Add user configurable mask generation

Created a QMaskGenerator abstract base class to serve as a basis for
user specific mask generators. Added the possibility to override the
default mask generation in QWebSocket.

Change-Id: Iaa02b44193f854d103b5f352617789175fe61f89
Reviewed-by: Kurt Pattyn <pattyn.kurt@gmail.com>

1 files changed, 91 insertions, 0 deletions

diff --git a/src/websockets/qmaskgenerator.cpp b/src/websockets/qmaskgenerator.cpp
new file mode 100644
index 0000000..9c678b5
--- /dev/null
+++ b/src/websockets/qmaskgenerator.cpp
@@ -0,0 +1,91 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtWebSockets module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+    \class QMaskGenerator
+    The QMaskGenerator class provides an abstract base for custom 32-bit mask generators.
+
+    The WebSockets specification as outlined in {http://tools.ietf.org/html/rfc6455}{RFC 6455}
+    requires that all communication from client to server must be masked. This is to prevent
+    malicious scripts to attack bad behaving proxies.
+    For more information about the importance of good masking,
+    see \l {http://w2spconf.com/2011/papers/websocket.pdf}.
+    By default QWebSocket uses the cryptographically insecure qrand() function.
+    The best measure against attacks mentioned in the document above,
+    is to use QWebSocket over a secure connection (\e wss://).
+    In general, always be careful to not have 3rd party script access to
+    a QWebSocket in your application.
+*/
+
+/*!
+    \fn bool QMaskGenerator::seed()
+
+    Initializes the QMaskGenerator by seeding the randomizer.
+    When seed() is not called, it depends on the specific implementation of a subclass if
+    a default seed is used or no seed is used at all.
+*/
+
+/*!
+    \fn quint32 QMaskGenerator::nextMask()
+
+    Returns a new random 32-bit mask. The randomness depends on the RNG used to created the
+    mask.
+*/
+
+#include "qmaskgenerator.h"
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    Creates a new QMaskGenerator object.
+ */
+QMaskGenerator::QMaskGenerator(QObject *parent) :
+    QObject(parent)
+{
+}
+
+/*!
+    Destroys the QMaskGenerator object.
+ */
+QMaskGenerator::~QMaskGenerator()
+{}
+
+QT_END_NAMESPACE