对称加密DES加密

Posted 2020-12-30 chengyangyang

 

 

DES加密: des是对称加密,加密和解密需要相同的秘钥,它的密码最长56位,必须是8的倍数,秘钥越长,越安全.

package com.trm.util.encrypt;

import java.security.SecureRandom;

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

/**
 * <p>加密/解密
 * <p>
 * @author
 *
 */
public class Encryption {
    
    /**
     * DES密钥
     * 注意：DES加密和解密过程中，密钥长度都必须是8的倍数,最长为56位
     */
    private static final String key = "12345678";
    
    /**
     * DES加密
     * @param str
     * @return
     */
    @SuppressWarnings("restriction")
    public static String encrypt(String str) {
        String encryptStr = "";
        try{
            SecureRandom random = new SecureRandom();
            DESKeySpec desKey = new DESKeySpec(key.getBytes());
            //创建一个密匙工厂，然后用它把DESKeySpec转换成
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            SecretKey securekey = keyFactory.generateSecret(desKey);
            //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, securekey, random);
            //现在，获取数据并加密
            //正式执行加密操作
            encryptStr = new sun.misc.BASE64Encoder().encode(cipher.doFinal(str.getBytes()));
        }catch(Throwable e){
                e.printStackTrace();
        }
        return encryptStr;
    }
    
    /**
     * DES解密
     * @param str
     * @return
     */
    @SuppressWarnings("restriction")
    public static String decrypt(String str) {
        String decryptStr = "";
        try {
            // DES算法要求有一个可信任的随机数源
            SecureRandom random = new SecureRandom();
            // 创建一个DESKeySpec对象
            DESKeySpec desKey = new DESKeySpec(key.getBytes());
            // 创建一个密匙工厂
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            // 将DESKeySpec对象转换成SecretKey对象
            SecretKey securekey = keyFactory.generateSecret(desKey);
            // 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, securekey, random);
            // 真正开始解密操作
            decryptStr = new String(cipher.doFinal(new sun.misc.BASE64Decoder().decodeBuffer(str)));
        } catch (Exception e) {
            throw new RuntimeException("解密错误，错误信息：", e); 
        }
        return decryptStr;
    }
    
    public static void main(String[] args) {
        String jdbcPassword = "123";

        //String password = decrypt(jdbcPassword);
        System.out.println(encrypt(jdbcPassword));
    }
    
}