2 Copyright (C) 2003-2008 Dominik Reichl <dominik.reichl@t-online.de>
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 void CArcFour::setKey(quint8* key, uint length){
23 RawKeyLength = length;
26 void CArcFour::encrypt(const quint8* src, quint8* dst, uint length){
30 for(w = 0; w < 256; ++w)
31 S[w] = static_cast<quint8>(w); // Fill linearly
33 const quint8 btBufDep = static_cast<quint8>((length & 0xFF) << 1);
35 quint8 i = 0, j = 0, t;
37 for(w = 0; w < 256; ++w) // Key setup
39 j += S[w] + RawKey[k] + btBufDep;
41 t = S[i]; S[i] = S[j]; S[j] = t; // Swap entries
44 if(k == RawKeyLength) k = 0;
48 for(w = 0; w < length; ++w) // Encrypt PT
53 t = S[i]; S[i] = S[j]; S[j] = t; // Swap entries
55 t = S[i] + S[j]; // Generate random byte
56 dst[w] = src[w] ^ S[t]; // XOR with PT