mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-23 11:18:54 +00:00
105 lines
3.3 KiB
C
105 lines
3.3 KiB
C
|
|
/*
|
|
* rc4.c
|
|
*
|
|
* Copyright (c) 1996-2000 Whistle Communications, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* Subject to the following obligations and disclaimer of warranty, use and
|
|
* redistribution of this software, in source or object code forms, with or
|
|
* without modifications are expressly permitted by Whistle Communications;
|
|
* provided, however, that:
|
|
* 1. Any and all reproductions of the source or object code must include the
|
|
* copyright notice above and the following disclaimer of warranties; and
|
|
* 2. No rights are granted, in any manner or form, to use Whistle
|
|
* Communications, Inc. trademarks, including the mark "WHISTLE
|
|
* COMMUNICATIONS" on advertising, endorsements, or otherwise except as
|
|
* such appears in the above copyright notice or in the software.
|
|
*
|
|
* THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
|
|
* TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
|
|
* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
|
|
* INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
|
|
* WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
|
|
* REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
|
|
* SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
|
|
* IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
|
|
* RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
|
|
* WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
|
|
* PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
* SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
* THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
|
|
* OF SUCH DAMAGE.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
#include <crypto/rc4/rc4.h>
|
|
|
|
static __inline void
|
|
swap_bytes(u_char *a, u_char *b)
|
|
{
|
|
u_char temp;
|
|
|
|
temp = *a;
|
|
*a = *b;
|
|
*b = temp;
|
|
}
|
|
|
|
/*
|
|
* Initialize an RC4 state buffer using the supplied key,
|
|
* which can have arbitrary length.
|
|
*/
|
|
void
|
|
rc4_init(struct rc4_state *const state, const u_char *key, int keylen)
|
|
{
|
|
u_char j;
|
|
int i;
|
|
|
|
/* Initialize state with identity permutation */
|
|
for (i = 0; i < 256; i++)
|
|
state->perm[i] = (u_char)i;
|
|
state->index1 = 0;
|
|
state->index2 = 0;
|
|
|
|
/* Randomize the permutation using key data */
|
|
for (j = i = 0; i < 256; i++) {
|
|
j += state->perm[i] + key[i % keylen];
|
|
swap_bytes(&state->perm[i], &state->perm[j]);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Encrypt some data using the supplied RC4 state buffer.
|
|
* The input and output buffers may be the same buffer.
|
|
* Since RC4 is a stream cypher, this function is used
|
|
* for both encryption and decryption.
|
|
*/
|
|
void
|
|
rc4_crypt(struct rc4_state *const state,
|
|
const u_char *inbuf, u_char *outbuf, int buflen)
|
|
{
|
|
int i;
|
|
u_char j;
|
|
|
|
for (i = 0; i < buflen; i++) {
|
|
|
|
/* Update modification indicies */
|
|
state->index1++;
|
|
state->index2 += state->perm[state->index1];
|
|
|
|
/* Modify permutation */
|
|
swap_bytes(&state->perm[state->index1],
|
|
&state->perm[state->index2]);
|
|
|
|
/* Encrypt/decrypt next byte */
|
|
j = state->perm[state->index1] + state->perm[state->index2];
|
|
outbuf[i] = inbuf[i] ^ state->perm[j];
|
|
}
|
|
}
|
|
|