QAbstractSocket / QSslSocket: add API to pause and resume

pause and resume is currently only supported upon emitting the
QSslSocket::sslErrors() signal. The API was added in QAbstractSocket to
also support QAbstractSocket::proxyAuthenticationRequired() in the
future.

This is the first patch to support that feature on the socket level,
another patch will follow to support sslErrors() and
authenticationRequired() in QNetworkAccessManager / QNetworkReply.

Task-number: QTBUG-19032
Change-Id: Ide2918268590ab9a01454ab26cb7fdca3dc840ab
Reviewed-by: Shane Kearns <ext-shane.2.kearns@nokia.com>

src/network/socket/qabstractsocket.cpp

@@ -425,6 +425,19 @@
     + ReuseAddressHint), and on Windows, its equivalent to ShareAddress.
 */
 
+/*! \enum QAbstractSocket::PauseMode
+    \since 5.0
+
+    This enum describes the behavior of when the socket should hold
+    back with continuing data transfer.
+
+    \value PauseNever Do not pause data transfer on the socket. This is the
+    default and matches the behaviour of Qt 4.
+    \value PauseOnNotify Pause data transfer on the socket upon receiving a
+    notification. The only notification currently supported is
+    QSslSocket::sslErrors().
+*/
+
 #include "qabstractsocket.h"
 #include "qabstractsocket_p.h"
 
@@ -529,6 +542,7 @@ QAbstractSocketPrivate::QAbstractSocketPrivate()
       abortCalled(false),
       closeCalled(false),
       pendingClose(false),
+      pauseMode(QAbstractSocket::PauseNever),
       port(0),
       localPort(0),
       peerPort(0),
@@ -1351,6 +1365,55 @@ QAbstractSocket::~QAbstractSocket()
         abort();
 }
 
+/*!
+    \since 5.0
+
+    Continues data transfer on the socket. This method should only be used
+    after the socket has been set to pause upon notifications and a
+    notification has been received.
+    The only notification currently supported is QSslSocket::sslErrors().
+    Calling this method if the socket is not paused results in undefined
+    behavior.
+
+    \sa pauseMode(), setPauseMode()
+*/
+void QAbstractSocket::resume()
+{
+    Q_D(QAbstractSocket);
+    d->resumeSocketNotifiers(this);
+}
+
+/*!
+    \since 5.0
+
+    Returns the pause mode of this socket.
+
+    \sa setPauseMode(), resume()
+*/
+QAbstractSocket::PauseMode QAbstractSocket::pauseMode() const
+{
+    return d_func()->pauseMode;
+}
+
+
+/*!
+    \since 5.0
+
+    Controls whether to pause upon receiving a notification. The only notification
+    currently supported is QSslSocket::sslErrors(). If set to PauseOnNotify,
+    data transfer on the socket will be paused and needs to be enabled explicitly
+    again by calling resume().
+    By default this option is set to PauseNever.
+    This option must be called before connecting to the server, otherwise it will
+    result in undefined behavior.
+
+    \sa pauseMode(), resume()
+*/
+void QAbstractSocket::setPauseMode(PauseMode pauseMode)
+{
+    d_func()->pauseMode = pauseMode;
+}
+
 /*!
     \since 5.0
 

src/network/socket/qabstractsocket.h

@@ -123,10 +123,18 @@ public:
         ReuseAddressHint = 0x4
     };
     Q_DECLARE_FLAGS(BindMode, BindFlag)
+    enum PauseMode {
+        PauseNever,
+        PauseOnNotify
+    };
 
     QAbstractSocket(SocketType socketType, QObject *parent);
     virtual ~QAbstractSocket();
 
+    virtual void resume(); // to continue after proxy authentication required, SSL errors etc.
+    PauseMode pauseMode() const;
+    void setPauseMode(PauseMode pauseMode);
+
     bool bind(const QHostAddress &address, quint16 port = 0, BindMode mode = DefaultForPlatform);
     bool bind(quint16 port = 0, BindMode mode = DefaultForPlatform);
 

src/network/socket/qabstractsocket_p.h

@@ -106,6 +106,8 @@ public:
     bool closeCalled;
     bool pendingClose;
 
