require 'active_support/core_ext/object/try' require 'action_view/helpers/sanitize_helper/sanitizers' module ActionView # = Action View Sanitize Helpers module Helpers # The SanitizeHelper module provides a set of methods for scrubbing text of undesired HTML elements. # These helper methods extend Action View making them callable within your template files. module SanitizeHelper extend ActiveSupport::Concern # This +sanitize+ helper will html encode all tags and strip all attributes that # aren't specifically allowed. # # It also strips href/src tags with invalid protocols, like javascript: especially. # It does its best to counter any tricks that hackers may use, like throwing in # unicode/ascii/hex values to get past the javascript: filters. Check out # the extensive test suite. # # <%= sanitize @article.body %> # # You can add or remove tags/attributes if you want to customize it a bit. # See ActionView::Base for full docs on the available options. You can add # tags/attributes for single uses of +sanitize+ by passing either the # :attributes or :tags options: # # Normal Use # # <%= sanitize @article.body %> # # Custom Use - Custom Scrubber # (supply a Loofah::Scrubber that does the sanitization) # # scrubber can either wrap a block: # scrubber = Loofah::Scrubber.new do |node| # node.text = "dawn of cats" # end # # or be a subclass of Loofah::Scrubber which responds to scrub: # class KittyApocalypse < Loofah::Scrubber # def scrub(node) # node.text = "dawn of cats" # end # end # scrubber = KittyApocalypse.new # # <%= sanitize @article.body, scrubber: scrubber %> # # A custom scrubber takes precedence over custom tags and attributes # Learn more about scrubbers here: https://github.com/flavorjones/loofah # # Custom Use - tags and attributes # (only the mentioned tags and attributes are allowed, nothing else) # # <%= sanitize @article.body, tags: %w(table tr td), attributes: %w(id class style) %> # # Add table tags to the default allowed tags # # class Application < Rails::Application # config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td' # end # # Remove tags to the default allowed tags # # class Application < Rails::Application # config.after_initialize do # ActionView::Base.sanitized_allowed_tags.delete 'div' # end # end # # Change allowed default attributes # # class Application < Rails::Application # config.action_view.sanitized_allowed_attributes = ['id', 'class', 'style'] # end # # Please note that sanitizing user-provided text does not guarantee that the # resulting markup is valid (conforming to a document type) or even well-formed. # The output may still contain e.g. unescaped '<', '>', '&' characters and # confuse browsers. # def sanitize(html, options = {}) self.class.white_list_sanitizer.sanitize(html, options).try(:html_safe) end # Sanitizes a block of CSS code. Used by +sanitize+ when it comes across a style attribute. def sanitize_css(style) self.class.white_list_sanitizer.sanitize_css(style) end # Strips all HTML tags from the +html+, including comments. This uses # Nokogiri for tokenization (via Loofah) and so its HTML parsing ability # is limited by that of Nokogiri. # # strip_tags("Strip these tags!") # # => Strip these tags! # # strip_tags("Bold no more! See more here...") # # => Bold no more! See more here... # # strip_tags("
Welcome to my website!
