RemoteDesktopConnection\src\LogInfo.cs

namespace RDP
{
    class LogInfo
    {
        public string Ipaddress { get; set; }
        public string Username { get; set; }
        public string Password { get; set; }
    }
}

RemoteDesktopConnection\src\Program.cs

#define debug
using System;
using System.Text.RegularExpressions;

namespace RDP
{
    class Program
    {
        static void Main(string[] args)
        {

            var info = new LogInfo();
        #if debug
            Console.WriteLine("please enter ipAddress");
            while (true)
            {
                info.Ipaddress = Console.ReadLine();
                if (new Regex(RdpConstant.IpaddressPatten).IsMatch(info.Ipaddress))
                {
                    break;
                }
            }
            Console.WriteLine("please enter username");
            info.Username = Console.ReadLine();
            Console.WriteLine(info.Username);
            Console.WriteLine("please enter password");
            info.Password = Console.ReadLine();
         #else
            info.Ipaddress = "120";
            info.Username = "Adm";
            info.Password = "wu";
        #endif
            RdpHandler.Rrocess(info);
        }
    }
}

RemoteDesktopConnection\src\RdpConstant.cs

namespace RDP
{
    class RdpConstant
    {
        public static readonly string IpaddressPatten= @"^([1-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3}$";
        public static readonly string FilePath = "rdp.rdp";
        public static readonly string templatePath="../../encryption/TemplateRDP.txt";
    }
}

RemoteDesktopConnection\src\encryption\DataProtection.cs

using System;
using System.Runtime.InteropServices;
using System.Text;
using System.Security;

namespace RDP
{
    [Serializable()]
    public sealed class DataProtection
    {
        [Flags()]
        public enum CryptProtectPromptFlags
        {
            CRYPTPROTECT_PROMPT_ON_UNPROTECT = 0x01,
            CRYPTPROTECT_PROMPT_ON_PROTECT = 0x02,
            CRYPTPROTECT_PROMPT_RESERVED = 0x04,
            CRYPTPROTECT_PROMPT_STRONG = 0x08,
            CRYPTPROTECT_PROMPT_REQUIRE_STRONG = 0x10
        }

        [Flags()]
        public enum CryptProtectDataFlags
        {
            CRYPTPROTECT_UI_FORBIDDEN = 0x01,
            CRYPTPROTECT_LOCAL_MACHINE = 0x04,
            CRYPTPROTECT_CRED_SYNC = 0x08,
            CRYPTPROTECT_AUDIT = 0x10,
            CRYPTPROTECT_NO_RECOVERY = 0x20,
            CRYPTPROTECT_VERIFY_PROTECTION = 0x40,
            CRYPTPROTECT_CRED_REGENERATE = 0x80
        }

        public static string ProtectData(string data, string name)
        {
            return ProtectData(data, name,
                CryptProtectDataFlags.CRYPTPROTECT_UI_FORBIDDEN | CryptProtectDataFlags.CRYPTPROTECT_LOCAL_MACHINE);
        }

        public static byte[] ProtectData(byte[] data, string name)
        {
            return ProtectData(data, name,
                CryptProtectDataFlags.CRYPTPROTECT_UI_FORBIDDEN | CryptProtectDataFlags.CRYPTPROTECT_LOCAL_MACHINE);
        }

        public static string ProtectData(string data, string name, CryptProtectDataFlags flags)
        {
            byte[] dataIn = Encoding.Unicode.GetBytes(data);
            byte[] dataOut = ProtectData(dataIn, name, flags);

            if (dataOut != null)
                return (Convert.ToBase64String(dataOut));
            else
                return null;
        }


        private static byte[] ProtectData(byte[] data, string name, CryptProtectDataFlags dwFlags)
        {
            byte[] cipherText = null;

            // copy data into unmanaged memory
            DPAPI.DATA_BLOB din = new DPAPI.DATA_BLOB();
            din.cbData = data.Length;

            din.pbData = Marshal.AllocHGlobal(din.cbData);

            if (din.pbData.Equals(IntPtr.Zero))
                throw new OutOfMemoryException("Unable to allocate memory for buffer.");

            Marshal.Copy(data, 0, din.pbData, din.cbData);

            DPAPI.DATA_BLOB dout = new DPAPI.DATA_BLOB();

            try
            {
                bool cryptoRetval = DPAPI.CryptProtectData(ref din, name, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, dwFlags, ref dout);

                if (cryptoRetval) 
                {
                    int startIndex = 0;
                    cipherText = new byte[dout.cbData];
                    Marshal.Copy(dout.pbData, cipherText, startIndex, dout.cbData);
                    DPAPI.LocalFree(dout.pbData);
                }
                else
                {
                    int errCode = Marshal.GetLastWin32Error();
                    StringBuilder buffer = new StringBuilder(256);
                    Win32Error.FormatMessage(Win32Error.FormatMessageFlags.FORMAT_MESSAGE_FROM_SYSTEM, IntPtr.Zero, errCode, 0, buffer, buffer.Capacity, IntPtr.Zero);
                }
            }
            finally
            {
                if (!din.pbData.Equals(IntPtr.Zero))
                    Marshal.FreeHGlobal(din.pbData);
            }

            return cipherText;
        }

        internal static void InitPromptstruct(ref DPAPI.CRYPTPROTECT_PROMPTSTRUCT ps)
        {
            ps.cbSize = Marshal.SizeOf(typeof(DPAPI.CRYPTPROTECT_PROMPTSTRUCT));
            ps.dwPromptFlags = 0;
            ps.hwndApp = IntPtr.Zero;
            ps.szPrompt = null;
        }
    }

