问题描述

关于java解密的问题，C#DES加密过的数据，用java解密

C#加密解密代码如下

 public static String sKey = "xxxxxx";
    /// <summary>
    /// 加密
    /// </summary>
    /// <param name="Text"></param>
    /// <returns></returns>
    public static String Encrypt(String EncryptText)
    {
        return Encrypt(EncryptText, sKey);
    }
    /// <summary>
    /// 加密数据
    /// </summary>
    /// <param name="Text"></param>
    /// <param name="sKey"></param>
    /// <returns></returns>
    public static String Encrypt(String Text, String sKey)
    {
        DESCryptoServiceProvider des = new DESCryptoServiceProvider();
//        DESKeySpec k = new DESKeySpec(sKey.getBytes("UTF-8"));
        byte[] inputByteArray;
        inputByteArray = Encoding.Default.GetBytes(Text);
        des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
        des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
        System.IO.MemoryStream ms = new System.IO.MemoryStream();
        CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
        cs.Write(inputByteArray, 0, inputByteArray.Length);
        cs.FlushFinalBlock();
        StringBuilder ret = new StringBuilder();
        foreach (byte b in ms.ToArray())
        {
            ret.AppendFormat("{0:X2}", b);
        }
        return ret.ToString();
    }

    /// <summary>
    /// 解密
    /// </summary>
    /// <param name="Text"></param>
    /// <returns></returns>
    public static String Decrypt(String MD5Text)
    {
        return Decrypt(MD5Text, sKey);
    }
    /// <summary>
    /// 解密数据
    /// </summary>
    /// <param name="Text"></param>
    /// <param name="sKey"></param>
    /// <returns></returns>
    public static String Decrypt(String Text, String sKey)
    {

        DESCryptoServiceProvider des = new DESCryptoServiceProvider();
        int len;
        len = Text.Length / 2;
        byte[] inputByteArray = new byte[len];
        int x, i;
        for (x = 0; x < len; x++)
        {
            i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
            inputByteArray[x] = (byte)i;
        }
        des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
        des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
        System.IO.MemoryStream ms = new System.IO.MemoryStream();
        CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
        cs.Write(inputByteArray, 0, inputByteArray.Length);
        cs.FlushFinalBlock();
        return Encoding.Default.GetString(ms.ToArray());
    }

我写的解密java代码如下

 private final byte[] DESkey = DigestUtils.md5Hex("xxxxxx").substring(0, 8).getBytes("UTF-8");// 设置密钥
       private final byte[] DESIV = DigestUtils.md5Hex("xxxxxx").substring(0, 8).getBytes("UTF-8");// 设置向量

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

       public CryptoTools() 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

       }

       public String decode(String data) throws Exception {
           Cipher deCipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
           deCipher.init(Cipher.DECRYPT_MODE, key, iv);
           BASE64Decoder base64Decoder = new BASE64Decoder();
           byte[] inputByteArray = base64Decoder.decodeBuffer(data);

           byte[] pasByte = deCipher.doFinal(inputByteArray);

           return new String(pasByte, "UTF-8");
       }
       public static void main(String[] args) {
           try {
               String test = "0608E27EC1E8A308A84E87D1A6FBC3B0";
               CryptoTools des = new CryptoTools();//自定义密钥
               System.out.println("加密前的字符："+test);
               System.out.println("解密后的字符："+des.decode(test));
           } catch (Exception e) {
               e.printStackTrace();
           }
       }

测试运行一直报错，求大神解答

javax.crypto.BadPaddingException: Given final block not properly padded
    at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:966)
    at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:824)
    at com.sun.crypto.provider.DESCipher.engineDoFinal(DESCipher.java:314)
    at javax.crypto.Cipher.doFinal(Cipher.java:2165)
    at com.walch.wx.util.md5.util.CryptoTools.decode(CryptoTools.java:59)
    at com.walch.wx.util.md5.util.CryptoTools.main(CryptoTools.java:69)
ERROR: JDWP Unable to get JNI 1.2 environment, jvm->GetEnv() return code = -2
JDWP exit error AGENT_ERROR_NO_JNI_ENV(183):  [util.c:840]

解决方案

java-MD5解密算法

解决方案二：

加解密的编码是否相同，是否都是字节或者字符串

解决方案三：

MD5 是不可逆算法。不能通过密钥来对密文进行解密，解密只能靠暴力破解。
如果需要可逆的加密方法，请考虑使用 DES,3DES,AES,RSA 等。