QSslSocket Class

QSslSocket *socket = new QSslSocket(this);
connect(socket, SIGNAL(encrypted()), this, SLOT(ready()));

socket->connectToHostEncrypted("imap.example.com", 993);

void SslServer::incomingConnection(qintptr socketDescriptor)
{
    QSslSocket *serverSocket = new QSslSocket;
    if (serverSocket->setSocketDescriptor(socketDescriptor)) {
        addPendingConnection(serverSocket);
        connect(serverSocket, &QSslSocket::encrypted, this, &SslServer::ready);
        serverSocket->startServerEncryption();
    } else {
        delete serverSocket;
    }
}

QSslSocket socket;
socket.connectToHostEncrypted("http.example.com", 443);
if (!socket.waitForEncrypted()) {
    qDebug() << socket.errorString();
    return false;
}

socket.write("GET / HTTP/1.0\r\n\r\n");
while (socket.waitForReadyRead())
    qDebug() << socket.readAll().data();

Member Function Documentation

QSslSocket::QSslSocket(QObject *parent = nullptr)

Constructs a QSslSocket object. parent is passed to QObject's constructor. The new socket's cipher suite is set to the one returned by the static method defaultCiphers().

[virtual] QSslSocket::~QSslSocket()

Destroys the QSslSocket.

void QSslSocket::abort()

Aborts the current connection and resets the socket. Unlike disconnectFromHost(), this function immediately closes the socket, clearing any pending data in the write buffer.

See also disconnectFromHost() and close().

void QSslSocket::addCaCertificate(const QSslCertificate &certificate)

Adds the certificate to this socket's CA certificate database. The CA certificate database is used by the socket during the handshake phase to validate the peer's certificate.

To add multiple certificates, use addCaCertificates().

See also caCertificates() and setCaCertificates().

bool QSslSocket::addCaCertificates(const QString &path, QSsl::EncodingFormat format = QSsl::Pem, QRegExp::PatternSyntax syntax = QRegExp::FixedString)

Searches all files in the path for certificates encoded in the specified format and adds them to this socket's CA certificate database. path must be a file or a pattern matching one or more files, as specified by syntax. Returns true if one or more certificates are added to the socket's CA certificate database; otherwise returns false.

The CA certificate database is used by the socket during the handshake phase to validate the peer's certificate.

For more precise control, use addCaCertificate().

See also addCaCertificate() and QSslCertificate::fromPath().

void QSslSocket::addCaCertificates(const QList<QSslCertificate> &certificates)

Adds the certificates to this socket's CA certificate database. The CA certificate database is used by the socket during the handshake phase to validate the peer's certificate.

For more precise control, use addCaCertificate().

See also caCertificates() and addDefaultCaCertificate().

[static] void QSslSocket::addDefaultCaCertificate(const QSslCertificate &certificate)

Adds certificate to the default CA certificate database. Each SSL socket's CA certificate database is initialized to the default CA certificate database.

See also defaultCaCertificates() and addCaCertificates().

[static] bool QSslSocket::addDefaultCaCertificates(const QString &path, QSsl::EncodingFormat encoding = QSsl::Pem, QRegExp::PatternSyntax syntax = QRegExp::FixedString)

Searches all files in the path for certificates with the specified encoding and adds them to the default CA certificate database. path can be an explicit file, or it can contain wildcards in the format specified by syntax. Returns true if any CA certificates are added to the default database.

Each SSL socket's CA certificate database is initialized to the default CA certificate database.

See also defaultCaCertificates(), addCaCertificates(), and addDefaultCaCertificate().

[static] void QSslSocket::addDefaultCaCertificates(const QList<QSslCertificate> &certificates)

Adds certificates to the default CA certificate database. Each SSL socket's CA certificate database is initialized to the default CA certificate database.

See also defaultCaCertificates() and addCaCertificates().

[override virtual] bool QSslSocket::atEnd() const

Reimplemented from QAbstractSocket::atEnd().

[override virtual] qint64 QSslSocket::bytesAvailable() const

Reimplemented from QAbstractSocket::bytesAvailable().

Returns the number of decrypted bytes that are immediately available for reading.

