[linux.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 <[email protected]>
 */

#include <crypto/scatterwalk.h>
#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/hardirq.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/scatterlist.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_hash *parent,
				      struct crypto_xcbc_ctx *ctx)
{
	int bs = crypto_hash_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_hash *parent,
				     const u8 *inkey, unsigned int keylen)
{
	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(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 hash_desc *pdesc)
{
	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(pdesc->tfm);
	int bs = crypto_hash_blocksize(pdesc->tfm);

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

	return 0;
}

static int crypto_xcbc_digest_update2(struct hash_desc *pdesc,
				      struct scatterlist *sg,
				      unsigned int nbytes)
{
	struct crypto_hash *parent = pdesc->tfm;
	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
	struct crypto_cipher *tfm = ctx->child;
	int bs = crypto_hash_blocksize(parent);

	for (;;) {
		struct page *pg = sg_page(sg);
		unsigned int offset = sg->offset;
		unsigned int slen = sg->length;

		if (unlikely(slen > nbytes))
			slen = nbytes;

		nbytes -= slen;

		while (slen > 0) {
			unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
			char *p = crypto_kmap(pg, 0) + offset;

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

				/* checking the rest of the page */
				if (len + offset >= PAGE_SIZE) {
					offset = 0;
					pg++;
				} else
					offset += len;

				crypto_kunmap(p, 0);
				crypto_yield(pdesc->flags);
				continue;
			}

			/* 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;
			}
			crypto_kunmap(p, 0);
			crypto_yield(pdesc->flags);
			slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
			offset = 0;
			pg++;
		}

		if (!nbytes)
			break;
		sg = scatterwalk_sg_next(sg);
	}

	return 0;
}

static int crypto_xcbc_digest_update(struct hash_desc *pdesc,
				     struct scatterlist *sg,
				     unsigned int nbytes)
{
	if (WARN_ON_ONCE(in_irq()))
		return -EDEADLK;
	return crypto_xcbc_digest_update2(pdesc, sg, nbytes);
}

static int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out)
{
	struct crypto_hash *parent = pdesc->tfm;
	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
	struct crypto_cipher *tfm = ctx->child;
	int bs = crypto_hash_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 crypto_xcbc_digest(struct hash_desc *pdesc,
		  struct scatterlist *sg, unsigned int nbytes, u8 *out)
{
	if (WARN_ON_ONCE(in_irq()))
		return -EDEADLK;

	crypto_xcbc_digest_init(pdesc);
	crypto_xcbc_digest_update2(pdesc, sg, nbytes);
	return crypto_xcbc_digest_final(pdesc, out);
}

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_hash_ctx_aligned(__crypto_hash_cast(tfm));
	int bs = crypto_hash_blocksize(__crypto_hash_cast(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_hash_ctx_aligned(__crypto_hash_cast(tfm));
	crypto_free_cipher(ctx->child);
}

static struct crypto_instance *xcbc_alloc(struct rtattr **tb)
{
	struct crypto_instance *inst;
	struct crypto_alg *alg;
	int err;

	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH);
	if (err)
		return ERR_PTR(err);

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

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

	inst = crypto_alloc_instance("xcbc", alg);
	if (IS_ERR(inst))
		goto out_put_alg;

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
	inst->alg.cra_priority = alg->cra_priority;
	inst->alg.cra_blocksize = alg->cra_blocksize;
	inst->alg.cra_alignmask = alg->cra_alignmask;
	inst->alg.cra_type = &crypto_hash_type;

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

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

out_put_alg:
	crypto_mod_put(alg);
	return inst;
}

static void xcbc_free(struct crypto_instance *inst)
{
	crypto_drop_spawn(crypto_instance_ctx(inst));
	kfree(inst);
}

