/* Copyright c 2005-2012.
* Licensed under GNU LESSER General Public License, Version 3.
* http://www.gnu.org/licenses
*/
package org.beangle.security.codec;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
public class SymmetricEncryptHelper {
private Cipher enCipher;
private Cipher deCipher;
private String algorithm;
public SymmetricEncryptHelper(byte[] key) {
this(key, "DES");
}
public SymmetricEncryptHelper(byte[] key, String algorithm) {
this.algorithm = algorithm;
// DES算法要求有一个可信任的随机数源
SecureRandom sr = new SecureRandom();
try {
// 从原始密匙数据创建DESKeySpec对象
DESKeySpec dks = new DESKeySpec(key);
// 创建一个密匙工厂，然后用它把DESKeySpec转换成
// 一个SecretKey对象
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(algorithm);
SecretKey secretKey = keyFactory.generateSecret(dks);
// Cipher对象实际完成加密操作
enCipher = Cipher.getInstance(algorithm);
deCipher = Cipher.getInstance(algorithm);
// 用密匙初始化Cipher对象
enCipher.init(Cipher.ENCRYPT_MODE, secretKey, sr);
deCipher.init(Cipher.DECRYPT_MODE, secretKey, sr);
} catch (Exception e) {
throw new RuntimeException(e.getMessage());
}
}
public byte[] encypt(byte[] value) {
try {
return enCipher.doFinal(value);
} catch (Exception e) {
return new byte[0];
}
}
public byte[] decrypt(byte[] value) {
try {
return deCipher.doFinal(value);
} catch (Exception e) {
return new byte[0];
}
}
public String getAlgorithm() {
return algorithm;
}
/**
* 16进制显示数据
*
* @param value
* 字节数组
* @return
*/
public static String toHexString(byte[] value) {
String newString = "";
for (int i = 0; i < value.length; i++) {
byte b = value[i];
String str = Integer.toHexString(b);
if (str.length() > 2) {
str = str.substring(str.length() - 2);
}
if (str.length() < 2) {
str = "0" + str;
}
newString += str;
}
return newString.toUpperCase();
}
/**
* 16进制显示数据
*
* @param value
* 字节数组
* @return
*/
public static byte[] fromHexString(String value) {
byte[] rs = new byte[value.length() / 2];
for (int i = 0; i < value.length(); i += 2) {
String b = value.substring(i, i + 2);
rs[i / 2] = Integer.valueOf(b, 16).byteValue();
}
return rs;
}
public static byte[] encypt(byte[] key, byte[] value) {
return new SymmetricEncryptHelper(key).encypt(value);
}
public static byte[] decrypt(byte[] key, byte[] value) {
return new SymmetricEncryptHelper(key).decrypt(value);
}
}