2 * Copyright (c) 2004 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 /* implemented from description in draft-kaukonen-cipher-arcfour-03.txt */
43 k->state[x] = k->state[y]; \
48 RC4_set_key(RC4_KEY
*key
, const int len
, const unsigned char *data
)
52 for (i
= 0; i
< 256; i
++)
54 for (i
= 0, j
= 0; i
< 256; i
++) {
55 j
= (j
+ key
->state
[i
] + data
[i
% len
]) % 256;
62 RC4(RC4_KEY
*key
, const int len
, const unsigned char *in
, unsigned char *out
)
69 for (i
= 0; i
< len
; i
++) {
71 y
= (y
+ key
->state
[x
]) % 256;
73 t
= (key
->state
[x
] + key
->state
[y
]) % 256;
74 *out
++ = key
->state
[t
] ^ *in
++;