gitlab-org--gitlab-foss/lib/gitlab/sanitizers/svg.rb

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# frozen_string_literal: true
module Gitlab
module Sanitizers
module SVG
def self.clean(data)
Loofah.xml_document(data).scrub!(Scrubber.new).to_s
end
class Scrubber < Loofah::Scrubber
# http://www.whatwg.org/specs/web-apps/current-work/multipage/elements.html#embedding-custom-non-visible-data-with-the-data-*-attributes
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DATA_ATTR_PATTERN = /\Adata-(?!xml)[a-z_][\w.\u00E0-\u00F6\u00F8-\u017F\u01DD-\u02AF-]*\z/u.freeze
def scrub(node)
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unless Whitelist::ALLOWED_ELEMENTS.include?(node.name)
node.unlink
return
end
valid_attributes = Whitelist::ALLOWED_ATTRIBUTES[node.name]
return unless valid_attributes
node.attribute_nodes.each do |attr|
attr_name = attribute_name_with_namespace(attr)
if valid_attributes.include?(attr_name)
attr.unlink if unsafe_href?(attr)
else
# Arbitrary data attributes are allowed.
unless allows_data_attribute?(node) && data_attribute?(attr)
attr.unlink
end
end
end
end
def attribute_name_with_namespace(attr)
if attr.namespace
"#{attr.namespace.prefix}:#{attr.name}"
else
attr.name
end
end
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def allows_data_attribute?(node)
Whitelist::ALLOWED_DATA_ATTRIBUTES_IN_ELEMENTS.include?(node.name)
end
def unsafe_href?(attr)
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attribute_name_with_namespace(attr) == 'xlink:href' && !attr.value.start_with?('#')
end
def data_attribute?(attr)
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attr.name.start_with?('data-') && attr.name =~ DATA_ATTR_PATTERN && attr.namespace.nil?
end
end
end
end
end