using System;
using System.Windows.Forms;
using System.IO;
using System.Text;
using System.Security.Cryptography;
namespace des
{
	/// <summary>
	/// des_ed 的摘要說明。
	/// </summary>
	public class des_ed
	{
		private byte[] TheKey= new byte[8]; 
		// 在向量中放入一些隨機數據
		private  byte[] Vector ={0x82, 0x84, 0x16, 0xE6, 0x58, 0x15, 0xED, 0x4E};
		public des_ed()
		{
			//
			// TODO: 在此處添加構造函數邏輯
			//
		}
		public string sha1ec(string strKey)
		{
			byte[] arrByte=new byte[strKey.Length];
			ASCIIEncoding  AscEncod=new ASCIIEncoding();
            int i = 0;
			AscEncod.GetBytes(strKey, i, strKey.Length, arrByte, i);
			// 獲得密碼的Hash值
			SHA1CryptoServiceProvider hashSha=new SHA1CryptoServiceProvider();
			//byte[] arrHash=hashSha.ComputeHash(arrByte);
			byte[] arrHash=hashSha.ComputeHash(arrByte);
			//MessageBox.Show(AscEncod.GetString(arrHash,0,arrByte.Length)+"::"+arrHash.Length.ToString());
			return AscEncod.GetString(arrHash,0,arrByte.Length);
 
		}
		public void CreateKey(string strKey )
		{
 
			// 保存密鑰的字節數組
			byte[] arrByte=new byte[8];
			ASCIIEncoding  AscEncod=new ASCIIEncoding();
			int i = 0;
			AscEncod.GetBytes(strKey, i, strKey.Length, arrByte, i);
			// 獲得密碼的Hash值
			SHA1CryptoServiceProvider hashSha=new SHA1CryptoServiceProvider();
			byte[] arrHash=hashSha.ComputeHash(arrByte);
			//將Hash值保存到密鑰
			for(i=0;i<=7;i++)
			{
				TheKey[i] = arrHash[i];
			}
		}
		public void Encrypt(string inName,string outName)
		{
			try
			{	
				// 創建緩沖區
				byte[] storage=new byte[4096];    
				// 已經寫入的字節數量
				long totalBytesWritten= 8; 
				// 每次寫入的字節數量
				int  packageSize=0;
				//聲明文件流
				FileStream  fin=new FileStream(inName, FileMode.Open, FileAccess.Read);
				FileStream  fout=new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
				fout.SetLength(0);
				// 源文件的大小
				long  totalFileLength= fin.Length;
				// 創建加密對象
				DESCryptoServiceProvider des=new DESCryptoServiceProvider();
				CryptoStream  crStream=new CryptoStream(fout,des.CreateEncryptor(TheKey,Vector),CryptoStreamMode.Write);
				//輸出加密后的文件
				while(totalBytesWritten<totalFileLength+8)
				{
					packageSize = fin.Read(storage, 0, 4096);
					crStream.Write(storage, 0, packageSize);
					totalBytesWritten = Convert.ToInt32(totalBytesWritten
						+packageSize);//des.BlockSize * des.BlockSize);
				}
				
				crStream.Close();
				fin.Close();
				fout.Close();
		
			//	MessageBox.Show("fl:"+totalFileLength.ToString()+" tw:"+totalBytesWritten.ToString()+"ps:"+packageSize.ToString());
			}
			catch(Exception e)
			{
			  MessageBox.Show(e.ToString());
						 
			}
		}
		public void Decrypt(string inName,string outName)
		{
			try
			{	
				// 創建緩沖區
				byte[] storage=new byte[4096];    
				// 已經寫入的字節數量
				long totalBytesWritten= 0; 
				// 每次寫入的字節數量
				int  packageSize=0;
				//聲明文件流
				FileStream  fin=new FileStream(inName, FileMode.Open, FileAccess.Read);
				FileStream  fout=new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
				fout.SetLength(0);
				// 源文件的大小
				long  totalFileLength= fin.Length;
				// 創建加密對象
				DESCryptoServiceProvider des=new DESCryptoServiceProvider();
				CryptoStream  crStream=new CryptoStream(fout,des.CreateDecryptor(TheKey,Vector),CryptoStreamMode.Write);
				//輸出加密后的文件
				while(totalBytesWritten<totalFileLength-8)
				{
					packageSize = fin.Read(storage, 0, 4096);
					crStream.Write(storage, 0, packageSize);
					totalBytesWritten = Convert.ToInt32(totalBytesWritten
						+packageSize);//des.BlockSize * des.BlockSize);
			     }
				
				crStream.Close();
				fin.Close();
				fout.Close();
		
					MessageBox.Show("fl:"+totalFileLength.ToString()+" tw:"+totalBytesWritten.ToString()+"ps:"+packageSize.ToString());
			}
			catch(Exception e)
			{
				MessageBox.Show(e.ToString());
						 
			}
		}
	}
}