+    QAbstractSocket::PauseMode pauseMode;
+
     QString hostName;
     quint16 port;
     QHostAddress host;

src/network/ssl/qsslsocket.cpp

@@ -355,6 +355,24 @@ QSslSocket::~QSslSocket()
     d->plainSocket = 0;
 }
 
+/*!
+    \reimp
+
+    \since 5.0
+
+    Continues data transfer on the socket after it has been paused. If
+    "setPauseMode(QAbstractSocket::PauseOnNotify);" has been called on
+    this socket and a sslErrors() signal is received, calling this method
+    is necessary for the socket to continue.
+
+    \sa QAbstractSocket::pauseMode(), QAbstractSocket::setPauseMode()
+*/
+void QSslSocket::resume()
+{
+    // continuing might emit signals, rather do this through the event loop
+    QMetaObject::invokeMethod(this, "_q_resumeImplementation", Qt::QueuedConnection);
+}
+
 /*!
     Starts an encrypted connection to the device \a hostName on \a
     port, using \a mode as the \l OpenMode. This is equivalent to
@@ -1860,6 +1878,7 @@ QSslSocketPrivate::QSslSocketPrivate()
     , readyReadEmittedPointer(0)
     , allowRootCertOnDemandLoading(true)
     , plainSocket(0)
+    , paused(false)
 {
     QSslConfigurationPrivate::deepCopyDefaultConfiguration(&configuration);
 }
@@ -2114,6 +2133,11 @@ void QSslSocketPrivate::resumeSocketNotifiers(QSslSocket *socket)
     QAbstractSocketPrivate::resumeSocketNotifiers(socket->d_func()->plainSocket);
 }
 
+bool QSslSocketPrivate::isPaused() const
+{
+    return paused;
+}
+
 /*!
     \internal
 */
@@ -2257,6 +2281,55 @@ void QSslSocketPrivate::_q_flushReadBuffer()
         transmit();
 }
 
+/*!
+    \internal
+*/
+void QSslSocketPrivate::_q_resumeImplementation()
+{
+    Q_Q(QSslSocket);
+    if (plainSocket)
+        plainSocket->resume();
+    paused = false;
+    if (!connectionEncrypted) {
+        if (verifyErrorsHaveBeenIgnored()) {
+            continueHandshake();
+        } else {
+            q->setErrorString(sslErrors.first().errorString());
+            q->setSocketError(QAbstractSocket::SslHandshakeFailedError);
+            emit q->error(QAbstractSocket::SslHandshakeFailedError);
+            plainSocket->disconnectFromHost();
+            return;
+        }
+    }
+    transmit();
+}
+
+/*!
+    \internal
+*/
+bool QSslSocketPrivate::verifyErrorsHaveBeenIgnored()
+{
+    bool doEmitSslError;
+    if (!ignoreErrorsList.empty()) {
+        // check whether the errors we got are all in the list of expected errors
+        // (applies only if the method QSslSocket::ignoreSslErrors(const QList<QSslError> &errors)
+        // was called)
+        doEmitSslError = false;
+        for (int a = 0; a < sslErrors.count(); a++) {
+            if (!ignoreErrorsList.contains(sslErrors.at(a))) {
+                doEmitSslError = true;
+                break;
+            }
+        }
+    } else {
+        // if QSslSocket::ignoreSslErrors(const QList<QSslError> &errors) was not called and
+        // we get an SSL error, emit a signal unless we ignored all errors (by calling
+        // QSslSocket::ignoreSslErrors() )
+        doEmitSslError = !ignoreAllSslErrors;
+    }
+    return !doEmitSslError;
+}
+
 /*!
     \internal
 */

src/network/ssl/qsslsocket.h

@@ -82,6 +82,7 @@ public:
 
     QSslSocket(QObject *parent = 0);
     ~QSslSocket();
+    void resume(); // to continue after proxy authentication required, SSL errors etc.
 
