/* * Copyright (C) 2004-2015 L2J Server * * This file is part of L2J Server. * * L2J Server 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 3 of the License, or * (at your option) any later version. * * L2J Server 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, see . */ package com.l2jserver.util.crypt; import java.math.BigInteger; import java.security.KeyPair; import java.security.interfaces.RSAPublicKey; import java.util.logging.Logger; /** * */ public class ScrambledKeyPair { private static Logger _log = Logger.getLogger(ScrambledKeyPair.class.getName()); public KeyPair _pair; public byte[] _scrambledModulus; public ScrambledKeyPair(KeyPair pPair) { _pair = pPair; _scrambledModulus = scrambleModulus(((RSAPublicKey) _pair.getPublic()).getModulus()); } private byte[] scrambleModulus(BigInteger modulus) { byte[] scrambledMod = modulus.toByteArray(); if ((scrambledMod.length == 0x81) && (scrambledMod[0] == 0x00)) { byte[] temp = new byte[0x80]; System.arraycopy(scrambledMod, 1, temp, 0, 0x80); scrambledMod = temp; } // step 1 : 0x4d-0x50 <-> 0x00-0x04 for (int i = 0; i < 4; i++) { byte temp = scrambledMod[0x00 + i]; scrambledMod[0x00 + i] = scrambledMod[0x4d + i]; scrambledMod[0x4d + i] = temp; } // step 2 : xor first 0x40 bytes with last 0x40 bytes for (int i = 0; i < 0x40; i++) { scrambledMod[i] = (byte) (scrambledMod[i] ^ scrambledMod[0x40 + i]); } // step 3 : xor bytes 0x0d-0x10 with bytes 0x34-0x38 for (int i = 0; i < 4; i++) { scrambledMod[0x0d + i] = (byte) (scrambledMod[0x0d + i] ^ scrambledMod[0x34 + i]); } // step 4 : xor last 0x40 bytes with first 0x40 bytes for (int i = 0; i < 0x40; i++) { scrambledMod[0x40 + i] = (byte) (scrambledMod[0x40 + i] ^ scrambledMod[i]); } _log.fine("Modulus was scrambled"); return scrambledMod; } }