class HelpController < ApplicationController layout 'help' def index end def show @category = clean_path_info(path_params[:category]) @file = path_params[:file] respond_to do |format| format.any(:markdown, :md, :html) do path = Rails.root.join('doc', @category, "#{@file}.md") if File.exist?(path) @markdown = File.read(path) render 'show.html.haml' else # Force template to Haml render 'errors/not_found.html.haml', layout: 'errors', status: 404 end end # Allow access to images in the doc folder format.any(:png, :gif, :jpeg) do path = Rails.root.join('doc', @category, "#{@file}.#{params[:format]}") if File.exist?(path) send_file(path, disposition: 'inline') else head :not_found end end # Any other format we don't recognize, just respond 404 format.any { head :not_found } end end def shortcuts end def ui end private def path_params params.require(:category) params.require(:file) params end PATH_SEPS = Regexp.union(*[::File::SEPARATOR, ::File::ALT_SEPARATOR].compact) # Taken from ActionDispatch::FileHandler # Cleans up the path, to prevent directory traversal outside the doc folder. def clean_path_info(path_info) parts = path_info.split(PATH_SEPS) clean = [] # Walk over each part of the path parts.each do |part| # Turn `one//two` or `one/./two` into `one/two`. next if part.empty? || part == '.' if part == '..' # Turn `one/two/../` into `one` clean.pop else # Add simple folder names to the clean path. clean << part end end # If the path was an absolute path (i.e. `/` or `/one/two`), # add `/` to the front of the clean path. clean.unshift '/' if parts.empty? || parts.first.empty? # Join all the clean path parts by the path separator. ::File.join(*clean) end end