[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 <crypto/internal/skcipher.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_skcipher *child;
	u8 nonce[CTR_RFC3686_NONCE_SIZE];
};

struct crypto_rfc3686_req_ctx {
	u8 iv[CTR_RFC3686_BLOCK_SIZE];
	struct skcipher_request subreq CRYPTO_MINALIGN_ATTR;
};

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[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_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_cpy(dst, keystream, src, 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[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_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_attr_type *algt;
	struct crypto_alg *alg;
	u32 mask;
	int err;

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

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return ERR_CAST(algt);

	mask = CRYPTO_ALG_TYPE_MASK |
		crypto_requires_off(algt->type, algt->mask,
				    CRYPTO_ALG_NEED_FALLBACK);

	alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER, mask);
	if (IS_ERR(alg))
		return ERR_CAST(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;
	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;

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

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_skcipher *parent,
				 const u8 *key, unsigned int keylen)
{
	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
	struct crypto_skcipher *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_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
					 CRYPTO_TFM_REQ_MASK);
	err = crypto_skcipher_setkey(child, key, keylen);
	crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
					  CRYPTO_TFM_RES_MASK);

	return err;
}

static int crypto_rfc3686_crypt(struct skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct crypto_skcipher *child = ctx->child;
	unsigned long align = crypto_skcipher_alignmask(tfm);
	struct crypto_rfc3686_req_ctx *rctx =
		(void *)PTR_ALIGN((u8 *)skcipher_request_ctx(req), align + 1);
	struct skcipher_request *subreq = &rctx->subreq;
	u8 *iv = rctx->iv;

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

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

	skcipher_request_set_tfm(subreq, child);
	skcipher_request_set_callback(subreq, req->base.flags,
				      req->base.complete, req->base.data);
	skcipher_request_set_crypt(subreq, req->src, req->dst,
				   req->cryptlen, iv);

	return crypto_skcipher_encrypt(subreq);
}

static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm)
{
	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct crypto_skcipher *cipher;
	unsigned long align;
	unsigned int reqsize;

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

	ctx->child = cipher;

	align = crypto_skcipher_alignmask(tfm);
	align &= ~(crypto_tfm_ctx_alignment() - 1);
	reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) +
		  crypto_skcipher_reqsize(cipher);
	crypto_skcipher_set_reqsize(tfm, reqsize);

	return 0;
}

static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm)
{
	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);

	crypto_free_skcipher(ctx->child);
}

static void crypto_rfc3686_free(struct skcipher_instance *inst)
{
	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);

	crypto_drop_skcipher(spawn);
	kfree(inst);
}

static int crypto_rfc3686_create(struct crypto_template *tmpl,
				 struct rtattr **tb)
{
	struct crypto_attr_type *algt;
	struct skcipher_instance *inst;
	struct skcipher_alg *alg;
	struct crypto_skcipher_spawn *spawn;
	const char *cipher_name;
	u32 mask;

	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return PTR_ERR(algt);

	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
		return -EINVAL;

	cipher_name = crypto_attr_alg_name(tb[1]);
	if (IS_ERR(cipher_name))
		return PTR_ERR(cipher_name);

	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
	if (!inst)
		return -ENOMEM;

	mask = crypto_requires_sync(algt->type, algt->mask) |
		crypto_requires_off(algt->type, algt->mask,
				    CRYPTO_ALG_NEED_FALLBACK);

	spawn = skcipher_instance_ctx(inst);

	crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
	err = crypto_grab_skcipher(spawn, cipher_name, 0, mask);
	if (err)
		goto err_free_inst;

	alg = crypto_spawn_skcipher_alg(spawn);

	/* We only support 16-byte blocks. */
	err = -EINVAL;
	if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
		goto err_drop_spawn;

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

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
		     "rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
		goto err_drop_spawn;
	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "rfc3686(%s)", alg->base.cra_driver_name) >=
	    CRYPTO_MAX_ALG_NAME)
		goto err_drop_spawn;

	inst->alg.base.cra_priority = alg->base.cra_priority;
	inst->alg.base.cra_blocksize = 1;
	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;

	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;

	inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
	inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
	inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
				CTR_RFC3686_NONCE_SIZE;
	inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
				CTR_RFC3686_NONCE_SIZE;

