[GitHub/mt8127/android_kernel_alcatel_ttab.git] / crypto / ctr.c

/*
 * CTR: Counter mode
 *
 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
 *
 * 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/random.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>

struct ctr_instance_ctx {
	struct crypto_spawn alg;
	unsigned int noncesize;
	unsigned int ivsize;
	unsigned int countersize;
};

struct crypto_ctr_ctx {
	struct crypto_cipher *child;
	u8 *nonce;
};

static inline void __ctr_inc_byte(u8 *a, unsigned int size)
{
	u8 *b = (a + size);
	u8 c;

	for (; size; size--) {
		c = *--b + 1;
		*b = c;
		if (c)
			break;
	}
}

static void ctr_inc_quad(u8 *a, unsigned int size)
{
	__be32 *b = (__be32 *)(a + size);
	u32 c;

	for (; size >= 4; size -=4) {
		c = be32_to_cpu(*--b) + 1;
		*b = cpu_to_be32(c);
		if (c)
			return;
	}

	__ctr_inc_byte(a, size);
}

static void xor_byte(u8 *a, const u8 *b, unsigned int bs)
{
	for (; bs; bs--)
		*a++ ^= *b++;
}

static void xor_quad(u8 *dst, const u8 *src, unsigned int bs)
{
	u32 *a = (u32 *)dst;
	u32 *b = (u32 *)src;

	for (; bs >= 4; bs -= 4)
		*a++ ^= *b++;

	xor_byte((u8 *)a, (u8 *)b, bs);
}

static int crypto_ctr_setkey(struct crypto_tfm *parent, const u8 *key,
			     unsigned int keylen)
{
	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(parent);
	struct crypto_cipher *child = ctx->child;
	struct ctr_instance_ctx *ictx =
		crypto_instance_ctx(crypto_tfm_alg_instance(parent));
	unsigned int noncelen = ictx->noncesize;
	int err = 0;

	/* the nonce is stored in bytes at end of key */
	if (keylen < noncelen)
		return  -EINVAL;

	memcpy(ctx->nonce, key + (keylen - noncelen), noncelen);

	keylen -=  noncelen;

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

	return err;
}

static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
				    struct crypto_cipher *tfm, u8 *ctrblk,
				    unsigned int countersize)
{
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
		   crypto_cipher_alg(tfm)->cia_encrypt;
	unsigned int bsize = crypto_cipher_blocksize(tfm);
	unsigned long alignmask = crypto_cipher_alignmask(tfm);
	u8 ks[bsize + alignmask];
	u8 *keystream = (u8 *)ALIGN((unsigned long)ks, alignmask + 1);
	u8 *src = walk->src.virt.addr;
	u8 *dst = walk->dst.virt.addr;
	unsigned int nbytes = walk->nbytes;

	do {
		/* create keystream */
		fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
		xor_quad(keystream, src, min(nbytes, bsize));

		/* copy result into dst */
		memcpy(dst, keystream, min(nbytes, bsize));

		/* increment counter in counterblock */
		ctr_inc_quad(ctrblk + (bsize - countersize), countersize);

		if (nbytes < bsize)
			break;

		src += bsize;
		dst += bsize;
		nbytes -= bsize;

	} while (nbytes);

	return 0;
}

static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
				    struct crypto_cipher *tfm, u8 *ctrblk,
				    unsigned int countersize)
{
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
		   crypto_cipher_alg(tfm)->cia_encrypt;
	unsigned int bsize = crypto_cipher_blocksize(tfm);
	unsigned long alignmask = crypto_cipher_alignmask(tfm);
	unsigned int nbytes = walk->nbytes;
	u8 *src = walk->src.virt.addr;
	u8 ks[bsize + alignmask];
	u8 *keystream = (u8 *)ALIGN((unsigned long)ks, alignmask + 1);

	do {
		/* create keystream */
		fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
		xor_quad(src, keystream, min(nbytes, bsize));

