[linux-2.6-block.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>
 * +------------------------
 * | xcbc_tfm_ctx
 * +------------------------
 * | consts (block size * 2)
 * +------------------------
 */
struct xcbc_tfm_ctx {
	struct crypto_cipher *child;
	u8 ctx[];
};

/*
 * +------------------------
 * | <shash desc>
 * +------------------------
 * | xcbc_desc_ctx
 * +------------------------
 * | odds (block size)
 * +------------------------
 * | prev (block size)
 * +------------------------
 */
struct xcbc_desc_ctx {
	unsigned int len;
	u8 ctx[];
};

static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
				     const u8 *inkey, unsigned int keylen)
{
	unsigned long alignmask = crypto_shash_alignmask(parent);
	struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent);
	int bs = crypto_shash_blocksize(parent);
	u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
	int err = 0;
	u8 key1[bs];

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

	crypto_cipher_encrypt_one(ctx->child, consts, (u8 *)ks + bs);
	crypto_cipher_encrypt_one(ctx->child, consts + bs, (u8 *)ks + bs * 2);
	crypto_cipher_encrypt_one(ctx->child, key1, (u8 *)ks);

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

}

static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
{
	unsigned long alignmask = crypto_shash_alignmask(pdesc->tfm);
	struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
	int bs = crypto_shash_blocksize(pdesc->tfm);
	u8 *prev = PTR_ALIGN(&ctx->ctx[0], alignmask + 1) + bs;

	ctx->len = 0;
	memset(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;
	unsigned long alignmask = crypto_shash_alignmask(parent);
	struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);
	struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
	struct crypto_cipher *tfm = tctx->child;
	int bs = crypto_shash_blocksize(parent);
	u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
	u8 *prev = odds + bs;

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

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

	crypto_xor(prev, odds, bs);
	crypto_cipher_encrypt_one(tfm, prev, prev);

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

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

	/* keeping the surplus of blocksize */
	if (len) {
		memcpy(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;
	unsigned long alignmask = crypto_shash_alignmask(parent);
	struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);
	struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
	struct crypto_cipher *tfm = tctx->child;
	int bs = crypto_shash_blocksize(parent);
	u8 *consts = PTR_ALIGN(&tctx->ctx[0], alignmask + 1);
	u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
	u8 *prev = odds + bs;
	unsigned int offset = 0;

	if (ctx->len != bs) {
		unsigned int rlen;
		u8 *p = odds + ctx->len;

		*p = 0x80;
		p++;

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

		offset += bs;
	}

	crypto_xor(prev, odds, bs);
	crypto_xor(prev, consts + offset, bs);

	crypto_cipher_encrypt_one(tfm, out, 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 xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);

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

	ctx->child = cipher;

	return 0;
};

static void xcbc_exit_tfm(struct crypto_tfm *tfm)
{
	struct xcbc_tfm_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;
	unsigned long alignmask;
	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;

	alignmask = alg->cra_alignmask | 3;
	inst->alg.base.cra_alignmask = alignmask;
	inst->alg.base.cra_priority = alg->cra_priority;
	inst->alg.base.cra_blocksize = alg->cra_blocksize;

	inst->alg.digestsize = alg->cra_blocksize;
	inst->alg.descsize = ALIGN(sizeof(struct xcbc_desc_ctx),
				   crypto_tfm_ctx_alignment()) +
			     (alignmask &
			      ~(crypto_tfm_ctx_alignment() - 1)) +
			     alg->cra_blocksize * 2;