static struct crypto_template crypto_xcbc_tmpl = {
	.name = "xcbc",
	.alloc = xcbc_alloc,
	.free = xcbc_free,
	.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 <[email protected]>
	20	*/
	21
42c271c6	22	#include <crypto/scatterwalk.h>
333b0d7e KM	23	#include <linux/crypto.h>
333b0d7e KM	24	#include <linux/err.h>
fb469840	25	#include <linux/hardirq.h>
333b0d7e KM	26	#include <linux/kernel.h>
	27	#include <linux/mm.h>
	28	#include <linux/rtnetlink.h>
	29	#include <linux/slab.h>
	30	#include <linux/scatterlist.h>
333b0d7e	31
5b37538a AB	32	static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
	33	0x02020202, 0x02020202, 0x02020202, 0x02020202,
	34	0x03030303, 0x03030303, 0x03030303, 0x03030303};
333b0d7e KM	35	/*
	36	* +------------------------
	37	* \| <parent tfm>
	38	* +------------------------
	39	* \| crypto_xcbc_ctx
	40	* +------------------------
	41	* \| odds (block size)
	42	* +------------------------
	43	* \| prev (block size)
	44	* +------------------------
	45	* \| key (block size)
	46	* +------------------------
	47	* \| consts (block size * 3)
	48	* +------------------------
	49	*/
	50	struct crypto_xcbc_ctx {
6b701dde	51	struct crypto_cipher *child;
333b0d7e KM	52	u8 *odds;
	53	u8 *prev;
	54	u8 *key;
	55	u8 *consts;
	56	void (xor)(u8 a, const u8 *b, unsigned int bs);
	57	unsigned int keylen;
	58	unsigned int len;
	59	};
	60
	61	static void xor_128(u8 a, const u8 b, unsigned int bs)
	62	{
	63	((u32 )a)[0] ^= ((u32 )b)[0];
	64	((u32 )a)[1] ^= ((u32 )b)[1];
	65	((u32 )a)[2] ^= ((u32 )b)[2];
	66	((u32 )a)[3] ^= ((u32 )b)[3];
	67	}
	68
	69	static int _crypto_xcbc_digest_setkey(struct crypto_hash *parent,
	70	struct crypto_xcbc_ctx *ctx)
	71	{
	72	int bs = crypto_hash_blocksize(parent);
	73	int err = 0;
	74	u8 key1[bs];
	75
	76	if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
	77	return err;
	78
6b701dde	79	crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts);
333b0d7e KM	80
	81	return crypto_cipher_setkey(ctx->child, key1, bs);
	82	}
	83
	84	static int crypto_xcbc_digest_setkey(struct crypto_hash *parent,
	85	const u8 *inkey, unsigned int keylen)
	86	{
	87	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
	88
6b701dde	89	if (keylen != crypto_cipher_blocksize(ctx->child))
333b0d7e KM	90	return -EINVAL;
	91
	92	ctx->keylen = keylen;
	93	memcpy(ctx->key, inkey, keylen);
	94	ctx->consts = (u8*)ks;
	95
	96	return _crypto_xcbc_digest_setkey(parent, ctx);
	97	}
	98
5b37538a	99	static int crypto_xcbc_digest_init(struct hash_desc *pdesc)
333b0d7e KM	100	{
	101	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(pdesc->tfm);
	102	int bs = crypto_hash_blocksize(pdesc->tfm);
	103
	104	ctx->len = 0;
	105	memset(ctx->odds, 0, bs);
	106	memset(ctx->prev, 0, bs);
	107
	108	return 0;
	109	}
	110
fb469840 HX	111	static int crypto_xcbc_digest_update2(struct hash_desc *pdesc,
	112	struct scatterlist *sg,
	113	unsigned int nbytes)
333b0d7e KM	114	{
	115	struct crypto_hash *parent = pdesc->tfm;
	116	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
6b701dde	117	struct crypto_cipher *tfm = ctx->child;
333b0d7e	118	int bs = crypto_hash_blocksize(parent);
333b0d7e	119
1edcf2e1 JL	120	for (;;) {
	121	struct page *pg = sg_page(sg);
	122	unsigned int offset = sg->offset;
	123	unsigned int slen = sg->length;
333b0d7e	124
2f40a178 JL	125	if (unlikely(slen > nbytes))
	126	slen = nbytes;
	127
	128	nbytes -= slen;
	129
333b0d7e KM	130	while (slen > 0) {
