[linux.git] / crypto / xts.c

/* XTS: as defined in IEEE1619/D16
 *	http://grouper.ieee.org/groups/1619/email/pdf00086.pdf
 *	(sector sizes which are not a multiple of 16 bytes are,
 *	however currently unsupported)
 *
 * Copyright (c) 2007 Rik Snel <[email protected]>
 *
 * Based om ecb.c
 * Copyright (c) 2006 Herbert Xu <[email protected]>
 *
 * 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.
 */
#include <crypto/algapi.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>

#include <crypto/xts.h>
#include <crypto/b128ops.h>
#include <crypto/gf128mul.h>

struct priv {
	struct crypto_cipher *child;
	struct crypto_cipher *tweak;
};

static int setkey(struct crypto_tfm *parent, const u8 *key,
		  unsigned int keylen)
{
	struct priv *ctx = crypto_tfm_ctx(parent);
	struct crypto_cipher *child = ctx->tweak;
	u32 *flags = &parent->crt_flags;
	int err;

	/* key consists of keys of equal size concatenated, therefore
	 * the length must be even */
	if (keylen % 2) {
		/* tell the user why there was an error */
		*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
		return -EINVAL;
	}

	/* we need two cipher instances: one to compute the initial 'tweak'
	 * by encrypting the IV (usually the 'plain' iv) and the other
	 * one to encrypt and decrypt the data */

	/* tweak cipher, uses Key2 i.e. the second half of *key */
	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
				       CRYPTO_TFM_REQ_MASK);
	err = crypto_cipher_setkey(child, key + keylen/2, keylen/2);
	if (err)
		return err;

	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
				     CRYPTO_TFM_RES_MASK);

	child = ctx->child;

	/* data cipher, uses Key1 i.e. the first half of *key */
	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
				       CRYPTO_TFM_REQ_MASK);
	err = crypto_cipher_setkey(child, key, keylen/2);
	if (err)
		return err;

	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
				     CRYPTO_TFM_RES_MASK);

	return 0;
}

struct sinfo {
	be128 *t;
	struct crypto_tfm *tfm;
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *);
};

static inline void xts_round(struct sinfo *s, void *dst, const void *src)
{
	be128_xor(dst, s->t, src);		/* PP <- T xor P */
	s->fn(s->tfm, dst, dst);		/* CC <- E(Key1,PP) */
	be128_xor(dst, dst, s->t);		/* C <- T xor CC */
}

static int crypt(struct blkcipher_desc *d,
		 struct blkcipher_walk *w, struct priv *ctx,
		 void (*tw)(struct crypto_tfm *, u8 *, const u8 *),
		 void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
{
	int err;
	unsigned int avail;
	const int bs = XTS_BLOCK_SIZE;
	struct sinfo s = {
		.tfm = crypto_cipher_tfm(ctx->child),
		.fn = fn
	};
	u8 *wsrc;
	u8 *wdst;

	err = blkcipher_walk_virt(d, w);
	if (!w->nbytes)
		return err;

	s.t = (be128 *)w->iv;
	avail = w->nbytes;

	wsrc = w->src.virt.addr;
	wdst = w->dst.virt.addr;

	/* calculate first value of T */
	tw(crypto_cipher_tfm(ctx->tweak), w->iv, w->iv);

	goto first;

	for (;;) {
		do {
			gf128mul_x_ble(s.t, s.t);

first:
			xts_round(&s, wdst, wsrc);

			wsrc += bs;
			wdst += bs;
		} while ((avail -= bs) >= bs);

		err = blkcipher_walk_done(d, w, avail);
		if (!w->nbytes)
			break;

		avail = w->nbytes;

		wsrc = w->src.virt.addr;
		wdst = w->dst.virt.addr;
	}

	return err;
}

static int encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		   struct scatterlist *src, unsigned int nbytes)
{
	struct priv *ctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk w;

	blkcipher_walk_init(&w, dst, src, nbytes);
	return crypt(desc, &w, ctx, crypto_cipher_alg(ctx->tweak)->cia_encrypt,
		     crypto_cipher_alg(ctx->child)->cia_encrypt);
}

static int decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		   struct scatterlist *src, unsigned int nbytes)
{
	struct priv *ctx = crypto_blkcipher_ctx(desc->tfm);
	struct blkcipher_walk w;

	blkcipher_walk_init(&w, dst, src, nbytes);
	return crypt(desc, &w, ctx, crypto_cipher_alg(ctx->tweak)->cia_encrypt,
		     crypto_cipher_alg(ctx->child)->cia_decrypt);
}

int xts_crypt(struct blkcipher_desc *desc, struct scatterlist *sdst,
	      struct scatterlist *ssrc, unsigned int nbytes,
	      struct xts_crypt_req *req)
{
	const unsigned int bsize = XTS_BLOCK_SIZE;
	const unsigned int max_blks = req->tbuflen / bsize;
	struct blkcipher_walk walk;
	unsigned int nblocks;
	be128 *src, *dst, *t;
	be128 *t_buf = req->tbuf;
	int err, i;

