HTTPS support on Pico!

I just put in a pull request for the feature that reads from the file system. PEM files can be stored in the default format and the certificate/key data will be parsed, removing beginning, ending delimiters and newline characters.

Here's example code using the file paths instead of cert strings:

var eth;
var connection;

var options = url.parse("mqtt://A1123456789AA.iot.us-east-1.amazonaws.com:8883");
options.ca = 'certs/rootCA.pem';
options.cert = 'certs/cert.pem';
options.key = 'certs/key.pem';

var mqtt = require("MQTT").create();
mqtt.on("connected", function() {
  console.log("connected to AWS IoT Service...");
  mqtt.subscribe("test/topic");
});

mqtt.on("publish", function (pub) {
  console.log("\nNew message received: ");
  console.log("topic: "+pub.topic);
  console.log("message: "+pub.message);
});

function onInit() {

  SPI2.setup({mosi:B15,miso:B14,sck:B13,baud:1000000});
  E.connectSDCard(SPI2,B1);
  
  SPI3.setup({ mosi:B5, miso:B4, sck:B3 });
  eth = require("WIZnet").connect(SPI3, A0);
  eth.setIP();
  
  require("tls").connect(options, function(res) {
    connection = res;
    console.log("tls connected");
    setTimeout(function() {
      mqtt.connect(res);
    },2000);
  });
}

The timeout is necessary to allow the certificate exchange and verification to complete before calling mqtt.connect. Maybe this can be event driven.