	131	unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
	132	char *p = crypto_kmap(pg, 0) + offset;
	133
	134	/* checking the data can fill the block */
	135	if ((ctx->len + len) <= bs) {
	136	memcpy(ctx->odds + ctx->len, p, len);
	137	ctx->len += len;
	138	slen -= len;
	139
	140	/* checking the rest of the page */
	141	if (len + offset >= PAGE_SIZE) {
	142	offset = 0;
	143	pg++;
	144	} else
	145	offset += len;
	146
	147	crypto_kunmap(p, 0);
6b701dde	148	crypto_yield(pdesc->flags);
333b0d7e KM	149	continue;
	150	}
	151
	152	/* filling odds with new data and encrypting it */
	153	memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
	154	len -= bs - ctx->len;
	155	p += bs - ctx->len;
	156
	157	ctx->xor(ctx->prev, ctx->odds, bs);
6b701dde	158	crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
333b0d7e KM	159
	160	/* clearing the length */
	161	ctx->len = 0;
	162
	163	/* encrypting the rest of data */
	164	while (len > bs) {
	165	ctx->xor(ctx->prev, p, bs);
6b701dde HX	166	crypto_cipher_encrypt_one(tfm, ctx->prev,
6b701dde HX	167	ctx->prev);
333b0d7e KM	168	p += bs;
	169	len -= bs;
	170	}
	171
	172	/* keeping the surplus of blocksize */
	173	if (len) {
	174	memcpy(ctx->odds, p, len);
	175	ctx->len = len;
	176	}
	177	crypto_kunmap(p, 0);
6b701dde	178	crypto_yield(pdesc->flags);
333b0d7e KM	179	slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
	180	offset = 0;
	181	pg++;
	182	}
1edcf2e1 JL	183
	184	if (!nbytes)
	185	break;
	186	sg = scatterwalk_sg_next(sg);
	187	}
333b0d7e KM	188
	189	return 0;
	190	}
	191
fb469840 HX	192	static int crypto_xcbc_digest_update(struct hash_desc *pdesc,
	193	struct scatterlist *sg,
	194	unsigned int nbytes)
	195	{
	196	if (WARN_ON_ONCE(in_irq()))
	197	return -EDEADLK;
	198	return crypto_xcbc_digest_update2(pdesc, sg, nbytes);
	199	}
	200
5b37538a	201	static int crypto_xcbc_digest_final(struct hash_desc pdesc, u8 out)
333b0d7e KM	202	{
	203	struct crypto_hash *parent = pdesc->tfm;
	204	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
6b701dde	205	struct crypto_cipher *tfm = ctx->child;
333b0d7e KM	206	int bs = crypto_hash_blocksize(parent);
	207	int err = 0;
	208
	209	if (ctx->len == bs) {
	210	u8 key2[bs];
	211
	212	if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	213	return err;
	214
6b701dde HX	215	crypto_cipher_encrypt_one(tfm, key2,
6b701dde HX	216	(u8 *)(ctx->consts + bs));
333b0d7e KM	217
	218	ctx->xor(ctx->prev, ctx->odds, bs);
	219	ctx->xor(ctx->prev, key2, bs);
	220	_crypto_xcbc_digest_setkey(parent, ctx);
	221
6b701dde	222	crypto_cipher_encrypt_one(tfm, out, ctx->prev);
333b0d7e KM	223	} else {
	224	u8 key3[bs];
	225	unsigned int rlen;
	226	u8 *p = ctx->odds + ctx->len;
	227	*p = 0x80;
	228	p++;
	229
	230	rlen = bs - ctx->len -1;
	231	if (rlen)
	232	memset(p, 0, rlen);
	233
	234	if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	235	return err;
	236
6b701dde HX	237	crypto_cipher_encrypt_one(tfm, key3,
6b701dde HX	238	(u8 )(ctx->consts + bs 2));
333b0d7e KM	239
	240	ctx->xor(ctx->prev, ctx->odds, bs);
	241	ctx->xor(ctx->prev, key3, bs);
	242
	243	_crypto_xcbc_digest_setkey(parent, ctx);
	244
6b701dde	245	crypto_cipher_encrypt_one(tfm, out, ctx->prev);
333b0d7e KM	246	}
	247
	248	return 0;
	249	}
	250
	251	static int crypto_xcbc_digest(struct hash_desc *pdesc,
	252	struct scatterlist sg, unsigned int nbytes, u8 out)
	253	{
fb469840 HX	254	if (WARN_ON_ONCE(in_irq()))
	255	return -EDEADLK;
	256
333b0d7e	257	crypto_xcbc_digest_init(pdesc);
