Merge pull request #428 from calzoneman/sanitize-html

Merge sanitize-html into 3.0 #yolo
This commit is contained in:
Calvin Montgomery 2015-01-14 13:23:01 -06:00
commit d7ef0d1893
7 changed files with 75 additions and 276 deletions

View file

@ -163,10 +163,7 @@ Channel.prototype.loadState = function () {
var errorLoad = function (msg) {
if (self.modules.customization) {
self.modules.customization.load({
motd: {
motd: msg,
html: msg
}
motd: msg
});
}

View file

@ -17,10 +17,7 @@ function CustomizationModule(channel) {
ChannelModule.apply(this, arguments);
this.css = "";
this.js = "";
this.motd = {
motd: "",
html: ""
};
this.motd = "";
}
CustomizationModule.prototype = Object.create(ChannelModule.prototype);
@ -35,10 +32,15 @@ CustomizationModule.prototype.load = function (data) {
}
if ("motd" in data) {
this.motd = {
motd: data.motd.motd || "",
html: data.motd.html || ""
};
if (typeof data.motd === "object" && data.motd.motd) {
// Old style MOTD, convert to new
this.motd = XSS.sanitizeHTML(data.motd.motd).replace(
/\n/g, "<br>\n");
} else if (typeof data.motd === "string") {
// The MOTD is filtered before it is saved, however it is also
// re-filtered on load in case the filtering rules change
this.motd = XSS.sanitizeHTML(data.motd);
}
}
};
@ -49,12 +51,7 @@ CustomizationModule.prototype.save = function (data) {
};
CustomizationModule.prototype.setMotd = function (motd) {
motd = XSS.sanitizeHTML(motd);
var html = motd.replace(/\n/g, "<br>");
this.motd = {
motd: motd,
html: html
};
this.motd = XSS.sanitizeHTML(motd);
this.sendMotd(this.channel.users);
};

