备忘DES带向量的加密和解密与DES简单加密与解密

package com.ego.util;

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

public class DESCryption {
private static AlgorithmParameterSpec iv = null;// 加密算法的参数接口，IvParameterSpec是它的一个实现
private static Key key = null;

// 带向量的DES加密方法
/**
 * 
 * @param data 原文
 * @param DESkey key
 * @param DESIV 向量
 * @return 加密后转换成hex形式的密文字符串
 * @throws Exception
 */
public static String encode(String data, byte[] DESkey, byte[] DESIV)
		throws Exception {
	DESKeySpec keySpec = new DESKeySpec(DESkey);// 设置密钥参数
	iv = new IvParameterSpec(DESIV);// 设置向量
	SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");// 获得密钥工厂
	key = keyFactory.generateSecret(keySpec);// 得到密钥对象
	Cipher enCipher = Cipher.getInstance("DES/CBC/PKCS5Padding");// 得到加密对象Cipher
	enCipher.init(Cipher.ENCRYPT_MODE, key, iv);// 设置工作模式为加密模式，给出密钥和向量
	byte[] pasByte = enCipher.doFinal(data.getBytes("utf-8"));
	return byte2hex(pasByte);
}

// 带向量的DES解密方法
/**
 * 
 * @param data 加密后转换成hex形式的密文字符串
 * @param DESkey key
 * @param DESIV 向量
 * @return 原文
 * @throws Exception
 */
public static String decode(String data, byte[] DESkey, byte[] DESIV)
		throws Exception {
	DESKeySpec keySpec = new DESKeySpec(DESkey);// 设置密钥参数
	iv = new IvParameterSpec(DESIV);// 设置向量
	SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");// 获得密钥工厂
	key = keyFactory.generateSecret(keySpec);// 得到密钥对象
	Cipher deCipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
	deCipher.init(Cipher.DECRYPT_MODE, key, iv);
	byte[] buf = hex2byte(data.getBytes());
	byte[] pasByte = deCipher.doFinal(buf);
	return new String(pasByte);
}

//不带向量的DES加密方法
/**
 * 
 * @param dataString 原文
 * @param keyString key
 * @return 加密后转换成hex形式的密文字符串
 * @throws Exception
 */
public static String encrypt(String dataString, String keyString) throws Exception {
	byte[] data = dataString.getBytes();
	byte[] key =keyString.getBytes();
	// 生成一个可信任的随机数源
    SecureRandom sr = new SecureRandom();
    // 从原始密钥数据创建DESKeySpec对象
    DESKeySpec dks = new DESKeySpec(key);
    // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
    SecretKey securekey = keyFactory.generateSecret(dks);
    // Cipher对象实际完成加密操作
    Cipher cipher = Cipher.getInstance("DES");
    // 用密钥初始化Cipher对象
    cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);
    byte[] bt=cipher.doFinal(data);
    String strs=byte2hex(bt);
    return strs;
}
//不带向量的DES解密方法
/**
 * 
 * @param dataString 加密后转换成hex形式的密文字符串
 * @param keyString key
 * @return 原文
 * @throws Exception
 */
 public static String decrypt(String dataString, String keyString)throws Exception{
        if (dataString == null)
            return null;
        byte[] dataHex = dataString.getBytes();
		byte[] key =keyString.getBytes();
        byte[] data = hex2byte(dataHex);
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();
        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);
        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey securekey = keyFactory.generateSecret(dks);
        // Cipher对象实际完成解密操作
        Cipher cipher = Cipher.getInstance("DES");
        // 用密钥初始化Cipher对象
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);
		byte[] bt = cipher.doFinal(data);
		return new String(bt);
    }
 /**
     * 十六进制字符转换成byte数组
     * @param string.getByte
     * @return
     */
    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;
    }
    /**
     * byte数组转换成16进制字符串
     * @param b
     * @return
     */
    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
public static void main(String[] args) throws Exception {

// String result=DESCryption.decode("59782316F0DA48F6C2CD6F4E0BE6580A37A98DF27B3E623B2D07D651FA9ED1204AA6ECC637A45725126D6F177F3ACA1EF0FB5AE27B230664","20161108".getBytes(),"20161108".getBytes());
// String result=DESCryption.decode("5C77BDA7EE8096AF5E8DE236DAD59038DB7B8C7A856B09E5703191843F1A4AA0AC36BB835057C661F61F40E945DBE786513ACA1BFDC7AB876FC49E0879C6D07B","20161108".getBytes(),"20161108".getBytes());
String result=DESCryption.encode("{'uid':'admin','pwd':'21232f297a57a5a743894a0e4a801fc3'}","20161108".getBytes(),"20161108".getBytes());
System.out.println(result);
}
}