encrypt_decrypt.cs

加密

//************************************************ 
// 功能：加密，解密类
// 作者：蒋伟进
// 日期：2004/4/27
//************************************************
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace AMS.Component
{
	public class Encrypt_Decrypt//Symmetric_encrypt_decrypt_Method
	{
		private SymmetricAlgorithm mobjCryptoService;
		private string Key;
	
		// 对称加密类的构造函数
		public Encrypt_Decrypt()
		{
			mobjCryptoService = new RijndaelManaged();
			//Key = "Guz(%&hj7x89H$yuBI0456FtmaT5&fvHUFCy76*h%(HilJ$lhj!y6&(*jkP87jH7";
			Key = "%%%%%%%%%%%%%%%%&&&&&&&&&&&&&***************";
	
		}
		
		// 获得密钥
		private byte[] GetLegalKey()
		{
			string sTemp = Key;
			mobjCryptoService.GenerateKey();
			byte[] bytTemp = mobjCryptoService.Key;
			int KeyLength = bytTemp.Length;
			if (sTemp.Length > KeyLength)
				sTemp = sTemp.Substring(0, KeyLength);
			else if (sTemp.Length < KeyLength)
				sTemp = sTemp.PadRight(KeyLength, ' ');
			return ASCIIEncoding.ASCII.GetBytes(sTemp);
		}
	
		// 获得初始向量IV
		private byte[] GetLegalIV()
		{
			//string sTemp = "E4ghj*Ghg7!rNIfb&95GUY86GfghUb#er57HBh(u%g6HJ($jhWk7&!hg4ui%$hjk";
			string sTemp = "@@@@@@@@@@@##########!!!!!!!!!!!!!!!";

			mobjCryptoService.GenerateIV();
			byte[] bytTemp = mobjCryptoService.IV;
			int IVLength = bytTemp.Length;
			if (sTemp.Length > IVLength)
				sTemp = sTemp.Substring(0, IVLength);
			else if (sTemp.Length < IVLength)
				sTemp = sTemp.PadRight(IVLength, ' ');
			return ASCIIEncoding.ASCII.GetBytes(sTemp);
		}
	
		//************************************************ 
		//  加密方法
		//  Source：待加密的串
		//  返回经过加密的串
		//************************************************
		public string Encrypto(string Source)
		{
			byte[] bytIn = UTF8Encoding.UTF8.GetBytes(Source);
			MemoryStream ms = new MemoryStream();
			mobjCryptoService.Key = GetLegalKey();
			mobjCryptoService.IV = GetLegalIV();
			ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();
			CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);
			cs.Write(bytIn, 0, bytIn.Length);
			cs.FlushFinalBlock();
			ms.Close();
			byte[] bytOut = ms.ToArray();
			return Convert.ToBase64String(bytOut);
		}
		
		//************************************************ 
		//  解密方法
		//  Source：待解密的串
		//  返回经过解密的串
		//************************************************
		public string Decrypto(string Source)
		{
			byte[] bytIn = Convert.FromBase64String(Source);
			MemoryStream ms = new MemoryStream(bytIn, 0, bytIn.Length);
			mobjCryptoService.Key = GetLegalKey();
			mobjCryptoService.IV = GetLegalIV();
			ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();
			CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
			StreamReader sr = new StreamReader(cs);
			return sr.ReadToEnd();
		}
	}
}