     // Autostarting the SSL client handshake.
     void connectToHostEncrypted(const QString &hostName, quint16 port, OpenMode mode = ReadWrite, NetworkLayerProtocol protocol = AnyIPProtocol);
@@ -211,6 +212,7 @@ private:
     Q_PRIVATE_SLOT(d_func(), void _q_bytesWrittenSlot(qint64))
     Q_PRIVATE_SLOT(d_func(), void _q_flushWriteBuffer())
     Q_PRIVATE_SLOT(d_func(), void _q_flushReadBuffer())
+    Q_PRIVATE_SLOT(d_func(), void _q_resumeImplementation())
     friend class QSslSocketBackendPrivate;
 };
 

src/network/ssl/qsslsocket_openssl.cpp

@@ -295,6 +295,7 @@ bool QSslSocketBackendPrivate::initSslContext()
     bool client = (mode == QSslSocket::SslClientMode);
 
     bool reinitialized = false;
+
 init_context:
     switch (configuration.protocol) {
     case QSsl::SslV2:
@@ -950,6 +951,9 @@ void QSslSocketBackendPrivate::transmit()
                 qDebug() << "QSslSocketBackendPrivate::transmit: connection lost";
 #endif
                 break;
+            } else if (paused) {
+                // just wait until the user continues
+                return;
             } else {
 #ifdef QSSLSOCKET_DEBUG
                 qDebug() << "QSslSocketBackendPrivate::transmit: encryption not done yet";
@@ -1188,46 +1192,25 @@ bool QSslSocketBackendPrivate::startHandshake()
         sslErrors = errors;
         emit q->sslErrors(errors);
 
-        bool doEmitSslError;
-        if (!ignoreErrorsList.empty()) {
-            // check whether the errors we got are all in the list of expected errors
-            // (applies only if the method QSslSocket::ignoreSslErrors(const QList<QSslError> &errors)
-            // was called)
-            doEmitSslError = false;
-            for (int a = 0; a < errors.count(); a++) {
-                if (!ignoreErrorsList.contains(errors.at(a))) {
-                    doEmitSslError = true;
-                    break;
-                }
-            }
-        } else {
-            // if QSslSocket::ignoreSslErrors(const QList<QSslError> &errors) was not called and
-            // we get an SSL error, emit a signal unless we ignored all errors (by calling
-            // QSslSocket::ignoreSslErrors() )
-            doEmitSslError = !ignoreAllSslErrors;
-        }
+        bool doEmitSslError = !verifyErrorsHaveBeenIgnored();
         // check whether we need to emit an SSL handshake error
         if (doVerifyPeer && doEmitSslError) {
-            q->setErrorString(sslErrors.first().errorString());
-            q->setSocketError(QAbstractSocket::SslHandshakeFailedError);
-            emit q->error(QAbstractSocket::SslHandshakeFailedError);
-            plainSocket->disconnectFromHost();
+            if (q->pauseMode() == QAbstractSocket::PauseOnNotify) {
+                pauseSocketNotifiers(q);
+                paused = true;
+            } else {
+                q->setErrorString(sslErrors.first().errorString());
+                q->setSocketError(QAbstractSocket::SslHandshakeFailedError);
+                emit q->error(QAbstractSocket::SslHandshakeFailedError);
+                plainSocket->disconnectFromHost();
+            }
             return false;
         }
     } else {
         sslErrors.clear();
     }
 
-    // if we have a max read buffer size, reset the plain socket's to 1k
-    if (readBufferMaxSize)
-        plainSocket->setReadBufferSize(1024);
-
-    connectionEncrypted = true;
-    emit q->encrypted();
-    if (autoStartHandshake && pendingClose) {
-        pendingClose = false;
-        q->disconnectFromHost();
-    }
+    continueHandshake();
     return true;
 }
 
@@ -1271,6 +1254,21 @@ QSslCipher QSslSocketBackendPrivate::sessionCipher() const
     return sessionCipher ? QSslCipher_from_SSL_CIPHER(sessionCipher) : QSslCipher();
 }
 
+void QSslSocketBackendPrivate::continueHandshake()
+{
+    Q_Q(QSslSocket);
+    // if we have a max read buffer size, reset the plain socket's to match
+    if (readBufferMaxSize)
+        plainSocket->setReadBufferSize(readBufferMaxSize);
+
+    connectionEncrypted = true;
+    emit q->encrypted();
+    if (autoStartHandshake && pendingClose) {
+        pendingClose = false;
+        q->disconnectFromHost();
+    }
+}
+
 QList<QSslCertificate> QSslSocketBackendPrivate::STACKOFX509_to_QSslCertificates(STACK_OF(X509) *x509)
 {
     ensureInitialized();

src/network/ssl/qsslsocket_openssl_p.h

@@ -115,6 +115,7 @@ public:
     void disconnectFromHost();
     void disconnected();
     QSslCipher sessionCipher() const;
+    void continueHandshake();
 
