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|
# frozen_string_literal: true
class Sanitize
module Config
HTTP_PROTOCOLS = %w(
http
https
).freeze
LINK_PROTOCOLS = %w(
http
https
dat
dweb
ipfs
ipns
ssb
gopher
xmpp
magnet
gemini
).freeze
CLASS_WHITELIST_TRANSFORMER = lambda do |env|
node = env[:node]
class_list = node['class']&.split(/[\t\n\f\r ]/)
return unless class_list
class_list.keep_if do |e|
next true if /^(h|p|u|dt|e)-/.match?(e) # microformats classes
next true if /^(mention|hashtag)$/.match?(e) # semantic classes
next true if /^(ellipsis|invisible)$/.match?(e) # link formatting classes
end
node['class'] = class_list.join(' ')
end
IMG_TAG_TRANSFORMER = lambda do |env|
node = env[:node]
return unless env[:node_name] == 'img'
node.name = 'a'
node['href'] = node['src']
if node['alt'].present?
node.content = "[🖼 #{node['alt']}]"
else
url = node['href']
prefix = url.match(/\Ahttps?:\/\/(www\.)?/).to_s
text = url[prefix.length, 30]
text = text + "…" if url[prefix.length..-1].length > 30
node.content = "[🖼 #{text}]"
end
end
UNSUPPORTED_HREF_TRANSFORMER = lambda do |env|
return unless env[:node_name] == 'a'
current_node = env[:node]
scheme = begin
if current_node['href'] =~ Sanitize::REGEX_PROTOCOL
Regexp.last_match(1).downcase
else
:relative
end
end
current_node.replace(Nokogiri::XML::Text.new(current_node.text, current_node.document)) unless LINK_PROTOCOLS.include?(scheme)
end
MASTODON_STRICT ||= freeze_config(
elements: %w(p br span a abbr del pre blockquote code b strong u sub sup i em h1 h2 h3 h4 h5 ul ol li),
attributes: {
'a' => %w(href rel class title),
'span' => %w(class),
'abbr' => %w(title),
'blockquote' => %w(cite),
'ol' => %w(start reversed),
'li' => %w(value),
},
add_attributes: {
'a' => {
'rel' => 'nofollow noopener noreferrer',
'target' => '_blank',
},
},
protocols: {
'a' => { 'href' => LINK_PROTOCOLS },
'blockquote' => { 'cite' => LINK_PROTOCOLS },
},
transformers: [
CLASS_WHITELIST_TRANSFORMER,
IMG_TAG_TRANSFORMER,
UNSUPPORTED_HREF_TRANSFORMER,
]
)
MASTODON_OEMBED ||= freeze_config merge(
RELAXED,
elements: RELAXED[:elements] + %w(audio embed iframe source video),
attributes: merge(
RELAXED[:attributes],
'audio' => %w(controls),
'embed' => %w(height src type width),
'iframe' => %w(allowfullscreen frameborder height scrolling src width),
'source' => %w(src type),
'video' => %w(controls height loop width),
'div' => [:data]
),
protocols: merge(
RELAXED[:protocols],
'embed' => { 'src' => HTTP_PROTOCOLS },
'iframe' => { 'src' => HTTP_PROTOCOLS },
'source' => { 'src' => HTTP_PROTOCOLS }
)
)
LINK_REL_TRANSFORMER = lambda do |env|
return unless env[:node_name] == 'a' && env[:node]['href']
node = env[:node]
rel = (node['rel'] || '').split(' ') & ['tag']
rel += ['nofollow', 'noopener', 'noreferrer'] unless TagManager.instance.local_url?(node['href'])
if rel.empty?
node.remove_attribute('rel')
else
node['rel'] = rel.join(' ')
end
end
LINK_TARGET_TRANSFORMER = lambda do |env|
return unless env[:node_name] == 'a' && env[:node]['href']
node = env[:node]
if node['target'] != '_blank' && TagManager.instance.local_url?(node['href'])
node.remove_attribute('target')
else
node['target'] = '_blank'
end
end
MASTODON_OUTGOING ||= freeze_config MASTODON_STRICT.merge(
attributes: merge(
MASTODON_STRICT[:attributes],
'a' => %w(href rel class title target)
),
add_attributes: {},
transformers: [
CLASS_WHITELIST_TRANSFORMER,
IMG_TAG_TRANSFORMER,
UNSUPPORTED_HREF_TRANSFORMER,
LINK_REL_TRANSFORMER,
LINK_TARGET_TRANSFORMER,
]
)
end
end
|
