[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[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_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);
	60	u8 *ctrblk = walk->iv;
	61	u8 tmp[bsize + alignmask];
	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);
	68	crypto_xor(keystream, src, nbytes);
	69	memcpy(dst, keystream, nbytes);
5311f248 HX	70
5311f248 HX	71	crypto_inc(ctrblk, bsize);
0971eb0d HX	72	}
0971eb0d HX	73
23e353c8	74	static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
5311f248	75	struct crypto_cipher *tfm)
23e353c8 JL	76	{
	77	void (fn)(struct crypto_tfm , u8 , const u8 ) =
	78	crypto_cipher_alg(tfm)->cia_encrypt;
	79	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248	80	u8 *ctrblk = walk->iv;
23e353c8 JL	81	u8 *src = walk->src.virt.addr;
	82	u8 *dst = walk->dst.virt.addr;
	83	unsigned int nbytes = walk->nbytes;
	84
	85	do {
	86	/* create keystream */
0971eb0d HX	87	fn(crypto_cipher_tfm(tfm), dst, ctrblk);
0971eb0d HX	88	crypto_xor(dst, src, bsize);
23e353c8 JL	89
23e353c8 JL	90	/* increment counter in counterblock */
5311f248	91	crypto_inc(ctrblk, bsize);
23e353c8	92
23e353c8 JL	93	src += bsize;
23e353c8 JL	94	dst += bsize;
0971eb0d	95	} while ((nbytes -= bsize) >= bsize);
23e353c8	96
0971eb0d	97	return nbytes;
23e353c8 JL	98	}
	99
	100	static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
5311f248	101	struct crypto_cipher *tfm)
23e353c8 JL	102	{
	103	void (fn)(struct crypto_tfm , u8 , const u8 ) =
	104	crypto_cipher_alg(tfm)->cia_encrypt;
	105	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248	106	unsigned long alignmask = crypto_cipher_alignmask(tfm);
23e353c8	107	unsigned int nbytes = walk->nbytes;
5311f248	108	u8 *ctrblk = walk->iv;
23e353c8	109	u8 *src = walk->src.virt.addr;
5311f248 HX	110	u8 tmp[bsize + alignmask];
5311f248 HX	111	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
23e353c8 JL	112
	113	do {
	114	/* create keystream */
	115	fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
0971eb0d	116	crypto_xor(src, keystream, bsize);
23e353c8 JL	117
23e353c8 JL	118	/* increment counter in counterblock */
5311f248	119	crypto_inc(ctrblk, bsize);
23e353c8	120
23e353c8	121	src += bsize;
0971eb0d	122	} while ((nbytes -= bsize) >= bsize);
23e353c8	123
0971eb0d	124	return nbytes;
23e353c8 JL	125	}
	126
	127	static int crypto_ctr_crypt(struct blkcipher_desc *desc,
	128	struct scatterlist dst, struct scatterlist src,
	129	unsigned int nbytes)
	130	{
	131	struct blkcipher_walk walk;
	132	struct crypto_blkcipher *tfm = desc->tfm;
	133	struct crypto_ctr_ctx *ctx = crypto_blkcipher_ctx(tfm);
	134	struct crypto_cipher *child = ctx->child;
	135	unsigned int bsize = crypto_cipher_blocksize(child);
23e353c8 JL	136	int err;
	137
	138	blkcipher_walk_init(&walk, dst, src, nbytes);
	139	err = blkcipher_walk_virt_block(desc, &walk, bsize);
	140
0971eb0d	141	while (walk.nbytes >= bsize) {
23e353c8	142	if (walk.src.virt.addr == walk.dst.virt.addr)
5311f248	143	nbytes = crypto_ctr_crypt_inplace(&walk, child);
23e353c8	144	else
5311f248	145	nbytes = crypto_ctr_crypt_segment(&walk, child);
23e353c8 JL	146
	147	err = blkcipher_walk_done(desc, &walk, nbytes);
	148	}
0971eb0d HX	149
0971eb0d HX	150	if (walk.nbytes) {
5311f248	151	crypto_ctr_crypt_final(&walk, child);
0971eb0d HX	152	err = blkcipher_walk_done(desc, &walk, 0);
	153	}
	154
23e353c8 JL	155	return err;
	156	}
	157
	158	static int crypto_ctr_init_tfm(struct crypto_tfm *tfm)
	159	{
	160	struct crypto_instance inst = (void )tfm->__crt_alg;
5311f248	161	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
23e353c8 JL	162	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
	163	struct crypto_cipher *cipher;
	164
