this is a windows application with 2 text boxes and one button:
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Text;
using System.Security;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Security.Permissions;
namespace WindowsApplication1
{
/// <summary>
/// Summary description for Form1.
/// </summary>
///
//[StrongNameIdentityPermission(SecurityAction.LinkDemand,
PublicKey="00240000048000009400000006020000002400005253413100040000010001002
72736AD6E5F9586BAC2D531EABC3ACC666C2F8EC879FA94F8F7B0327D2FF2ED523448F83C3D5
C5DD2DFC7BC99C5286B2C125117BF5CBE242B9D41750732B2BDFFE649C6EFB8E5526D526FDD1
30095ECDB7BF210809C6CDAD8824FAA9AC0310AC3CBA2AA0523567B2DFA7FE250B30FACBD62D
4EC99B94AC47C7D3B28F1F6E4C8")]
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.TextBox txtIn;
private System.Windows.Forms.TextBox txtOut;
private System.Windows.Forms.Button btnDec;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;
public Form1()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.txtIn = new System.Windows.Forms.TextBox();
this.txtOut = new System.Windows.Forms.TextBox();
this.btnDec = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// txtIn
//
this.txtIn.Location = new System.Drawing.Point(8, 8);
this.txtIn.Multiline = true;
this.txtIn.Name = "txtIn";
this.txtIn.Size = new System.Drawing.Size(328, 104);
this.txtIn.TabIndex = 0;
this.txtIn.Text = "";
//
// txtOut
//
this.txtOut.Location = new System.Drawing.Point(8, 200);
this.txtOut.Multiline = true;
this.txtOut.Name = "txtOut";
this.txtOut.Size = new System.Drawing.Size(328, 104);
this.txtOut.TabIndex = 0;
this.txtOut.Text = "textBox1";
//
// btnDec
//
this.btnDec.Location = new System.Drawing.Point(128, 144);
this.btnDec.Name = "btnDec";
this.btnDec.TabIndex = 1;
this.btnDec.Text = "try";
this.btnDec.Click += new System.EventHandler(this.btnDec_Click);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(528, 453);
this.Controls.Add(this.btnDec);
this.Controls.Add(this.txtIn);
this.Controls.Add(this.txtOut);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
private void btnDec_Click(object sender, System.EventArgs e)
{
//MessageBox.Show ("test");
txtOut.Text = LocalUnprotectData ( txtIn.Text);
}
public static string LocalUnprotectData(string data)
{
byte[] buffer1 = Convert.FromBase64String(data);
byte[] buffer2 = LocalUnprotectData(buffer1);
string text1 = null;
if (buffer2 == null)
{
return text1;
}
while (buffer2.Length != 0)
{
return Encoding.Unicode.GetString(buffer2);
}
return string.Empty;
}
public static byte[] LocalUnprotectData(byte[] data)
{
return UnprotectData(data, 1);
}
private static byte[] UnprotectData(byte[] data, int dwFlags)
{
NativeMethods.DATA_BLOB data_blob1;
NativeMethods.DATA_BLOB data_blob2;
byte[] buffer1 = null;
data_blob1 = new NativeMethods.DATA_BLOB();
data_blob1.cbData = data.Length;
data_blob1.pbData = Marshal.AllocHGlobal(data_blob1.cbData);
Marshal.Copy(data, 0, data_blob1.pbData, data_blob1.cbData);
data_blob2 = new NativeMethods.DATA_BLOB();
try
{
if (NativeMethods.CryptUnprotectData(ref data_blob1, null, IntPtr.Zero,
IntPtr.Zero, IntPtr.Zero, dwFlags, ref data_blob2))
{
buffer1 = new byte[data_blob2.cbData];
Marshal.Copy(data_blob2.pbData, buffer1, 0, data_blob2.cbData);
byte[] buffer2 = new byte[data_blob2.cbData];
Marshal.Copy(data_blob2.pbData, buffer2, 0, data_blob2.cbData);
NativeMethods.LocalFree(data_blob2.pbData);
data_blob2.pbData = IntPtr.Zero;
return buffer1;
}
int num1 = Marshal.GetLastWin32Error();
string text1 = string.Format("CryptUnprotectData: Win32 error:{0}", num1);
throw new Exception(text1);
}
finally
{
if (data_blob1.pbData != IntPtr.Zero)
{
Marshal.FreeHGlobal(data_blob1.pbData);
}
while (data_blob2.pbData != IntPtr.Zero)
{
NativeMethods.LocalFree(data_blob2.pbData);
data_blob2.pbData = IntPtr.Zero;
break;
}
}
return buffer1;
}
}
}
internal sealed class NativeMethods
{
// Methods
public NativeMethods()
{
}
// [DllImport("crypt32", CharSet=CharSet.Auto, SetLastError=true)]
// internal static extern bool CryptProtectData(ref DATA_BLOB dataIn, string
szDataDescr, IntPtr optionalEntropy, IntPtr pvReserved, IntPtr
pPromptStruct, int dwFlags, ref DATA_BLOB pDataOut);
[DllImport("crypt32", CharSet=CharSet.Auto, SetLastError=true)]
internal static extern bool CryptUnprotectData(ref DATA_BLOB dataIn,
StringBuilder ppszDataDescr, IntPtr optionalEntropy, IntPtr pvReserved,
IntPtr pPromptStruct, int dwFlags, ref DATA_BLOB pDataOut);
[DllImport("kernel32.dll")]
internal static extern IntPtr LocalFree(IntPtr hMem);
// Nested Types
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Unicode)]
public struct DATA_BLOB
{
public int cbData;
public IntPtr pbData;
}
}
