bdmac/strong_password

module StrongPassword
  module NistBonusBits
    @@bonus_bits_for_password = {}

    # NIST password strength rules allow up to 6 bonus bits for mixed case and non-alphabetic
    def self.bonus_bits(password)
      @@bonus_bits_for_password[password] ||= begin
        calculate_bonus_bits_for(password)
        end
    end

    # This smells bad as it's only used for testing...
    def self.reset_bonus_cache!
      @@bonus_bits_for_password = {}
    end

    def self.calculate_bonus_bits_for(password)
      upper   = !!(password =~ /[[:upper:]]/)
          lower   = !!(password =~ /[[:lower:]]/)
          numeric = !!(password =~ /[[:digit:]]/)
          other   = !!(password =~ /[^a-zA-Z0-9 ]/)
          space   = !!(password =~ / /)

          # I had this condensed to nested ternaries but that shit was ugly
          bonus_bits = if upper && lower && other && numeric
            6
          elsif upper && lower && other && !numeric
            5
          elsif numeric && other && !upper && !lower
            -2
          elsif numeric && !other && !upper && !lower
            -6
        else
          0
      end

          if !space
            bonus_bits = bonus_bits - 2
          elsif password.split(/\s+/).length > 3
            bonus_bits = bonus_bits + 1
        end
        bonus_bits
      end
  end
end