_config.php

<?php
/**
 * @file
 * A single location to store configuration.
 */

/**
 * Define for file includes. The certs directory is best stored out of web root so moving the directory
 * and updating the reference to BASE_PATH is the best way to ensure things keep working
 */
define('BASE_PATH',dirname(__FILE__));

/**
 * Define which app type you are using:
 * Private - private app method
 * Public - standard public app method
 * Partner - partner app method
 */
define("XRO_APP_TYPE",     "Partner");

/**
 * Set a user agent string that matches your application name as set in the Xero developer centre
 */
$useragent = "";

/**
 * Set your callback url or set 'oob' if none required
 */
define("OAUTH_CALLBACK",     'http://localhost/XeroOAuth-PHP/example.php');

/**
 * Application specific settings
 * Not all are required for given application types
 * consumer_key: required for all applications
 * consumer_secret:  for partner applications, set to: s (cannot be blank)
 * rsa_private_key: application certificate private key - not needed for public applications
 * rsa_public_key:  application certificate public cert - not needed for public applications
 */

$signatures = array(
    'consumer_key'     => 'MWSAN8S5AAFPMMNBV3DQIEWH4TM9FE',
    'shared_secret'    => 's',
    // API versions
    'core_version'=> '2.0',
    'payroll_version'=> '1.0',
);

if (XRO_APP_TYPE=="Private"||XRO_APP_TYPE=="Partner") {
    $signatures['rsa_private_key']= BASE_PATH . '/certs/privatekey.pem';
    $signatures['rsa_public_key']= BASE_PATH . '/certs/publickey.cer';
}


/**
 * Special options for Partner applications
 * Partner applications require a Client SSL certificate which is issued by Xero
 * the certificate is issued as a .p12 cert which you will then need to split into a cert and private key:
 * openssl pkcs12 -in entrust-client.p12 -clcerts -nokeys -out entrust-cert.pem
 * openssl pkcs12 -in entrust-client.p12 -nocerts -out entrust-private.pem <- you will be prompted to enter a password
 */
if (XRO_APP_TYPE=="Partner") {
    $signatures['curl_ssl_cert'] = BASE_PATH . '/certs/entrust-cert-RQ3.pem';
    $signatures['curl_ssl_password'] = '1234';
    $signatures['curl_ssl_key'] = BASE_PATH . '/certs/entrust-private-RQ3.pem';
}