75 lines
1.1 KiB
C
75 lines
1.1 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-or-later
|
||
|
|
/*
|
||
|
|
* Cryptographic API
|
||
|
|
*
|
||
|
|
* ARC4 Cipher Algorithm
|
||
|
|
*
|
||
|
|
* Jon Oberheide <jon@oberheide.org>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include "arc4.h"
|
||
|
|
|
||
|
|
MODULE_LICENSE("GPL");
|
||
|
|
|
||
|
|
int cifs_arc4_setkey(struct arc4_ctx *ctx, const u8 *in_key, unsigned int key_len)
|
||
|
|
{
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(cifs_arc4_setkey);
|
||
|
|
|
||
|
|
void cifs_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;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(cifs_arc4_crypt);
|