html5lib-python/src/html5lib/sanitizer.py at python3-old · feitianyiren/html5lib-python · GitHub

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import re

from xml.sax.saxutils import escape, unescape

from tokenizer import HTMLTokenizer

from constants import tokenTypes

class HTMLSanitizerMixin(object):

""" sanitization of XHTML+MathML+SVG and of inline style attributes."""

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',

'linearGradient', 'line', 'marker', 'metadata', 'missing-glyph',

'mpath', 'path', 'polygon', 'polyline', 'radialGradient', 'rect',

'set', 'stop', 'svg', 'switch', 'text', 'title', 'tspan', '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', 'poster', 'preload', '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', 'dx',

'dy', 'descent', 'display', 'dur', 'end', 'fill', 'fill-opacity',

'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', 'marker-end', 'marker-mid',

'marker-start', 'markerHeight', 'markerUnits', 'markerWidth',

'mathematical', 'max', 'min', 'name', 'offset', 'opacity', 'orient',

'origin', 'overline-position', 'overline-thickness', 'panose-1',

'path', 'pathLength', 'points', 'preserveAspectRatio', 'r', 'refX',

'refY', '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-opacity',

'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']

attr_val_is_uri = ['href', 'src', 'cite', 'action', 'longdesc',

'xlink:href', 'xml:base']

svg_attr_val_allows_ref = ['clip-path', 'color-profile', 'cursor', 'fill',

'filter', 'marker', 'marker-start', 'marker-mid', 'marker-end', 'mask', 'stroke']

svg_allow_local_href = ['altGlyph', 'animate', 'animateColor', 'animateMotion',

'animateTransform', 'cursor', 'feImage', 'filter', 'linearGradient', 'pattern',

'radialGradient', 'textpath', 'tref', 'set', 'use']

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']

acceptable_protocols = [ 'ed2k', 'ftp', 'http', 'https', 'irc',

'mailto', 'news', 'gopher', 'nntp', 'telnet', 'webcal',

'xmpp', 'callto', 'feed', 'urn', 'aim', 'rsync', 'tag',

'ssh', 'sftp', 'rtsp', 'afs' ]

# subclasses may define their own versions of these constants

allowed_elements = acceptable_elements + mathml_elements + svg_elements

allowed_attributes = acceptable_attributes + mathml_attributes + svg_attributes

allowed_css_properties = acceptable_css_properties

allowed_css_keywords = acceptable_css_keywords

allowed_svg_properties = acceptable_svg_properties

allowed_protocols = acceptable_protocols

# 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.

# attributes in ATTR_VAL_IS_URI are scanned, and only URI schemes specified

# in ALLOWED_PROTOCOLS are allowed.

# sanitize_html('<script> do_nasty_stuff() </script>')

# => <script> do_nasty_stuff() </script>

# sanitize_html('<a href="javascript: sucker();">Click here for $100</a>')

# => <a>Click here for $100</a>

def sanitize_token(self, token):

if token["type"] in (tokenTypes["StartTag"], tokenTypes["EndTag"],

tokenTypes["EmptyTag"]):

if token["name"] in self.allowed_elements:

if token.has_key("data"):

attrs = dict([(name,val) for name,val in

token["data"][::-1]

if name in self.allowed_attributes])

for attr in self.attr_val_is_uri:

if not attrs.has_key(attr):

continue

val_unescaped = re.sub("[`\000-\040\177-\240\s]+", '',

unescape(attrs[attr])).lower()

if (re.match("^[a-z0-9][-+.a-z0-9]*:",val_unescaped) and

(val_unescaped.split(':')[0] not in

self.allowed_protocols)):

del attrs[attr]

for attr in self.svg_attr_val_allows_ref:

if attr in attrs:

attrs[attr] = re.sub(r'url\s*$\s*[^#\s][^)]+?$',

' ',

unescape(attrs[attr]))

if (token["name"] in self.svg_allow_local_href and

'xlink:href' in attrs and re.find('^\s*[^#\s].*',

attrs['xlink:href'])):

del attrs['xlink:href']

if attrs.has_key('style'):

attrs['style'] = self.sanitize_css(attrs['style'])

token["data"] = [[name,val] for name,val in attrs.items()]

return token

else:

if token["type"] == tokenTypes["EndTag"]:

token["data"] = "</%s>" % token["name"]

elif token["data"]:

attrs = ''.join([' %s="%s"' % (k,escape(v)) for k,v in token["data"]])

token["data"] = "<%s%s>" % (token["name"],attrs)

else:

token["data"] = "<%s>" % token["name"]

if token["type"] == tokenTypes["EmptyTag"]:

token["data"]=token["data"][:-1] + "/>"

token["type"] = tokenTypes["Characters"]

del token["name"]

return token

elif token["type"] == tokenTypes["Comment"]:

pass

else:

return token

def sanitize_css(self, style):

# disallow urls

style=re.compile('url\s*$\s*[^\s)]+?\s*$\s*').sub(' ',style)

# gauntlet

if not re.match("""^([:,;#%.\sa-zA-Z0-9!]|\w-\w|'[\s\w]+'|"[\s\w]+"|$[\d,\s]+$)*$""", style): return ''

if not re.match("^\s*([-\w]+\s*:[^:;]*(;\s*|$))*$", style): return ''

clean = []

for prop,value in re.findall("([-\w]+)\s*:\s*([^:;]*)",style):

if not value: continue

if prop.lower() in self.allowed_css_properties:

clean.append(prop + ': ' + value + ';')

elif prop.split('-')[0].lower() in ['background','border','margin',

'padding']:

for keyword in value.split():

if not keyword in self.acceptable_css_keywords and \

not re.match("^(#[0-9a-f]+|rgb$\d+%?,\d*%?,?\d*%?$?|\d{0,2}\.?\d{0,2}(cm|em|ex|in|mm|pc|pt|px|%|,|\))?)$",keyword):

break

else:

clean.append(prop + ': ' + value + ';')

elif prop.lower() in self.allowed_svg_properties:

clean.append(prop + ': ' + value + ';')

return ' '.join(clean)

class HTMLSanitizer(HTMLTokenizer, HTMLSanitizerMixin):

def __init__(self, stream, encoding=None, parseMeta=True, useChardet=True,

lowercaseElementName=False, lowercaseAttrName=False):

#Change case matching defaults as we only output lowercase html anyway

#This solution doesn't seem ideal...

HTMLTokenizer.__init__(self, stream, encoding, parseMeta, useChardet,

lowercaseElementName, lowercaseAttrName)

def __iter__(self):

for token in HTMLTokenizer.__iter__(self):

token = self.sanitize_token(token)

if token:

yield token

html5lib-python/src/html5lib/sanitizer.py at python3-old · feitianyiren/html5lib-python · GitHub

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