Add XSS filter

lib/channel-new.js

@@ -8,6 +8,7 @@ var AsyncQueue = require("./asyncqueue");
 var MakeEmitter = require("./emitter");
 var InfoGetter = require("./get-info");
 var ChatCommand = require("./chatcommand");
+var XSS = require("./xss");
 
 var fs = require("fs");
 var path = require("path");
@@ -572,16 +573,6 @@ Channel.prototype.part = function (user) {
     }
 };
 
-/**
- * Set the MOTD and broadcast it to connected users
- */
-Channel.prototype.setMOTD = function (message) {
-    this.motd.motd = message;
-    // TODO XSS filter
-    this.motd.html = message.replace(/\n/g, "<br>");
-    this.sendMOTD(this.users);
-};
-
 /**
  * Send the MOTD to the given users
  */
@@ -2194,9 +2185,9 @@ Channel.prototype.validateChatFilter = function (f) {
     }
 
     f.replace = f.replace.substring(0, 1000);
+    f.replace = XSS.sanitizeHTML(f.replace);
     f.flags = f.flags.substring(0, 4);
 
-    // TODO XSS prevention
     try {
         new RegExp(f.source, f.flags);
     } catch (e) {
@@ -2493,7 +2484,7 @@ Channel.prototype.handleSetJS = function (user, data) {
  * Sets the MOTD
  */
 Channel.prototype.setMotd = function (motd) {
-    // TODO XSS
+    motd = XSS.sanitizeHTML(motd);
     var html = motd.replace(/\n/g, "<br>");
     this.motd = {
         motd: motd,
@@ -2557,7 +2548,7 @@ Channel.prototype.handleChat = function (user, data) {
     }
 
     if (smuted) {
-        // TODO XSS
+        msg = XSS.sanitizeText(msg);
         msg = this.filterMessage(msg);
         var msgobj = {
             username: user.name,
@@ -2629,7 +2620,7 @@ Channel.prototype.filterMessage = function (msg) {
  * Sends a chat message
  */
 Channel.prototype.sendMessage = function (user, msg, meta) {
-    // TODO HTML escape
+    msg = XSS.sanitizeText(msg);
     msg = this.filterMessage(msg);
     var msgobj = {
         username: user.name,
@@ -2645,7 +2636,7 @@ Channel.prototype.sendMessage = function (user, msg, meta) {
     }
 
     this.logger.log("<" + user.name + (meta.addClass ? "." + meta.addClass : "") + "> " +
-                    msg);
+                    XSS.decodeText(msg));
 };
 
 /**

lib/poll.js

@@ -1,11 +1,11 @@
 /*
 The MIT License (MIT)
 Copyright (c) 2013 Calvin Montgomery
- 
+
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
- 
+
 The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
- 
+
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 const link = /(\w+:\/\/(?:[^:\/\[\]\s]+|\[[0-9a-f:]+\])(?::\d+)?(?:\/[^\/\s]*)*)/ig;

lib/xss.js

@@ -46,6 +46,16 @@ TagParser.prototype.readLiteral = function (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;
 };
 
@@ -53,7 +63,7 @@ TagParser.prototype.readLiteral = function (regexp) {
    a string.  Otherwise, read a literal
 */
 TagParser.prototype.readLiteralOrString = function (regexp) {
-    if (this.text[this.i].match(/["']/)) {
+    if (this.text[this.i].match(/["'`]/)) {
         return this.readString();
     }
     return this.readLiteral(regexp);
@@ -78,6 +88,16 @@ TagParser.prototype.readString = function () {
         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;
 };
 
@@ -120,7 +140,7 @@ TagParser.prototype.parse = function () {
         }
 
         this.i++;
-        this.skipWhitespace();
+        //this.skipWhitespace();
         var value = this.readLiteralOrString();
         if (key.trim().length > 0) {
             attrs[key] = value;
@@ -181,7 +201,8 @@ const badTags = new RegExp([
 */
 const badAttrs = new RegExp([
     "\\bon\\S*",
-    "\\bformaction"
+    "\\bformaction",
+    "\\baction"
 ].join("|"), "i");
 
 /* These are things commonly used in the values of HTML attributes of
@@ -226,7 +247,7 @@ function sanitizeHTML(str) {
             // If it's an evil attribute, just nuke it entirely
             if (k.match(badAttrs)) {
                 delete t.attributes[k];
-            } else  {
+            } else {
                 if (t.attributes[k].match(badAttrValues)) {
                     // As above, replacing with a nonempty string is important.
                     t.attributes[k] = t.attributes[k].replace(badAttrValues, "[removed]");
@@ -240,7 +261,14 @@ function sanitizeHTML(str) {
             if (k.trim().length > 0) {
                 fmt += " " + k;
                 if (t.attributes[k].trim().length > 0) {
-                    fmt += '="' + t.attributes[k] + '"';
+                    var delim = '"';
+                    if (t.attributes[k].match(/[^\\]"/)) {
+                        delim = "'";
+                        if (t.attributes[k].match(/[^\\]'/)) {
+                            delim = "`";
+                        }
+                    }
+                    fmt += "=" + delim + t.attributes[k] + delim;
                 }
             }
         }
@@ -264,10 +292,10 @@ function sanitizeText(str) {
 }
 
 function decodeText(str) {
-    str = str.replace(/&#([0-9]{2,4});?/g, function (m, p1) {
+    str = str.replace(/&#([0-9]{2,7});?/g, function (m, p1) {
         return String.fromCharCode(parseInt(p1));
     });
-    str = str.replace(/&#x([0-9a-f]{2,4});?/ig, function (m, p1) {
+    str = str.replace(/&#x([0-9a-f]{2,7});?/ig, function (m, p1) {
         return String.fromCharCode(parseInt(p1, 16));
     });
     str = str.replace(/&lt;/g, "<")