	inst->alg.base.cra_ctxsize = ALIGN(sizeof(struct xcbc_tfm_ctx),
					   alignmask + 1) +
				     alg->cra_blocksize * 2;
	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};
ac95301f	29
333b0d7e KM	30	/*
	31	* +------------------------
	32	* \| <parent tfm>
	33	* +------------------------
ac95301f	34	* \| xcbc_tfm_ctx
333b0d7e	35	* +------------------------
ac95301f	36	* \| consts (block size * 2)
333b0d7e	37	* +------------------------
ac95301f HX	38	*/
	39	struct xcbc_tfm_ctx {
	40	struct crypto_cipher *child;
	41	u8 ctx[];
	42	};
	43
	44	/*
333b0d7e	45	* +------------------------
ac95301f	46	* \| <shash desc>
333b0d7e	47	* +------------------------
ac95301f HX	48	* \| xcbc_desc_ctx
	49	* +------------------------
	50	* \| odds (block size)
	51	* +------------------------
	52	* \| prev (block size)
333b0d7e KM	53	* +------------------------
333b0d7e KM	54	*/
ac95301f	55	struct xcbc_desc_ctx {
333b0d7e	56	unsigned int len;
ac95301f	57	u8 ctx[];
333b0d7e KM	58	};
333b0d7e KM	59
ac95301f HX	60	static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
ac95301f HX	61	const u8 *inkey, unsigned int keylen)
333b0d7e	62	{
ac95301f HX	63	unsigned long alignmask = crypto_shash_alignmask(parent);
ac95301f HX	64	struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent);
3106caab	65	int bs = crypto_shash_blocksize(parent);
ac95301f	66	u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
333b0d7e KM	67	int err = 0;
	68	u8 key1[bs];
	69
ac95301f HX	70	if ((err = crypto_cipher_setkey(ctx->child, inkey, keylen)))
ac95301f HX	71	return err;
333b0d7e	72
ac95301f HX	73	crypto_cipher_encrypt_one(ctx->child, consts, (u8 *)ks + bs);
	74	crypto_cipher_encrypt_one(ctx->child, consts + bs, (u8 )ks + bs 2);
	75	crypto_cipher_encrypt_one(ctx->child, key1, (u8 *)ks);
333b0d7e KM	76
333b0d7e KM	77	return crypto_cipher_setkey(ctx->child, key1, bs);
333b0d7e	78
333b0d7e KM	79	}
333b0d7e KM	80
3106caab	81	static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
333b0d7e	82	{
ac95301f HX	83	unsigned long alignmask = crypto_shash_alignmask(pdesc->tfm);
ac95301f HX	84	struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
3106caab	85	int bs = crypto_shash_blocksize(pdesc->tfm);
ac95301f	86	u8 *prev = PTR_ALIGN(&ctx->ctx[0], alignmask + 1) + bs;
333b0d7e KM	87
333b0d7e KM	88	ctx->len = 0;
ac95301f	89	memset(prev, 0, bs);
333b0d7e KM	90
	91	return 0;
	92	}
	93
3106caab HX	94	static int crypto_xcbc_digest_update(struct shash_desc pdesc, const u8 p,
3106caab HX	95	unsigned int len)
333b0d7e	96	{
3106caab	97	struct crypto_shash *parent = pdesc->tfm;
ac95301f HX	98	unsigned long alignmask = crypto_shash_alignmask(parent);
	99	struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);
	100	struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
	101	struct crypto_cipher *tfm = tctx->child;
3106caab	102	int bs = crypto_shash_blocksize(parent);
ac95301f HX	103	u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
ac95301f HX	104	u8 *prev = odds + bs;
3106caab HX	105
	106	/* checking the data can fill the block */
	107	if ((ctx->len + len) <= bs) {
ac95301f	108	memcpy(odds + ctx->len, p, len);
3106caab HX	109	ctx->len += len;
3106caab HX	110	return 0;
1edcf2e1	111	}
333b0d7e	112
3106caab	113	/* filling odds with new data and encrypting it */
ac95301f	114	memcpy(odds + ctx->len, p, bs - ctx->len);
3106caab HX	115	len -= bs - ctx->len;
3106caab HX	116	p += bs - ctx->len;
333b0d7e	117
ac95301f HX	118	crypto_xor(prev, odds, bs);
ac95301f HX	119	crypto_cipher_encrypt_one(tfm, prev, prev);
3106caab HX	120
	121	/* clearing the length */
	122	ctx->len = 0;
	123
	124	/* encrypting the rest of data */
	125	while (len > bs) {
ac95301f HX	126	crypto_xor(prev, p, bs);
ac95301f HX	127	crypto_cipher_encrypt_one(tfm, prev, prev);
3106caab HX	128	p += bs;
	129	len -= bs;
	130	}
	131
	132	/* keeping the surplus of blocksize */
	133	if (len) {
ac95301f	134	memcpy(odds, p, len);
3106caab HX	135	ctx->len = len;
	136	}
	137
	138	return 0;
fb469840 HX	139	}
fb469840 HX	140
3106caab	141	static int crypto_xcbc_digest_final(struct shash_desc pdesc, u8 out)
333b0d7e	142	{
3106caab	143	struct crypto_shash *parent = pdesc->tfm;
ac95301f HX	144	unsigned long alignmask = crypto_shash_alignmask(parent);
	145	struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);
	146	struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
	147	struct crypto_cipher *tfm = tctx->child;
