[linux.git] / crypto / ctr.c

/*
 * CTR: Counter mode
 *
 * (C) Copyright IBM Corp. 2007 - Joy Latten <[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 <crypto/ctr.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 crypto_ctr_ctx {
	struct crypto_cipher *child;
};

struct crypto_rfc3686_ctx {
	struct crypto_blkcipher *child;
	u8 nonce[CTR_RFC3686_NONCE_SIZE];
};

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;
	int err;

	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 void crypto_ctr_crypt_final(struct blkcipher_walk *walk,
				   struct crypto_cipher *tfm)
{
	unsigned int bsize = crypto_cipher_blocksize(tfm);
	unsigned long alignmask = crypto_cipher_alignmask(tfm);
	u8 *ctrblk = walk->iv;
	u8 tmp[bsize + alignmask];
	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
	u8 *src = walk->src.virt.addr;
	u8 *dst = walk->dst.virt.addr;
	unsigned int nbytes = walk->nbytes;

	crypto_cipher_encrypt_one(tfm, keystream, ctrblk);
	crypto_xor(keystream, src, nbytes);
	memcpy(dst, keystream, nbytes);

	crypto_inc(ctrblk, bsize);
}

static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
				    struct crypto_cipher *tfm)
{
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
		   crypto_cipher_alg(tfm)->cia_encrypt;
	unsigned int bsize = crypto_cipher_blocksize(tfm);
	u8 *ctrblk = walk->iv;
	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), dst, ctrblk);
		crypto_xor(dst, src, bsize);

		/* increment counter in counterblock */
		crypto_inc(ctrblk, bsize);

		src += bsize;
		dst += bsize;
	} while ((nbytes -= bsize) >= bsize);

	return nbytes;
}

static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
				    struct crypto_cipher *tfm)
{
	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 *ctrblk = walk->iv;
	u8 *src = walk->src.virt.addr;
	u8 tmp[bsize + alignmask];
	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);

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

		/* increment counter in counterblock */
		crypto_inc(ctrblk, bsize);

		src += bsize;
	} while ((nbytes -= bsize) >= bsize);

	return nbytes;
}

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);
	int err;

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

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

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

	if (walk.nbytes) {
		crypto_ctr_crypt_final(&walk, child);
		err = blkcipher_walk_done(desc, &walk, 0);
	}

	return err;
}

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

	cipher = crypto_spawn_cipher(spawn);
	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);

	crypto_free_cipher(ctx->child);
}

static struct crypto_instance *crypto_ctr_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_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
				  CRYPTO_ALG_TYPE_MASK);
	if (IS_ERR(alg))
		return ERR_PTR(PTR_ERR(alg));

	/* Block size must be >= 4 bytes. */
	err = -EINVAL;
	if (alg->cra_blocksize < 4)
		goto out_put_alg;

	/* If this is false we'd fail the alignment of crypto_inc. */
	if (alg->cra_blocksize % 4)
		goto out_put_alg;

	inst = crypto_alloc_instance("ctr", alg);
	if (IS_ERR(inst))
		goto out;

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	inst->alg.cra_priority = alg->cra_priority;
	inst->alg.cra_blocksize = 1;
	inst->alg.cra_alignmask = alg->cra_alignmask | (__alignof__(u32) - 1);
	inst->alg.cra_type = &crypto_blkcipher_type;

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

	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;

out:
	crypto_mod_put(alg);
	return inst;

out_put_alg:
	inst = ERR_PTR(err);
	goto out;
}

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

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

static int crypto_rfc3686_setkey(struct crypto_tfm *parent, const u8 *key,
				 unsigned int keylen)
{
	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(parent);
	struct crypto_blkcipher *child = ctx->child;
	int err;