		/* increment counter in counterblock */
		ctr_inc_quad(ctrblk + (bsize - countersize), countersize);

		if (nbytes < bsize)
			break;

		src += bsize;
		nbytes -= bsize;

	} while (nbytes);

	return 0;
}

static int crypto_ctr_crypt(struct blkcipher_desc *desc,
			      struct scatterlist *dst, struct scatterlist *src,
			      unsigned int nbytes)
{
	struct blkcipher_walk walk;
	struct crypto_blkcipher *tfm = desc->tfm;
	struct crypto_ctr_ctx *ctx = crypto_blkcipher_ctx(tfm);
	struct crypto_cipher *child = ctx->child;
	unsigned int bsize = crypto_cipher_blocksize(child);
	struct ctr_instance_ctx *ictx =
		crypto_instance_ctx(crypto_tfm_alg_instance(&tfm->base));
	unsigned long alignmask = crypto_cipher_alignmask(child);
	u8 cblk[bsize + alignmask];
	u8 *counterblk = (u8 *)ALIGN((unsigned long)cblk, alignmask + 1);
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt_block(desc, &walk, bsize);

	/* set up counter block */
	memset(counterblk, 0 , bsize);
	memcpy(counterblk, ctx->nonce, ictx->noncesize);
	memcpy(counterblk + ictx->noncesize, walk.iv, ictx->ivsize);

	/* initialize counter portion of counter block */
	ctr_inc_quad(counterblk + (bsize - ictx->countersize),
		     ictx->countersize);

	while (walk.nbytes) {
		if (walk.src.virt.addr == walk.dst.virt.addr)
			nbytes = crypto_ctr_crypt_inplace(&walk, child,
							  counterblk,
							  ictx->countersize);
		else
			nbytes = crypto_ctr_crypt_segment(&walk, child,
							  counterblk,
							  ictx->countersize);

		err = blkcipher_walk_done(desc, &walk, nbytes);
	}
	return err;
}

static int crypto_ctr_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = (void *)tfm->__crt_alg;
	struct ctr_instance_ctx *ictx = crypto_instance_ctx(inst);
	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_cipher *cipher;

	ctx->nonce = kzalloc(ictx->noncesize, GFP_KERNEL);
	if (!ctx->nonce)
		return -ENOMEM;

	cipher = crypto_spawn_cipher(&ictx->alg);
	if (IS_ERR(cipher))
		return PTR_ERR(cipher);

	ctx->child = cipher;

	return 0;
}

static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm)
{
	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);

	kfree(ctx->nonce);
	crypto_free_cipher(ctx->child);
}

static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb)
{
	struct crypto_instance *inst;
	struct crypto_alg *alg;
	struct ctr_instance_ctx *ictx;
	unsigned int noncesize;
	unsigned int ivsize;
	unsigned int countersize;
	int err;

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

	alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
				  CRYPTO_ALG_TYPE_MASK);
	if (IS_ERR(alg))
		return ERR_PTR(PTR_ERR(alg));

	err = crypto_attr_u32(tb[2], &noncesize);
	if (err)
		goto out_put_alg;

	err = crypto_attr_u32(tb[3], &ivsize);
	if (err)
		goto out_put_alg;

	err = crypto_attr_u32(tb[4], &countersize);
	if (err)
		goto out_put_alg;

	/* verify size of nonce + iv + counter
	 * counter must be >= 4 bytes.
	 */
	err = -EINVAL;
	if (((noncesize + ivsize + countersize) < alg->cra_blocksize) ||
	    ((noncesize + ivsize) > alg->cra_blocksize) ||
	    (countersize > alg->cra_blocksize) || (countersize < 4))
		goto out_put_alg;

	inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
	err = -ENOMEM;
	if (!inst)
		goto out_put_alg;

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
		     "ctr(%s,%u,%u,%u)", alg->cra_name, noncesize,
		     ivsize, countersize) >= CRYPTO_MAX_ALG_NAME) {
		goto err_free_inst;
	}

