login_controller.rb

class LoginController < ApplicationController
  skip_before_filter :check_authentication, :only => :index

  def index
    user = User.find_by_email(params[:email])
    if user and user.authenticate(params[:password])
      respond_with user
    end
  end  
  
  private
  def login_params
    params.require(:login).permit(:email, :password)
  end
end