[mirror_ubuntu-bionic-kernel.git] / crypto / lrw.c

/* LRW: as defined by Cyril Guyot in
 *	http://grouper.ieee.org/groups/1619/email/pdf00017.pdf
 *
 * Copyright (c) 2006 Rik Snel <rsnel@cube.dyndns.org>
 *
 * Based on ecb.c
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * 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 implementation is checked against the test vectors in the above
 * document and by a test vector provided by Ken Buchanan at
 * http://www.mail-archive.com/stds-p1619@listserv.ieee.org/msg00173.html
 *
 * The test vectors are included in the testing module tcrypt.[ch] */

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

struct priv {
	struct crypto_cipher *child;
	struct lrw_table_ctx table;
};

static inline void setbit128_bbe(void *b, int bit)
{
	__set_bit(bit ^ (0x80 -
#ifdef __BIG_ENDIAN
			 BITS_PER_LONG
#else
			 BITS_PER_BYTE
#endif
			), b);
}

int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak)
{
	be128 tmp = { 0 };
	int i;

	if (ctx->table)
		gf128mul_free_64k(ctx->table);

	/* initialize multiplication table for Key2 */
	ctx->table = gf128mul_init_64k_bbe((be128 *)tweak);
	if (!ctx->table)
		return -ENOMEM;

	/* initialize optimization table */
	for (i = 0; i < 128; i++) {
		setbit128_bbe(&tmp, i);
		ctx->mulinc[i] = tmp;
		gf128mul_64k_bbe(&ctx->mulinc[i], ctx->table);
	}

	return 0;
}
EXPORT_SYMBOL_GPL(lrw_init_table);

void lrw_free_table(struct lrw_table_ctx *ctx)
{
	if (ctx->table)
		gf128mul_free_64k(ctx->table);
}
EXPORT_SYMBOL_GPL(lrw_free_table);

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->child;
	int err, bsize = LRW_BLOCK_SIZE;
	const u8 *tweak = key + keylen - bsize;

	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 - bsize);
	if (err)
		return err;
	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
				     CRYPTO_TFM_RES_MASK);

	return lrw_init_table(&ctx->table, tweak);
}

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

static inline void inc(be128 *iv)
{
	be64_add_cpu(&iv->b, 1);
	if (!iv->b)
		be64_add_cpu(&iv->a, 1);
}

static inline void lrw_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(Key2,PP) */
	be128_xor(dst, dst, &s->t);		/* C <- T xor CC */
}

/* this returns the number of consequative 1 bits starting
 * from the right, get_index128(00 00 00 00 00 00 ... 00 00 10 FB) = 2 */
static inline int get_index128(be128 *block)
{
	int x;
	__be32 *p = (__be32 *) block;

	for (p += 3, x = 0; x < 128; p--, x += 32) {
		u32 val = be32_to_cpup(p);

		if (!~val)
			continue;

		return x + ffz(val);
	}

	return x;
}

static int crypt(struct blkcipher_desc *d,
		 struct blkcipher_walk *w, struct priv *ctx,
		 void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
{
	int err;
	unsigned int avail;
	const int bs = LRW_BLOCK_SIZE;
	struct sinfo s = {
		.tfm = crypto_cipher_tfm(ctx->child),
		.fn = fn
	};
	be128 *iv;
	u8 *wsrc;
	u8 *wdst;

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

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

	/* calculate first value of T */
	iv = (be128 *)w->iv;
	s.t = *iv;

	/* T <- I*Key2 */
	gf128mul_64k_bbe(&s.t, ctx->table.table);

	goto first;

	for (;;) {
		do {
			/* T <- I*Key2, using the optimization
			 * discussed in the specification */
			be128_xor(&s.t, &s.t,
				  &ctx->table.mulinc[get_index128(iv)]);
			inc(iv);

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

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

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

		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->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->child)->cia_decrypt);
}

int lrw_crypt(struct blkcipher_desc *desc, struct scatterlist *sdst,
	      struct scatterlist *ssrc, unsigned int nbytes,
	      struct lrw_crypt_req *req)
{
	const unsigned int bsize = LRW_BLOCK_SIZE;
	const unsigned int max_blks = req->tbuflen / bsize;
	struct lrw_table_ctx *ctx = req->table_ctx;
	struct blkcipher_walk walk;
	unsigned int nblocks;
	be128 *iv, *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(walk.nbytes / bsize, max_blks);
	src = (be128 *)walk.src.virt.addr;
	dst = (be128 *)walk.dst.virt.addr;

