exampleAPiCall.php

<?php
/**
 * Example class demonstrating how to create the authorization headers for accessing the Publisher API.
 *
 * Class APIAccessExample
 */

class APIAccessExample
{
    private $apiEndpoint;
    const PARAM_TOKEN = 'Authorization';
    const PARAM_DATE = 'AuthDate';

        /**
         * @param $privateKey
         * @param $publicKey
         * @param $endpoint
         */
    public function __construct($privateKey, $publicKey, $endpoint)
    {
        $this->privateKey = $privateKey;
        $this->publicKey = $publicKey;
        $this->apiEndpoint = $endpoint;
    }


    /**
     * @param DateTime $date
     * @return array
     */
    private function createAuthHeader(\DateTime $date)
     {
         $encodedAuthString = base64_encode(hash_hmac('sha1', $date->format(\DateTime::ISO8601), $this->privateKey, true));
         $headers = array(
             'Content-length: 0',
             'Accept: application/json',
             'Authorization: ' . sprintf('%s:%s', $this->publicKey, $encodedAuthString),
             'AuthDate: ' . utf8_encode($date->format(\DateTime::ISO8601)),
         );

         return $headers;
     }

        /**
         * Makes a call to the API on the path provide using the headers
         *
         * @param $path
         * @return mixed
         */
    public function call($path)
    {
        $date = new \DateTime();

        $url = sprintf('%s/%s', $this->apiEndpoint, $path);
        $curl = curl_init($url);
        curl_setopt($curl, CURLOPT_HEADER, false);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl,  CURLOPT_POST, true);
        curl_setopt($curl, CURLOPT_VERBOSE, true);
        curl_setopt($curl, CURLOPT_HTTPHEADER, $this->createAuthHeader($date));

        $jsonResponse = curl_exec($curl);

        curl_close($curl);

        return $jsonResponse;
    }

}


//Example usage


// keypair will be provided
$privateKey = "privatekey";
$publicKey = "publickey";


// endpoint
$endpoint = 'http://api-url';
$api = new APIAccessExample($privateKey, $publicKey, $endpoint);
$json = $api->call('createUserSubscription');
echo $json;