[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 <linux/crypto.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/scatterlist.h>
#include "internal.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_tfm *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;

	ctx->child->__crt_alg->cra_cipher.cia_encrypt(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_tfm_alg_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_update(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_tfm *tfm = ctx->child;
	int bs = crypto_hash_blocksize(parent);
	unsigned int i = 0;

	do {

		struct page *pg = sg[i].page;
		unsigned int offset = sg[i].offset;
		unsigned int slen = sg[i].length;

		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(tfm->crt_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);
			tfm->__crt_alg->cra_cipher.cia_encrypt(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);
				tfm->__crt_alg->cra_cipher.cia_encrypt(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(tfm->crt_flags);
			slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
			offset = 0;
			pg++;
		}
		nbytes-=sg[i].length;
		i++;
	} while (nbytes>0);

	return 0;
}

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_tfm *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;

		tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key2, (const u8*)(ctx->consts+bs));

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

		tfm->__crt_alg->cra_cipher.cia_encrypt(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;

		tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key3, (const u8*)(ctx->consts+bs*2));

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

		_crypto_xcbc_digest_setkey(parent, ctx);

		tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev);
	}

	return 0;
}

static int crypto_xcbc_digest(struct hash_desc *pdesc,
		  struct scatterlist *sg, unsigned int nbytes, u8 *out)
{
	crypto_xcbc_digest_init(pdesc);
	crypto_xcbc_digest_update(pdesc, sg, nbytes);
	return crypto_xcbc_digest_final(pdesc, out);
}

static int xcbc_init_tfm(struct crypto_tfm *tfm)
{
	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));

	tfm = crypto_spawn_tfm(spawn);
	if (IS_ERR(tfm))
		return PTR_ERR(tfm);

	switch(bs) {
	case 16:
		ctx->xor = xor_128;
		break;
	default:
		return -EINVAL;
	}

	ctx->child = crypto_cipher_cast(tfm);
	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(void *param, unsigned int len)
{
	struct crypto_instance *inst;
	struct crypto_alg *alg;
	alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER,
				  CRYPTO_ALG_TYPE_HASH_MASK | CRYPTO_ALG_ASYNC);
	if (IS_ERR(alg))
		return ERR_PTR(PTR_ERR(alg));