	/* calculate first value of T */
	iv = (be128 *)walk.iv;
	t_buf[0] = *iv;

	/* T <- I*Key2 */
	gf128mul_64k_bbe(&t_buf[0], ctx->table);

	i = 0;
	goto first;

	for (;;) {
		do {
			for (i = 0; i < nblocks; i++) {
				/* T <- I*Key2, using the optimization
				 * discussed in the specification */
				be128_xor(&t_buf[i], t,
						&ctx->mulinc[get_index128(iv)]);
				inc(iv);
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);

		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(lrw_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) != LRW_BLOCK_SIZE) {
		*flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
		crypto_free_cipher(cipher);
		return -EINVAL;
	}

	ctx->child = cipher;
	return 0;
}

static void exit_tfm(struct crypto_tfm *tfm)
{
	struct priv *ctx = crypto_tfm_ctx(tfm);

	lrw_free_table(&ctx->table);
	crypto_free_cipher(ctx->child);
}

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("lrw", 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;

	if (!(alg->cra_blocksize % 4))
		inst->alg.cra_alignmask |= 3;
	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
	inst->alg.cra_blkcipher.min_keysize =
		alg->cra_cipher.cia_min_keysize + alg->cra_blocksize;
	inst->alg.cra_blkcipher.max_keysize =
		alg->cra_cipher.cia_max_keysize + alg->cra_blocksize;