View file

@ -1,260 +1,63 @@
/*
WARNING
var sanitizeHTML = require("sanitize-html");
This file contains an XSS prevention module I wrote myself. It has not
been verified by any external agency, and due to the nature of XSS I cannot
guarantee that it will filter correctly. Feel free to send me bug reports
and I will do my best to fix them, but use at your own risk.
// These tags are allowed in addition to the defaults
// See https://github.com/punkave/sanitize-html
const ALLOWED_TAGS = [
"button",
"center",
"details",
"font",
"h1",
"h2",
"img",
"marquee", // It pains me to do this, but a lot of people use it...
"section",
"span",
"summary"
];
*/
/* Prototype for a basic XML tag parser */
function TagParser(text) {
this.text = text;
this.i = 0;
this.tag = this.parse();
}
/* Moves the position marker past any whitespace characters */
TagParser.prototype.skipWhitespace = function () {
while (this.i < this.text.length && this.text[this.i].match(/\s/)) {
this.i++;
}
};
/* Reads a literal value matching the given regexp. Defaults
to /[^\s>]/; i.e. any string not containing whitespace or
the end of tag character '>'
*/
TagParser.prototype.readLiteral = function (regexp) {
if (regexp === void 0) {
regexp = /[^\s>]/;
}
var str = "";
while (this.i < this.text.length && this.text[this.i].match(regexp)) {
str += this.text[this.i];
this.i++;
}
str = str.replace(/&#([0-9]{2,7});?/g, function (m, p1) {
return String.fromCharCode(parseInt(p1));
});
str = str.replace(/&#x([0-9a-fA-F]{2,7});?/g, function (m, p1) {
return String.fromCharCode(parseInt(p1, 16));
});
str = str.replace(/[\x00-\x1f]/g, "");
return str;
};
/* If the character at the current position is a quote, read
a string. Otherwise, read a literal
*/
TagParser.prototype.readLiteralOrString = function (regexp) {
if (this.text[this.i].match(/["'`]/)) {
return this.readString();
}
return this.readLiteral(regexp);
};
/* Read a string delimited by the character at the current
position. For XML tags this means strings enclosed in
" or '. Treats \" as a literal '"' symbol and not a
delimiter.
*/
TagParser.prototype.readString = function () {
var delim = this.text[this.i++];
var str = "";
while (this.i < this.text.length && this.text[this.i] !== delim) {
if (this.text[this.i] === "\\" && this.text[this.i+1] === delim) {
str += this.text[this.i+1];
this.i++;
} else {
str += this.text[this.i];
}
this.i++;
}
this.i++;
str = str.replace(/&#([0-9]{2,7});?/g, function (m, p1) {
return String.fromCharCode(parseInt(p1));
});
str = str.replace(/&#x([0-9a-fA-F]{2,7});?/g, function (m, p1) {
return String.fromCharCode(parseInt(p1, 16));
});
str = str.replace(/[\x00-\x1f]/g, "");
return str;
};
/* Attempts to parse a tagname and attributes from an
XML tag.
NOTE: Does not actually parse a DOM node, only parses
the tag between '<' and '>' because that's all I need
to do XSS filtering, I don't care what's between a tag
and its end tag (if it's another tag I handle that
separately)
*/
TagParser.prototype.parse = function () {
this.i = this.text.indexOf("<");
// Not a tag
if (this.i === -1) {
return null;
}
this.i++;
this.skipWhitespace();
// First non-whitespace string after the opening '<' is the tag name
var tname = this.readLiteral();
var attrs = {};
// Continue parsing attributes until the end of string is reached or
// the end of tag is reached
while (this.i < this.text.length && this.text[this.i] !== ">") {
// Read any string not containing equals, possibly delimited by
// " or '
var key = this.readLiteralOrString(/[^\s=>]/);
this.skipWhitespace();
// It's possible for tags to have attributes with no value, where
// the equals sign is not necessary
if (this.text[this.i] !== "=") {
if (key.trim().length > 0) {
attrs[key] = "";
}
continue;
}
this.i++;
//this.skipWhitespace();
var value = this.readLiteralOrString();
if (key.trim().length > 0) {
attrs[key] = value;
}
this.skipWhitespace();
}
// If end-of-string was not reached, consume the ending '>'
if (this.i < this.text.length) {
this.i++;
}
return {
tagName: tname,
attributes: attrs,
text: this.text.substring(0, this.i) // Original text (for replacement)
};
};
/* Some of these may not even be HTML tags, I borrowed them from the
[now deprecated] XSS module of node-validator
*/
const badTags = new RegExp([
"alert",
"applet",
"audio",
"basefont",
"base",
"behavior",
"bgsound",
"blink",
"body",
"embed",
"expression",
"form",
"frameset",
"frame",
"head",
"html",
"ilayer",
"iframe",
"input",
"layer",
"link",
"meta",
"object",
const ALLOWED_ATTRIBUTES = [
"id",
"aria-*",
"border",
"class",
"color",
"data-*",
"height",
"role",
"style",
"script",
"textarea",
"title",
"video",
"xml",
"xss"
].join("|"), "i");
"valign",
"width"
];
/* Nasty attributes. Anything starting with "on" is probably a javascript
callback, and I hope you see why formaction is a bad idea.
*/
const badAttrs = new RegExp([
"\\bon\\S*",
"\\bformaction",
"\\baction"
].join("|"), "i");
function sanitizeHTML(str) {
var i = str.indexOf("<");
if (i === -1) {
// No HTML tags in the string
return str;
}
// Loop across all tag delimiters '<' in string, parse each one,
// and replace the results with sanitized tags
while (i !== -1) {
var t = new TagParser(str.substring(i)).tag;
if (t.tagName.replace("/", "").match(badTags)) {
// Note: Important that I replace the tag with a nonempty value,
// otherwise <scr<script>ipt> would possibly defeat the filter.
str = str.replace(t.text, "[tag removed]");
i = str.indexOf("<", i+1);
continue;
}
for (var k in t.attributes) {
// Keys should not contain non-word characters.
var k2 = k.replace(/[^\w]/g, "");
if (k2 !== k) {
t.attributes[k2] = t.attributes[k];
delete t.attributes[k];
k = k2;
}
// If it's an evil attribute, just nuke it entirely
if (k.match(badAttrs)) {
delete t.attributes[k];
} else {
if (t.attributes[k].replace(/\s/g, "").indexOf("javascript:") !== -1) {
t.attributes[k] = "[removed]";
}
}
}
// Build the sanitized tag
var fmt = "<" + t.tagName;
for (var k in t.attributes) {
if (k.trim().length > 0) {
fmt += " " + k;
if (t.attributes[k].trim().length > 0) {
var delim = '"';
if (t.attributes[k].match(/[^\\]"/)) {
delim = "'";
if (t.attributes[k].match(/[^\\]'/)) {
delim = "`";
}
}
fmt += "=" + delim + t.attributes[k] + delim;
}
}
}
str = str.replace(t.text, fmt + ">");
i = str.indexOf("<", i + fmt.length + 1);
}
return str;
var ATTRIBUTE_MAP = {
a: ["href", "name", "target"],
font: ["size"],
img: ["src"],
marquee: ["behavior", "behaviour", "direction", "scrollamount"],
table: ["cellpadding", "cellspacing"],
th: ["colspan", "rowspan"],
td: ["colspan", "rowspan"]
}
/* WIP: Sanitize a string where HTML is prohibited */
for (var key in ATTRIBUTE_MAP) {
ALLOWED_ATTRIBUTES.forEach(function (attr) {
ATTRIBUTE_MAP[key].push(attr);
});
}
sanitizeHTML.defaults.allowedTags.concat(ALLOWED_TAGS).forEach(function (tag) {
if (!(tag in ATTRIBUTE_MAP)) {
ATTRIBUTE_MAP[tag] = ALLOWED_ATTRIBUTES;
}
});
const SETTINGS = {
allowedTags: sanitizeHTML.defaults.allowedTags.concat(ALLOWED_TAGS),
allowedAttributes: ATTRIBUTE_MAP
};
function sanitizeText(str) {
str = str.replace(/&/g, "&amp;")
.replace(/</g, "&lt;")
@ -280,6 +83,9 @@ function decodeText(str) {
return str;
}
module.exports.sanitizeHTML = sanitizeHTML;
module.exports.sanitizeHTML = function (html) {
return sanitizeHTML(html, SETTINGS);
};
module.exports.sanitizeText = sanitizeText;
module.exports.decodeText = decodeText;

