DES 加解密的封装和使用的例子

2008-02-23 09:54:53来源：互联网阅读 ()

原创：zhouxianli1978@msn.com ,欢迎喜欢Java的网友加我

DES加密封装

package org.jtool.desutils;
import java.security.SecureRandom;
import javax.crypto.*;
import javax.crypto.spec.DESKeySpec;
public class DESEncrypt {
private byte[] desKey;
public DESEncrypt(byte[] desKey) {
this.desKey = desKey;
}
public byte[] doEncrypt(byte[] plainText) throws Exception {
// DES算法要求有一个可信任的随机数源
SecureRandom sr = new SecureRandom();
byte rawKeyData[] = desKey;/* 用某种方法获得密匙数据 */
// 从原始密匙数据创建DESKeySpec对象
DESKeySpec dks = new DESKeySpec(rawKeyData);
// 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("DES");
SecretKey key = keyFactory.generateSecret(dks);
// Cipher对象实际完成加密操作
Cipher cipher = Cipher.getInstance("DES");
// 用密匙初始化Cipher对象
cipher.init(Cipher.ENCRYPT_MODE, key, sr);
// 现在，获取数据并加密
byte data[] = plainText;/* 用某种方法获取数据 */
// 正式执行加密操作
byte encryptedData[] = cipher.doFinal(data);
return encryptedData;
}
}

DES解密封装

package org.jtool.desutils;
import java.security.SecureRandom;
import javax.crypto.*;
import javax.crypto.spec.DESKeySpec;
public class DESDecrypt {
private byte[] desKey;
public DESDecrypt(byte[] desKey) {
this.desKey = desKey;
}
public byte[] doDecrypt(byte[] encryptText) throws Exception {
// DES算法要求有一个可信任的随机数源
SecureRandom sr = new SecureRandom();
byte rawKeyData[] = desKey; /* 用某种方法获取原始密匙数据 */
// 从原始密匙数据创建一个DESKeySpec对象
DESKeySpec dks = new DESKeySpec(rawKeyData);
// 创建一个密匙工厂，然后用它把DESKeySpec对象转换成
// 一个SecretKey对象
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey key = keyFactory.generateSecret(dks);
// Cipher对象实际完成解密操作
Cipher cipher = Cipher.getInstance("DES");
// 用密匙初始化Cipher对象
cipher.init(Cipher.DECRYPT_MODE, key, sr);
// 现在，获取数据并解密
byte encryptedData[] = encryptText;/* 获得经过加密的数据 */
// 正式执行解密操作
byte decryptedData[] = cipher.doFinal(encryptedData);
return decryptedData;
}
}

DES加解密使用样例

package org.jtool.desutils;
/**
*
*/
public class DESTest {
public static void main(String[] args) throws Exception {
String key = "ABCDEFGH";
String value = "AABBCCDDEE";
DESEncrypt desEncrypt = new DESEncrypt(key.getBytes());
byte[] encryptText = desEncrypt.doEncrypt(value.getBytes());
System.out.println("doEncrypt - " toHexString(encryptText));
System.out.println("doEncrypt - " new String(encryptText));
DESDecrypt desDecrypt = new DESDecrypt(key.getBytes());
byte[] decryptText = desDecrypt.doDecrypt(encryptText);
System.out.println("doDecrypt - " new String(decryptText));
System.out.println("doDecrypt - " toHexString(decryptText));
}
/**
* 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();
}
}