	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "ctr(%s,%u,%u,%u)", alg->cra_driver_name, noncesize,
		     ivsize, countersize) >= CRYPTO_MAX_ALG_NAME) {
		goto err_free_inst;
	}

	ictx = crypto_instance_ctx(inst);
	ictx->noncesize = noncesize;
	ictx->ivsize = ivsize;
	ictx->countersize = countersize;

	err = crypto_init_spawn(&ictx->alg, alg, inst,
		CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
	if (err)
		goto err_free_inst;

	err = 0;
	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	inst->alg.cra_priority = alg->cra_priority;
	inst->alg.cra_blocksize = 1;
	inst->alg.cra_alignmask = 3;
	inst->alg.cra_type = &crypto_blkcipher_type;

	inst->alg.cra_blkcipher.ivsize = ivsize;
	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize
					      + noncesize;
	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize
					      + noncesize;

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

	inst->alg.cra_init = crypto_ctr_init_tfm;
	inst->alg.cra_exit = crypto_ctr_exit_tfm;

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

err_free_inst:
	if (err)
		kfree(inst);

out_put_alg:
	crypto_mod_put(alg);

	if (err)
		inst = ERR_PTR(err);

	return inst;
}

static void crypto_ctr_free(struct crypto_instance *inst)
{
	struct ctr_instance_ctx *ictx = crypto_instance_ctx(inst);

	crypto_drop_spawn(&ictx->alg);
	kfree(inst);
}

static struct crypto_template crypto_ctr_tmpl = {
	.name = "ctr",
	.alloc = crypto_ctr_alloc,
	.free = crypto_ctr_free,
	.module = THIS_MODULE,
};

static int __init crypto_ctr_module_init(void)
{
	return crypto_register_template(&crypto_ctr_tmpl);
}

static void __exit crypto_ctr_module_exit(void)
{
	crypto_unregister_template(&crypto_ctr_tmpl);
}

