3 * A standard random number generator
5 * @author Roland Haeder <webmaster@ship-simu.org>
7 * @copyright Copyright(c) 2007, 2008 Roland Haeder, this is free software
8 * @license GNU GPL 3.0 or any newer version
9 * @link http://www.ship-simu.org
11 * This program is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 3 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 class RandomNumberGenerator extends BaseFrameworkSystem {
26 * Prime number for better pseudo random numbers
31 * Add this calculated number to the rng
33 private $extraNumber = 0;
36 * Extra salt for secured hashing
38 private $extraSalt = "";
41 * Fixed salt for secured hashing
43 private $fixedSalt = "";
46 * Maximum length for random string
48 private $rndStrLen = 0;
51 * Protected constructor
53 * @param $className Name of this class
56 protected function __construct ($className = __CLASS__) {
57 // Call parent constructor
58 parent::__construct($className);
60 // Set part description
61 $this->setObjectDescription("Standard random number generator");
63 // Create unique ID number
64 $this->generateUniqueId();
67 $this->removeNumberFormaters();
68 $this->removeSystemArray();
72 * Creates an instance of this class
74 * @param $extraInstance An extra instance for more salt (default: null)
75 * @return $rngInstance An instance of this random number generator
77 public final static function createRandomNumberGenerator (FrameworkInterface $extraInstance = null) {
79 $rngInstance = new RandomNumberGenerator();
81 // Initialize the RNG now
82 $rngInstance->initRng($extraInstance);
84 // Return the instance
89 * Initializes the random number generator
91 * @param $extraInstance An extra instance for more salt (default: null)
93 * @todo Add site key for stronger salt!
95 protected function initRng ($extraInstance) {
96 // Get the prime number from config
97 $this->prime = $this->getConfigInstance()->readConfig('math_prime');
99 // Calculate the extra number which is always the same unless you give
100 // a better prime number
101 $this->extraNumber = ($this->prime * $this->prime / (pi() ^ 2));
104 mt_srand((double) sqrt(microtime() * 100000000 * $this->extraNumber));
106 // Set the server IP to cluster
107 $serverIp = "cluster";
109 // Do we have a single server?
110 if ($this->getConfigInstance()->readConfig('is_single_server') == "Y") {
111 // Then use that IP for extra security
112 $serverIp = getenv('SERVER_ADDR');
115 // Yet-another fixed salt. This is not dependend on server software or date
116 if ($extraInstance instanceof FrameworkInterface) {
117 // With extra instance information
118 $this->fixedSalt = sha1($serverIp . ":" . $extraInstance->__toString() . ":" . serialize($this->getDatabaseInstance()->getConnectionData()) . ":" . $extraInstance->getObjectDescription());
120 // Without extra information
121 $this->fixedSalt = sha1($serverIp . ":" . serialize($this->getDatabaseInstance()->getConnectionData()));
124 // One-way data we need for "extra-salting" the random number
125 $this->extraSalt = sha1($this->fixedSalt . ":" . getenv('SERVER_SOFTWARE') . ":" . $this->getConfigInstance()->readConfig('date_key') . $this->getConfigInstance()->readConfig('base_url'));
127 // Get config entry for max salt length
128 $this->rndStrLen = $this->getConfigInstance()->readConfig('rnd_str_length');
132 * Makes a pseudo-random string useable for salts
134 * @param $length Length of the string, default: 128
135 * @return $randomString The pseudo-random string
137 public function randomString ($length = -1) {
138 // Is the number <1, then fix it to default length
139 if ($length < 1) $length = $this->rndStrLen;
141 // Initialize the string
145 for ($idx = 0; $idx < $length; $idx++) {
146 // Add a random character and add it to our string
147 $randomString .= chr($this->randomNumber(0, 255));
150 // Return the random string a little mixed up
151 return str_shuffle($randomString);
155 * Generate a pseudo-random integer number in a given range
157 * @param $min Min value to generate
158 * @param $max Max value to generate
159 * @return $num Pseudo-random number
160 * @todo I had a better random number generator here but now it is somewhere lost :(
162 public function randomNumber ($min, $max) {
163 return mt_rand($min, $max);
167 * Getter for extra salt
171 public final function getExtraSalt () {
172 return $this->extraSalt;
176 * Getter for fixed salt
180 public final function getFixedSalt () {
181 return $this->fixedSalt;