[Pkg-openssl-devel] OpenSSL+Qt interoperability?

[Antti J=?iso-8859-1?B?5A==?=rvinen]

Dear OpenSSL+Qt Sirs, 

I'm posting to both mailing lists at once because I don't know where
to start. I have a Qt app (classified-ads) that uses QSslSocket that 
internally uses OpenSSL for its work. This is a p2p-app where program
instances communicate with each others. I have an up-to-date debian
buster where this app was still working on Sunday 9th september. On
10th apt upgraded libqt5network5:amd64 from 5.11.1+dfsg-6 to 5.11.1+dfsg-7
and after that my attempts with QSslSocket receive
QAbstractSocket::SslInternalError, after that
QAbstractSocket::SslInvalidUserDataError and then socket is
closed. "User data error" according to documentation is "Invalid data
(certificate, key, cypher, etc.) was provided and its use resulted in
an error in the SSL library." but I need advice how to debug this
problem -> is there (easy) way to turn on logging of openssl while
it is being run inside qt app? 

For me the non-functional combination is 1.1.0h-4 and I've not touched
the configuration in /etc/ssl or 5.11.1+dfsg-7 that is also "out of
the box". Other nodes in this p2p network that have different versions
of qt and openssl seem to function all right - is this a working
combination that should work? The nodes in the network generally
handshake with TLS1.2, RSA2048+AES256, it should not be issue with
obsolete algorithm at least?

--
Antti Järvinen, desperately maintaining