	/* the nonce is stored in bytes at end of key */
	if (keylen < CTR_RFC3686_NONCE_SIZE)
		return -EINVAL;

	memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
	       CTR_RFC3686_NONCE_SIZE);

	keylen -= CTR_RFC3686_NONCE_SIZE;

	crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_blkcipher_set_flags(child, crypto_tfm_get_flags(parent) &
					  CRYPTO_TFM_REQ_MASK);
	err = crypto_blkcipher_setkey(child, key, keylen);
	crypto_tfm_set_flags(parent, crypto_blkcipher_get_flags(child) &
				     CRYPTO_TFM_RES_MASK);

	return err;
}

static int crypto_rfc3686_crypt(struct blkcipher_desc *desc,
				struct scatterlist *dst,
				struct scatterlist *src, unsigned int nbytes)
{
	struct crypto_blkcipher *tfm = desc->tfm;
	struct crypto_rfc3686_ctx *ctx = crypto_blkcipher_ctx(tfm);
	struct crypto_blkcipher *child = ctx->child;
	unsigned long alignmask = crypto_blkcipher_alignmask(tfm);
	u8 ivblk[CTR_RFC3686_BLOCK_SIZE + alignmask];
	u8 *iv = PTR_ALIGN(ivblk + 0, alignmask + 1);
	u8 *info = desc->info;
	int err;

	/* set up counter block */
	memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
	memcpy(iv + CTR_RFC3686_NONCE_SIZE, info, CTR_RFC3686_IV_SIZE);

	/* initialize counter portion of counter block */
	*(__be32 *)(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
		cpu_to_be32(1);

	desc->tfm = child;
	desc->info = iv;
	err = crypto_blkcipher_encrypt_iv(desc, dst, src, nbytes);
	desc->tfm = tfm;
	desc->info = info;

	return err;
}

static int crypto_rfc3686_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = (void *)tfm->__crt_alg;
	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_blkcipher *cipher;

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

	ctx->child = cipher;

	return 0;
}

static void crypto_rfc3686_exit_tfm(struct crypto_tfm *tfm)
{
	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);

	crypto_free_blkcipher(ctx->child);
}

static struct crypto_instance *crypto_rfc3686_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_attr_alg(tb[1], CRYPTO_ALG_TYPE_BLKCIPHER,
				  CRYPTO_ALG_TYPE_MASK);
	err = PTR_ERR(alg);
	if (IS_ERR(alg))
		return ERR_PTR(err);

	/* We only support 16-byte blocks. */
	err = -EINVAL;
	if (alg->cra_blkcipher.ivsize != CTR_RFC3686_BLOCK_SIZE)
		goto out_put_alg;

	/* Not a stream cipher? */
	if (alg->cra_blocksize != 1)
		goto out_put_alg;

	inst = crypto_alloc_instance("rfc3686", alg);
	if (IS_ERR(inst))
		goto out;

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

	inst->alg.cra_blkcipher.ivsize = CTR_RFC3686_IV_SIZE;
	inst->alg.cra_blkcipher.min_keysize = alg->cra_blkcipher.min_keysize
					      + CTR_RFC3686_NONCE_SIZE;
	inst->alg.cra_blkcipher.max_keysize = alg->cra_blkcipher.max_keysize
					      + CTR_RFC3686_NONCE_SIZE;

	inst->alg.cra_blkcipher.geniv = "seqiv";

	inst->alg.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);

	inst->alg.cra_init = crypto_rfc3686_init_tfm;
	inst->alg.cra_exit = crypto_rfc3686_exit_tfm;

	inst->alg.cra_blkcipher.setkey = crypto_rfc3686_setkey;
	inst->alg.cra_blkcipher.encrypt = crypto_rfc3686_crypt;
	inst->alg.cra_blkcipher.decrypt = crypto_rfc3686_crypt;

out:
	crypto_mod_put(alg);
	return inst;

out_put_alg:
	inst = ERR_PTR(err);
	goto out;
}

static struct crypto_template crypto_rfc3686_tmpl = {
	.name = "rfc3686",
	.alloc = crypto_rfc3686_alloc,
	.free = crypto_ctr_free,
	.module = THIS_MODULE,
};

static int __init crypto_ctr_module_init(void)
{
	int err;

	err = crypto_register_template(&crypto_ctr_tmpl);
	if (err)
		goto out;

	err = crypto_register_template(&crypto_rfc3686_tmpl);
	if (err)
		goto out_drop_ctr;

out:
	return err;

