diff options
Diffstat (limited to 'actionview/lib/action_view/helpers/sanitize_helper.rb')
| -rw-r--r-- | actionview/lib/action_view/helpers/sanitize_helper.rb | 223 |
1 files changed, 69 insertions, 154 deletions
diff --git a/actionview/lib/action_view/helpers/sanitize_helper.rb b/actionview/lib/action_view/helpers/sanitize_helper.rb index 049af275b6..463a4e9f60 100644 --- a/actionview/lib/action_view/helpers/sanitize_helper.rb +++ b/actionview/lib/action_view/helpers/sanitize_helper.rb @@ -1,5 +1,5 @@ require 'active_support/core_ext/object/try' -require 'action_view/vendor/html-scanner' +require 'rails-html-sanitizer' module ActionView # = Action View Sanitize Helpers @@ -8,54 +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 + # 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>. # - # <%= sanitize @article.body %> + # ==== Options # - # Custom Use (only the mentioned tags and attributes are allowed, nothing else) + # * <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. # - # <%= sanitize @article.body, tags: %w(table tr td), attributes: %w(id class style) %> + # ==== Examples # - # Add table tags to the default allowed tags + # Normal use: # - # class Application < Rails::Application - # config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td' - # end + # <%= sanitize @comment.body %> + # + # Providing custom whitelisted tags and attributes: + # + # <%= sanitize @comment.body, tags: %w(strong em a), attributes: %w(href) %> + # + # Providing a custom Rails::Html scrubber: # - # Remove tags to the default allowed tags + # class CommentScrubber < Rails::Html::PermitScrubber + # def allowed_node?(node) + # !%w(form script comment blockquote).include?(node.name) + # end + # + # 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. + # + # Providing a custom Loofah::Scrubber: # - # class Application < Rails::Application - # config.action_view.sanitized_allowed_attributes = ['id', 'class', 'style'] + # 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 @@ -65,9 +88,7 @@ module ActionView self.class.white_list_sanitizer.sanitize_css(style) end - # Strips all HTML tags from the +html+, including comments. This uses the - # html-scanner tokenizer and so its HTML parsing ability is limited by - # that of html-scanner. + # Strips all HTML tags from +html+, including comments. # # strip_tags("Strip <i>these</i> tags!") # # => Strip these tags! @@ -81,7 +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 @@ -98,47 +119,21 @@ module ActionView 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 + # Vendors the full, link and white list sanitizers. + # Provided strictly for compabitility and can be removed in Rails 5. + def sanitizer_vendor + Rails::Html::Sanitizer end def sanitized_allowed_tags - white_list_sanitizer.allowed_tags + sanitizer_vendor.white_list_sanitizer.allowed_tags end def sanitized_allowed_attributes - white_list_sanitizer.allowed_attributes + sanitizer_vendor.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 - - def sanitized_protocol_separator=(value) - white_list_sanitizer.protocol_separator = value - end - - # Gets the HTML::FullSanitizer instance used by +strip_tags+. Replace with + # Gets the Rails::Html::FullSanitizer instance used by +strip_tags+. Replace with # any object that responds to +sanitize+. # # class Application < Rails::Application @@ -146,21 +141,21 @@ module ActionView # end # def full_sanitizer - @full_sanitizer ||= HTML::FullSanitizer.new + @full_sanitizer ||= sanitizer_vendor.full_sanitizer.new end - # Gets the HTML::LinkSanitizer instance used by +strip_links+. Replace with - # any object that responds to +sanitize+. + # Gets the Rails::Html::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 ||= HTML::LinkSanitizer.new + @link_sanitizer ||= sanitizer_vendor.link_sanitizer.new end - # Gets the HTML::WhiteListSanitizer instance used by sanitize and +sanitize_css+. + # Gets the Rails::Html::WhiteListSanitizer instance used by sanitize and +sanitize_css+. # Replace with any object that responds to +sanitize+. # # class Application < Rails::Application @@ -168,87 +163,7 @@ module ActionView # end # def white_list_sanitizer - @white_list_sanitizer ||= HTML::WhiteListSanitizer.new - 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) - HTML::WhiteListSanitizer.uri_attributes.merge(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) - HTML::WhiteListSanitizer.bad_tags.merge(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) - HTML::WhiteListSanitizer.allowed_tags.merge(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) - HTML::WhiteListSanitizer.allowed_attributes.merge(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) - HTML::WhiteListSanitizer.allowed_css_properties.merge(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) - HTML::WhiteListSanitizer.allowed_css_keywords.merge(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) - HTML::WhiteListSanitizer.shorthand_css_properties.merge(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) - HTML::WhiteListSanitizer.allowed_protocols.merge(attributes) + @white_list_sanitizer ||= sanitizer_vendor.white_list_sanitizer.new end end end |