Proof-of-concept server (in node.js) and clients (in node.js and Android) demonstrating an API communicating over the DNS protocol. See the writeup on Medium.
This proof-of-concept server does a String-toUpperCase translation, but it could be expanded to any server that pairs a short (around 100 byte) request to a short (around 256 byte) response.
You'll need a server with a dedicated IP address, and a domain name whose DNS records you can configure. Configure one "A" DNS record to associate a name with your server's IP address, and one "NS" DNS record that points to the first:
| subdomain | record type | data |
|---|---|---|
| a.mydomain.com | A Record | 1.2.3.4 |
| b.mydomain.com | NS Record | a.mydomain.com |
Configure your host in config.json (note the preceeding dot):
cd location-of-this-cloned-repo
echo '{ "host_suffix": ".b.mydomain.com" }' > config.json
Install server-js/dns-server.js on your server, install and run it:
cd server-js
install
node dns-server.js
That's it!
You may need to wait a bit for your DNS configuration to propogate. After that, you can test it from the command line:
dig -t txt hello-world.b.mydomain.com +short
-or-
host -t TXT hello-world.b.mydomain.com
Once it works there, try the client-js/dns-client.js from your local box:
cd location-of-this-cloned-repo
echo '{ "host_suffix": ".b.mydomain.com" }' > config.json
cd client-js
install
node dns-client.js hello-world
If that works too, you're ready to import the Android app into Android Studio. It'll happily use the same config.json that you already configured earlier.
You're done! Time to try something more interesting than .toUpperCase(). Modify the process(query) function in dns-server.js.