diff --git a/lib/banzai/filter/autolink_filter.rb b/lib/banzai/filter/autolink_filter.rb index 799b83b1069..80c844baecd 100644 --- a/lib/banzai/filter/autolink_filter.rb +++ b/lib/banzai/filter/autolink_filter.rb @@ -71,6 +71,14 @@ module Banzai @doc = parse_html(rinku) end + # 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 + # Autolinks any text matching LINK_PATTERN that Rinku didn't already # replace def text_parse @@ -89,17 +97,27 @@ module Banzai doc end - def autolink_filter(text) - text.gsub(LINK_PATTERN) do |match| - # Remove any trailing HTML entities and store them for appending - # outside the link element. The entity must be marked HTML safe in - # order to be output literally rather than escaped. - match.gsub!(/((?:&[\w#]+;)+)\z/, '') - dropped = ($1 || '').html_safe - - options = link_options.merge(href: match) - content_tag(:a, match, options) + dropped + def autolink_match(match) + # start by stripping out dangerous links + begin + uri = Addressable::URI.parse(match) + return match if contains_unsafe?(uri.scheme) + rescue Addressable::URI::InvalidURIError + return match end + + # Remove any trailing HTML entities and store them for appending + # outside the link element. The entity must be marked HTML safe in + # order to be output literally rather than escaped. + match.gsub!(/((?:&[\w#]+;)+)\z/, '') + dropped = ($1 || '').html_safe + + options = link_options.merge(href: match) + content_tag(:a, match, options) + dropped + end + + def autolink_filter(text) + text.gsub(LINK_PATTERN) { |match| autolink_match(match) } end def link_options diff --git a/spec/lib/banzai/filter/autolink_filter_spec.rb b/spec/lib/banzai/filter/autolink_filter_spec.rb index dca7f997570..a6d2ea11fcc 100644 --- a/spec/lib/banzai/filter/autolink_filter_spec.rb +++ b/spec/lib/banzai/filter/autolink_filter_spec.rb @@ -99,6 +99,28 @@ describe Banzai::Filter::AutolinkFilter, lib: true do expect(doc.at_css('a')['href']).to eq link end + it 'autolinks rdar' do + link = 'rdar://localhost.com/blah' + doc = filter("See #{link}") + + expect(doc.at_css('a').text).to eq link + expect(doc.at_css('a')['href']).to eq link + end + + it 'does not autolink javascript' do + link = 'javascript://alert(document.cookie);' + doc = filter("See #{link}") + + expect(doc.at_css('a')).to be_nil + end + + it 'does not autolink bad URLs' do + link = 'foo://23423:::asdf' + doc = filter("See #{link}") + + expect(doc.to_s).to eq("See #{link}") + end + it 'does not include trailing punctuation' do doc = filter("See #{link}.") expect(doc.at_css('a').text).to eq link