class_CryptoHelper.php

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<?php
class CryptoHelper extends BaseFrameworkSystem implements Cryptable {
        // Exception constants
        const EXCEPTION_ENCRYPT_MISSING = 0x1f0;
        const EXCEPTION_ENCRYPT_INVALID = 0x1f1;

        private static $selfInstance = null;

        private $rngInstance = null;

        private $salt = "";

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

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

        public final static function createCryptoHelper () {
                // Get a new instance
                $cryptoInstance = new CryptoHelper();

                // Initialize the hasher
                $cryptoInstance->initHasher();

                // Return the instance
                return $cryptoInstance;
        }

        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;
        }

        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();
        }

        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);
        }

        public function hashString ($str, $oldHash = "") {
                // Cast the string
                $str = (string) $str;

                // Default is the default salt ;-)
                $salt = $this->salt;

                // Is the old password set?
                if (!empty($oldHash)) {
                        // 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);
                } // END - if

                // Hash the password with salt
                //* DEBUG: */ echo "salt=".$salt."/plain=".$str."<br />\n";
                $hashed = $salt . md5(sprintf($this->getConfigInstance()->readConfig('hash_mask'),
                        $salt,
                        $this->rngInstance->getFixedSalt(),
                        $str
                ));

                // And return it
                return $hashed;
        }

        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());
                }

                // Add some "garbage" to the string
                switch ($this->rngInstance->randomNumber(0, 8)) {
                        case 0:
                                $garbageString = crc32($this->rngInstance->randomString(10))."|".base64_encode($str)."|".crc32($this->rngInstance->randomString(20));
                                break;

                        case 1:
                                $garbageString = crc32($this->rngInstance->randomString(10))."|".base64_encode($str)."|".md5($this->rngInstance->randomString(20));
                                break;

                        case 2:
                                $garbageString = crc32($this->rngInstance->randomString(10))."|".base64_encode($str)."|".sha1($this->rngInstance->randomString(20));
                                break;

                        case 3:
                                $garbageString = md5($this->rngInstance->randomString(10))."|".base64_encode($str)."|".crc32($this->rngInstance->randomString(20));
                                break;

                        case 4:
                                $garbageString = md5($this->rngInstance->randomString(10))."|".base64_encode($str)."|".md5($this->rngInstance->randomString(20));
                                break;

                        case 5:
                                $garbageString = md5($this->rngInstance->randomString(10))."|".base64_encode($str)."|".sha1($this->rngInstance->randomString(20));
                                break;

                        case 6:
                                $garbageString = sha1($this->rngInstance->randomString(10))."|".base64_encode($str)."|".crc32($this->rngInstance->randomString(20));
                                break;

                        case 7:
                                $garbageString = sha1($this->rngInstance->randomString(10))."|".base64_encode($str)."|".md5($this->rngInstance->randomString(20));
                                break;

                        case 8:
                                $garbageString = sha1($this->rngInstance->randomString(10))."|".base64_encode($str)."|".sha1($this->rngInstance->randomString(20));
                                break;
                }

                // Encrypt the string
                $encrypted = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $garbageString, MCRYPT_MODE_ECB, $iv);

                // Return the string
                return $encrypted;
        }

        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());
                }

                // Decrypt the string
                $garbageString = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, $encrypted, MCRYPT_MODE_ECB, $iv);

                // Get the real string out
                $strArray = explode("|", $garbageString);

                // Does the element count match?
                assert(count($strArray) == 3);

                // Decode the string
                $str = base64_decode($strArray[1]);

                // Trim trailing nulls away
                $str = rtrim($str, "\0");

                // Return the string
                return $str;
        }
}

// [EOF]
?>