gistfile1.aw

<?php

class Bcrypt
{
  const DEFAULT_WORK_FACTOR = 8;

  public static function hash($password, $work_factor = 0)
  {
    if (version_compare(PHP_VERSION, '5.3') < 0) throw new Exception('Bcrypt requires PHP 5.3 or above');

    if (! function_exists('openssl_random_pseudo_bytes')) {
      throw new Exception('Bcrypt requires openssl PHP extension');
    }

    if ($work_factor < 4 || $work_factor > 31) $work_factor = self::DEFAULT_WORK_FACTOR;
    $salt =
      '$2a$' . str_pad($work_factor, 2, '0', STR_PAD_LEFT) . '$' .
    substr(
      strtr(base64_encode(openssl_random_pseudo_bytes(16)), '+', '.'),
      0, 22
      )
      ;
    return crypt($password, $salt);
  }

  public static function check($password, $stored_hash, $legacy_handler = NULL)
  {
    if (version_compare(PHP_VERSION, '5.3') < 0) throw new Exception('Bcrypt requires PHP 5.3 or above');

    if (self::is_legacy_hash($stored_hash)) {
      if ($legacy_handler) return call_user_func($legacy_handler, $password, $stored_hash);
      else throw new Exception('Unsupported hash format');
    }

    return crypt($password, $stored_hash) == $stored_hash;
  }

  public static function is_legacy_hash($hash) { return substr($hash, 0, 4) != '$2a$'; }
}

?>