namespace WhiteRabbit { using System; using System.Collections.Concurrent; using System.Collections.Generic; using System.Configuration; using System.Diagnostics; using System.Linq; using System.Numerics; using System.Security.Cryptography; using System.Text; /// /// Main class /// public static class Program { /// /// Main entry point /// public static void Main() { var stopwatch = new Stopwatch(); stopwatch.Start(); var sourcePhrase = ConfigurationManager.AppSettings["SourcePhrase"]; var sourceChars = ToOrderedChars(sourcePhrase); var maxWordsInPhrase = int.Parse(ConfigurationManager.AppSettings["MaxWordsInPhrase"]); if (sourceChars.Length + maxWordsInPhrase > 27) { Console.WriteLine("Only anagrams of up to 27 characters are allowed"); return; } if (!BitConverter.IsLittleEndian) { Console.WriteLine("Only little-endian systems are supported due to MD5Digest optimizations"); return; } if (IntPtr.Size != 8) { Console.WriteLine("Only 64-bit systems are supported due to MD5Digest optimizations"); } var expectedHashesFirstComponents = ConfigurationManager.AppSettings["ExpectedHashes"] .Split(',') .Select(hash => HexadecimalStringToUnsignedIntArray(hash)[0]) .ToArray(); var processor = new StringsProcessor( Encoding.ASCII.GetBytes(sourcePhrase), maxWordsInPhrase, ReadInput()); Console.WriteLine($"Initialization complete; time from start: {stopwatch.Elapsed}"); #if DEBUG var fastPhrasesCount = processor.GetPhrasesCount(); Console.WriteLine($"Number of phrases: {fastPhrasesCount}; time from start: {stopwatch.Elapsed}"); #endif stopwatch.Restart(); processor.GeneratePhrases() .ForAll(phraseSet => { var hashesFirstComponents = MD5Digest.Compute(phraseSet); for (var i = 0; i < Constants.PhrasesPerSet; i++) { Debug.Assert( sourceChars == ToOrderedChars(ToString(phraseSet, i)), $"StringsProcessor produced incorrect anagram: {ToString(phraseSet, i)}"); if (Array.IndexOf(expectedHashesFirstComponents, hashesFirstComponents[i]) >= 0) { var phrase = ToString(phraseSet, i); var hash = ComputeFullMD5(phrase); Console.WriteLine($"Found phrase for {hash} ({hashesFirstComponents[i]:x8}): {phrase}; time from start is {stopwatch.Elapsed}"); } } }); Console.WriteLine($"Done; time from start: {stopwatch.Elapsed}"); } // Code taken from http://stackoverflow.com/a/321404/831314 private static uint[] HexadecimalStringToUnsignedIntArray(string hex) { return Enumerable.Range(0, hex.Length) .Where(x => x % 8 == 0) .Select(x => ChangeEndianness(hex.Substring(x, 8))) .Select(hexLe => Convert.ToUInt32(hexLe, 16)) .ToArray(); } // We can afford to spend some time here; this code will only run for matched phrases (and for one in several billion non-matched) private static string ComputeFullMD5(string phrase) { var phraseBytes = Encoding.ASCII.GetBytes(phrase); using (var hashAlgorithm = new MD5CryptoServiceProvider()) { var resultBytes = hashAlgorithm.ComputeHash(phraseBytes); return string.Concat(resultBytes.Select(b => b.ToString("x2"))); } } private static string ChangeEndianness(string hex) { return hex.Substring(6, 2) + hex.Substring(4, 2) + hex.Substring(2, 2) + hex.Substring(0, 2); } private static string ToString(PhraseSet phrase, int offset) { return Encoding.ASCII.GetString(phrase.GetBytes(offset)); } private static IEnumerable ReadInput() { string line; while ((line = Console.ReadLine()) != null) { yield return Encoding.ASCII.GetBytes(line); } } private static string ToOrderedChars(string source) { return new string(source.Where(ch => ch != ' ').OrderBy(ch => ch).ToArray()); } #if SINGLE_THREADED private static void ForAll(this IEnumerable source, Action action) { foreach (var entry in source) { action(entry); } } #endif } }