Homebrew formula for validns, using a fork of DENIC eG with working OpenSSL 1.1 support:
https://github.com/DENICeG/validns
brew install fhemberger/validns/validns
Or brew tap fhemberger/validns
and then brew install validns
.
brew help
, man brew
or check Homebrew's documentation.