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

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

	inst->alg.init = crypto_rfc3686_init_tfm;
	inst->alg.exit = crypto_rfc3686_exit_tfm;

	inst->free = crypto_rfc3686_free;

	err = skcipher_register_instance(tmpl, inst);
	if (err)
		goto err_drop_spawn;

out:
	return err;

err_drop_spawn:
	crypto_drop_skcipher(spawn);
err_free_inst:
	kfree(inst);
	goto out;
}

static struct crypto_template crypto_rfc3686_tmpl = {
	.name = "rfc3686",
	.create = crypto_rfc3686_create,
	.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_CRYPTO("rfc3686");
MODULE_ALIAS_CRYPTO("ctr");
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>
69d3150c	15	#include <crypto/internal/skcipher.h>
23e353c8 JL	16	#include <linux/err.h>
	17	#include <linux/init.h>
	18	#include <linux/kernel.h>
	19	#include <linux/module.h>
	20	#include <linux/random.h>
	21	#include <linux/scatterlist.h>
	22	#include <linux/slab.h>
	23
23e353c8 JL	24	struct crypto_ctr_ctx {
23e353c8 JL	25	struct crypto_cipher *child;
5311f248 HX	26	};
	27
	28	struct crypto_rfc3686_ctx {
b2b39c2f	29	struct crypto_skcipher *child;
5311f248	30	u8 nonce[CTR_RFC3686_NONCE_SIZE];
23e353c8 JL	31	};
23e353c8 JL	32
69d3150c JK	33	struct crypto_rfc3686_req_ctx {
69d3150c JK	34	u8 iv[CTR_RFC3686_BLOCK_SIZE];
b2b39c2f	35	struct skcipher_request subreq CRYPTO_MINALIGN_ATTR;
69d3150c JK	36	};
69d3150c JK	37
23e353c8 JL	38	static int crypto_ctr_setkey(struct crypto_tfm parent, const u8 key,
	39	unsigned int keylen)
	40	{
	41	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(parent);
	42	struct crypto_cipher *child = ctx->child;
5311f248	43	int err;
23e353c8 JL	44
	45	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	46	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
	47	CRYPTO_TFM_REQ_MASK);
	48	err = crypto_cipher_setkey(child, key, keylen);
	49	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
	50	CRYPTO_TFM_RES_MASK);
	51
	52	return err;
	53	}
	54
0971eb0d	55	static void crypto_ctr_crypt_final(struct blkcipher_walk *walk,
5311f248	56	struct crypto_cipher *tfm)
0971eb0d HX	57	{
0971eb0d HX	58	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248 HX	59	unsigned long alignmask = crypto_cipher_alignmask(tfm);
5311f248 HX	60	u8 *ctrblk = walk->iv;
6650c4de	61	u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
5311f248	62	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
0971eb0d HX	63	u8 *src = walk->src.virt.addr;
	64	u8 *dst = walk->dst.virt.addr;
	65	unsigned int nbytes = walk->nbytes;
	66
	67	crypto_cipher_encrypt_one(tfm, keystream, ctrblk);
45fe93df	68	crypto_xor_cpy(dst, keystream, src, nbytes);
5311f248 HX	69
5311f248 HX	70	crypto_inc(ctrblk, bsize);
0971eb0d HX	71	}
0971eb0d HX	72
23e353c8	73	static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
5311f248	74	struct crypto_cipher *tfm)
23e353c8 JL	75	{
	76	void (fn)(struct crypto_tfm , u8 , const u8 ) =
	77	crypto_cipher_alg(tfm)->cia_encrypt;
	78	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248	79	u8 *ctrblk = walk->iv;
23e353c8 JL	80	u8 *src = walk->src.virt.addr;
	81	u8 *dst = walk->dst.virt.addr;
	82	unsigned int nbytes = walk->nbytes;
	83
	84	do {
	85	/* create keystream */
0971eb0d HX	86	fn(crypto_cipher_tfm(tfm), dst, ctrblk);
0971eb0d HX	87	crypto_xor(dst, src, bsize);
23e353c8 JL	88
23e353c8 JL	89	/* increment counter in counterblock */
5311f248	90	crypto_inc(ctrblk, bsize);