     Q_AUTOTEST_EXPORT static long setupOpenSslOptions(QSsl::SslProtocol protocol, QSsl::SslOptions sslOptions);
     static QSslCipher QSslCipher_from_SSL_CIPHER(SSL_CIPHER *cipher);

src/network/ssl/qsslsocket_p.h

@@ -149,6 +149,7 @@ public:
     void createPlainSocket(QIODevice::OpenMode openMode);
     static void pauseSocketNotifiers(QSslSocket*);
     static void resumeSocketNotifiers(QSslSocket*);
+    bool isPaused() const;
     void _q_connectedSlot();
     void _q_hostFoundSlot();
     void _q_disconnectedSlot();
@@ -158,6 +159,7 @@ public:
     void _q_bytesWrittenSlot(qint64);
     void _q_flushWriteBuffer();
     void _q_flushReadBuffer();
+    void _q_resumeImplementation();
 
     // Platform specific functions
     virtual void startClientEncryption() = 0;
@@ -166,6 +168,7 @@ public:
     virtual void disconnectFromHost() = 0;
     virtual void disconnected() = 0;
     virtual QSslCipher sessionCipher() const = 0;
+    virtual void continueHandshake() = 0;
 
 private:
     static bool ensureLibraryLoaded();
@@ -174,8 +177,10 @@ private:
     static bool s_libraryLoaded;
     static bool s_loadedCiphersAndCerts;
 protected:
+    bool verifyErrorsHaveBeenIgnored();
     static bool s_loadRootCertsOnDemand;
     static QList<QByteArray> unixRootCertDirectories();
+    bool paused;
 };
 
 QT_END_NAMESPACE

tests/auto/network/ssl/qsslsocket/tst_qsslsocket.cpp

@@ -192,10 +192,12 @@ private slots:
     void readFromClosedSocket();
     void writeBigChunk();
     void blacklistedCertificates();
-    void setEmptyDefaultConfiguration();
     void versionAccessors();
     void sslOptions();
     void encryptWithoutConnecting();
+    void resume_data();
+    void resume();
+    void setEmptyDefaultConfiguration(); // this test should be last
 
     static void exitLoop()
     {
@@ -2058,22 +2060,6 @@ void tst_QSslSocket::blacklistedCertificates()
     QCOMPARE(sslErrors.at(0).error(), QSslError::CertificateBlacklisted);
 }
 
-void tst_QSslSocket::setEmptyDefaultConfiguration()
-{
-    // used to produce a crash in QSslConfigurationPrivate::deepCopyDefaultConfiguration, QTBUG-13265
-
-    if (!QSslSocket::supportsSsl())
-        return;
-
-    QSslConfiguration emptyConf;
-    QSslConfiguration::setDefaultConfiguration(emptyConf);
-
-    QSslSocketPtr socket = newSocket();
-    connect(socket, SIGNAL(sslErrors(const QList<QSslError> &)), this, SLOT(ignoreErrorSlot()));
-    socket->connectToHostEncrypted(QtNetworkSettings::serverName(), 443);
-    QVERIFY2(!socket->waitForEncrypted(4000), qPrintable(socket->errorString()));
-}
-
 void tst_QSslSocket::versionAccessors()
 {
     if (!QSslSocket::supportsSsl())
@@ -2141,7 +2127,97 @@ void tst_QSslSocket::encryptWithoutConnecting()
     sock.startClientEncryption();
 }
 
