diff --git a/lib/chunks/engines.rb b/lib/chunks/engines.rb
index 526dcb9d..e3d4bc4b 100644
--- a/lib/chunks/engines.rb
+++ b/lib/chunks/engines.rb
@@ -23,75 +23,62 @@ module Engines
end
- MY_VERBOTEN_TAGS = %w(form script plaintext object embed applet iframe frameset frame link meta body style html)
- MY_VERBOTEN_ATTRS = /^on/i
-
class Textile < AbstractEngine
- require_dependency 'action_view/helpers/text_helper'
- ActionView::Helpers::TextHelper::VERBOTEN_TAGS = MY_VERBOTEN_TAGS
- ActionView::Helpers::TextHelper::VERBOTEN_ATTRS = MY_VERBOTEN_ATTRS
- include ActionView::Helpers::TextHelper
+ require_dependency 'sanitize'
+ include Sanitize
def mask
require_dependency 'redcloth'
redcloth = RedCloth.new(@content, [:hard_breaks] + @content.options[:engine_opts])
redcloth.filter_html = false
redcloth.no_span_caps = false
html = redcloth.to_html(:textile)
- sanitize(html)
+ sanitize_html(html)
end
end
class Markdown < AbstractEngine
- require_dependency 'action_view/helpers/text_helper'
- ActionView::Helpers::TextHelper::VERBOTEN_TAGS = MY_VERBOTEN_TAGS
- ActionView::Helpers::TextHelper::VERBOTEN_ATTRS = MY_VERBOTEN_ATTRS
- include ActionView::Helpers::TextHelper
+ require_dependency 'sanitize'
+ include Sanitize
def mask
require_dependency 'maruku'
require_dependency 'maruku/ext/math'
html = Maruku.new(@content.delete("\r\x01-\x08\x0B\x0C\x0E-\x1F"), {:math_enabled => false}).to_html
- sanitize(html)
+ sanitize_html(html)
end
end
class MarkdownMML < AbstractEngine
- require_dependency 'action_view/helpers/text_helper'
- ActionView::Helpers::TextHelper::VERBOTEN_TAGS = MY_VERBOTEN_TAGS
- ActionView::Helpers::TextHelper::VERBOTEN_ATTRS = MY_VERBOTEN_ATTRS
- include ActionView::Helpers::TextHelper
+ require_dependency 'sanitize'
+ include Sanitize
def mask
require_dependency 'maruku'
require_dependency 'maruku/ext/math'
html = Maruku.new(@content.delete("\r\x01-\x08\x0B\x0C\x0E-\x1F"),
{:math_enabled => true, :math_numbered => ['\\[','\\begin{equation}']}).to_html
- sanitize(html)
+ sanitize_html(html)
end
end
class Mixed < AbstractEngine
- require_dependency 'action_view/helpers/text_helper'
- ActionView::Helpers::TextHelper::VERBOTEN_TAGS = MY_VERBOTEN_TAGS
- ActionView::Helpers::TextHelper::VERBOTEN_ATTRS = MY_VERBOTEN_ATTRS
- include ActionView::Helpers::TextHelper
+ require_dependency 'sanitize'
+ include Sanitize
def mask
require_dependency 'redcloth'
redcloth = RedCloth.new(@content, @content.options[:engine_opts])
redcloth.filter_html = false
redcloth.no_span_caps = false
html = redcloth.to_html
- sanitize(html)
+ sanitize_html(html)
end
end
class RDoc < AbstractEngine
- require_dependency 'action_view/helpers/text_helper'
- ActionView::Helpers::TextHelper::VERBOTEN_TAGS = MY_VERBOTEN_TAGS
- ActionView::Helpers::TextHelper::VERBOTEN_ATTRS = MY_VERBOTEN_ATTRS
- include ActionView::Helpers::TextHelper
+ require_dependency 'sanitize'
+ include Sanitize
def mask
require_dependency 'rdocsupport'
html = RDocSupport::RDocFormatter.new(@content).to_html
- sanitize(html)
+ sanitize_html(html)
end
end
diff --git a/lib/sanitize.rb b/lib/sanitize.rb
new file mode 100644
index 00000000..551831ff
--- /dev/null
+++ b/lib/sanitize.rb
@@ -0,0 +1,188 @@
+module Sanitize
+
+# This module provides sanitization of XHTML+MathML+SVG
+# and of inline style attributes.
