<?php
/**
*
* This file is part of the phpBB Forum Software package.
*
* @copyright (c) phpBB Limited <https://www.phpbb.com>
* @license GNU General Public License, version 2 (GPL-2.0)
*
* For full copyright and license information, please see
* the docs/CREDITS.txt file.
*
*/
namespace phpbb\passwords\driver;
class helper
{
/**
* @var \phpbb\config\config
*/
protected $config;
/**
* base64 alphabet
* @var string
*/
public $itoa64 = './0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
/**
* Construct a driver helper object
*
* @param \phpbb\config\config $config phpBB configuration
*/
public function __construct(\phpbb\config\config $config)
{
$this->config = $config;
}
/**
* Base64 encode hash
*
* @param string $input Input string
* @param int $count Input string length
*
* @return string base64 encoded string
*/
public function hash_encode64($input, $count)
{
$output = '';
$i = 0;
do
{
$value = ord($input[$i++]);
$output .= $this->itoa64[$value & 0x3f];
if ($i < $count)
{
$value |= ord($input[$i]) << 8;
}
$output .= $this->itoa64[($value >> 6) & 0x3f];
if ($i++ >= $count)
{
break;
}
if ($i < $count)
{
$value |= ord($input[$i]) << 16;
}
$output .= $this->itoa64[($value >> 12) & 0x3f];
if ($i++ >= $count)
{
break;
}
$output .= $this->itoa64[($value >> 18) & 0x3f];
}
while ($i < $count);
return $output;
}
/**
* Return unique id
*
* @param string $extra Additional entropy
*
* @return string Unique id
*/
public function unique_id($extra = 'c')
{
static $dss_seeded = false;
$val = $this->config['rand_seed'] . microtime();
$val = md5($val);
$this->config['rand_seed'] = md5($this->config['rand_seed'] . $val . $extra);
if ($dss_seeded !== true && ($this->config['rand_seed_last_update'] < time() - rand(1,10)))
{
$this->config->set('rand_seed_last_update', time(), true);
$this->config->set('rand_seed', $this->config['rand_seed'], true);
$dss_seeded = true;
}
return substr($val, 4, 16);
}
/**
* Get random salt with specified length
*
* @param int $length Salt length
* @param string $rand_seed Seed for random data (optional). For tests.
*
* @return string Random salt with specified length
*/
public function get_random_salt($length, $rand_seed = '/dev/urandom')
{
$random = '';
if (($fh = @fopen($rand_seed, 'rb')))
{
$random = fread($fh, $length);
fclose($fh);
}
if (strlen($random) < $length)
{
$random = '';
$random_state = $this->unique_id();
for ($i = 0; $i < $length; $i += 16)
{
$random_state = md5($this->unique_id() . $random_state);
$random .= pack('H*', md5($random_state));
}
$random = substr($random, 0, $length);
}
return $random;
}
/**
* Compare two strings byte by byte
*
* @param string $string_a The first string
* @param string $string_b The second string
*
* @return bool True if strings are the same, false if not
*/
public function string_compare($string_a, $string_b)
{
// Return if input variables are not strings or if length does not match
if (!is_string($string_a) || !is_string($string_b) || strlen($string_a) != strlen($string_b))
{
return false;
}
// Use hash_equals() if it's available
if (function_exists('hash_equals'))
{
return hash_equals($string_a, $string_b);
}
$difference = 0;
for ($i = 0; $i < strlen($string_a) && $i < strlen($string_b); $i++)
{
$difference |= ord($string_a[$i]) ^ ord($string_b[$i]);
}
return $difference === 0;
}
}