fix(dbPointer): fix utf8 bug for dbPointer

Author: daprahamian

lib/parser/deserializer.js

@@ -547,6 +547,9 @@ function deserializeObject(buffer, index, options, isArray) {
       )
         throw new Error('bad string length in bson');
       // Namespace
+      if (!validateUtf8(buffer, index, index + stringSize - 1)) {
+        throw new Error('Invalid UTF-8 string in BSON document');
+      }
       const namespace = buffer.toString('utf8', index, index + stringSize - 1);
       // Update parse index position
       index = index + stringSize;
@@ -558,11 +561,6 @@ function deserializeObject(buffer, index, options, isArray) {
 
       // Update the index
       index = index + 12;
-      for (i = 0; i < namespace.length; i++) {
-        if (namespace.charCodeAt(i) === 0xfffd) {
-          throw new Error('Invalid UTF-8 string in BSON document');
-        }
-      }
 
       // Upgrade to DBRef type
       object[name] = new DBRef(namespace, oid);

test/node/db_pointer_tests.js

@@ -0,0 +1,58 @@
+'use strict';
+
+const BSON = require('../../lib/bson');
+const expect = require('chai').expect;
+
+// 0x0C foo\0 \0\0\07 String.fromCharCode(0x41, 0x42, 0xfffd, 0x43, 0x44) 12
+const bsonSnippet = Buffer.from([
+  // Size
+  34,
+  0,
+  0,
+  0,
+  // BSON type for DBPointer
+  0x0c,
+
+  // CString Label Foo
+  0x66,
+  0x6f,
+  0x6f,
+  0,
+
+  // Length of UTF8 string "AB�CD"
+  8,
+  0,
+  0,
+  0,
+  0x41,
+  0x42,
+  0xef,
+  0xbf,
+  0xbd,
+  0x43,
+  0x44,
+  0,
+
+  // 12-bit pointer
+  1,
+  2,
+  3,
+  4,
+  5,
+  6,
+  7,
+  8,
+  9,
+  10,
+  11,
+  12,
+
+  // null terminator
+  0
+]);
+
+describe('dbpointer tests', function() {
+  it('can serialize and deserialize 0xFFFD in dbpointer name', function() {
+    expect(() => BSON.deserialize(bsonSnippet)).to.not.throw();
+  });
+});