+#
+# Based heavily on Sam Ruby's code in the Universal FeedParser.
+
+ acceptable_elements = ['a', 'abbr', 'acronym', 'address', 'area', 'b',
+ 'big', 'blockquote', 'br', 'button', 'caption', 'center', 'cite',
+ 'code', 'col', 'colgroup', 'dd', 'del', 'dfn', 'dir', 'div', 'dl', 'dt',
+ 'em', 'fieldset', 'font', 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6',
+ 'hr', 'i', 'img', 'input', 'ins', 'kbd', 'label', 'legend', 'li', 'map',
+ 'menu', 'ol', 'optgroup', 'option', 'p', 'pre', 'q', 's', 'samp',
+ 'select', 'small', 'span', 'strike', 'strong', 'sub', 'sup', 'table',
+ 'tbody', 'td', 'textarea', 'tfoot', 'th', 'thead', 'tr', 'tt', 'u',
+ 'ul', 'var']
+
+ mathml_elements = ['maction', 'math', 'merror', 'mfrac', 'mi',
+ 'mmultiscripts', 'mn', 'mo', 'mover', 'mpadded', 'mphantom',
+ 'mprescripts', 'mroot', 'mrow', 'mspace', 'msqrt', 'mstyle', 'msub',
+ 'msubsup', 'msup', 'mtable', 'mtd', 'mtext', 'mtr', 'munder',
+ 'munderover', 'none']
+
+ svg_elements = ['a', 'animate', 'animateColor', 'animateMotion',
+ 'animateTransform', 'circle', 'defs', 'desc', 'ellipse', 'font-face',
+ 'font-face-name', 'font-face-src', 'g', 'glyph', 'hkern', 'image',
+ 'linearGradient', 'line', 'metadata', 'missing-glyph', 'mpath', 'path',
+ 'polygon', 'polyline', 'radialGradient', 'rect', 'set', 'stop', 'svg',
+ 'switch', 'text', 'title', 'use']
+
+ acceptable_attributes = ['abbr', 'accept', 'accept-charset', 'accesskey',
+ 'action', 'align', 'alt', 'axis', 'border', 'cellpadding',
+ 'cellspacing', 'char', 'charoff', 'charset', 'checked', 'cite', 'class',
+ 'clear', 'cols', 'colspan', 'color', 'compact', 'coords', 'datetime',
+ 'dir', 'disabled', 'enctype', 'for', 'frame', 'headers', 'height',
+ 'href', 'hreflang', 'hspace', 'id', 'ismap', 'label', 'lang',
+ 'longdesc', 'maxlength', 'media', 'method', 'multiple', 'name',
+ 'nohref', 'noshade', 'nowrap', 'prompt', 'readonly', 'rel', 'rev',
+ 'rows', 'rowspan', 'rules', 'scope', 'selected', 'shape', 'size',
+ 'span', 'src', 'start', 'style', 'summary', 'tabindex', 'target', 'title',
+ 'type', 'usemap', 'valign', 'value', 'vspace', 'width', 'xml:lang']
+
+
+ mathml_attributes = ['actiontype', 'align', 'columnalign', 'columnalign',
+ 'columnalign', 'columnlines', 'columnspacing', 'columnspan', 'depth',
+ 'display', 'displaystyle', 'equalcolumns', 'equalrows', 'fence',
+ 'fontstyle', 'fontweight', 'frame', 'height', 'linethickness', 'lspace',
+ 'mathbackground', 'mathcolor', 'mathvariant', 'mathvariant', 'maxsize',
+ 'minsize', 'other', 'rowalign', 'rowalign', 'rowalign', 'rowlines',
+ 'rowspacing', 'rowspan', 'rspace', 'scriptlevel', 'selection',
+ 'separator', 'stretchy', 'width', 'width', 'xlink:href', 'xlink:show',
+ 'xlink:type', 'xmlns', 'xmlns:xlink']
+
+
+ svg_attributes = ['accent-height', 'accumulate', 'additive', 'alphabetic',
+ 'arabic-form', 'ascent', 'attributeName', 'attributeType',
+ 'baseProfile', 'bbox', 'begin', 'by', 'calcMode', 'cap-height',
+ 'class', 'color', 'color-rendering', 'content', 'cx', 'cy', 'd',
+ 'descent', 'display', 'dur', 'end', 'fill', 'fill-rule', 'font-family',
+ 'font-size', 'font-stretch', 'font-style', 'font-variant',
+ 'font-weight', 'from', 'fx', 'fy', 'g1', 'g2', 'glyph-name',
