Lock

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.IO;
using System.Text;


namespace Lock
{
	/// <summary>
	/// Summary description for Form1.
	/// </summary>
	
	public class Form1 : System.Windows.Forms.Form
	{
		/// <summary>
		/// own created field
		/// </summary>

        About abt;
		String file;
		String password ;
		/// <summary>
		/// system created
		/// </summary>
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.Button button1;
		private System.Windows.Forms.Label label2;
		private System.Windows.Forms.Label label3;
		private System.Windows.Forms.TextBox ffield;
		private System.Windows.Forms.TextBox pass;
		private System.Windows.Forms.TextBox c_pass;
		private System.Windows.Forms.Button button2;
		private System.Windows.Forms.Button button3;
		private System.Windows.Forms.OpenFileDialog ofd;
		private System.Windows.Forms.Button button4;
		private System.Windows.Forms.Button button5;
		/// <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
			//
            abt = new About(this);
		}

		/// <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.label1 = new System.Windows.Forms.Label();
            this.ffield = new System.Windows.Forms.TextBox();
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.label2 = new System.Windows.Forms.Label();
            this.pass = new System.Windows.Forms.TextBox();
            this.button3 = new System.Windows.Forms.Button();
            this.label3 = new System.Windows.Forms.Label();
            this.c_pass = new System.Windows.Forms.TextBox();
            this.ofd = new System.Windows.Forms.OpenFileDialog();
            this.button4 = new System.Windows.Forms.Button();
            this.button5 = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // label1
            // 
            this.label1.Location = new System.Drawing.Point(24, 24);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(112, 16);
            this.label1.TabIndex = 0;
            this.label1.Text = "Enter File Name";
            // 
            // ffield
            // 
            this.ffield.BackColor = System.Drawing.SystemColors.Info;
            this.ffield.Location = new System.Drawing.Point(152, 24);
            this.ffield.Name = "ffield";
            this.ffield.Size = new System.Drawing.Size(152, 20);
            this.ffield.TabIndex = 1;
            this.ffield.TextChanged += new System.EventHandler(this.ffield_TextChanged);
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(328, 16);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(112, 24);
            this.button1.TabIndex = 2;
            this.button1.Text = "Browse";
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // button2
            // 
            this.button2.Location = new System.Drawing.Point(24, 136);
            this.button2.Name = "button2";
            this.button2.Size = new System.Drawing.Size(120, 24);
            this.button2.TabIndex = 5;
            this.button2.Text = "Encrypt/Decrypt";
            this.button2.Click += new System.EventHandler(this.button2_Click);
            // 
            // label2
            // 
            this.label2.Location = new System.Drawing.Point(24, 64);
            this.label2.Name = "label2";
            this.label2.Size = new System.Drawing.Size(112, 24);
            this.label2.TabIndex = 4;
            this.label2.Text = "Enter Password";
            // 
            // pass
            // 
            this.pass.BackColor = System.Drawing.SystemColors.Info;
            this.pass.Location = new System.Drawing.Point(152, 56);
            this.pass.Name = "pass";
            this.pass.PasswordChar = '*';
            this.pass.Size = new System.Drawing.Size(152, 20);
            this.pass.TabIndex = 3;
            this.pass.TextChanged += new System.EventHandler(this.pass_TextChanged);
            // 
            // button3
            // 
            this.button3.DialogResult = System.Windows.Forms.DialogResult.Cancel;
            this.button3.Location = new System.Drawing.Point(304, 136);
            this.button3.Name = "button3";
            this.button3.Size = new System.Drawing.Size(104, 24);
            this.button3.TabIndex = 6;
            this.button3.Text = "Exit";
            this.button3.Click += new System.EventHandler(this.button3_Click);
            // 
            // label3
            // 
            this.label3.Location = new System.Drawing.Point(24, 96);
            this.label3.Name = "label3";
            this.label3.Size = new System.Drawing.Size(112, 24);
            this.label3.TabIndex = 7;
            this.label3.Text = "Confirm Password";
            // 
            // c_pass
            // 
            this.c_pass.BackColor = System.Drawing.SystemColors.Info;
            this.c_pass.Location = new System.Drawing.Point(152, 88);
            this.c_pass.Name = "c_pass";
            this.c_pass.PasswordChar = '+';
            this.c_pass.Size = new System.Drawing.Size(152, 20);
            this.c_pass.TabIndex = 4;
            // 
            // button4
            // 
            this.button4.Location = new System.Drawing.Point(328, 56);
            this.button4.Name = "button4";
            this.button4.Size = new System.Drawing.Size(112, 24);
            this.button4.TabIndex = 8;
            this.button4.Text = "Clear";
            this.button4.Click += new System.EventHandler(this.button4_Click);
            // 
            // button5
            // 
            this.button5.Location = new System.Drawing.Point(160, 136);
            this.button5.Name = "button5";
            this.button5.Size = new System.Drawing.Size(120, 24);
            this.button5.TabIndex = 9;
            this.button5.Text = "About";
            this.button5.Click += new System.EventHandler(this.button5_Click);
            // 
            // Form1
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(255)))), ((int)(((byte)(192)))), ((int)(((byte)(192)))));
            this.ClientSize = new System.Drawing.Size(456, 190);
            this.Controls.Add(this.button5);
            this.Controls.Add(this.button4);
            this.Controls.Add(this.c_pass);
            this.Controls.Add(this.label3);
            this.Controls.Add(this.button3);
            this.Controls.Add(this.pass);
            this.Controls.Add(this.label2);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.ffield);
            this.Controls.Add(this.label1);
            this.Name = "Form1";
            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
            this.Text = "Lock File";
            this.ResumeLayout(false);
            this.PerformLayout();

