How to use setCACert() of WiFiClientSecure with HTTPClient library? - esp8266

Question

I'd like to set my CA root cert (currently available via WiFiClientSecure library) and use convenient HTTPClient library for making request.
How to do that? In the example there is only showed how to use WiFiClientSecure with manually written request.

Answer 1

It's way to late but this post is one one of the ones that gets returned by google so it's a good way to help others like me who are just starting out with this.
It turns out that all the posts about WifiClientSecure are obsolete (or simply unnecessary).
Here's a working example using the default HTTPClient. (not HttpClient)
It does require setting the certificate's sha1 fingerprint in the begin statement.
void loop() {
// wait for WiFi connection
if ((WiFiMulti.run() == WL_CONNECTED)) {
HTTPClient http;
Serial.print("[HTTPS] begin...\n");
http.begin("https://some.secure_server.com/auth/authorise", "2F 2A BB 23 6B 03 89 76 E6 4C B8 36 E4 A6 BF 84 3D DA D3 9F");
http.addHeader("Content-Type", "application/x-www-form-urlencoded");
int httpCode = http.POST("user_id=mylogin&user_password=this%20is%20my%20%24ecret%20pa%24%24word");
if (httpCode > 0) {
http.writeToStream(&Serial);
// HTTP header has been send and Server response header has been handled
Serial.printf("[HTTP] ... code: %d\n", httpCode);
// file found at server
if (httpCode == HTTP_CODE_OK) {
String payload = http.getString();
Serial.println(payload);
}
} else {
Serial.printf("[HTTP] ... failed, error: %s\n", http.errorToString(httpCode).c_str());
}
http.end();
}
delay(10000);
}