    [SuppressUnmanagedCodeSecurityAttribute()]
    internal class DPAPI
    {
        [DllImport("crypt32")]
        public static extern bool CryptProtectData(ref DATA_BLOB dataIn, string szDataDescr, IntPtr optionalEntropy, IntPtr pvReserved,
            IntPtr pPromptStruct, DataProtection.CryptProtectDataFlags dwFlags, ref DATA_BLOB pDataOut);

        [DllImport("crypt32")]
        public static extern bool CryptUnprotectData(ref DATA_BLOB dataIn, StringBuilder ppszDataDescr, IntPtr optionalEntropy,
            IntPtr pvReserved, IntPtr pPromptStruct, DataProtection.CryptProtectDataFlags dwFlags, ref DATA_BLOB pDataOut);

        [DllImport("Kernel32.dll")]
        public static extern IntPtr LocalFree(IntPtr hMem);

        [StructLayout(LayoutKind.Sequential)]
        public struct DATA_BLOB
        {
            public int cbData;
            public IntPtr pbData;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct CRYPTPROTECT_PROMPTSTRUCT
        {
            public int cbSize; // = Marshal.SizeOf(typeof(CRYPTPROTECT_PROMPTSTRUCT))
            public int dwPromptFlags; // = 0
            public IntPtr hwndApp; // = IntPtr.Zero
            public string szPrompt; // = null
        }
    }

    internal class Win32Error
    {
        [Flags()]
        public enum FormatMessageFlags : int
        {
            FORMAT_MESSAGE_ALLOCATE_BUFFER = 0x0100,
            FORMAT_MESSAGE_IGNORE_INSERTS = 0x0200,
            FORMAT_MESSAGE_FROM_STRING = 0x0400,
            FORMAT_MESSAGE_FROM_HMODULE = 0x0800,
            FORMAT_MESSAGE_FROM_SYSTEM = 0x1000,
            FORMAT_MESSAGE_ARGUMENT_ARRAY = 0x2000,
            FORMAT_MESSAGE_MAX_WIDTH_MASK = 0xFF,
        }

        [DllImport("Kernel32.dll")]
        public static extern int FormatMessage(FormatMessageFlags flags, IntPtr source, int messageId, int languageId,
            StringBuilder buffer, int size, IntPtr arguments);
    }
}

RemoteDesktopConnection\src\encryption\Rdp.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Text;

namespace RDP
{
    class RdpHandler
    {
        public static void Rrocess(LogInfo info) {
            if (string.IsNullOrEmpty(info.Username) || string.IsNullOrEmpty(info.Password)) {
                throw new ArgumentNullException("username and password can't be empty");
            }
            var pwstr = BitConverter.ToString(DataProtection.ProtectData(Encoding.Unicode.GetBytes(info.Password), "")).Replace("-", "");
            var rdpInfo = String.Format(File.ReadAllText(RdpConstant.templatePath), info.Ipaddress, info.Username, pwstr);
            File.WriteAllText(RdpConstant.FilePath,rdpInfo);
            _mstsc("mstsc " + RdpConstant.FilePath);
        }

        private static void _mstsc(String cmd)
        {
            Process p = new Process();
            p.StartInfo.FileName = "cmd.exe";
            p.StartInfo.UseShellExecute = false;
            p.StartInfo.RedirectStandardInput = true;
            p.StartInfo.CreateNoWindow = true;
            p.Start();
            p.StandardInput.WriteLine(cmd);
        }
    }
}

RemoteDesktopConnection\src\encryption\TemplateRDP.txt

screen mode id:i:2
use multimon:i:0
desktopwidth:i:1600
desktopheight:i:900
session bpp:i:32
winposstr:s:0,3,0,0,800,600
compression:i:1
keyboardhook:i:2
audiocapturemode:i:0
videoplaybackmode:i:1
connection type:i:2
networkautodetect:i:1
bandwidthautodetect:i:1
displayconnectionbar:i:1
enableworkspacereconnect:i:0
disable wallpaper:i:1
allow font smoothing:i:0
allow desktop composition:i:0
disable full window drag:i:1
disable menu anims:i:1
disable themes:i:0
disable cursor setting:i:0
bitmapcachepersistenable:i:1
audiomode:i:1
redirectprinters:i:1
redirectcomports:i:0
redirectsmartcards:i:1
redirectclipboard:i:1
redirectposdevices:i:0
autoreconnection enabled:i:1
authentication level:i:2
prompt for credentials:i:0
negotiate security layer:i:1
remoteapplicationmode:i:0
alternate shell:s:
shell working directory:s:
gatewayhostname:s:
gatewayusagemethod:i:4
gatewaycredentialssource:i:4
gatewayprofileusagemethod:i:0
promptcredentialonce:i:0
use redirection server name:i:0
rdgiskdcproxy:i:0
kdcproxyname:s:
drivestoredirect:s:
redirectdirectx:i:1
full address:s:{0}
username:s:{1}
password 51:b:{2}