[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;
	void (*xor)(u8 *a, const u8 *b, unsigned int bs);
	unsigned int keylen;
	unsigned int len;
};

static void xor_128(u8 *a, const u8 *b, unsigned int bs)
{
	((u32 *)a)[0] ^= ((u32 *)b)[0];
	((u32 *)a)[1] ^= ((u32 *)b)[1];
	((u32 *)a)[2] ^= ((u32 *)b)[2];
	((u32 *)a)[3] ^= ((u32 *)b)[3];
}

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;

	ctx->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) {
		ctx->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));

		ctx->xor(ctx->prev, ctx->odds, bs);
		ctx->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));

		ctx->xor(ctx->prev, ctx->odds, bs);
		ctx->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:
		ctx->xor = xor_128;
		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);
	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;
	50	void (xor)(u8 a, const u8 *b, unsigned int bs);
	51	unsigned int keylen;
	52	unsigned int len;
	53	};
	54
	55	static void xor_128(u8 a, const u8 b, unsigned int bs)
	56	{
	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];
	61	}
	62
3106caab	63	static int _crypto_xcbc_digest_setkey(struct crypto_shash *parent,
333b0d7e KM	64	struct crypto_xcbc_ctx *ctx)
333b0d7e KM	65	{
3106caab	66	int bs = crypto_shash_blocksize(parent);
333b0d7e KM	67	int err = 0;
	68	u8 key1[bs];
	69
	70	if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
	71	return err;
	72
6b701dde	73	crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts);
333b0d7e KM	74
	75	return crypto_cipher_setkey(ctx->child, key1, bs);
	76	}
	77
3106caab	78	static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
333b0d7e KM	79	const u8 *inkey, unsigned int keylen)
333b0d7e KM	80	{
3106caab	81	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
333b0d7e	82
6b701dde	83	if (keylen != crypto_cipher_blocksize(ctx->child))
333b0d7e KM	84	return -EINVAL;
	85
	86	ctx->keylen = keylen;
	87	memcpy(ctx->key, inkey, keylen);
	88	ctx->consts = (u8*)ks;
	89
	90	return _crypto_xcbc_digest_setkey(parent, ctx);
	91	}
	92
3106caab	93	static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
333b0d7e	94	{
3106caab HX	95	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(pdesc->tfm);
3106caab HX	96	int bs = crypto_shash_blocksize(pdesc->tfm);
333b0d7e KM	97
	98	ctx->len = 0;
	99	memset(ctx->odds, 0, bs);
	100	memset(ctx->prev, 0, bs);
	101
	102	return 0;
	103	}
	104
3106caab HX	105	static int crypto_xcbc_digest_update(struct shash_desc pdesc, const u8 p,
3106caab HX	106	unsigned int len)
333b0d7e	107	{
3106caab HX	108	struct crypto_shash *parent = pdesc->tfm;
3106caab HX	109	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
6b701dde	110	struct crypto_cipher *tfm = ctx->child;
3106caab HX	111	int bs = crypto_shash_blocksize(parent);
	112
	113	/* checking the data can fill the block */
	114	if ((ctx->len + len) <= bs) {
	115	memcpy(ctx->odds + ctx->len, p, len);
	116	ctx->len += len;
	117	return 0;
1edcf2e1	118	}
333b0d7e	119
3106caab HX	120	/* filling odds with new data and encrypting it */
	121	memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
	122	len -= bs - ctx->len;
	123	p += bs - ctx->len;
333b0d7e	124
3106caab HX	125	ctx->xor(ctx->prev, ctx->odds, bs);
	126	crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
	127
	128	/* clearing the length */
	129	ctx->len = 0;
	130
	131	/* encrypting the rest of data */
	132	while (len > bs) {
	133	ctx->xor(ctx->prev, p, bs);
	134	crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
	135	p += bs;
	136	len -= bs;
	137	}
	138
	139	/* keeping the surplus of blocksize */
	140	if (len) {
	141	memcpy(ctx->odds, p, len);
	142	ctx->len = len;
	143	}
	144
	145	return 0;
fb469840 HX	146	}
fb469840 HX	147
3106caab	148	static int crypto_xcbc_digest_final(struct shash_desc pdesc, u8 out)
333b0d7e	149	{
3106caab HX	150	struct crypto_shash *parent = pdesc->tfm;
3106caab HX	151	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
6b701dde	152	struct crypto_cipher *tfm = ctx->child;
3106caab	153	int bs = crypto_shash_blocksize(parent);
333b0d7e KM	154	int err = 0;
	155
	156	if (ctx->len == bs) {
	157	u8 key2[bs];
	158
	159	if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	160	return err;
	161
6b701dde HX	162	crypto_cipher_encrypt_one(tfm, key2,
6b701dde HX	163	(u8 *)(ctx->consts + bs));
333b0d7e KM	164
