package com.eabax.plugin.yundada.utils;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import org.apache.commons.codec.binary.Base64;
import sun.misc.BASE64Decoder;
public class DESEncryptHelper {
    private final static String DES = "DES";
    /**
     * 生成密钥
     * @param employeeCode
     */
    public static String getDESKey(String encryptStr){
        if (!CacheManager.getCache().containsKey("encryptKey_"+encryptStr)) {
            CacheManager.getCache().put("encryptKey_"+encryptStr, encryptStr+"tablemiyaokey");
        }
        String key = (String) CacheManager.getCache().get("encryptKey_"+encryptStr);
        return key;
    }
     /**
     * Description 根据键值进行解密
     * @param data
     * @param key  加密键byte数组
     * @return
     * @throws IOException
     * @throws Exception
     */
    public static String decrypt(String data, String key) throws IOException,
            Exception {
        if (data == null)
            return null;
        BASE64Decoder decoder = new BASE64Decoder();
        byte[] buf = decoder.decodeBuffer(data);
        byte[] bt = decrypt(buf,key.getBytes());
        return new String(bt);
    }
    /**
     * 对字符串加密
     * @param str
     * @return
     * @throws InvalidKeyException
     * @throws IllegalBlockSizeException
     * @throws BadPaddingException
     * @throws InvalidKeySpecException
     * @throws NoSuchAlgorithmException
     * @throws NoSuchPaddingException
     */
    public static String getEncryptStr(String str,String encryptStr) throws InvalidKeyException,
            IllegalBlockSizeException, BadPaddingException,
            InvalidKeySpecException, NoSuchAlgorithmException,
            NoSuchPaddingException {
        //获取key
        String key = getDESKey(encryptStr);
        //获取密钥
        SecretKeyFactory factory = SecretKeyFactory.getInstance("DES");
        DESKeySpec keyspec = new DESKeySpec(key.getBytes());
        SecretKey deskey = factory.generateSecret(keyspec);
        // Cipher负责完成加密或解密工作
        Cipher c = Cipher.getInstance("DES");
        // 根据密钥，对Cipher对象进行初始化，DECRYPT_MODE表示加密模式 
        c.init(Cipher.ENCRYPT_MODE, deskey);
        byte[] src = str.getBytes();
        // 该字节数组负责保存加密的结果
        byte[] cipherByte = c.doFinal(src);
        String enstr = new String(Base64.encodeBase64(cipherByte));
        return enstr;
    }
     /**
     * Description 根据键值进行解密
     * @param data
     * @param key  加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        // 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);
        return cipher.doFinal(data);
    }
}