out_drop_ctr:
	crypto_unregister_template(&crypto_ctr_tmpl);
	goto out;
}

static void __exit crypto_ctr_module_exit(void)
{
	crypto_unregister_template(&crypto_rfc3686_tmpl);
	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");
MODULE_ALIAS("rfc3686");
Commit	Line	Data
23e353c8 JL	1	/*
	2	* CTR: Counter mode
	3	*
	4	* (C) Copyright IBM Corp. 2007 - Joy Latten <[email protected]>
	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>
5311f248	14	#include <crypto/ctr.h>
23e353c8 JL	15	#include <linux/err.h>
	16	#include <linux/init.h>
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/random.h>
	20	#include <linux/scatterlist.h>
	21	#include <linux/slab.h>
	22
23e353c8 JL	23	struct crypto_ctr_ctx {
23e353c8 JL	24	struct crypto_cipher *child;
5311f248 HX	25	};
	26
	27	struct crypto_rfc3686_ctx {
	28	struct crypto_blkcipher *child;
	29	u8 nonce[CTR_RFC3686_NONCE_SIZE];
23e353c8 JL	30	};
23e353c8 JL	31
23e353c8 JL	32	static int crypto_ctr_setkey(struct crypto_tfm parent, const u8 key,
	33	unsigned int keylen)
	34	{
	35	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(parent);
	36	struct crypto_cipher *child = ctx->child;
5311f248	37	int err;
23e353c8 JL	38
	39	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	40	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
	41	CRYPTO_TFM_REQ_MASK);
	42	err = crypto_cipher_setkey(child, key, keylen);
	43	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
	44	CRYPTO_TFM_RES_MASK);
	45
	46	return err;
	47	}
	48
0971eb0d	49	static void crypto_ctr_crypt_final(struct blkcipher_walk *walk,
5311f248	50	struct crypto_cipher *tfm)
0971eb0d HX	51	{
0971eb0d HX	52	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248 HX	53	unsigned long alignmask = crypto_cipher_alignmask(tfm);
	54	u8 *ctrblk = walk->iv;
	55	u8 tmp[bsize + alignmask];
	56	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
0971eb0d HX	57	u8 *src = walk->src.virt.addr;
	58	u8 *dst = walk->dst.virt.addr;
	59	unsigned int nbytes = walk->nbytes;
	60
	61	crypto_cipher_encrypt_one(tfm, keystream, ctrblk);
	62	crypto_xor(keystream, src, nbytes);
	63	memcpy(dst, keystream, nbytes);
5311f248 HX	64
5311f248 HX	65	crypto_inc(ctrblk, bsize);
0971eb0d HX	66	}
0971eb0d HX	67
23e353c8	68	static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
5311f248	69	struct crypto_cipher *tfm)
23e353c8 JL	70	{
	71	void (fn)(struct crypto_tfm , u8 , const u8 ) =
	72	crypto_cipher_alg(tfm)->cia_encrypt;
	73	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248	74	u8 *ctrblk = walk->iv;
23e353c8 JL	75	u8 *src = walk->src.virt.addr;
	76	u8 *dst = walk->dst.virt.addr;
	77	unsigned int nbytes = walk->nbytes;
	78
	79	do {
	80	/* create keystream */
0971eb0d HX	81	fn(crypto_cipher_tfm(tfm), dst, ctrblk);
0971eb0d HX	82	crypto_xor(dst, src, bsize);
23e353c8 JL	83
23e353c8 JL	84	/* increment counter in counterblock */
5311f248	85	crypto_inc(ctrblk, bsize);
23e353c8	86
23e353c8 JL	87	src += bsize;
23e353c8 JL	88	dst += bsize;
0971eb0d	89	} while ((nbytes -= bsize) >= bsize);
23e353c8	90
0971eb0d	91	return nbytes;
23e353c8 JL	92	}
	93
	94	static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
5311f248	95	struct crypto_cipher *tfm)
23e353c8 JL	96	{
	97	void (fn)(struct crypto_tfm , u8 , const u8 ) =
	98	crypto_cipher_alg(tfm)->cia_encrypt;
	99	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248	100	unsigned long alignmask = crypto_cipher_alignmask(tfm);