	165	ctx->xor(ctx->prev, ctx->odds, bs);
	166	ctx->xor(ctx->prev, key2, bs);
	167	_crypto_xcbc_digest_setkey(parent, ctx);
	168
6b701dde	169	crypto_cipher_encrypt_one(tfm, out, ctx->prev);
333b0d7e KM	170	} else {
	171	u8 key3[bs];
	172	unsigned int rlen;
	173	u8 *p = ctx->odds + ctx->len;
	174	*p = 0x80;
	175	p++;
	176
	177	rlen = bs - ctx->len -1;
	178	if (rlen)
	179	memset(p, 0, rlen);
	180
	181	if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	182	return err;
	183
6b701dde HX	184	crypto_cipher_encrypt_one(tfm, key3,
6b701dde HX	185	(u8 )(ctx->consts + bs 2));
333b0d7e KM	186
	187	ctx->xor(ctx->prev, ctx->odds, bs);
	188	ctx->xor(ctx->prev, key3, bs);
	189
	190	_crypto_xcbc_digest_setkey(parent, ctx);
	191
6b701dde	192	crypto_cipher_encrypt_one(tfm, out, ctx->prev);
333b0d7e KM	193	}
	194
	195	return 0;
	196	}
	197
333b0d7e KM	198	static int xcbc_init_tfm(struct crypto_tfm *tfm)
333b0d7e KM	199	{
2e306ee0	200	struct crypto_cipher *cipher;
333b0d7e KM	201	struct crypto_instance inst = (void )tfm->__crt_alg;
333b0d7e KM	202	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
3106caab HX	203	struct crypto_xcbc_ctx *ctx = crypto_tfm_ctx(tfm);
3106caab HX	204	int bs = crypto_tfm_alg_blocksize(tfm);
333b0d7e	205
2e306ee0 HX	206	cipher = crypto_spawn_cipher(spawn);
	207	if (IS_ERR(cipher))
	208	return PTR_ERR(cipher);
333b0d7e KM	209
	210	switch(bs) {
	211	case 16:
	212	ctx->xor = xor_128;
	213	break;
	214	default:
	215	return -EINVAL;
	216	}
	217
2e306ee0	218	ctx->child = cipher;
333b0d7e KM	219	ctx->odds = (u8*)(ctx+1);
	220	ctx->prev = ctx->odds + bs;
	221	ctx->key = ctx->prev + bs;
	222
	223	return 0;
	224	};
	225
	226	static void xcbc_exit_tfm(struct crypto_tfm *tfm)
	227	{
3106caab	228	struct crypto_xcbc_ctx *ctx = crypto_tfm_ctx(tfm);
333b0d7e KM	229	crypto_free_cipher(ctx->child);
	230	}
	231
3106caab	232	static int xcbc_create(struct crypto_template tmpl, struct rtattr *tb)
333b0d7e	233	{
3106caab	234	struct shash_instance *inst;
333b0d7e	235	struct crypto_alg *alg;
ebc610e5 HX	236	int err;
ebc610e5 HX	237
3106caab	238	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
ebc610e5	239	if (err)
3106caab	240	return err;
ebc610e5 HX	241
	242	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
	243	CRYPTO_ALG_TYPE_MASK);
333b0d7e	244	if (IS_ERR(alg))
3106caab	245	return PTR_ERR(alg);
333b0d7e KM	246
	247	switch(alg->cra_blocksize) {
	248	case 16:
	249	break;
	250	default:
1b87887d	251	goto out_put_alg;
333b0d7e KM	252	}
333b0d7e KM	253
3106caab	254	inst = shash_alloc_instance("xcbc", alg);
333b0d7e KM	255	if (IS_ERR(inst))
	256	goto out_put_alg;
	257
3106caab HX	258	err = crypto_init_spawn(shash_instance_ctx(inst), alg,
	259	shash_crypto_instance(inst),
	260	CRYPTO_ALG_TYPE_MASK);
	261	if (err)
	262	goto out_free_inst;
	263
	264	inst->alg.base.cra_priority = alg->cra_priority;
	265	inst->alg.base.cra_blocksize = alg->cra_blocksize;
	266	inst->alg.base.cra_alignmask = alg->cra_alignmask;
	267
	268	inst->alg.digestsize = alg->cra_blocksize;
	269	inst->alg.base.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
	270	ALIGN(alg->cra_blocksize * 3,
	271	sizeof(void *));
	272	inst->alg.base.cra_init = xcbc_init_tfm;
	273	inst->alg.base.cra_exit = xcbc_exit_tfm;
	274
	275	inst->alg.init = crypto_xcbc_digest_init;
	276	inst->alg.update = crypto_xcbc_digest_update;
	277	inst->alg.final = crypto_xcbc_digest_final;
	278	inst->alg.setkey = crypto_xcbc_digest_setkey;
	279
	280	err = shash_register_instance(tmpl, inst);
	281	if (err) {
	282	out_free_inst:
	283	shash_free_instance(shash_crypto_instance(inst));
	284	}
333b0d7e KM	285
	286	out_put_alg:
	287	crypto_mod_put(alg);
3106caab	288	return err;
333b0d7e KM	289	}
	290
	291	static struct crypto_template crypto_xcbc_tmpl = {
	292	.name = "xcbc",
3106caab HX	293	.create = xcbc_create,
3106caab HX	294	.free = shash_free_instance,
333b0d7e KM	295	.module = THIS_MODULE,
	296	};
	297
	298	static int __init crypto_xcbc_module_init(void)
	299	{
	300	return crypto_register_template(&crypto_xcbc_tmpl);
	301	}
	302
	303	static void __exit crypto_xcbc_module_exit(void)
	304	{
	305	crypto_unregister_template(&crypto_xcbc_tmpl);
	306	}
	307
	308	module_init(crypto_xcbc_module_init);
	309	module_exit(crypto_xcbc_module_exit);
	310
	311	MODULE_LICENSE("GPL");
	312	MODULE_DESCRIPTION("XCBC keyed hash algorithm");