package security;

/**
*安全程序 DESede/DES测试
*/
import java.security.*;
import javax.crypto.*;

public class Testdes {

  public static void main(String[] args){

    Testdes my=new Testdes();
    my.run();
  }

  public void run() {

    //添加新安全算法,如果用JCE就要把它添加进去
    Security.addProvider(new com.sun.crypto.provider.SunJCE());
    String Algorithm="DES"; //定义 加密算法,可用 DES,DESede,Blowfish
    String myinfo="要加密的信息";

    try {

      //生成密钥
      KeyGenerator keygen = KeyGenerator.getInstance(Algorithm);
      SecretKey deskey = keygen.generateKey();

      //加密
      System.out.println("加密前的二进串:"+byte2hex(myinfo.getBytes()));
      System.out.println("加密前的信息:"+myinfo);

      Cipher c1 = Cipher.getInstance(Algorithm);

      //用密钥来加密，方式：加密模式
      c1.init(Cipher.ENCRYPT_MODE,deskey);

      byte[] cipherByte=c1.doFinal(myinfo.getBytes());

      System.out.println("加密后的二进串:"+byte2hex(cipherByte));

      //解密
      c1 = Cipher.getInstance(Algorithm);

      //用密钥来解密，方式：解密模式
      c1.init(Cipher.DECRYPT_MODE,deskey);

      byte[] clearByte=c1.doFinal(cipherByte);

      System.out.println("解密后的二进串:"+byte2hex(clearByte));
      System.out.println("解密后的信息:"+(new String(clearByte)));

    } catch (java.security.NoSuchAlgorithmException e1) {
      e1.printStackTrace();
    } catch (javax.crypto.NoSuchPaddingException e2) {
      e2.printStackTrace();
    } catch (java.lang.Exception e3) {
      e3.printStackTrace();
    }

  }

  //二进制转字符串
  //把二进制数组转换成十六进制串，用：号隔开
  //一个字节（8位）对应于一个两位的十六进制数
  public String byte2hex(byte[] b) {

    String hs="";
    String stmp="";

    for (int n=0;n<b.length;n++) {

      stmp=(java.lang.Integer.toHexString(b[n] & 0XFF));

      if (stmp.length()==1) hs=hs+"0"+stmp;
      else hs=hs+stmp;

      if (n<b.length-1) hs=hs+":";

    }

    return hs.toUpperCase();

  }

}