Revision control
++ // Copyright (C) 2018 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #include "server.h"
++
++ #include <algorithm>
++
++ namespace {
++
++ QString peer_info(const QHostAddress &address, quint16 port)
++ {
++ const static QString info = QStringLiteral("(%1:%2)");
++ return info.arg(address.toString()).arg(port);
++ }
++
++ QString connection_info(QDtls *connection)
++ {
++ QString info(DtlsServer::tr("Session cipher: "));
++ info += connection->sessionCipher().name();
++
++ info += DtlsServer::tr("; session protocol: ");
++ switch (connection->sessionProtocol()) {
++ case QSsl::DtlsV1_2:
++ info += DtlsServer::tr("DTLS 1.2.");
++ break;
++ default:
++ info += DtlsServer::tr("Unknown protocol.");
++ }
++
++ return info;
++ }
++
++ } // unnamed namespace
++
++ //! [1]
++ DtlsServer::DtlsServer()
++ {
++ connect(&serverSocket, &QAbstractSocket::readyRead, this, &DtlsServer::readyRead);
++
++ serverConfiguration = QSslConfiguration::defaultDtlsConfiguration();
++ serverConfiguration.setPreSharedKeyIdentityHint("Qt DTLS example server");
++ serverConfiguration.setPeerVerifyMode(QSslSocket::VerifyNone);
++ }
++ //! [1]
++
++ DtlsServer::~DtlsServer()
++ {
++ shutdown();
++ }
++
++ //! [2]
++ bool DtlsServer::listen(const QHostAddress &address, quint16 port)
++ {
++ if (address != serverSocket.localAddress() || port != serverSocket.localPort()) {
++ shutdown();
++ listening = serverSocket.bind(address, port);
++ if (!listening)
++ emit errorMessage(serverSocket.errorString());
++ } else {
++ listening = true;
++ }
++
++ return listening;
++ }
++ //! [2]
++
++ bool DtlsServer::isListening() const
++ {
++ return listening;
++ }
++
++ void DtlsServer::close()
++ {
++ listening = false;
++ }
++
++ void DtlsServer::readyRead()
++ {
++ //! [3]
++ const qint64 bytesToRead = serverSocket.pendingDatagramSize();
++ if (bytesToRead <= 0) {
++ emit warningMessage(tr("A spurious read notification"));
++ return;
++ }
++
++ QByteArray dgram(bytesToRead, Qt::Uninitialized);
++ QHostAddress peerAddress;
++ quint16 peerPort = 0;
++ const qint64 bytesRead = serverSocket.readDatagram(dgram.data(), dgram.size(),
++ &peerAddress, &peerPort);
++ if (bytesRead <= 0) {
++ emit warningMessage(tr("Failed to read a datagram: ") + serverSocket.errorString());
++ return;
++ }
++
++ dgram.resize(bytesRead);
++ //! [3]
++ //! [4]
++ if (peerAddress.isNull() || !peerPort) {
++ emit warningMessage(tr("Failed to extract peer info (address, port)"));
++ return;
++ }
++
++ const auto client = std::find_if(knownClients.begin(), knownClients.end(),
++ [&](const std::unique_ptr<QDtls> &connection){
++ return connection->peerAddress() == peerAddress
++ && connection->peerPort() == peerPort;
++ });
++ //! [4]
++
++ //! [5]
++ if (client == knownClients.end())
++ return handleNewConnection(peerAddress, peerPort, dgram);
++ //! [5]
++
++ //! [6]
++ if ((*client)->isConnectionEncrypted()) {
++ decryptDatagram(client->get(), dgram);
++ if ((*client)->dtlsError() == QDtlsError::RemoteClosedConnectionError)
++ knownClients.erase(client);
++ return;
++ }
++ //! [6]
++
++ //! [7]
++ doHandshake(client->get(), dgram);
++ //! [7]
++ }
++
++ //! [13]
++ void DtlsServer::pskRequired(QSslPreSharedKeyAuthenticator *auth)
++ {
++ Q_ASSERT(auth);
++
++ emit infoMessage(tr("PSK callback, received a client's identity: '%1'")
++ .arg(QString::fromLatin1(auth->identity())));
++ auth->setPreSharedKey(QByteArrayLiteral("\x1a\x2b\x3c\x4d\x5e\x6f"));
++ }
++ //! [13]
++
++ //! [8]
++ void DtlsServer::handleNewConnection(const QHostAddress &peerAddress,
++ quint16 peerPort, const QByteArray &clientHello)
++ {
++ if (!listening)
++ return;
++
++ const QString peerInfo = peer_info(peerAddress, peerPort);
++ if (cookieSender.verifyClient(&serverSocket, clientHello, peerAddress, peerPort)) {
++ emit infoMessage(peerInfo + tr(": verified, starting a handshake"));
++ //! [8]
++ //! [9]
++ std::unique_ptr<QDtls> newConnection{new QDtls{QSslSocket::SslServerMode}};
++ newConnection->setDtlsConfiguration(serverConfiguration);
++ newConnection->setPeer(peerAddress, peerPort);
++ newConnection->connect(newConnection.get(), &QDtls::pskRequired,
++ this, &DtlsServer::pskRequired);
++ knownClients.push_back(std::move(newConnection));
++ doHandshake(knownClients.back().get(), clientHello);
++ //! [9]
++ } else if (cookieSender.dtlsError() != QDtlsError::NoError) {
++ emit errorMessage(tr("DTLS error: ") + cookieSender.dtlsErrorString());
++ } else {
++ emit infoMessage(peerInfo + tr(": not verified yet"));
++ }
++ }
++
++ //! [11]
++ void DtlsServer::doHandshake(QDtls *newConnection, const QByteArray &clientHello)
++ {
++ const bool result = newConnection->doHandshake(&serverSocket, clientHello);
++ if (!result) {
++ emit errorMessage(newConnection->dtlsErrorString());
++ return;
++ }
++
++ const QString peerInfo = peer_info(newConnection->peerAddress(),
++ newConnection->peerPort());
++ switch (newConnection->handshakeState()) {
++ case QDtls::HandshakeInProgress:
++ emit infoMessage(peerInfo + tr(": handshake is in progress ..."));
++ break;
++ case QDtls::HandshakeComplete:
++ emit infoMessage(tr("Connection with %1 encrypted. %2")
++ .arg(peerInfo, connection_info(newConnection)));
++ break;
++ default:
++ Q_UNREACHABLE();
++ }
++ }
++ //! [11]
++
++ //! [12]
++ void DtlsServer::decryptDatagram(QDtls *connection, const QByteArray &clientMessage)
++ {
++ Q_ASSERT(connection->isConnectionEncrypted());
++
++ const QString peerInfo = peer_info(connection->peerAddress(), connection->peerPort());
++ const QByteArray dgram = connection->decryptDatagram(&serverSocket, clientMessage);
++ if (dgram.size()) {
++ emit datagramReceived(peerInfo, clientMessage, dgram);
++ connection->writeDatagramEncrypted(&serverSocket, tr("to %1: ACK").arg(peerInfo).toLatin1());
++ } else if (connection->dtlsError() == QDtlsError::NoError) {
++ emit warningMessage(peerInfo + ": " + tr("0 byte dgram, could be a re-connect attempt?"));
++ } else {
++ emit errorMessage(peerInfo + ": " + connection->dtlsErrorString());
++ }
++ }
++ //! [12]
++
++ //! [14]
++ void DtlsServer::shutdown()
++ {
++ for (const auto &connection : std::exchange(knownClients, {}))
++ connection->shutdown(&serverSocket);
++
++ serverSocket.close();
++ }
++ //! [14]