Using the OpenSSL Dependency for GDS Support

The GDS feature of Qt OPC UA requires the OpenSSL 1.1 headers and libraries.

If OpenSSL is not installed to a path that is searched by default, the location of the headers and libraries must be passed to the build process.

For example, if OpenSSL 1.1 has been installed to /opt/openssl, the locations must be passed as follows:

 -DOPENSSL_ROOT_DIR=/opt/openssl/

If GDS support is not required, it can be disabled by using the following parameters:

 -DFEATURE_gds=OFF

In this case, OpenSSL is not required.