class Rails::HTML::PermitScrubber
with nodes: nokogiri.org/rdoc/Nokogiri/XML/Node.html<br>See the documentation for Nokogiri::XML::Node
to understand what’s possible
end
end
name == “style”
def scrub_attribute?(name)
end
node.text?
def skip_node?(node)
end
self.tags = %w(form script comment blockquote)
super
def initialize
class CommentScrubber < Rails::HTML::PermitScrubber
If not, attributes are removed based on Loofahs HTML5::Scrub.scrub_attributes
.
If set, attributes excluded will be removed.attributes=
If not, elements are stripped based on Loofahs HTML5::Scrub.allowed_element?
.
If set, elements excluded will be stripped.tags=
Supplied tags and attributes should be Enumerables.
Unallowed elements will be stripped, i.e. element is removed but its subtree kept.
Text and CDATA nodes are skipped by default.
Likewise for scrub_attribute?
and attributes respectively.
Instead Loofahs behavior will be used.
If you override allowed_node?
and no tags are set, it will not be called.
If tags or attributes are not set, Loofah’s behavior will be used.
Subclasses don’t need to worry if tags or attributes are set or not.
- When an attribute should be scrubbed via scrub_attribute?
.
- When a node is allowed via allowed_node?
.
- When a node should be skipped via skip_node?
.Rails::HTML::PermitScrubber
can be subclassed to determine:Rails::HTML::PermitScrubber
allows you to permit only your own tags and/or attributes.
=== Rails::HTML::PermitScrubber
def allowed_node?(node)
def allowed_node?(node) @tags.include?(node.name) end
def attributes=(attributes)
def attributes=(attributes) @attributes = validate!(attributes, :attributes) end
def initialize(prune: false)
def initialize(prune: false) @prune = prune @direction = @prune ? :top_down : :bottom_up @tags, @attributes = nil, nil end
def keep_node?(node)
def keep_node?(node) if @tags allowed_node?(node) else Loofah::HTML5::Scrub.allowed_element?(node.name) end end
def scrub(node)
def scrub(node) if Loofah::HTML5::Scrub.cdata_needs_escaping?(node) replacement = Loofah::HTML5::Scrub.cdata_escape(node) node.replace(replacement) return CONTINUE end return CONTINUE if skip_node?(node) unless (node.element? || node.comment?) && keep_node?(node) return STOP unless scrub_node(node) == CONTINUE end scrub_attributes(node) CONTINUE end
def scrub_attribute(node, attr_node)
def scrub_attribute(node, attr_node) attr_name = if attr_node.namespace "#{attr_node.namespace.prefix}:#{attr_node.node_name}" else attr_node.node_name end return if Loofah::HTML5::SafeList::ATTR_VAL_IS_URI.include?(attr_name) && Loofah::HTML5::Scrub.scrub_uri_attribute(attr_node) if Loofah::HTML5::SafeList::SVG_ATTR_VAL_ALLOWS_REF.include?(attr_name) Loofah::HTML5::Scrub.scrub_attribute_that_allows_local_ref(attr_node) end if Loofah::HTML5::SafeList::SVG_ALLOW_LOCAL_HREF.include?(node.name) && attr_name == "xlink:href" && attr_node.value =~ /^\s*[^#\s].*/m attr_node.remove end node.remove_attribute(attr_node.name) if attr_name == "src" && attr_node.value !~ /[^[:space:]]/ Loofah::HTML5::Scrub.force_correct_attribute_escaping! node end
def scrub_attribute?(name)
def scrub_attribute?(name) !@attributes.include?(name) end
def scrub_attributes(node)
def scrub_attributes(node) if @attributes node.attribute_nodes.each do |attr| if scrub_attribute?(attr.name) attr.remove else scrub_attribute(node, attr) end end scrub_css_attribute(node) else Loofah::HTML5::Scrub.scrub_attributes(node) end end
def scrub_css_attribute(node)
def scrub_css_attribute(node) if Loofah::HTML5::Scrub.respond_to?(:scrub_css_attribute) Loofah::HTML5::Scrub.scrub_css_attribute(node) else style = node.attributes["style"] style.value = Loofah::HTML5::Scrub.scrub_css(style.value) if style end end
def scrub_node(node)
def scrub_node(node) # If a node has a namespace, then it's a tag in either a `math` or `svg` foreign context, # and we should always prune it to avoid namespace confusion and mutation XSS vectors. unless prune || node.namespace node.before(node.children) end node.remove end
def skip_node?(node)
def skip_node?(node) node.text? end
def tags=(tags)
def tags=(tags) @tags = validate!(tags, :tags) end
def validate!(var, name)
def validate!(var, name) if var && !var.is_a?(Enumerable) raise ArgumentError, "You should pass :#{name} as an Enumerable" end if var && name == :tags if var.include?("mglyph") warn("WARNING: 'mglyph' tags cannot be allowed by the PermitScrubber and will be scrubbed") var.delete("mglyph") end if var.include?("malignmark") warn("WARNING: 'malignmark' tags cannot be allowed by the PermitScrubber and will be scrubbed") var.delete("malignmark") end if var.include?("noscript") warn("WARNING: 'noscript' tags cannot be allowed by the PermitScrubber and will be scrubbed") var.delete("noscript") end end var end