sslclient.cpp Example File

securesocketclient/sslclient.cpp
 /****************************************************************************
 **
 ** Copyright (C) 2017 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 "certificateinfo.h"
 #include "sslclient.h"

 #include "ui_sslclient.h"
 #include "ui_sslerrors.h"

 #include <QtCore>

 SslClient::SslClient(QWidget *parent)
     : QWidget(parent)
 {
     setupUi();
     setupSecureSocket();
 }

 SslClient::~SslClient()
 {
     delete form;
 }

 void SslClient::updateEnabledState()
 {
     const bool unconnected = socket->state() == QAbstractSocket::UnconnectedState;
     form->hostNameEdit->setReadOnly(!unconnected);
     form->hostNameEdit->setFocusPolicy(unconnected ? Qt::StrongFocus : Qt::NoFocus);
     form->hostNameLabel->setEnabled(unconnected);
     form->portBox->setEnabled(unconnected);
     form->portLabel->setEnabled(unconnected);
     form->connectButton->setEnabled(unconnected && !form->hostNameEdit->text().isEmpty());

     const bool connected = socket->state() == QAbstractSocket::ConnectedState;
     form->sessionOutput->setEnabled(connected);
     form->sessionInput->setEnabled(connected);
     form->sessionInputLabel->setEnabled(connected);
     form->sendButton->setEnabled(connected);
 }

 void SslClient::secureConnect()
 {
     socket->connectToHostEncrypted(form->hostNameEdit->text(), form->portBox->value());
     updateEnabledState();
 }

 void SslClient::socketStateChanged(QAbstractSocket::SocketState state)
 {
     if (executingDialog)
         return;

     updateEnabledState();

     if (state == QAbstractSocket::UnconnectedState) {
         form->sessionInput->clear();
         form->hostNameEdit->setPalette(QPalette());
         form->hostNameEdit->setFocus();
         form->cipherLabel->setText(tr("<none>"));
         padLock->hide();
     }
 }

 void SslClient::socketEncrypted()
 {
     form->sessionOutput->clear();
     form->sessionInput->setFocus();

     QPalette palette;
     palette.setColor(QPalette::Base, QColor(255, 255, 192));
     form->hostNameEdit->setPalette(palette);

     const QSslCipher cipher = socket->sessionCipher();
     const QString cipherInfo = QString("%1, %2 (%3/%4)").arg(cipher.authenticationMethod())
                                        .arg(cipher.name()).arg(cipher.usedBits())
                                        .arg(cipher.supportedBits());;
     form->cipherLabel->setText(cipherInfo);
     padLock->show();
 }

 void SslClient::socketReadyRead()
 {
     appendString(QString::fromUtf8(socket->readAll()));
 }

 void SslClient::sendData()
 {
     const QString input = form->sessionInput->text();
     appendString(input + '\n');
     socket->write(input.toUtf8() + "\r\n");
     form->sessionInput->clear();
 }

 void SslClient::socketError(QAbstractSocket::SocketError)
 {
     if (handlingSocketError)
         return;

     handlingSocketError = true;
     QMessageBox::critical(this, tr("Connection error"), socket->errorString());
     handlingSocketError = false;
 }

 void SslClient::sslErrors(const QList<QSslError> &errors)
 {
     QDialog errorDialog(this);
     Ui_SslErrors ui;
     ui.setupUi(&errorDialog);
     connect(ui.certificateChainButton, &QPushButton::clicked,
             this, &SslClient::displayCertificateInfo);

     for (const auto &error : errors)
         ui.sslErrorList->addItem(error.errorString());

     executingDialog = true;
     if (errorDialog.exec() == QDialog::Accepted)
         socket->ignoreSslErrors();
     executingDialog = false;

     // did the socket state change?
     if (socket->state() != QAbstractSocket::ConnectedState)
         socketStateChanged(socket->state());
 }

 void SslClient::displayCertificateInfo()
 {
     CertificateInfo info;
     info.setCertificateChain(socket->peerCertificateChain());
     info.exec();
 }

 void SslClient::setupUi()
 {
     if (form)
         return;

     form = new Ui_Form;
     form->setupUi(this);
     form->hostNameEdit->setSelection(0, form->hostNameEdit->text().size());
     form->sessionOutput->setHtml(tr("&lt;not connected&gt;"));

     connect(form->hostNameEdit, SIGNAL(textChanged(QString)),
             this, SLOT(updateEnabledState()));
     connect(form->connectButton, SIGNAL(clicked()),
             this, SLOT(secureConnect()));
     connect(form->sendButton, SIGNAL(clicked()),
             this, SLOT(sendData()));

     padLock = new QToolButton;
     padLock->setIcon(QIcon(":/encrypted.png"));
     connect(padLock, SIGNAL(clicked()), this, SLOT(displayCertificateInfo()));

 #if QT_CONFIG(cursor)
     padLock->setCursor(Qt::ArrowCursor);
 #endif
     padLock->setToolTip(tr("Display encryption details."));

     const int extent = form->hostNameEdit->height() - 2;
     padLock->resize(extent, extent);
     padLock->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Ignored);

     QHBoxLayout *layout = new QHBoxLayout(form->hostNameEdit);
     layout->setMargin(form->hostNameEdit->style()->pixelMetric(QStyle::PM_DefaultFrameWidth));
     layout->setSpacing(0);
     layout->addStretch();
     layout->addWidget(padLock);

     form->hostNameEdit->setLayout(layout);
     padLock->hide();
 }

 void SslClient::setupSecureSocket()
 {
     if (socket)
         return;

     socket = new QSslSocket(this);

     connect(socket, SIGNAL(stateChanged(QAbstractSocket::SocketState)),
             this, SLOT(socketStateChanged(QAbstractSocket::SocketState)));
     connect(socket, SIGNAL(encrypted()),
             this, SLOT(socketEncrypted()));
     connect(socket, SIGNAL(error(QAbstractSocket::SocketError)),
             this, SLOT(socketError(QAbstractSocket::SocketError)));
     connect(socket, SIGNAL(sslErrors(QList<QSslError>)),
             this, SLOT(sslErrors(QList<QSslError>)));
     connect(socket, SIGNAL(readyRead()),
             this, SLOT(socketReadyRead()));

 }

 void SslClient::appendString(const QString &line)
 {
     QTextCursor cursor(form->sessionOutput->textCursor());
     cursor.movePosition(QTextCursor::End);
     cursor.insertText(line);
     form->sessionOutput->verticalScrollBar()->setValue(form->sessionOutput->verticalScrollBar()->maximum());
 }