	BUG_ON(max_blks < 1);

	blkcipher_walk_init(&walk, sdst, ssrc, nbytes);

	err = blkcipher_walk_virt(desc, &walk);
	nbytes = walk.nbytes;
	if (!nbytes)
		return err;

	nblocks = min(nbytes / bsize, max_blks);
	src = (be128 *)walk.src.virt.addr;
	dst = (be128 *)walk.dst.virt.addr;

	/* calculate first value of T */
	req->tweak_fn(req->tweak_ctx, (u8 *)&t_buf[0], walk.iv);

	i = 0;
	goto first;

	for (;;) {
		do {
			for (i = 0; i < nblocks; i++) {
				gf128mul_x_ble(&t_buf[i], t);
first:
				t = &t_buf[i];

				/* PP <- T xor P */
				be128_xor(dst + i, t, src + i);
			}

			/* CC <- E(Key2,PP) */
			req->crypt_fn(req->crypt_ctx, (u8 *)dst,
				      nblocks * bsize);

			/* C <- T xor CC */
			for (i = 0; i < nblocks; i++)
				be128_xor(dst + i, dst + i, &t_buf[i]);

			src += nblocks;
			dst += nblocks;
			nbytes -= nblocks * bsize;
			nblocks = min(nbytes / bsize, max_blks);
		} while (nblocks > 0);

		*(be128 *)walk.iv = *t;

		err = blkcipher_walk_done(desc, &walk, nbytes);
		nbytes = walk.nbytes;
		if (!nbytes)
			break;

		nblocks = min(nbytes / bsize, max_blks);
		src = (be128 *)walk.src.virt.addr;
		dst = (be128 *)walk.dst.virt.addr;
	}

	return err;
}
EXPORT_SYMBOL_GPL(xts_crypt);

static int 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 priv *ctx = crypto_tfm_ctx(tfm);
	u32 *flags = &tfm->crt_flags;

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

	if (crypto_cipher_blocksize(cipher) != XTS_BLOCK_SIZE) {
		*flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
		crypto_free_cipher(cipher);
		return -EINVAL;
	}

	ctx->child = cipher;

	cipher = crypto_spawn_cipher(spawn);
	if (IS_ERR(cipher)) {
		crypto_free_cipher(ctx->child);
		return PTR_ERR(cipher);
	}

	/* this check isn't really needed, leave it here just in case */
	if (crypto_cipher_blocksize(cipher) != XTS_BLOCK_SIZE) {
		crypto_free_cipher(cipher);
		crypto_free_cipher(ctx->child);
		*flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
		return -EINVAL;
	}

	ctx->tweak = cipher;

	return 0;
}

static void exit_tfm(struct crypto_tfm *tfm)
{
	struct priv *ctx = crypto_tfm_ctx(tfm);
	crypto_free_cipher(ctx->child);
	crypto_free_cipher(ctx->tweak);
}

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

	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
	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);

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

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	inst->alg.cra_priority = alg->cra_priority;
	inst->alg.cra_blocksize = alg->cra_blocksize;

	if (alg->cra_alignmask < 7)
		inst->alg.cra_alignmask = 7;
	else
		inst->alg.cra_alignmask = alg->cra_alignmask;

	inst->alg.cra_type = &crypto_blkcipher_type;

	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
	inst->alg.cra_blkcipher.min_keysize =
		2 * alg->cra_cipher.cia_min_keysize;
	inst->alg.cra_blkcipher.max_keysize =
		2 * alg->cra_cipher.cia_max_keysize;

	inst->alg.cra_ctxsize = sizeof(struct priv);

	inst->alg.cra_init = init_tfm;
	inst->alg.cra_exit = exit_tfm;

	inst->alg.cra_blkcipher.setkey = setkey;
	inst->alg.cra_blkcipher.encrypt = encrypt;
	inst->alg.cra_blkcipher.decrypt = decrypt;

out_put_alg:
	crypto_mod_put(alg);
	return inst;
}

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

static struct crypto_template crypto_tmpl = {
	.name = "xts",
	.alloc = alloc,
	.free = free,
	.module = THIS_MODULE,
};

static int __init crypto_module_init(void)
{
	return crypto_register_template(&crypto_tmpl);
}

