[linux-2.6-block.git] / crypto / ctr.c

/*
 * CTR: Counter mode
 *
 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <crypto/algapi.h>
#include <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_ablkcipher *child;
	u8 nonce[CTR_RFC3686_NONCE_SIZE];
};

struct crypto_rfc3686_req_ctx {
	u8 iv[CTR_RFC3686_BLOCK_SIZE];
	struct ablkcipher_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_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_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 | (__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;

	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_ablkcipher *parent,
				 const u8 *key, unsigned int keylen)
{
	struct crypto_rfc3686_ctx *ctx = crypto_ablkcipher_ctx(parent);
	struct crypto_ablkcipher *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_ablkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_ablkcipher_set_flags(child, crypto_ablkcipher_get_flags(parent) &
				    CRYPTO_TFM_REQ_MASK);
	err = crypto_ablkcipher_setkey(child, key, keylen);
	crypto_ablkcipher_set_flags(parent, crypto_ablkcipher_get_flags(child) &
				    CRYPTO_TFM_RES_MASK);

	return err;
}

static int crypto_rfc3686_crypt(struct ablkcipher_request *req)
{
	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
	struct crypto_rfc3686_ctx *ctx = crypto_ablkcipher_ctx(tfm);
	struct crypto_ablkcipher *child = ctx->child;
	unsigned long align = crypto_ablkcipher_alignmask(tfm);
	struct crypto_rfc3686_req_ctx *rctx =
		(void *)PTR_ALIGN((u8 *)ablkcipher_request_ctx(req), align + 1);
	struct ablkcipher_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->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);

	ablkcipher_request_set_tfm(subreq, child);
	ablkcipher_request_set_callback(subreq, req->base.flags,
					req->base.complete, req->base.data);
	ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->nbytes,
				     iv);

	return crypto_ablkcipher_encrypt(subreq);
}

static int crypto_rfc3686_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = (void *)tfm->__crt_alg;
	struct crypto_skcipher_spawn *spawn = crypto_instance_ctx(inst);
	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_ablkcipher *cipher;
	unsigned long align;

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

	ctx->child = cipher;

	align = crypto_tfm_alg_alignmask(tfm);
	align &= ~(crypto_tfm_ctx_alignment() - 1);
	tfm->crt_ablkcipher.reqsize = align +
		sizeof(struct crypto_rfc3686_req_ctx) +
		crypto_ablkcipher_reqsize(cipher);

	return 0;
}

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

	crypto_free_ablkcipher(ctx->child);
}

static struct crypto_instance *crypto_rfc3686_alloc(struct rtattr **tb)
{
	struct crypto_attr_type *algt;
	struct crypto_instance *inst;
	struct crypto_alg *alg;
	struct crypto_skcipher_spawn *spawn;
	const char *cipher_name;
	int err;

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

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

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

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

	spawn = crypto_instance_ctx(inst);

	crypto_set_skcipher_spawn(spawn, inst);
	err = crypto_grab_skcipher(spawn, cipher_name, 0,
				   crypto_requires_sync(algt->type,
							algt->mask));
	if (err)
		goto err_free_inst;

	alg = crypto_skcipher_spawn_alg(spawn);

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

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

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

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

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER |
			      (alg->cra_flags & CRYPTO_ALG_ASYNC);
	inst->alg.cra_type = &crypto_ablkcipher_type;

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

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

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

	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;

	return inst;

err_drop_spawn:
	crypto_drop_skcipher(spawn);
err_free_inst:
	kfree(inst);
	return ERR_PTR(err);
}

static void crypto_rfc3686_free(struct crypto_instance *inst)
{
	struct crypto_skcipher_spawn *spawn = crypto_instance_ctx(inst);