3106caab	148	int bs = crypto_shash_blocksize(parent);
ac95301f HX	149	u8 *consts = PTR_ALIGN(&tctx->ctx[0], alignmask + 1);
	150	u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
	151	u8 *prev = odds + bs;
	152	unsigned int offset = 0;
333b0d7e	153
ac95301f	154	if (ctx->len != bs) {
333b0d7e	155	unsigned int rlen;
ac95301f HX	156	u8 *p = odds + ctx->len;
ac95301f HX	157
333b0d7e KM	158	*p = 0x80;
	159	p++;
	160
	161	rlen = bs - ctx->len -1;
	162	if (rlen)
	163	memset(p, 0, rlen);
	164
ac95301f HX	165	offset += bs;
ac95301f HX	166	}
333b0d7e	167
ac95301f HX	168	crypto_xor(prev, odds, bs);
ac95301f HX	169	crypto_xor(prev, consts + offset, bs);
333b0d7e	170
ac95301f	171	crypto_cipher_encrypt_one(tfm, out, prev);
333b0d7e KM	172
	173	return 0;
	174	}
	175
333b0d7e KM	176	static int xcbc_init_tfm(struct crypto_tfm *tfm)
333b0d7e KM	177	{
2e306ee0	178	struct crypto_cipher *cipher;
333b0d7e KM	179	struct crypto_instance inst = (void )tfm->__crt_alg;
333b0d7e KM	180	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
ac95301f	181	struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
333b0d7e	182
2e306ee0 HX	183	cipher = crypto_spawn_cipher(spawn);
	184	if (IS_ERR(cipher))
	185	return PTR_ERR(cipher);
333b0d7e	186
2e306ee0	187	ctx->child = cipher;
333b0d7e KM	188
	189	return 0;
	190	};
	191
	192	static void xcbc_exit_tfm(struct crypto_tfm *tfm)
	193	{
ac95301f	194	struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
333b0d7e KM	195	crypto_free_cipher(ctx->child);
	196	}
	197
3106caab	198	static int xcbc_create(struct crypto_template tmpl, struct rtattr *tb)
333b0d7e	199	{
3106caab	200	struct shash_instance *inst;
333b0d7e	201	struct crypto_alg *alg;
36f87a4a	202	unsigned long alignmask;
ebc610e5 HX	203	int err;
ebc610e5 HX	204
3106caab	205	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
ebc610e5	206	if (err)
3106caab	207	return err;
ebc610e5 HX	208
	209	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
	210	CRYPTO_ALG_TYPE_MASK);
333b0d7e	211	if (IS_ERR(alg))
3106caab	212	return PTR_ERR(alg);
333b0d7e KM	213
	214	switch(alg->cra_blocksize) {
	215	case 16:
	216	break;
	217	default:
1b87887d	218	goto out_put_alg;
333b0d7e KM	219	}
333b0d7e KM	220
3106caab	221	inst = shash_alloc_instance("xcbc", alg);
b5ebd44e	222	err = PTR_ERR(inst);
333b0d7e KM	223	if (IS_ERR(inst))
	224	goto out_put_alg;
	225
3106caab HX	226	err = crypto_init_spawn(shash_instance_ctx(inst), alg,
	227	shash_crypto_instance(inst),
	228	CRYPTO_ALG_TYPE_MASK);
	229	if (err)
	230	goto out_free_inst;
	231
36f87a4a SK	232	alignmask = alg->cra_alignmask \| 3;
36f87a4a SK	233	inst->alg.base.cra_alignmask = alignmask;
3106caab HX	234	inst->alg.base.cra_priority = alg->cra_priority;
3106caab HX	235	inst->alg.base.cra_blocksize = alg->cra_blocksize;
3106caab HX	236
3106caab HX	237	inst->alg.digestsize = alg->cra_blocksize;
ac95301f HX	238	inst->alg.descsize = ALIGN(sizeof(struct xcbc_desc_ctx),
ac95301f HX	239	crypto_tfm_ctx_alignment()) +
36f87a4a	240	(alignmask &
ac95301f HX	241	~(crypto_tfm_ctx_alignment() - 1)) +
	242	alg->cra_blocksize * 2;
	243
	244	inst->alg.base.cra_ctxsize = ALIGN(sizeof(struct xcbc_tfm_ctx),
36f87a4a	245	alignmask + 1) +
ac95301f	246	alg->cra_blocksize * 2;
3106caab HX	247	inst->alg.base.cra_init = xcbc_init_tfm;
	248	inst->alg.base.cra_exit = xcbc_exit_tfm;
	249
	250	inst->alg.init = crypto_xcbc_digest_init;
	251	inst->alg.update = crypto_xcbc_digest_update;
	252	inst->alg.final = crypto_xcbc_digest_final;
	253	inst->alg.setkey = crypto_xcbc_digest_setkey;
	254
	255	err = shash_register_instance(tmpl, inst);
	256	if (err) {
	257	out_free_inst:
	258	shash_free_instance(shash_crypto_instance(inst));
	259	}
333b0d7e KM	260
	261	out_put_alg:
	262	crypto_mod_put(alg);
3106caab	263	return err;
333b0d7e KM	264	}
	265
	266	static struct crypto_template crypto_xcbc_tmpl = {
	267	.name = "xcbc",
3106caab HX	268	.create = xcbc_create,
3106caab HX	269	.free = shash_free_instance,
333b0d7e KM	270	.module = THIS_MODULE,
	271	};
	272
	273	static int __init crypto_xcbc_module_init(void)
	274	{
	275	return crypto_register_template(&crypto_xcbc_tmpl);
	276	}
	277
	278	static void __exit crypto_xcbc_module_exit(void)
	279	{
	280	crypto_unregister_template(&crypto_xcbc_tmpl);
	281	}
	282
	283	module_init(crypto_xcbc_module_init);
	284	module_exit(crypto_xcbc_module_exit);
	285
	286	MODULE_LICENSE("GPL");
	287	MODULE_DESCRIPTION("XCBC keyed hash algorithm");