23e353c8	91
23e353c8 JL	92	src += bsize;
23e353c8 JL	93	dst += bsize;
0971eb0d	94	} while ((nbytes -= bsize) >= bsize);
23e353c8	95
0971eb0d	96	return nbytes;
23e353c8 JL	97	}
	98
	99	static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
5311f248	100	struct crypto_cipher *tfm)
23e353c8 JL	101	{
	102	void (fn)(struct crypto_tfm , u8 , const u8 ) =
	103	crypto_cipher_alg(tfm)->cia_encrypt;
	104	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248	105	unsigned long alignmask = crypto_cipher_alignmask(tfm);
23e353c8	106	unsigned int nbytes = walk->nbytes;
5311f248	107	u8 *ctrblk = walk->iv;
23e353c8	108	u8 *src = walk->src.virt.addr;
6650c4de	109	u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
5311f248	110	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
23e353c8 JL	111
	112	do {
	113	/* create keystream */
	114	fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
0971eb0d	115	crypto_xor(src, keystream, bsize);
23e353c8 JL	116
23e353c8 JL	117	/* increment counter in counterblock */
5311f248	118	crypto_inc(ctrblk, bsize);
23e353c8	119
23e353c8	120	src += bsize;
0971eb0d	121	} while ((nbytes -= bsize) >= bsize);
23e353c8	122
0971eb0d	123	return nbytes;
23e353c8 JL	124	}
	125
	126	static int crypto_ctr_crypt(struct blkcipher_desc *desc,
	127	struct scatterlist dst, struct scatterlist src,
	128	unsigned int nbytes)
	129	{
	130	struct blkcipher_walk walk;
	131	struct crypto_blkcipher *tfm = desc->tfm;
	132	struct crypto_ctr_ctx *ctx = crypto_blkcipher_ctx(tfm);
	133	struct crypto_cipher *child = ctx->child;
	134	unsigned int bsize = crypto_cipher_blocksize(child);
23e353c8 JL	135	int err;
	136
	137	blkcipher_walk_init(&walk, dst, src, nbytes);
	138	err = blkcipher_walk_virt_block(desc, &walk, bsize);
	139
0971eb0d	140	while (walk.nbytes >= bsize) {
23e353c8	141	if (walk.src.virt.addr == walk.dst.virt.addr)
5311f248	142	nbytes = crypto_ctr_crypt_inplace(&walk, child);
23e353c8	143	else
5311f248	144	nbytes = crypto_ctr_crypt_segment(&walk, child);
23e353c8 JL	145
	146	err = blkcipher_walk_done(desc, &walk, nbytes);
	147	}
0971eb0d HX	148
0971eb0d HX	149	if (walk.nbytes) {
5311f248	150	crypto_ctr_crypt_final(&walk, child);
0971eb0d HX	151	err = blkcipher_walk_done(desc, &walk, 0);
	152	}
	153
23e353c8 JL	154	return err;
	155	}
	156
	157	static int crypto_ctr_init_tfm(struct crypto_tfm *tfm)
	158	{
	159	struct crypto_instance inst = (void )tfm->__crt_alg;
5311f248	160	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
23e353c8 JL	161	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
	162	struct crypto_cipher *cipher;
	163
5311f248	164	cipher = crypto_spawn_cipher(spawn);
23e353c8 JL	165	if (IS_ERR(cipher))
	166	return PTR_ERR(cipher);
	167
	168	ctx->child = cipher;
	169
	170	return 0;
	171	}
	172
	173	static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm)
	174	{
	175	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
	176
23e353c8 JL	177	crypto_free_cipher(ctx->child);
	178	}
	179
	180	static struct crypto_instance crypto_ctr_alloc(struct rtattr *tb)
	181	{
	182	struct crypto_instance *inst;
d2c2a85c	183	struct crypto_attr_type *algt;
23e353c8	184	struct crypto_alg *alg;
d2c2a85c	185	u32 mask;
23e353c8 JL	186	int err;
	187
	188	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
	189	if (err)
	190	return ERR_PTR(err);
	191
d2c2a85c MC	192	algt = crypto_get_attr_type(tb);
	193	if (IS_ERR(algt))
	194	return ERR_CAST(algt);
