Hi there, great question!
In general I’d suggest looking at other (link1) similar (link2) solutions (link3) such as where an Arduino has been made to Tweet. Unfortunately yes, you do need to use SSL and OAuth with the Twitter API.
A pattern I’ve seen used in Internet of Things style solutions is to use a proxy of your own to provide access to the Twitter API - for instance, using a lightweight protocol like MQTT from the device, to post to a service like Node-RED which handles the HTTP communication with Twitter’s API.
It certainly is possible to do the OAuth piece on a smaller device as the Twitter library for Arduino proves, but you may be limited by memory etc.