23e353c8	101	unsigned int nbytes = walk->nbytes;
5311f248	102	u8 *ctrblk = walk->iv;
23e353c8	103	u8 *src = walk->src.virt.addr;
5311f248 HX	104	u8 tmp[bsize + alignmask];
5311f248 HX	105	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
23e353c8 JL	106
	107	do {
	108	/* create keystream */
	109	fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
0971eb0d	110	crypto_xor(src, keystream, bsize);
23e353c8 JL	111
23e353c8 JL	112	/* increment counter in counterblock */
5311f248	113	crypto_inc(ctrblk, bsize);
23e353c8	114
23e353c8	115	src += bsize;
0971eb0d	116	} while ((nbytes -= bsize) >= bsize);
23e353c8	117
0971eb0d	118	return nbytes;
23e353c8 JL	119	}
	120
	121	static int crypto_ctr_crypt(struct blkcipher_desc *desc,
	122	struct scatterlist dst, struct scatterlist src,
	123	unsigned int nbytes)
	124	{
	125	struct blkcipher_walk walk;
	126	struct crypto_blkcipher *tfm = desc->tfm;
	127	struct crypto_ctr_ctx *ctx = crypto_blkcipher_ctx(tfm);
	128	struct crypto_cipher *child = ctx->child;
	129	unsigned int bsize = crypto_cipher_blocksize(child);
23e353c8 JL	130	int err;
	131
	132	blkcipher_walk_init(&walk, dst, src, nbytes);
	133	err = blkcipher_walk_virt_block(desc, &walk, bsize);
	134
0971eb0d	135	while (walk.nbytes >= bsize) {
23e353c8	136	if (walk.src.virt.addr == walk.dst.virt.addr)
5311f248	137	nbytes = crypto_ctr_crypt_inplace(&walk, child);
23e353c8	138	else
5311f248	139	nbytes = crypto_ctr_crypt_segment(&walk, child);
23e353c8 JL	140
	141	err = blkcipher_walk_done(desc, &walk, nbytes);
	142	}
0971eb0d HX	143
0971eb0d HX	144	if (walk.nbytes) {
5311f248	145	crypto_ctr_crypt_final(&walk, child);
0971eb0d HX	146	err = blkcipher_walk_done(desc, &walk, 0);
	147	}
	148
23e353c8 JL	149	return err;
	150	}
	151
	152	static int crypto_ctr_init_tfm(struct crypto_tfm *tfm)
	153	{
	154	struct crypto_instance inst = (void )tfm->__crt_alg;
5311f248	155	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
23e353c8 JL	156	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
	157	struct crypto_cipher *cipher;
	158
5311f248	159	cipher = crypto_spawn_cipher(spawn);
23e353c8 JL	160	if (IS_ERR(cipher))
	161	return PTR_ERR(cipher);
	162
	163	ctx->child = cipher;
	164
	165	return 0;
	166	}
	167
	168	static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm)
	169	{
	170	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
	171
23e353c8 JL	172	crypto_free_cipher(ctx->child);
	173	}
	174
	175	static struct crypto_instance crypto_ctr_alloc(struct rtattr *tb)
	176	{
	177	struct crypto_instance *inst;
	178	struct crypto_alg *alg;
23e353c8 JL	179	int err;
	180
	181	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
	182	if (err)
	183	return ERR_PTR(err);
	184
	185	alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
	186	CRYPTO_ALG_TYPE_MASK);
	187	if (IS_ERR(alg))
	188	return ERR_PTR(PTR_ERR(alg));
	189
5311f248	190	/* Block size must be >= 4 bytes. */
23e353c8	191	err = -EINVAL;
5311f248	192	if (alg->cra_blocksize < 4)
23e353c8 JL	193	goto out_put_alg;
23e353c8 JL	194
3f8214ea	195	/* If this is false we'd fail the alignment of crypto_inc. */
5311f248	196	if (alg->cra_blocksize % 4)
3f8214ea HX	197	goto out_put_alg;
3f8214ea HX	198
5311f248 HX	199	inst = crypto_alloc_instance("ctr", alg);
	200	if (IS_ERR(inst))
	201	goto out;
23e353c8	202
