CyberDeck/devise-fido-u2f

class Devise::FidoUsfRegistrationsController < ApplicationController
  before_action :authenticate_resource!

  respond_to :html, :js

  def new
    @registration_requests = u2f.registration_requests
    session[:challenges] = @registration_requests.map(&:challenge)
    key_handles = resource.fido_usf_devices.map(&:key_handle)
    @sign_requests = u2f.authentication_requests(key_handles)
    @app_id = u2f.app_id
    render :new
  end

  # Show a list of all registered devices
  def show
    @devices = resource.fido_usf_devices.all
    render :show
  end

  def destroy
    device = resource.fido_usf_devices.find(params[:id])
    @fade_out_id = device.id unless params[:on_success_redirect_to]
    device.destroy
    unless params[:on_success_redirect_to]
      @devices = resource.fido_usf_devices.all
    end
    flash[:success] = I18n.t('fido_usf.flashs.device.removed')
    respond_to do |format|
      format.js
      format.html { redirect_to fido_usf_registration_url }
    end
  end

  def create
    begin
      response = U2F::RegisterResponse.load_from_json(params[:response])
      reg = u2f.register!(session[:challenges], response)

      pubkey = reg.public_key
      pubkey = Base64.decode64(reg.public_key) unless pubkey.bytesize == 65 && pubkey.byteslice(0) != "\x04"

      @device = FidoUsf::FidoUsfDevice.create!(
        user: resource,
        name: "Token ##{resource.fido_usf_devices.count + 1}",
        certificate: reg.certificate,
        key_handle: reg.key_handle,
        public_key: pubkey,
        counter: reg.counter,
        last_authenticated_at: Time.now
      )
      flash[:success] = I18n.t('fido_usf.flashs.device.registered')
    rescue U2F::Error => e
      @error_message = "Unable to register: #{e.class.name}"
      flash[:error] = @error_message
    ensure
      session.delete(:challenges)
    end

    respond_with resource, location: after_sign_in_path_for(resource)
  end

  def update
    device = resource.fido_usf_devices.find(params[:id])
    device.update!(fido_usf_params)
    respond_to do |format|
      format.js
      format.html { redirect_to fido_usf_registration_url }
    end
  end

  if respond_to?(:helper_method)
    helpers = %w[resource_name]
    helper_method(*helpers)
  end

  protected

  def resource_name
    devise_mapping.name
  end

  def devise_mapping
    @devise_mapping ||= request.env['devise.mapping']
  end

  private

  def fido_usf_params
    # Only allow to update the name
    params.require(:fido_usf_device).permit(:name)
  end

  def u2f
    # use base_url as app_id, e.g. 'http://localhost:3000'
    @u2f ||= U2F::U2F.new(request.base_url)
  end

  def resource
    send("current_#{resource_name}")
  end

  def authenticate_resource!
    send("authenticate_#{resource_name}!")
  end

  def fido_usf_registration_url
    params[:on_success_redirect_to].presence ||
      send("#{resource_name}_fido_usf_registration_url")
  end
end