm, key3,
					  (u8 *)(ctx->consts + bs * 2));

		crypto_xor(ctx->prev, ctx->odds, bs);
		crypto_xor(ctx->prev, key3, bs);

		_crypto_xcbc_digest_setkey(parent, ctx);

		crypto_cipher_encrypt_one(tfm, out, ctx->prev);
	}

	return 0;
}

static int xcbc_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_cipher *cipher;
	struct crypto_instance *inst = (void *)tfm->__crt_alg;
	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	struct crypto_xcbc_ctx *ctx = crypto_tfm_ctx(tfm);
	int bs = crypto_tfm_alg_blocksize(tfm);

	cipher = crypto_spawn_cipher(spawn);
	if (IS_ERR(cipher))
		return PTR_ERR(cipher);

	switch(bs) {
	case 16:
		break;
	default:
		return -EINVAL;
	}

	ctx->child = cipher;
	ctx->odds = (u8*)(ctx+1);
	ctx->prev = ctx->odds + bs;
	ctx->key = ctx->prev + bs;

	return 0;
};

static void xcbc_exit_tfm(struct crypto_tfm *tfm)
{
	struct crypto_xcbc_ctx *ctx = crypto_tfm_ctx(tfm);
	crypto_free_cipher(ctx->child);
}

static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb)
{
	struct shash_instance *inst;
	struct crypto_alg *alg;
	int err;

	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
	if (err)
		return err;

	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
				  CRYPTO_ALG_TYPE_MASK);
	if (IS_ERR(alg))
		return PTR_ERR(alg);

	switch(alg->cra_blocksize) {
	case 16:
		break;
	default:
		goto out_put_alg;
	}

	inst = shash_alloc_instance("xcbc", alg);
	err = PTR_ERR(inst);
	if (IS_ERR(inst))
		goto out_put_alg;

	err = crypto_init_spawn(shash_instance_ctx(inst), alg,
				shash_crypto_instance(inst),
				CRYPTO_ALG_TYPE_MASK);
	if (err)
		goto out_free_inst;

	inst->alg.base.cra_priority = alg->cra_priority;
	inst->alg.base.cra_blocksize = alg->cra_blocksize;
	inst->alg.base.cra_alignmask = alg->cra_alignmask;

	inst->alg.digestsize = alg->cra_blocksize;
	inst->alg.base.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
				     ALIGN(alg->cra_blocksize * 3,
					   sizeof(void *));
	inst->alg.base.cra_init = xcbc_init_tfm;
	inst->alg.base.cra_exit = xcbc_exit_tfm;

	inst->alg.init = crypto_xcbc_digest_init;
	inst->alg.update = crypto_xcbc_digest_update;
	inst->alg.final = crypto_xcbc_digest_final;
	inst->alg.setkey = crypto_xcbc_digest_setkey;

	err = shash_register_instance(tmpl, inst);
	if (err) {
out_free_inst:
		shash_free_instance(shash_crypto_instance(inst));
	}

out_put_alg:
	crypto_mod_put(alg);
	return err;
}

static struct crypto_template crypto_xcbc_tmpl = {
	.name = "xcbc",
	.create = xcbc_create,
	.free = shash_free_instance,
	.module = THIS_MODULE,
};

static int __init crypto_xcbc_module_init(void)
{
	return crypto_register_template(&crypto_xcbc_tmpl);
}

static void __exit crypto_xcbc_module_exit(void)
{
	crypto_unregister_template(&crypto_xcbc_tmpl);
}

