class_RandomNumberGenerator.php

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<?php
class RandomNumberGenerator extends BaseFrameworkSystem {
        private $prime = 0;

        private $extraNumber = 0;

        private $extraSalt = "";

        private $fixedSalt = "";

        private $rndStrLen = 0;

        protected function __construct ($className = __CLASS__) {
                // Call parent constructor
                parent::__construct($className);

                // Clean up a little
                $this->removeNumberFormaters();
                $this->removeSystemArray();
        }

        public final static function createRandomNumberGenerator (FrameworkInterface $extraInstance = null) {
                // Get a new instance
                $rngInstance = new RandomNumberGenerator();

                // Initialize the RNG now
                $rngInstance->initRng($extraInstance);

                // Return the instance
                return $rngInstance;
        }

        protected function initRng ($extraInstance) {
                // Get the prime number from config
                $this->prime = $this->getConfigInstance()->readConfig('math_prime');

                // Calculate the extra number which is always the same unless you give
                // a better prime number
                $this->extraNumber = ($this->prime * $this->prime / (pi() ^ 2));

                // Seed mt_rand()
                mt_srand((double) sqrt(microtime() * 100000000 * $this->extraNumber));

                // Set the server IP to cluster
                $serverIp = "cluster";

                // Do we have a single server?
                if ($this->getConfigInstance()->readConfig('is_single_server') === "Y") {
                        // Then use that IP for extra security
                        $serverIp = getenv('SERVER_ADDR');
                } // END - if

                // Yet-another fixed salt. This is not dependend on server software or date
                if ($extraInstance instanceof FrameworkInterface) {
                        // With extra instance information
                        $this->fixedSalt = sha1($serverIp . ":" . $extraInstance->__toString() . ":" . serialize($this->getDatabaseInstance()->getConnectionData()));
                } else {
                        // Without extra information
                        $this->fixedSalt = sha1($serverIp . ":" . serialize($this->getDatabaseInstance()->getConnectionData()));
                }

                // One-way data we need for "extra-salting" the random number
                $this->extraSalt = sha1($this->fixedSalt . ":" . getenv('SERVER_SOFTWARE') . ":" . $this->getConfigInstance()->readConfig('date_key') . $this->getConfigInstance()->readConfig('base_url'));

                // Get config entry for max salt length
                $this->rndStrLen = $this->getConfigInstance()->readConfig('rnd_str_length');
        }

        public function randomString ($length = -1) {
                // Is the number <1, then fix it to default length
                if ($length < 1) $length = $this->rndStrLen;

                // Initialize the string
                $randomString = "";

                // And generate it
                for ($idx = 0; $idx < $length; $idx++) {
                        // Add a random character and add it to our string
                        $randomString .= chr($this->randomNumber(0, 255));
                }

                // Return the random string a little mixed up
                return str_shuffle($randomString);
        }

        public function randomNumber ($min, $max) {
                return mt_rand($min, $max);
        }

        public final function getExtraSalt () {
                return $this->extraSalt;
        }

        public final function getFixedSalt () {
                return $this->fixedSalt;
        }
}

// [EOF]
?>