	crypto_drop_skcipher(spawn);
	kfree(inst);
}

static struct crypto_template crypto_rfc3686_tmpl = {
	.name = "rfc3686",
	.alloc = crypto_rfc3686_alloc,
	.free = crypto_rfc3686_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_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 <latten@us.ibm.com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the Free
	8	* Software Foundation; either version 2 of the License, or (at your option)
	9	* any later version.
	10	*
	11	*/
	12
	13	#include <crypto/algapi.h>
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 {
69d3150c	29	struct crypto_ablkcipher *child;
5311f248	30	u8 nonce[CTR_RFC3686_NONCE_SIZE];
23e353c8 JL	31	};
23e353c8 JL	32
69d3150c JK	33	struct crypto_rfc3686_req_ctx {
	34	u8 iv[CTR_RFC3686_BLOCK_SIZE];
	35	struct ablkcipher_request subreq CRYPTO_MINALIGN_ATTR;
	36	};
	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;
	184	struct crypto_alg *alg;
23e353c8 JL	185	int err;
	186
	187	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
	188	if (err)
	189	return ERR_PTR(err);
	190
	191	alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
	192	CRYPTO_ALG_TYPE_MASK);
	193	if (IS_ERR(alg))
8db05078	194	return ERR_CAST(alg);
23e353c8	195
5311f248	196	/* Block size must be >= 4 bytes. */
23e353c8	197	err = -EINVAL;
5311f248	198	if (alg->cra_blocksize < 4)
23e353c8 JL	199	goto out_put_alg;
23e353c8 JL	200
3f8214ea	201	/* If this is false we'd fail the alignment of crypto_inc. */
5311f248	202	if (alg->cra_blocksize % 4)
3f8214ea HX	203	goto out_put_alg;
3f8214ea HX	204
5311f248 HX	205	inst = crypto_alloc_instance("ctr", alg);
	206	if (IS_ERR(inst))
	207	goto out;
23e353c8	208
23e353c8 JL	209	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	210	inst->alg.cra_priority = alg->cra_priority;
	211	inst->alg.cra_blocksize = 1;
0971eb0d	212	inst->alg.cra_alignmask = alg->cra_alignmask \| (__alignof__(u32) - 1);
23e353c8 JL	213	inst->alg.cra_type = &crypto_blkcipher_type;
23e353c8 JL	214
5311f248 HX	215	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
	216	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
	217	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
23e353c8 JL	218
	219	inst->alg.cra_ctxsize = sizeof(struct crypto_ctr_ctx);
	220
	221	inst->alg.cra_init = crypto_ctr_init_tfm;
	222	inst->alg.cra_exit = crypto_ctr_exit_tfm;
	223
	224	inst->alg.cra_blkcipher.setkey = crypto_ctr_setkey;
	225	inst->alg.cra_blkcipher.encrypt = crypto_ctr_crypt;
	226	inst->alg.cra_blkcipher.decrypt = crypto_ctr_crypt;
	227
aef27136 HX	228	inst->alg.cra_blkcipher.geniv = "chainiv";
aef27136 HX	229
5311f248	230	out:
23e353c8	231	crypto_mod_put(alg);
23e353c8	232	return inst;
5311f248 HX	233
	234	out_put_alg:
	235	inst = ERR_PTR(err);
	236	goto out;
23e353c8 JL	237	}
	238
	239	static void crypto_ctr_free(struct crypto_instance *inst)
	240	{
5311f248	241	crypto_drop_spawn(crypto_instance_ctx(inst));
23e353c8 JL	242	kfree(inst);
	243	}
	244
	245	static struct crypto_template crypto_ctr_tmpl = {
	246	.name = "ctr",
	247	.alloc = crypto_ctr_alloc,
	248	.free = crypto_ctr_free,
	249	.module = THIS_MODULE,
	250	};
	251
69d3150c JK	252	static int crypto_rfc3686_setkey(struct crypto_ablkcipher *parent,
69d3150c JK	253	const u8 *key, unsigned int keylen)
5311f248	254	{
69d3150c JK	255	struct crypto_rfc3686_ctx *ctx = crypto_ablkcipher_ctx(parent);
69d3150c JK	256	struct crypto_ablkcipher *child = ctx->child;
5311f248 HX	257	int err;
	258
	259	/* the nonce is stored in bytes at end of key */
	260	if (keylen < CTR_RFC3686_NONCE_SIZE)
	261	return -EINVAL;
	262
