Not able to get JSON response using CURL PHP

Question

I am trying to write a PHP script that post username and password as JSON object to a server and in response get a JSON object that contains UserId and token in JSON.

Following is my code

if (isset($_GET["user"]) && isset($_GET["key"])){

$username = $_GET["user"];
$pass = $_GET["key"];

$data = array("username" => $username, "password" => $pass);                                                                                   
$data_string = json_encode($data);              
echo $data_string;

$ch = curl_init('https://sce15.appspot.com/api/g_usrs/signin');                                                                                                                                           
curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);                                                                  
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);                                                                      
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));                                                                                                                   

$response = curl_exec($ch);

curl_close($ch);

$usr = json_decode($response, true);
echo $usr;

}
else{

    echo "Oops Something went wrong: Error 1";
}

But I am not getting anything in output, my browser window is white blank. I am not able to figure out the mistake. I am able to get JSON object when using javascript for the same URL, but I need to do it with PHP.

Any help is appreciated. Thanks

Answer 1

I finally pointed out the problem after 2 days of head banging on google. It was the SSL certificate error, CURL was not able to verify the SSL certificate.

I got to knew that after checking curl errors print_r(curl_error($ch));

And then by using the curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); i was able to disable SSL certificate security check. Although it made my connection insecure but i think that's not important in my case.

Thanks Everyone