Revision control
++ // Copyright (C) 2018 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #include "association.h"
++
++ DtlsAssociation::DtlsAssociation(const QHostAddress &address, quint16 port,
++ const QString &connectionName)
++ : name(connectionName),
++ crypto(QSslSocket::SslClientMode)
++ {
++ //! [1]
++ auto configuration = QSslConfiguration::defaultDtlsConfiguration();
++ configuration.setPeerVerifyMode(QSslSocket::VerifyNone);
++ crypto.setPeer(address, port);
++ crypto.setDtlsConfiguration(configuration);
++ //! [1]
++
++ //! [2]
++ connect(&crypto, &QDtls::handshakeTimeout, this, &DtlsAssociation::handshakeTimeout);
++ //! [2]
++ connect(&crypto, &QDtls::pskRequired, this, &DtlsAssociation::pskRequired);
++ //! [3]
++ socket.connectToHost(address.toString(), port);
++ //! [3]
++ //! [13]
++ connect(&socket, &QUdpSocket::readyRead, this, &DtlsAssociation::readyRead);
++ //! [13]
++ //! [4]
++ pingTimer.setInterval(5000);
++ connect(&pingTimer, &QTimer::timeout, this, &DtlsAssociation::pingTimeout);
++ //! [4]
++ }
++
++ //! [12]
++ DtlsAssociation::~DtlsAssociation()
++ {
++ if (crypto.isConnectionEncrypted())
++ crypto.shutdown(&socket);
++ }
++ //! [12]
++
++ //! [5]
++ void DtlsAssociation::startHandshake()
++ {
++ if (socket.state() != QAbstractSocket::ConnectedState) {
++ emit infoMessage(tr("%1: connecting UDP socket first ...").arg(name));
++ connect(&socket, &QAbstractSocket::connected, this, &DtlsAssociation::udpSocketConnected);
++ return;
++ }
++
++ if (!crypto.doHandshake(&socket))
++ emit errorMessage(tr("%1: failed to start a handshake - %2").arg(name, crypto.dtlsErrorString()));
++ else
++ emit infoMessage(tr("%1: starting a handshake").arg(name));
++ }
++ //! [5]
++
++ void DtlsAssociation::udpSocketConnected()
++ {
++ emit infoMessage(tr("%1: UDP socket is now in ConnectedState, continue with handshake ...").arg(name));
++ startHandshake();
++ }
++
++ void DtlsAssociation::readyRead()
++ {
++ if (socket.pendingDatagramSize() <= 0) {
++ emit warningMessage(tr("%1: spurious read notification?").arg(name));
++ return;
++ }
++
++ //! [6]
++ QByteArray dgram(socket.pendingDatagramSize(), Qt::Uninitialized);
++ const qint64 bytesRead = socket.readDatagram(dgram.data(), dgram.size());
++ if (bytesRead <= 0) {
++ emit warningMessage(tr("%1: spurious read notification?").arg(name));
++ return;
++ }
++
++ dgram.resize(bytesRead);
++ //! [6]
++ //! [7]
++ if (crypto.isConnectionEncrypted()) {
++ const QByteArray plainText = crypto.decryptDatagram(&socket, dgram);
++ if (plainText.size()) {
++ emit serverResponse(name, dgram, plainText);
++ return;
++ }
++
++ if (crypto.dtlsError() == QDtlsError::RemoteClosedConnectionError) {
++ emit errorMessage(tr("%1: shutdown alert received").arg(name));
++ socket.close();
++ pingTimer.stop();
++ return;
++ }
++
++ emit warningMessage(tr("%1: zero-length datagram received?").arg(name));
++ } else {
++ //! [7]
++ //! [8]
++ if (!crypto.doHandshake(&socket, dgram)) {
++ emit errorMessage(tr("%1: handshake error - %2").arg(name, crypto.dtlsErrorString()));
++ return;
++ }
++ //! [8]
++
++ //! [9]
++ if (crypto.isConnectionEncrypted()) {
++ emit infoMessage(tr("%1: encrypted connection established!").arg(name));
++ pingTimer.start();
++ pingTimeout();
++ } else {
++ //! [9]
++ emit infoMessage(tr("%1: continuing with handshake ...").arg(name));
++ }
++ }
++ }
++
++ //! [11]
++ void DtlsAssociation::handshakeTimeout()
++ {
++ emit warningMessage(tr("%1: handshake timeout, trying to re-transmit").arg(name));
++ if (!crypto.handleTimeout(&socket))
++ emit errorMessage(tr("%1: failed to re-transmit - %2").arg(name, crypto.dtlsErrorString()));
++ }
++ //! [11]
++
++ //! [14]
++ void DtlsAssociation::pskRequired(QSslPreSharedKeyAuthenticator *auth)
++ {
++ Q_ASSERT(auth);
++
++ emit infoMessage(tr("%1: providing pre-shared key ...").arg(name));
++ auth->setIdentity(name.toLatin1());
++ auth->setPreSharedKey(QByteArrayLiteral("\x1a\x2b\x3c\x4d\x5e\x6f"));
++ }
++ //! [14]
++
++ //! [10]
++ void DtlsAssociation::pingTimeout()
++ {
++ static const QString message = QStringLiteral("I am %1, please, accept our ping %2");
++ const qint64 written = crypto.writeDatagramEncrypted(&socket, message.arg(name).arg(ping).toLatin1());
++ if (written <= 0) {
++ emit errorMessage(tr("%1: failed to send a ping - %2").arg(name, crypto.dtlsErrorString()));
++ pingTimer.stop();
++ return;
++ }
++
++ ++ping;
++ }
++ //! [10]