+ 'gradientUnits', 'hanging', 'height', 'horiz-adv-x', 'horiz-origin-x',
+ 'id', 'ideographic', 'k', 'keyPoints', 'keySplines', 'keyTimes',
+ 'lang', 'mathematical', 'max', 'min', 'name', 'offset', 'opacity',
+ 'origin', 'overline-position', 'overline-thickness', 'panose-1',
+ 'path', 'pathLength', 'points', 'preserveAspectRatio', 'r',
+ 'repeatCount', 'repeatDur', 'requiredExtensions', 'requiredFeatures',
+ 'restart', 'rotate', 'rx', 'ry', 'slope', 'stemh', 'stemv',
+ 'stop-color', 'stop-opacity', 'strikethrough-position',
+ 'strikethrough-thickness', 'stroke', 'stroke-dasharray',
+ 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin',
+ 'stroke-miterlimit', 'stroke-width', 'systemLanguage', 'target',
+ 'text-anchor', 'to', 'transform', 'type', 'u1', 'u2',
+ 'underline-position', 'underline-thickness', 'unicode',
+ 'unicode-range', 'units-per-em', 'values', 'version', 'viewBox',
+ 'visibility', 'width', 'widths', 'x', 'x-height', 'x1', 'x2',
+ 'xlink:actuate', 'xlink:arcrole', 'xlink:href', 'xlink:role',
+ 'xlink:show', 'xlink:title', 'xlink:type', 'xml:base', 'xml:lang',
+ 'xml:space', 'xmlns', 'xmlns:xlink', 'y', 'y1', 'y2', 'zoomAndPan']
+
+ acceptable_css_properties = ['azimuth', 'background-color',
+ 'border-bottom-color', 'border-collapse', 'border-color',
+ 'border-left-color', 'border-right-color', 'border-top-color', 'clear',
+ 'color', 'cursor', 'direction', 'display', 'elevation', 'float', 'font',
+ 'font-family', 'font-size', 'font-style', 'font-variant', 'font-weight',
+ 'height', 'letter-spacing', 'line-height', 'overflow', 'pause',
+ 'pause-after', 'pause-before', 'pitch', 'pitch-range', 'richness',
+ 'speak', 'speak-header', 'speak-numeral', 'speak-punctuation',
+ 'speech-rate', 'stress', 'text-align', 'text-decoration', 'text-indent',
+ 'unicode-bidi', 'vertical-align', 'voice-family', 'volume',
+ 'white-space', 'width']
+
+ acceptable_css_keywords = ['auto', 'aqua', 'black', 'block', 'blue',
+ 'bold', 'both', 'bottom', 'brown', 'center', 'collapse', 'dashed',
+ 'dotted', 'fuchsia', 'gray', 'green', '!important', 'italic', 'left',
+ 'lime', 'maroon', 'medium', 'none', 'navy', 'normal', 'nowrap', 'olive',
+ 'pointer', 'purple', 'red', 'right', 'solid', 'silver', 'teal', 'top',
+ 'transparent', 'underline', 'white', 'yellow']
+
+ acceptable_svg_properties = [ 'fill', 'fill-opacity', 'fill-rule',
+ 'stroke', 'stroke-width', 'stroke-linecap', 'stroke-linejoin',
+ 'stroke-opacity']
+
+ ALLOWED_ELEMENTS = acceptable_elements + mathml_elements + svg_elements unless defined?(ALLOWED_ELEMENTS)
+ ALLOWED_ATTRIBUTES = acceptable_attributes + mathml_attributes + svg_attributes unless defined?(ALLOWED_ATTRIBUTES)
+ ALLOWED_CSS_PROPERTIES = acceptable_css_properties unless defined?(ALLOWED_CSS_PROPERTIES)
+ ALLOWED_CSS_KEYWORDS = acceptable_css_keywords unless defined?(ALLOWED_CSS_KEYWORDS)
+ ALLOWED_SVG_PROPERTIES = acceptable_svg_properties unless defined?(ALLOWED_SVG_PROPERTIES)
+
+ # Sanitize the +html+, escaping all elements not in ALLOWED_ELEMENTS, and stripping out all
+ # attributes not in ALLOWED_ATTRIBUTES. Style attributes are parsed, and a restricted set,
+ # specified by ALLOWED_CSS_PROPERTIES and ALLOWED_CSS_KEYWORDS, are allowed through.
