Adv2016/D05.1/Program.cs

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

namespace D05._1
{
    class Program
    {
        static byte[] ToB(string str) => Encoding.ASCII.GetBytes(str);
        static string ToS(byte[] b) => BitConverter.ToString(b).Replace("-", "");

        static void Main(string[] args)
        {
            if (args.Length < 1) throw new ArgumentException();
            string input = args[0];

            var sb = new StringBuilder();

            using (var md5 = MD5.Create())
            {
                int i = 0;
                while (sb.Length < 8)
                {
                    var h = md5.ComputeHash(ToB($"{input}{i}"));
                    var sh = ToS(h);
                    if (sh.StartsWith("00000")) sb.Append(sh[5]);

                    i++;
                }
            }

            Console.WriteLine($"Password is : {sb.ToString()}");
        }
    }
}