DesUtil.java

package com.realmo.utils;

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;

/**
 * DES加密解密
 */
public class DesUtil {

 private static final String ALGORITHM = "DES";
 private static final String KEY = "12345678";
 public static final String LOCAL_KEY = "12344321";//本地加密秘钥

 /**
 * 初始化生成密钥
 */
 private static String initKey(String seed) {
 try {
 SecureRandom random = null;
 if (seed != null) {
 random = new SecureRandom(seed.getBytes());
 } else {
 random = new SecureRandom();
 }
 // 初始化密钥生成器
 KeyGenerator keyGenerator = KeyGenerator.getInstance(ALGORITHM);
 keyGenerator.init(random);
 SecretKey key = keyGenerator.generateKey();
 // 获取密钥二进制字节数组
 byte[] keyBytes = key.getEncoded();
 // 转换为Base64编码内容
 return Base64Util.encodeByte(keyBytes);
 } catch (NoSuchAlgorithmException e) {
 e.printStackTrace();
 }
 return null;
 }

 /**
 * 加密
 */
 public static String encrypt(String src) {
 return encrypt(src, KEY);
 }

 /**
 * 加密 传入秘钥
 */
 public static String encrypt(String src, String keyString) {
 try {
 // 获取密钥 - Key应该是Base64编码后的密钥的字符串
 // 把字符串转换为密钥对象
 Key key = getKey(keyString);
 IvParameterSpec zeroIv = new IvParameterSpec(KEY.getBytes("UTF-8"));
 Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
 cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
 byte[] bytes = cipher.doFinal(src.getBytes("UTF-8"));
 return Base64Util.encodeByte(bytes);
 } catch (Exception e) {
 e.printStackTrace();
 return e.getMessage();
 }
 }

 /**
 * 解密
 */
 public static String decrypt(String dest){
 try {
 return decrypt(dest, KEY);
 } catch (Exception e) {
 e.printStackTrace();
 return dest.trim();
 }
 }

 public static String decrypt(String dest, String keyString) throws Exception {
 Key key = getKey(keyString);
 IvParameterSpec zeroIv = new IvParameterSpec(KEY.getBytes("UTF-8"));
 Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
 cipher.init(Cipher.DECRYPT_MODE, key, zeroIv);
 // 把加密数据的Base64串进行解码，转换为字节数组
 byte[] bytes = Base64Util.decodeToBytes(dest);
 // 明文的字节数组
 byte[] decryptBytes = cipher.doFinal(bytes);
 return new String(decryptBytes, "UTF-8");
 }

 /**
 * 通过密钥字符串生成 密钥Key
 */
 private static Key getKey(String keyString) {
 try {
// String key = Base64Util.decode(keyString);
 DESKeySpec keySpec = new DESKeySpec(keyString.getBytes("UTF-8"));
 SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
 Key secretKey = keyFactory.generateSecret(keySpec);
 return secretKey;
 } catch (NoSuchAlgorithmException e) {
 e.printStackTrace();
 } catch (InvalidKeyException e) {
 e.printStackTrace();
 } catch (UnsupportedEncodingException e) {
 e.printStackTrace();
 } catch (InvalidKeySpecException e) {
 e.printStackTrace();
 }
 return null;
 }
}