module_init(crypto_xcbc_module_init);
module_exit(crypto_xcbc_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("XCBC keyed hash algorithm");
Commit	Line	Data
333b0d7e KM	1	/*
	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
3106caab	22	#include <crypto/internal/hash.h>
333b0d7e KM	23	#include <linux/err.h>
333b0d7e KM	24	#include <linux/kernel.h>
333b0d7e	25
5b37538a AB	26	static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
	27	0x02020202, 0x02020202, 0x02020202, 0x02020202,
	28	0x03030303, 0x03030303, 0x03030303, 0x03030303};
333b0d7e KM	29	/*
	30	* +------------------------
	31	* \| <parent tfm>
	32	* +------------------------
	33	* \| crypto_xcbc_ctx
	34	* +------------------------
	35	* \| odds (block size)
	36	* +------------------------
	37	* \| prev (block size)
	38	* +------------------------
	39	* \| key (block size)
	40	* +------------------------
	41	* \| consts (block size * 3)
	42	* +------------------------
	43	*/
	44	struct crypto_xcbc_ctx {
6b701dde	45	struct crypto_cipher *child;
333b0d7e KM	46	u8 *odds;
	47	u8 *prev;
	48	u8 *key;
	49	u8 *consts;
333b0d7e KM	50	unsigned int keylen;
	51	unsigned int len;
	52	};
	53
3106caab	54	static int _crypto_xcbc_digest_setkey(struct crypto_shash *parent,
333b0d7e KM	55	struct crypto_xcbc_ctx *ctx)
333b0d7e KM	56	{
3106caab	57	int bs = crypto_shash_blocksize(parent);
333b0d7e KM	58	int err = 0;
	59	u8 key1[bs];
	60
	61	if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
	62	return err;
	63
6b701dde	64	crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts);
333b0d7e KM	65
	66	return crypto_cipher_setkey(ctx->child, key1, bs);
	67	}
	68
3106caab	69	static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
333b0d7e KM	70	const u8 *inkey, unsigned int keylen)
333b0d7e KM	71	{
3106caab	72	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
333b0d7e	73
6b701dde	74	if (keylen != crypto_cipher_blocksize(ctx->child))
333b0d7e KM	75	return -EINVAL;
	76
	77	ctx->keylen = keylen;
	78	memcpy(ctx->key, inkey, keylen);
	79	ctx->consts = (u8*)ks;
	80
	81	return _crypto_xcbc_digest_setkey(parent, ctx);
	82	}
	83
3106caab	84	static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
333b0d7e	85	{
3106caab HX	86	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(pdesc->tfm);
3106caab HX	87	int bs = crypto_shash_blocksize(pdesc->tfm);
333b0d7e KM	88
	89	ctx->len = 0;
	90	memset(ctx->odds, 0, bs);
	91	memset(ctx->prev, 0, bs);
	92
	93	return 0;
	94	}
	95
3106caab HX	96	static int crypto_xcbc_digest_update(struct shash_desc pdesc, const u8 p,
3106caab HX	97	unsigned int len)
333b0d7e	98	{
3106caab HX	99	struct crypto_shash *parent = pdesc->tfm;
3106caab HX	100	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
6b701dde	101	struct crypto_cipher *tfm = ctx->child;
3106caab HX	102	int bs = crypto_shash_blocksize(parent);
	103
	104	/* checking the data can fill the block */
	105	if ((ctx->len + len) <= bs) {
	106	memcpy(ctx->odds + ctx->len, p, len);
	107	ctx->len += len;
	108	return 0;
1edcf2e1	109	}
333b0d7e	110
3106caab HX	111	/* filling odds with new data and encrypting it */
	112	memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
	113	len -= bs - ctx->len;
	114	p += bs - ctx->len;
333b0d7e	115
b588ef6e	116	crypto_xor(ctx->prev, ctx->odds, bs);
3106caab HX	117	crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
	118
	119	/* clearing the length */
	120	ctx->len = 0;
	121
	122	/* encrypting the rest of data */
	123	while (len > bs) {
b588ef6e	124	crypto_xor(ctx->prev, p, bs);
3106caab HX	125	crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
	126	p += bs;
	127	len -= bs;
	128	}
	129
	130	/* keeping the surplus of blocksize */
	131	if (len) {
	132	memcpy(ctx->odds, p, len);
	133	ctx->len = len;
	134	}
	135
	136	return 0;
fb469840 HX	137	}
fb469840 HX	138
3106caab	139	static int crypto_xcbc_digest_final(struct shash_desc pdesc, u8 out)
333b0d7e	140	{
3106caab HX	141	struct crypto_shash *parent = pdesc->tfm;
3106caab HX	142	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
6b701dde	143	struct crypto_cipher *tfm = ctx->child;
3106caab	144	int bs = crypto_shash_blocksize(parent);
333b0d7e KM	145	int err = 0;
	146
	147	if (ctx->len == bs) {
	148	u8 key2[bs];
	149
	150	if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	151	return err;
	152
6b701dde HX	153	crypto_cipher_encrypt_one(tfm, key2,
6b701dde HX	154	(u8 *)(ctx->consts + bs));
333b0d7e	155
