How to include Authorization header in cURL POST HTTP Request in PHP?

@jason-mccreary is totally right. Besides I recommend you this code to get more info in case of malfunction:

$rest = curl_exec($crl);

if ($rest === false)
{
    // throw new Exception('Curl error: ' . curl_error($crl));
    print_r('Curl error: ' . curl_error($crl));
}

curl_close($crl);
print_r($rest);

EDIT 1

To debug you can set CURLOPT_HEADER to true to check HTTP response with firebug::net or similar.

curl_setopt($crl, CURLOPT_HEADER, true);

EDIT 2

About Curl error: SSL certificate problem, verify that the CA cert is OK try adding this headers (just to debug, in a production enviroment you should keep these options in true):

curl_setopt($crl, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($crl, CURLOPT_SSL_VERIFYPEER, false);

You have most of the code…

CURLOPT_HTTPHEADER for curl_setopt() takes an array with each header as an element. You have one element with multiple headers.

You also need to add the Authorization header to your $header array.

$header = array();
$header[] = 'Content-length: 0';
$header[] = 'Content-type: application/json';
$header[] = 'Authorization: OAuth SomeHugeOAuthaccess_tokenThatIReceivedAsAString';