diff options
| -rw-r--r-- | actionview/lib/action_view/helpers/sanitize_helper.rb | 127 |
1 files changed, 51 insertions, 76 deletions
diff --git a/actionview/lib/action_view/helpers/sanitize_helper.rb b/actionview/lib/action_view/helpers/sanitize_helper.rb index e72e85ee5f..463a4e9f60 100644 --- a/actionview/lib/action_view/helpers/sanitize_helper.rb +++ b/actionview/lib/action_view/helpers/sanitize_helper.rb @@ -8,76 +8,77 @@ module ActionView # 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. + # Sanitizes HTML input, stripping all tags and attributes that aren't whitelisted. # - # 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. + # It also strips href/src attributes with unsafe protocols like + # <tt>javascript:</tt>, while also protecting against attempts to use Unicode, + # ASCII, and hex character references to work around these protocol filters. # - # <%= sanitize @article.body %> + # The default sanitizer is Rails::Html::WhiteListSanitizer. See {Rails HTML + # Sanitizers}[https://github.com/rails/rails-html-sanitizer] for more information. # - # 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 - # <tt>:attributes</tt> or <tt>:tags</tt> options: + # Custom sanitization rules can also be provided. # - # Normal Use - # - # <%= sanitize @article.body %> + # Please note that sanitizing user-provided text does not guarantee that the + # resulting markup is valid or even well-formed. For example, the output may still + # contain unescaped characters like <tt><</tt>, <tt>></tt>, or <tt>&</tt>. # - # Custom Use - Custom Scrubber - # (supply a Loofah::Scrubber that does the sanitization) + # ==== Options # - # scrubber can either wrap a block: - # scrubber = Loofah::Scrubber.new do |node| - # node.text = "dawn of cats" - # end + # * <tt>:tags</tt> - An array of allowed tags. + # * <tt>:attributes</tt> - An array of allowed attributes. + # * <tt>:scrubber</tt> - A {Rails::Html scrubber}[https://github.com/rails/rails-html-sanitizer] + # or {Loofah::Scrubber}[https://github.com/flavorjones/loofah] object that + # defines custom sanitization rules. A custom scrubber takes precedence over + # custom tags and attributes. # - # 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 + # ==== Examples # - # <%= sanitize @article.body, scrubber: scrubber %> + # Normal use: # - # A custom scrubber takes precedence over custom tags and attributes - # Learn more about scrubbers here: https://github.com/flavorjones/loofah + # <%= sanitize @comment.body %> # - # Custom Use - tags and attributes - # (only the mentioned tags and attributes are allowed, nothing else) + # Providing custom whitelisted tags and attributes: # - # <%= sanitize @article.body, tags: %w(table tr td), attributes: %w(id class style) %> + # <%= sanitize @comment.body, tags: %w(strong em a), attributes: %w(href) %> # - # Add table tags to the default allowed tags + # Providing a custom Rails::Html scrubber: # - # class Application < Rails::Application - # config.action_view.sanitized_allowed_tags = ['table', 'tr', 'td'] - # end + # class CommentScrubber < Rails::Html::PermitScrubber + # def allowed_node?(node) + # !%w(form script comment blockquote).include?(node.name) + # end # - # Remove tags to the default allowed tags + # def skip_node?(node) + # node.text? + # end # - # class Application < Rails::Application - # config.after_initialize do - # ActionView::Base.sanitized_allowed_tags.delete 'div' + # def scrub_attribute?(name) + # name == 'style' # end # end # - # Change allowed default attributes + # <%= sanitize @comment.body, scrubber: CommentScrubber.new %> + # + # See {Rails HTML Sanitizer}[https://github.com/rails/rails-html-sanitizer] for + # documentation about Rails::Html scrubbers. # - # class Application < Rails::Application - # config.action_view.sanitized_allowed_attributes = ['id', 'class', 'style'] + # Providing a custom Loofah::Scrubber: + # + # scrubber = Loofah::Scrubber.new do |node| + # node.remove if node.name == 'script' # 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. + # <%= sanitize @comment.body, scrubber: scrubber %> + # + # See {Loofah's documentation}[https://github.com/flavorjones/loofah] for more + # information about defining custom Loofah::Scrubber objects. # + # To set the default allowed tags or attributes across your application: + # + # # In config/application.rb + # config.action_view.sanitized_allowed_tags = ['strong', 'em', 'a'] + # config.action_view.sanitized_allowed_attributes = ['href', 'title'] def sanitize(html, options = {}) self.class.white_list_sanitizer.sanitize(html, options).try(:html_safe) end @@ -87,9 +88,7 @@ module ActionView 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. + # Strips all HTML tags from +html+, including comments. # # strip_tags("Strip <i>these</i> tags!") # # => Strip these tags! @@ -103,7 +102,7 @@ module ActionView self.class.full_sanitizer.sanitize(html) end - # Strips all link tags from +text+ leaving just the link text. + # Strips all link tags from +html+ leaving just the link text. # # strip_links('<a href="http://www.rubyonrails.org">Ruby on Rails</a>') # # => Ruby on Rails @@ -166,30 +165,6 @@ module ActionView def white_list_sanitizer @white_list_sanitizer ||= sanitizer_vendor.white_list_sanitizer.new end - - ## - # :method: sanitized_allowed_tags= - # - # :call-seq: sanitized_allowed_tags=(tags) - # - # Replaces the allowed tags for the +sanitize+ helper. - # - # class Application < Rails::Application - # config.action_view.sanitized_allowed_tags = ['table', 'tr', 'td'] - # end - # - - ## - # :method: sanitized_allowed_attributes= - # - # :call-seq: sanitized_allowed_attributes=(attributes) - # - # Replaces the allowed HTML attributes for the +sanitize+ helper. - # - # class Application < Rails::Application - # config.action_view.sanitized_allowed_attributes = ['onclick', 'longdesc'] - # end - # end end end |