init.php

<?php
/**
 * Copyright MITRE 2015
 *
 * AuthOpenIDConnect for PHP5
 * Author: Michael Jett <mjett@mitre.org>
 * Author: Oded Arbel <oded@geek.co.il>
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License. You may obtain
 * a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

/**
 *
 * JWT signature verification support by Jonathan Reed <jdreed@mit.edu>
 * Licensed under the same license as the rest of this file.
 *
 * phpseclib is required to validate the signatures of some tokens.
 * It can be downloaded from: http://phpseclib.sourceforge.net/
 */
if (!class_exists('\\phpseclib\\Crypt\\RSA')) {
    user_error('Unable to find \\phpseclib\\Crypt\\RSA.php.  Ensure phpseclib is installed and in include_path');
}

/**
 * A wrapper around base64_decode which decodes Base64URL-encoded data,
 * which is not the same alphabet as base64.
 */
function base64url_decode($base64url) {
    return base64_decode(b64url2b64($base64url));
}

/**
 * Per RFC4648, "base64 encoding with URL-safe and filename-safe
 * alphabet".  This just replaces characters 62 and 63.  None of the
 * reference implementations seem to restore the padding if necessary,
 * but we'll do it anyway.
 *
 */
function b64url2b64($base64url) {
    // "Shouldn't" be necessary, but why not
    $padding = strlen($base64url) % 4;
    if ($padding > 0) {
	$base64url .= str_repeat("=", 4 - $padding);
    }
    return strtr($base64url, '-_', '+/');
}

/**
 * Require the CURL and JSON PHP extentions to be installed
 */
if (!function_exists('curl_init')) {
    throw new OpenIDConnectClientException('OpenIDConnect needs the CURL PHP extension.');
}
if (!function_exists('json_decode')) {
    throw new OpenIDConnectClientException('OpenIDConnect needs the JSON PHP extension.');
}

require_once(__DIR__ . '/classes/OpenIDConnectClientException.php');
require_once(__DIR__ . '/classes/OpenIDSessionStorageIF.php');
require_once(__DIR__ . '/classes/OpenIDSessionStorageDefault.php');
require_once(__DIR__ . '/classes/OpenIDConnectClient.php');