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/*!
    \page ssl.html
    \title Secure Sockets Layer (SSL) Classes
    \brief Classes for secure communication over network sockets.

    \keyword SSL

    The classes below provide support for secure network communication using
    the Secure Sockets Layer (SSL) protocol, using the \l{OpenSSL Toolkit}
    to perform encryption and protocol handling.

    From Qt version 5.6 onwards, the officially supported version for OpenSSL
    is 1.0.0 or later.

    \annotatedlist ssl


    \section1 Enabling and Disabling SSL Support

    When building Qt from source, the configuration system checks for the presence
    of the \c{openssl/opensslv.h} header provided by source or developer packages
    of OpenSSL.

    By default, an SSL-enabled Qt library dynamically loads any installed OpenSSL
    library at run-time. However, it is possible to link against the library at
    compile-time by configuring Qt with the \c{-openssl-linked} option.

    When building a version of Qt linked against OpenSSL, the build system will
    attempt to link with libssl and libcrypt libraries located in the default
    location on the developer's system. This location is configurable:
    set the \c OPENSSL_LIBS environment variable to contain the linker options
    required to link Qt against the installed library. For example, on a Unix/Linux
    system:

    \code
        OPENSSL_LIBS='-L/opt/ssl/lib -lssl -lcrypto' ./configure -openssl-linked
    \endcode

    To disable SSL support in a Qt build, configure Qt with the \c{-no-openssl}
    option.

    \section1 Datagram Transport Layer Security

    Datagram Transport Layer Security (DTLS) is a protocol that enables security
    for datagram-based applications, providing them with protection against
    eavesdropping, tampering, or message forgery. The DTLS protocol is based on the
    stream-oriented Transport Layer Security (TLS) protocol. QtNetwork enables
    the use of DTLS with User Datagram Protocol (UDP), as defined by
    \l {https://tools.ietf.org/html/rfc6347}{RFC 6347}.

    \section1 Import and Export Restrictions

    Qt binary installers include the OpenSSL libraries used by QtNetwork. However,
    those are not automatically deployed with applications that are built with Qt.
    Import and export restrictions apply for some types of software, and for
    some parts of the world. Developers wishing to use SSL communication in their
    deployed applications should either ensure that their users have the appropriate
    libraries installed, or they should consult a suitably qualified legal
    professional to ensure that applications using code from the OpenSSL project
    are correctly certified for import and export in relevant regions of the world.
*/