module_init(crypto_ctr_module_init);
module_exit(crypto_ctr_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("CTR Counter block mode");
Commit	Line	Data
23e353c8 JL	1	/*
	2	* CTR: Counter mode
	3	*
	4	* (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the Free
	8	* Software Foundation; either version 2 of the License, or (at your option)
	9	* any later version.
	10	*
	11	*/
	12
	13	#include <crypto/algapi.h>
	14	#include <linux/err.h>
	15	#include <linux/init.h>
	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
	18	#include <linux/random.h>
	19	#include <linux/scatterlist.h>
	20	#include <linux/slab.h>
	21
	22	struct ctr_instance_ctx {
	23	struct crypto_spawn alg;
	24	unsigned int noncesize;
	25	unsigned int ivsize;
41fdab3d	26	unsigned int countersize;
23e353c8 JL	27	};
	28
	29	struct crypto_ctr_ctx {
	30	struct crypto_cipher *child;
	31	u8 *nonce;
	32	};
	33
	34	static inline void __ctr_inc_byte(u8 *a, unsigned int size)
	35	{
	36	u8 *b = (a + size);
	37	u8 c;
	38
	39	for (; size; size--) {
	40	c = *--b + 1;
	41	*b = c;
	42	if (c)
	43	break;
	44	}
	45	}
	46
	47	static void ctr_inc_quad(u8 *a, unsigned int size)
	48	{
	49	__be32 b = (__be32 )(a + size);
	50	u32 c;
	51
	52	for (; size >= 4; size -=4) {
	53	c = be32_to_cpu(*--b) + 1;
	54	*b = cpu_to_be32(c);
	55	if (c)
	56	return;
	57	}
	58
	59	__ctr_inc_byte(a, size);
	60	}
	61
	62	static void xor_byte(u8 a, const u8 b, unsigned int bs)
	63	{
	64	for (; bs; bs--)
	65	a++ ^= b++;
	66	}
	67
	68	static void xor_quad(u8 dst, const u8 src, unsigned int bs)
	69	{
	70	u32 a = (u32 )dst;
	71	u32 b = (u32 )src;
	72
	73	for (; bs >= 4; bs -= 4)
	74	a++ ^= b++;
	75
	76	xor_byte((u8 )a, (u8 )b, bs);
	77	}
	78
	79	static int crypto_ctr_setkey(struct crypto_tfm parent, const u8 key,
	80	unsigned int keylen)
	81	{
	82	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(parent);
	83	struct crypto_cipher *child = ctx->child;
	84	struct ctr_instance_ctx *ictx =
	85	crypto_instance_ctx(crypto_tfm_alg_instance(parent));
	86	unsigned int noncelen = ictx->noncesize;
	87	int err = 0;
	88
	89	/* the nonce is stored in bytes at end of key */
	90	if (keylen < noncelen)
91	return -EINVAL;
92
93	memcpy(ctx->nonce, key + (keylen - noncelen), noncelen);
94
95	keylen -= noncelen;
96
97	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
98	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
99	CRYPTO_TFM_REQ_MASK);
100	err = crypto_cipher_setkey(child, key, keylen);
101	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
102	CRYPTO_TFM_RES_MASK);
103
104	return err;
105	}
106
107	static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
108	struct crypto_cipher tfm, u8 ctrblk,
109	unsigned int countersize)
110	{
111	void (fn)(struct crypto_tfm , u8 , const u8 ) =
112	crypto_cipher_alg(tfm)->cia_encrypt;
113	unsigned int bsize = crypto_cipher_blocksize(tfm);
114	unsigned long alignmask = crypto_cipher_alignmask(tfm);
115	u8 ks[bsize + alignmask];
116	u8 keystream = (u8 )ALIGN((unsigned long)ks, alignmask + 1);
117	u8 *src = walk->src.virt.addr;
118	u8 *dst = walk->dst.virt.addr;
119	unsigned int nbytes = walk->nbytes;
120
121	do {
122	/* create keystream */
123	fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
124	xor_quad(keystream, src, min(nbytes, bsize));
125
126	/* copy result into dst */
127	memcpy(dst, keystream, min(nbytes, bsize));
128
129	/* increment counter in counterblock */
130	ctr_inc_quad(ctrblk + (bsize - countersize), countersize);
131
132	if (nbytes < bsize)
133	break;
134
135	src += bsize;
136	dst += bsize;
137	nbytes -= bsize;
138
139	} while (nbytes);
