diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/banzai/filter/autolink_filter.rb | 11 | ||||
| -rw-r--r-- | lib/banzai/filter/base_sanitization_filter.rb | 32 | ||||
| -rw-r--r-- | lib/banzai/filter/wiki_link_filter.rb | 15 | ||||
| -rw-r--r-- | lib/banzai/filter/wiki_link_filter/rewriter.rb | 8 | ||||
| -rw-r--r-- | lib/gitlab/utils/sanitize_node_link.rb | 61 |
5 files changed, 77 insertions, 50 deletions
diff --git a/lib/banzai/filter/autolink_filter.rb b/lib/banzai/filter/autolink_filter.rb index 56214043d87..5f2cbc24c60 100644 --- a/lib/banzai/filter/autolink_filter.rb +++ b/lib/banzai/filter/autolink_filter.rb @@ -18,6 +18,7 @@ module Banzai # class AutolinkFilter < HTML::Pipeline::Filter include ActionView::Helpers::TagHelper + include Gitlab::Utils::SanitizeNodeLink # Pattern to match text that should be autolinked. # @@ -72,19 +73,11 @@ module Banzai private - # Return true if any of the UNSAFE_PROTOCOLS strings are included in the URI scheme - def contains_unsafe?(scheme) - return false unless scheme - - scheme = scheme.strip.downcase - Banzai::Filter::SanitizationFilter::UNSAFE_PROTOCOLS.any? { |protocol| scheme.include?(protocol) } - end - def autolink_match(match) # start by stripping out dangerous links begin uri = Addressable::URI.parse(match) - return match if contains_unsafe?(uri.scheme) + return match unless safe_protocol?(uri.scheme) rescue Addressable::URI::InvalidURIError return match end diff --git a/lib/banzai/filter/base_sanitization_filter.rb b/lib/banzai/filter/base_sanitization_filter.rb index 420e92cb1e8..2dabca3552d 100644 --- a/lib/banzai/filter/base_sanitization_filter.rb +++ b/lib/banzai/filter/base_sanitization_filter.rb @@ -11,6 +11,7 @@ module Banzai # Extends HTML::Pipeline::SanitizationFilter with common rules. class BaseSanitizationFilter < HTML::Pipeline::SanitizationFilter include Gitlab::Utils::StrongMemoize + extend Gitlab::Utils::SanitizeNodeLink UNSAFE_PROTOCOLS = %w(data javascript vbscript).freeze @@ -40,7 +41,7 @@ module Banzai # Allow any protocol in `a` elements # and then remove links with unsafe protocols whitelist[:protocols].delete('a') - whitelist[:transformers].push(self.class.remove_unsafe_links) + whitelist[:transformers].push(self.class.method(:remove_unsafe_links)) # Remove `rel` attribute from `a` elements whitelist[:transformers].push(self.class.remove_rel) @@ -54,35 +55,6 @@ module Banzai end class << self - def remove_unsafe_links - lambda do |env| - node = env[:node] - - return unless node.name == 'a' - return unless node.has_attribute?('href') - - begin - node['href'] = node['href'].strip - uri = Addressable::URI.parse(node['href']) - - return unless uri.scheme - - # Remove all invalid scheme characters before checking against the - # list of unsafe protocols. - # - # See https://tools.ietf.org/html/rfc3986#section-3.1 - scheme = uri.scheme - .strip - .downcase - .gsub(/[^A-Za-z0-9\+\.\-]+/, '') - - node.remove_attribute('href') if UNSAFE_PROTOCOLS.include?