	263	memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
	264	CTR_RFC3686_NONCE_SIZE);
	265
	266	keylen -= CTR_RFC3686_NONCE_SIZE;
	267
69d3150c JK	268	crypto_ablkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	269	crypto_ablkcipher_set_flags(child, crypto_ablkcipher_get_flags(parent) &
	270	CRYPTO_TFM_REQ_MASK);
	271	err = crypto_ablkcipher_setkey(child, key, keylen);
	272	crypto_ablkcipher_set_flags(parent, crypto_ablkcipher_get_flags(child) &
	273	CRYPTO_TFM_RES_MASK);
5311f248 HX	274
	275	return err;
	276	}
	277
69d3150c	278	static int crypto_rfc3686_crypt(struct ablkcipher_request *req)
5311f248	279	{
69d3150c JK	280	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
	281	struct crypto_rfc3686_ctx *ctx = crypto_ablkcipher_ctx(tfm);
	282	struct crypto_ablkcipher *child = ctx->child;
	283	unsigned long align = crypto_ablkcipher_alignmask(tfm);
	284	struct crypto_rfc3686_req_ctx *rctx =
	285	(void )PTR_ALIGN((u8 )ablkcipher_request_ctx(req), align + 1);
	286	struct ablkcipher_request *subreq = &rctx->subreq;
	287	u8 *iv = rctx->iv;
5311f248 HX	288
	289	/* set up counter block */
	290	memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
69d3150c	291	memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->info, CTR_RFC3686_IV_SIZE);
5311f248 HX	292
	293	/* initialize counter portion of counter block */
	294	(__be32 )(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
	295	cpu_to_be32(1);
	296
69d3150c JK	297	ablkcipher_request_set_tfm(subreq, child);
	298	ablkcipher_request_set_callback(subreq, req->base.flags,
	299	req->base.complete, req->base.data);
	300	ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->nbytes,
	301	iv);
5311f248	302
69d3150c	303	return crypto_ablkcipher_encrypt(subreq);
5311f248 HX	304	}
	305
	306	static int crypto_rfc3686_init_tfm(struct crypto_tfm *tfm)
	307	{
	308	struct crypto_instance inst = (void )tfm->__crt_alg;
69d3150c	309	struct crypto_skcipher_spawn *spawn = crypto_instance_ctx(inst);
5311f248	310	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);
69d3150c JK	311	struct crypto_ablkcipher *cipher;
69d3150c JK	312	unsigned long align;
5311f248	313
69d3150c	314	cipher = crypto_spawn_skcipher(spawn);
5311f248 HX	315	if (IS_ERR(cipher))
	316	return PTR_ERR(cipher);
	317
	318	ctx->child = cipher;
	319
69d3150c JK	320	align = crypto_tfm_alg_alignmask(tfm);
	321	align &= ~(crypto_tfm_ctx_alignment() - 1);
	322	tfm->crt_ablkcipher.reqsize = align +
	323	sizeof(struct crypto_rfc3686_req_ctx) +
	324	crypto_ablkcipher_reqsize(cipher);
	325
5311f248 HX	326	return 0;
	327	}
	328
	329	static void crypto_rfc3686_exit_tfm(struct crypto_tfm *tfm)
	330	{
	331	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);
	332
69d3150c	333	crypto_free_ablkcipher(ctx->child);
5311f248 HX	334	}
	335
	336	static struct crypto_instance crypto_rfc3686_alloc(struct rtattr *tb)
	337	{
69d3150c	338	struct crypto_attr_type *algt;
5311f248 HX	339	struct crypto_instance *inst;
5311f248 HX	340	struct crypto_alg *alg;
69d3150c JK	341	struct crypto_skcipher_spawn *spawn;
69d3150c JK	342	const char *cipher_name;
5311f248 HX	343	int err;
5311f248 HX	344
69d3150c	345	algt = crypto_get_attr_type(tb);
69d3150c	346	if (IS_ERR(algt))
32dc43e4	347	return ERR_CAST(algt);
5311f248	348
69d3150c JK	349	if ((algt->type ^ CRYPTO_ALG_TYPE_BLKCIPHER) & algt->mask)
	350	return ERR_PTR(-EINVAL);
	351
	352	cipher_name = crypto_attr_alg_name(tb[1]);
69d3150c	353	if (IS_ERR(cipher_name))
32dc43e4	354	return ERR_CAST(cipher_name);
5311f248	355
69d3150c JK	356	inst = kzalloc(sizeof(inst) + sizeof(spawn), GFP_KERNEL);
	357	if (!inst)
	358	return ERR_PTR(-ENOMEM);
