自定义的加密与解密

using System;  
using System.Security.Cryptography;  
using System.IO;  
using System.Text;  
  
class EncryptionAndDissection  
{  
  
    //加密：   
    public static string Encrypting(string strSource)  
    {  
        //把字符串放到byte数组中   
        byte[] bytIn = System.Text.Encoding.Default.GetBytes(strSource);  
        //建立加密对象的密钥和偏移量           
        byte[] iv = { 102, 16, 93, 156, 78, 4, 218, 32 };//定义偏移量   
        byte[] key = { 55, 103, 246, 79, 36, 99, 167, 3 };//定义密钥   
        //实例DES加密类   
        DESCryptoServiceProvider mobjCryptoService = new DESCryptoServiceProvider();  
        mobjCryptoService.Key = iv;  
        mobjCryptoService.IV = key;  
        ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();  
        //实例MemoryStream流加密密文件   
        System.IO.MemoryStream ms = new System.IO.MemoryStream();  
        CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);  
        cs.Write(bytIn, 0, bytIn.Length);  
        cs.FlushFinalBlock();  
        return System.Convert.ToBase64String(ms.ToArray());  
    }  
  
  
    //解密：   
    public static string Decrypting(string Source)  
    {  
        try  
        {  
            //将解密字符串转换成字节数组   
            byte[] bytIn = System.Convert.FromBase64String(Source);  
            //给出解密的密钥和偏移量，密钥和偏移量必须与加密时的密钥和偏移量相同   
            byte[] iv = { 102, 16, 93, 156, 78, 4, 218, 32 };//定义偏移量   
            byte[] key = { 55, 103, 246, 79, 36, 99, 167, 3 };//定义密钥   
            DESCryptoServiceProvider mobjCryptoService = new DESCryptoServiceProvider();  
            mobjCryptoService.Key = iv;  
            mobjCryptoService.IV = key;  
            //实例流进行解密   
            System.IO.MemoryStream ms = new System.IO.MemoryStream(bytIn, 0, bytIn.Length);  
            ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();  
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);  
            StreamReader strd = new StreamReader(cs, Encoding.Default);  
            return strd.ReadToEnd();  
        }  
        catch (Exception ex)  
        {  
            throw new Exception("在文件解密的时候出现错误！错误提示： \n" + ex.Message);  
        }  
    }  
}