/// <summary>
/// 拆包
/// </summary>
/// <param name="buff">源文件字节数组</param>
/// <returns>原始文件字节数组</returns>
public static byte[] Unpackage(byte[] buff)
{
try
{
if (Encoding.UTF8.GetString(buff, 0, _key.Length) != _key)
{
return(null);
}
ulong l = BitConverter.ToUInt64(buff, _key.Length + 19);
byte[] mbuf = new byte[l];
Buffer.BlockCopy(buff, 15 + 19, mbuf, 0, (int)l);
byte[] desbuff = DesByte.Decrypt(mbuf);
byte[] outbuff = new byte[desbuff.Length + buff.Length - 15 - 19 - (int)l];
Buffer.BlockCopy(desbuff, 0, outbuff, 0, desbuff.Length);
Buffer.BlockCopy(buff, 15 + 19 + (int)l, outbuff, desbuff.Length, buff.Length - 15 - 19 - (int)l);
return(outbuff);
}
catch (Exception ex)
{
throw ex;
}
}
