Moving to OpenSSL 3 in binary builds starting from Qt 6.5 Beta 2

This is a short but an important note for all those who use the binaries from the Qt builds provided in Qt Maintenance Tool as a runtime for applications in the field.

As some of you might know, Qt6 supports OpenSSL 3 since Qt 6.2.0. Starting from the next (second) beta of Qt 6.5, our binary builds will be based on OpenSSL 3. Since OpenSSL 3 is a new major version, it is not binary compatible with OpenSSL 1.x , see this link. This makes binary builds in Qt 6.5 beta 2 and later binary incompatible with applications using OpenSSL 1.x. If your application is using OpenSSL, you would need to rebuild it on top of Qt 6.5 binary builds from the Qt Maintenance Tool in order to run it on top of Qt 6.5 binaries or use your own builds based on OpenSSL 1.x. This is especially important for Linux applications, since Windows and macOS have other API for secure communications in addition to OpenSSL.

With this, we just want to make you aware of this change ahead of the Qt 6.5.0 release which is planned for March 2023.