#!/usr/bin/env RBENV_VERSION=1.9.3-preview1 ruby

require "digest"
require "sequel"

module ExpressionEngine
  module Authentication
    ALGORITHMS = {
      32  => Digest::MD5,
      40  => Digest::SHA1,
      64  => Digest::SHA256,
      128 => Digest::SHA512
    }

    def self.algorithm_for(string)
      ALGORITHMS[string.bytesize]
    end
  end

  def self.authenticate(username, password)
    database = Sequel.connect("mysql://...")
    member = database[:exp_members].first(:username => username)
    return false unless member
    algorithm = Authentication.algorithm_for(member[:password])
    raise "Invalid password hash length (#{member[:password]} bytes)" unless algorithm
    algorithm.hexdigest(member[:salt] + password) == member[:password]
  end
end

print "Username: "
username = gets.chomp
print "Password: "
password = gets.chomp

if ExpressionEngine.authenticate(username, password)
  puts "You're authenticated!"
else
  puts "Authentication failed."
end