fb469840	258	crypto_xcbc_digest_update2(pdesc, sg, nbytes);
333b0d7e KM	259	return crypto_xcbc_digest_final(pdesc, out);
	260	}
	261
	262	static int xcbc_init_tfm(struct crypto_tfm *tfm)
	263	{
2e306ee0	264	struct crypto_cipher *cipher;
333b0d7e KM	265	struct crypto_instance inst = (void )tfm->__crt_alg;
	266	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	267	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
	268	int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm));
	269
2e306ee0 HX	270	cipher = crypto_spawn_cipher(spawn);
	271	if (IS_ERR(cipher))
	272	return PTR_ERR(cipher);
333b0d7e KM	273
	274	switch(bs) {
	275	case 16:
	276	ctx->xor = xor_128;
	277	break;
	278	default:
	279	return -EINVAL;
	280	}
	281
2e306ee0	282	ctx->child = cipher;
333b0d7e KM	283	ctx->odds = (u8*)(ctx+1);
	284	ctx->prev = ctx->odds + bs;
	285	ctx->key = ctx->prev + bs;
	286
	287	return 0;
	288	};
	289
	290	static void xcbc_exit_tfm(struct crypto_tfm *tfm)
	291	{
	292	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
	293	crypto_free_cipher(ctx->child);
	294	}
	295
ebc610e5	296	static struct crypto_instance xcbc_alloc(struct rtattr *tb)
333b0d7e KM	297	{
	298	struct crypto_instance *inst;
	299	struct crypto_alg *alg;
ebc610e5 HX	300	int err;
	301
	302	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH);
	303	if (err)
	304	return ERR_PTR(err);
	305
	306	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
	307	CRYPTO_ALG_TYPE_MASK);
333b0d7e	308	if (IS_ERR(alg))
e231c2ee	309	return ERR_CAST(alg);
333b0d7e KM	310
	311	switch(alg->cra_blocksize) {
	312	case 16:
	313	break;
	314	default:
1b87887d HX	315	inst = ERR_PTR(-EINVAL);
1b87887d HX	316	goto out_put_alg;
333b0d7e KM	317	}
	318
	319	inst = crypto_alloc_instance("xcbc", alg);
	320	if (IS_ERR(inst))
	321	goto out_put_alg;
	322
	323	inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
	324	inst->alg.cra_priority = alg->cra_priority;
	325	inst->alg.cra_blocksize = alg->cra_blocksize;
	326	inst->alg.cra_alignmask = alg->cra_alignmask;
	327	inst->alg.cra_type = &crypto_hash_type;
	328
94765b9e	329	inst->alg.cra_hash.digestsize = alg->cra_blocksize;
333b0d7e KM	330	inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
	331	ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *));
	332	inst->alg.cra_init = xcbc_init_tfm;
	333	inst->alg.cra_exit = xcbc_exit_tfm;
	334
	335	inst->alg.cra_hash.init = crypto_xcbc_digest_init;
	336	inst->alg.cra_hash.update = crypto_xcbc_digest_update;
	337	inst->alg.cra_hash.final = crypto_xcbc_digest_final;
	338	inst->alg.cra_hash.digest = crypto_xcbc_digest;
	339	inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey;
	340
	341	out_put_alg:
	342	crypto_mod_put(alg);
	343	return inst;
	344	}
	345
	346	static void xcbc_free(struct crypto_instance *inst)
	347	{
	348	crypto_drop_spawn(crypto_instance_ctx(inst));
	349	kfree(inst);
	350	}
	351
	352	static struct crypto_template crypto_xcbc_tmpl = {
	353	.name = "xcbc",
	354	.alloc = xcbc_alloc,
	355	.free = xcbc_free,
	356	.module = THIS_MODULE,
	357	};
	358
	359	static int __init crypto_xcbc_module_init(void)
	360	{
	361	return crypto_register_template(&crypto_xcbc_tmpl);
	362	}
	363
	364	static void __exit crypto_xcbc_module_exit(void)
	365	{
	366	crypto_unregister_template(&crypto_xcbc_tmpl);
	367	}
	368
	369	module_init(crypto_xcbc_module_init);
	370	module_exit(crypto_xcbc_module_exit);
	371
	372	MODULE_LICENSE("GPL");
	373	MODULE_DESCRIPTION("XCBC keyed hash algorithm");