static void __exit crypto_module_exit(void)
{
	crypto_unregister_template(&crypto_tmpl);
}

module_init(crypto_module_init);
module_exit(crypto_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("XTS block cipher mode");
Commit	Line	Data
f19f5111 RS	1	/* XTS: as defined in IEEE1619/D16
	2	* http://grouper.ieee.org/groups/1619/email/pdf00086.pdf
	3	* (sector sizes which are not a multiple of 16 bytes are,
	4	* however currently unsupported)
	5	*
	6	* Copyright (c) 2007 Rik Snel <[email protected]>
	7	*
	8	* Based om ecb.c
	9	* Copyright (c) 2006 Herbert Xu <[email protected]>
	10	*
	11	* This program is free software; you can redistribute it and/or modify it
	12	* under the terms of the GNU General Public License as published by the Free
	13	* Software Foundation; either version 2 of the License, or (at your option)
	14	* any later version.
	15	*/
	16	#include <crypto/algapi.h>
	17	#include <linux/err.h>
	18	#include <linux/init.h>
	19	#include <linux/kernel.h>
	20	#include <linux/module.h>
	21	#include <linux/scatterlist.h>
	22	#include <linux/slab.h>
	23
ce004556	24	#include <crypto/xts.h>
f19f5111 RS	25	#include <crypto/b128ops.h>
	26	#include <crypto/gf128mul.h>
	27
	28	struct priv {
	29	struct crypto_cipher *child;
	30	struct crypto_cipher *tweak;
	31	};
	32
	33	static int setkey(struct crypto_tfm parent, const u8 key,
	34	unsigned int keylen)
	35	{
	36	struct priv *ctx = crypto_tfm_ctx(parent);
	37	struct crypto_cipher *child = ctx->tweak;
	38	u32 *flags = &parent->crt_flags;
	39	int err;
	40
	41	/* key consists of keys of equal size concatenated, therefore
	42	* the length must be even */
	43	if (keylen % 2) {
	44	/* tell the user why there was an error */
	45	*flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
	46	return -EINVAL;
	47	}
	48
25985edc	49	/* we need two cipher instances: one to compute the initial 'tweak'
f19f5111 RS	50	* by encrypting the IV (usually the 'plain' iv) and the other
	51	* one to encrypt and decrypt the data */
	52
	53	/* tweak cipher, uses Key2 i.e. the second half of key /
	54	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	55	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
	56	CRYPTO_TFM_REQ_MASK);
	57	err = crypto_cipher_setkey(child, key + keylen/2, keylen/2);
	58	if (err)
	59	return err;
	60
	61	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
	62	CRYPTO_TFM_RES_MASK);
	63
	64	child = ctx->child;
	65
	66	/* data cipher, uses Key1 i.e. the first half of key /
	67	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	68	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
	69	CRYPTO_TFM_REQ_MASK);
	70	err = crypto_cipher_setkey(child, key, keylen/2);
	71	if (err)
	72	return err;
	73
	74	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
	75	CRYPTO_TFM_RES_MASK);
	76
	77	return 0;
	78	}
	79
	80	struct sinfo {
6212f2c7	81	be128 *t;
f19f5111 RS	82	struct crypto_tfm *tfm;
	83	void (fn)(struct crypto_tfm , u8 , const u8 );
	84	};
	85
	86	static inline void xts_round(struct sinfo s, void dst, const void *src)
	87	{
6212f2c7	88	be128_xor(dst, s->t, src); /* PP <- T xor P */
f19f5111	89	s->fn(s->tfm, dst, dst); /* CC <- E(Key1,PP) */
6212f2c7	90	be128_xor(dst, dst, s->t); /* C <- T xor CC */
f19f5111 RS	91	}
	92
	93	static int crypt(struct blkcipher_desc *d,
	94	struct blkcipher_walk w, struct priv ctx,
	95	void (tw)(struct crypto_tfm , u8 , const u8 ),
	96	void (fn)(struct crypto_tfm , u8 , const u8 ))
	97	{
	98	int err;
	99	unsigned int avail;
f9d2691f	100	const int bs = XTS_BLOCK_SIZE;
