HackMD/public/js/render.js
Sheogorath c59b94a37b
Remove the xss library from webpack
We can load the xss functions directly from the library instead of
loading them through the expose loader of webpack, this should simplify
the setup and maybe even improve speed a bit.

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>
2018-11-10 20:27:07 +01:00

78 lines
2.6 KiB
JavaScript

/* eslint-env browser, jquery */
// allow some attributes
var filterXSS = require('xss')
var whiteListAttr = ['id', 'class', 'style']
window.whiteListAttr = whiteListAttr
// allow link starts with '.', '/' and custom protocol with '://', exclude link starts with javascript://
var linkRegex = /^(?!javascript:\/\/)([\w|-]+:\/\/)|^([.|/])+/i
// allow data uri, from https://gist.github.com/bgrins/6194623
var dataUriRegex = /^\s*data:([a-z]+\/[a-z0-9-+.]+(;[a-z-]+=[a-z0-9-]+)?)?(;base64)?,([a-z0-9!$&',()*+;=\-._~:@/?%\s]*)\s*$/i
// custom white list
var whiteList = filterXSS.whiteList
// allow ol specify start number
whiteList['ol'] = ['start']
// allow li specify value number
whiteList['li'] = ['value']
// allow style tag
whiteList['style'] = []
// allow kbd tag
whiteList['kbd'] = []
// allow ifram tag with some safe attributes
whiteList['iframe'] = ['allowfullscreen', 'name', 'referrerpolicy', 'sandbox', 'src', 'width', 'height']
// allow summary tag
whiteList['summary'] = []
// allow ruby tag
whiteList['ruby'] = []
// allow rp tag for ruby
whiteList['rp'] = []
// allow rt tag for ruby
whiteList['rt'] = []
// allow figure tag
whiteList['figure'] = []
// allow figcaption tag
whiteList['figcaption'] = []
var filterXSSOptions = {
allowCommentTag: true,
whiteList: whiteList,
escapeHtml: function (html) {
// allow html comment in multiple lines
return html.replace(/<(?!!--)/g, '&lt;').replace(/-->/g, '__HTML_COMMENT_END__').replace(/>/g, '&gt;').replace(/__HTML_COMMENT_END__/g, '-->')
},
onIgnoreTag: function (tag, html, options) {
// allow comment tag
if (tag === '!--') {
// do not filter its attributes
return html
}
},
onTagAttr: function (tag, name, value, isWhiteAttr) {
// allow href and src that match linkRegex
if (isWhiteAttr && (name === 'href' || name === 'src') && linkRegex.test(value)) {
return name + '="' + filterXSS.escapeAttrValue(value) + '"'
}
// allow data uri in img src
if (isWhiteAttr && (tag === 'img' && name === 'src') && dataUriRegex.test(value)) {
return name + '="' + filterXSS.escapeAttrValue(value) + '"'
}
},
onIgnoreTagAttr: function (tag, name, value, isWhiteAttr) {
// allow attr start with 'data-' or in the whiteListAttr
if (name.substr(0, 5) === 'data-' || window.whiteListAttr.indexOf(name) !== -1) {
// escape its value using built-in escapeAttrValue function
return name + '="' + filterXSS.escapeAttrValue(value) + '"'
}
}
}
function preventXSS (html) {
return filterXSS(html, filterXSSOptions)
}
window.preventXSS = preventXSS
module.exports = {
preventXSS: preventXSS,
escapeAttrValue: filterXSS.escapeAttrValue
}