+ # You can adjust what gets sanitized, by defining these constant arrays before this Module is loaded.
+ #
+ # sanitize_html('')
+ # => <script> do_nasty_stuff() </script>
+ # sanitize_html('Click here for $100')
+ # => Click here for $100
+ def sanitize_html(html)
+ if html.index("<")
+ tokenizer = HTML::Tokenizer.new(html)
+ new_text = ""
+
+ while token = tokenizer.next
+ node = HTML::Node.parse(nil, 0, 0, token, false)
+ new_text << case node
+ when HTML::Tag
+ if ALLOWED_ELEMENTS.include?(node.name)
+ if node.closing != :close
+ node.attributes.delete_if { |attr,v| !ALLOWED_ATTRIBUTES.include?(attr) }
+ %w(href src).each do |attr|
+ node.attributes.delete attr if node.attributes[attr] =~ /^\s*javascript:/i
+ end
+ if node.attributes['style']
+ node.attributes['style'] = sanitize_css(node.attributes['style'])
+ end
+ end
+ node.to_s
+ else
+ node.to_s.gsub(/, "<")
+ end
+ else
+ node.to_s.gsub(/, "<")
+ end
+ end
+
+ html = new_text
+ end
+ html
+ end
+
+ def sanitize_css(style)
+ # disallow urls
+ style = style.to_s.gsub(/url\s*\(\s*[^\s)]+?\s*\)\s*/, ' ')
+
+ # gauntlet
+ if style !~ /^([:,;#%.\sa-zA-Z0-9!]|\w-\w|\'[\s\w]+\'|\"[\s\w]+\"|\([\d,\s]+\))*$/
+ style = ''
+ return style
+ end
+ if style !~ /^(\s*[-\w]+\s*:\s*[^:;]*(;|$))*$/
+ style = ''
+ return style
+ end
+
+ clean = []
+ style.scan(/([-\w]+)\s*:\s*([^:;]*)/) do |prop,val|
+ if ALLOWED_CSS_PROPERTIES.include?(prop.downcase)
+ clean << prop + ': ' + val + ';'
+ elsif ['background','border','margin','padding'].include?(prop.split('-')[0].downcase)
+ goodval = true
+ val.split().each do |keyword|
+ if !ALLOWED_CSS_KEYWORDS.include?(keyword) and
+ keyword !~ /^(#[0-9a-f]+|rgb\(\d+%?,\d*%?,?\d*%?\)?|\d{0,2}\.?\d{0,2}(cm|em|ex|in|mm|pc|pt|px|%|,|\))?)$/
+ goodval = false
+ end
+ end
+ if goodval
+ clean << prop + ': ' + val + ';'
+ end
+ elsif ALLOWED_SVG_PROPERTIES.include?(prop.downcase)
+ clean << prop + ': ' + val + ';'
+ end
+ end
+
+ style = clean.join(' ')
+ end
+end