f19f5111 RS	101	struct sinfo s = {
	102	.tfm = crypto_cipher_tfm(ctx->child),
	103	.fn = fn
	104	};
f19f5111 RS	105	u8 *wsrc;
	106	u8 *wdst;
	107
	108	err = blkcipher_walk_virt(d, w);
	109	if (!w->nbytes)
	110	return err;
	111
6212f2c7	112	s.t = (be128 *)w->iv;
f19f5111 RS	113	avail = w->nbytes;
	114
	115	wsrc = w->src.virt.addr;
	116	wdst = w->dst.virt.addr;
	117
	118	/* calculate first value of T */
6212f2c7	119	tw(crypto_cipher_tfm(ctx->tweak), w->iv, w->iv);
f19f5111 RS	120
	121	goto first;
	122
	123	for (;;) {
	124	do {
6212f2c7	125	gf128mul_x_ble(s.t, s.t);
f19f5111 RS	126
	127	first:
	128	xts_round(&s, wdst, wsrc);
	129
	130	wsrc += bs;
	131	wdst += bs;
	132	} while ((avail -= bs) >= bs);
	133
	134	err = blkcipher_walk_done(d, w, avail);
	135	if (!w->nbytes)
	136	break;
	137
	138	avail = w->nbytes;
	139
	140	wsrc = w->src.virt.addr;
	141	wdst = w->dst.virt.addr;
	142	}
	143
	144	return err;
	145	}
	146
	147	static int encrypt(struct blkcipher_desc desc, struct scatterlist dst,
	148	struct scatterlist *src, unsigned int nbytes)
	149	{
	150	struct priv *ctx = crypto_blkcipher_ctx(desc->tfm);
	151	struct blkcipher_walk w;
	152
	153	blkcipher_walk_init(&w, dst, src, nbytes);
	154	return crypt(desc, &w, ctx, crypto_cipher_alg(ctx->tweak)->cia_encrypt,
	155	crypto_cipher_alg(ctx->child)->cia_encrypt);
	156	}
	157
	158	static int decrypt(struct blkcipher_desc desc, struct scatterlist dst,
	159	struct scatterlist *src, unsigned int nbytes)
	160	{
	161	struct priv *ctx = crypto_blkcipher_ctx(desc->tfm);
	162	struct blkcipher_walk w;
	163
	164	blkcipher_walk_init(&w, dst, src, nbytes);
	165	return crypt(desc, &w, ctx, crypto_cipher_alg(ctx->tweak)->cia_encrypt,
	166	crypto_cipher_alg(ctx->child)->cia_decrypt);
	167	}
	168
ce004556 JK	169	int xts_crypt(struct blkcipher_desc desc, struct scatterlist sdst,
	170	struct scatterlist *ssrc, unsigned int nbytes,
	171	struct xts_crypt_req *req)
	172	{
	173	const unsigned int bsize = XTS_BLOCK_SIZE;
	174	const unsigned int max_blks = req->tbuflen / bsize;
	175	struct blkcipher_walk walk;
	176	unsigned int nblocks;
	177	be128 src, dst, *t;
	178	be128 *t_buf = req->tbuf;
	179	int err, i;
	180
	181	BUG_ON(max_blks < 1);
	182
	183	blkcipher_walk_init(&walk, sdst, ssrc, nbytes);
	184
	185	err = blkcipher_walk_virt(desc, &walk);
	186	nbytes = walk.nbytes;
	187	if (!nbytes)
	188	return err;
	189
	190	nblocks = min(nbytes / bsize, max_blks);
	191	src = (be128 *)walk.src.virt.addr;
	192	dst = (be128 *)walk.dst.virt.addr;
	193
	194	/* calculate first value of T */
	195	req->tweak_fn(req->tweak_ctx, (u8 *)&t_buf[0], walk.iv);
	196
	197	i = 0;
	198	goto first;
	199
	200	for (;;) {
	201	do {
	202	for (i = 0; i < nblocks; i++) {
	203	gf128mul_x_ble(&t_buf[i], t);
	204	first:
	205	t = &t_buf[i];
	206
	207	/* PP <- T xor P */
	208	be128_xor(dst + i, t, src + i);
	209	}
	210
	211	/* CC <- E(Key2,PP) */
	212	req->crypt_fn(req->crypt_ctx, (u8 *)dst,
	213	nblocks * bsize);
	214
	215	/* C <- T xor CC */
	216	for (i = 0; i < nblocks; i++)
	217	be128_xor(dst + i, dst + i, &t_buf[i]);
	218
	219	src += nblocks;
	220	dst += nblocks;
	221	nbytes -= nblocks * bsize;
	222	nblocks = min(nbytes / bsize, max_blks);
	223	} while (nblocks > 0);
	224
	225	(be128 )walk.iv = *t;
	226
	227	err = blkcipher_walk_done(desc, &walk, nbytes);
	228	nbytes = walk.nbytes;
	229	if (!nbytes)
	230	break;
	231
	232	nblocks = min(nbytes / bsize, max_blks);
233	src = (be128 *)walk.src.virt.addr;
234	dst = (be128 *)walk.dst.virt.addr;
235	}
236
237	return err;
238	}
239	EXPORT_SYMBOL_GPL(xts_crypt);
