Imooc_JAVA實現對稱加密2-1 JAVA-對稱加密算法3DES

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Imooc_JAVA實現對稱加密2-1 JAVA-對稱加密算法3DES

package DES;

import java.security.SecureRandom;

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.DESedeKeySpec;

import org.apache.commons.codec.binary.Hex;

public class By3DES {


    private static String src = "imooc security 3des";


    public static void main(String[] args) {
        jdk3DES();
    }//main方法結束



    private static void jdk3DES(){
        try {
            //初始化KeyGenerator    Key生成器
            KeyGenerator keygenerator = KeyGenerator.getInstance("DESede");
//          keygenerator.init(168);
//          SecureRandom()生成默認長度的類
            keygenerator.init(new SecureRandom());
            //調用方法生成密匙secretKey   生成祕鑰
            SecretKey secretKey = keygenerator.generateKey();
            //密鑰進行getEncoded()獲取比特編碼byte[]
            byte[] byteskey = secretKey.getEncoded();


            //KEY的轉換

            //實例化DES的相關內容
            DESedeKeySpec desKeySpec = new DESedeKeySpec(byteskey);
            //通過祕鑰的工廠實例化一個自身的類  getInstance("")的參數爲指定的加密方式
            SecretKeyFactory factory = SecretKeyFactory.getInstance("DESede");
            //通過factory調用方法生成祕鑰     
//          generateSecret()參數爲祕鑰材料desKeySpec   該生成我們所需要的祕鑰
            SecretKey convertsecretKey =factory.generateSecret(desKeySpec);


            //KEY轉換完之後      Cipher類的實例來進行加密和解密操作
            //getInstance("加解密算法/工作方式/填充方式")
            Cipher cipher = Cipher.getInstance("DESede/ECB/PKCS5Padding");
            //cipher.init(opmode, certificate);  第一個參數爲模式  第二個參數爲轉換後的KEY
//          Cipher.ENCRYPT_MODE加密模式     轉換後的KEY:convertsecretKey
            cipher.init(Cipher.ENCRYPT_MODE, convertsecretKey);
            //doFinal(input);  input即使要被加密的內容
            byte[] result = cipher.doFinal(src.getBytes());

            System.out.println("jdk 3desede encrypt:"+Hex.encodeHexString(result));


            //解密
            //cipher.init(opmode, certificate);  第一個參數爲模式  第二個參數爲轉換後的KEY
//          Cipher.ENCRYPT_MODE解密模式     轉換後的KEY:convertsecretKey
            cipher.init(Cipher.DECRYPT_MODE, convertsecretKey);
            result = cipher.doFinal(result);
            System.out.println("jdk 3desede decrypt:"+new String(result));

        } catch (Exception e) {
            e.printStackTrace();
        }
    }//jdk3des()方法



    private static void bc3DES(){
        //作業
    }



}