[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;

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
5311f248	236	out:
23e353c8	237	crypto_mod_put(alg);
23e353c8	238	return inst;
5311f248 HX	239
	240	out_put_alg:
	241	inst = ERR_PTR(err);
	242	goto out;
23e353c8 JL	243	}
	244
	245	static void crypto_ctr_free(struct crypto_instance *inst)
	246	{
5311f248	247	crypto_drop_spawn(crypto_instance_ctx(inst));
23e353c8 JL	248	kfree(inst);
	249	}
	250
	251	static struct crypto_template crypto_ctr_tmpl = {
	252	.name = "ctr",
	253	.alloc = crypto_ctr_alloc,
	254	.free = crypto_ctr_free,
	255	.module = THIS_MODULE,
	256	};
	257
b2b39c2f	258	static int crypto_rfc3686_setkey(struct crypto_skcipher *parent,
69d3150c	259	const u8 *key, unsigned int keylen)
5311f248	260	{
b2b39c2f HX	261	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
b2b39c2f HX	262	struct crypto_skcipher *child = ctx->child;
5311f248 HX	263	int err;
	264
	265	/* the nonce is stored in bytes at end of key */
	266	if (keylen < CTR_RFC3686_NONCE_SIZE)
	267	return -EINVAL;
	268
	269	memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
	270	CTR_RFC3686_NONCE_SIZE);
	271
	272	keylen -= CTR_RFC3686_NONCE_SIZE;
	273
b2b39c2f HX	274	crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	275	crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
	276	CRYPTO_TFM_REQ_MASK);
	277	err = crypto_skcipher_setkey(child, key, keylen);
	278	crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
	279	CRYPTO_TFM_RES_MASK);
5311f248 HX	280
	281	return err;
	282	}
	283
b2b39c2f	284	static int crypto_rfc3686_crypt(struct skcipher_request *req)
5311f248	285	{
b2b39c2f HX	286	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	287	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	288	struct crypto_skcipher *child = ctx->child;
	289	unsigned long align = crypto_skcipher_alignmask(tfm);
69d3150c	290	struct crypto_rfc3686_req_ctx *rctx =
b2b39c2f HX	291	(void )PTR_ALIGN((u8 )skcipher_request_ctx(req), align + 1);
b2b39c2f HX	292	struct skcipher_request *subreq = &rctx->subreq;
69d3150c	293	u8 *iv = rctx->iv;
5311f248 HX	294
	295	/* set up counter block */
	296	memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
b2b39c2f	297	memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
5311f248 HX	298
	299	/* initialize counter portion of counter block */
	300	(__be32 )(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
	301	cpu_to_be32(1);
	302
b2b39c2f HX	303	skcipher_request_set_tfm(subreq, child);
	304	skcipher_request_set_callback(subreq, req->base.flags,
	305	req->base.complete, req->base.data);
	306	skcipher_request_set_crypt(subreq, req->src, req->dst,
	307	req->cryptlen, iv);
5311f248	308
b2b39c2f	309	return crypto_skcipher_encrypt(subreq);
5311f248 HX	310	}
5311f248 HX	311
b2b39c2f	312	static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm)
5311f248	313	{
b2b39c2f HX	314	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
	315	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
	316	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	317	struct crypto_skcipher *cipher;
69d3150c	318	unsigned long align;
b2b39c2f	319	unsigned int reqsize;
5311f248	320
60425a8b	321	cipher = crypto_spawn_skcipher(spawn);
5311f248 HX	322	if (IS_ERR(cipher))
	323	return PTR_ERR(cipher);
	324
	325	ctx->child = cipher;
	326
b2b39c2f	327	align = crypto_skcipher_alignmask(tfm);
69d3150c	328	align &= ~(crypto_tfm_ctx_alignment() - 1);
b2b39c2f HX	329	reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) +
	330	crypto_skcipher_reqsize(cipher);
	331	crypto_skcipher_set_reqsize(tfm, reqsize);
69d3150c	332
5311f248 HX	333	return 0;
	334	}
	335
b2b39c2f	336	static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm)
5311f248	337	{
b2b39c2f HX	338	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	339
	340	crypto_free_skcipher(ctx->child);
	341	}
5311f248	342
b2b39c2f HX	343	static void crypto_rfc3686_free(struct skcipher_instance *inst)
	344	{
	345	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
	346
	347	crypto_drop_skcipher(spawn);
	348	kfree(inst);
5311f248 HX	349	}
5311f248 HX	350
b2b39c2f HX	351	static int crypto_rfc3686_create(struct crypto_template *tmpl,
b2b39c2f HX	352	struct rtattr **tb)
5311f248	353	{
69d3150c	354	struct crypto_attr_type *algt;
b2b39c2f HX	355	struct skcipher_instance *inst;