[override virtual] qint64 QSslSocket::bytesToWrite() const

Reimplemented from QAbstractSocket::bytesToWrite().

Returns the number of unencrypted bytes that are waiting to be encrypted and written to the network.

[override virtual] bool QSslSocket::canReadLine() const

Reimplemented from QAbstractSocket::canReadLine().

Returns true if you can read one while line (terminated by a single ASCII '\n' character) of decrypted characters; otherwise, false is returned.

[override virtual] void QSslSocket::close()

Reimplemented from QAbstractSocket::close().

void QSslSocket::connectToHostEncrypted(const QString &hostName, quint16 port, QIODevice::OpenMode mode, QAbstractSocket::NetworkLayerProtocol protocol = AnyIPProtocol)

Starts an encrypted connection to the device hostName on port, using mode as the OpenMode. This is equivalent to calling connectToHost() to establish the connection, followed by a call to startClientEncryption(). The protocol parameter can be used to specify which network protocol to use (eg. IPv4 or IPv6).

QSslSocket first enters the HostLookupState. Then, after entering either the event loop or one of the waitFor...() functions, it enters the ConnectingState, emits connected(), and then initiates the SSL client handshake. At each state change, QSslSocket emits signal stateChanged().

After initiating the SSL client handshake, if the identity of the peer can't be established, signal sslErrors() is emitted. If you want to ignore the errors and continue connecting, you must call ignoreSslErrors(), either from inside a slot function connected to the sslErrors() signal, or prior to entering encrypted mode. If ignoreSslErrors() is not called, the connection is dropped, signal disconnected() is emitted, and QSslSocket returns to the UnconnectedState.

If the SSL handshake is successful, QSslSocket emits encrypted().

QSslSocket socket;
connect(&socket, SIGNAL(encrypted()), receiver, SLOT(socketEncrypted()));

socket.connectToHostEncrypted("imap", 993);
socket->write("1 CAPABILITY\r\n");

Note: The example above shows that text can be written to the socket immediately after requesting the encrypted connection, before the encrypted() signal has been emitted. In such cases, the text is queued in the object and written to the socket after the connection is established and the encrypted() signal has been emitted.

The default for mode is ReadWrite.

If you want to create a QSslSocket on the server side of a connection, you should instead call startServerEncryption() upon receiving the incoming connection through QTcpServer.

See also connectToHost(), startClientEncryption(), waitForConnected(), and waitForEncrypted().

void QSslSocket::connectToHostEncrypted(const QString &hostName, quint16 port, const QString &sslPeerName, QIODevice::OpenMode mode, QAbstractSocket::NetworkLayerProtocol protocol = AnyIPProtocol)

This is an overloaded function.

In addition to the original behaviour of connectToHostEncrypted, this overloaded method enables the usage of a different hostname (sslPeerName) for the certificate validation instead of the one used for the TCP connection (hostName).

This function was introduced in Qt 4.6.

See also connectToHostEncrypted().

[signal] void QSslSocket::encrypted()

This signal is emitted when QSslSocket enters encrypted mode. After this signal has been emitted, QSslSocket::isEncrypted() will return true, and all further transmissions on the socket will be encrypted.

See also QSslSocket::connectToHostEncrypted() and QSslSocket::isEncrypted().

qint64 QSslSocket::encryptedBytesAvailable() const

Returns the number of encrypted bytes that are awaiting decryption. Normally, this function will return 0 because QSslSocket decrypts its incoming data as soon as it can.

This function was introduced in Qt 4.4.

qint64 QSslSocket::encryptedBytesToWrite() const

Returns the number of encrypted bytes that are waiting to be written to the network.

This function was introduced in Qt 4.4.

[signal] void QSslSocket::encryptedBytesWritten(qint64 written)

This signal is emitted when QSslSocket writes its encrypted data to the network. The written parameter contains the number of bytes that were successfully written.

This function was introduced in Qt 4.4.

See also QIODevice::bytesWritten().

bool QSslSocket::flush()

This function writes as much as possible from the internal write buffer to the underlying network socket, without blocking. If any data was written, this function returns true; otherwise false is returned.

