Stackedit/public/res/extensions/htmlSanitizer.js

402 lines
11 KiB
JavaScript

define([
"jquery",
"underscore",
"utils",
"logger",
"classes/Extension",
"text!html/htmlSanitizerSettingsBlock.html"
], function($, _, utils, logger, Extension, htmlSanitizerSettingsBlockHTML) {
var htmlSanitizer = new Extension("htmlSanitizer", "HTML Sanitizer", true);
htmlSanitizer.settingsBlock = htmlSanitizerSettingsBlockHTML;
var buf;
htmlSanitizer.onPagedownConfigure = function(editor) {
var converter = editor.getConverter();
converter.hooks.chain("postConversion", function(html) {
buf = [];
html.split('<div class="se-preview-section-delimiter"></div>').forEach(function(sectionHtml) {
htmlParser(sectionHtml, htmlSanitizeWriter(buf, function(uri, isImage) {
return !/^unsafe/.test(sanitizeUri(uri, isImage));
}));
buf.push('<div class="se-preview-section-delimiter"></div>');
});
return buf.slice(0, -1).join('');
});
};
/**
* @license AngularJS v1.2.16
* (c) 2010-2014 Google, Inc. http://angularjs.org
* License: MIT
*/
var aHrefSanitizationWhitelist = /^\s*(https?|ftp|mailto|tel|file):/,
imgSrcSanitizationWhitelist = /^\s*(https?|ftp|file):|data:image\//;
function sanitizeUri(uri, isImage) {
var regex = isImage ? imgSrcSanitizationWhitelist : aHrefSanitizationWhitelist;
var normalizedVal;
normalizedVal = utils.urlResolve(uri).href;
if(normalizedVal !== '' && !normalizedVal.match(regex)) {
return 'unsafe:' + normalizedVal;
}
}
// Regular Expressions for parsing tags and attributes
var START_TAG_REGEXP =
/^<\s*([\w:-]+)((?:\s+[\w:-]+(?:\s*=\s*(?:(?:"[^"]*")|(?:'[^']*')|[^>\s]+))?)*)\s*(\/?)\s*>/,
END_TAG_REGEXP = /^<\s*\/\s*([\w:-]+)[^>]*>/,
ATTR_REGEXP = /([\w:-]+)(?:\s*=\s*(?:(?:"((?:[^"])*)")|(?:'((?:[^'])*)')|([^>\s]+)))?/g,
BEGIN_TAG_REGEXP = /^</,
BEGING_END_TAGE_REGEXP = /^<\s*\//,
COMMENT_REGEXP = /<!--(.*?)-->/g,
DOCTYPE_REGEXP = /<!DOCTYPE([^>]*?)>/i,
CDATA_REGEXP = /<!\[CDATA\[(.*?)]]>/g,
// Match everything outside of normal chars and " (quote character)
NON_ALPHANUMERIC_REGEXP = /([^\#-~| |!])/g;
function makeMap(str) {
var obj = {}, items = str.split(','), i;
for(i = 0; i < items.length; i++) {
obj[items[i]] = true;
}
return obj;
}
// Good source of info about elements and attributes
// http://dev.w3.org/html5/spec/Overview.html#semantics
// http://simon.html5.org/html-elements
// Safe Void Elements - HTML5
// http://dev.w3.org/html5/spec/Overview.html#void-elements
var voidElements = makeMap("area,br,col,hr,img,wbr");
// Elements that you can, intentionally, leave open (and which close themselves)
// http://dev.w3.org/html5/spec/Overview.html#optional-tags
var optionalEndTagBlockElements = makeMap("colgroup,dd,dt,li,p,tbody,td,tfoot,th,thead,tr"),
optionalEndTagInlineElements = makeMap("rp,rt"),
optionalEndTagElements = _.extend({},
optionalEndTagInlineElements,
optionalEndTagBlockElements);
// Safe Block Elements - HTML5
var blockElements = _.extend({}, optionalEndTagBlockElements, makeMap("address,article," +
"aside,blockquote,caption,center,del,dir,div,dl,figure,figcaption,footer,h1,h2,h3,h4,h5," +
"h6,header,hgroup,hr,ins,map,menu,nav,ol,pre,script,section,table,ul"));
// Inline Elements - HTML5
var inlineElements = _.extend({}, optionalEndTagInlineElements, makeMap("a,abbr,acronym,b," +
"bdi,bdo,big,br,cite,code,del,dfn,em,font,i,img,ins,kbd,label,map,mark,q,ruby,rp,rt,s," +
"samp,small,span,strike,strong,sub,sup,time,tt,u,var"));
// Special Elements (can contain anything)
var specialElements = makeMap("script,style");
