Parallel brute force

Parallel brute force is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Task

Find, through brute force, the five-letter passwords corresponding with the following SHA256 hashes:

1. 1115dd800feaacefdf481f1f9070374a2a81e27880f187396db67958b207cbad
2. 3a7bd3e2360a3d29eea436fcfb7e44c735d117c42d1c1835420b6b9942dd4f1b
3. 74e1bb62f8dabb8125a58852b63bdf6eaef667cb56ac7f7cdba6d7305c50a22f

Your program should naively iterate through all possible passwords consisting only of five lower-case ASCII English letters. It should use concurrent or parallel processing, if your language supports that feature. You may calculate SHA256 hashes by calling a library or through a custom implementation. Print each matching password, along with its SHA256 value. Optionally, measure how long your program takes to run, and print that time.

C#

  <lang csharp>using System; using System.Linq; using System.Security.Cryptography; using System.Text; using System.Threading.Tasks;

class Program {

   static void Main(string[] args)
   {
       byte[] one = StringHashToByteArray("1115dd800feaacefdf481f1f9070374a2a81e27880f187396db67958b207cbad");
       byte[] two = StringHashToByteArray("3a7bd3e2360a3d29eea436fcfb7e44c735d117c42d1c1835420b6b9942dd4f1b");
       byte[] three = StringHashToByteArray("74e1bb62f8dabb8125a58852b63bdf6eaef667cb56ac7f7cdba6d7305c50a22f");
       var prey = new byte[][] { one, two, three };
       var dt = DateTime.Now;
       int chunksize = 26 * 26 * 26 * 26 * 26 / Environment.ProcessorCount;
       Task[] tasks = (
                       from i in Enumerable.Range(0, Environment.ProcessorCount)
                       select Task.Run(() => MatchesInRange(i * chunksize, (i + 1) * chunksize - 1, prey))
                     ).ToArray();
       Task.WaitAll(tasks);
       Console.WriteLine((DateTime.Now - dt).TotalMilliseconds + " milliseconds elapsed.");
   }
   static byte[] StringHashToByteArray(string s)
   {
       return Enumerable.Range(0, s.Length / 2).Select(i => (byte)Convert.ToInt16(s.Substring(i * 2, 2), 16)).ToArray();
   }

   static void MatchesInRange(int start, int stop, byte[][] prey)
   {
       byte[] letters = new byte[5];
       byte[] hash;
       int serial;
       var shaFactory = new SHA256Managed();
       for (int seriali = start; seriali <= stop; seriali++)
       {
           serial = seriali;
           int divisor = 456976; // 26 * 26 * 26 * 26;
           for (int i = 0; i < 5; i++)
           {
               letters[i] = (byte)(97 + Math.DivRem(serial, divisor, out serial));
               divisor /= 26;
           }
           hash = shaFactory.ComputeHash(letters);
           if (hash[0] == prey[0][0] || hash[0] == prey[1][0] || hash[0] == prey[2][0])
           {
               if (Enumerable.SequenceEqual(hash, prey[0]) || Enumerable.SequenceEqual(hash, prey[1]) || Enumerable.SequenceEqual(hash, prey[2]))
               {
                   Console.WriteLine(Encoding.ASCII.GetString(letters) + " => " + BitConverter.ToString(hash).ToLower().Replace("-", ""));
               }
           }
       }
   }

}</lang>

Output:

apple => 3a7bd3e2360a3d29eea436fcfb7e44c735d117c42d1c1835420b6b9942dd4f1b
mmmmm => 74e1bb62f8dabb8125a58852b63bdf6eaef667cb56ac7f7cdba6d7305c50a22f
zyzzx => 1115dd800feaacefdf481f1f9070374a2a81e27880f187396db67958b207cbad