passwerd.rb

#!/usr/bin/env ruby

class Passwerd
  CHARSETS = {
    lower: (?a..?z).to_a,
    upper: (?A..?Z).to_a,
    number: (?0..?9).to_a,
    space: [' '],
    sym1: (?!..?/).to_a,
    sym2: (?:..?@).to_a,
    sym3: (?[..?`).to_a,
    sym4: (?{..?~).to_a
  }

  def self.usage
    warn "usage: #{$0} password_candidate"
  end

  def initialize candidate
    @candidate = candidate
  end
  attr :candidate

  def debug text=?\n
    if $VERBOSE | $DEBUG then
      warn text
    end
  end

  def calculate1
    charset = Array.new

    len = 0

    candidate.each_char do |char|
      len += 1
      debug "character: #{char}"

      CHARSETS.each do |name, chars|
        if chars.include? char then
          charset = charset | chars
          debug "char type: #{name}"
        end
      end

      debug "length: #{len}"
      debug "entropy: #{(Math.log2(charset.length)*len).round(2)}"
      debug
    end

    puts "length: #{candidate.length}"
    debug "charset: #{charset.inspect}"
    puts "entropy: #{(Math.log2(charset.length)*candidate.length).round(2)}"
  end

  def calculate2
    charset = Array.new

    candidate.each_char do |char|
      charset = charset | [char]
    end

    puts "length: #{candidate.length}"
    debug "charset: #{charset.inspect}"
    puts "entropy: #{(Math.log2(charset.length)*candidate.length).round(2)}"
  end
end

if ARGV[0] then
  p = Passwerd.new ARGV[0]
  p.calculate2
else
  warn "no password candidate provided"
  Passwerd.usage
  exit 1
end