/*
* This file is part of FTB Launcher.
*
* Copyright © 2012-2014, FTB Launcher Contributors <https://github.com/Slowpoke101/FTBLaunch/>
* FTB Launcher is licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.ftb.util;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.util.Arrays;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import net.ftb.log.Logger;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.digest.DigestUtils;
public class CryptoUtils {
/**
* Newer implementation available if possible use {@link #decrypt(String str)}
* @param str string to decrypt
* @param key decryption key
* @return decrypted string or "" if fails
*/
@Deprecated
public static String decryptLegacy (String str, byte[] key) {
BigInteger in = new BigInteger(str, 16).xor(new BigInteger(1, key));
try {
return new String(in.toByteArray(), "utf8");
} catch (UnsupportedEncodingException e) {
return "";
} catch (NumberFormatException e) {
Logger.logError("Error occurred during legacy decryption");
return "";
}
}
/**
* Newer implementation available if possible use {@link #encrypt(String str)}
* @param str string to decrypt
* @param key decryption key
* @return decrypted string or "" if fails
*/
@Deprecated
public static String encryptLegacy (String str, byte[] key) {
BigInteger str2;
try {
str2 = new BigInteger(str.getBytes("utf8")).xor(new BigInteger(1, key));
} catch (UnsupportedEncodingException e) {
return "";
}
return String.format("%040x", str2);
}
/**
* Method to AES decrypt string if fails, will attempt to use {@link #decryptLegacy(String str, byte[] key)}
* @param str string to decrypt
* @return decrypted string or "" if legacy fails
*/
public static String decrypt (String str) {
byte[] keyMac = OSUtils.getMacAddress();
byte[] keyHardware = OSUtils.getHardwareID();
String s;
try {
Cipher aes = Cipher.getInstance("AES");
if (keyHardware != null && keyHardware.length > 0) {
try {
aes.init(Cipher.DECRYPT_MODE, new SecretKeySpec(pad(keyHardware), "AES"));
s = new String(aes.doFinal(Base64.decodeBase64(str)), "utf8");
if (s.startsWith("FDT:") && s.length() > 4) {
return s.split(":", 2)[1];// it was decrypted with HW UUID
}
} catch (Exception e) {
Logger.logDebug("foo", e);
}
}
// did not open, try again with old mac based key
aes.init(Cipher.DECRYPT_MODE, new SecretKeySpec(pad(keyMac), "AES"));
s = new String(aes.doFinal(Base64.decodeBase64(str)), "utf8");
if (s.startsWith("FDT:") && s.length() > 4) {
return s.split(":", 2)[1];//we don't want the decryption test
} else {
return decryptLegacy(str, keyMac);
}
} catch (Exception e) {
Logger.logError("Error Decrypting information, attempting legacy decryption", e);
return decryptLegacy(str, keyMac);
}
}
/**
* Method to AES encrypt string if fails, will attempt to use {@link #encryptLegacy(String str, byte[] key)}
* @param str string to encrypt
* @return encrypted string or "" if legacy fails
*/
public static String encrypt (String str) {
byte[] keyMac = OSUtils.getMacAddress();
byte[] keyHardware = OSUtils.getHardwareID();
try {
Cipher aes = Cipher.getInstance("AES");
if (keyHardware != null && keyHardware.length > 0) {
aes.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(pad(keyHardware), "AES"));
return Base64.encodeBase64String(aes.doFinal(("FDT:" + str).getBytes("utf8")));
}
aes.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(pad(keyMac), "AES"));
return Base64.encodeBase64String(aes.doFinal(("FDT:" + str).getBytes("utf8")));
} catch (Exception e) {
Logger.logError("Error Encrypting information, reverting to legacy format", e);
return encryptLegacy(str, keyMac);
}
}
/**
* method to pad AES keys by using the sha1Hex hash on them
* @param key key to pad
* @return padded key
*/
public static byte[] pad (byte[] key) {
try {
return Arrays.copyOf(DigestUtils.sha1Hex(key).getBytes("utf8"), 16);
} catch (UnsupportedEncodingException e) {
Logger.logError("error encoding padded key!", e);
return Arrays.copyOf(DigestUtils.sha1Hex(key).getBytes(), 16);
}
}
}