b588ef6e HX	156	crypto_xor(ctx->prev, ctx->odds, bs);
b588ef6e HX	157	crypto_xor(ctx->prev, key2, bs);
333b0d7e KM	158	_crypto_xcbc_digest_setkey(parent, ctx);
333b0d7e KM	159
6b701dde	160	crypto_cipher_encrypt_one(tfm, out, ctx->prev);
333b0d7e KM	161	} else {
	162	u8 key3[bs];
	163	unsigned int rlen;
	164	u8 *p = ctx->odds + ctx->len;
	165	*p = 0x80;
	166	p++;
	167
	168	rlen = bs - ctx->len -1;
	169	if (rlen)
	170	memset(p, 0, rlen);
	171
	172	if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	173	return err;
	174
6b701dde HX	175	crypto_cipher_encrypt_one(tfm, key3,
6b701dde HX	176	(u8 )(ctx->consts + bs 2));
333b0d7e	177
b588ef6e HX	178	crypto_xor(ctx->prev, ctx->odds, bs);
b588ef6e HX	179	crypto_xor(ctx->prev, key3, bs);
333b0d7e KM	180
	181	_crypto_xcbc_digest_setkey(parent, ctx);
	182
6b701dde	183	crypto_cipher_encrypt_one(tfm, out, ctx->prev);
333b0d7e KM	184	}
	185
	186	return 0;
	187	}
	188
333b0d7e KM	189	static int xcbc_init_tfm(struct crypto_tfm *tfm)
333b0d7e KM	190	{
2e306ee0	191	struct crypto_cipher *cipher;
333b0d7e KM	192	struct crypto_instance inst = (void )tfm->__crt_alg;
333b0d7e KM	193	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
3106caab HX	194	struct crypto_xcbc_ctx *ctx = crypto_tfm_ctx(tfm);
3106caab HX	195	int bs = crypto_tfm_alg_blocksize(tfm);
333b0d7e	196
2e306ee0 HX	197	cipher = crypto_spawn_cipher(spawn);
	198	if (IS_ERR(cipher))
	199	return PTR_ERR(cipher);
333b0d7e KM	200
	201	switch(bs) {
	202	case 16:
333b0d7e KM	203	break;
	204	default:
	205	return -EINVAL;
	206	}
	207
2e306ee0	208	ctx->child = cipher;
333b0d7e KM	209	ctx->odds = (u8*)(ctx+1);
	210	ctx->prev = ctx->odds + bs;
	211	ctx->key = ctx->prev + bs;
	212
	213	return 0;
	214	};
	215
	216	static void xcbc_exit_tfm(struct crypto_tfm *tfm)
	217	{
3106caab	218	struct crypto_xcbc_ctx *ctx = crypto_tfm_ctx(tfm);
333b0d7e KM	219	crypto_free_cipher(ctx->child);
	220	}
	221
3106caab	222	static int xcbc_create(struct crypto_template tmpl, struct rtattr *tb)
333b0d7e	223	{
3106caab	224	struct shash_instance *inst;
333b0d7e	225	struct crypto_alg *alg;
ebc610e5 HX	226	int err;
ebc610e5 HX	227
3106caab	228	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
ebc610e5	229	if (err)
3106caab	230	return err;
ebc610e5 HX	231
	232	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
	233	CRYPTO_ALG_TYPE_MASK);
333b0d7e	234	if (IS_ERR(alg))
3106caab	235	return PTR_ERR(alg);
333b0d7e KM	236
	237	switch(alg->cra_blocksize) {
	238	case 16:
	239	break;
	240	default:
1b87887d	241	goto out_put_alg;
333b0d7e KM	242	}
333b0d7e KM	243
3106caab	244	inst = shash_alloc_instance("xcbc", alg);
b5ebd44e	245	err = PTR_ERR(inst);
333b0d7e KM	246	if (IS_ERR(inst))
	247	goto out_put_alg;
	248
3106caab HX	249	err = crypto_init_spawn(shash_instance_ctx(inst), alg,
	250	shash_crypto_instance(inst),
	251	CRYPTO_ALG_TYPE_MASK);
	252	if (err)
	253	goto out_free_inst;
	254
	255	inst->alg.base.cra_priority = alg->cra_priority;
	256	inst->alg.base.cra_blocksize = alg->cra_blocksize;
	257	inst->alg.base.cra_alignmask = alg->cra_alignmask;
	258
	259	inst->alg.digestsize = alg->cra_blocksize;
	260	inst->alg.base.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
	261	ALIGN(alg->cra_blocksize * 3,
	262	sizeof(void *));
	263	inst->alg.base.cra_init = xcbc_init_tfm;
	264	inst->alg.base.cra_exit = xcbc_exit_tfm;
	265
	266	inst->alg.init = crypto_xcbc_digest_init;
	267	inst->alg.update = crypto_xcbc_digest_update;
	268	inst->alg.final = crypto_xcbc_digest_final;
	269	inst->alg.setkey = crypto_xcbc_digest_setkey;
	270
	271	err = shash_register_instance(tmpl, inst);
	272	if (err) {
	273	out_free_inst:
	274	shash_free_instance(shash_crypto_instance(inst));
	275	}
333b0d7e KM	276
	277	out_put_alg:
	278	crypto_mod_put(alg);
3106caab	279	return err;
333b0d7e KM	280	}
	281
	282	static struct crypto_template crypto_xcbc_tmpl = {
	283	.name = "xcbc",
3106caab HX	284	.create = xcbc_create,
3106caab HX	285	.free = shash_free_instance,
333b0d7e KM	286	.module = THIS_MODULE,
	287	};
	288
	289	static int __init crypto_xcbc_module_init(void)
	290	{
	291	return crypto_register_template(&crypto_xcbc_tmpl);
	292	}
	293
	294	static void __exit crypto_xcbc_module_exit(void)
	295	{
	296	crypto_unregister_template(&crypto_xcbc_tmpl);
	297	}
	298
	299	module_init(crypto_xcbc_module_init);
	300	module_exit(crypto_xcbc_module_exit);
	301
	302	MODULE_LICENSE("GPL");
	303	MODULE_DESCRIPTION("XCBC keyed hash algorithm");