		}
		#endregion

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new Form1());
		}

		private void button2_Click(object sender, System.EventArgs e)
		{
			if(ffield.Text=="" )
			{
				MessageBox.Show("File Name is empty");
				return;
			}
			if(pass.Text=="" )
			{
				MessageBox.Show("Password Can't be Null");
				return;
			}

			if((pass.Text!=c_pass.Text)||pass.Text=="")
			{
				MessageBox.Show("password doesnot Match");
				return;
			}
				
			const int bufSize =1048576 ;
			String fileName = file;
			String key = password;
			FileStream stream = null;
			try
			{
				try
				{
					// open file for reading & writing
					stream = File.Open(fileName , FileMode.Open ,FileAccess.ReadWrite ) ;
				}
				catch(Exception ex)
				{
					MessageBox.Show(ex.Message);
					throw;
				}
				// wrap a reader & writer around the file
				BinaryReader reader = new BinaryReader(stream);
				BinaryWriter writer = new BinaryWriter(stream);
             
				// convert the key to byte array
				ASCIIEncoding enc = new ASCIIEncoding ();
				byte[] keyBytes = enc.GetBytes (key);

             
				// Allocate an I/O buffer & key buffer
				byte[] buffer = new byte[bufSize];
				byte[] keybuf = new byte[bufSize + keyBytes.Length - 1];
             
				// Replicate the byte array in the key buffer to create
				// an encryption key whose size equals or exceeds the
				// size of the I/O buffer
				int count = (1024 + keyBytes.Length-1)/keyBytes.Length;
				for( int i=0 ; i<count ; i++)
					Array.Copy( keyBytes , 0 , keybuf , i*keyBytes.Length , keyBytes.Length);
           
				// Read the file in bufsize blocks, XOR-encrypt each block,
				// and write the encrypted block back to the file
				long lBytesRemaining = stream.Length;
				while (lBytesRemaining>0)
				{
					long lPosition = stream.Position ;
					int nBytesRequested = (int)System.Math.Min(bufSize , lBytesRemaining) ; 
					int nBytesRead = reader.Read (buffer, 0, nBytesRequested);

					for (int i=0; i<nBytesRead; i++)
						buffer[i] ^= keybuf[i];									

					stream.Seek (lPosition, SeekOrigin.Begin);
					writer.Write (buffer, 0, nBytesRead);
					lBytesRemaining -= nBytesRead;
				}
				MessageBox.Show(fileName + " is crypted");
			}
			catch (Exception x)
			{
				Console.WriteLine(x.Message) ;
			}           
			finally
			{
				if (stream != null)
					stream.Close ();
			}			
		}

	
/// <summary>
/// 
/// </summary>
		int FilterIndex = -1;
		private void button1_Click(object sender, System.EventArgs e)
		{
			OpenFileDialog ofd = new OpenFileDialog();
		
			ofd.Filter=	"Image Files (JPG,JPEG, GIF, BMP,TIFF,PNG, etc.)|*.jpg;*.jpeg;*.gif;*.bmp;*.tif;*.tiff;*.png|" +
				"Executable Files ( *.bat, *.com, *.exe)|*.bat;*.com;*.exe|"+
				"All files (*.*)|*.*";
		
			if (FilterIndex != -1)
				ofd.FilterIndex = FilterIndex;
			if (ofd.ShowDialog() == DialogResult.OK)
			{
				string FileName = ofd.FileName ;
				if (FileName.Length !=0)
				{
					FilterIndex = ofd.FilterIndex ;
					try
					{
						ffield.Text = FileName ;
						file = FileName ;
						string [] parts = FileName.Split('\\');
						Text = " ImageViewer - " + parts[parts.Length-1];
						Invalidate();
					}
					catch(ArgumentException)
					{
						MessageBox.Show(String.Format 
							( "{0} is not a valid image file" , FileName) , "Error" ,
							MessageBoxButtons.OK , MessageBoxIcon.Error);
					}
				}
			}
			
		}

		private void ffield_TextChanged(object sender, System.EventArgs e)
		{
			file = ffield.Text ;
		}

		private void pass_TextChanged(object sender, System.EventArgs e)
		{
			password = pass.Text ;
		}

		private void button3_Click(object sender, System.EventArgs e)
		{
			Application.Exit();
		}

		private void button4_Click(object sender, System.EventArgs e)
		{
			ffield.Text = "";
			pass.Text = "";
			c_pass.Text="";
		}

        private void button5_Click(object sender, EventArgs e)
        {
            
            abt.Show();
        }
	}  
}