Call this function if you need QSslSocket to start sending buffered data immediately. The number of bytes successfully written depends on the operating system. In most cases, you do not need to call this function, because QAbstractSocket will start sending data automatically once control goes back to the event loop. In the absence of an event loop, call waitForBytesWritten() instead.

See also write() and waitForBytesWritten().

[slot] void QSslSocket::ignoreSslErrors()

This slot tells QSslSocket to ignore errors during QSslSocket's handshake phase and continue connecting. If you want to continue with the connection even if errors occur during the handshake phase, then you must call this slot, either from a slot connected to sslErrors(), or before the handshake phase. If you don't call this slot, either in response to errors or before the handshake, the connection will be dropped after the sslErrors() signal has been emitted.

If there are no errors during the SSL handshake phase (i.e., the identity of the peer is established with no problems), QSslSocket will not emit the sslErrors() signal, and it is unnecessary to call this function.

Warning: Be sure to always let the user inspect the errors reported by the sslErrors() signal, and only call this method upon confirmation from the user that proceeding is ok. If there are unexpected errors, the connection should be aborted. Calling this method without inspecting the actual errors will most likely pose a security risk for your application. Use it with great care!

See also sslErrors().

void QSslSocket::ignoreSslErrors(const QList<QSslError> &errors)

This is an overloaded function.

This method tells QSslSocket to ignore only the errors given in errors.

Note: Because most SSL errors are associated with a certificate, for most of them you must set the expected certificate this SSL error is related to. If, for instance, you want to connect to a server that uses a self-signed certificate, consider the following snippet:

QList<QSslCertificate> cert = QSslCertificate::fromPath(QLatin1String("server-certificate.pem"));
QSslError error(QSslError::SelfSignedCertificate, cert.at(0));
QList<QSslError> expectedSslErrors;
expectedSslErrors.append(error);

QSslSocket socket;
socket.ignoreSslErrors(expectedSslErrors);
socket.connectToHostEncrypted("server.tld", 443);

Multiple calls to this function will replace the list of errors that were passed in previous calls. You can clear the list of errors you want to ignore by calling this function with an empty list.

This function was introduced in Qt 4.6.

See also sslErrors().

bool QSslSocket::isEncrypted() const

Returns true if the socket is encrypted; otherwise, false is returned.

An encrypted socket encrypts all data that is written by calling write() or putChar() before the data is written to the network, and decrypts all incoming data as the data is received from the network, before you call read(), readLine() or getChar().

QSslSocket emits encrypted() when it enters encrypted mode.

You can call sessionCipher() to find which cryptographic cipher is used to encrypt and decrypt your data.

See also mode().

QSslCertificate QSslSocket::localCertificate() const

Returns the socket's local certificate, or an empty certificate if no local certificate has been assigned.

See also setLocalCertificate() and privateKey().

QList<QSslCertificate> QSslSocket::localCertificateChain() const

Returns the socket's local certificate chain, or an empty list if no local certificates have been assigned.

This function was introduced in Qt 5.1.

See also setLocalCertificateChain().

QSslSocket::SslMode QSslSocket::mode() const

Returns the current mode for the socket; either UnencryptedMode, where QSslSocket behaves identially to QTcpSocket, or one of SslClientMode or SslServerMode, where the client is either negotiating or in encrypted mode.

When the mode changes, QSslSocket emits modeChanged()

See also SslMode.

[signal] void QSslSocket::modeChanged(QSslSocket::SslMode mode)

This signal is emitted when QSslSocket changes from QSslSocket::UnencryptedMode to either QSslSocket::SslClientMode or QSslSocket::SslServerMode. mode is the new mode.

See also QSslSocket::mode().

QSslCertificate QSslSocket::peerCertificate() const

Returns the peer's digital certificate (i.e., the immediate certificate of the host you are connected to), or a null certificate, if the peer has not assigned a certificate.

The peer certificate is checked automatically during the handshake phase, so this function is normally used to fetch the certificate for display or for connection diagnostic purposes. It contains information about the peer, including its host name, the certificate issuer, and the peer's public key.

Because the peer certificate is set during the handshake phase, it is safe to access the peer certificate from a slot connected to the sslErrors() signal or the encrypted() signal.

If a null certificate is returned, it can mean the SSL handshake failed, or it can mean the host you are connected to doesn't have a certificate, or it can mean there is no connection.

