cURL error 60: SSL certificate prblm: unable to get local issuer certificate

Question

I want to collect a list of videos uploaded on a specific channel using the YouTube data API. However, before implementing online I am trying to get my code running on an offline environment (WAMPserver, PHP 5.5.12, Apache 2.4.9). I am using the following code:

require_once 'google-api-php-client-2.0.0-RC5/vendor/autoload.php';

$client = new Google_Client();
$client->setApplicationName("SRC_Thor");
$client->setDeveloperKey("xxxxxxxxxxx");

$youtube = new Google_Service_YouTube($client);

$channelResponse = $youtube->channels->listChannels('contentDetails', []);
var_dump($channelResponse);

However it gives the following error:

Fatal error: Uncaught exception 'GuzzleHttp\Exception\RequestException' with message 'cURL error 60: SSL certificate problem: unable to get local issuer certificate (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)'

I have tried adding the latest version of cacert.pem as most topics on SO offer as a solution, however to no avail.

Answer 1

If you are on Windows using Xampp, I am stealing a better answer from here, would be helpful if Google shows you this question first.

1. Download and extract for cacert.pem here (a clean file format/data)

   https://curl.haxx.se/docs/caextract.html

2. Put it in :

   C:\xampp\php\extras\ssl\cacert.pem

3. Add this line to your php.ini

   curl.cainfo = "C:\xampp\php\extras\ssl\cacert.pem"

4. restart your webserver/Apache