/**
* 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', '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' ],
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', '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(function ([ _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 = function (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-')) {
seAttrs.push([ attrName, attr.value ]);
} 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 ]) => {
node.setAttributeNS(NS.SE, 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' ], function (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]); }
}
};