[mirror_ubuntu-artful-kernel.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>
#include <linux/module.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");
MODULE_ALIAS_CRYPTO("xcbc");
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>
4bb33cc8	25	#include <linux/module.h>
333b0d7e	26
5b37538a AB	27	static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
	28	0x02020202, 0x02020202, 0x02020202, 0x02020202,
	29	0x03030303, 0x03030303, 0x03030303, 0x03030303};
ac95301f	30
333b0d7e KM	31	/*
	32	* +------------------------
	33	* \| <parent tfm>
	34	* +------------------------
ac95301f	35	* \| xcbc_tfm_ctx
333b0d7e	36	* +------------------------
ac95301f	37	* \| consts (block size * 2)
333b0d7e	38	* +------------------------
ac95301f HX	39	*/
	40	struct xcbc_tfm_ctx {
	41	struct crypto_cipher *child;
	42	u8 ctx[];
	43	};
	44
	45	/*
333b0d7e	46	* +------------------------
ac95301f	47	* \| <shash desc>
333b0d7e	48	* +------------------------
ac95301f HX	49	* \| xcbc_desc_ctx
	50	* +------------------------
	51	* \| odds (block size)
	52	* +------------------------
	53	* \| prev (block size)
333b0d7e KM	54	* +------------------------
333b0d7e KM	55	*/
ac95301f	56	struct xcbc_desc_ctx {
333b0d7e	57	unsigned int len;
ac95301f	58	u8 ctx[];
333b0d7e KM	59	};
333b0d7e KM	60
ac95301f HX	61	static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
ac95301f HX	62	const u8 *inkey, unsigned int keylen)
333b0d7e	63	{
ac95301f HX	64	unsigned long alignmask = crypto_shash_alignmask(parent);
ac95301f HX	65	struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent);
3106caab	66	int bs = crypto_shash_blocksize(parent);
ac95301f	67	u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
333b0d7e KM	68	int err = 0;
	69	u8 key1[bs];
	70
ac95301f HX	71	if ((err = crypto_cipher_setkey(ctx->child, inkey, keylen)))
ac95301f HX	72	return err;
333b0d7e	73
ac95301f HX	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);
333b0d7e KM	77
333b0d7e KM	78	return crypto_cipher_setkey(ctx->child, key1, bs);
333b0d7e	79
333b0d7e KM	80	}
333b0d7e KM	81
3106caab	82	static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
333b0d7e	83	{
ac95301f HX	84	unsigned long alignmask = crypto_shash_alignmask(pdesc->tfm);
ac95301f HX	85	struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
3106caab	86	int bs = crypto_shash_blocksize(pdesc->tfm);
ac95301f	87	u8 *prev = PTR_ALIGN(&ctx->ctx[0], alignmask + 1) + bs;
333b0d7e KM	88
333b0d7e KM	89	ctx->len = 0;
ac95301f	90	memset(prev, 0, bs);
333b0d7e KM	91
	92	return 0;
	93	}
	94
3106caab HX	95	static int crypto_xcbc_digest_update(struct shash_desc pdesc, const u8 p,
3106caab HX	96	unsigned int len)
333b0d7e	97	{
3106caab	98	struct crypto_shash *parent = pdesc->tfm;
ac95301f HX	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;
3106caab	103	int bs = crypto_shash_blocksize(parent);
ac95301f HX	104	u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
ac95301f HX	105	u8 *prev = odds + bs;
3106caab HX	106
	107	/* checking the data can fill the block */
	108	if ((ctx->len + len) <= bs) {
ac95301f	109	memcpy(odds + ctx->len, p, len);
3106caab HX	110	ctx->len += len;
3106caab HX	111	return 0;
1edcf2e1	112	}
333b0d7e	113
3106caab	114	/* filling odds with new data and encrypting it */
ac95301f	115	memcpy(odds + ctx->len, p, bs - ctx->len);
3106caab HX	116	len -= bs - ctx->len;
3106caab HX	117	p += bs - ctx->len;
333b0d7e	118
ac95301f HX	119	crypto_xor(prev, odds, bs);
ac95301f HX	120	crypto_cipher_encrypt_one(tfm, prev, prev);
3106caab HX	121
	122	/* clearing the length */
	123	ctx->len = 0;
	124
	125	/* encrypting the rest of data */
	126	while (len > bs) {
ac95301f HX	127	crypto_xor(prev, p, bs);
ac95301f HX	128	crypto_cipher_encrypt_one(tfm, prev, prev);
3106caab HX	129	p += bs;
	130	len -= bs;
	131	}
	132
	133	/* keeping the surplus of blocksize */
	134	if (len) {
ac95301f	135	memcpy(odds, p, len);
3106caab HX	136	ctx->len = len;
	137	}
	138
	139	return 0;
fb469840 HX	140	}
fb469840 HX	141
3106caab	142	static int crypto_xcbc_digest_final(struct shash_desc pdesc, u8 out)
333b0d7e	143	{
3106caab	144	struct crypto_shash *parent = pdesc->tfm;
ac95301f HX	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;
