Using dynaname it is already possible to securely auto-update DNS records in a bind9, but this still needs a linux machine. This project is about building a CGI frontend for it that makes it a replacement for the discontinued dyndns.org service.
my CGI is now in <a href="https://github.com/bmwiedemann/dynaname">github</a>
It has the advantage of not needing any database and working stateless, meaning you can run the same CGI on 5 hosts behind HAProxy and it does not need to run on the DNS-server host, just reach its port 53
example CGI call: https://aw.zq1.de/cgi-bin/public/dyndnsupdate?hostname=test.d.zq1.de&myip=188.8.131.52&dnsserver=vm2b.zq1.de&key=test.d.zq1.de.+IN+KEY+0+3+165+lbHxnch9j6iFScnQzc3r9ta9PRslOsOaoGdB%2FYgT0jxKHOkyynJOjPYo+2Oc%2Fyx7ShovatqOkPnrW%2BX0VVLFr5A%3D%3D%0D%0A
This project is one of its kind!