svgedit/packages/svgcanvas/sanitize.js

253 lines
14 KiB
JavaScript

/**
* Tools for SVG sanitization.
* @module sanitize
* @license MIT
*
* @copyright 2010 Alexis Deveria, 2010 Jeff Schiller
*/
import { getReverseNS, NS } from './namespaces.js'
import { getHref, setHref, getUrlFromAttr } from './utilities.js'
const REVERSE_NS = getReverseNS()
// Todo: Split out into core attributes, presentation attributes, etc. so consistent
/**
* This defines which elements and attributes that we support (or at least
* don't remove).
* @type {PlainObject}
*/
/* eslint-disable max-len */
const svgGenericWhiteList = ['class', 'id', 'display', 'transform', 'style']
const svgWhiteList_ = {
// SVG Elements
a: ['clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'mask', 'opacity', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage', 'xlink:href', 'xlink:title'],
circle: ['clip-path', 'clip-rule', 'cx', 'cy', 'enable-background', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'mask', 'opacity', 'r', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage'],
clipPath: ['clipPathUnits'],
defs: [],
desc: [],
ellipse: ['clip-path', 'clip-rule', 'cx', 'cy', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'mask', 'opacity', 'requiredFeatures', 'rx', 'ry', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage'],
feBlend: ['in', 'in2'],
feColorMatrix: ['in', 'type', 'value', 'result', 'values'],
feComposite: ['in', 'operator', 'result', 'in2'],
feFlood: ['flood-color', 'in', 'result', 'flood-opacity'],
feGaussianBlur: ['color-interpolation-filters', 'in', 'requiredFeatures', 'stdDeviation', 'result'],
feMerge: [],
feMergeNode: ['in'],
feMorphology: ['in', 'operator', 'radius'],
feOffset: ['dx', 'in', 'dy', 'result'],
filter: ['color-interpolation-filters', 'filterRes', 'filterUnits', 'height', 'primitiveUnits', 'requiredFeatures', 'width', 'x', 'xlink:href', 'y'],
foreignObject: ['font-size', 'height', 'opacity', 'requiredFeatures', 'width', 'x', 'y'],
g: ['clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage', 'font-family', 'font-size', 'font-style', 'font-weight', 'text-anchor'],
image: ['clip-path', 'clip-rule', 'filter', 'height', 'mask', 'opacity', 'requiredFeatures', 'systemLanguage', 'width', 'x', 'xlink:href', 'xlink:title', 'y'],
line: ['clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage', 'x1', 'x2', 'y1', 'y2'],
linearGradient: ['gradientTransform', 'gradientUnits', 'requiredFeatures', 'spreadMethod', 'systemLanguage', 'x1', 'x2', 'xlink:href', 'y1', 'y2'],
marker: ['markerHeight', 'markerUnits', 'markerWidth', 'orient', 'preserveAspectRatio', 'refX', 'refY', 'se_type', 'systemLanguage', 'viewBox'],
mask: ['height', 'maskContentUnits', 'maskUnits', 'width', 'x', 'y'],
metadata: [],
path: ['clip-path', 'clip-rule', 'd', 'enable-background', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage'],
pattern: ['height', 'patternContentUnits', 'patternTransform', 'patternUnits', 'requiredFeatures', 'systemLanguage', 'viewBox', 'width', 'x', 'xlink:href', 'y'],
polygon: ['clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'points', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage', 'sides', 'shape', 'edge', 'point', 'starRadiusMultiplier', 'r', 'radialshift', 'r2', 'orient', 'cx', 'cy'],
polyline: ['clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'points', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage', 'se:connector'],
radialGradient: ['cx', 'cy', 'fx', 'fy', 'gradientTransform', 'gradientUnits', 'r', 'requiredFeatures', 'spreadMethod', 'systemLanguage', 'xlink:href'],
rect: ['clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'height', 'mask', 'opacity', 'requiredFeatures', 'rx', 'ry', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage', 'width', 'x', 'y'],