5311f248	165	cipher = crypto_spawn_cipher(spawn);
23e353c8 JL	166	if (IS_ERR(cipher))
	167	return PTR_ERR(cipher);
	168
	169	ctx->child = cipher;
	170
	171	return 0;
	172	}
	173
	174	static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm)
	175	{
	176	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
	177
23e353c8 JL	178	crypto_free_cipher(ctx->child);
	179	}
	180
	181	static struct crypto_instance crypto_ctr_alloc(struct rtattr *tb)
	182	{
	183	struct crypto_instance *inst;
d2c2a85c	184	struct crypto_attr_type *algt;
23e353c8	185	struct crypto_alg *alg;
d2c2a85c	186	u32 mask;
23e353c8 JL	187	int err;
	188
	189	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
	190	if (err)
	191	return ERR_PTR(err);
	192
d2c2a85c MC	193	algt = crypto_get_attr_type(tb);
	194	if (IS_ERR(algt))
	195	return ERR_CAST(algt);
	196
	197	mask = CRYPTO_ALG_TYPE_MASK \|
	198	crypto_requires_off(algt->type, algt->mask,
	199	CRYPTO_ALG_NEED_FALLBACK);
	200
	201	alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER, mask);
23e353c8	202	if (IS_ERR(alg))
8db05078	203	return ERR_CAST(alg);
23e353c8	204
5311f248	205	/* Block size must be >= 4 bytes. */
23e353c8	206	err = -EINVAL;
5311f248	207	if (alg->cra_blocksize < 4)
23e353c8 JL	208	goto out_put_alg;
23e353c8 JL	209
3f8214ea	210	/* If this is false we'd fail the alignment of crypto_inc. */
5311f248	211	if (alg->cra_blocksize % 4)
3f8214ea HX	212	goto out_put_alg;
3f8214ea HX	213
5311f248 HX	214	inst = crypto_alloc_instance("ctr", alg);
	215	if (IS_ERR(inst))
	216	goto out;
23e353c8	217
23e353c8 JL	218	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	219	inst->alg.cra_priority = alg->cra_priority;
	220	inst->alg.cra_blocksize = 1;
db91af0f	221	inst->alg.cra_alignmask = alg->cra_alignmask;
23e353c8 JL	222	inst->alg.cra_type = &crypto_blkcipher_type;
23e353c8 JL	223
5311f248 HX	224	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
	225	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
	226	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
23e353c8 JL	227
	228	inst->alg.cra_ctxsize = sizeof(struct crypto_ctr_ctx);
	229
	230	inst->alg.cra_init = crypto_ctr_init_tfm;
	231	inst->alg.cra_exit = crypto_ctr_exit_tfm;
	232
	233	inst->alg.cra_blkcipher.setkey = crypto_ctr_setkey;
	234	inst->alg.cra_blkcipher.encrypt = crypto_ctr_crypt;
	235	inst->alg.cra_blkcipher.decrypt = crypto_ctr_crypt;
	236
aef27136 HX	237	inst->alg.cra_blkcipher.geniv = "chainiv";
aef27136 HX	238
5311f248	239	out:
23e353c8	240	crypto_mod_put(alg);
23e353c8	241	return inst;
5311f248 HX	242
	243	out_put_alg:
	244	inst = ERR_PTR(err);
	245	goto out;
23e353c8 JL	246	}
	247
	248	static void crypto_ctr_free(struct crypto_instance *inst)
	249	{
5311f248	250	crypto_drop_spawn(crypto_instance_ctx(inst));
23e353c8 JL	251	kfree(inst);
	252	}
	253
	254	static struct crypto_template crypto_ctr_tmpl = {
	255	.name = "ctr",
	256	.alloc = crypto_ctr_alloc,
	257	.free = crypto_ctr_free,
	258	.module = THIS_MODULE,
	259	};
	260
b2b39c2f	261	static int crypto_rfc3686_setkey(struct crypto_skcipher *parent,
69d3150c	262	const u8 *key, unsigned int keylen)
5311f248	263	{
b2b39c2f HX	264	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
b2b39c2f HX	265	struct crypto_skcipher *child = ctx->child;
5311f248 HX	266	int err;
	267
	268	/* the nonce is stored in bytes at end of key */
	269	if (keylen < CTR_RFC3686_NONCE_SIZE)
	270	return -EINVAL;
	271
	272	memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
	273	CTR_RFC3686_NONCE_SIZE);
	274
	275	keylen -= CTR_RFC3686_NONCE_SIZE;
	276
b2b39c2f HX	277	crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	278	crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
