private void generateBtn_Click(object sender, EventArgs e)

        {

            string pwd = pwdtxt.Text;

            if(pwd==null ||pwd.Length==)

            {

                return;

            }

            string resultPwd = EncryptDES(pwd,"");

            resultPwdTxt.Text = resultPwd;

        }

/**/

        /// <summary>

        /// DES加密字符串

        /// </summary>

        /// <param name="encryptString">待加密的字符串</param>

        /// <param name="encryptKey">加密密钥</param>

        /// <returns>加密成功返回加密后的字符串，失败返回源串</returns>

        private string  EncryptDES(string encryptString, string encryptKey)

        {

            try

            {

                if (encryptKey.Length < )

                {

                    encryptKey += "@#$%^&*!";

                }

                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring (,));

                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);

                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();

                MemoryStream mStream = new MemoryStream();

                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbKey), CryptoStreamMode.Write);

                cStream.Write(inputByteArray, , inputByteArray.Length);

                cStream.FlushFinalBlock();

                return Convert.ToBase64String(mStream.ToArray());

            }

            catch

            {

                return encryptString;

            }

        }

        /**/

        /// <summary>

        /// DES解密字符串

        /// </summary>

        /// <param name="decryptString">待解密的字符串</param>

        /// <param name="decryptKey">解密密钥,和加密密钥相同</param>

        /// <returns>解密成功返回解密后的字符串，失败返源串</returns>

        private string  DecryptDES(string decryptString, string decryptKey)

        {

            try

            {

                if (decryptKey.Length < )

                {

                    decryptKey += "@#$%^&*!";

                }

                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey.Substring (,));

                byte[] inputByteArray = Convert.FromBase64String(decryptString);

                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();

                MemoryStream mStream = new MemoryStream();

                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbKey), CryptoStreamMode.Write);

                cStream.Write(inputByteArray, , inputByteArray.Length);

                cStream.FlushFinalBlock();

                return Encoding.UTF8.GetString(mStream.ToArray());

            }

            catch

            {

                return decryptString;

            }

        }

        private void button1_Click(object sender, EventArgs e)

        {

            string resultPwd = resultPwdTxt.Text;

            string pwd = DecryptDES(resultPwd, "");

            textBox1.Text = pwd;

        }

public static string getdecodePwd(string currentConnectionStr)

        {

            Regex regex = new Regex("(;Password=)(.*)(;)", RegexOptions.IgnoreCase);

            MatchCollection matcheCollection = regex.Matches(currentConnectionStr);

            foreach (Match match in matcheCollection)

            {

                GroupCollection groups = match.Groups;

                if (groups.Count == )

                {

                    string enpwd = groups[].Value;

                    string depwd = DecryptDES(enpwd, "");

                    currentConnectionStr = regex.Replace(currentConnectionStr, ";Password=" + depwd + ";");

                }

            }

            return currentConnectionStr;

        }

        private static string DecryptDES(string decryptString, string decryptKey)

        {

            try

            {

                if (decryptKey.Trim().Length < )

                {

                    decryptKey += "@#$%^&*!";

                }

                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey.Substring(, ));

                byte[] inputByteArray = Convert.FromBase64String(decryptString);

                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();

                MemoryStream mStream = new MemoryStream();

                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbKey), CryptoStreamMode.Write);

                cStream.Write(inputByteArray, , inputByteArray.Length);

                cStream.FlushFinalBlock();

                return Encoding.UTF8.GetString(mStream.ToArray());

            }

            catch

            {

                return decryptString;

            }

        }

public static String getdecodePwd(String currentConnectionStr){

        Pattern  regex = Pattern.compile("(;Password=)(.*)(;)",Pattern.CASE_INSENSITIVE);

        Matcher matcher=regex.matcher(currentConnectionStr);

        if(matcher.find()&&matcher.groupCount()==3){

            String enpwd = matcher.group(2);

            String depwd = DecryptDES(enpwd, "");

            currentConnectionStr =currentConnectionStr.replaceAll("(;Password=)(.*)(;)",";Password=" + depwd + ";");

        }

        return currentConnectionStr;

    }

    private static String DecryptDES(String decryptString,String decryptKey){

        try{

            if(decryptKey.trim().length()<8){

                decryptKey += "@#$%^&*!";

            }

            String key=decryptKey.substring(0, 8);

            BASE64Decoder decoder = new BASE64Decoder();

            byte[] bytesrc = decoder.decodeBuffer(decryptString);

            Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

            DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));

            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");

            SecretKey secretKey = keyFactory.generateSecret(desKeySpec);

            IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));

            cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);

            byte[] retByte = cipher.doFinal(bytesrc);

            String result= new String(retByte);

            return result;

        }catch(Exception e){

            e.printStackTrace();

            return "";

        }

    }