When the tests were added, the files were generated without FIPS
compatibility in mind. That made the tests fail on recent OpenSSL
versions in FIPS mode.
So, the files were regenerated on a FIPS compliant system using the
following stanza:
$ openssl dhparam -out <file> 3072
Apparently, the old files are not valid for FIPS starting with OpneSSL
3.1.X release series as "FIPS 140-3 compliance changes" are mentioned
in the changelog:
https://openssl-library.org/news/openssl-3.1-notes/
Change the 'forward' system test to enable DoT on ns2 server,
and test that forwarding from ns4 to the DoT-enabled ns2 works.
In order to test different scenarios, create a test CA (based on
similar CAs for 'doth' and 'nsupdate' system tests), and test
both insecure (no certificate validation) and secure (also with
mutual TLS) TLS configurations, as well as a configuration with an
expired certificate.
