--- /dev/null
+<?php
+
+/**
+ * This file contains an example helper classes for the php-scrypt extension.
+ *
+ * As with all cryptographic code; it is recommended that you use a tried and
+ * tested library which uses this library; rather than rolling your own.
+ *
+ * PHP version 5
+ *
+ * @category Security
+ * @package Scrypt
+ * @author Dominic Black <thephenix@gmail.com>
+ * @license http://www.opensource.org/licenses/BSD-2-Clause BSD 2-Clause License
+ * @link http://github.com/DomBlack/php-scrypt
+ */
+
+/**
+ * This class abstracts away from scrypt module, allowing for easy use.
+ *
+ * You can create a new hash for a password by calling Password::hash($password)
+ *
+ * You can check a password by calling Password::check($password, $hash)
+ *
+ * @category Security
+ * @package Scrypt
+ * @author Dominic Black <thephenix@gmail.com>
+ * @license http://www.opensource.org/licenses/BSD-2-Clause BSD 2-Clause License
+ * @link http://github.com/DomBlack/php-scrypt
+ */
+class Scrypt
+{
+
+ /**
+ *
+ * @var int The key length
+ */
+ private static $_keyLength = 32;
+
+ /**
+ * Get the byte-length of the given string
+ *
+ * @param string $str Input string
+ *
+ * @return int
+ */
+ protected static function strlen( $str ) {
+ static $isShadowed = null;
+
+ if ($isShadowed === null) {
+ $isShadowed = extension_loaded('mbstring') &&
+ ini_get('mbstring.func_overload') & 2;
+ }
+
+ if ($isShadowed) {
+ return mb_strlen($str, '8bit');
+ } else {
+ return strlen($str);
+ }
+ }
+
+ /**
+ * Generates a random salt
+ *
+ * @param int $length The length of the salt
+ *
+ * @return string The salt
+ */
+ public static function generateSalt($length = 8)
+ {
+ $buffer = '';
+ $buffer_valid = false;
+ if (function_exists('random_bytes')) {
+ try {
+ $buffer = random_bytes($length);
+ $buffer_valid = true;
+ } catch (Exception $ignored) { }
+ }
+
+ if (!$buffer_valid && function_exists('mcrypt_create_iv') && !defined('PHALANGER')) {
+ $buffer = mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
+ if ($buffer) {
+ $buffer_valid = true;
+ }
+ }
+
+ if (!$buffer_valid && is_readable('/dev/urandom')) {
+ $f = fopen('/dev/urandom', 'r');
+ $read = static::strlen($buffer);
+ while ($read < $length) {
+ $buffer .= fread($f, $length - $read);
+ $read = static::strlen($buffer);
+ }
+ fclose($f);
+ if ($read >= $length) {
+ $buffer_valid = true;
+ }
+ }
+
+ if (!$buffer_valid) {
+ throw new Exception("No suitable random number generator available");
+ }
+
+ $salt = str_replace(array('+', '$'), array('.', ''), base64_encode($buffer));
+
+ return $salt;
+ }
+
+ /**
+ * Create a password hash
+ *
+ * @param string $password The clear text password
+ * @param string $salt The salt to use, or null to generate a random one
+ * @param int $N The CPU difficultly (must be a power of 2, > 1)
+ * @param int $r The memory difficultly
+ * @param int $p The parallel difficultly
+ *
+ * @return string The hashed password
+ */
+ public static function hash($password, $salt = false, $N = 16384, $r = 8, $p = 1)
+ {
+ if ($N == 0 || ($N & ($N - 1)) != 0) {
+ throw new \InvalidArgumentException("N must be > 0 and a power of 2");
+ }
+
+ if ($N > PHP_INT_MAX / 128 / $r) {
+ throw new \InvalidArgumentException("Parameter N is too large");
+ }
+
+ if ($r > PHP_INT_MAX / 128 / $p) {
+ throw new \InvalidArgumentException("Parameter r is too large");
+ }
+
+ if ($salt === false) {
+ $salt = self::generateSalt();
+ } else {
+ // Remove dollar signs from the salt, as we use that as a separator.
+ $salt = str_replace(array('+', '$'), array('.', ''), base64_encode($salt));
+ }
+
+ $hash = scrypt($password, $salt, $N, $r, $p, self::$_keyLength);
+
+ return $N . '$' . $r . '$' . $p . '$' . $salt . '$' . $hash;
+ }
+
+ /**
+ * Check a clear text password against a hash
+ *
+ * @param string $password The clear text password
+ * @param string $hash The hashed password
+ *
+ * @return boolean If the clear text matches
+ */
+ public static function check($password, $hash)
+ {
+ // Is there actually a hash?
+ if (!$hash) {
+ return false;
+ }
+
+ list ($N, $r, $p, $salt, $hash) = explode('$', $hash);
+
+ // No empty fields?
+ if (empty($N) or empty($r) or empty($p) or empty($salt) or empty($hash)) {
+ return false;
+ }
+
+ // Are numeric values numeric?
+ if (!is_numeric($N) or !is_numeric($r) or !is_numeric($p)) {
+ return false;
+ }
+
+ $calculated = scrypt($password, $salt, $N, $r, $p, self::$_keyLength);
+
+ // Use compareStrings to avoid timeing attacks
+ return self::compareStrings($hash, $calculated);
+ }
+
+ /**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @link http://github.com/zendframework/zf2 for the canonical source repository
+ * @copyright Copyright (c) 2005-2013 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license http://framework.zend.com/license/new-bsd New BSD License
+ *
+ * Compare two strings to avoid timing attacks
+ *
+ * C function memcmp() internally used by PHP, exits as soon as a difference
+ * is found in the two buffers. That makes possible of leaking
+ * timing information useful to an attacker attempting to iteratively guess
+ * the unknown string (e.g. password).
+ *
+ * @param string $expected
+ * @param string $actual
+ *
+ * @return boolean If the two strings match.
+ */
+ public static function compareStrings($expected, $actual)
+ {
+ $expected = (string) $expected;
+ $actual = (string) $actual;
+ $lenExpected = static::strlen($expected);
+ $lenActual = static::strlen($actual);
+ $len = min($lenExpected, $lenActual);
+
+ $result = 0;
+ for ($i = 0; $i < $len; $i ++) {
+ $result |= ord($expected[$i]) ^ ord($actual[$i]);
+ }
+ $result |= $lenExpected ^ $lenActual;
+
+ return ($result === 0);
+ }
+}
projects / core.git / blobdiff