DNSSEC support for Windows
The problem is obtaining system DNS configuration for use in resolver code. The relevant function is NewExtResolver in framework/dns/dnssec.go.
According to https://stackoverflow.com/a/13417318 comments it can be read from registry (DhcpNameServer or NameServer for each interface). Need to figure out which value should be preferred if there are multiple interfaces (or just use them all?).
I did some reason and it seems like Windows's DNS API does not expose information about DNSSEC status even for Windows versions that have the security-aware client implementation.
Therefore extracting DNS configuration from registry and querying servers directly seems to be the only way to obtain security information necessary for maddy security policies.