3106caab	149	int bs = crypto_shash_blocksize(parent);
ac95301f HX	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;
333b0d7e	154
ac95301f	155	if (ctx->len != bs) {
333b0d7e	156	unsigned int rlen;
ac95301f HX	157	u8 *p = odds + ctx->len;
ac95301f HX	158
333b0d7e KM	159	*p = 0x80;
	160	p++;
	161
	162	rlen = bs - ctx->len -1;
	163	if (rlen)
	164	memset(p, 0, rlen);
	165
ac95301f HX	166	offset += bs;
ac95301f HX	167	}
333b0d7e	168
ac95301f HX	169	crypto_xor(prev, odds, bs);
ac95301f HX	170	crypto_xor(prev, consts + offset, bs);
333b0d7e	171
ac95301f	172	crypto_cipher_encrypt_one(tfm, out, prev);
333b0d7e KM	173
	174	return 0;
	175	}
	176
333b0d7e KM	177	static int xcbc_init_tfm(struct crypto_tfm *tfm)
333b0d7e KM	178	{
2e306ee0	179	struct crypto_cipher *cipher;
333b0d7e KM	180	struct crypto_instance inst = (void )tfm->__crt_alg;
333b0d7e KM	181	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
ac95301f	182	struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
333b0d7e	183
2e306ee0 HX	184	cipher = crypto_spawn_cipher(spawn);
	185	if (IS_ERR(cipher))
	186	return PTR_ERR(cipher);
333b0d7e	187
2e306ee0	188	ctx->child = cipher;
333b0d7e KM	189
	190	return 0;
	191	};
	192
	193	static void xcbc_exit_tfm(struct crypto_tfm *tfm)
	194	{
ac95301f	195	struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
333b0d7e KM	196	crypto_free_cipher(ctx->child);
	197	}
	198
3106caab	199	static int xcbc_create(struct crypto_template tmpl, struct rtattr *tb)
333b0d7e	200	{
3106caab	201	struct shash_instance *inst;
333b0d7e	202	struct crypto_alg *alg;
36f87a4a	203	unsigned long alignmask;
ebc610e5 HX	204	int err;
ebc610e5 HX	205
3106caab	206	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
ebc610e5	207	if (err)
3106caab	208	return err;
ebc610e5 HX	209
	210	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
	211	CRYPTO_ALG_TYPE_MASK);
333b0d7e	212	if (IS_ERR(alg))
3106caab	213	return PTR_ERR(alg);
333b0d7e KM	214
	215	switch(alg->cra_blocksize) {
	216	case 16:
	217	break;
	218	default:
1b87887d	219	goto out_put_alg;
333b0d7e KM	220	}
333b0d7e KM	221
3106caab	222	inst = shash_alloc_instance("xcbc", alg);
b5ebd44e	223	err = PTR_ERR(inst);
333b0d7e KM	224	if (IS_ERR(inst))
	225	goto out_put_alg;
	226
3106caab HX	227	err = crypto_init_spawn(shash_instance_ctx(inst), alg,
	228	shash_crypto_instance(inst),
	229	CRYPTO_ALG_TYPE_MASK);
	230	if (err)
	231	goto out_free_inst;
	232
36f87a4a SK	233	alignmask = alg->cra_alignmask \| 3;
36f87a4a SK	234	inst->alg.base.cra_alignmask = alignmask;
3106caab HX	235	inst->alg.base.cra_priority = alg->cra_priority;
3106caab HX	236	inst->alg.base.cra_blocksize = alg->cra_blocksize;
3106caab HX	237
3106caab HX	238	inst->alg.digestsize = alg->cra_blocksize;
ac95301f HX	239	inst->alg.descsize = ALIGN(sizeof(struct xcbc_desc_ctx),
ac95301f HX	240	crypto_tfm_ctx_alignment()) +
36f87a4a	241	(alignmask &
ac95301f HX	242	~(crypto_tfm_ctx_alignment() - 1)) +
	243	alg->cra_blocksize * 2;
	244
	245	inst->alg.base.cra_ctxsize = ALIGN(sizeof(struct xcbc_tfm_ctx),
36f87a4a	246	alignmask + 1) +
ac95301f	247	alg->cra_blocksize * 2;
3106caab HX	248	inst->alg.base.cra_init = xcbc_init_tfm;
	249	inst->alg.base.cra_exit = xcbc_exit_tfm;
	250
	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;
	255
	256	err = shash_register_instance(tmpl, inst);
	257	if (err) {
	258	out_free_inst:
	259	shash_free_instance(shash_crypto_instance(inst));
	260	}
333b0d7e KM	261
	262	out_put_alg:
	263	crypto_mod_put(alg);
3106caab	264	return err;
333b0d7e KM	265	}
	266
	267	static struct crypto_template crypto_xcbc_tmpl = {
	268	.name = "xcbc",
3106caab HX	269	.create = xcbc_create,
3106caab HX	270	.free = shash_free_instance,
333b0d7e KM	271	.module = THIS_MODULE,
	272	};
	273
	274	static int __init crypto_xcbc_module_init(void)
	275	{
	276	return crypto_register_template(&crypto_xcbc_tmpl);
	277	}
	278
	279	static void __exit crypto_xcbc_module_exit(void)
	280	{
	281	crypto_unregister_template(&crypto_xcbc_tmpl);
	282	}
	283
	284	module_init(crypto_xcbc_module_init);
	285	module_exit(crypto_xcbc_module_exit);
	286
	287	MODULE_LICENSE("GPL");
	288	MODULE_DESCRIPTION("XCBC keyed hash algorithm");
4943ba16	289	MODULE_ALIAS_CRYPTO("xcbc");