字符串加密DES

提前关于加密的方式，我目前知道的有MD5，DES等等。今天写一下使用DES的代码，方便下次使用。

package mocha.framework.hrbase.rest.utils;

import java.security.Key;

import javax.crypto.Cipher;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

/**
 * 
 * 使用DES加密与解密,可对byte[],String类型进行加密与解密 密文可使用String,byte[]存储.
 * 
 * String getEncString(String strMing)对strMing进行加密,返回String密文 String
 * getDesString(String strMi)对strMin进行解密,返回String明文
 * 
 * byte[] getEncCode(byte[] byteS)byte[]型的加密 byte[] getDesCode(byte[]
 * byteD)byte[]型的解密
 */

public final class DES {

	//自定义密钥
	private static final String DES_KEY_STRING = "jingfen_SFTP";
	private static Key KEY;

	/**
	 * 初始化密钥
	 */
	static {
		initKey(DES_KEY_STRING);
	}

	private DES() {
	}

	private static DES des = new DES();

	public static DES getInstance() {
		return des;
	}

	/**
	 * 从指定字符串生成密钥，密钥所需的字节数组长度为8位 不足8位时后面补0，超出8位只取前8位
	 * 
	 * @param arrBTmp
	 *            构成该字符串的字节数组
	 * 
	 * @return 生成的密钥
	 * @throws Exception
	 */
	private static Key getKey(byte[] arrBTmp) throws Exception {
		// 创建一个空的8位字节数组（默认值为0）
		byte[] arrB = new byte[8];
		// 将原始字节数组转换为8位
		for (int i = 0; i < arrBTmp.length && i < arrB.length; i++) {
			arrB[i] = arrBTmp[i];
		}
		// 生成密钥
		Key key = new javax.crypto.spec.SecretKeySpec(arrB, "DES");
		return key;
	}

	/**
	 * 根据参数生成KEY
	 * 
	 * @param strKey
	 */
	private static void initKey(String strKey) {
		try {
			// KeyGenerator _generator = KeyGenerator.getInstance("DES");
			// _generator.init(new SecureRandom(strKey.getBytes()));
			KEY = getKey(strKey.getBytes());
			// _generator.generateKey();
			// _generator = null;
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * 加密String明文输入,String密文输出
	 * 
	 * @param strMing
	 * @returno
	 */
	public static String getEncString(String strMing) {
		byte[] byteMi = null;
		byte[] byteMing = null;
		String strMi = "";
		BASE64Encoder base64en = new BASE64Encoder();
		try {
			byteMing = strMing.getBytes("UTF8");
			byteMi = getEncCode(byteMing);
			strMi = base64en.encode(byteMi);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			base64en = null;
			byteMing = null;
			byteMi = null;
		}
		return strMi;
	}

	/**
	 * 解密 以String密文输入,String明文输出
	 * 
	 * @param strMi
	 * @return
	 */
	public static String getDesString(String strMi) {
		BASE64Decoder base64De = new BASE64Decoder();
		byte[] byteMing = null;
		byte[] byteMi = null;
		String strMing = "";
		try {
			byteMi = base64De.decodeBuffer(strMi);
			byteMing =getDesCode(byteMi);
			strMing = new String(byteMing, "UTF8");
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			base64De = null;
			byteMing = null;
			byteMi = null;
		}
		return strMing;
	}

	/**
	 * 加密以byte[]明文输入,byte[]密文输出
	 * 
	 * @param byteS
	 * @return
	 */
	private static byte[] getEncCode(byte[] byteS) {
		byte[] byteFina = null;
		Cipher cipher;
		try {
			cipher = Cipher.getInstance("DES");
			cipher.init(Cipher.ENCRYPT_MODE, KEY);
			byteFina = cipher.doFinal(byteS);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			cipher = null;
		}
		return byteFina;
	}

	/**
	 * 解密以byte[]密文输入,以byte[]明文输出
	 * 
	 * @param byteD
	 * @return
	 */
	private static byte[] getDesCode(byte[] byteD) {
		Cipher cipher;
		byte[] byteFina = null;
		try {
			cipher = Cipher.getInstance("DES");
			cipher.init(Cipher.DECRYPT_MODE, KEY);
			byteFina = cipher.doFinal(byteD);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			cipher = null;
		}
		return byteFina;

	}

	public static void main(String[] args) {
		//加密字符串
		System.out.println(getEncString("22"));
		//解密密文
		System.out.println(getDesString("oEwwje/uXXo="));
	}

}