[feature/passwords] Add driver helper class file

PHPBB3-11610

phpBB/includes/crypto/driver/helper.php

@@ -0,0 +1,108 @@
+<?php
+/**
+*
+* @package phpBB3
+* @copyright (c) 2013 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* @package crypto
+*/
+class phpbb_crypto_driver_helper
+{
+	/** @var phpbb_config */
+	protected $driver;
+
+	/**
+	* Constructor of crypto driver helper object
+	*/
+	public function __construct($driver)
+	{
+		$this->driver = $driver;
+	}
+
+	/**
+	* Base64 encode hash
+	*
+	* @param string $input Input string
+	* @param int $count Input string length
+	* @param string $itoa64 Allowed characters string
+	*
+	* @return string base64 encoded string
+	*/
+	public function hash_encode64($input, $count, &$itoa64)
+	{
+		$output = '';
+		$i = 0;
+
+		do
+		{
+			$value = ord($input[$i++]);
+			$output .= $itoa64[$value & 0x3f];
+
+			if ($i < $count)
+			{
+				$value |= ord($input[$i]) << 8;
+			}
+
+			$output .= $itoa64[($value >> 6) & 0x3f];
+
+			if ($i++ >= $count)
+			{
+				break;
+			}
+
+			if ($i < $count)
+			{
+				$value |= ord($input[$i]) << 16;
+			}
+
+			$output .= $itoa64[($value >> 12) & 0x3f];
+
+			if ($i++ >= $count)
+			{
+				break;
+			}
+
+			$output .= $itoa64[($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;
+		global $config;
+
+		$val = $config['rand_seed'] . microtime();
+		$val = md5($val);
+		$config['rand_seed'] = md5($config['rand_seed'] . $val . $extra);
+
+		if ($dss_seeded !== true && ($config['rand_seed_last_update'] < time() - rand(1,10)))
+		{
+			set_config('rand_seed_last_update', time(), true);
+			set_config('rand_seed', $config['rand_seed'], true);
+			$dss_seeded = true;
+		}
+
+		return substr($val, 4, 16);
+	}
+}