stop: ['offset', 'requiredFeatures', 'stop-opacity', 'systemLanguage', 'stop-color', 'gradientUnits', 'gradientTransform'],
style: ['type'],
svg: ['clip-path', 'clip-rule', 'enable-background', 'filter', 'height', 'mask', 'preserveAspectRatio', 'requiredFeatures', 'systemLanguage', 'version', 'viewBox', 'width', 'x', 'xmlns', 'xmlns:se', 'xmlns:xlink', 'xmlns:oi', 'oi:animations', 'y', 'stroke-linejoin', 'fill-rule', 'aria-label', 'stroke-width', 'fill-rule', 'xml:space'],
switch: ['requiredFeatures', 'systemLanguage'],
symbol: ['fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight', 'opacity', 'overflow', 'preserveAspectRatio', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage', 'viewBox', 'width', 'height'],
text: ['clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage', 'text-anchor', 'letter-spacing', 'word-spacing', 'text-decoration', 'textLength', 'lengthAdjust', 'x', 'xml:space', 'y'],
textPath: ['method', 'requiredFeatures', 'spacing', 'startOffset', 'systemLanguage', 'xlink:href'],
title: [],
tspan: ['clip-path', 'clip-rule', 'dx', 'dy', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight', 'mask', 'opacity', 'requiredFeatures', 'rotate', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'systemLanguage', 'text-anchor', 'textLength', 'x', 'xml:space', 'y'],
use: ['clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'height', 'mask', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'width', 'x', 'xlink:href', 'y', 'overflow'],
// MathML Elements
annotation: ['encoding'],
'annotation-xml': ['encoding'],
maction: ['actiontype', 'other', 'selection'],
math: ['xmlns'],
menclose: ['notation'],
merror: [],
mfrac: ['linethickness'],
mi: ['mathvariant'],
mmultiscripts: [],
mn: [],
mo: ['fence', 'lspace', 'maxsize', 'minsize', 'rspace', 'stretchy'],
mover: [],
mpadded: ['lspace', 'width', 'height', 'depth', 'voffset'],
mphantom: [],
mprescripts: [],
mroot: [],
mrow: ['xlink:href', 'xlink:type', 'xmlns:xlink'],
mspace: ['depth', 'height', 'width'],
msqrt: [],
mstyle: ['displaystyle', 'mathbackground', 'mathcolor', 'mathvariant', 'scriptlevel'],
msub: [],
msubsup: [],
msup: [],
mtable: ['align', 'columnalign', 'columnlines', 'columnspacing', 'displaystyle', 'equalcolumns', 'equalrows', 'frame', 'rowalign', 'rowlines', 'rowspacing', 'width'],
mtd: ['columnalign', 'columnspan', 'rowalign', 'rowspan'],
mtext: [],
mtr: ['columnalign', 'rowalign'],
munder: [],
munderover: [],
none: [],
semantics: []
}
/* eslint-enable max-len */
// add generic attributes to all elements of the whitelist
Object.keys(svgWhiteList_).forEach((element) => { svgWhiteList_[element] = [...svgWhiteList_[element], ...svgGenericWhiteList] })
// Produce a Namespace-aware version of svgWhitelist
const svgWhiteListNS_ = {}
Object.entries(svgWhiteList_).forEach(([elt, atts]) => {
const attNS = {}
Object.entries(atts).forEach(([_i, att]) => {
if (att.includes(':')) {
const v = att.split(':')
attNS[v[1]] = NS[(v[0]).toUpperCase()]
} else {
attNS[att] = att === 'xmlns' ? NS.XMLNS : null
}
})
svgWhiteListNS_[elt] = attNS
})
/**
* Sanitizes the input node and its children.
* It only keeps what is allowed from our whitelist defined above.
* @function module:sanitize.sanitizeSvg
* @param {Text|Element} node - The DOM element to be checked (we'll also check its children) or text node to be cleaned up
* @returns {void}
*/
export const sanitizeSvg = (node) => {
// Cleanup text nodes
if (node.nodeType === 3) { // 3 === TEXT_NODE
// Trim whitespace
node.nodeValue = node.nodeValue.trim()
// Remove if empty
if (!node.nodeValue.length) {
node.remove()
}
}
// We only care about element nodes.
