Otherwise individual sockets will still load system certificates when
a chain doesn't match against the configured CA certificates.
That's not intended behavior, since specifically setting the CA
certificates means you don't want the system certificates to be used.
Follow-up to/amends ada2c573c1
This is potentially a breaking change because now, if you ever add a
CA to the default config, it will disable loading system certificates
on demand for all sockets. And the only way to re-enable it is to
create a null-QSslConfiguration and set it as the new default.
Pick-to: 6.5 6.2 5.15
Change-Id: Ic3b2ab125c0cdd58ad654af1cb36173960ce2d1e
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
Not entirely clear why, but when building the certificate chain for a
peer the system certificate store is searched for root certificates.
General expectation is that after calling
`sslConfiguration.setCaCertificates()` the system certificates will
not be taken into consideration.
To work around this behavior, we do a manual check that the root of the
chain is part of the configured CA certificates.
Pick-to: 6.5 6.2 5.15
Change-Id: I03666a4d9b0eac39ae97e150b4743120611a11b3
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
