3 * Copyright (C) 2006-2012 Sawtooth Consulting Ltd.
5 * This file is part of CyaSSL.
7 * CyaSSL is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * CyaSSL is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
26 #include <cyassl/ctaocrypt/arc4.h>
29 void Arc4SetKey(Arc4* arc4, const byte* key, word32 length)
32 word32 keyIndex = 0, stateIndex = 0;
37 for (i = 0; i < ARC4_STATE_SIZE; i++)
38 arc4->state[i] = (byte)i;
40 for (i = 0; i < ARC4_STATE_SIZE; i++) {
41 word32 a = arc4->state[i];
42 stateIndex += key[keyIndex] + a;
44 arc4->state[i] = arc4->state[stateIndex];
45 arc4->state[stateIndex] = (byte)a;
47 if (++keyIndex >= length)
53 static INLINE byte MakeByte(word32* x, word32* y, byte* s)
63 return s[(a+b) & 0xff];
67 void Arc4Process(Arc4* arc4, byte* out, const byte* in, word32 length)
73 *out++ = *in++ ^ MakeByte(&x, &y, arc4->state);