	279	CRYPTO_TFM_REQ_MASK);
	280	err = crypto_skcipher_setkey(child, key, keylen);
	281	crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
	282	CRYPTO_TFM_RES_MASK);
5311f248 HX	283
	284	return err;
	285	}
	286
b2b39c2f	287	static int crypto_rfc3686_crypt(struct skcipher_request *req)
5311f248	288	{
b2b39c2f HX	289	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	290	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	291	struct crypto_skcipher *child = ctx->child;
	292	unsigned long align = crypto_skcipher_alignmask(tfm);
69d3150c	293	struct crypto_rfc3686_req_ctx *rctx =
b2b39c2f HX	294	(void )PTR_ALIGN((u8 )skcipher_request_ctx(req), align + 1);
b2b39c2f HX	295	struct skcipher_request *subreq = &rctx->subreq;
69d3150c	296	u8 *iv = rctx->iv;
5311f248 HX	297
	298	/* set up counter block */
	299	memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
b2b39c2f	300	memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
5311f248 HX	301
	302	/* initialize counter portion of counter block */
	303	(__be32 )(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
	304	cpu_to_be32(1);
	305
b2b39c2f HX	306	skcipher_request_set_tfm(subreq, child);
	307	skcipher_request_set_callback(subreq, req->base.flags,
	308	req->base.complete, req->base.data);
	309	skcipher_request_set_crypt(subreq, req->src, req->dst,
	310	req->cryptlen, iv);
5311f248	311
b2b39c2f	312	return crypto_skcipher_encrypt(subreq);
5311f248 HX	313	}
5311f248 HX	314
b2b39c2f	315	static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm)
5311f248	316	{
b2b39c2f HX	317	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
	318	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
	319	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	320	struct crypto_skcipher *cipher;
69d3150c	321	unsigned long align;
b2b39c2f	322	unsigned int reqsize;
5311f248	323
60425a8b	324	cipher = crypto_spawn_skcipher(spawn);
5311f248 HX	325	if (IS_ERR(cipher))
	326	return PTR_ERR(cipher);
	327
	328	ctx->child = cipher;
	329
b2b39c2f	330	align = crypto_skcipher_alignmask(tfm);
69d3150c	331	align &= ~(crypto_tfm_ctx_alignment() - 1);
b2b39c2f HX	332	reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) +
	333	crypto_skcipher_reqsize(cipher);
	334	crypto_skcipher_set_reqsize(tfm, reqsize);
69d3150c	335
5311f248 HX	336	return 0;
	337	}
	338
b2b39c2f	339	static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm)
5311f248	340	{
b2b39c2f HX	341	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	342
	343	crypto_free_skcipher(ctx->child);
	344	}
5311f248	345
b2b39c2f HX	346	static void crypto_rfc3686_free(struct skcipher_instance *inst)
	347	{
	348	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
	349
	350	crypto_drop_skcipher(spawn);
	351	kfree(inst);
5311f248 HX	352	}
5311f248 HX	353
b2b39c2f HX	354	static int crypto_rfc3686_create(struct crypto_template *tmpl,
b2b39c2f HX	355	struct rtattr **tb)
5311f248	356	{
69d3150c	357	struct crypto_attr_type *algt;
b2b39c2f HX	358	struct skcipher_instance *inst;
b2b39c2f HX	359	struct skcipher_alg *alg;
69d3150c JK	360	struct crypto_skcipher_spawn *spawn;
69d3150c JK	361	const char *cipher_name;
d2c2a85c MC	362	u32 mask;
d2c2a85c MC	363
5311f248 HX	364	int err;
5311f248 HX	365
69d3150c	366	algt = crypto_get_attr_type(tb);
69d3150c	367	if (IS_ERR(algt))
b2b39c2f	368	return PTR_ERR(algt);
5311f248	369
b2b39c2f HX	370	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
b2b39c2f HX	371	return -EINVAL;
69d3150c JK	372
69d3150c JK	373	cipher_name = crypto_attr_alg_name(tb[1]);
69d3150c	374	if (IS_ERR(cipher_name))
b2b39c2f	375	return PTR_ERR(cipher_name);
5311f248	376
69d3150c JK	377	inst = kzalloc(sizeof(inst) + sizeof(spawn), GFP_KERNEL);
