使用密钥加密、解密实例

package com.xiaohe.mianshi1;

import java.io.IOException;

import java.security.SecureRandom;

import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

import Decoder.BASE64Decoder;

import Decoder.BASE64Encoder;

public class DesUtil {

private final static String DES = “DES”;

public static void main(String[] args) {
String data = "我爱你！！";
String key = "123116爱11";
System.out.println(enctypt(data, key));

System.out.println(decrypt(enctypt(data, key), key));
}

public static String enctypt(String data, String key) {
byte[] bt = encrypt(data.getBytes(), key.getBytes());
String strs = new BASE64Encoder().encode(bt);
return strs;
}

public static String decrypt(String data, String key) {
System.out.println("data++++" + data);
if (data == null) {
return null;
}
BASE64Decoder decoder = new BASE64Decoder();
byte[] buf = null;
try {
buf = decoder.decodeBuffer(data);
} catch (IOException e) {
// TODO Auto-generated catch block
System.out.println(1);
e.printStackTrace();
}
byte[] bt = decrypt(buf, key.getBytes());
return new String(bt);
}

/*
* 加密
*/
private static byte[] encrypt(byte[] data, byte[] key) {
// 生成一个可信任随机的数源
try {
SecureRandom sr = new SecureRandom();

// 从原始密码数据创建DESkeySpec
DESKeySpec dks = new DESKeySpec(key);

// 创建一个密钥工厂，然后用它把DESKeySpec转换为SecrekKey对象
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
SecretKey secretKey = keyFactory.generateSecret(dks);

// Cipher对象实机完成加密操作
Cipher cipher = Cipher.getInstance(DES);

// 用密钥初始化Cipher对象
cipher.init(Cipher.ENCRYPT_MODE, secretKey, sr);

return cipher.doFinal(data);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
}

/*
* 解密
*/
private static byte[] decrypt(byte[] data, byte[] key) {
try {
// 生成一个可信任随机的数源
SecureRandom sr = new SecureRandom();

// 从原始密码数据创建DESkeySpec
DESKeySpec dks = new DESKeySpec(key);

// 创建一个密钥工厂，然后用它把DESKeySpec转换为SecrekKey对象
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
SecretKey secretKey = keyFactory.generateSecret(dks);

// Cipher对象实机完成加密操作
Cipher cipher = Cipher.getInstance(DES);

// 用密钥初始化Cipher对象
cipher.init(Cipher.DECRYPT_MODE, secretKey, sr);

return cipher.doFinal(data);
} catch (Exception e) {
// TODO Auto-generated catch block
System.out.println("大事不好，您的系统受到严重攻击！！！");
return null;
}
}

}