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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * CTR: Counter mode
 *
 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
 */

#include <crypto/algapi.h>
#include <crypto/ctr.h>
#include <crypto/internal/cipher.h>
#include <crypto/internal/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

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 void crypto_ctr_crypt_final(struct skcipher_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 skcipher_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 skcipher_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 skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
	const unsigned int bsize = crypto_cipher_blocksize(cipher);
	struct skcipher_walk walk;
	unsigned int nbytes;
	int err;

	err = skcipher_walk_virt(&walk, req, false);

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

		err = skcipher_walk_done(&walk, nbytes);
	}

	if (walk.nbytes) {
		crypto_ctr_crypt_final(&walk, cipher);
		err = skcipher_walk_done(&walk, 0);
	}

	return err;
}

static int crypto_ctr_create(struct crypto_template *tmpl, struct rtattr **tb)
{
	struct skcipher_instance *inst;
	struct crypto_alg *alg;
	int err;

	inst = skcipher_alloc_instance_simple(tmpl, tb);
	if (IS_ERR(inst))
		return PTR_ERR(inst);

	alg = skcipher_ialg_simple(inst);

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

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

	/* CTR mode is a stream cipher. */
	inst->alg.base.cra_blocksize = 1;

	/*
	 * To simplify the implementation, configure the skcipher walk to only
	 * give a partial block at the very end, never earlier.
	 */
	inst->alg.chunksize = alg->cra_blocksize;

	inst->alg.encrypt = crypto_ctr_crypt;
	inst->alg.decrypt = crypto_ctr_crypt;

	err = skcipher_register_instance(tmpl, inst);
	if (err) {
out_free_inst:
		inst->free(inst);
	}

	return err;
}

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;

	/* 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);
	return crypto_skcipher_setkey(child, key, keylen);
}

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 skcipher_instance *inst;
	struct skcipher_alg *alg;
	struct crypto_skcipher_spawn *spawn;
	u32 mask;
	int err;

	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
	if (err)
		return err;

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

	spawn = skcipher_instance_ctx(inst);

	err = crypto_grab_skcipher(spawn, skcipher_crypto_instance(inst),
				   crypto_attr_alg_name(tb[1]), 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_free_inst;

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

	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_free_inst;
	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_free_inst;

	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.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) {
err_free_inst:
		crypto_rfc3686_free(inst);
	}
	return err;
}

static struct crypto_template crypto_ctr_tmpls[] = {
	{
		.name = "ctr",
		.create = crypto_ctr_create,
		.module = THIS_MODULE,
	}, {
		.name = "rfc3686",
		.create = crypto_rfc3686_create,
		.module = THIS_MODULE,
	},
};

static int __init crypto_ctr_module_init(void)
{
	return crypto_register_templates(crypto_ctr_tmpls,
					 ARRAY_SIZE(crypto_ctr_tmpls));
}

static void __exit crypto_ctr_module_exit(void)
{
	crypto_unregister_templates(crypto_ctr_tmpls,
				    ARRAY_SIZE(crypto_ctr_tmpls));
}

