gistfile1.rb

  def login_required
    if session[:user_id]
      @user ||= User.find(session[:user_id])
      @access_token ||= OAuth::AccessToken.new(get_consumer, @user.oauth_token, @user.oauth_secret)
    else
      redirect_to :controller => 'session', :action => 'new'
    end
  end

  def get_consumer
    require 'oauth/consumer'
    require 'oauth/signature/rsa/sha1'
     consumer = OAuth::Consumer.new(CONSUMER_KEY,CONSUMER_SECRET,
    {
    :site => "https://www.google.com",
    :request_token_path => "/accounts/OAuthGetRequestToken",
    :access_token_path => "/accounts/OAuthGetAccessToken",
    :authorize_path=> "/accounts/OAuthAuthorizeToken",
    :signature_method => "RSA-SHA1",
    :private_key_file => PATH_TO_PRIVATE_KEY})
  end