b2b39c2f HX	356	struct skcipher_alg *alg;
69d3150c JK	357	struct crypto_skcipher_spawn *spawn;
69d3150c JK	358	const char *cipher_name;
d2c2a85c MC	359	u32 mask;
d2c2a85c MC	360
5311f248 HX	361	int err;
5311f248 HX	362
69d3150c	363	algt = crypto_get_attr_type(tb);
69d3150c	364	if (IS_ERR(algt))
b2b39c2f	365	return PTR_ERR(algt);
5311f248	366
b2b39c2f HX	367	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
b2b39c2f HX	368	return -EINVAL;
69d3150c JK	369
69d3150c JK	370	cipher_name = crypto_attr_alg_name(tb[1]);
69d3150c	371	if (IS_ERR(cipher_name))
b2b39c2f	372	return PTR_ERR(cipher_name);
5311f248	373
69d3150c JK	374	inst = kzalloc(sizeof(inst) + sizeof(spawn), GFP_KERNEL);
69d3150c JK	375	if (!inst)
b2b39c2f	376	return -ENOMEM;
69d3150c	377
d2c2a85c MC	378	mask = crypto_requires_sync(algt->type, algt->mask) \|
	379	crypto_requires_off(algt->type, algt->mask,
	380	CRYPTO_ALG_NEED_FALLBACK);
	381
b2b39c2f	382	spawn = skcipher_instance_ctx(inst);
69d3150c	383
b2b39c2f	384	crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
d2c2a85c	385	err = crypto_grab_skcipher(spawn, cipher_name, 0, mask);
69d3150c JK	386	if (err)
	387	goto err_free_inst;
	388
b2b39c2f	389	alg = crypto_spawn_skcipher_alg(spawn);
69d3150c	390
5311f248 HX	391	/* We only support 16-byte blocks. */
5311f248 HX	392	err = -EINVAL;
b2b39c2f	393	if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
69d3150c	394	goto err_drop_spawn;
5311f248 HX	395
5311f248 HX	396	/* Not a stream cipher? */
b2b39c2f	397	if (alg->base.cra_blocksize != 1)
69d3150c	398	goto err_drop_spawn;
5311f248	399
69d3150c	400	err = -ENAMETOOLONG;
b2b39c2f HX	401	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
b2b39c2f HX	402	"rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
69d3150c	403	goto err_drop_spawn;
b2b39c2f HX	404	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
	405	"rfc3686(%s)", alg->base.cra_driver_name) >=
	406	CRYPTO_MAX_ALG_NAME)
69d3150c	407	goto err_drop_spawn;
5311f248	408
b2b39c2f HX	409	inst->alg.base.cra_priority = alg->base.cra_priority;
	410	inst->alg.base.cra_blocksize = 1;
	411	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
5311f248	412
b2b39c2f	413	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
69d3150c	414
b2b39c2f HX	415	inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
	416	inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
	417	inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
	418	CTR_RFC3686_NONCE_SIZE;
	419	inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
	420	CTR_RFC3686_NONCE_SIZE;
5311f248	421
b2b39c2f HX	422	inst->alg.setkey = crypto_rfc3686_setkey;
	423	inst->alg.encrypt = crypto_rfc3686_crypt;
	424	inst->alg.decrypt = crypto_rfc3686_crypt;
69d3150c	425
b2b39c2f	426	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
0a270321	427
b2b39c2f HX	428	inst->alg.init = crypto_rfc3686_init_tfm;
b2b39c2f HX	429	inst->alg.exit = crypto_rfc3686_exit_tfm;
5311f248	430
b2b39c2f	431	inst->free = crypto_rfc3686_free;
5311f248	432
b2b39c2f HX	433	err = skcipher_register_instance(tmpl, inst);
	434	if (err)
	435	goto err_drop_spawn;
	436
	437	out:
	438	return err;
5311f248	439
69d3150c JK	440	err_drop_spawn:
	441	crypto_drop_skcipher(spawn);
	442	err_free_inst:
	443	kfree(inst);
b2b39c2f	444	goto out;
5311f248 HX	445	}
	446
	447	static struct crypto_template crypto_rfc3686_tmpl = {
	448	.name = "rfc3686",
b2b39c2f	449	.create = crypto_rfc3686_create,
5311f248 HX	450	.module = THIS_MODULE,
	451	};
	452
23e353c8 JL	453	static int __init crypto_ctr_module_init(void)
23e353c8 JL	454	{
5311f248 HX	455	int err;
	456
	457	err = crypto_register_template(&crypto_ctr_tmpl);
	458	if (err)
	459	goto out;
	460
	461	err = crypto_register_template(&crypto_rfc3686_tmpl);
	462	if (err)
	463	goto out_drop_ctr;
	464
	465	out:
	466	return err;
	467
	468	out_drop_ctr:
	469	crypto_unregister_template(&crypto_ctr_tmpl);
	470	goto out;
23e353c8 JL	471	}
	472
	473	static void __exit crypto_ctr_module_exit(void)
	474	{
5311f248	475	crypto_unregister_template(&crypto_rfc3686_tmpl);
23e353c8 JL	476	crypto_unregister_template(&crypto_ctr_tmpl);
	477	}
	478
	479	module_init(crypto_ctr_module_init);
	480	module_exit(crypto_ctr_module_exit);
	481
	482	MODULE_LICENSE("GPL");
	483	MODULE_DESCRIPTION("CTR Counter block mode");
5d26a105	484	MODULE_ALIAS_CRYPTO("rfc3686");
4943ba16	485	MODULE_ALIAS_CRYPTO("ctr");