subsys_initcall(crypto_ctr_module_init);
module_exit(crypto_ctr_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("CTR block cipher mode of operation");
MODULE_ALIAS_CRYPTO("rfc3686");
MODULE_ALIAS_CRYPTO("ctr");
MODULE_IMPORT_NS(CRYPTO_INTERNAL);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
23e353c8 JL	2	/*
	3	* CTR: Counter mode
	4	*
	5	* (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
23e353c8 JL	6	*/
	7
	8	#include <crypto/algapi.h>
5311f248	9	#include <crypto/ctr.h>
0eb76ba2	10	#include <crypto/internal/cipher.h>
69d3150c	11	#include <crypto/internal/skcipher.h>
23e353c8 JL	12	#include <linux/err.h>
	13	#include <linux/init.h>
	14	#include <linux/kernel.h>
	15	#include <linux/module.h>
23e353c8 JL	16	#include <linux/slab.h>
23e353c8 JL	17
5311f248	18	struct crypto_rfc3686_ctx {
b2b39c2f	19	struct crypto_skcipher *child;
5311f248	20	u8 nonce[CTR_RFC3686_NONCE_SIZE];
23e353c8 JL	21	};
23e353c8 JL	22
69d3150c JK	23	struct crypto_rfc3686_req_ctx {
69d3150c JK	24	u8 iv[CTR_RFC3686_BLOCK_SIZE];
b2b39c2f	25	struct skcipher_request subreq CRYPTO_MINALIGN_ATTR;
69d3150c JK	26	};
69d3150c JK	27
11f14630	28	static void crypto_ctr_crypt_final(struct skcipher_walk *walk,
5311f248	29	struct crypto_cipher *tfm)
0971eb0d HX	30	{
0971eb0d HX	31	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248 HX	32	unsigned long alignmask = crypto_cipher_alignmask(tfm);
5311f248 HX	33	u8 *ctrblk = walk->iv;
6650c4de	34	u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
5311f248	35	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
0971eb0d HX	36	u8 *src = walk->src.virt.addr;
	37	u8 *dst = walk->dst.virt.addr;
	38	unsigned int nbytes = walk->nbytes;
	39
	40	crypto_cipher_encrypt_one(tfm, keystream, ctrblk);
45fe93df	41	crypto_xor_cpy(dst, keystream, src, nbytes);
5311f248 HX	42
5311f248 HX	43	crypto_inc(ctrblk, bsize);
0971eb0d HX	44	}
0971eb0d HX	45
11f14630	46	static int crypto_ctr_crypt_segment(struct skcipher_walk *walk,
5311f248	47	struct crypto_cipher *tfm)
23e353c8 JL	48	{
	49	void (fn)(struct crypto_tfm , u8 , const u8 ) =
	50	crypto_cipher_alg(tfm)->cia_encrypt;
	51	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248	52	u8 *ctrblk = walk->iv;
23e353c8 JL	53	u8 *src = walk->src.virt.addr;
	54	u8 *dst = walk->dst.virt.addr;
	55	unsigned int nbytes = walk->nbytes;
	56
	57	do {
	58	/* create keystream */
0971eb0d HX	59	fn(crypto_cipher_tfm(tfm), dst, ctrblk);
0971eb0d HX	60	crypto_xor(dst, src, bsize);
23e353c8 JL	61
23e353c8 JL	62	/* increment counter in counterblock */
5311f248	63	crypto_inc(ctrblk, bsize);
23e353c8	64
23e353c8 JL	65	src += bsize;
23e353c8 JL	66	dst += bsize;
0971eb0d	67	} while ((nbytes -= bsize) >= bsize);
23e353c8	68
0971eb0d	69	return nbytes;
23e353c8 JL	70	}
23e353c8 JL	71
11f14630	72	static int crypto_ctr_crypt_inplace(struct skcipher_walk *walk,
5311f248	73	struct crypto_cipher *tfm)
23e353c8 JL	74	{
	75	void (fn)(struct crypto_tfm , u8 , const u8 ) =
	76	crypto_cipher_alg(tfm)->cia_encrypt;
	77	unsigned int bsize = crypto_cipher_blocksize(tfm);
5311f248	78	unsigned long alignmask = crypto_cipher_alignmask(tfm);
23e353c8	79	unsigned int nbytes = walk->nbytes;
5311f248	80	u8 *ctrblk = walk->iv;
23e353c8	81	u8 *src = walk->src.virt.addr;
6650c4de	82	u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
5311f248	83	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
