password_generator.rb

# File: password_generator.rb
# Author: Luke Hubbard
# Gist: http://gist.github.com/21812
# License: MIT

require 'digest'
class PasswordGenerator
  
  CHARS = (('a'..'z').to_a + ('0'..'9').to_a) - %w(i o 0 1 l 0)
  SIZE = 9
  DIGEST = Digest::SHA2
  SALT = ENV['PASSWORD_GENERATOR_SALT'] || "REPLACE ME WITH SOMETHING RANDOM!" 

  def self.random_password(size = SIZE)
    (1..size).collect{|a| CHARS[rand(CHARS.size)] }.join
  end
  
  def self.digest_password(master, instance, size=SIZE, digest=DIGEST, salt=SALT)
    bytes = digest.digest([salt, master, instance]*'|')
    (1..size).to_a.collect{|i| CHARS[ bytes[i] % CHARS.size ] }.join
  end
  
end

# Usage: example creating random password
# puts PasswordGenerator.random_password 
# Usage: example creating digest password
# puts PasswordGenerator.digest_password("my master password","some.domain.name")