Simple Sinatra Authentication

app.rb

require 'rubygems'
require 'sinatra'

set :username,'Bond'
set :token,'shakenN0tstirr3d'
set :password,'007'

helpers do
  def admin? ; request.cookies[settings.username] == settings.token ; end
  def protected! ; halt [ 401, 'Not Authorized' ] unless admin? ; end
end

get '/' do
  haml :index
end

get('/admin'){ haml :admin }

post '/login' do
  if params['username']==settings.username&&params['password']==settings.password
    response.set_cookie(settings.username,settings.token) 
    redirect '/'
  else
    "Username or Password incorrect"
  end
end

get('/logout'){ response.set_cookie(settings.username, false) ; redirect '/' }

get '/public' do
  'Anyone can see this'
end

get '/private' do
  protected!
  'For Your Eyes Only!'
end

__END__
@@layout
!!! 5
%html
  %head
    %meta(charset="utf-8")
    %title Really Simple Authentication
  %body
    %a(href='/admin')Login
    %a(href='/logout')Logout
    %a(href='/public')Public
    %a(href='/private')Private
    = yield
@@admin
%form(action="/login" method="post")
  %label(for="username")Username:
  %input#username(type="text" name="username")
  %label(for="password")Password:
  %input#password(type="password" name="password")
  %input(type="submit" value="Login") or <a href="/">Cancel</a>
@@index
-if admin?
  %h1 Welcome 007!
-else
  %h1 Welcome!

From http://ididitmyway.heroku.com/past/2011/2/22/really_simple_authentication_in_sinatra/