QSslConfiguration

QSslConfiguration is a class in the Qt Network module that describes the SSL/TLS settings used for secure network connections, such as those performed by QSslSocket and related networking components. It provides a programmatic way to specify how TLS is negotiated, including the protocol version, the cipher suites that may be used, and the credentials and trust anchors involved in the handshake. Applications can obtain the current configuration, modify its properties, and apply it to a socket or network component to control TLS behavior.

Key elements stored by QSslConfiguration include the SSL protocol version, the list of allowed ciphers, the peer verification mode (whether the peer’s certificate should be verified or not), and the verification depth. It also holds the local credentials presented to the peer, such as a local certificate and its private key, and the set of trusted CA certificates used to validate the peer’s certificate. The configuration can also influence how certificates are validated and which certificates are considered trustworthy.

QSslConfiguration can be retrieved, modified, and then applied to individual sockets or network access components. There is typically a notion of a default configuration that can be changed globally, while sockets may also possess their own explicit configurations. This allows both global uniform security policies and per-connection customization.

In practice, QSslConfiguration is used to enforce secure connections by selecting appropriate TLS versions, enabling or disabling peer verification as appropriate, and ensuring that proper certificates and CA authorities are in place. Care should be taken to keep CA certificates current and to avoid turning off verification in production environments. See also related classes such as QSslCertificate, QSslKey, and QSslSocket.