SetDateTime64 Overflow Exception

[TGibsonReach]

Passing in a time >= year 2037 to function:
void SetDateTime64(int offset, DateTime? value) { SetUInt64BE(offset, value == null ? 0 : Convert.ToUInt64((value.Value.Ticks - epoch.Ticks) * (0.0000001 * (1L << 32)))); }
causes the conversion to UInt64 to overflow.

Test Program:

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            DateTime EpochFuture = new DateTime(2037, 1, 1);
            DateTime EpochPast = new DateTime(1900, 1, 1);
            try
            {
                UInt64 Result = Convert.ToUInt64((EpochFuture.Ticks - EpochPast.Ticks) * (0.0000001 * (1L << 32)));
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }
    }
}

Output:
System.OverflowException: Arithmetic operation resulted in an overflow.
at System.Convert.ToUInt64(Double value)
at ConsoleApp1.Program.Main(String[] args) in MyProgram

[DamianMorozov]

What are you doing? It is not NtpClient's methods.

[TGibsonReach]

NtpPacket.cs contains the inline function which is used when setting several of the packet variables?

void SetDateTime64(int offset, DateTime? value) 
{ 
       SetUInt64BE(offset, value == null ? 0 : Convert.ToUInt64((value.Value.Ticks - epoch.Ticks) * (0.0000001 * (1L << 32)))); 
}

[robertvazan]

I can confirm that GuerrillaNtp is not Y2038 safe. It needs to implement correct rollover.

[robertvazan]

This is actually Y2036 bug, not Y2038 bug. I have fixed the library. The fix will be included in 3.0 release that is coming in the next few days.