+void tst_QSslSocket::resume_data()
+{
+    QTest::addColumn<bool>("ignoreErrorsAfterPause");
+    QTest::addColumn<QList<QSslError> >("errorsToIgnore");
+    QTest::addColumn<bool>("expectSuccess");
+
+    QList<QSslError> errorsList;
+    QTest::newRow("DoNotIgnoreErrors") << false << QList<QSslError>() << false;
+    QTest::newRow("ignoreAllErrors") << true << QList<QSslError>() << true;
+
+    QList<QSslCertificate> certs = QSslCertificate::fromPath(QLatin1String(SRCDIR "certs/qt-test-server-cacert.pem"));
+    QSslError rightError(QSslError::SelfSignedCertificate, certs.at(0));
+    QSslError wrongError(QSslError::SelfSignedCertificate);
+    errorsList.append(wrongError);
+    QTest::newRow("ignoreSpecificErrors-Wrong") << true << errorsList << false;
+    errorsList.clear();
+    errorsList.append(rightError);
+    QTest::newRow("ignoreSpecificErrors-Right") << true << errorsList << true;
+}
+
+void tst_QSslSocket::resume()
+{
+    // make sure the server certificate is not in the list of accepted certificates,
+    // we want to trigger the sslErrors signal
+    QSslSocket::setDefaultCaCertificates(QSslSocket::systemCaCertificates());
+
+    QFETCH(bool, ignoreErrorsAfterPause);
+    QFETCH(QList<QSslError>, errorsToIgnore);
+    QFETCH(bool, expectSuccess);
+
+    QSslSocket socket;
+    socket.setPauseMode(QAbstractSocket::PauseOnNotify);
+
+    QSignalSpy sslErrorSpy(&socket, SIGNAL(sslErrors(QList<QSslError>)));
+    QSignalSpy encryptedSpy(&socket, SIGNAL(encrypted()));
+    QSignalSpy errorSpy(&socket, SIGNAL(error(QAbstractSocket::SocketError)));
+
+    connect(&socket, SIGNAL(sslErrors(QList<QSslError>)), &QTestEventLoop::instance(), SLOT(exitLoop()));
+    connect(&socket, SIGNAL(encrypted()), &QTestEventLoop::instance(), SLOT(exitLoop()));
+    connect(&socket, SIGNAL(proxyAuthenticationRequired(QNetworkProxy,QAuthenticator*)),
+            this, SLOT(proxyAuthenticationRequired(QNetworkProxy,QAuthenticator*)));
+    connect(&socket, SIGNAL(error(QAbstractSocket::SocketError)), &QTestEventLoop::instance(), SLOT(exitLoop()));
+
+    socket.connectToHostEncrypted(QtNetworkSettings::serverName(), 993);
+    QTestEventLoop::instance().enterLoop(10);
+    QVERIFY(!QTestEventLoop::instance().timeout());
+    QCOMPARE(sslErrorSpy.count(), 1);
+    QCOMPARE(errorSpy.count(), 0);
+    QCOMPARE(encryptedSpy.count(), 0);
+    QVERIFY(!socket.isEncrypted());
+    if (ignoreErrorsAfterPause) {
+        if (errorsToIgnore.empty())
+            socket.ignoreSslErrors();
+        else
+            socket.ignoreSslErrors(errorsToIgnore);
+    }
+    socket.resume();
+    QTestEventLoop::instance().enterLoop(10);
+    QVERIFY(!QTestEventLoop::instance().timeout()); // quit by encrypted() or error() signal
+    if (expectSuccess) {
+        QCOMPARE(encryptedSpy.count(), 1);
+        QVERIFY(socket.isEncrypted());
+        QCOMPARE(errorSpy.count(), 0);
+        socket.disconnectFromHost();
+        QVERIFY(socket.waitForDisconnected(10000));
+    } else {
+        QCOMPARE(encryptedSpy.count(), 0);
+        QVERIFY(!socket.isEncrypted());
+        QCOMPARE(errorSpy.count(), 1);
+        QCOMPARE(socket.error(), QAbstractSocket::SslHandshakeFailedError);
+    }
+}
+
+void tst_QSslSocket::setEmptyDefaultConfiguration() // this test should be last, as it has some side effects
+{
+    // used to produce a crash in QSslConfigurationPrivate::deepCopyDefaultConfiguration, QTBUG-13265
+
+    if (!QSslSocket::supportsSsl())
+        return;
+
+    QSslConfiguration emptyConf;
+    QSslConfiguration::setDefaultConfiguration(emptyConf);
+
+    QSslSocketPtr socket = newSocket();
+    connect(socket, SIGNAL(sslErrors(const QList<QSslError> &)), this, SLOT(ignoreErrorSlot()));
+    socket->connectToHostEncrypted(QtNetworkSettings::serverName(), 443);
+    QVERIFY2(!socket->waitForEncrypted(4000), qPrintable(socket->errorString()));
+}
+
 #endif // QT_NO_OPENSSL
 
 QTEST_MAIN(tst_QSslSocket)
+
 #include "tst_qsslsocket.moc"