[fix] Check whether 'Origin' header has invalid characters (#531)

Since the 'Origin' header is used as response header, a value with invalid characters would trigger
'The header content contains invalid characters' errors.

Closes #517

lib/server.js

@@ -150,6 +150,13 @@ Server.prototype.verify = function (req, upgrade, fn) {
     return fn(Server.errors.UNKNOWN_TRANSPORT, false);
   }
 
+  // 'Origin' header check
+  var isOriginInvalid = checkInvalidHeaderChar(req.headers.origin);
+  if (isOriginInvalid) {
+    req.headers.origin = null;
+    return fn(Server.errors.BAD_REQUEST, false);
+  }
+
   // sid check
   var sid = req._query.sid;
   if (sid) {
@@ -512,3 +519,61 @@ function abortConnection (socket, code) {
   }
   socket.destroy();
 }
+
+/* eslint-disable */
+
+/**
+ * From https://github.com/nodejs/node/blob/v8.4.0/lib/_http_common.js#L303-L354
+ *
+ * True if val contains an invalid field-vchar
+ *  field-value    = *( field-content / obs-fold )
+ *  field-content  = field-vchar [ 1*( SP / HTAB ) field-vchar ]
+ *  field-vchar    = VCHAR / obs-text
+ *
+ * checkInvalidHeaderChar() is currently designed to be inlinable by v8,
+ * so take care when making changes to the implementation so that the source
+ * code size does not exceed v8's default max_inlined_source_size setting.
+ **/
+var validHdrChars = [
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, // 0 - 15
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 16 - 31
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 32 - 47
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 48 - 63
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 64 - 79
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 80 - 95
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 96 - 111
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, // 112 - 127
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 128 ...
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1  // ... 255
+];
+
+function checkInvalidHeaderChar(val) {
+  val += '';
+  if (val.length < 1)
+    return false;
+  if (!validHdrChars[val.charCodeAt(0)])
+    return true;
+  if (val.length < 2)
+    return false;
+  if (!validHdrChars[val.charCodeAt(1)])
+    return true;
+  if (val.length < 3)
+    return false;
+  if (!validHdrChars[val.charCodeAt(2)])
+    return true;
+  if (val.length < 4)
+    return false;
+  if (!validHdrChars[val.charCodeAt(3)])
+    return true;
+  for (var i = 4; i < val.length; ++i) {
+    if (!validHdrChars[val.charCodeAt(i)])
+      return true;
+  }
+  return false;
+}