If you want to check the peer's complete chain of certificates, use peerCertificateChain() to get them all at once.

See also peerCertificateChain().

QList<QSslCertificate> QSslSocket::peerCertificateChain() const

Returns the peer's chain of digital certificates, or an empty list of certificates.

Peer certificates are checked automatically during the handshake phase. This function is normally used to fetch certificates for display, or for performing connection diagnostics. Certificates contain information about the peer and the certificate issuers, including host name, issuer names, and issuer public keys.

The peer certificates are set in QSslSocket during the handshake phase, so it is safe to call this function from a slot connected to the sslErrors() signal or the encrypted() signal.

If an empty list is returned, it can mean the SSL handshake failed, or it can mean the host you are connected to doesn't have a certificate, or it can mean there is no connection.

If you want to get only the peer's immediate certificate, use peerCertificate().

See also peerCertificate().

int QSslSocket::peerVerifyDepth() const

Returns the maximum number of certificates in the peer's certificate chain to be checked during the SSL handshake phase, or 0 (the default) if no maximum depth has been set, indicating that the whole certificate chain should be checked.

The certificates are checked in issuing order, starting with the peer's own certificate, then its issuer's certificate, and so on.

This function was introduced in Qt 4.4.

See also setPeerVerifyDepth() and peerVerifyMode().

[signal] void QSslSocket::peerVerifyError(const QSslError &error)

QSslSocket can emit this signal several times during the SSL handshake, before encryption has been established, to indicate that an error has occurred while establishing the identity of the peer. The error is usually an indication that QSslSocket is unable to securely identify the peer.

This signal provides you with an early indication when something's wrong. By connecting to this signal, you can manually choose to tear down the connection from inside the connected slot before the handshake has completed. If no action is taken, QSslSocket will proceed to emitting QSslSocket::sslErrors().

This function was introduced in Qt 4.4.

See also sslErrors().

QSslSocket::PeerVerifyMode QSslSocket::peerVerifyMode() const

Returns the socket's verify mode. This mode decides whether QSslSocket should request a certificate from the peer (i.e., the client requests a certificate from the server, or a server requesting a certificate from the client), and whether it should require that this certificate is valid.

The default mode is AutoVerifyPeer, which tells QSslSocket to use VerifyPeer for clients and QueryPeer for servers.

This function was introduced in Qt 4.4.

See also setPeerVerifyMode(), peerVerifyDepth(), and mode().

QString QSslSocket::peerVerifyName() const

Returns the different hostname for the certificate validation, as set by setPeerVerifyName or by connectToHostEncrypted.

This function was introduced in Qt 4.8.

See also setPeerVerifyName() and connectToHostEncrypted().

[signal] void QSslSocket::preSharedKeyAuthenticationRequired(QSslPreSharedKeyAuthenticator *authenticator)

QSslSocket emits this signal when it negotiates a PSK ciphersuite, and therefore a PSK authentication is then required.

When using PSK, the client must send to the server a valid identity and a valid pre shared key, in order for the SSL handshake to continue. Applications can provide this information in a slot connected to this signal, by filling in the passed authenticator object according to their needs.

Note: Ignoring this signal, or failing to provide the required credentials, will cause the handshake to fail, and therefore the connection to be aborted.

Note: The authenticator object is owned by the socket and must not be deleted by the application.

This function was introduced in Qt 5.5.

See also QSslPreSharedKeyAuthenticator.

QSslKey QSslSocket::privateKey() const

Returns this socket's private key.

See also setPrivateKey() and localCertificate().

QSsl::SslProtocol QSslSocket::protocol() const

Returns the socket's SSL protocol. By default, QSsl::SecureProtocols is used.

See also setProtocol().

[override virtual protected] qint64 QSslSocket::readData(char *data, qint64 maxlen)

Reimplemented from QAbstractSocket::readData().

[override virtual] void QSslSocket::resume()

Reimplemented from QAbstractSocket::resume().

Continues data transfer on the socket after it has been paused. If "setPauseMode(QAbstractSocket::PauseOnSslErrors);" has been called on this socket and a sslErrors() signal is received, calling this method is necessary for the socket to continue.

