<?php
/**
 * FH-Complete
 *
 * @package	FHC-Helper
 * @author	FHC-Team
 * @copyright	Copyright (c) 2016 fhcomplete.org
 * @license	GPLv3
 * @link	https://fhcomplete.org
 * @since	Version 1.0.0
 * @filesource
 */
if (! defined('BASEPATH'))
	exit('No direct script access allowed');

/**
 * FHC Helper
 *
 * @package		FH-Complete
 * @subpackage	Helpers
 * @category	Helpers
 * @author		FHC-Team
 * @link		http://fhcomplete.org/user_guide/helpers/fhcauth_helper.html
 */

// ------------------------------------------------------------------------


/**
 * generateToken() - generates a new token for diffent use
 * - reading Messages from external
 * - forgotten Password
 *
 * @return  string
 */
function generateToken($length = 64)
{
	// For PHP 7 you can use random_bytes()
	if(function_exists('random_bytes')) 
	{
		$token = base64_encode(random_bytes($length));
		//base64 is about 33% longer, so we need to truncate the result
		return strtr(substr($token, 0, $length), '+/=', '-_,');
	}

	// for PHP >=5.3 and <7
	if(function_exists('openssl_random_pseudo_bytes')) 
	{
        $token = base64_encode(openssl_random_pseudo_bytes($length, $strong));
		// is the token strong enough?
        if($strong == true)
			return strtr(substr($token, 0, $length), '+/=', '-_,');
    }

    //fallback to mt_rand if php < 5.3 or no openssl available
    $characters = '0123456789';
    $characters .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz/+'; 
    $charactersLength = strlen($characters)-1;
    $token = '';
    //select some random characters
    for ($i = 0; $i < $length; $i++)
        $token .= $characters[mt_rand(0, $charactersLength)];
    return $token;
}