// benweet: Add iframe
blockElements.iframe = true;
var validElements = _.extend({},
voidElements,
blockElements,
inlineElements,
optionalEndTagElements);
//Attributes that have href and hence need to be sanitized
var uriAttrs = makeMap("background,cite,href,longdesc,src,usemap");
var validAttrs = _.extend({}, uriAttrs, makeMap(
'abbr,align,alt,axis,bgcolor,border,cellpadding,cellspacing,class,clear,' +
'color,cols,colspan,compact,coords,dir,face,headers,height,hreflang,hspace,' +
'ismap,lang,language,nohref,nowrap,rel,rev,rows,rowspan,rules,' +
'scope,scrolling,shape,size,span,start,summary,target,title,type,' +
'valign,value,vspace,width'));
// benweet: Add id and allowfullscreen (YouTube iframe)
validAttrs.id = true;
validAttrs.allowfullscreen = true;
/*
* HTML Parser By Misko Hevery (misko@hevery.com)
* based on: HTML Parser By John Resig (ejohn.org)
* Original code by Erik Arvidsson, Mozilla Public License
* http://erik.eae.net/simplehtmlparser/simplehtmlparser.js
*
* // Use like so:
* htmlParser(htmlString, {
* start: function(tag, attrs, unary) {},
* end: function(tag) {},
* chars: function(text) {},
* comment: function(text) {}
* });
*
*/
/* jshint -W083 */
function htmlParser(html, handler) {
var index, chars, match, stack = [], last = html;
stack.last = function() {
return stack[ stack.length - 1 ];
};
function parseStartTag(tag, tagName, rest, unary) {
tagName = tagName && tagName.toLowerCase();
if(blockElements[ tagName ]) {
while(stack.last() && inlineElements[ stack.last() ]) {
parseEndTag("", stack.last());
}
}
if(optionalEndTagElements[ tagName ] && stack.last() == tagName) {
parseEndTag("", tagName);
}
unary = voidElements[ tagName ] || !!unary;
if(!unary) {
stack.push(tagName);
}
var attrs = {};
rest.replace(ATTR_REGEXP,
function(match, name, doubleQuotedValue, singleQuotedValue, unquotedValue) {
var value = doubleQuotedValue ||
singleQuotedValue ||
unquotedValue ||
'';
attrs[name] = decodeEntities(value);
});
if(handler.start) {
handler.start(tagName, attrs, unary);
}
}
function parseEndTag(tag, tagName) {
var pos = 0, i;
tagName = tagName && tagName.toLowerCase();
if(tagName) {
// Find the closest opened tag of the same type
for(pos = stack.length - 1; pos >= 0; pos--) {
if(stack[ pos ] == tagName) {
break;
}
}
}
if(pos >= 0) {
// Close all the open elements, up the stack
for(i = stack.length - 1; i >= pos; i--) {
if(handler.end) {
handler.end(stack[ i ]);
}
}
// Remove the open elements from the stack
stack.length = pos;
}
}
while(html) {
chars = true;
// Make sure we're not in a script or style element
if(!stack.last() || !specialElements[ stack.last() ]) {
// Comment
if(html.indexOf("<!--") === 0) {
// comments containing -- are not allowed unless they terminate the comment
index = html.indexOf("--", 4);
if(index >= 0 && html.lastIndexOf("-->", index) === index) {
if(handler.comment) {
handler.comment(html.substring(4, index));
}
html = html.substring(index + 3);
chars = false;
}
// DOCTYPE
} else if(DOCTYPE_REGEXP.test(html)) {
match = html.match(DOCTYPE_REGEXP);
if(match) {
html = html.replace(match[0], '');
chars = false;
}
// end tag
} else if(BEGING_END_TAGE_REGEXP.test(html)) {
match = html.match(END_TAG_REGEXP);
if(match) {
html = html.substring(match[0].length);
match[0].replace(END_TAG_REGEXP, parseEndTag);
chars = false;
}
// start tag
} else if(BEGIN_TAG_REGEXP.test(html)) {
match = html.match(START_TAG_REGEXP);
if(match) {
html = html.substring(match[0].length);