	switch(alg->cra_blocksize) {
	case 16:
		break;
	default:
		return ERR_PTR(PTR_ERR(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_flags & CRYPTO_ALG_TYPE_MASK) ==
		CRYPTO_ALG_TYPE_HASH ? 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
	22	#include <linux/crypto.h>
	23	#include <linux/err.h>
	24	#include <linux/kernel.h>
	25	#include <linux/mm.h>
	26	#include <linux/rtnetlink.h>
	27	#include <linux/slab.h>
	28	#include <linux/scatterlist.h>
	29	#include "internal.h"
	30
5b37538a AB	31	static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
	32	0x02020202, 0x02020202, 0x02020202, 0x02020202,
	33	0x03030303, 0x03030303, 0x03030303, 0x03030303};
333b0d7e KM	34	/*
	35	* +------------------------
	36	* \| <parent tfm>
	37	* +------------------------
	38	* \| crypto_xcbc_ctx
	39	* +------------------------
	40	* \| odds (block size)
	41	* +------------------------
	42	* \| prev (block size)
	43	* +------------------------
	44	* \| key (block size)
	45	* +------------------------
	46	* \| consts (block size * 3)
	47	* +------------------------
	48	*/
	49	struct crypto_xcbc_ctx {
	50	struct crypto_tfm *child;
	51	u8 *odds;
	52	u8 *prev;
	53	u8 *key;
	54	u8 *consts;
	55	void (xor)(u8 a, const u8 *b, unsigned int bs);
	56	unsigned int keylen;
	57	unsigned int len;
	58	};
	59
	60	static void xor_128(u8 a, const u8 b, unsigned int bs)
	61	{
	62	((u32 )a)[0] ^= ((u32 )b)[0];
	63	((u32 )a)[1] ^= ((u32 )b)[1];
	64	((u32 )a)[2] ^= ((u32 )b)[2];
	65	((u32 )a)[3] ^= ((u32 )b)[3];
	66	}
	67
	68	static int _crypto_xcbc_digest_setkey(struct crypto_hash *parent,
	69	struct crypto_xcbc_ctx *ctx)
	70	{
	71	int bs = crypto_hash_blocksize(parent);
	72	int err = 0;
	73	u8 key1[bs];
	74
	75	if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
	76	return err;
	77
	78	ctx->child->__crt_alg->cra_cipher.cia_encrypt(ctx->child, key1,
	79	ctx->consts);
	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
	89	if (keylen != crypto_tfm_alg_blocksize(ctx->child))
	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
5b37538a AB	111	static int crypto_xcbc_digest_update(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);
	117	struct crypto_tfm *tfm = ctx->child;
	118	int bs = crypto_hash_blocksize(parent);
	119	unsigned int i = 0;
	120
	121	do {
	122
	123	struct page *pg = sg[i].page;
	124	unsigned int offset = sg[i].offset;
	125	unsigned int slen = sg[i].length;
	126
	127	while (slen > 0) {
	128	unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
	129	char *p = crypto_kmap(pg, 0) + offset;
	130
	131	/* checking the data can fill the block */
	132	if ((ctx->len + len) <= bs) {
	133	memcpy(ctx->odds + ctx->len, p, len);
	134	ctx->len += len;
	135	slen -= len;
	136
	137	/* checking the rest of the page */
	138	if (len + offset >= PAGE_SIZE) {
	139	offset = 0;
	140	pg++;
	141	} else
	142	offset += len;
	143
	144	crypto_kunmap(p, 0);
	145	crypto_yield(tfm->crt_flags);
	146	continue;
	147	}
	148
	149	/* filling odds with new data and encrypting it */
	150	memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
	151	len -= bs - ctx->len;
	152	p += bs - ctx->len;
	153
	154	ctx->xor(ctx->prev, ctx->odds, bs);
	155	tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, ctx->prev, ctx->prev);
	156
	157	/* clearing the length */
	158	ctx->len = 0;
	159
	160	/* encrypting the rest of data */
	161	while (len > bs) {
	162	ctx->xor(ctx->prev, p, bs);
	163	tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, ctx->prev, ctx->prev);
	164	p += bs;
	165	len -= bs;
	166	}
	167
	168	/* keeping the surplus of blocksize */
	169	if (len) {
	170	memcpy(ctx->odds, p, len);
	171	ctx->len = len;
	172	}
	173	crypto_kunmap(p, 0);
	174	crypto_yield(tfm->crt_flags);
	175	slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
	176	offset = 0;
	177	pg++;
178	}
179	nbytes-=sg[i].length;
180	i++;
181	} while (nbytes>0);
182
183	return 0;
184	}
185
5b37538a	186	static int crypto_xcbc_digest_final(struct hash_desc pdesc, u8 out)
333b0d7e KM	187	{
	188	struct crypto_hash *parent = pdesc->tfm;
	189	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
	190	struct crypto_tfm *tfm = ctx->child;
	191	int bs = crypto_hash_blocksize(parent);
	192	int err = 0;
	193
	194	if (ctx->len == bs) {
	195	u8 key2[bs];
	196
	197	if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	198	return err;
