Support DTLS and coaps

[JKRhb]

Right now the module is missing DTLS support that is needed to use coaps. We should look into how to add support for this.

[invaderb]

Do you have any ideas on how to Implement DTLS?

There was a really long thread in the main node js repo about adding DTLS to core
nodejs/node#2398

From the thread having it in core would be best but there hasn't been any headway since 2015 on this so it seams either rolling our own or implementing an already created module possibly something like:
https://github.com/krekeltronics/node-mbed-dtls

[JKRhb]

https://github.com/krekeltronics/node-mbed-dtls looks promising :) Maybe we could also use something like https://github.com/AlCalzone/node-dtls-client for the short term (although it only support DTLS on the client side). I also saw this module in the issue you've linked: https://github.com/nodertc/dtls.

Having DTLS in core would be, of course, the best solution and very awesome. In theory, OpenSSL, which seems to be used by node-core, should already be able to support this: https://github.com/nodejs/node/search?q=dtls Maybe this could be utilized to provide "native" DTLS support some day.

[JKRhb]

Another library I just discovered is this one: https://www.npmjs.com/package/openssl-dtls It uses the DTLS capabilities already integrated in Node via OpenSSL