DTLS client - improve the example

- Remove redundant pingTimer.start() call (timer is not a single
shot timer and already started before this point in code).
- Use connected UDP sockets to show that it can work with QDtls.
- Replace (translated) string concatenations with formatted strings
  and 'arg' where needed.

Change-Id: I8dba54f43464a718062cd897d24f89b75b99f2a4
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
This commit is contained in:
Timur Pocheptsov 2018-06-22 10:04:11 +02:00
parent d27dd47ffa
commit ced0bd8068
2 changed files with 26 additions and 13 deletions

View File

@ -65,6 +65,7 @@ DtlsAssociation::DtlsAssociation(const QHostAddress &address, quint16 port,
connect(&crypto, &QDtls::handshakeTimeout, this, &DtlsAssociation::handshakeTimeout); connect(&crypto, &QDtls::handshakeTimeout, this, &DtlsAssociation::handshakeTimeout);
connect(&crypto, &QDtls::pskRequired, this, &DtlsAssociation::pskRequired); connect(&crypto, &QDtls::pskRequired, this, &DtlsAssociation::pskRequired);
socket.connectToHost(address.toString(), port);
connect(&socket, &QUdpSocket::readyRead, this, &DtlsAssociation::readyRead); connect(&socket, &QUdpSocket::readyRead, this, &DtlsAssociation::readyRead);
pingTimer.setInterval(5000); pingTimer.setInterval(5000);
@ -79,10 +80,22 @@ DtlsAssociation::~DtlsAssociation()
void DtlsAssociation::startHandshake() 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, {})) if (!crypto.doHandshake(&socket, {}))
emit errorMessage(name + tr(": failed to start a handshake - ") + crypto.dtlsErrorString()); emit errorMessage(tr("%1: failed to start a handshake - %2").arg(name, crypto.dtlsErrorString()));
else else
emit infoMessage(name + tr(": starting a handshake")); emit infoMessage(tr("%1: starting a handshake").arg(name));
}
void DtlsAssociation::udpSocketConnected()
{
emit infoMessage(tr("%1: UDP socket is now in ConnectedState, continue with handshake ...").arg(name));
startHandshake();
} }
void DtlsAssociation::readyRead() void DtlsAssociation::readyRead()
@ -90,7 +103,7 @@ void DtlsAssociation::readyRead()
QByteArray dgram(socket.pendingDatagramSize(), '\0'); QByteArray dgram(socket.pendingDatagramSize(), '\0');
const qint64 bytesRead = socket.readDatagram(dgram.data(), dgram.size()); const qint64 bytesRead = socket.readDatagram(dgram.data(), dgram.size());
if (bytesRead <= 0) { if (bytesRead <= 0) {
emit warningMessage(name + tr(": spurious read notification?")); emit warningMessage(tr("%1: spurious read notification?").arg(name));
return; return;
} }
@ -99,45 +112,44 @@ void DtlsAssociation::readyRead()
const QByteArray plainText = crypto.decryptDatagram(&socket, dgram); const QByteArray plainText = crypto.decryptDatagram(&socket, dgram);
if (plainText.size()) { if (plainText.size()) {
emit serverResponse(name, dgram, plainText); emit serverResponse(name, dgram, plainText);
pingTimer.start();
return; return;
} }
if (crypto.dtlsError() == QDtlsError::RemoteClosedConnectionError) { if (crypto.dtlsError() == QDtlsError::RemoteClosedConnectionError) {
emit errorMessage(name + tr(": shutdown alert received")); emit errorMessage(tr("%1: shutdown alert received").arg(name));
socket.close(); socket.close();
pingTimer.stop(); pingTimer.stop();
return; return;
} }
emit warningMessage(name + tr(": zero-length datagram received?")); emit warningMessage(tr("%1: zero-length datagram received?").arg(name));
} else { } else {
if (!crypto.doHandshake(&socket, dgram)) { if (!crypto.doHandshake(&socket, dgram)) {
emit errorMessage(name + tr(": handshake error - ") + crypto.dtlsErrorString()); emit errorMessage(tr("%1: handshake error - %2").arg(name, crypto.dtlsErrorString()));
return; return;
} }
if (crypto.connectionEncrypted()) { if (crypto.connectionEncrypted()) {
emit infoMessage(name + tr(": encrypted connection established!")); emit infoMessage(tr("%1: encrypted connection established!").arg(name));
pingTimer.start(); pingTimer.start();
pingTimeout(); pingTimeout();
} else { } else {
emit infoMessage(name + tr(": continuing with handshake ...")); emit infoMessage(tr("%1: continuing with handshake ...").arg(name));
} }
} }
} }
void DtlsAssociation::handshakeTimeout() void DtlsAssociation::handshakeTimeout()
{ {
emit warningMessage(name + tr(": handshake timeout, trying to re-transmit")); emit warningMessage(tr("%1: handshake timeout, trying to re-transmit").arg(name));
if (!crypto.handleTimeout(&socket)) if (!crypto.handleTimeout(&socket))
emit errorMessage(name + tr(": failed to re-transmit - ") + crypto.dtlsErrorString()); emit errorMessage(tr("%1: failed to re-transmit - %2").arg(name, crypto.dtlsErrorString()));
} }
void DtlsAssociation::pskRequired(QSslPreSharedKeyAuthenticator *auth) void DtlsAssociation::pskRequired(QSslPreSharedKeyAuthenticator *auth)
{ {
Q_ASSERT(auth); Q_ASSERT(auth);
emit infoMessage(name + tr(": providing pre-shared key ...")); emit infoMessage(tr("%1: providing pre-shared key ...").arg(name));
auth->setIdentity(name.toLatin1()); auth->setIdentity(name.toLatin1());
auth->setPreSharedKey(QByteArrayLiteral("\x1a\x2b\x3c\x4d\x5e\x6f")); auth->setPreSharedKey(QByteArrayLiteral("\x1a\x2b\x3c\x4d\x5e\x6f"));
} }
@ -147,7 +159,7 @@ void DtlsAssociation::pingTimeout()
static const QString message = QStringLiteral("I am %1, please, accept our ping %2"); 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()); const qint64 written = crypto.writeDatagramEncrypted(&socket, message.arg(name).arg(ping).toLatin1());
if (written <= 0) { if (written <= 0) {
emit errorMessage(name + tr(": failed to send a ping - ") + crypto.dtlsErrorString()); emit errorMessage(tr("%1: failed to send a ping - %2").arg(name, crypto.dtlsErrorString()));
pingTimer.stop(); pingTimer.stop();
return; return;
} }

View File

@ -76,6 +76,7 @@ signals:
private slots: private slots:
void udpSocketConnected();
void readyRead(); void readyRead();
void handshakeTimeout(); void handshakeTimeout();
void pskRequired(QSslPreSharedKeyAuthenticator *auth); void pskRequired(QSslPreSharedKeyAuthenticator *auth);