QKnxNetIpSessionAuthenticateProxy Class

The QKnxNetIpSessionAuthenticateProxy class provides the means to introspect session authentication data inside the generic QKnxNetIpFrame class and to create a KNXnet/IP session authentication frame from provided data. More...

Header: #include <QKnxNetIpSessionAuthenticateProxy>
qmake: QT += knx
Since: Qt 5.12

This class was introduced in Qt 5.12.

Public Types

class Builder
class SecureBuilder

Public Functions

QKnxNetIpSessionAuthenticateProxy(const QKnxNetIpFrame &frame)
bool isValid() const
QKnxByteArray messageAuthenticationCode() const
QKnxNetIp::SecureUserId userId() const

Static Public Members

QKnxNetIpSessionAuthenticateProxy::Builder builder()
QKnxNetIpSessionAuthenticateProxy::SecureBuilder secureBuilder()

Detailed Description

This class is part of the Qt KNX module and currently available as a Technology Preview, and therefore the API and functionality provided by the class may be subject to change at any time without prior notice.

This frame will be sent by the KNXnet/IP secure client to the control endpoint of the KNXnet/IP secure server after the Diffie-Hellman handshake to authenticate the user against the server device. The maximum time a KNXnet/IP secure client will wait for an authentication status response of the KNXnet/IP secure server is 10 seconds.

Note: When using QKnxNetIpSessionAuthenticateProxy, care must be taken to ensure that the referenced KNXnet/IP frame outlives the proxy on all code paths, lest the proxy ends up referencing deleted data.

The following code sample illustrates how to read the session authentication information:

auto netIpFrame = QKnxNetIpFrame::fromBytes(...);

const QKnxNetIpSessionAuthenticateProxy proxy(netIpFrame);
if (!proxy.isValid())

auto id = proxy.userId();
auto authenticatenCode = proxy.messageAuthenticationCode();

See also builder() and Qt KNXnet/IP Connection Classes.

Member Function Documentation

QKnxNetIpSessionAuthenticateProxy::QKnxNetIpSessionAuthenticateProxy(const QKnxNetIpFrame &frame)

Constructs a proxy object to read the session authentication information carried by the specified KNXnet/IP frame frame.

[static] QKnxNetIpSessionAuthenticateProxy::Builder QKnxNetIpSessionAuthenticateProxy::builder()

Returns a builder object to create a KNXnet/IP session authentication frame.

bool QKnxNetIpSessionAuthenticateProxy::isValid() const

Returns true if the frame contains initialized values and is in itself valid, otherwise returns false. A valid KNXnet/IP frame consists of at least a valid header and a size in bytes corresponding to the total size of the KNXnet/IP frame header.

Note: A userId() with the value QKnxNetIp::SecureUserId::Reserved or equal to or more than QKnxNetIp::SecureUserId::Invalid is considered invalid according to the KNX application note AN159.

Note: KNXnet/IP session authentication frames currently have a fixed size of 24 bytes.

See also QKnxNetIpFrameHeader::totalSize().

QKnxByteArray QKnxNetIpSessionAuthenticateProxy::messageAuthenticationCode() const

Returns the AES128 CCM message authentication code (MAC) from the generic KNXnet/IP session authentication frame with a fixed size of 16 bytes.

[static] QKnxNetIpSessionAuthenticateProxy::SecureBuilder QKnxNetIpSessionAuthenticateProxy::secureBuilder()

Returns a builder object to create a KNXnet/IP session authentication frame.

QKnxNetIp::SecureUserId QKnxNetIpSessionAuthenticateProxy::userId() const

Returns the user ID from the generic KNXnet/IP session authentication frame.

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