23e353c8 JL	84
	85	do {
	86	/* create keystream */
	87	fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
0971eb0d	88	crypto_xor(src, keystream, bsize);
23e353c8 JL	89
23e353c8 JL	90	/* increment counter in counterblock */
5311f248	91	crypto_inc(ctrblk, bsize);
23e353c8	92
23e353c8	93	src += bsize;
0971eb0d	94	} while ((nbytes -= bsize) >= bsize);
23e353c8	95
0971eb0d	96	return nbytes;
23e353c8 JL	97	}
23e353c8 JL	98
11f14630	99	static int crypto_ctr_crypt(struct skcipher_request *req)
23e353c8	100	{
11f14630 EB	101	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	102	struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
	103	const unsigned int bsize = crypto_cipher_blocksize(cipher);
	104	struct skcipher_walk walk;
	105	unsigned int nbytes;
23e353c8 JL	106	int err;
23e353c8 JL	107
11f14630	108	err = skcipher_walk_virt(&walk, req, false);
23e353c8	109
0971eb0d	110	while (walk.nbytes >= bsize) {
23e353c8	111	if (walk.src.virt.addr == walk.dst.virt.addr)
11f14630	112	nbytes = crypto_ctr_crypt_inplace(&walk, cipher);
23e353c8	113	else
11f14630	114	nbytes = crypto_ctr_crypt_segment(&walk, cipher);
23e353c8	115
11f14630	116	err = skcipher_walk_done(&walk, nbytes);
23e353c8	117	}
0971eb0d HX	118
0971eb0d HX	119	if (walk.nbytes) {
11f14630 EB	120	crypto_ctr_crypt_final(&walk, cipher);
11f14630 EB	121	err = skcipher_walk_done(&walk, 0);
0971eb0d HX	122	}
0971eb0d HX	123
23e353c8 JL	124	return err;
	125	}
	126
11f14630	127	static int crypto_ctr_create(struct crypto_template tmpl, struct rtattr *tb)
23e353c8	128	{
11f14630	129	struct skcipher_instance *inst;
23e353c8	130	struct crypto_alg *alg;
23e353c8 JL	131	int err;
23e353c8 JL	132
b3c16bfc	133	inst = skcipher_alloc_instance_simple(tmpl, tb);
11f14630 EB	134	if (IS_ERR(inst))
11f14630 EB	135	return PTR_ERR(inst);
23e353c8	136
b3c16bfc HX	137	alg = skcipher_ialg_simple(inst);
b3c16bfc HX	138
5311f248	139	/* Block size must be >= 4 bytes. */
23e353c8	140	err = -EINVAL;
5311f248	141	if (alg->cra_blocksize < 4)
11f14630	142	goto out_free_inst;
23e353c8	143
3f8214ea	144	/* If this is false we'd fail the alignment of crypto_inc. */
5311f248	145	if (alg->cra_blocksize % 4)
11f14630	146	goto out_free_inst;
23e353c8	147
11f14630 EB	148	/* CTR mode is a stream cipher. */
11f14630 EB	149	inst->alg.base.cra_blocksize = 1;
23e353c8	150
11f14630 EB	151	/*
	152	* To simplify the implementation, configure the skcipher walk to only
	153	* give a partial block at the very end, never earlier.
	154	*/
	155	inst->alg.chunksize = alg->cra_blocksize;
23e353c8	156
11f14630 EB	157	inst->alg.encrypt = crypto_ctr_crypt;
11f14630 EB	158	inst->alg.decrypt = crypto_ctr_crypt;
23e353c8	159
11f14630	160	err = skcipher_register_instance(tmpl, inst);
b3c16bfc	161	if (err) {
11f14630	162	out_free_inst:
b3c16bfc HX	163	inst->free(inst);
	164	}
	165
11f14630	166	return err;
23e353c8 JL	167	}
23e353c8 JL	168
b2b39c2f	169	static int crypto_rfc3686_setkey(struct crypto_skcipher *parent,
69d3150c	170	const u8 *key, unsigned int keylen)
5311f248	171	{
b2b39c2f HX	172	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
b2b39c2f HX	173	struct crypto_skcipher *child = ctx->child;
5311f248 HX	174
	175	/* the nonce is stored in bytes at end of key */
	176	if (keylen < CTR_RFC3686_NONCE_SIZE)
	177	return -EINVAL;
	178
	179	memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
	180	CTR_RFC3686_NONCE_SIZE);
