gpio-webhook-arduino/wifi.h

#include "config.h"
#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClientSecureBearSSL.h>

HTTPClient client;
BearSSL::WiFiClientSecure *secure_transport;
BearSSL::Session *tls_session;
BearSSL::X509List cert_list;

void syncTime() {
  // sync time
  Serial.print("Syncing time");
  configTime(8 * 3600, 0, "pool.ntp.org", "time.nist.gov");
  time_t now = time(nullptr);
  while (now < 8 * 3600 * 2) {
    delay(500);
    Serial.print(".");
    now = time(nullptr);
  }
  Serial.println("");
}

void initTLS() {
  secure_transport = new BearSSL::WiFiClientSecure();

  syncTime();
  cert_list.append(ca_cert);
  secure_transport->setTrustAnchors(&cert_list);

  tls_session = new BearSSL::Session();
  secure_transport->setSession(tls_session);
}

void InitWifi() {
  Serial.println("Attempting to connect to wifi");
  WiFi.disconnect();
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  int elapsed = 0;
  while (WiFi.status() != WL_CONNECTED) {
      Serial.print("Wifi connecting for ");
      Serial.print(elapsed);
      Serial.println(" seconds");
      elapsed++;
      delay(1000);
  }

  Serial.println("Wifi connected");
  
  initTLS();
}

String FetchURL(const char *path) {
  client.begin(*secure_transport, WEBHOOK_URL);

  int status = client.GET();
  if (status < 0) {
    Serial.print("Client error communicating with server: ");
    Serial.println(status);
    return "";
  }
  if (status >= 400) {
    Serial.print("Received HTTP status code ");
    Serial.println(status);
    return "";
  }

  return client.getString();
}