	199
	200	tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key2, (const u8*)(ctx->consts+bs));
	201
	202	ctx->xor(ctx->prev, ctx->odds, bs);
	203	ctx->xor(ctx->prev, key2, bs);
	204	_crypto_xcbc_digest_setkey(parent, ctx);
	205
	206	tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev);
	207	} else {
	208	u8 key3[bs];
	209	unsigned int rlen;
	210	u8 *p = ctx->odds + ctx->len;
	211	*p = 0x80;
	212	p++;
	213
	214	rlen = bs - ctx->len -1;
	215	if (rlen)
	216	memset(p, 0, rlen);
	217
	218	if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	219	return err;
	220
	221	tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key3, (const u8)(ctx->consts+bs2));
	222
	223	ctx->xor(ctx->prev, ctx->odds, bs);
	224	ctx->xor(ctx->prev, key3, bs);
	225
	226	_crypto_xcbc_digest_setkey(parent, ctx);
	227
	228	tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev);
	229	}
	230
	231	return 0;
	232	}
	233
	234	static int crypto_xcbc_digest(struct hash_desc *pdesc,
	235	struct scatterlist sg, unsigned int nbytes, u8 out)
	236	{
	237	crypto_xcbc_digest_init(pdesc);
	238	crypto_xcbc_digest_update(pdesc, sg, nbytes);
	239	return crypto_xcbc_digest_final(pdesc, out);
	240	}
	241
	242	static int xcbc_init_tfm(struct crypto_tfm *tfm)
	243	{
	244	struct crypto_instance inst = (void )tfm->__crt_alg;
	245	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	246	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
	247	int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm));
	248
	249	tfm = crypto_spawn_tfm(spawn);
	250	if (IS_ERR(tfm))
251	return PTR_ERR(tfm);
252
253	switch(bs) {
254	case 16:
255	ctx->xor = xor_128;
256	break;
257	default:
258	return -EINVAL;
259	}
260
261	ctx->child = crypto_cipher_cast(tfm);
262	ctx->odds = (u8*)(ctx+1);
263	ctx->prev = ctx->odds + bs;
264	ctx->key = ctx->prev + bs;
265
266	return 0;
267	};
268
269	static void xcbc_exit_tfm(struct crypto_tfm *tfm)
270	{
271	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
272	crypto_free_cipher(ctx->child);
273	}
274
275	static struct crypto_instance xcbc_alloc(void param, unsigned int len)
276	{
277	struct crypto_instance *inst;
278	struct crypto_alg *alg;
279	alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER,
280	CRYPTO_ALG_TYPE_HASH_MASK \| CRYPTO_ALG_ASYNC);
281	if (IS_ERR(alg))
282	return ERR_PTR(PTR_ERR(alg));
283
284	switch(alg->cra_blocksize) {
285	case 16:
286	break;
287	default:
288	return ERR_PTR(PTR_ERR(alg));
289	}
290
291	inst = crypto_alloc_instance("xcbc", alg);
292	if (IS_ERR(inst))
293	goto out_put_alg;
294
295	inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
296	inst->alg.cra_priority = alg->cra_priority;
297	inst->alg.cra_blocksize = alg->cra_blocksize;
298	inst->alg.cra_alignmask = alg->cra_alignmask;
299	inst->alg.cra_type = &crypto_hash_type;
300
301	inst->alg.cra_hash.digestsize =
302	(alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
303	CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize :
304	alg->cra_blocksize;
305	inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
306	ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *));
307	inst->alg.cra_init = xcbc_init_tfm;
308	inst->alg.cra_exit = xcbc_exit_tfm;
309
310	inst->alg.cra_hash.init = crypto_xcbc_digest_init;
311	inst->alg.cra_hash.update = crypto_xcbc_digest_update;
312	inst->alg.cra_hash.final = crypto_xcbc_digest_final;
313	inst->alg.cra_hash.digest = crypto_xcbc_digest;
314	inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey;
315
316	out_put_alg:
317	crypto_mod_put(alg);
318	return inst;
319	}
320
321	static void xcbc_free(struct crypto_instance *inst)
322	{
323	crypto_drop_spawn(crypto_instance_ctx(inst));
324	kfree(inst);
325	}
326
327	static struct crypto_template crypto_xcbc_tmpl = {
328	.name = "xcbc",
329	.alloc = xcbc_alloc,
330	.free = xcbc_free,
331	.module = THIS_MODULE,
332	};
333
334	static int __init crypto_xcbc_module_init(void)
335	{
336	return crypto_register_template(&crypto_xcbc_tmpl);
337	}
338
339	static void __exit crypto_xcbc_module_exit(void)
340	{
341	crypto_unregister_template(&crypto_xcbc_tmpl);
342	}
343
344	module_init(crypto_xcbc_module_init);
345	module_exit(crypto_xcbc_module_exit);
346
347	MODULE_LICENSE("GPL");
348	MODULE_DESCRIPTION("XCBC keyed hash algorithm");