1 files changed, 41 insertions, 8 deletions
diff --git a/phpBB/phpbb/passwords/driver/helper.php b/phpBB/phpbb/passwords/driver/helper.php
index 4b8dc9a123..f80c3e3df6 100644
--- a/phpBB/phpbb/passwords/driver/helper.php
+++ b/phpBB/phpbb/passwords/driver/helper.php
@@ -1,21 +1,22 @@
 <?php
 /**
 *
-* @package phpBB3
-* @copyright (c) 2013 phpBB Group
-* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+* 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;
 
-/**
-* @package passwords
-*/
 class helper
 {
 	/**
-	* @var phpbb\config\config
+	* @var \phpbb\config\config
 	*/
 	protected $config;
 
@@ -28,7 +29,7 @@ class helper
 	/**
 	* Construct a driver helper object
 	*
-	* @param phpbb\config\config $config phpBB configuration
+	* @param \phpbb\config\config $config phpBB configuration
 	*/
 	public function __construct(\phpbb\config\config $config)
 	{
@@ -141,4 +142,36 @@ class helper
 		}
 		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;
+	}
 }