asp.net DES加密解密怎么弄

public string DecrytFun(string custData)
{
byte[] key = Encoding.ASCII.GetBytes("201206==");
DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
MemoryStream memoryStream = new MemoryStream(Convert.FromBase64String(custData));
CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateDecryptor(key, key), CryptoStreamMode.Read);
StreamReader reader = new StreamReader(cryptoStream);
return reader.ReadToEnd();
}

怎么把他写成exe的，并且在本程序目录执行的时候，1.txt是密文，每行一个，解密后输出到2.txt里面，最好能私信发个QQ或者联系方式，方便发代码。在线等。。。

xxx.aspx

<%@ Page Language="C#" EnableSessionState="True" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Web.Security" %>
<%@ Import Namespace="System.Security.Cryptography" %>
<script runat="server">
    public string DecrytFun(string custData)
    {
        byte[] key = Encoding.ASCII.GetBytes("201206==");
        DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
        MemoryStream memoryStream = new MemoryStream(Convert.FromBase64String(custData));
        CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateDecryptor(key, key), CryptoStreamMode.Read);
        StreamReader reader = new StreamReader(cryptoStream);
        return reader.ReadToEnd();
    }
    /// <summary>
    /// 
    /// </summary>
    /// <param name="source">要解密的文件路径</param>
    /// <param name="target">解密后保存的文件路径</param>
    public void DecryFile(string source, string target)
    {
        string s = File.ReadAllText(source);
        string[] arr = s.Replace("\r", "").Split('\n');
        System.Text.StringBuilder sb = new System.Text.StringBuilder();
        foreach (string _s in arr) if (_s.Trim() != "") sb.Append(DecrytFun(_s) + "\r\n");
        File.WriteAllText(target, sb.ToString().TrimEnd());
    }
    protected void Page_Load(Object sender, EventArgs args)
    {
        string source = Server.MapPath("1.txt"), target = Server.MapPath("2.txt");
        DecryFile(source, target);
        Response.Redirect("2.txt");
    }
</script>