") # # => Welcome to my website! def strip_tags(html) self.class.full_sanitizer.sanitize(html) end # Strips all link tags from +text+ leaving just the link text. # # strip_links('Ruby on Rails') # # => Ruby on Rails # # strip_links('Please e-mail me at me@email.com.') # # => Please e-mail me at me@email.com. # # strip_links('Blog: Visit.') # # => Blog: Visit. def strip_links(html) self.class.link_sanitizer.sanitize(html) end module ClassMethods #:nodoc: attr_writer :full_sanitizer, :link_sanitizer, :white_list_sanitizer def sanitized_protocol_separator white_list_sanitizer.protocol_separator end def sanitized_uri_attributes white_list_sanitizer.uri_attributes end def sanitized_bad_tags white_list_sanitizer.bad_tags end def sanitized_allowed_tags white_list_sanitizer.allowed_tags end def sanitized_allowed_attributes white_list_sanitizer.allowed_attributes end def sanitized_allowed_css_properties white_list_sanitizer.allowed_css_properties end def sanitized_allowed_css_keywords white_list_sanitizer.allowed_css_keywords end def sanitized_shorthand_css_properties white_list_sanitizer.shorthand_css_properties end def sanitized_allowed_protocols white_list_sanitizer.allowed_protocols end # Gets the ActionView::FullSanitizer instance used by +strip_tags+. Replace with # any object that responds to +sanitize+. # # class Application < Rails::Application # config.action_view.full_sanitizer = MySpecialSanitizer.new # end # def full_sanitizer @full_sanitizer ||= ActionView::FullSanitizer.new end # Gets the ActionView::LinkSanitizer instance used by +strip_links+. # Replace with any object that responds to +sanitize+. # # class Application < Rails::Application # config.action_view.link_sanitizer = MySpecialSanitizer.new # end # def link_sanitizer @link_sanitizer ||= ActionView::LinkSanitizer.new end # Gets the ActionView::WhiteListSanitizer instance used by sanitize and +sanitize_css+. # Replace with any object that responds to +sanitize+. # # class Application < Rails::Application # config.action_view.white_list_sanitizer = MySpecialSanitizer.new # end # def white_list_sanitizer @white_list_sanitizer ||= ActionView::WhiteListSanitizer.new end def sanitized_protocol_separator=(value) ActionView::WhiteListSanitizer.protocol_separator = value end # Adds valid HTML attributes that the +sanitize+ helper checks for URIs. # # class Application < Rails::Application # config.action_view.sanitized_uri_attributes = 'lowsrc', 'target' # end # def sanitized_uri_attributes=(attributes) ActionView::WhiteListSanitizer.update_uri_attributes(attributes) end # Adds to the Set of 'bad' tags for the +sanitize+ helper. # # class Application < Rails::Application # config.action_view.sanitized_bad_tags = 'embed', 'object' # end # def sanitized_bad_tags=(attributes) ActionView::WhiteListSanitizer.bad_tags = attributes end # Adds to the Set of allowed tags for the +sanitize+ helper. # # class Application < Rails::Application # config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td' # end # def sanitized_allowed_tags=(attributes) ActionView::WhiteListSanitizer.update_allowed_tags(attributes) end # Adds to the Set of allowed HTML attributes for the +sanitize+ helper. # # class Application < Rails::Application # config.action_view.sanitized_allowed_attributes = ['onclick', 'longdesc'] # end # def sanitized_allowed_attributes=(attributes) ActionView::WhiteListSanitizer.update_allowed_attributes(attributes) end # Adds to the Set of allowed CSS properties for the #sanitize and +sanitize_css+ helpers. # # class Application < Rails::Application # config.action_view.sanitized_allowed_css_properties = 'expression' # end # def sanitized_allowed_css_properties=(attributes) ActionView::WhiteListSanitizer.update_allowed_css_properties(attributes) end # Adds to the Set of allowed CSS keywords for the +sanitize+ and +sanitize_css+ helpers. # # class Application < Rails::Application # config.action_view.sanitized_allowed_css_keywords = 'expression' # end # def sanitized_allowed_css_keywords=(attributes) ActionView::WhiteListSanitizer.update_allowed_css_keywords(attributes) end # Adds to the Set of allowed shorthand CSS properties for the +sanitize+ and +sanitize_css+ helpers. # # class Application < Rails::Application # config.action_view.sanitized_shorthand_css_properties = 'expression' # end # def sanitized_shorthand_css_properties=(attributes) ActionView::WhiteListSanitizer.update_shorthand_css_properties(attributes) end # Adds to the Set of allowed protocols for the +sanitize+ helper. # # class Application < Rails::Application # config.action_view.sanitized_allowed_protocols = 'ssh', 'feed' # end # def sanitized_allowed_protocols=(attributes) ActionView::WhiteListSanitizer.update_allowed_protocols(attributes) end end end end end