140
141	return 0;
142	}
143
144	static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
145	struct crypto_cipher tfm, u8 ctrblk,
146	unsigned int countersize)
147	{
148	void (fn)(struct crypto_tfm , u8 , const u8 ) =
149	crypto_cipher_alg(tfm)->cia_encrypt;
150	unsigned int bsize = crypto_cipher_blocksize(tfm);
151	unsigned long alignmask = crypto_cipher_alignmask(tfm);
152	unsigned int nbytes = walk->nbytes;
153	u8 *src = walk->src.virt.addr;
154	u8 ks[bsize + alignmask];
155	u8 keystream = (u8 )ALIGN((unsigned long)ks, alignmask + 1);
156
157	do {
158	/* create keystream */
159	fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
160	xor_quad(src, keystream, min(nbytes, bsize));
161
162	/* increment counter in counterblock */
163	ctr_inc_quad(ctrblk + (bsize - countersize), countersize);
164
165	if (nbytes < bsize)
166	break;
167
168	src += bsize;
169	nbytes -= bsize;
170
171	} while (nbytes);
172
173	return 0;
174	}
175
176	static int crypto_ctr_crypt(struct blkcipher_desc *desc,
177	struct scatterlist dst, struct scatterlist src,
178	unsigned int nbytes)
179	{
180	struct blkcipher_walk walk;
181	struct crypto_blkcipher *tfm = desc->tfm;
182	struct crypto_ctr_ctx *ctx = crypto_blkcipher_ctx(tfm);
183	struct crypto_cipher *child = ctx->child;
184	unsigned int bsize = crypto_cipher_blocksize(child);
185	struct ctr_instance_ctx *ictx =
186	crypto_instance_ctx(crypto_tfm_alg_instance(&tfm->base));
187	unsigned long alignmask = crypto_cipher_alignmask(child);
188	u8 cblk[bsize + alignmask];
189	u8 counterblk = (u8 )ALIGN((unsigned long)cblk, alignmask + 1);
23e353c8 JL	190	int err;
	191
	192	blkcipher_walk_init(&walk, dst, src, nbytes);
	193	err = blkcipher_walk_virt_block(desc, &walk, bsize);
	194
	195	/* set up counter block */
	196	memset(counterblk, 0 , bsize);
	197	memcpy(counterblk, ctx->nonce, ictx->noncesize);
	198	memcpy(counterblk + ictx->noncesize, walk.iv, ictx->ivsize);
	199
	200	/* initialize counter portion of counter block */
41fdab3d JL	201	ctr_inc_quad(counterblk + (bsize - ictx->countersize),
41fdab3d JL	202	ictx->countersize);
23e353c8 JL	203
	204	while (walk.nbytes) {
	205	if (walk.src.virt.addr == walk.dst.virt.addr)
	206	nbytes = crypto_ctr_crypt_inplace(&walk, child,
	207	counterblk,
41fdab3d	208	ictx->countersize);
23e353c8 JL	209	else
	210	nbytes = crypto_ctr_crypt_segment(&walk, child,
	211	counterblk,
41fdab3d	212	ictx->countersize);
23e353c8 JL	213
	214	err = blkcipher_walk_done(desc, &walk, nbytes);
	215	}
	216	return err;
	217	}
	218
	219	static int crypto_ctr_init_tfm(struct crypto_tfm *tfm)
	220	{
	221	struct crypto_instance inst = (void )tfm->__crt_alg;
	222	struct ctr_instance_ctx *ictx = crypto_instance_ctx(inst);
	223	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
	224	struct crypto_cipher *cipher;
	225
	226	ctx->nonce = kzalloc(ictx->noncesize, GFP_KERNEL);
	227	if (!ctx->nonce)
	228	return -ENOMEM;
	229
	230	cipher = crypto_spawn_cipher(&ictx->alg);
	231	if (IS_ERR(cipher))
	232	return PTR_ERR(cipher);
	233
	234	ctx->child = cipher;
	235
	236	return 0;
	237	}
	238
	239	static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm)
	240	{
	241	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
	242
	243	kfree(ctx->nonce);
	244	crypto_free_cipher(ctx->child);
	245	}
	246
	247	static struct crypto_instance crypto_ctr_alloc(struct rtattr *tb)
	248	{
	249	struct crypto_instance *inst;
	250	struct crypto_alg *alg;
	251	struct ctr_instance_ctx *ictx;
	252	unsigned int noncesize;
	253	unsigned int ivsize;
41fdab3d	254	unsigned int countersize;
23e353c8 JL	255	int err;
	256