View file

@ -22,6 +22,7 @@
"nodemailer": "^1.2.0",
"oauth": "^0.9.12",
"q": "^1.0.1",
"sanitize-html": "^1.5.0",
"serve-static": "^1.5.3",
"socket.io": "^1.2.1",
"yamljs": "^0.1.5"

View file

@ -175,11 +175,10 @@ Callbacks = {
}
},
setMotd: function(data) {
CHANNEL.motd = data.html;
CHANNEL.motd_text = data.motd;
$("#motd").html(CHANNEL.motd);
$("#cs-motdtext").val(CHANNEL.motd_text);
setMotd: function(motd) {
CHANNEL.motd = motd;
$("#motd").html(motd);
$("#cs-motdtext").val(motd);
if (data.motd != "") {
$("#motdwrap").show();
$("#motd").show();

View file

@ -19,7 +19,6 @@ var CHANNEL = {
css: "",
js: "",
motd: "",
motd_text: "",
name: false,
usercount: 0,
emotes: []

View file

@ -900,7 +900,7 @@ function handleModPermissions() {
})();
$("#cs-csstext").val(CHANNEL.css);
$("#cs-jstext").val(CHANNEL.js);
$("#cs-motdtext").val(CHANNEL.motd_text);
$("#cs-motdtext").val(CHANNEL.motd);
setParentVisible("a[href='#cs-motdeditor']", hasPermission("motdedit"));
setParentVisible("a[href='#cs-permedit']", CLIENT.rank >= 3);
setParentVisible("a[href='#cs-banlist']", hasPermission("ban"));