C# des 加密 解密

    public class EncryptDecrypt
    {
        public static string EncryptString(string mes, string key)
        {
            byte[] inputBytes = ASCIIEncoding.UTF8.GetBytes(mes);

            MemoryStream outputStream = new MemoryStream();
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            des.Key = ASCIIEncoding.ASCII.GetBytes(key);
            des.IV = ASCIIEncoding.ASCII.GetBytes(key);
            ICryptoTransform desencrypt = des.CreateEncryptor();
            CryptoStream cryptostream = new CryptoStream(outputStream, desencrypt, CryptoStreamMode.Write);
            cryptostream.Write(inputBytes, 0, inputBytes.Length);
            cryptostream.FlushFinalBlock();
            cryptostream.Close();

            string outputString = Convert.ToBase64String(outputStream.ToArray());
            return outputString;
        }

        public static string DecryptString(string mes, string key)
        {
            byte[] inputBytes = Convert.FromBase64String(mes);

            MemoryStream outputStream = new MemoryStream();
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            des.Key = ASCIIEncoding.ASCII.GetBytes(key);
            des.IV = ASCIIEncoding.ASCII.GetBytes(key);
            ICryptoTransform desencrypt = des.CreateDecryptor();
            CryptoStream cryptostream = new CryptoStream(outputStream, desencrypt, CryptoStreamMode.Write);
            cryptostream.Write(inputBytes, 0, inputBytes.Length);
            cryptostream.FlushFinalBlock();
            cryptostream.Close();

            string outputString = ASCIIEncoding.UTF8.GetString(outputStream.ToArray());
            return outputString;
        }
    }