/*
OrpheusMS: MapleStory Private Server based on OdinMS
Copyright (C) 2012 Aaron Weiss <aaron@deviant-core.net>
Patrick Huy <patrick.huy@frz.cc>
Matthias Butz <matze@odinms.de>
Jan Christian Meyer <vimes@odinms.de>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package net.mina;
public class MapleCustomEncryption {
private static byte rollLeft(byte in, int count) {
int tmp = (int) in & 0xFF;
tmp = tmp << (count % 8);
return (byte) ((tmp & 0xFF) | (tmp >> 8));
}
private static byte rollRight(byte in, int count) {
int tmp = (int) in & 0xFF;
tmp = (tmp << 8) >>> (count % 8);
return (byte) ((tmp & 0xFF) | (tmp >>> 8));
}
public static byte[] encryptData(byte data[]) {
for (int j = 0; j < 6; j++) {
byte remember = 0;
byte dataLength = (byte) (data.length & 0xFF);
if (j % 2 == 0) {
for (int i = 0; i < data.length; i++) {
byte cur = data[i];
cur = rollLeft(cur, 3);
cur += dataLength;
cur ^= remember;
remember = cur;
cur = rollRight(cur, (int) dataLength & 0xFF);
cur = ((byte) ((~cur) & 0xFF));
cur += 0x48;
dataLength--;
data[i] = cur;
}
} else {
for (int i = data.length - 1; i >= 0; i--) {
byte cur = data[i];
cur = rollLeft(cur, 4);
cur += dataLength;
cur ^= remember;
remember = cur;
cur ^= 0x13;
cur = rollRight(cur, 3);
dataLength--;
data[i] = cur;
}
}
}
return data;
}
public static byte[] decryptData(byte data[]) {
for (int j = 1; j <= 6; j++) {
byte remember = 0;
byte dataLength = (byte) (data.length & 0xFF);
byte nextRemember = 0;
if (j % 2 == 0) {
for (int i = 0; i < data.length; i++) {
byte cur = data[i];
cur -= 0x48;
cur = ((byte) ((~cur) & 0xFF));
cur = rollLeft(cur, (int) dataLength & 0xFF);
nextRemember = cur;
cur ^= remember;
remember = nextRemember;
cur -= dataLength;
cur = rollRight(cur, 3);
data[i] = cur;
dataLength--;
}
} else {
for (int i = data.length - 1; i >= 0; i--) {
byte cur = data[i];
cur = rollLeft(cur, 3);
cur ^= 0x13;
nextRemember = cur;
cur ^= remember;
remember = nextRemember;
cur -= dataLength;
cur = rollRight(cur, 4);
data[i] = cur;
dataLength--;
}
}
}
return data;
}
}