	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 = "lrw",
	.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("LRW block cipher mode");
Commit	Line	Data
64470f1b RS	1	/* LRW: as defined by Cyril Guyot in
	2	* http://grouper.ieee.org/groups/1619/email/pdf00017.pdf
	3	*
	4	* Copyright (c) 2006 Rik Snel <rsnel@cube.dyndns.org>
	5	*
6c2205b8	6	* Based on ecb.c
64470f1b RS	7	* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
	8	*
	9	* This program is free software; you can redistribute it and/or modify it
	10	* under the terms of the GNU General Public License as published by the Free
	11	* Software Foundation; either version 2 of the License, or (at your option)
	12	* any later version.
	13	*/
	14	/* This implementation is checked against the test vectors in the above
	15	* document and by a test vector provided by Ken Buchanan at
	16	* http://www.mail-archive.com/stds-p1619@listserv.ieee.org/msg00173.html
	17	*
	18	* The test vectors are included in the testing module tcrypt.[ch] */
6c2205b8	19
64470f1b RS	20	#include <crypto/algapi.h>
	21	#include <linux/err.h>
	22	#include <linux/init.h>
	23	#include <linux/kernel.h>
	24	#include <linux/module.h>
	25	#include <linux/scatterlist.h>
	26	#include <linux/slab.h>
	27
	28	#include <crypto/b128ops.h>
	29	#include <crypto/gf128mul.h>
6c2205b8	30	#include <crypto/lrw.h>
64470f1b	31
171c0204 JK	32	struct priv {
	33	struct crypto_cipher *child;
	34	struct lrw_table_ctx table;
	35	};
	36
64470f1b RS	37	static inline void setbit128_bbe(void *b, int bit)
64470f1b RS	38	{
8eb2dfac HX	39	__set_bit(bit ^ (0x80 -
	40	#ifdef __BIG_ENDIAN
	41	BITS_PER_LONG
	42	#else
	43	BITS_PER_BYTE
	44	#endif
	45	), b);
64470f1b RS	46	}
64470f1b RS	47
6c2205b8	48	int lrw_init_table(struct lrw_table_ctx ctx, const u8 tweak)
64470f1b	49	{
64470f1b	50	be128 tmp = { 0 };
171c0204	51	int i;
64470f1b RS	52
	53	if (ctx->table)
	54	gf128mul_free_64k(ctx->table);
	55
	56	/* initialize multiplication table for Key2 */
171c0204	57	ctx->table = gf128mul_init_64k_bbe((be128 *)tweak);
64470f1b RS	58	if (!ctx->table)
	59	return -ENOMEM;
	60
	61	/* initialize optimization table */
	62	for (i = 0; i < 128; i++) {
	63	setbit128_bbe(&tmp, i);
	64	ctx->mulinc[i] = tmp;
	65	gf128mul_64k_bbe(&ctx->mulinc[i], ctx->table);
	66	}
	67
	68	return 0;
	69	}
6c2205b8	70	EXPORT_SYMBOL_GPL(lrw_init_table);
64470f1b	71
6c2205b8	72	void lrw_free_table(struct lrw_table_ctx *ctx)
171c0204 JK	73	{
	74	if (ctx->table)
	75	gf128mul_free_64k(ctx->table);
	76	}
6c2205b8	77	EXPORT_SYMBOL_GPL(lrw_free_table);
171c0204 JK	78
	79	static int setkey(struct crypto_tfm parent, const u8 key,
	80	unsigned int keylen)
	81	{
	82	struct priv *ctx = crypto_tfm_ctx(parent);
	83	struct crypto_cipher *child = ctx->child;
	84	int err, bsize = LRW_BLOCK_SIZE;
	85	const u8 *tweak = key + keylen - bsize;
	86
	87	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	88	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
	89	CRYPTO_TFM_REQ_MASK);
	90	err = crypto_cipher_setkey(child, key, keylen - bsize);
	91	if (err)
	92	return err;
	93	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
	94	CRYPTO_TFM_RES_MASK);
	95
	96	return lrw_init_table(&ctx->table, tweak);
	97	}
	98
64470f1b RS	99	struct sinfo {
	100	be128 t;
	101	struct crypto_tfm *tfm;
	102	void (fn)(struct crypto_tfm , u8 , const u8 );
	103	};
	104
	105	static inline void inc(be128 *iv)
	106	{
fd4609a8 MS	107	be64_add_cpu(&iv->b, 1);
	108	if (!iv->b)
	109	be64_add_cpu(&iv->a, 1);
64470f1b RS	110	}
64470f1b RS	111
9ebed9d1	112	static inline void lrw_round(struct sinfo s, void dst, const void *src)
64470f1b RS	113	{
	114	be128_xor(dst, &s->t, src); /* PP <- T xor P */
	115	s->fn(s->tfm, dst, dst); /* CC <- E(Key2,PP) */
	116	be128_xor(dst, dst, &s->t); /* C <- T xor CC */
	117	}
	118
	119	/* this returns the number of consequative 1 bits starting