(scheme) - rescue Addressable::URI::InvalidURIError - node.remove_attribute('href') - end - end - end - def remove_rel lambda do |env| if env[:node_name] == 'a' diff --git a/lib/banzai/filter/wiki_link_filter.rb b/lib/banzai/filter/wiki_link_filter.rb index 1728a442533..18947679b69 100644 --- a/lib/banzai/filter/wiki_link_filter.rb +++ b/lib/banzai/filter/wiki_link_filter.rb @@ -8,15 +8,19 @@ module Banzai # Context options: # :project_wiki class WikiLinkFilter < HTML::Pipeline::Filter + include Gitlab::Utils::SanitizeNodeLink + def call return doc unless project_wiki? - doc.search('a:not(.gfm)').each { |el| process_link_attr(el.attribute('href')) } - doc.search('video').each { |el| process_link_attr(el.attribute('src')) } + doc.search('a:not(.gfm)').each { |el| process_link(el.attribute('href'), el) } + + doc.search('video').each { |el| process_link(el.attribute('src'), el) } + doc.search('img').each do |el| attr = el.attribute('data-src') || el.attribute('src') - process_link_attr(attr) + process_link(attr, el) end doc @@ -24,6 +28,11 @@ module Banzai protected + def process_link(link_attr, node) + process_link_attr(link_attr) + remove_unsafe_links({ node: node }, remove_invalid_links: false) + end + def project_wiki? !context[:project_wiki].nil? end diff --git a/lib/banzai/filter/wiki_link_filter/rewriter.rb b/lib/banzai/filter/wiki_link_filter/rewriter.rb index 77b5053f38c..f4cc8beeb52 100644 --- a/lib/banzai/filter/wiki_link_filter/rewriter.rb +++ b/lib/banzai/filter/wiki_link_filter/rewriter.rb @@ -4,8 +4,6 @@ module Banzai module Filter class WikiLinkFilter < HTML::Pipeline::Filter class Rewriter - UNSAFE_SLUG_REGEXES = [/\Ajavascript:/i].freeze - def initialize(link_string, wiki:, slug:) @uri = Addressable::URI.parse(link_string) @wiki_base_path = wiki && wiki.wiki_base_path @@ -37,8 +35,6 @@ module Banzai # Of the form `./link`, `../link`, or similar def apply_hierarchical_link_rules! - return if slug_considered_unsafe? - @uri = Addressable::URI.join(@slug, @uri) if @uri.to_s[0] == '.' end @@ -58,10 +54,6 @@ module Banzai def repository_upload? @uri.relative? && @uri.path.starts_with?(Wikis::CreateAttachmentService::ATTACHMENT_PATH) end - - def slug_considered_unsafe? - UNSAFE_SLUG_REGEXES.any? { |r| r.match?(@slug) } - end end end end diff --git a/lib/gitlab/utils/sanitize_node_link.rb b/lib/gitlab/utils/sanitize_node_link.rb new file mode 100644 index 00000000000..620d71a7814 --- /dev/null +++ b/lib/gitlab/utils/sanitize_node_link.rb @@ -0,0 +1,61 @@ +# frozen_string_literal: true + +require_dependency 'gitlab/utils' + +module Gitlab + module Utils + module SanitizeNodeLink + UNSAFE_PROTOCOLS = %w(data javascript vbscript).freeze + ATTRS_TO_SANITIZE = %w(href src data-src).freeze + + def remove_unsafe_links(env, remove_invalid_links: true) + node = env[:node] + + sanitize_node(node: node, remove_invalid_links: remove_invalid_links) + + # HTML entities such as <video></video> have scannable attrs in + # children elements, which also need to be sanitized. + # + node.children.each do |child_node| + sanitize_node(node: child_node, remove_invalid_links: remove_invalid_links) + end + end + + # Remove all invalid scheme characters before checking against the + # list of unsafe protocols. + # + # See https://tools.ietf.org/html/rfc3986#section-3.1 + # + def safe_protocol?(scheme) + return false unless scheme + + scheme = scheme + .strip + .downcase + .gsub(/[^A-Za-z\+\.\-]+/, '') + + UNSAFE_PROTOCOLS.none?(scheme) + end + + private + + def sanitize_node(node:, remove_invalid_links: true) + ATTRS_TO_SANITIZE.each do |attr| + next unless node.has_attribute?(attr) + + begin + node[attr] = node[attr].strip + uri = Addressable::URI.parse(node[attr]) + + next unless uri.scheme + next if safe_protocol?(uri.scheme) + + node.remove_attribute(attr) + rescue Addressable::URI::InvalidURIError + node.remove_attribute(attr) if remove_invalid_links + end + end + end + end + end +end |