DES加密

package aisino.comm;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
/** 
 * 
 * DES加密工具类 
 */  
public class DESUtil {
    private static final String TAG = "TAG";  
      
    /** 
     * 生成密钥 
     */  
    public static byte[] initKey() {  
        try {  
            //KeyGenerator 密钥生成器  
            KeyGenerator keyGenerator = KeyGenerator.getInstance("DES");  
            //初始化密钥生成器  
            keyGenerator.init(56);  
            //生成密钥  
            SecretKey secretKey = keyGenerator.generateKey();  
            return secretKey.getEncoded();  
        } catch (Exception e) {  
            //Log.e(TAG, "initKey: " + e.getMessage());  
        }
        return null;  
       
    }  
  
    /** 
     * DES加密 
     * 
     * @param data 需要加密的数据 
     * @param key  加密使用的密钥 
     * @return 加密后获取的字节数组 
     */  
    public static byte[] encrypt(byte[] data, byte[] key) {  
        //恢复密钥  
        SecretKey secretKey = new SecretKeySpec(key, "DES");  
        try {  
            //Cipher完成加密或解密工作  
            Cipher cipher = Cipher.getInstance("DES");  
            //根据密钥对Cipher进行初始化 ENCRYPT_MODE, DECRYPT_MODE  
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);  
            //加密  
            return cipher.doFinal(data);  
        } catch (Exception e) {  
           // Log.e(TAG, "encrypt: " + e.getMessage());  
        }  
        return null;  
    }  
  
    /** 
     * DES解密 
     */  
    /** 
     * @param data 密文对应的字节数组 
     * @param key  算法名字 
     * @return 解密后的字节数组 
     */  
    public static byte[] decrypt(byte[] data, byte[] key) {  
        SecretKey secretKey = new SecretKeySpec(key, "DES");  
        try {  
            Cipher cipher = Cipher.getInstance("DES");  
            cipher.init(Cipher.DECRYPT_MODE, secretKey);  
            return cipher.doFinal(data);  
        } catch (Exception e) {  
            //Log.e(TAG, "decrypt: " + e.getMessage());  
        }  
        return null;  
    } 
    public static String byteArrayToHexStr(byte[] byteArray) {
        if (byteArray == null){
            return null;
        }
        char[] hexArray = "0123456789ABCDEF".toCharArray();
        char[] hexChars = new char[byteArray.length * 2];
        for (int j = 0; j < byteArray.length; j++) {
            int v = byteArray[j] & 0xFF;
            hexChars[j * 2] = hexArray[v >>> 4];
            hexChars[j * 2 + 1] = hexArray[v & 0x0F];
        }
        return new String(hexChars);
    }
    public static byte[] hexStrToByteArray(String str)
    {
        if (str == null) {
            return null;
        }
        if (str.length() == 0) {
            return new byte[0];
        }
        byte[] byteArray = new byte[str.length() / 2];
        for (int i = 0; i < byteArray.length; i++){
            String subStr = str.substring(2 * i, 2 * i + 2);
            byteArray[i] = ((byte)Integer.parseInt(subStr, 16));
        }
        return byteArray;
    }
}