	195
	196	mask = CRYPTO_ALG_TYPE_MASK \|
	197	crypto_requires_off(algt->type, algt->mask,
	198	CRYPTO_ALG_NEED_FALLBACK);
	199
	200	alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER, mask);
23e353c8	201	if (IS_ERR(alg))
8db05078	202	return ERR_CAST(alg);
23e353c8	203
5311f248	204	/* Block size must be >= 4 bytes. */
23e353c8	205	err = -EINVAL;
5311f248	206	if (alg->cra_blocksize < 4)
23e353c8 JL	207	goto out_put_alg;
23e353c8 JL	208
3f8214ea	209	/* If this is false we'd fail the alignment of crypto_inc. */
5311f248	210	if (alg->cra_blocksize % 4)
3f8214ea HX	211	goto out_put_alg;
3f8214ea HX	212
5311f248 HX	213	inst = crypto_alloc_instance("ctr", alg);
	214	if (IS_ERR(inst))
	215	goto out;
23e353c8	216
23e353c8 JL	217	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	218	inst->alg.cra_priority = alg->cra_priority;
	219	inst->alg.cra_blocksize = 1;
db91af0f	220	inst->alg.cra_alignmask = alg->cra_alignmask;
23e353c8 JL	221	inst->alg.cra_type = &crypto_blkcipher_type;
23e353c8 JL	222
5311f248 HX	223	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
	224	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
	225	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
23e353c8 JL	226
	227	inst->alg.cra_ctxsize = sizeof(struct crypto_ctr_ctx);
	228
	229	inst->alg.cra_init = crypto_ctr_init_tfm;
	230	inst->alg.cra_exit = crypto_ctr_exit_tfm;
	231
	232	inst->alg.cra_blkcipher.setkey = crypto_ctr_setkey;
	233	inst->alg.cra_blkcipher.encrypt = crypto_ctr_crypt;
	234	inst->alg.cra_blkcipher.decrypt = crypto_ctr_crypt;
	235
aef27136 HX	236	inst->alg.cra_blkcipher.geniv = "chainiv";
aef27136 HX	237
5311f248	238	out:
23e353c8	239	crypto_mod_put(alg);
23e353c8	240	return inst;
5311f248 HX	241
	242	out_put_alg:
	243	inst = ERR_PTR(err);
	244	goto out;
23e353c8 JL	245	}
	246
	247	static void crypto_ctr_free(struct crypto_instance *inst)
	248	{
5311f248	249	crypto_drop_spawn(crypto_instance_ctx(inst));
23e353c8 JL	250	kfree(inst);
	251	}
	252
	253	static struct crypto_template crypto_ctr_tmpl = {
	254	.name = "ctr",
	255	.alloc = crypto_ctr_alloc,
	256	.free = crypto_ctr_free,
	257	.module = THIS_MODULE,
	258	};
	259
b2b39c2f	260	static int crypto_rfc3686_setkey(struct crypto_skcipher *parent,
69d3150c	261	const u8 *key, unsigned int keylen)
5311f248	262	{
b2b39c2f HX	263	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
b2b39c2f HX	264	struct crypto_skcipher *child = ctx->child;
5311f248 HX	265	int err;
	266
	267	/* the nonce is stored in bytes at end of key */
	268	if (keylen < CTR_RFC3686_NONCE_SIZE)
	269	return -EINVAL;
	270
	271	memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
	272	CTR_RFC3686_NONCE_SIZE);
	273
	274	keylen -= CTR_RFC3686_NONCE_SIZE;
	275
b2b39c2f HX	276	crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	277	crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
	278	CRYPTO_TFM_REQ_MASK);
	279	err = crypto_skcipher_setkey(child, key, keylen);
	280	crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
	281	CRYPTO_TFM_RES_MASK);
5311f248 HX	282
	283	return err;
	284	}
	285
b2b39c2f	286	static int crypto_rfc3686_crypt(struct skcipher_request *req)
5311f248	287	{
b2b39c2f HX	288	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	289	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	290	struct crypto_skcipher *child = ctx->child;
	291	unsigned long align = crypto_skcipher_alignmask(tfm);