240
f19f5111 RS	241	static int init_tfm(struct crypto_tfm *tfm)
	242	{
	243	struct crypto_cipher *cipher;
	244	struct crypto_instance inst = (void )tfm->__crt_alg;
	245	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	246	struct priv *ctx = crypto_tfm_ctx(tfm);
	247	u32 *flags = &tfm->crt_flags;
	248
	249	cipher = crypto_spawn_cipher(spawn);
	250	if (IS_ERR(cipher))
	251	return PTR_ERR(cipher);
	252
f9d2691f	253	if (crypto_cipher_blocksize(cipher) != XTS_BLOCK_SIZE) {
f19f5111 RS	254	*flags \|= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
	255	crypto_free_cipher(cipher);
	256	return -EINVAL;
	257	}
	258
	259	ctx->child = cipher;
	260
	261	cipher = crypto_spawn_cipher(spawn);
	262	if (IS_ERR(cipher)) {
	263	crypto_free_cipher(ctx->child);
	264	return PTR_ERR(cipher);
	265	}
	266
	267	/* this check isn't really needed, leave it here just in case */
f9d2691f	268	if (crypto_cipher_blocksize(cipher) != XTS_BLOCK_SIZE) {
f19f5111 RS	269	crypto_free_cipher(cipher);
	270	crypto_free_cipher(ctx->child);
	271	*flags \|= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
	272	return -EINVAL;
	273	}
	274
	275	ctx->tweak = cipher;
	276
	277	return 0;
	278	}
	279
	280	static void exit_tfm(struct crypto_tfm *tfm)
	281	{
	282	struct priv *ctx = crypto_tfm_ctx(tfm);
	283	crypto_free_cipher(ctx->child);
	284	crypto_free_cipher(ctx->tweak);
	285	}
	286
	287	static struct crypto_instance alloc(struct rtattr *tb)
	288	{
	289	struct crypto_instance *inst;
	290	struct crypto_alg *alg;
	291	int err;
	292
	293	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
	294	if (err)
	295	return ERR_PTR(err);
	296
	297	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
	298	CRYPTO_ALG_TYPE_MASK);
	299	if (IS_ERR(alg))
8db05078	300	return ERR_CAST(alg);
f19f5111 RS	301
	302	inst = crypto_alloc_instance("xts", alg);
	303	if (IS_ERR(inst))
	304	goto out_put_alg;
	305
	306	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	307	inst->alg.cra_priority = alg->cra_priority;
	308	inst->alg.cra_blocksize = alg->cra_blocksize;
	309
	310	if (alg->cra_alignmask < 7)
	311	inst->alg.cra_alignmask = 7;
	312	else
	313	inst->alg.cra_alignmask = alg->cra_alignmask;
	314
	315	inst->alg.cra_type = &crypto_blkcipher_type;
	316
	317	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
	318	inst->alg.cra_blkcipher.min_keysize =
	319	2 * alg->cra_cipher.cia_min_keysize;
	320	inst->alg.cra_blkcipher.max_keysize =
	321	2 * alg->cra_cipher.cia_max_keysize;
	322
	323	inst->alg.cra_ctxsize = sizeof(struct priv);
	324
	325	inst->alg.cra_init = init_tfm;
	326	inst->alg.cra_exit = exit_tfm;
	327
	328	inst->alg.cra_blkcipher.setkey = setkey;
	329	inst->alg.cra_blkcipher.encrypt = encrypt;
	330	inst->alg.cra_blkcipher.decrypt = decrypt;
	331
	332	out_put_alg:
	333	crypto_mod_put(alg);
	334	return inst;
	335	}
	336
	337	static void free(struct crypto_instance *inst)
	338	{
	339	crypto_drop_spawn(crypto_instance_ctx(inst));
	340	kfree(inst);
	341	}
	342
	343	static struct crypto_template crypto_tmpl = {
	344	.name = "xts",
	345	.alloc = alloc,
	346	.free = free,
	347	.module = THIS_MODULE,
	348	};
	349
	350	static int __init crypto_module_init(void)
	351	{
	352	return crypto_register_template(&crypto_tmpl);
	353	}
	354
	355	static void __exit crypto_module_exit(void)
	356	{
	357	crypto_unregister_template(&crypto_tmpl);
	358	}
	359
	360	module_init(crypto_module_init);
	361	module_exit(crypto_module_exit);
	362
	363	MODULE_LICENSE("GPL");
	364	MODULE_DESCRIPTION("XTS block cipher mode");