match[0].replace(START_TAG_REGEXP, parseStartTag);
chars = false;
}
}
if(chars) {
index = html.indexOf("<");
var text = index < 0 ? html : html.substring(0, index);
html = index < 0 ? "" : html.substring(index);
if(handler.chars) {
handler.chars(decodeEntities(text));
}
}
} else {
html = html.replace(new RegExp("(.*)<\\s*\\/\\s*" + stack.last() + "[^>]*>", 'i'),
function(all, text) {
text = text.replace(COMMENT_REGEXP, "$1").replace(CDATA_REGEXP, "$1");
if(handler.chars) {
handler.chars(decodeEntities(text));
}
return "";
});
parseEndTag("", stack.last());
}
if(html == last) {
//throw new Error("The sanitizer was unable to parse the following block of html: " + html);
stack.reverse();
return stack.forEach(function(tag) {
buf.push('</');
buf.push(tag);
buf.push('>');
});
}
last = html;
}
// Clean up any remaining tags
parseEndTag();
}
var hiddenPre = document.createElement("pre");
var spaceRe = /^(\s*)([\s\S]*?)(\s*)$/;
/**
* decodes all entities into regular string
* @param value
* @returns {string} A string with decoded entities.
*/
function decodeEntities(value) {
if(!value) {
return '';
}
// Note: IE8 does not preserve spaces at the start/end of innerHTML
// so we must capture them and reattach them afterward
var parts = spaceRe.exec(value);
var spaceBefore = parts[1];
var spaceAfter = parts[3];
var content = parts[2];
if(content) {
hiddenPre.innerHTML = content.replace(/</g, "&lt;");
// innerText depends on styling as it doesn't display hidden elements.
// Therefore, it's better to use textContent not to cause unnecessary
// reflows. However, IE<9 don't support textContent so the innerText
// fallback is necessary.
content = 'textContent' in hiddenPre ?
hiddenPre.textContent : hiddenPre.innerText;
}
return spaceBefore + content + spaceAfter;
}
/**
* Escapes all potentially dangerous characters, so that the
* resulting string can be safely inserted into attribute or
* element text.
* @param value
* @returns {string} escaped text
*/
function encodeEntities(value) {
return value.
replace(/&/g, '&amp;').
replace(NON_ALPHANUMERIC_REGEXP, function(value) {
return '&#' + value.charCodeAt(0) + ';';
}).
replace(/</g, '&lt;').
replace(/>/g, '&gt;');
}
/**
* create an HTML/XML writer which writes to buffer
* @param {Array} buf use buf.jain('') to get out sanitized html string
* @returns {object} in the form of {
* start: function(tag, attrs, unary) {},
* end: function(tag) {},
* chars: function(text) {},
* comment: function(text) {}
* }
*/
function htmlSanitizeWriter(buf, uriValidator) {
var ignore = false;
var out = _.bind(buf.push, buf);
return {
start: function(tag, attrs, unary) {
tag = tag && tag.toLowerCase();
if(!ignore && specialElements[tag]) {
ignore = tag;
}
if(!ignore && validElements[tag] === true) {
out('<');
out(tag);
_.forEach(attrs, function(value, key) {
var lkey = key && key.toLowerCase();
var isImage = (tag === 'img' && lkey === 'src') || (lkey === 'background');
if(validAttrs[lkey] === true &&
(uriAttrs[lkey] !== true || uriValidator(value, isImage))) {
out(' ');
out(key);
out('="');
out(encodeEntities(value));
out('"');
}
});
out(unary ? '/>' : '>');
}
},
end: function(tag) {
tag = tag && tag.toLowerCase();
if(!ignore && validElements[tag] === true) {
out('</');
out(tag);
out('>');
}
if(tag == ignore) {
ignore = false;
}
},
chars: function(chars) {
if(!ignore) {
out(encodeEntities(chars));
}
},
comment: function(comment) {
if(!ignore) {
out('<!--');
out(encodeEntities(comment));
out('-->');
}
}
};
}
return htmlSanitizer;
});