	181
	182	keylen -= CTR_RFC3686_NONCE_SIZE;
	183
b2b39c2f HX	184	crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	185	crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
	186	CRYPTO_TFM_REQ_MASK);
af5034e8	187	return crypto_skcipher_setkey(child, key, keylen);
5311f248 HX	188	}
5311f248 HX	189
b2b39c2f	190	static int crypto_rfc3686_crypt(struct skcipher_request *req)
5311f248	191	{
b2b39c2f HX	192	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	193	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	194	struct crypto_skcipher *child = ctx->child;
	195	unsigned long align = crypto_skcipher_alignmask(tfm);
69d3150c	196	struct crypto_rfc3686_req_ctx *rctx =
b2b39c2f HX	197	(void )PTR_ALIGN((u8 )skcipher_request_ctx(req), align + 1);
b2b39c2f HX	198	struct skcipher_request *subreq = &rctx->subreq;
69d3150c	199	u8 *iv = rctx->iv;
5311f248 HX	200
	201	/* set up counter block */
	202	memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
b2b39c2f	203	memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
5311f248 HX	204
	205	/* initialize counter portion of counter block */
	206	(__be32 )(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
	207	cpu_to_be32(1);
	208
b2b39c2f HX	209	skcipher_request_set_tfm(subreq, child);
	210	skcipher_request_set_callback(subreq, req->base.flags,
	211	req->base.complete, req->base.data);
	212	skcipher_request_set_crypt(subreq, req->src, req->dst,
	213	req->cryptlen, iv);
5311f248	214
b2b39c2f	215	return crypto_skcipher_encrypt(subreq);
5311f248 HX	216	}
5311f248 HX	217
b2b39c2f	218	static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm)
5311f248	219	{
b2b39c2f HX	220	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
	221	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
	222	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	223	struct crypto_skcipher *cipher;
69d3150c	224	unsigned long align;
b2b39c2f	225	unsigned int reqsize;
5311f248	226
60425a8b	227	cipher = crypto_spawn_skcipher(spawn);
5311f248 HX	228	if (IS_ERR(cipher))
	229	return PTR_ERR(cipher);
	230
	231	ctx->child = cipher;
	232
b2b39c2f	233	align = crypto_skcipher_alignmask(tfm);
69d3150c	234	align &= ~(crypto_tfm_ctx_alignment() - 1);
b2b39c2f HX	235	reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) +
	236	crypto_skcipher_reqsize(cipher);
	237	crypto_skcipher_set_reqsize(tfm, reqsize);
69d3150c	238
5311f248 HX	239	return 0;
	240	}
	241
b2b39c2f	242	static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm)
5311f248	243	{
b2b39c2f HX	244	struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
	245
	246	crypto_free_skcipher(ctx->child);
	247	}
5311f248	248
b2b39c2f HX	249	static void crypto_rfc3686_free(struct skcipher_instance *inst)
	250	{
	251	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
	252
	253	crypto_drop_skcipher(spawn);
	254	kfree(inst);
5311f248 HX	255	}
5311f248 HX	256
b2b39c2f HX	257	static int crypto_rfc3686_create(struct crypto_template *tmpl,
b2b39c2f HX	258	struct rtattr **tb)
5311f248	259	{
b2b39c2f HX	260	struct skcipher_instance *inst;
b2b39c2f HX	261	struct skcipher_alg *alg;
69d3150c	262	struct crypto_skcipher_spawn *spawn;
d2c2a85c	263	u32 mask;
5311f248 HX	264	int err;
5311f248 HX	265
7bcb2c99 EB	266	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
	267	if (err)
	268	return err;
69d3150c	269
69d3150c JK	270	inst = kzalloc(sizeof(inst) + sizeof(spawn), GFP_KERNEL);