69d3150c JK	378	if (!inst)
b2b39c2f	379	return -ENOMEM;
69d3150c	380
d2c2a85c MC	381	mask = crypto_requires_sync(algt->type, algt->mask) \|
	382	crypto_requires_off(algt->type, algt->mask,
	383	CRYPTO_ALG_NEED_FALLBACK);
	384
b2b39c2f	385	spawn = skcipher_instance_ctx(inst);
69d3150c	386
b2b39c2f	387	crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
d2c2a85c	388	err = crypto_grab_skcipher(spawn, cipher_name, 0, mask);
69d3150c JK	389	if (err)
	390	goto err_free_inst;
	391
b2b39c2f	392	alg = crypto_spawn_skcipher_alg(spawn);
69d3150c	393
5311f248 HX	394	/* We only support 16-byte blocks. */
5311f248 HX	395	err = -EINVAL;
b2b39c2f	396	if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
69d3150c	397	goto err_drop_spawn;
5311f248 HX	398
5311f248 HX	399	/* Not a stream cipher? */
b2b39c2f	400	if (alg->base.cra_blocksize != 1)
69d3150c	401	goto err_drop_spawn;
5311f248	402
69d3150c	403	err = -ENAMETOOLONG;
b2b39c2f HX	404	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
b2b39c2f HX	405	"rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
69d3150c	406	goto err_drop_spawn;
b2b39c2f HX	407	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
	408	"rfc3686(%s)", alg->base.cra_driver_name) >=
	409	CRYPTO_MAX_ALG_NAME)
69d3150c	410	goto err_drop_spawn;
5311f248	411
b2b39c2f HX	412	inst->alg.base.cra_priority = alg->base.cra_priority;
	413	inst->alg.base.cra_blocksize = 1;
	414	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
5311f248	415
b2b39c2f	416	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
69d3150c	417
b2b39c2f HX	418	inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
	419	inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
	420	inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
	421	CTR_RFC3686_NONCE_SIZE;
	422	inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
	423	CTR_RFC3686_NONCE_SIZE;
5311f248	424
b2b39c2f HX	425	inst->alg.setkey = crypto_rfc3686_setkey;
	426	inst->alg.encrypt = crypto_rfc3686_crypt;
	427	inst->alg.decrypt = crypto_rfc3686_crypt;
69d3150c	428
b2b39c2f	429	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
0a270321	430
b2b39c2f HX	431	inst->alg.init = crypto_rfc3686_init_tfm;
b2b39c2f HX	432	inst->alg.exit = crypto_rfc3686_exit_tfm;
5311f248	433
b2b39c2f	434	inst->free = crypto_rfc3686_free;
5311f248	435
b2b39c2f HX	436	err = skcipher_register_instance(tmpl, inst);
	437	if (err)
	438	goto err_drop_spawn;
	439
	440	out:
	441	return err;
5311f248	442
69d3150c JK	443	err_drop_spawn:
	444	crypto_drop_skcipher(spawn);
	445	err_free_inst:
	446	kfree(inst);
b2b39c2f	447	goto out;
5311f248 HX	448	}
	449
	450	static struct crypto_template crypto_rfc3686_tmpl = {
	451	.name = "rfc3686",
b2b39c2f	452	.create = crypto_rfc3686_create,
5311f248 HX	453	.module = THIS_MODULE,
	454	};
	455
23e353c8 JL	456	static int __init crypto_ctr_module_init(void)
23e353c8 JL	457	{
5311f248 HX	458	int err;
	459
	460	err = crypto_register_template(&crypto_ctr_tmpl);
	461	if (err)
	462	goto out;
	463
	464	err = crypto_register_template(&crypto_rfc3686_tmpl);
	465	if (err)
	466	goto out_drop_ctr;
	467
	468	out:
	469	return err;
	470
	471	out_drop_ctr:
	472	crypto_unregister_template(&crypto_ctr_tmpl);
	473	goto out;
23e353c8 JL	474	}
	475
	476	static void __exit crypto_ctr_module_exit(void)
	477	{
5311f248	478	crypto_unregister_template(&crypto_rfc3686_tmpl);
23e353c8 JL	479	crypto_unregister_template(&crypto_ctr_tmpl);
	480	}
	481
	482	module_init(crypto_ctr_module_init);
	483	module_exit(crypto_ctr_module_exit);
	484
	485	MODULE_LICENSE("GPL");
	486	MODULE_DESCRIPTION("CTR Counter block mode");
5d26a105	487	MODULE_ALIAS_CRYPTO("rfc3686");
4943ba16	488	MODULE_ALIAS_CRYPTO("ctr");