	120	* from the right, get_index128(00 00 00 00 00 00 ... 00 00 10 FB) = 2 */
	121	static inline int get_index128(be128 *block)
	122	{
	123	int x;
	124	__be32 p = (__be32 ) block;
	125
	126	for (p += 3, x = 0; x < 128; p--, x += 32) {
	127	u32 val = be32_to_cpup(p);
	128
	129	if (!~val)
	130	continue;
	131
	132	return x + ffz(val);
	133	}
	134
	135	return x;
	136	}
	137
	138	static int crypt(struct blkcipher_desc *d,
	139	struct blkcipher_walk w, struct priv ctx,
	140	void (fn)(struct crypto_tfm , u8 , const u8 ))
	141	{
	142	int err;
	143	unsigned int avail;
4660720d	144	const int bs = LRW_BLOCK_SIZE;
64470f1b RS	145	struct sinfo s = {
	146	.tfm = crypto_cipher_tfm(ctx->child),
	147	.fn = fn
	148	};
	149	be128 *iv;
	150	u8 *wsrc;
	151	u8 *wdst;
	152
	153	err = blkcipher_walk_virt(d, w);
	154	if (!(avail = w->nbytes))
	155	return err;
	156
	157	wsrc = w->src.virt.addr;
	158	wdst = w->dst.virt.addr;
	159
	160	/* calculate first value of T */
	161	iv = (be128 *)w->iv;
	162	s.t = *iv;
	163
	164	/* T <- IKey2 /
171c0204	165	gf128mul_64k_bbe(&s.t, ctx->table.table);
64470f1b RS	166
	167	goto first;
	168
	169	for (;;) {
	170	do {
	171	/* T <- I*Key2, using the optimization
	172	* discussed in the specification */
171c0204 JK	173	be128_xor(&s.t, &s.t,
171c0204 JK	174	&ctx->table.mulinc[get_index128(iv)]);
64470f1b RS	175	inc(iv);
	176
	177	first:
9ebed9d1	178	lrw_round(&s, wdst, wsrc);
64470f1b RS	179
	180	wsrc += bs;
	181	wdst += bs;
	182	} while ((avail -= bs) >= bs);
	183
	184	err = blkcipher_walk_done(d, w, avail);
	185	if (!(avail = w->nbytes))
	186	break;
	187
	188	wsrc = w->src.virt.addr;
	189	wdst = w->dst.virt.addr;
	190	}
	191
	192	return err;
	193	}
	194
	195	static int encrypt(struct blkcipher_desc desc, struct scatterlist dst,
	196	struct scatterlist *src, unsigned int nbytes)
	197	{
	198	struct priv *ctx = crypto_blkcipher_ctx(desc->tfm);
	199	struct blkcipher_walk w;
	200
	201	blkcipher_walk_init(&w, dst, src, nbytes);
	202	return crypt(desc, &w, ctx,
	203	crypto_cipher_alg(ctx->child)->cia_encrypt);
	204	}
	205
	206	static int decrypt(struct blkcipher_desc desc, struct scatterlist dst,
	207	struct scatterlist *src, unsigned int nbytes)
	208	{
	209	struct priv *ctx = crypto_blkcipher_ctx(desc->tfm);
	210	struct blkcipher_walk w;
	211
	212	blkcipher_walk_init(&w, dst, src, nbytes);
	213	return crypt(desc, &w, ctx,
	214	crypto_cipher_alg(ctx->child)->cia_decrypt);
	215	}
	216
6c2205b8 JK	217	int lrw_crypt(struct blkcipher_desc desc, struct scatterlist sdst,
	218	struct scatterlist *ssrc, unsigned int nbytes,
	219	struct lrw_crypt_req *req)
	220	{
	221	const unsigned int bsize = LRW_BLOCK_SIZE;
	222	const unsigned int max_blks = req->tbuflen / bsize;
	223	struct lrw_table_ctx *ctx = req->table_ctx;
	224	struct blkcipher_walk walk;
	225	unsigned int nblocks;
	226	be128 iv, src, dst, t;
	227	be128 *t_buf = req->tbuf;
	228	int err, i;
	229
	230	BUG_ON(max_blks < 1);
	231
	232	blkcipher_walk_init(&walk, sdst, ssrc, nbytes);
	233
	234	err = blkcipher_walk_virt(desc, &walk);
	235	nbytes = walk.nbytes;
	236	if (!nbytes)
	237	return err;
	238
	239	nblocks = min(walk.nbytes / bsize, max_blks);
	240	src = (be128 *)walk.src.virt.addr;
	241	dst = (be128 *)walk.dst.virt.addr;
	242
	243	/* calculate first value of T */
	244	iv = (be128 *)walk.iv;
	245	t_buf[0] = *iv;
	246
	247	/* T <- IKey2 /
	248	gf128mul_64k_bbe(&t_buf[0], ctx->table);
	249
	250	i = 0;
	251	goto first;
	252
	253	for (;;) {
	254	do {
	255	for (i = 0; i < nblocks; i++) {
	256	/* T <- I*Key2, using the optimization
	257	* discussed in the specification */
	258	be128_xor(&t_buf[i], t,
	259	&ctx->mulinc[get_index128(iv)]);
	260	inc(iv);
	261	first:
	262	t = &t_buf[i];
	263
	264	/* PP <- T xor P */
	265	be128_xor(dst + i, t, src + i);
	266	}
	267
	268	/* CC <- E(Key2,PP) */
	269	req->crypt_fn(req->crypt_ctx, (u8 *)dst,
	270	nblocks * bsize);
