Bug 2226054

dnssec-trigger checks whether servers provided by the network allow DNSSEC validation enabled on them. If the tests results in a server not supporting DNSSEC (it is not security-aware), it tries to configure alternative servers used for resolution. Those alternative servers were provided by unbound running on 3 fedora servers, but they were not maintained enough.

Because it turned out some features were not provided functional for some time, it were decided to shutdown them. Most networks today should be already prepared for validating end clients.

In case they are not, there are quite many open public resolvers offering encrypted or unencrypted resolution, which should work better for majority of users.

A good list of resolvers is at:
https://dnsprivacy.org/public_resolvers/



Reproducible: Always

Steps to Reproduce:
1. systemctl restart dnssec-triggerd
2. dnssec-trigger-control test_tcp
3. dnssec-trigger-control test_ssl
Actual Results:  
Resolution breaks, it does not work anymore. It can be fixed by systemctl restart dnssec-triggerd.

Expected Results:  
Resolution should be redirected to working server, which still provides connectivity to public resolvers.

All needed is update of /etc/dnssec-trigger/dnssec-trigger.conf. There comment out previous uncommented lines starting with tcp80: or ssl443: and instead insert upstream provided server:

# provided by NLnetLabs
# It is provided on a best effort basis, with no service guarantee.
tcp80: 185.49.140.67
tcp80: 2a04:b900::10:0:0:67
ssl443: 185.49.140.67 7E:CF:B4:BE:B9:9A:56:0D:F7:3B:40:51:A4:78:E6:A6:FD:66:0F:10:58:DC:A8:2E:C0:43:D4:77:5A:71:8A:CF
ssl443: 2a04:b900::10:0:0:67 7E:CF:B4:BE:B9:9A:56:0D:F7:3B:40:51:A4:78:E6:A6:FD:66:0F:10:58:DC:A8:2E:C0:43:D4:77:5A:71:8A:CF

I think we want to add simple way to support DNS over TLS servers in a modern way. That is without those weird hashes, but instead validating a name of a server and CA chain of its certificate. Just like for normal TLS services, for example in HTTPS. A separate bug #2223972 is filled for that.