using?System;
using?System.Collections.Generic;
using?System.Text;
using?System.Security.Cryptography;
using?System.IO;

//?對稱加密幫助方法
public?class?CryptoHelper?{

	//?對稱加密算法提供器
	private?ICryptoTransform?encryptor;		//?加密器對象
	private?ICryptoTransform?decryptor;		//?解密器對象
	private?const?int?BufferSize?=?1024;

	public?CryptoHelper（string?algorithmName?string?key）?{
		SymmetricAlgorithm?provider?=?SymmetricAlgorithm.Create（algorithmName）;
		provider.Key?=?Encoding.UTF8.GetBytes（key）;
		provider.IV?=?new?byte[]?{?0x12?0x34?0x56?0x78?0x90?0xAB?0xCD?0xEF?};

		encryptor?=?provider.CreateEncryptor（）;
		decryptor?=?provider.CreateDecryptor（）;
	}

	public?CryptoHelper（string?key）?:?this（“TripleDES“?key）?{?}

	//?加密算法
	public?string?Encrypt（string?clearText）?{
		//?創建明文流
		byte[]?clearBuffer?=?Encoding.UTF8.GetBytes（clearText）;
		MemoryStream?clearStream?=?new?MemoryStream（clearBuffer）;

		//?創建空的密文流
		MemoryStream?encryptedStream?=?new?MemoryStream（）;

		CryptoStream?cryptoStream?=
			new?CryptoStream（encryptedStream?encryptor?CryptoStreamMode.Write）;

		//?將明文流寫入到buffer中
		//?將buffer中的數據寫入到cryptoStream中
		int?bytesRead?=?0;
		byte[]?buffer?=?new?byte[BufferSize];
		do?{
			bytesRead?=?clearStream.Read（buffer?0?BufferSize）;
			cryptoStream.Write（buffer?0?bytesRead）;
		}?while?（bytesRead?>?0）;

		cryptoStream.FlushFinalBlock（）;

		//?獲取加密后的文本
		buffer?=?encryptedStream.ToArray（）;
		string?encryptedText?=?Convert.Tobase64String（buffer）;
		return?encryptedText;
	}

	//?解密算法
	public?string?Decrypt（string?encryptedText）?{
		byte[]?encryptedBuffer?=?Convert.Frombase64String（encryptedText）;
		Stream?encryptedStream?=?new?MemoryStream（encryptedBuffer）;

		MemoryStream?clearStream?=?new?MemoryStream（）;
		CryptoStream?cryptoStream?=
			new?CryptoStream（encryptedStream?decryptor?CryptoStreamMode.Read）;

		int?bytesRead?=?0;
		byte[]?buffer?=?new?byte[BufferSize];

		do?{
			bytesRead?=?cryptoStream.Read（buffer?0?BufferSize）;
			clearStream.Write（buffer?0?bytesRead）;
		}?while?（bytesRead?>?0）;

		buffer?=?clearStream.GetBuffer（）;
		string?clearText?=
			Encoding.UTF8.GetString（buffer?0?（int）clearStream.Length）;

		return?clearText;
	}

	public?static?string?Encrypt（string?clearText?string?key）?{
		CryptoHelper?helper?=?new?CryptoHelper（key）;
		return?helper.Encrypt（clearText）;
	}

	public?static?string?Decrypt（string?encryptedText?string?key）?{
		CryptoHelper?helper?=?new?CryptoHelper（key）;
		return?helper.Decrypt（encryptedText）;
	}
}


namespace?ConsoleApp?{

	class?Program?{

		static?void?Main（string[]?args）?{
			string?key?=?“ABCDEFGHIJKLMNOP“;
			string?clearText?=?“歡迎訪問www.tracefact.net“;

			CryptoHelper?helper?=?new?CryptoHelper（key）;
			
			string?encryptedText?=?helper.Encrypt（clearText）;
			Console.WriteLine（encryptedText）;

			clearText?=?helper.Decrypt（encryptedText）;
			Console.WriteLine（clearText）;
		}
		
	}
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????6144??2008-10-22?23:41??ConsoleApp\bin\Debug\ConsoleApp.exe

?????文件??????15872??2008-10-22?23:41??ConsoleApp\bin\Debug\ConsoleApp.pdb

?????文件??????14328??2008-10-22?16:50??ConsoleApp\bin\Debug\ConsoleApp.vshost.exe

?????文件???????2114??2008-10-22?23:41??ConsoleApp\ConsoleApp.csproj

?????文件????????168??2008-10-22?16:24??ConsoleApp\ConsoleApp.csproj.user

?????文件????????331??2008-10-22?20:46??ConsoleApp\obj\Debug\ConsoleApp.csproj.FileListAbsolute.txt

?????文件???????6144??2008-10-22?23:41??ConsoleApp\obj\Debug\ConsoleApp.exe

?????文件??????15872??2008-10-22?23:41??ConsoleApp\obj\Debug\ConsoleApp.pdb

?????文件???????3144??2008-10-22?23:41??ConsoleApp\Program.cs

?????文件???????1352??2008-10-09?11:19??ConsoleApp\Properties\AssemblyInfo.cs

?????文件????????920??2008-10-09?11:19??Cryptography.sln

?????目錄??????????0??2008-10-09?12:19??ConsoleApp\obj\Debug\Refactor

?????目錄??????????0??2008-10-09?11:19??ConsoleApp\obj\Debug\TempPE

?????目錄??????????0??2008-10-22?16:27??ConsoleApp\bin\Debug

?????目錄??????????0??2008-10-22?23:41??ConsoleApp\obj\Debug

?????目錄??????????0??2008-10-22?16:19??ConsoleApp\bin

?????目錄??????????0??2008-10-09?11:19??ConsoleApp\obj

?????目錄??????????0??2008-10-09?11:19??ConsoleApp\Properties

?????目錄??????????0??2008-10-22?23:41??ConsoleApp

?????文件????????329??2008-10-22?23:43??ReadMe.txt

-----------?---------??----------?-----??----

????????????????66718????????????????????20