Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit dc51f257 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
Browse files

crypto: arc4 - refactor arc4 core code into separate library 



Refactor the core rc4 handling so we can move most users to a library
interface, permitting us to drop the cipher interface entirely in a
future patch. This is part of an effort to simplify the crypto API
and improve its robustness against incorrect use.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 192125ed

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -4229,6 +4229,7 @@ F: crypto/ 
F:	drivers/crypto/

F:	include/crypto/

F:	include/linux/crypto*

F:	lib/crypto/



CRYPTOGRAPHIC RANDOM NUMBER GENERATOR

M:	Neil Horman <nhorman@tuxdriver.com>

crypto/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -1237,9 +1237,13 @@ config CRYPTO_ANUBIS 
	  <https://www.cosic.esat.kuleuven.be/nessie/reports/>

	  <http://www.larc.usp.br/~pbarreto/AnubisPage.html>



config CRYPTO_LIB_ARC4

	tristate



config CRYPTO_ARC4

	tristate "ARC4 cipher algorithm"

	select CRYPTO_BLKCIPHER

	select CRYPTO_LIB_ARC4

	help

	  ARC4 cipher algorithm.

crypto/arc4.c

+1 −59
Original line number Diff line number Diff line
@@ -18,33 +18,12 @@ 
#include <linux/init.h>

#include <linux/module.h>



struct arc4_ctx {

	u32 S[256];

	u32 x, y;

};



static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key,

			unsigned int key_len)

{

	struct arc4_ctx *ctx = crypto_tfm_ctx(tfm);

	int i, j = 0, k = 0;



	ctx->x = 1;

	ctx->y = 0;



	for (i = 0; i < 256; i++)

		ctx->S[i] = 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)

			k = 0;

	}



	return 0;

	return arc4_setkey(ctx, in_key, key_len);

}



static int arc4_set_key_skcipher(struct crypto_skcipher *tfm, const u8 *in_key,
@@ -53,43 +32,6 @@ static int arc4_set_key_skcipher(struct crypto_skcipher *tfm, const u8 *in_key, 
	return arc4_set_key(&tfm->base, in_key, key_len);

}



static void arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in,

		       unsigned int len)

{

	u32 *const S = ctx->S;

	u32 x, y, a, b;

	u32 ty, ta, tb;



	if (len == 0)

		return;



	x = ctx->x;

	y = ctx->y;



	a = S[x];

	y = (y + a) & 0xff;

	b = S[y];



	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 void arc4_crypt_one(struct crypto_tfm *tfm, u8 *out, const u8 *in)

{

	arc4_crypt(crypto_tfm_ctx(tfm), out, in, 1);

include/crypto/arc4.h

+10 −0
Original line number Diff line number Diff line
@@ -6,8 +6,18 @@ 
#ifndef _CRYPTO_ARC4_H

#define _CRYPTO_ARC4_H



#include <linux/types.h>



#define ARC4_MIN_KEY_SIZE	1

#define ARC4_MAX_KEY_SIZE	256

#define ARC4_BLOCK_SIZE		1



struct arc4_ctx {

	u32 S[256];

	u32 x, y;

};



int arc4_setkey(struct arc4_ctx *ctx, const u8 *in_key, unsigned int key_len);

void arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in, unsigned int len);



#endif /* _CRYPTO_ARC4_H */

lib/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -102,7 +102,7 @@ endif 
obj-$(CONFIG_DEBUG_INFO_REDUCED) += debug_info.o

CFLAGS_debug_info.o += $(call cc-option, -femit-struct-debug-detailed=any)



obj-y += math/

obj-y += math/ crypto/



obj-$(CONFIG_GENERIC_IOMAP) += iomap.o

obj-$(CONFIG_GENERIC_PCI_IOMAP) += pci_iomap.o