This function was introduced in Qt 5.0.

See also QAbstractSocket::pauseMode() and QAbstractSocket::setPauseMode().

QSslCipher QSslSocket::sessionCipher() const

Returns the socket's cryptographic cipher, or a null cipher if the connection isn't encrypted. The socket's cipher for the session is set during the handshake phase. The cipher is used to encrypt and decrypt data transmitted through the socket.

QSslSocket also provides functions for setting the ordered list of ciphers from which the handshake phase will eventually select the session cipher. This ordered list must be in place before the handshake phase begins.

See also ciphers(), setCiphers(), setDefaultCiphers(), defaultCiphers(), and supportedCiphers().

QSsl::SslProtocol QSslSocket::sessionProtocol() const

Returns the socket's SSL/TLS protocol or UnknownProtocol if the connection isn't encrypted. The socket's protocol for the session is set during the handshake phase.

This function was introduced in Qt 5.4.

See also protocol() and setProtocol().

void QSslSocket::setLocalCertificate(const QSslCertificate &certificate)

Sets the socket's local certificate to certificate. The local certificate is necessary if you need to confirm your identity to the peer. It is used together with the private key; if you set the local certificate, you must also set the private key.

The local certificate and private key are always necessary for server sockets, but are also rarely used by client sockets if the server requires the client to authenticate.

Note: Secure Transport SSL backend on macOS may update the default keychain (the default is probably your login keychain) by importing your local certificates and keys. This can also result in system dialogs showing up and asking for permission when your application is using these private keys. If such behavior is undesired, set the QT_SSL_USE_TEMPORARY_KEYCHAIN environment variable to a non-zero value; this will prompt QSslSocket to use its own temporary keychain.

See also localCertificate() and setPrivateKey().

void QSslSocket::setLocalCertificate(const QString &path, QSsl::EncodingFormat format = QSsl::Pem)

This is an overloaded function.

Sets the socket's local certificate to the first one found in file path, which is parsed according to the specified format.

void QSslSocket::setLocalCertificateChain(const QList<QSslCertificate> &localChain)

Sets the certificate chain to be presented to the peer during the SSL handshake to be localChain.

This function was introduced in Qt 5.1.

See also localCertificateChain() and QSslConfiguration::setLocalCertificateChain().

void QSslSocket::setPeerVerifyDepth(int depth)

Sets the maximum number of certificates in the peer's certificate chain to be checked during the SSL handshake phase, to depth. Setting a depth of 0 means that no maximum depth is set, indicating that the whole certificate chain should be checked.

The certificates are checked in issuing order, starting with the peer's own certificate, then its issuer's certificate, and so on.

This function was introduced in Qt 4.4.

See also peerVerifyDepth() and setPeerVerifyMode().

void QSslSocket::setPeerVerifyMode(QSslSocket::PeerVerifyMode mode)

Sets the socket's verify mode to mode. This mode decides whether QSslSocket should request a certificate from the peer (i.e., the client requests a certificate from the server, or a server requesting a certificate from the client), and whether it should require that this certificate is valid.

The default mode is AutoVerifyPeer, which tells QSslSocket to use VerifyPeer for clients and QueryPeer for servers.

Setting this mode after encryption has started has no effect on the current connection.

This function was introduced in Qt 4.4.

See also peerVerifyMode(), setPeerVerifyDepth(), and mode().

void QSslSocket::setPeerVerifyName(const QString &hostName)

Sets a different host name, given by hostName, for the certificate validation instead of the one used for the TCP connection.

This function was introduced in Qt 4.8.

See also peerVerifyName() and connectToHostEncrypted().

void QSslSocket::setPrivateKey(const QSslKey &key)

Sets the socket's private key to key. The private key and the local certificate are used by clients and servers that must prove their identity to SSL peers.

Both the key and the local certificate are required if you are creating an SSL server socket. If you are creating an SSL client socket, the key and local certificate are required if your client must identify itself to an SSL server.

See also privateKey() and setLocalCertificate().

void QSslSocket::setPrivateKey(const QString &fileName, QSsl::KeyAlgorithm algorithm = QSsl::Rsa, QSsl::EncodingFormat format = QSsl::Pem, const QByteArray &passPhrase = QByteArray())

This is an overloaded function.