	257	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
	258	if (err)
	259	return ERR_PTR(err);
	260
	261	alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
	262	CRYPTO_ALG_TYPE_MASK);
	263	if (IS_ERR(alg))
	264	return ERR_PTR(PTR_ERR(alg));
	265
	266	err = crypto_attr_u32(tb[2], &noncesize);
	267	if (err)
	268	goto out_put_alg;
	269
	270	err = crypto_attr_u32(tb[3], &ivsize);
	271	if (err)
	272	goto out_put_alg;
	273
41fdab3d JL	274	err = crypto_attr_u32(tb[4], &countersize);
	275	if (err)
	276	goto out_put_alg;
	277
	278	/* verify size of nonce + iv + counter
	279	* counter must be >= 4 bytes.
	280	*/
23e353c8	281	err = -EINVAL;
41fdab3d JL	282	if (((noncesize + ivsize + countersize) < alg->cra_blocksize) \|\|
	283	((noncesize + ivsize) > alg->cra_blocksize) \|\|
	284	(countersize > alg->cra_blocksize) \|\| (countersize < 4))
23e353c8 JL	285	goto out_put_alg;
	286
	287	inst = kzalloc(sizeof(inst) + sizeof(ictx), GFP_KERNEL);
	288	err = -ENOMEM;
	289	if (!inst)
	290	goto out_put_alg;
	291
	292	err = -ENAMETOOLONG;
	293	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
41fdab3d JL	294	"ctr(%s,%u,%u,%u)", alg->cra_name, noncesize,
41fdab3d JL	295	ivsize, countersize) >= CRYPTO_MAX_ALG_NAME) {
23e353c8 JL	296	goto err_free_inst;
	297	}
	298
	299	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
41fdab3d JL	300	"ctr(%s,%u,%u,%u)", alg->cra_driver_name, noncesize,
41fdab3d JL	301	ivsize, countersize) >= CRYPTO_MAX_ALG_NAME) {
23e353c8 JL	302	goto err_free_inst;
	303	}
	304
	305	ictx = crypto_instance_ctx(inst);
	306	ictx->noncesize = noncesize;
	307	ictx->ivsize = ivsize;
41fdab3d	308	ictx->countersize = countersize;
23e353c8 JL	309
	310	err = crypto_init_spawn(&ictx->alg, alg, inst,
	311	CRYPTO_ALG_TYPE_MASK \| CRYPTO_ALG_ASYNC);
	312	if (err)
	313	goto err_free_inst;
	314
	315	err = 0;
	316	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	317	inst->alg.cra_priority = alg->cra_priority;
	318	inst->alg.cra_blocksize = 1;
	319	inst->alg.cra_alignmask = 3;
	320	inst->alg.cra_type = &crypto_blkcipher_type;
	321
	322	inst->alg.cra_blkcipher.ivsize = ivsize;
	323	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize
	324	+ noncesize;
	325	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize
	326	+ noncesize;
	327
	328	inst->alg.cra_ctxsize = sizeof(struct crypto_ctr_ctx);
	329
	330	inst->alg.cra_init = crypto_ctr_init_tfm;
	331	inst->alg.cra_exit = crypto_ctr_exit_tfm;
	332
	333	inst->alg.cra_blkcipher.setkey = crypto_ctr_setkey;
	334	inst->alg.cra_blkcipher.encrypt = crypto_ctr_crypt;
	335	inst->alg.cra_blkcipher.decrypt = crypto_ctr_crypt;
	336
	337	err_free_inst:
	338	if (err)
	339	kfree(inst);
	340
	341	out_put_alg:
	342	crypto_mod_put(alg);
	343
	344	if (err)
	345	inst = ERR_PTR(err);
	346
	347	return inst;
	348	}
	349
	350	static void crypto_ctr_free(struct crypto_instance *inst)
	351	{
	352	struct ctr_instance_ctx *ictx = crypto_instance_ctx(inst);
	353
	354	crypto_drop_spawn(&ictx->alg);
	355	kfree(inst);
	356	}
	357
	358	static struct crypto_template crypto_ctr_tmpl = {
	359	.name = "ctr",
	360	.alloc = crypto_ctr_alloc,
	361	.free = crypto_ctr_free,
	362	.module = THIS_MODULE,
	363	};
	364
	365	static int __init crypto_ctr_module_init(void)
	366	{
	367	return crypto_register_template(&crypto_ctr_tmpl);
	368	}
	369
	370	static void __exit crypto_ctr_module_exit(void)
	371	{
	372	crypto_unregister_template(&crypto_ctr_tmpl);
373	}
374
375	module_init(crypto_ctr_module_init);
376	module_exit(crypto_ctr_module_exit);
377
378	MODULE_LICENSE("GPL");
379	MODULE_DESCRIPTION("CTR Counter block mode");