[网络协议]Java DES 加密解密工具类实现

DES(Data Encryption Standard)是一种对称加密算法，所谓对称加密就是加密和解密都是使用同一个密钥

引用依赖

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import java.security.SecureRandom;

主要方法

 private static final String PASSWORD_CRYPT_KEY = "abcdef123456ABCDEFRLCF";
    private final static String ALGORITHM = "DES";

 
    /**
     * 对数据进行DES加密.
     * @param data 待进行DES加密的数据
     * @return 返回经过DES加密后的数据
     * @throws Exception
     */
    public final static String decrypt(String data) throws Exception {
        return new String(decrypt(hex2byte(data.getBytes()),
                PASSWORD_CRYPT_KEY.getBytes()));
    }
    /**
     * 对用DES加密过的数据进行解密.
     * @param data DES加密数据
     * @return 返回解密后的数据
     * @throws Exception
     */
    public final static String encrypt(String data) throws Exception  {
        return byte2hex(encrypt(data.getBytes(), PASSWORD_CRYPT_KEY
                .getBytes()));
    }

    /**
     * 用指定的key对数据进行DES加密.
     * @param data 待加密的数据
     * @param key DES加密的key
     * @return 返回DES加密后的数据
     * @throws Exception
     */
    private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        SecureRandom sr = new SecureRandom();
        DESKeySpec dks = new DESKeySpec(key);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
        SecretKey securekey = keyFactory.generateSecret(dks);
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);
        return cipher.doFinal(data);
    }
    /**
     * 用指定的key对数据进行DES解密.
     * @param data 待解密的数据
     * @param key DES解密的key
     * @return 返回DES解密后的数据
     * @throws Exception
     */
    private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        SecureRandom sr = new SecureRandom();
        DESKeySpec dks = new DESKeySpec(key);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
        SecretKey securekey = keyFactory.generateSecret(dks);
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);
        return cipher.doFinal(data);
    }
    public static byte[] hex2byte(byte[] b) {
        if ((b.length % 2) != 0)
            throw new IllegalArgumentException("长度不是偶数");
        byte[] b2 = new byte[b.length / 2];
        for (int n = 0; n < b.length; n += 2) {
            String item = new String(b, n, 2);
            b2[n / 2] = (byte) Integer.parseInt(item, 16);
        }
        return b2;
    }
    public static 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;
        }
        return hs.toUpperCase();
    }

测试演示

  public static void main(String[] args) throws Exception {
          String md5Password = "123423@_asdf";
          String str = DES.encrypt(md5Password);
          System.out.println("加密后结果str: " + str);
          str = DES.decrypt(str);
          System.out.println("解密后结果str: " + str);
      }