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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/crypto/arc4.c
26131 views
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// SPDX-License-Identifier: GPL-2.0-or-later

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/*

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 * Cryptographic API

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 *

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 * ARC4 Cipher Algorithm

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 *

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 * Jon Oberheide <[email protected]>

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 */

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#include <crypto/arc4.h>

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#include <crypto/internal/skcipher.h>

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#include <linux/init.h>

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#include <linux/kernel.h>

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#include <linux/module.h>

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#include <linux/sched.h>

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#define ARC4_ALIGN __alignof__(struct arc4_ctx)

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static int crypto_arc4_setkey(struct crypto_lskcipher *tfm, const u8 *in_key,

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			      unsigned int key_len)

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{

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	struct arc4_ctx *ctx = crypto_lskcipher_ctx(tfm);

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	return arc4_setkey(ctx, in_key, key_len);

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}

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static int crypto_arc4_crypt(struct crypto_lskcipher *tfm, const u8 *src,

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			     u8 *dst, unsigned nbytes, u8 *siv, u32 flags)

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{

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	struct arc4_ctx *ctx = crypto_lskcipher_ctx(tfm);

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	if (!(flags & CRYPTO_LSKCIPHER_FLAG_CONT))

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		memcpy(siv, ctx, sizeof(*ctx));

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	ctx = (struct arc4_ctx *)siv;

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	arc4_crypt(ctx, dst, src, nbytes);

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	return 0;

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}

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static int crypto_arc4_init(struct crypto_lskcipher *tfm)

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{

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	pr_warn_ratelimited("\"%s\" (%ld) uses obsolete ecb(arc4) skcipher\n",

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			    current->comm, (unsigned long)current->pid);

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	return 0;

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}

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static struct lskcipher_alg arc4_alg = {

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	.co.base.cra_name		=	"arc4",

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	.co.base.cra_driver_name	=	"arc4-generic",

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	.co.base.cra_priority		=	100,

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	.co.base.cra_blocksize		=	ARC4_BLOCK_SIZE,

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	.co.base.cra_ctxsize		=	sizeof(struct arc4_ctx),

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	.co.base.cra_alignmask		=	ARC4_ALIGN - 1,

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	.co.base.cra_module		=	THIS_MODULE,

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	.co.min_keysize			=	ARC4_MIN_KEY_SIZE,

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	.co.max_keysize			=	ARC4_MAX_KEY_SIZE,

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	.co.statesize			=	sizeof(struct arc4_ctx),

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	.setkey				=	crypto_arc4_setkey,

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	.encrypt			=	crypto_arc4_crypt,

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	.decrypt			=	crypto_arc4_crypt,

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	.init				=	crypto_arc4_init,

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};

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static int __init arc4_init(void)

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{

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	return crypto_register_lskcipher(&arc4_alg);

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}

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static void __exit arc4_exit(void)

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{

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	crypto_unregister_lskcipher(&arc4_alg);

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}

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module_init(arc4_init);

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module_exit(arc4_exit);

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MODULE_LICENSE("GPL");

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MODULE_DESCRIPTION("ARC4 Cipher Algorithm");

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MODULE_AUTHOR("Jon Oberheide <[email protected]>");

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MODULE_ALIAS_CRYPTO("ecb(arc4)");

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