[linux-2.6-block.git] / crypto / arc4.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Cryptographic API
 *
 * ARC4 Cipher Algorithm
 *
 * Jon Oberheide <jon@oberheide.org>
 */

#include <crypto/algapi.h>
#include <crypto/arc4.h>
#include <crypto/internal/skcipher.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>

static int crypto_arc4_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
			      unsigned int key_len)
{
	struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);

	return arc4_setkey(ctx, in_key, key_len);
}

static int crypto_arc4_crypt(struct skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct skcipher_walk walk;
	int err;

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

	while (walk.nbytes > 0) {
		arc4_crypt(ctx, walk.dst.virt.addr, walk.src.virt.addr,
			   walk.nbytes);
		err = skcipher_walk_done(&walk, 0);
	}

	return err;
}

static int crypto_arc4_init(struct crypto_skcipher *tfm)
{
	pr_warn_ratelimited("\"%s\" (%ld) uses obsolete ecb(arc4) skcipher\n",
			    current->comm, (unsigned long)current->pid);

	return 0;
}

static struct skcipher_alg arc4_alg = {
	/*
	 * For legacy reasons, this is named "ecb(arc4)", not "arc4".
	 * Nevertheless it's actually a stream cipher, not a block cipher.
	 */
	.base.cra_name		=	"ecb(arc4)",
	.base.cra_driver_name	=	"ecb(arc4)-generic",
	.base.cra_priority	=	100,
	.base.cra_blocksize	=	ARC4_BLOCK_SIZE,
	.base.cra_ctxsize	=	sizeof(struct arc4_ctx),
	.base.cra_module	=	THIS_MODULE,
	.min_keysize		=	ARC4_MIN_KEY_SIZE,
	.max_keysize		=	ARC4_MAX_KEY_SIZE,
	.setkey			=	crypto_arc4_setkey,
	.encrypt		=	crypto_arc4_crypt,
	.decrypt		=	crypto_arc4_crypt,
	.init			=	crypto_arc4_init,
};

static int __init arc4_init(void)
{
	return crypto_register_skcipher(&arc4_alg);
}

static void __exit arc4_exit(void)
{
	crypto_unregister_skcipher(&arc4_alg);
}

subsys_initcall(arc4_init);
module_exit(arc4_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>");
MODULE_ALIAS_CRYPTO("ecb(arc4)");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
cfa2b54e	2	/*
1da177e4 LT	3	* Cryptographic API
	4	*
	5	* ARC4 Cipher Algorithm
	6	*
	7	* Jon Oberheide <jon@oberheide.org>
1da177e4	8	*/
ce6dd368	9
ce6dd368	10	#include <crypto/algapi.h>
bd30cf53	11	#include <crypto/arc4.h>
426bcb50 EB	12	#include <crypto/internal/skcipher.h>
426bcb50 EB	13	#include <linux/init.h>
9ace6771	14	#include <linux/kernel.h>
426bcb50	15	#include <linux/module.h>
9ace6771	16	#include <linux/sched.h>
1da177e4	17
611a23c2 AB	18	static int crypto_arc4_setkey(struct crypto_skcipher tfm, const u8 in_key,
611a23c2 AB	19	unsigned int key_len)
426bcb50	20	{
611a23c2	21	struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);
1da177e4	22
dc51f257	23	return arc4_setkey(ctx, in_key, key_len);
ce6dd368 JK	24	}
ce6dd368 JK	25
611a23c2	26	static int crypto_arc4_crypt(struct skcipher_request *req)
ce6dd368	27	{
426bcb50 EB	28	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	29	struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);
	30	struct skcipher_walk walk;
ce6dd368 JK	31	int err;
ce6dd368 JK	32
426bcb50	33	err = skcipher_walk_virt(&walk, req, false);
ce6dd368 JK	34
ce6dd368 JK	35	while (walk.nbytes > 0) {
426bcb50 EB	36	arc4_crypt(ctx, walk.dst.virt.addr, walk.src.virt.addr,
	37	walk.nbytes);
	38	err = skcipher_walk_done(&walk, 0);
ce6dd368 JK	39	}
	40
	41	return err;
	42	}
	43
9ace6771 AB	44	static int crypto_arc4_init(struct crypto_skcipher *tfm)
	45	{
	46	pr_warn_ratelimited("\"%s\" (%ld) uses obsolete ecb(arc4) skcipher\n",
	47	current->comm, (unsigned long)current->pid);
	48
	49	return 0;
	50	}
	51
611a23c2 AB	52	static struct skcipher_alg arc4_alg = {
	53	/*
	54	* For legacy reasons, this is named "ecb(arc4)", not "arc4".
	55	* Nevertheless it's actually a stream cipher, not a block cipher.
	56	*/
426bcb50	57	.base.cra_name = "ecb(arc4)",
d6ebf528	58	.base.cra_driver_name = "ecb(arc4)-generic",
426bcb50 EB	59	.base.cra_priority = 100,
	60	.base.cra_blocksize = ARC4_BLOCK_SIZE,
	61	.base.cra_ctxsize = sizeof(struct arc4_ctx),
	62	.base.cra_module = THIS_MODULE,
	63	.min_keysize = ARC4_MIN_KEY_SIZE,
	64	.max_keysize = ARC4_MAX_KEY_SIZE,
611a23c2 AB	65	.setkey = crypto_arc4_setkey,
	66	.encrypt = crypto_arc4_crypt,
	67	.decrypt = crypto_arc4_crypt,
9ace6771	68	.init = crypto_arc4_init,
426bcb50	69	};
1da177e4 LT	70
	71	static int __init arc4_init(void)
	72	{
611a23c2	73	return crypto_register_skcipher(&arc4_alg);
1da177e4 LT	74	}
1da177e4 LT	75
1da177e4 LT	76	static void __exit arc4_exit(void)
1da177e4 LT	77	{
611a23c2	78	crypto_unregister_skcipher(&arc4_alg);
1da177e4 LT	79	}
1da177e4 LT	80
c4741b23	81	subsys_initcall(arc4_init);
1da177e4 LT	82	module_exit(arc4_exit);
	83
	84	MODULE_LICENSE("GPL");
	85	MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
	86	MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>");
611a23c2	87	MODULE_ALIAS_CRYPTO("ecb(arc4)");