Reads the string in file fileName and decodes it using a specified algorithm and encoding format to construct an SSL key. If the encoded key is encrypted, passPhrase is used to decrypt it.

The socket's private key is set to the constructed key. The private key and the local certificate are used by clients and servers that must prove their identity to SSL peers.

Both the key and the local certificate are required if you are creating an SSL server socket. If you are creating an SSL client socket, the key and local certificate are required if your client must identify itself to an SSL server.

See also privateKey() and setLocalCertificate().

void QSslSocket::setProtocol(QSsl::SslProtocol protocol)

Sets the socket's SSL protocol to protocol. This will affect the next initiated handshake; calling this function on an already-encrypted socket will not affect the socket's protocol.

See also protocol().

[override virtual] void QSslSocket::setReadBufferSize(qint64 size)

Reimplemented from QAbstractSocket::setReadBufferSize().

Sets the size of QSslSocket's internal read buffer to be size bytes.

This function was introduced in Qt 4.4.

[override virtual] bool QSslSocket::setSocketDescriptor(qintptr socketDescriptor, QAbstractSocket::SocketState state, QIODevice::OpenMode openMode)

Reimplemented from QAbstractSocket::setSocketDescriptor().

Initializes QSslSocket with the native socket descriptor socketDescriptor. Returns true if socketDescriptor is accepted as a valid socket descriptor; otherwise returns false. The socket is opened in the mode specified by openMode, and enters the socket state specified by state.

Note: It is not possible to initialize two sockets with the same native socket descriptor.

See also socketDescriptor().

[override virtual] void QSslSocket::setSocketOption(QAbstractSocket::SocketOption option, const QVariant &value)

Reimplemented from QAbstractSocket::setSocketOption().

Sets the given option to the value described by value.

This function was introduced in Qt 4.6.

See also socketOption().

void QSslSocket::setSslConfiguration(const QSslConfiguration &configuration)

Sets the socket's SSL configuration to be the contents of configuration. This function sets the local certificate, the ciphers, the private key and the CA certificates to those stored in configuration.

It is not possible to set the SSL-state related fields.

This function was introduced in Qt 4.4.

See also sslConfiguration(), setLocalCertificate(), setPrivateKey(), setCaCertificates(), and setCiphers().

[override virtual] QVariant QSslSocket::socketOption(QAbstractSocket::SocketOption option)

Reimplemented from QAbstractSocket::socketOption().

Returns the value of the option option.

This function was introduced in Qt 4.6.

See also setSocketOption().

QSslConfiguration QSslSocket::sslConfiguration() const

Returns the socket's SSL configuration state. The default SSL configuration of a socket is to use the default ciphers, default CA certificates, no local private key or certificate.

The SSL configuration also contains fields that can change with time without notice.

This function was introduced in Qt 4.4.

See also setSslConfiguration(), localCertificate(), peerCertificate(), peerCertificateChain(), sessionCipher(), privateKey(), ciphers(), and caCertificates().

QList<QSslError> QSslSocket::sslErrors() const

Returns a list of the last SSL errors that occurred. This is the same list as QSslSocket passes via the sslErrors() signal. If the connection has been encrypted with no errors, this function will return an empty list.

See also connectToHostEncrypted().

[signal] void QSslSocket::sslErrors(const QList<QSslError> &errors)

QSslSocket emits this signal after the SSL handshake to indicate that one or more errors have occurred while establishing the identity of the peer. The errors are usually an indication that QSslSocket is unable to securely identify the peer. Unless any action is taken, the connection will be dropped after this signal has been emitted.

If you want to continue connecting despite the errors that have occurred, you must call QSslSocket::ignoreSslErrors() from inside a slot connected to this signal. If you need to access the error list at a later point, you can call sslErrors() (without arguments).

errors contains one or more errors that prevent QSslSocket from verifying the identity of the peer.

Note: You cannot use Qt::QueuedConnection when connecting to this signal, or calling QSslSocket::ignoreSslErrors() will have no effect.

Note: Signal sslErrors is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(sslSocket, QOverload<const QList<QSslError> &>::of(&QSslSocket::sslErrors),
    [=](const QList<QSslError> &errors){ /* ... */ });

See also peerVerifyError().

