engineyard-guesser.rb

require 'rubygems'
require 'amatch'
require 'digest/sha1'

#data structs
REF_SHA = Digest::SHA1.hexdigest('I would much rather hear more about your whittling project')
DICT = File.read('mydict.txt').map { |x| x.chomp }
ALPHA = (('A'..'Z').to_a << ('a'..'z').to_a).flatten
HAM = Amatch::Hamming.new(REF_SHA)

def produce_sentence
  (1..rand(28)).map { DICT[rand(1000)] }.join(' ')
end

def permute(str)
  str.split('').map do |a| 
    decision = rand(2)
    if decision == 1
      a.upcase
    else
      a.downcase
    end
  end.join('') + salt.to_s
end

def salt
  (1..rand(5)).map { ALPHA[rand(52)] }
end

File.open(Time.now.to_i.to_s + '.txt', 'w') do |f| 
  loop do 
    string = permute(produce_sentence)
    sha = Digest::SHA1.hexdigest(permute(produce_sentence))
    distance = HAM.match(sha)
    if distance < 29
      f.puts "#{distance}::#{string}"
      f.flush
    end
  end
end