discourse/app/assets/javascripts/pretty-text/sanitizer.js.es6

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import xss from 'pretty-text/xss';
const _validIframes = [];
function attr(name, value) {
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if (value) {
return `${name}="${xss.escapeAttrValue(value)}"`;
}
return name;
}
const ESCAPE_REPLACEMENTS = {
"&": "&",
"<": "&lt;",
">": "&gt;",
'"': "&quot;",
"'": "&#x27;",
'`': '&#x60;'
};
const BAD_CHARS = /[&<>"'`]/g;
const POSSIBLE_CHARS = /[&<>"'`]/;
function escapeChar(chr) {
return ESCAPE_REPLACEMENTS[chr];
}
export function escape(string) {
// don't escape SafeStrings, since they're already safe
if (string === null) {
return "";
} else if (!string) {
return string + '';
}
// Force a string conversion as this will be done by the append regardless and
// the regex test will do this transparently behind the scenes, causing issues if
// an object's to string has escaped characters in it.
string = "" + string;
if (!POSSIBLE_CHARS.test(string)) { return string; }
return string.replace(BAD_CHARS, escapeChar);
}
export function hrefAllowed(href, extraHrefMatchers) {
// escape single quotes
href = href.replace(/'/g, "%27");
// absolute urls
if (/^(https?:)?\/\/[\w\.\-]+/i.test(href)) { return href; }
// relative urls
if (/^\/[\w\.\-]+/i.test(href)) { return href; }
// anchors
if (/^#[\w\.\-]+/i.test(href)) { return href; }
// mailtos
if (/^mailto:[\w\.\-@]+/i.test(href)) { return href; }
if (extraHrefMatchers && extraHrefMatchers.length > 0) {
for (let i=0; i<extraHrefMatchers.length; i++) {
if (extraHrefMatchers[i].test(href)) { return href; }
}
}
}
export function sanitize(text, whiteLister) {
if (!text) return "";
// Allow things like <3 and <_<
text = text.replace(/<([^A-Za-z\/\!]|$)/g, "&lt;$1");
const whiteList = whiteLister.getWhiteList(),
allowedHrefSchemes = whiteLister.getAllowedHrefSchemes();
let extraHrefMatchers = null;
if (allowedHrefSchemes && allowedHrefSchemes.length > 0) {
extraHrefMatchers = [new RegExp('^(' + allowedHrefSchemes.join('|') + '):\/\/[\\w\\.\\-]+','i')];
}
let result = xss(text, {
whiteList: whiteList.tagList,
stripIgnoreTag: true,
stripIgnoreTagBody: ['script', 'table'],
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onIgnoreTagAttr(tag, name, value) {
const forTag = whiteList.attrList[tag];
if (forTag) {
const forAttr = forTag[name];
if ((forAttr && (forAttr.indexOf('*') !== -1 || forAttr.indexOf(value) !== -1)) ||
(name.indexOf('data-') === 0 && forTag['data-*']) ||
((tag === 'a' && name === 'href') && hrefAllowed(value, extraHrefMatchers)) ||
(tag === 'img' && name === 'src' && (/^data:image.*$/i.test(value) || hrefAllowed(value, extraHrefMatchers))) ||
(tag === 'iframe' && name === 'src' && _validIframes.some(i => i.test(value)))) {
return attr(name, value);
}
if (tag === 'iframe' && name === 'src') {
return "-STRIP-";
}
const custom = whiteLister.getCustom();
for (let i=0; i<custom.length; i++) {
const fn = custom[i];
if (fn(tag, name, value)) {
return attr(name, value);
}
}
}
},
});
return result.replace(/\[removed\]/g, '')
.replace(/\<iframe[^>]+\-STRIP\-[^>]*>[^<]*<\/iframe>/g, '')
.replace(/&(?![#\w]+;)/g, '&amp;')
.replace(/&#39;/g, "'")
.replace(/ \/>/g, '>');
};
export function whiteListIframe(regexp) {
_validIframes.push(regexp);
}
whiteListIframe(/^(https?:)?\/\/www\.google\.com\/maps\/embed\?.+/i);
whiteListIframe(/^(https?:)?\/\/www\.openstreetmap\.org\/export\/embed.html\?.+/i);