diff options
Diffstat (limited to 'crypto/arc4.c')
| -rw-r--r-- | crypto/arc4.c | 124 | 
1 files changed, 94 insertions, 30 deletions
diff --git a/crypto/arc4.c b/crypto/arc4.c index 8be47e13a9e..5a772c3657d 100644 --- a/crypto/arc4.c +++ b/crypto/arc4.c @@ -1,4 +1,4 @@ -/*  +/*   * Cryptographic API   *   * ARC4 Cipher Algorithm @@ -11,17 +11,19 @@   * (at your option) any later version.   *   */ +  #include <linux/module.h>  #include <linux/init.h>  #include <linux/crypto.h> +#include <crypto/algapi.h>  #define ARC4_MIN_KEY_SIZE	1  #define ARC4_MAX_KEY_SIZE	256  #define ARC4_BLOCK_SIZE		1  struct arc4_ctx { -	u8 S[256]; -	u8 x, y; +	u32 S[256]; +	u32 x, y;  };  static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key, @@ -33,67 +35,129 @@ static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key,  	ctx->x = 1;  	ctx->y = 0; -	for(i = 0; i < 256; i++) +	for (i = 0; i < 256; i++)  		ctx->S[i] = i; -	for(i = 0; i < 256; i++) -	{ -		u8 a = ctx->S[i]; +	for (i = 0; i < 256; i++) { +		u32 a = ctx->S[i];  		j = (j + in_key[k] + a) & 0xff;  		ctx->S[i] = ctx->S[j];  		ctx->S[j] = a; -		if(++k >= key_len) +		if (++k >= key_len)  			k = 0;  	}  	return 0;  } -static void arc4_crypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) +static void arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in, +		       unsigned int len)  { -	struct arc4_ctx *ctx = crypto_tfm_ctx(tfm); +	u32 *const S = ctx->S; +	u32 x, y, a, b; +	u32 ty, ta, tb; + +	if (len == 0) +		return; -	u8 *const S = ctx->S; -	u8 x = ctx->x; -	u8 y = ctx->y; -	u8 a, b; +	x = ctx->x; +	y = ctx->y;  	a = S[x];  	y = (y + a) & 0xff;  	b = S[y]; -	S[x] = b; -	S[y] = a; -	x = (x + 1) & 0xff; -	*out++ = *in ^ S[(a + b) & 0xff]; + +	do { +		S[y] = a; +		a = (a + b) & 0xff; +		S[x] = b; +		x = (x + 1) & 0xff; +		ta = S[x]; +		ty = (y + ta) & 0xff; +		tb = S[ty]; +		*out++ = *in++ ^ S[a]; +		if (--len == 0) +			break; +		y = ty; +		a = ta; +		b = tb; +	} while (true);  	ctx->x = x;  	ctx->y = y;  } -static struct crypto_alg arc4_alg = { +static void arc4_crypt_one(struct crypto_tfm *tfm, u8 *out, const u8 *in) +{ +	arc4_crypt(crypto_tfm_ctx(tfm), out, in, 1); +} + +static int ecb_arc4_crypt(struct blkcipher_desc *desc, struct scatterlist *dst, +			  struct scatterlist *src, unsigned int nbytes) +{ +	struct arc4_ctx *ctx = crypto_blkcipher_ctx(desc->tfm); +	struct blkcipher_walk walk; +	int err; + +	blkcipher_walk_init(&walk, dst, src, nbytes); + +	err = blkcipher_walk_virt(desc, &walk); + +	while (walk.nbytes > 0) { +		u8 *wsrc = walk.src.virt.addr; +		u8 *wdst = walk.dst.virt.addr; + +		arc4_crypt(ctx, wdst, wsrc, walk.nbytes); + +		err = blkcipher_walk_done(desc, &walk, 0); +	} + +	return err; +} + +static struct crypto_alg arc4_algs[2] = { {  	.cra_name		=	"arc4",  	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,  	.cra_blocksize		=	ARC4_BLOCK_SIZE,  	.cra_ctxsize		=	sizeof(struct arc4_ctx),  	.cra_module		=	THIS_MODULE, -	.cra_list		=	LIST_HEAD_INIT(arc4_alg.cra_list), -	.cra_u			=	{ .cipher = { -	.cia_min_keysize	=	ARC4_MIN_KEY_SIZE, -	.cia_max_keysize	=	ARC4_MAX_KEY_SIZE, -	.cia_setkey	   	= 	arc4_set_key, -	.cia_encrypt	 	=	arc4_crypt, -	.cia_decrypt	  	=	arc4_crypt } } -}; +	.cra_u			=	{ +		.cipher = { +			.cia_min_keysize	=	ARC4_MIN_KEY_SIZE, +			.cia_max_keysize	=	ARC4_MAX_KEY_SIZE, +			.cia_setkey		=	arc4_set_key, +			.cia_encrypt		=	arc4_crypt_one, +			.cia_decrypt		=	arc4_crypt_one, +		}, +	}, +}, { +	.cra_name		=	"ecb(arc4)", +	.cra_priority		=	100, +	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER, +	.cra_blocksize		=	ARC4_BLOCK_SIZE, +	.cra_ctxsize		=	sizeof(struct arc4_ctx), +	.cra_alignmask		=	0, +	.cra_type		=	&crypto_blkcipher_type, +	.cra_module		=	THIS_MODULE, +	.cra_u			=	{ +		.blkcipher = { +			.min_keysize	=	ARC4_MIN_KEY_SIZE, +			.max_keysize	=	ARC4_MAX_KEY_SIZE, +			.setkey		=	arc4_set_key, +			.encrypt	=	ecb_arc4_crypt, +			.decrypt	=	ecb_arc4_crypt, +		}, +	}, +} };  static int __init arc4_init(void)  { -	return crypto_register_alg(&arc4_alg); +	return crypto_register_algs(arc4_algs, ARRAY_SIZE(arc4_algs));  } -  static void __exit arc4_exit(void)  { -	crypto_unregister_alg(&arc4_alg); +	crypto_unregister_algs(arc4_algs, ARRAY_SIZE(arc4_algs));  }  module_init(arc4_init);  | 