69d3150c	292	struct crypto_rfc3686_req_ctx *rctx =
b2b39c2f HX	293	(void )PTR_ALIGN((u8 )skcipher_request_ctx(req), align + 1);
b2b39c2f HX	294	struct skcipher_request *subreq = &rctx->subreq;
69d3150c	295	u8 *iv = rctx->iv;
5311f248 HX	296
	297	/* set up counter block */
	298	memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
b2b39c2f	299	memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
5311f248 HX	300
	301	/* initialize counter portion of counter block */
	302	(__be32 )(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
	303	cpu_to_be32(1);
	304
b2b39c2f HX	305	skcipher_request_set_tfm(subreq, child);
	306	skcipher_request_set_callback(subreq, req->base.flags,
	307	req->base.complete, req->base.data);
	308	skcipher_request_set_crypt(subreq, req->src, req->dst,
	309	req->cryptlen, iv);
5311f248	310
b2b39c2f	311	return crypto_skcipher_encrypt(subreq);
5311f248 HX	312	}
5311f248 HX	313
b2b39c2f	314	static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm)
5311f248	315	{
b2b39c2f HX	316	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
	317	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
	318	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	319	struct crypto_skcipher *cipher;
69d3150c	320	unsigned long align;
b2b39c2f	321	unsigned int reqsize;
5311f248	322
60425a8b	323	cipher = crypto_spawn_skcipher(spawn);
5311f248 HX	324	if (IS_ERR(cipher))
	325	return PTR_ERR(cipher);
	326
	327	ctx->child = cipher;
	328
b2b39c2f	329	align = crypto_skcipher_alignmask(tfm);
69d3150c	330	align &= ~(crypto_tfm_ctx_alignment() - 1);
b2b39c2f HX	331	reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) +
	332	crypto_skcipher_reqsize(cipher);
	333	crypto_skcipher_set_reqsize(tfm, reqsize);
69d3150c	334
5311f248 HX	335	return 0;
	336	}
	337
b2b39c2f	338	static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm)
5311f248	339	{
b2b39c2f HX	340	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	341
	342	crypto_free_skcipher(ctx->child);
	343	}
5311f248	344
b2b39c2f HX	345	static void crypto_rfc3686_free(struct skcipher_instance *inst)
	346	{
	347	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
	348
	349	crypto_drop_skcipher(spawn);
	350	kfree(inst);
5311f248 HX	351	}
5311f248 HX	352
b2b39c2f HX	353	static int crypto_rfc3686_create(struct crypto_template *tmpl,
b2b39c2f HX	354	struct rtattr **tb)
5311f248	355	{
69d3150c	356	struct crypto_attr_type *algt;
b2b39c2f HX	357	struct skcipher_instance *inst;
b2b39c2f HX	358	struct skcipher_alg *alg;
69d3150c JK	359	struct crypto_skcipher_spawn *spawn;
69d3150c JK	360	const char *cipher_name;
d2c2a85c MC	361	u32 mask;
d2c2a85c MC	362
5311f248 HX	363	int err;
5311f248 HX	364
69d3150c	365	algt = crypto_get_attr_type(tb);
69d3150c	366	if (IS_ERR(algt))
b2b39c2f	367	return PTR_ERR(algt);
5311f248	368
b2b39c2f HX	369	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
b2b39c2f HX	370	return -EINVAL;
69d3150c JK	371
69d3150c JK	372	cipher_name = crypto_attr_alg_name(tb[1]);
69d3150c	373	if (IS_ERR(cipher_name))
b2b39c2f	374	return PTR_ERR(cipher_name);
5311f248	375
69d3150c JK	376	inst = kzalloc(sizeof(inst) + sizeof(spawn), GFP_KERNEL);
69d3150c JK	377	if (!inst)
b2b39c2f	378	return -ENOMEM;
69d3150c	379
d2c2a85c MC	380	mask = crypto_requires_sync(algt->type, algt->mask) \|
	381	crypto_requires_off(algt->type, algt->mask,
	382	CRYPTO_ALG_NEED_FALLBACK);
	383
b2b39c2f	384	spawn = skcipher_instance_ctx(inst);