	359
	360	spawn = crypto_instance_ctx(inst);
	361
	362	crypto_set_skcipher_spawn(spawn, inst);
	363	err = crypto_grab_skcipher(spawn, cipher_name, 0,
	364	crypto_requires_sync(algt->type,
	365	algt->mask));
	366	if (err)
	367	goto err_free_inst;
	368
	369	alg = crypto_skcipher_spawn_alg(spawn);
	370
5311f248 HX	371	/* We only support 16-byte blocks. */
5311f248 HX	372	err = -EINVAL;
69d3150c JK	373	if (alg->cra_ablkcipher.ivsize != CTR_RFC3686_BLOCK_SIZE)
69d3150c JK	374	goto err_drop_spawn;
5311f248 HX	375
	376	/* Not a stream cipher? */
	377	if (alg->cra_blocksize != 1)
69d3150c	378	goto err_drop_spawn;
5311f248	379
69d3150c JK	380	err = -ENAMETOOLONG;
	381	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "rfc3686(%s)",
	382	alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
	383	goto err_drop_spawn;
	384	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
	385	"rfc3686(%s)", alg->cra_driver_name) >=
	386	CRYPTO_MAX_ALG_NAME)
	387	goto err_drop_spawn;
5311f248	388
5311f248 HX	389	inst->alg.cra_priority = alg->cra_priority;
	390	inst->alg.cra_blocksize = 1;
	391	inst->alg.cra_alignmask = alg->cra_alignmask;
5311f248	392
69d3150c JK	393	inst->alg.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER \|
	394	(alg->cra_flags & CRYPTO_ALG_ASYNC);
	395	inst->alg.cra_type = &crypto_ablkcipher_type;
	396
	397	inst->alg.cra_ablkcipher.ivsize = CTR_RFC3686_IV_SIZE;
	398	inst->alg.cra_ablkcipher.min_keysize =
	399	alg->cra_ablkcipher.min_keysize + CTR_RFC3686_NONCE_SIZE;
	400	inst->alg.cra_ablkcipher.max_keysize =
	401	alg->cra_ablkcipher.max_keysize + CTR_RFC3686_NONCE_SIZE;
5311f248	402
69d3150c JK	403	inst->alg.cra_ablkcipher.geniv = "seqiv";
	404
	405	inst->alg.cra_ablkcipher.setkey = crypto_rfc3686_setkey;
	406	inst->alg.cra_ablkcipher.encrypt = crypto_rfc3686_crypt;
	407	inst->alg.cra_ablkcipher.decrypt = crypto_rfc3686_crypt;
0a270321	408
5311f248 HX	409	inst->alg.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
	410
	411	inst->alg.cra_init = crypto_rfc3686_init_tfm;
	412	inst->alg.cra_exit = crypto_rfc3686_exit_tfm;
	413
5311f248 HX	414	return inst;
5311f248 HX	415
69d3150c JK	416	err_drop_spawn:
	417	crypto_drop_skcipher(spawn);
	418	err_free_inst:
	419	kfree(inst);
	420	return ERR_PTR(err);
	421	}
	422
	423	static void crypto_rfc3686_free(struct crypto_instance *inst)
	424	{
	425	struct crypto_skcipher_spawn *spawn = crypto_instance_ctx(inst);
	426
	427	crypto_drop_skcipher(spawn);
	428	kfree(inst);
5311f248 HX	429	}
	430
	431	static struct crypto_template crypto_rfc3686_tmpl = {
	432	.name = "rfc3686",
	433	.alloc = crypto_rfc3686_alloc,
69d3150c	434	.free = crypto_rfc3686_free,
5311f248 HX	435	.module = THIS_MODULE,
	436	};
	437
23e353c8 JL	438	static int __init crypto_ctr_module_init(void)
23e353c8 JL	439	{
5311f248 HX	440	int err;
	441
	442	err = crypto_register_template(&crypto_ctr_tmpl);
	443	if (err)
	444	goto out;
	445
	446	err = crypto_register_template(&crypto_rfc3686_tmpl);
	447	if (err)
	448	goto out_drop_ctr;
	449
	450	out:
	451	return err;
	452
	453	out_drop_ctr:
	454	crypto_unregister_template(&crypto_ctr_tmpl);
	455	goto out;
23e353c8 JL	456	}
	457
	458	static void __exit crypto_ctr_module_exit(void)
	459	{
5311f248	460	crypto_unregister_template(&crypto_rfc3686_tmpl);
23e353c8 JL	461	crypto_unregister_template(&crypto_ctr_tmpl);
	462	}
	463
	464	module_init(crypto_ctr_module_init);
	465	module_exit(crypto_ctr_module_exit);
	466
	467	MODULE_LICENSE("GPL");
	468	MODULE_DESCRIPTION("CTR Counter block mode");
5d26a105	469	MODULE_ALIAS_CRYPTO("rfc3686");
4943ba16	470	MODULE_ALIAS_CRYPTO("ctr");