23e353c8 JL	203	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	204	inst->alg.cra_priority = alg->cra_priority;
	205	inst->alg.cra_blocksize = 1;
0971eb0d	206	inst->alg.cra_alignmask = alg->cra_alignmask \| (__alignof__(u32) - 1);
23e353c8 JL	207	inst->alg.cra_type = &crypto_blkcipher_type;
23e353c8 JL	208
5311f248 HX	209	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
	210	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
	211	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
23e353c8 JL	212
	213	inst->alg.cra_ctxsize = sizeof(struct crypto_ctr_ctx);
	214
	215	inst->alg.cra_init = crypto_ctr_init_tfm;
	216	inst->alg.cra_exit = crypto_ctr_exit_tfm;
	217
	218	inst->alg.cra_blkcipher.setkey = crypto_ctr_setkey;
	219	inst->alg.cra_blkcipher.encrypt = crypto_ctr_crypt;
	220	inst->alg.cra_blkcipher.decrypt = crypto_ctr_crypt;
	221
5311f248	222	out:
23e353c8	223	crypto_mod_put(alg);
23e353c8	224	return inst;
5311f248 HX	225
	226	out_put_alg:
	227	inst = ERR_PTR(err);
	228	goto out;
23e353c8 JL	229	}
	230
	231	static void crypto_ctr_free(struct crypto_instance *inst)
	232	{
5311f248	233	crypto_drop_spawn(crypto_instance_ctx(inst));
23e353c8 JL	234	kfree(inst);
	235	}
	236
	237	static struct crypto_template crypto_ctr_tmpl = {
	238	.name = "ctr",
	239	.alloc = crypto_ctr_alloc,
	240	.free = crypto_ctr_free,
	241	.module = THIS_MODULE,
	242	};
	243
5311f248 HX	244	static int crypto_rfc3686_setkey(struct crypto_tfm parent, const u8 key,
	245	unsigned int keylen)
	246	{
	247	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(parent);
	248	struct crypto_blkcipher *child = ctx->child;
	249	int err;
	250
	251	/* the nonce is stored in bytes at end of key */
	252	if (keylen < CTR_RFC3686_NONCE_SIZE)
	253	return -EINVAL;
	254
	255	memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
	256	CTR_RFC3686_NONCE_SIZE);
	257
	258	keylen -= CTR_RFC3686_NONCE_SIZE;
	259
	260	crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	261	crypto_blkcipher_set_flags(child, crypto_tfm_get_flags(parent) &
	262	CRYPTO_TFM_REQ_MASK);
	263	err = crypto_blkcipher_setkey(child, key, keylen);
	264	crypto_tfm_set_flags(parent, crypto_blkcipher_get_flags(child) &
	265	CRYPTO_TFM_RES_MASK);
	266
	267	return err;
	268	}
	269
	270	static int crypto_rfc3686_crypt(struct blkcipher_desc *desc,
	271	struct scatterlist *dst,
	272	struct scatterlist *src, unsigned int nbytes)
	273	{
	274	struct crypto_blkcipher *tfm = desc->tfm;
	275	struct crypto_rfc3686_ctx *ctx = crypto_blkcipher_ctx(tfm);
	276	struct crypto_blkcipher *child = ctx->child;
	277	unsigned long alignmask = crypto_blkcipher_alignmask(tfm);
	278	u8 ivblk[CTR_RFC3686_BLOCK_SIZE + alignmask];
	279	u8 *iv = PTR_ALIGN(ivblk + 0, alignmask + 1);
	280	u8 *info = desc->info;
	281	int err;
	282
	283	/* set up counter block */
	284	memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
	285	memcpy(iv + CTR_RFC3686_NONCE_SIZE, info, CTR_RFC3686_IV_SIZE);
	286
	287	/* initialize counter portion of counter block */
	288	(__be32 )(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
	289	cpu_to_be32(1);
	290
	291	desc->tfm = child;
	292	desc->info = iv;
	293	err = crypto_blkcipher_encrypt_iv(desc, dst, src, nbytes);
	294	desc->tfm = tfm;
	295	desc->info = info;
	296
	297	return err;
	298	}
	299
	300	static int crypto_rfc3686_init_tfm(struct crypto_tfm *tfm)
	301	{
	302	struct crypto_instance inst = (void )tfm->__crt_alg;