69d3150c	385
b2b39c2f	386	crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
d2c2a85c	387	err = crypto_grab_skcipher(spawn, cipher_name, 0, mask);
69d3150c JK	388	if (err)
	389	goto err_free_inst;
	390
b2b39c2f	391	alg = crypto_spawn_skcipher_alg(spawn);
69d3150c	392
5311f248 HX	393	/* We only support 16-byte blocks. */
5311f248 HX	394	err = -EINVAL;
b2b39c2f	395	if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
69d3150c	396	goto err_drop_spawn;
5311f248 HX	397
5311f248 HX	398	/* Not a stream cipher? */
b2b39c2f	399	if (alg->base.cra_blocksize != 1)
69d3150c	400	goto err_drop_spawn;
5311f248	401
69d3150c	402	err = -ENAMETOOLONG;
b2b39c2f HX	403	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
b2b39c2f HX	404	"rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
69d3150c	405	goto err_drop_spawn;
b2b39c2f HX	406	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
	407	"rfc3686(%s)", alg->base.cra_driver_name) >=
	408	CRYPTO_MAX_ALG_NAME)
69d3150c	409	goto err_drop_spawn;
5311f248	410
b2b39c2f HX	411	inst->alg.base.cra_priority = alg->base.cra_priority;
	412	inst->alg.base.cra_blocksize = 1;
	413	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
5311f248	414
b2b39c2f	415	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
69d3150c	416
b2b39c2f HX	417	inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
	418	inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
	419	inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
	420	CTR_RFC3686_NONCE_SIZE;
	421	inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
	422	CTR_RFC3686_NONCE_SIZE;
5311f248	423
b2b39c2f HX	424	inst->alg.setkey = crypto_rfc3686_setkey;
	425	inst->alg.encrypt = crypto_rfc3686_crypt;
	426	inst->alg.decrypt = crypto_rfc3686_crypt;
69d3150c	427
b2b39c2f	428	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
0a270321	429
b2b39c2f HX	430	inst->alg.init = crypto_rfc3686_init_tfm;
b2b39c2f HX	431	inst->alg.exit = crypto_rfc3686_exit_tfm;
5311f248	432
b2b39c2f	433	inst->free = crypto_rfc3686_free;
5311f248	434
b2b39c2f HX	435	err = skcipher_register_instance(tmpl, inst);
	436	if (err)
	437	goto err_drop_spawn;
	438
	439	out:
	440	return err;
5311f248	441
69d3150c JK	442	err_drop_spawn:
	443	crypto_drop_skcipher(spawn);
	444	err_free_inst:
	445	kfree(inst);
b2b39c2f	446	goto out;
5311f248 HX	447	}
	448
	449	static struct crypto_template crypto_rfc3686_tmpl = {
	450	.name = "rfc3686",
b2b39c2f	451	.create = crypto_rfc3686_create,
5311f248 HX	452	.module = THIS_MODULE,
	453	};
	454
23e353c8 JL	455	static int __init crypto_ctr_module_init(void)
23e353c8 JL	456	{
5311f248 HX	457	int err;
	458
	459	err = crypto_register_template(&crypto_ctr_tmpl);
	460	if (err)
	461	goto out;
	462
	463	err = crypto_register_template(&crypto_rfc3686_tmpl);
	464	if (err)
	465	goto out_drop_ctr;
	466
	467	out:
	468	return err;
	469
	470	out_drop_ctr:
	471	crypto_unregister_template(&crypto_ctr_tmpl);
	472	goto out;
23e353c8 JL	473	}
	474
	475	static void __exit crypto_ctr_module_exit(void)
	476	{
5311f248	477	crypto_unregister_template(&crypto_rfc3686_tmpl);
23e353c8 JL	478	crypto_unregister_template(&crypto_ctr_tmpl);
	479	}
	480
	481	module_init(crypto_ctr_module_init);
	482	module_exit(crypto_ctr_module_exit);
	483
	484	MODULE_LICENSE("GPL");
	485	MODULE_DESCRIPTION("CTR Counter block mode");
5d26a105	486	MODULE_ALIAS_CRYPTO("rfc3686");
4943ba16	487	MODULE_ALIAS_CRYPTO("ctr");