// Automatically return for all non-element nodes, such as comments, etc.
if (node.nodeType !== 1) { // 1 == ELEMENT_NODE
return
}
const doc = node.ownerDocument
const parent = node.parentNode
// can parent ever be null here? I think the root node's parent is the document...
if (!doc || !parent) {
return
}
const allowedAttrs = svgWhiteList_[node.nodeName]
const allowedAttrsNS = svgWhiteListNS_[node.nodeName]
// if this element is supported, sanitize it
if (typeof allowedAttrs !== 'undefined') {
const seAttrs = []
let i = node.attributes.length
while (i--) {
// if the attribute is not in our whitelist, then remove it
const attr = node.attributes.item(i)
const attrName = attr.nodeName
const attrLocalName = attr.localName
const attrNsURI = attr.namespaceURI
// Check that an attribute with the correct localName in the correct namespace is on
// our whitelist or is a namespace declaration for one of our allowed namespaces
if (attrNsURI !== allowedAttrsNS[attrLocalName] && attrNsURI !== NS.XMLNS &&
!(attrNsURI === NS.XMLNS && REVERSE_NS[attr.value])) {
// Bypassing the whitelist to allow se: and oi: prefixes
// We can add specific namepaces on demand for now.
// Is there a more appropriate way to do this?
if (attrName.startsWith('se:') || attrName.startsWith('oi:') || attrName.startsWith('data-')) {
// We should bypass the namespace aswell
const seAttrNS = (attrName.startsWith('se:')) ? NS.SE : ((attrName.startsWith('oi:')) ? NS.OI : null)
seAttrs.push([attrName, attr.value, seAttrNS])
} else {
console.warn(`sanitizeSvg: attribute ${attrName} in element ${node.nodeName} not in whitelist is removed`)
node.removeAttributeNS(attrNsURI, attrLocalName)
}
}
// For the style attribute, rewrite it in terms of XML presentational attributes
if (attrName === 'style') {
const props = attr.value.split(';')
let p = props.length
while (p--) {
const [name, val] = props[p].split(':')
const styleAttrName = (name || '').trim()
const styleAttrVal = (val || '').trim()
// Now check that this attribute is supported
if (allowedAttrs.includes(styleAttrName)) {
node.setAttribute(styleAttrName, styleAttrVal)
}
}
node.removeAttribute('style')
}
}
Object.values(seAttrs).forEach(([att, val, ns]) => {
node.setAttributeNS(ns, att, val)
})
// for some elements that have a xlink:href, ensure the URI refers to a local element
// (but not for links)
const href = getHref(node)
if (href &&
['filter', 'linearGradient', 'pattern',
'radialGradient', 'textPath', 'use'].includes(node.nodeName) && href[0] !== '#') {
// remove the attribute (but keep the element)
setHref(node, '')
console.warn(`sanitizeSvg: attribute href in element ${node.nodeName} pointing to a non-local reference (${href}) is removed`)
node.removeAttributeNS(NS.XLINK, 'href')
}
// Safari crashes on a <use> without a xlink:href, so we just remove the node here
if (node.nodeName === 'use' && !getHref(node)) {
console.warn(`sanitizeSvg: element ${node.nodeName} without a xlink:href is removed`)
node.remove()
return
}
// if the element has attributes pointing to a non-local reference,
// need to remove the attribute
Object.values(['clip-path', 'fill', 'filter', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'stroke'], (attr) => {
let val = node.getAttribute(attr)
if (val) {
val = getUrlFromAttr(val)
// simply check for first character being a '#'
if (val && val[0] !== '#') {
node.setAttribute(attr, '')
console.warn(`sanitizeSvg: attribute ${attr} in element ${node.nodeName} pointing to a non-local reference (${val}) is removed`)
node.removeAttribute(attr)
}
}
})
// recurse to children
i = node.childNodes.length
while (i--) { sanitizeSvg(node.childNodes.item(i)) }
// else (element not supported), remove it
} else {
// remove all children from this node and insert them before this node
// TODO: in the case of animation elements this will hardly ever be correct
console.warn(`sanitizeSvg: element ${node.nodeName} not supported is removed`)
const children = []
while (node.hasChildNodes()) {
children.push(parent.insertBefore(node.firstChild, node))
}
// remove this node from the document altogether
node.remove()
// call sanitizeSvg on each of those children
let i = children.length
while (i--) { sanitizeSvg(children[i]) }
}
}