HackNSlash1.cs

namespace HackNSlash
{
    using System;
    using System.ComponentModel;
    using System.IO;
    using System.Linq;
    using System.Runtime.InteropServices;
    using System.Security.Cryptography;
    using System.Text;
    using System.Text.RegularExpressions;

    class Program
    {
        const string FULL_TEXT = "AND WITH THIS INCANTATION I DO SO ENSORCELL MATTERS SUCH THAT THE"
            + " MAGIC OF THIS APPLICATION PRODUCES A RESULT THAT MUST INVARIABLY"
            + " ENGENDER MAGNIFICENT AMPLIFICATION OF THE DESIRED OUTCOMES THAT "
            + "WE PRODUCE. AND WITH THIS INCANTATION I THEE BOND INTO REALMS FOR"
            + "EVER INTWINING OURSELVES TO OUR COMBINED DESTINIES WHICH PRODUCE "
            + "A KIND OF INFINITE REWARD IN THE CONSTRUCTION OF MECHANISMS TO AI"
            + "D OUR DISCOVERY OF KNOWLEDGE AND TRUTH. AND WITH THIS INCANTATION"
            + " I REVEAL MYSELF TO BE CAPABLE OF CHALLENGES OF THE MIND AND SPIR"
            + "IT WHICH STRENGTHEN AND EMBOLDEN MY CAPACITY FOR TAKING CONTROL O"
            + "VER THAT WHICH WAS ALWAYS OUR BIRTHRIGHT THOUGH SOMESTIMES WE FOO"
            + "L EVEN OURSELVES TO PROTECT THAT WHICH CANNOT BE PROTECTED. WITH "
            + "THIS INCANTATION I OPEN THE LOCK CLASPED SIMPLY TO PROVIDE OPPORT"
            + "UNITY FOR DEMONSTRATION OF MY POWER. AND WITH THIS INCANTATION I "
            + "FOREVER OPEN THE BOUNDARIES OF UNDRESTANDING SUCH THAT I ALWAYS R"
            + "EALIZE THE POWERS I HAVE OVER HIDDEN BUT NOT INACCESSIBLE TRUTHS."
            + " AND WITH THE MECHANISMS OF THIS INCANTATION I CAN BREAK THE BOND"
            + "S THAT WERE NEVER REALLY THERE DESPITE THE INSISTENCE OF THOSE PR"
            + "ESENTING THEMSELVES AS WIZARDS. AND WITH THIS INCANTATION I OBSER"
            + "VE THE FINITE IN THE INFINITE THAT HAS PRODUCED MUCH WONDER AND M"
            + "AGIC IN OUR WORLD AND COMMIT TO THE PURSUITE OF UNDERSTANDING. AN"
            + "D WITH THIS INCANTATION I DO DECLARE THAT BIRTHRIGHT HAS NO STAND"
            + "ING IN THE CHAMBERS OF WISDOM. AND WITH THIS INCANTATION I DO PRE"
            + "SENT MATTERS SUCH THAT IT IS OBSERVABLE THAT NO CREATURE SHOULD B"
            + "E RESTRAINED BY THE FEAR OF OTHERS.";

        const int SUBSTRING_LEN = 4;

        static string CreateSentence(byte[] uid)
        {
            var result = FULL_TEXT.Substring(0, SUBSTRING_LEN);
            var uidBytesUsed = 0;
            int afterLastMatch;
            do
            {
                var xorFromUid = uid.Skip(uidBytesUsed).Take(2).Aggregate(0, (a, b) => a ^ b);

                var last4Chars = result.Substring(result.Length - SUBSTRING_LEN);
                var matches = new Regex(Regex.Escape(last4Chars)).Matches(FULL_TEXT);
                var numberOfOccurences = matches.Count;

                var match = matches[xorFromUid % matches.Count];

                result += FULL_TEXT.Substring(match.Index + SUBSTRING_LEN, SUBSTRING_LEN);
                afterLastMatch = match.Index + SUBSTRING_LEN*2;

                uidBytesUsed += 2;
            } while (uidBytesUsed < uid.Length);

            if (!result.EndsWith("."))
            {
                var charsToAdd = FULL_TEXT.Substring(afterLastMatch).TakeWhile(c => c != '.');
                result += new string(charsToAdd.ToArray()) + ".";
            }

            return result;
        }

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern bool GetVolumeNameForVolumeMountPoint(string lpszVolumeMountPoint, StringBuilder lpszVolumeName, uint cchBufferLength);

        static string GetVolumeNameForVolumeMountPoint(string lpszVolumeMountPoint)
        {
            var lpszVolumeName = new StringBuilder(50);
            var apiResult = GetVolumeNameForVolumeMountPoint(lpszVolumeMountPoint,lpszVolumeName, (uint)(lpszVolumeName.Capacity + 1));
            if (!apiResult)
            {
                throw new Win32Exception();
            }

            return lpszVolumeName.ToString();
        }

        static byte[] GetUniqueId()
        {
            var winDir = Environment.GetFolderPath(Environment.SpecialFolder.Windows);
            var winDrive = Path.GetPathRoot(winDir);
            var mountPoint = GetVolumeNameForVolumeMountPoint(winDrive);

            var sha1 = new SHA1CryptoServiceProvider();
            sha1.Initialize();
            return sha1.ComputeHash(Encoding.ASCII.GetBytes(mountPoint));
        }

        static void Main()
        {
            var uid = GetUniqueId();
            Console.WriteLine(CreateSentence(uid));
            Console.ReadLine();
        }
    }
}