* @version 0.0.0
* @copyright Copyright(c) 2007, 2008 Roland Haeder, this is free software
* @license GNU GPL 3.0 or any newer version
* @link http://www.ship-simu.org
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
class CryptoHelper extends BaseFrameworkSystem implements Cryptable {
/**
* An instance of this own clas
*/
private static $selfInstance = null;
/**
* Instance of the random number generator
*/
private $rngInstance = null;
/**
* Salt for hashing operations
*/
private $salt = "";
/**
* Protected constructor
*
* @return void
*/
protected function __construct () {
// Call parent constructor
parent::__construct(__CLASS__);
// Set part description
$this->setObjectDescription("Cryptographical helper");
// Create unique ID number
$this->generateUniqueId();
// Clean up a little
$this->removeNumberFormaters();
$this->removeSystemArray();
}
/**
* Creates an instance of this class
*
* @return $cryptoInstance An instance of this crypto helper class
*/
public final static function createCryptoHelper () {
// Get a new instance
$cryptoInstance = new CryptoHelper();
// Initialize the hasher
$cryptoInstance->initHasher();
// Return the instance
return $cryptoInstance;
}
/**
* Get a singleton instance of this class
*
* @return $selfInstance An instance of this crypto helper class
*/
public final static function getInstance () {
// Is no instance there?
if (is_null(self::$selfInstance)) {
// Then get a new one
self::$selfInstance = self::createCryptoHelper();
}
// Return the instance
return self::$selfInstance;
}
/**
* Initializes the hasher for different purposes.
*
* @return void
*/
protected function initHasher () {
// Initialize the random number generator which is required by some crypto methods
$this->rngInstance = ObjectFactory::createObjectByConfiguredName('rng_class');
// Generate a salt for the hasher
$this->generateSalt();
}
/**
* Generates the salt based on configured length
*
* @return void
*/
private function generateSalt () {
// Get a random string from the RNG
$randomString = $this->rngInstance->randomString();
// Get config entry for salt length
$length = $this->getConfigInstance()->readConfig('salt_length');
// Keep only defined number of characters
$this->salt = substr(sha1($randomString), -$length, $length);
}
/**
* Hashes a string with salt and returns the hash. If an old previous hash
* is supplied the method will use the first X chars of that hash for hashing
* the password. This is useful if you want to check if the password is
* identical for authorization purposes.
*
* @param $str Unhashed string
* @param $oldHash A hash from previous hashed string
* @return $hashed The hashed and salted string
*/
public function hashString ($str, $oldHash = "") {
// Cast the string
$str = (string) $str;
// Is the old password set?
if (empty($oldHash)) {
// No, then use the current salt
$salt = $this->salt;
} else {
// Use the salt from hash, first get length
$length = $this->getConfigInstance()->readConfig('salt_length');
// Then extract the X first characters from the hash as our salt
$salt = substr($oldHash, 0, $length);
}
// Hash the password with salt
//* DEBUG: */ echo "salt=".$salt."/plain=".$str."
\n";
$hashed = $salt . md5(sprintf($this->getConfigInstance()->readConfig('hash_mask'),
$salt,
$this->rngInstance->getFixedSalt(),
$str
));
// And return it
return $hashed;
}
/**
* Encrypt the string with fixed salt
*
* @param $str The unencrypted string
* @return $encrypted Encrypted string
*/
public function encryptString ($str) {
// Init crypto module
$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
// Get key
if ($this->getConfigInstance()->readConfig('crypt_fixed_salt') == "Y") {
$key = md5($this->rngInstance->getFixedSalt());
} else {
$key = md5($this->rngInstance->getExtraSalt());
}
// Encrypt the string
$encrypted = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $str, MCRYPT_MODE_ECB, $iv);
// Return the string
return $encrypted;
}
/**
* Decrypt the string with fixed salt
*
* @param $encrypted Encrypted string
* @return $str The unencrypted string
*/
public function decryptString ($encrypted) {
// Init crypto module
$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
// Get key
if ($this->getConfigInstance()->readConfig('crypt_fixed_salt') == "Y") {
$key = md5($this->rngInstance->getFixedSalt());
} else {
$key = md5($this->rngInstance->getExtraSalt());
}
// Encrypt the string
$str = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, $encrypted, MCRYPT_MODE_ECB, $iv);
// Trim trailing nulls away
$str = rtrim($str, "\0");
// Return the string
return $str;
}
}
// [EOF]
?>