69d3150c JK	271	if (!inst)
b2b39c2f	272	return -ENOMEM;
69d3150c	273
b2b39c2f	274	spawn = skcipher_instance_ctx(inst);
69d3150c	275
b9f76ddd	276	err = crypto_grab_skcipher(spawn, skcipher_crypto_instance(inst),
a108dfcf	277	crypto_attr_alg_name(tb[1]), 0, mask);
69d3150c JK	278	if (err)
	279	goto err_free_inst;
	280
b2b39c2f	281	alg = crypto_spawn_skcipher_alg(spawn);
69d3150c	282
5311f248 HX	283	/* We only support 16-byte blocks. */
5311f248 HX	284	err = -EINVAL;
b2b39c2f	285	if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
a108dfcf	286	goto err_free_inst;
5311f248 HX	287
5311f248 HX	288	/* Not a stream cipher? */
b2b39c2f	289	if (alg->base.cra_blocksize != 1)
a108dfcf	290	goto err_free_inst;
5311f248	291
69d3150c	292	err = -ENAMETOOLONG;
b2b39c2f HX	293	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
b2b39c2f HX	294	"rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
a108dfcf	295	goto err_free_inst;
b2b39c2f HX	296	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
	297	"rfc3686(%s)", alg->base.cra_driver_name) >=
	298	CRYPTO_MAX_ALG_NAME)
a108dfcf	299	goto err_free_inst;
5311f248	300
b2b39c2f HX	301	inst->alg.base.cra_priority = alg->base.cra_priority;
	302	inst->alg.base.cra_blocksize = 1;
	303	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
5311f248	304
b2b39c2f HX	305	inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
	306	inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
	307	inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
	308	CTR_RFC3686_NONCE_SIZE;
	309	inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
	310	CTR_RFC3686_NONCE_SIZE;
5311f248	311
b2b39c2f HX	312	inst->alg.setkey = crypto_rfc3686_setkey;
	313	inst->alg.encrypt = crypto_rfc3686_crypt;
	314	inst->alg.decrypt = crypto_rfc3686_crypt;
69d3150c	315
b2b39c2f	316	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
0a270321	317
b2b39c2f HX	318	inst->alg.init = crypto_rfc3686_init_tfm;
b2b39c2f HX	319	inst->alg.exit = crypto_rfc3686_exit_tfm;
5311f248	320
b2b39c2f	321	inst->free = crypto_rfc3686_free;
5311f248	322
b2b39c2f	323	err = skcipher_register_instance(tmpl, inst);
a108dfcf	324	if (err) {
69d3150c	325	err_free_inst:
a108dfcf EB	326	crypto_rfc3686_free(inst);
	327	}
	328	return err;
5311f248 HX	329	}
5311f248 HX	330
9f8ef365 XW	331	static struct crypto_template crypto_ctr_tmpls[] = {
	332	{
	333	.name = "ctr",
	334	.create = crypto_ctr_create,
	335	.module = THIS_MODULE,
	336	}, {
	337	.name = "rfc3686",
	338	.create = crypto_rfc3686_create,
	339	.module = THIS_MODULE,
	340	},
5311f248 HX	341	};
5311f248 HX	342
23e353c8 JL	343	static int __init crypto_ctr_module_init(void)
23e353c8 JL	344	{
9f8ef365 XW	345	return crypto_register_templates(crypto_ctr_tmpls,
9f8ef365 XW	346	ARRAY_SIZE(crypto_ctr_tmpls));
23e353c8 JL	347	}
	348
	349	static void __exit crypto_ctr_module_exit(void)
	350	{
9f8ef365 XW	351	crypto_unregister_templates(crypto_ctr_tmpls,
9f8ef365 XW	352	ARRAY_SIZE(crypto_ctr_tmpls));
23e353c8 JL	353	}
23e353c8 JL	354
c4741b23	355	subsys_initcall(crypto_ctr_module_init);
23e353c8 JL	356	module_exit(crypto_ctr_module_exit);
	357
	358	MODULE_LICENSE("GPL");
11f14630	359	MODULE_DESCRIPTION("CTR block cipher mode of operation");
5d26a105	360	MODULE_ALIAS_CRYPTO("rfc3686");
4943ba16	361	MODULE_ALIAS_CRYPTO("ctr");
0eb76ba2	362	MODULE_IMPORT_NS(CRYPTO_INTERNAL);