brute.cs

using System;
using System.Linq;
using System.Threading.Tasks;

namespace BruteMission004
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var mission = new Mission004();
            mission.Brute();
            Console.WriteLine(mission.Check(new byte[] { 0x47, 0xA8, 0x47, 0x57, 0xDE })); // disconnect3d
            Console.WriteLine(mission.Check(new byte[] { 0x47, 0x57, 0x47, 0x57, 0x21 }));
            mission.Brute(0, 255);
            Console.ReadLine();
        }
    }

    internal class Mission004
    {
        private const UInt64 magicValue = 0x1451723121264133;

        internal bool Check(byte[] chars)
        {
            UInt64 ch = magicValue;

            for (int i = 0; i < 5; i++)
                ch = ((ch << 9) | (ch >> 55)) ^ chars[i];

            return 14422328074577807877 == ch;
        }

        internal void Brute(int startValue = 32, int stopValue = 128)
        {
            Parallel.For(startValue, stopValue, (i) =>
            {
                byte[] chars = new byte[5];
                chars[0] = (byte)i;
                for (int j = startValue; j < stopValue; j++)
                {
                    chars[1] = (byte)j;
                    for (int k = startValue; k < stopValue; k++)
                    {
                        chars[2] = (byte)k;
                        for (int l = startValue; l < stopValue; l++)
                        {
                            chars[3] = (byte)l;
                            for (int m = startValue; m < stopValue; m++)
                            {
                                chars[4] = (byte)m;
                                if (Check(chars))
                                    lock (this)
                                    {
                                        Console.WriteLine(string.Join(" ", chars.Select(c => String.Format("0x{0:X}", (int)c))));
                                    }
                            }
                        }
                    }
                }
            });
        }
    }
}