	303	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	304	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);
	305	struct crypto_blkcipher *cipher;
	306
	307	cipher = crypto_spawn_blkcipher(spawn);
308	if (IS_ERR(cipher))
309	return PTR_ERR(cipher);
310
311	ctx->child = cipher;
312
313	return 0;
314	}
315
316	static void crypto_rfc3686_exit_tfm(struct crypto_tfm *tfm)
317	{
318	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);
319
320	crypto_free_blkcipher(ctx->child);
321	}
322
323	static struct crypto_instance crypto_rfc3686_alloc(struct rtattr *tb)
324	{
325	struct crypto_instance *inst;
326	struct crypto_alg *alg;
327	int err;
328
329	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
330	if (err)
331	return ERR_PTR(err);
332
333	alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_BLKCIPHER,
334	CRYPTO_ALG_TYPE_MASK);
335	err = PTR_ERR(alg);
336	if (IS_ERR(alg))
337	return ERR_PTR(err);
338
339	/* We only support 16-byte blocks. */
340	err = -EINVAL;
341	if (alg->cra_blkcipher.ivsize != CTR_RFC3686_BLOCK_SIZE)
342	goto out_put_alg;
343
344	/* Not a stream cipher? */
345	if (alg->cra_blocksize != 1)
346	goto out_put_alg;
347
348	inst = crypto_alloc_instance("rfc3686", alg);
349	if (IS_ERR(inst))
350	goto out;
351
352	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
353	inst->alg.cra_priority = alg->cra_priority;
354	inst->alg.cra_blocksize = 1;
355	inst->alg.cra_alignmask = alg->cra_alignmask;
356	inst->alg.cra_type = &crypto_blkcipher_type;
357
358	inst->alg.cra_blkcipher.ivsize = CTR_RFC3686_IV_SIZE;
359	inst->alg.cra_blkcipher.min_keysize = alg->cra_blkcipher.min_keysize
360	+ CTR_RFC3686_NONCE_SIZE;
361	inst->alg.cra_blkcipher.max_keysize = alg->cra_blkcipher.max_keysize
362	+ CTR_RFC3686_NONCE_SIZE;
363
0a270321 HX	364	inst->alg.cra_blkcipher.geniv = "seqiv";
0a270321 HX	365
5311f248 HX	366	inst->alg.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
	367
	368	inst->alg.cra_init = crypto_rfc3686_init_tfm;
	369	inst->alg.cra_exit = crypto_rfc3686_exit_tfm;
	370
	371	inst->alg.cra_blkcipher.setkey = crypto_rfc3686_setkey;
	372	inst->alg.cra_blkcipher.encrypt = crypto_rfc3686_crypt;
	373	inst->alg.cra_blkcipher.decrypt = crypto_rfc3686_crypt;
	374
	375	out:
	376	crypto_mod_put(alg);
	377	return inst;
	378
	379	out_put_alg:
	380	inst = ERR_PTR(err);
	381	goto out;
	382	}
	383
	384	static struct crypto_template crypto_rfc3686_tmpl = {
	385	.name = "rfc3686",
	386	.alloc = crypto_rfc3686_alloc,
	387	.free = crypto_ctr_free,
	388	.module = THIS_MODULE,
	389	};
	390
23e353c8 JL	391	static int __init crypto_ctr_module_init(void)
23e353c8 JL	392	{
5311f248 HX	393	int err;
	394
	395	err = crypto_register_template(&crypto_ctr_tmpl);
	396	if (err)
	397	goto out;
	398
	399	err = crypto_register_template(&crypto_rfc3686_tmpl);
	400	if (err)
	401	goto out_drop_ctr;
	402
	403	out:
	404	return err;
	405
	406	out_drop_ctr:
	407	crypto_unregister_template(&crypto_ctr_tmpl);
	408	goto out;
23e353c8 JL	409	}
	410
	411	static void __exit crypto_ctr_module_exit(void)
	412	{
5311f248	413	crypto_unregister_template(&crypto_rfc3686_tmpl);
23e353c8 JL	414	crypto_unregister_template(&crypto_ctr_tmpl);
	415	}
	416
	417	module_init(crypto_ctr_module_init);
	418	module_exit(crypto_ctr_module_exit);
	419
	420	MODULE_LICENSE("GPL");
	421	MODULE_DESCRIPTION("CTR Counter block mode");
5311f248	422	MODULE_ALIAS("rfc3686");