/// <summary>
/// 把指定的已经加密的并且可以通过Url传递的字符串解密
/// </summary>
/// <param name="encryptedUrlString"></param>
/// <param name="validateTimestamp">是否验证时间戳</param>
/// <param name="allowDelayTicks"></param>
/// <returns></returns>
private static string DecryptUrlString(string encryptedUrlString, bool validateTimestamp, long allowDelayTicks)
{
string result = HttpUtility.UrlDecode(encryptedUrlString);
result = EncodingUtility.ToGb2312StringFromBase64(result);
result = DecryptByTriple(result);
//如果用户没有传入数据，则直接忽略
if (result.Trim() == string.Empty)
{
return(result);
}
//现在都携带了时间戳，需要把时间戳去掉
if (result.IndexOf("-", StringComparison.Ordinal) == -1)
{
throw new Exception("需要解密的字符串格式不正确");
}
string rawTicks = result.Substring(0, result.IndexOf("-", StringComparison.Ordinal));
long lRawTicks;
if (!long.TryParse(rawTicks, out lRawTicks))
{
throw new Exception("需要解密的字符串格式不正确");
}
if (validateTimestamp && allowDelayTicks > 0)
{
long factDelayTicks = DateTime.Now.Ticks - lRawTicks;
if (factDelayTicks > allowDelayTicks)
{
throw new Exception("需要解密的字符串数据不正确");
}
}
return(result.Remove(0, result.IndexOf("-", StringComparison.Ordinal) + 1));
}