From 033a1a279311fd2eda02e4c90657542f688b5f8b Mon Sep 17 00:00:00 2001 From: Timur Pocheptsov Date: Fri, 23 Mar 2018 12:30:31 +0100 Subject: Add a secure UDP client example A simple application that establishes DTLS connection(s) and sends/receives datagrams. Class DtlsAssociation is essentially a QUdpSocket|QDtls pair: it initiates a handshake, handles timeouts and errors. After establishing an encrypted connection it sends messages to the server and processes responses. Task-number: QTBUG-67596 Change-Id: I92d481b7dfd2459e6a93c754b338a2e897a7feaf Reviewed-by: Timur Pocheptsov --- examples/network/secureudpclient/mainwindow.cpp | 181 ++++++++++++++++++++++++ 1 file changed, 181 insertions(+) create mode 100644 examples/network/secureudpclient/mainwindow.cpp (limited to 'examples/network/secureudpclient/mainwindow.cpp') diff --git a/examples/network/secureudpclient/mainwindow.cpp b/examples/network/secureudpclient/mainwindow.cpp new file mode 100644 index 0000000000..07c614cf3a --- /dev/null +++ b/examples/network/secureudpclient/mainwindow.cpp @@ -0,0 +1,181 @@ +/**************************************************************************** +** +** Copyright (C) 2018 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** 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 The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** BSD License Usage +** Alternatively, you may use this file under the terms of the BSD license +** as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of The Qt Company Ltd nor the names of its +** contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include +#include + +#include "addressdialog.h" +#include "association.h" +#include "mainwindow.h" +#include "ui_mainwindow.h" + +#include + +MainWindow::MainWindow(QWidget *parent) + : QMainWindow(parent), + ui(new Ui::MainWindow), + nameTemplate(QStringLiteral("Alice (clone number %1)")) +{ + ui->setupUi(this); + updateUi(); +} + +MainWindow::~MainWindow() +{ + delete ui; +} + +const QString colorizer(QStringLiteral("%2
")); + +void MainWindow::addErrorMessage(const QString &message) +{ + ui->clientMessages->insertHtml(colorizer.arg(QStringLiteral("Crimson"), message)); +} + +void MainWindow::addWarningMessage(const QString &message) +{ + ui->clientMessages->insertHtml(colorizer.arg(QStringLiteral("DarkOrange"), message)); +} + +void MainWindow::addInfoMessage(const QString &message) +{ + ui->clientMessages->insertHtml(colorizer.arg(QStringLiteral("DarkBlue"), message)); +} + +void MainWindow::addServerResponse(const QString &clientInfo, const QByteArray &datagram, + const QByteArray &plainText) +{ + static const QString messageColor = QStringLiteral("DarkMagenta"); + static const QString formatter = QStringLiteral("
---------------" + "
%1 received a DTLS datagram:
%2" + "
As plain text:
%3"); + + const QString html = formatter.arg(clientInfo, QString::fromUtf8(datagram.toHex(' ')), + QString::fromUtf8(plainText)); + ui->serverMessages->insertHtml(colorizer.arg(messageColor, html)); +} + +void MainWindow::on_connectButton_clicked() +{ + if (lookupId != -1) { + QHostInfo::abortHostLookup(lookupId); + lookupId = -1; + port = 0; + updateUi(); + return; + } + + AddressDialog dialog; + if (dialog.exec() != QDialog::Accepted) + return; + + const QString hostName = dialog.remoteName(); + if (hostName.isEmpty()) + return addWarningMessage(tr("Host name or address required to connect")); + + port = dialog.remotePort(); + QHostAddress remoteAddress; + if (remoteAddress.setAddress(hostName)) + return startNewConnection(remoteAddress); + + addInfoMessage(tr("Looking up the host ...")); + lookupId = QHostInfo::lookupHost(hostName, this, SLOT(lookupFinished(QHostInfo))); + updateUi(); +} + +void MainWindow::updateUi() +{ + ui->connectButton->setText(lookupId == -1 ? tr("Connect ...") : tr("Cancel lookup")); + ui->shutdownButton->setEnabled(connections.size() != 0); +} + +void MainWindow::lookupFinished(const QHostInfo &hostInfo) +{ + if (hostInfo.lookupId() != lookupId) + return; + + lookupId = -1; + updateUi(); + + if (hostInfo.error() != QHostInfo::NoError) { + addErrorMessage(hostInfo.errorString()); + return; + } + + const QList foundAddresses = hostInfo.addresses(); + if (foundAddresses.empty()) { + addWarningMessage(tr("Host not found")); + return; + } + + const auto remoteAddress = foundAddresses.at(0); + addInfoMessage(tr("Connecting to: %1").arg(remoteAddress.toString())); + startNewConnection(remoteAddress); +} + +void MainWindow::startNewConnection(const QHostAddress &address) +{ + AssocPtr newConnection(new DtlsAssociation(address, port, nameTemplate.arg(nextId))); + connect(newConnection.data(), &DtlsAssociation::errorMessage, this, &MainWindow::addErrorMessage); + connect(newConnection.data(), &DtlsAssociation::warningMessage, this, &MainWindow::addWarningMessage); + connect(newConnection.data(), &DtlsAssociation::infoMessage, this, &MainWindow::addInfoMessage); + connect(newConnection.data(), &DtlsAssociation::serverResponse, this, &MainWindow::addServerResponse); + connections.push_back(std::move(newConnection)); + connections.back()->startHandshake(); + updateUi(); + + ++nextId; +} + +void MainWindow::on_shutdownButton_clicked() +{ + connections.clear(); + updateUi(); +} -- cgit v1.2.3