using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace Common.system
{
    public class DataProvider
    {
        ///3DES解密   
        public static string TripleDesDecrypt(string pToDecrypt, string sKey)
        {
            sKey = sKey.Substring(0, 24);
            TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider { Mode = CipherMode.ECB, Padding = PaddingMode.Zeros };
            byte[] inputByteArray = new byte[pToDecrypt.Length / 2];
            for (int x = 0; x < pToDecrypt.Length / 2; x++)
            {
                int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));
                inputByteArray[x] = (byte)i;
            }
            des.Key = Encoding.ASCII.GetBytes(sKey);
            des.IV = new byte[]
            {
                0,
                00,
                00,
                00,
                00,
                00,
                00,
                00,
            };
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            return System.Text.Encoding.Default.GetString(ms.ToArray()).Replace("\0", "");
        }

        /// <summary>
        /// 返回一个时间戳到秒
        /// </summary>
        /// <returns></returns>
        public static long TimestampTotalSeconds()
        {
            TimeSpan ts = DateTime.UtcNow -
            new DateTime(
                1970,
                1,
                1,
                0,
                0,
                0,
                0
            );
            long timestr = Convert.ToInt64(ts.TotalSeconds);
            return timestr;
        }
    }
}