| /* |
| * Copyright (c) 1996, 2003 VIA Networking Technologies, Inc. |
| * All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * File: rc4.c |
| * |
| * Purpose: |
| * |
| * Functions: |
| * |
| * Revision History: |
| * |
| * Author: Kyle Hsu |
| * |
| * Date: Sep 4, 2002 |
| * |
| */ |
| |
| #include "rc4.h" |
| |
| void rc4_init(PRC4Ext pRC4, PBYTE pbyKey, UINT cbKey_len) |
| { |
| UINT ust1, ust2; |
| UINT keyindex; |
| UINT stateindex; |
| PBYTE pbyst; |
| UINT idx; |
| |
| pbyst = pRC4->abystate; |
| pRC4->ux = 0; |
| pRC4->uy = 0; |
| for (idx = 0; idx < 256; idx++) |
| pbyst[idx] = (BYTE)idx; |
| keyindex = 0; |
| stateindex = 0; |
| for (idx = 0; idx < 256; idx++) { |
| ust1 = pbyst[idx]; |
| stateindex = (stateindex + pbyKey[keyindex] + ust1) & 0xff; |
| ust2 = pbyst[stateindex]; |
| pbyst[stateindex] = (BYTE)ust1; |
| pbyst[idx] = (BYTE)ust2; |
| if (++keyindex >= cbKey_len) |
| keyindex = 0; |
| } |
| } |
| |
| UINT rc4_byte(PRC4Ext pRC4) |
| { |
| UINT ux; |
| UINT uy; |
| UINT ustx, usty; |
| PBYTE pbyst; |
| |
| pbyst = pRC4->abystate; |
| ux = (pRC4->ux + 1) & 0xff; |
| ustx = pbyst[ux]; |
| uy = (ustx + pRC4->uy) & 0xff; |
| usty = pbyst[uy]; |
| pRC4->ux = ux; |
| pRC4->uy = uy; |
| pbyst[uy] = (BYTE)ustx; |
| pbyst[ux] = (BYTE)usty; |
| |
| return pbyst[(ustx + usty) & 0xff]; |
| } |
| |
| void rc4_encrypt(PRC4Ext pRC4, PBYTE pbyDest, |
| PBYTE pbySrc, UINT cbData_len) |
| { |
| UINT ii; |
| for (ii = 0; ii < cbData_len; ii++) |
| pbyDest[ii] = (BYTE)(pbySrc[ii] ^ rc4_byte(pRC4)); |
| } |