	271
	272	/* C <- T xor CC */
	273	for (i = 0; i < nblocks; i++)
	274	be128_xor(dst + i, dst + i, &t_buf[i]);
	275
	276	src += nblocks;
	277	dst += nblocks;
	278	nbytes -= nblocks * bsize;
	279	nblocks = min(nbytes / bsize, max_blks);
	280	} while (nblocks > 0);
281
282	err = blkcipher_walk_done(desc, &walk, nbytes);
283	nbytes = walk.nbytes;
284	if (!nbytes)
285	break;
286
287	nblocks = min(nbytes / bsize, max_blks);
288	src = (be128 *)walk.src.virt.addr;
289	dst = (be128 *)walk.dst.virt.addr;
290	}
291
292	return err;
293	}
294	EXPORT_SYMBOL_GPL(lrw_crypt);
295
64470f1b RS	296	static int init_tfm(struct crypto_tfm *tfm)
64470f1b RS	297	{
2e306ee0	298	struct crypto_cipher *cipher;
64470f1b RS	299	struct crypto_instance inst = (void )tfm->__crt_alg;
	300	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	301	struct priv *ctx = crypto_tfm_ctx(tfm);
	302	u32 *flags = &tfm->crt_flags;
	303
2e306ee0 HX	304	cipher = crypto_spawn_cipher(spawn);
	305	if (IS_ERR(cipher))
	306	return PTR_ERR(cipher);
64470f1b	307
4660720d	308	if (crypto_cipher_blocksize(cipher) != LRW_BLOCK_SIZE) {
64470f1b	309	*flags \|= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
b884f8b9	310	crypto_free_cipher(cipher);
64470f1b RS	311	return -EINVAL;
	312	}
	313
2e306ee0	314	ctx->child = cipher;
64470f1b RS	315	return 0;
	316	}
	317
	318	static void exit_tfm(struct crypto_tfm *tfm)
	319	{
	320	struct priv *ctx = crypto_tfm_ctx(tfm);
171c0204 JK	321
171c0204 JK	322	lrw_free_table(&ctx->table);
64470f1b RS	323	crypto_free_cipher(ctx->child);
	324	}
	325
ebc610e5	326	static struct crypto_instance alloc(struct rtattr *tb)
64470f1b RS	327	{
	328	struct crypto_instance *inst;
	329	struct crypto_alg *alg;
ebc610e5 HX	330	int err;
	331
	332	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
	333	if (err)
	334	return ERR_PTR(err);
64470f1b	335
ebc610e5 HX	336	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
ebc610e5 HX	337	CRYPTO_ALG_TYPE_MASK);
64470f1b	338	if (IS_ERR(alg))
e231c2ee	339	return ERR_CAST(alg);
64470f1b RS	340
	341	inst = crypto_alloc_instance("lrw", alg);
	342	if (IS_ERR(inst))
	343	goto out_put_alg;
	344
	345	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	346	inst->alg.cra_priority = alg->cra_priority;
	347	inst->alg.cra_blocksize = alg->cra_blocksize;
	348
	349	if (alg->cra_alignmask < 7) inst->alg.cra_alignmask = 7;
	350	else inst->alg.cra_alignmask = alg->cra_alignmask;
	351	inst->alg.cra_type = &crypto_blkcipher_type;
	352
	353	if (!(alg->cra_blocksize % 4))
	354	inst->alg.cra_alignmask \|= 3;
	355	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
	356	inst->alg.cra_blkcipher.min_keysize =
	357	alg->cra_cipher.cia_min_keysize + alg->cra_blocksize;
	358	inst->alg.cra_blkcipher.max_keysize =
	359	alg->cra_cipher.cia_max_keysize + alg->cra_blocksize;
	360
	361	inst->alg.cra_ctxsize = sizeof(struct priv);
	362
	363	inst->alg.cra_init = init_tfm;
	364	inst->alg.cra_exit = exit_tfm;
	365
	366	inst->alg.cra_blkcipher.setkey = setkey;
	367	inst->alg.cra_blkcipher.encrypt = encrypt;
	368	inst->alg.cra_blkcipher.decrypt = decrypt;
	369
	370	out_put_alg:
	371	crypto_mod_put(alg);
	372	return inst;
	373	}
	374
	375	static void free(struct crypto_instance *inst)
	376	{
	377	crypto_drop_spawn(crypto_instance_ctx(inst));
	378	kfree(inst);
	379	}
	380
	381	static struct crypto_template crypto_tmpl = {
	382	.name = "lrw",
	383	.alloc = alloc,
	384	.free = free,
	385	.module = THIS_MODULE,
	386	};
	387
	388	static int __init crypto_module_init(void)
	389	{
	390	return crypto_register_template(&crypto_tmpl);
	391	}
	392
	393	static void __exit crypto_module_exit(void)
	394	{
	395	crypto_unregister_template(&crypto_tmpl);
	396	}
	397
	398	module_init(crypto_module_init);
	399	module_exit(crypto_module_exit);
	400
	401	MODULE_LICENSE("GPL");
	402	MODULE_DESCRIPTION("LRW block cipher mode");