[static] long QSslSocket::sslLibraryBuildVersionNumber()

Returns the version number of the SSL library in use at compile time. If no SSL support is available then this will return an undefined value.

This function was introduced in Qt 5.4.

See also sslLibraryVersionNumber().

[static] QString QSslSocket::sslLibraryBuildVersionString()

Returns the version string of the SSL library in use at compile time. If no SSL support is available then this will return an empty value.

This function was introduced in Qt 5.4.

See also sslLibraryVersionString().

[static] long QSslSocket::sslLibraryVersionNumber()

Returns the version number of the SSL library in use. Note that this is the version of the library in use at run-time not compile time. If no SSL support is available then this will return an undefined value.

This function was introduced in Qt 5.0.

[static] QString QSslSocket::sslLibraryVersionString()

Returns the version string of the SSL library in use. Note that this is the version of the library in use at run-time not compile time. If no SSL support is available then this will return an empty value.

This function was introduced in Qt 5.0.

[slot] void QSslSocket::startClientEncryption()

Starts a delayed SSL handshake for a client connection. This function can be called when the socket is in the ConnectedState but still in the UnencryptedMode. If it is not yet connected, or if it is already encrypted, this function has no effect.

Clients that implement STARTTLS functionality often make use of delayed SSL handshakes. Most other clients can avoid calling this function directly by using connectToHostEncrypted() instead, which automatically performs the handshake.

See also connectToHostEncrypted() and startServerEncryption().

[slot] void QSslSocket::startServerEncryption()

Starts a delayed SSL handshake for a server connection. This function can be called when the socket is in the ConnectedState but still in UnencryptedMode. If it is not connected or it is already encrypted, the function has no effect.

For server sockets, calling this function is the only way to initiate the SSL handshake. Most servers will call this function immediately upon receiving a connection, or as a result of having received a protocol-specific command to enter SSL mode (e.g, the server may respond to receiving the string "STARTTLS\r\n" by calling this function).

The most common way to implement an SSL server is to create a subclass of QTcpServer and reimplement QTcpServer::incomingConnection(). The returned socket descriptor is then passed to QSslSocket::setSocketDescriptor().

See also connectToHostEncrypted() and startClientEncryption().

[static] bool QSslSocket::supportsSsl()

Returns true if this platform supports SSL; otherwise, returns false. If the platform doesn't support SSL, the socket will fail in the connection phase.

[override virtual] bool QSslSocket::waitForBytesWritten(int msecs = 30000)

Reimplemented from QAbstractSocket::waitForBytesWritten().

[override virtual] bool QSslSocket::waitForConnected(int msecs = 30000)

Reimplemented from QAbstractSocket::waitForConnected().

Waits until the socket is connected, or msecs milliseconds, whichever happens first. If the connection has been established, this function returns true; otherwise it returns false.

See also QAbstractSocket::waitForConnected().

[override virtual] bool QSslSocket::waitForDisconnected(int msecs = 30000)

Reimplemented from QAbstractSocket::waitForDisconnected().

Waits until the socket has disconnected or msecs milliseconds, whichever comes first. If the connection has been disconnected, this function returns true; otherwise it returns false.

See also QAbstractSocket::waitForDisconnected().

bool QSslSocket::waitForEncrypted(int msecs = 30000)

Waits until the socket has completed the SSL handshake and has emitted encrypted(), or msecs milliseconds, whichever comes first. If encrypted() has been emitted, this function returns true; otherwise (e.g., the socket is disconnected, or the SSL handshake fails), false is returned.

The following example waits up to one second for the socket to be encrypted:

socket->connectToHostEncrypted("imap", 993);
if (socket->waitForEncrypted(1000))
    qDebug("Encrypted!");

If msecs is -1, this function will not time out.

See also startClientEncryption(), startServerEncryption(), encrypted(), and isEncrypted().

[override virtual] bool QSslSocket::waitForReadyRead(int msecs = 30000)

Reimplemented from QAbstractSocket::waitForReadyRead().

[override virtual protected] qint64 QSslSocket::writeData(const char *data, qint64 len)

Reimplemented from QAbstractSocket::writeData().