PHP - Stripe Connect return null - php

Question

I'm starting with Stripe Payment and need to connect the user to my Stripe app. I follow the guildance in Stripe to get the accesss_token with the PHP code:
// See full code example here: https://gist.github.com/3507366
if (isset($_GET['code'])) { // Redirect w/ code
$code = $_GET['code'];
$token_request_body = array(
'grant_type' => 'authorization_code',
'client_id' => 'ca_*************************',
'code' => $code,
'client_secret' => 'sk_test_************************'
);
$req = curl_init(TOKEN_URI);
curl_setopt($req, CURLOPT_RETURNTRANSFER, true);
curl_setopt($req, CURLOPT_POST, true );
curl_setopt($req, CURLOPT_POSTFIELDS, http_build_query($token_request_body));
// TODO: Additional error handling
$respCode = curl_getinfo($req, CURLINFO_HTTP_CODE);
$resp = json_decode(curl_exec($req), true);
curl_close($req);
echo $resp['access_token'];
} else if (isset($_GET['error'])) { // Error
echo $_GET['error_description'];
} else { // Show OAuth link
$authorize_request_body = array(
'response_type' => 'code',
'scope' => 'read_write',
'client_id' => 'ca_************************'
);
$url = AUTHORIZE_URI . '?' . http_build_query($authorize_request_body);
echo "<a href='$url'>Connect with Stripe</a>";
}
But the response from Stripe is always null. Has anyone experienced the same problem like this before. Any help would be very valuable for me this time.
Thank you very much.

Answer 1

After a while of debugging, I found out the problem is with the cURL library of my PHP server. It seem cURL not work with HTTPS. And base on this thread: PHP cURL Not Working with HTTPS
I find the solution to make it run by bypassing the verification:
...
curl_setopt($req, CURLOPT_POSTFIELDS, http_build_query($token_request_body));
curl_setopt($req, CURLOPT_SSL_VERIFYPEER, false); // Bypass the verification
$resp = json_decode(curl_exec($req), true); // Now has response well.
...
P/s: This is not a good solution, better do more research (here)
I hope this help some beginner like me :)