C#使用RSA加密解密文件

//加密代码，注意会覆盖原文件，里面有我的公钥，你要用时记得覆盖我的公钥 private bool  encryptFile(string filename)    {      FileStream f;      try      {        f = new FileStream(filename, FileMode.Open, FileAccess.ReadWrite, FileShare.Read);      }      catch      {        return false;      }      Random r = new Random();      Thread.Sleep(10*r.Next(3,8));      RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(1024);      rsa.FromXmlString("<RSAKeyValue><Modulus>w7nNT8U7kwTw8UqLk0lROxmfTRZnQrMH1QrNyUGtoeAJ3w+iH08j+h83cPWxwPoxpXm1cgCLFWtCFWY1rkQDCCLxJhUIwYTbGKTg9h0uUVfNxGiNji7dcHShd01UYpZjHCwOar1wjJD4vJqVJCk++59UUMhE9IUATuSUVpRy1bE=</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>");      //导入密钥      byte[] data = new byte[16];      ArrayList con = new ArrayList();      while(f.Read(data, 0, 16)!=0)      {        byte[] result = rsa.Encrypt(data,false);        //Thread.Sleep(10 * r.Next(2, 7));        con.Add(result);      }      //加密      f.Seek(0, SeekOrigin.Begin);      foreach(byte[] d in con)      {        f.Write(d, 0, d.Length);      }      f.Close();      return true;}

//解密代码，覆盖原文件，返回值表示是否解密成功 private bool decryptFile(string filename,string key)    {      FileStream f;      try      {        f = new FileStream(filename, FileMode.Open, FileAccess.ReadWrite, FileShare.Read);      }      catch      {        return false;      }      RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(1024);      try      {        rsa.FromXmlString(key);      }      catch      {        return false;      }      byte[] data = new byte[128];      ArrayList con = new ArrayList();      while (f.Read(data, 0, 128) != 0)      {        byte[] result;        try        {          result = rsa.Decrypt(data, false);        }        catch        {          return false;        }        con.Add(result);      }      //解密      f.SetLength(con.Count * 16);      f.Seek(0, SeekOrigin.Begin);      foreach (byte[] d in con)      {        f.Write(d, 0, d.Length);      }      f.Close();      return true;}