Ok so i have seen this bit of code below on a script but im currently building a much simpler MVC and want to know how they somehow call the Encryption class with the Encryption::
so basically my question is how do i do the Encryption:: because i cant figure it out! Thanks
All help much appreciated!
Thanks
<?= Encryption::encryptId($user["id"]); ?>
They’re using static methods. That’s how you call a static method. You don’t call it using new Encryption(). Instead you call it by the namespace and class followed by two colons. However, you should not be using static methods. This SO post explains why. It can also be applied to different languages and not just PHP.
thanks i dont know why this is confusing me but please have a look at my autoloader
AUTOLOADER:
<?php
// Load Config
require_once 'config/config.php';
// Load Helpers
require_once 'helpers/url_helper.php';
require_once 'helpers/session_helper.php';
require_once 'helpers/imgsrc_helper.php';
//require_once 'libraries/Encryption.php';
// Load Libraries
// require_once 'libraries/Controller.php';
// require_once 'libraries/Core.php';
// require_once 'libraries/Database.php';
// Autoload Core Libraries
spl_autoload_register(function($className){
require_once 'libraries/' . $className . '.php';
});
?>
ENCRYPTION CLASS
<?php
class Encryption{
/**
* Cipher algorithm
*
* @var string
*/
const CIPHER = 'aes-256-cbc';
/**
* Hash function
*
* @var string
*/
const HASH_FUNCTION = 'sha256';
/**
* constructor for Encryption object.
*
* @access private
*/
private function __construct(){}
/**
* Encrypt an id.
*
* @access public
* @static static method
* @param integer|string $id
* @return string
* @see http://kvz.io/blog/2009/06/10/create-short-ids-with-php-like-youtube-or-tinyurl/
*/
public static function encryptId($id){
$encryptId = "";
$chars = self::getCharacters();
$base = strlen($chars);
$id = ((int)$id * 9518436) + 1142;
for ($t = ($id != 0 ? floor(log($id, $base)) : 0); $t >= 0; $t--) {
$bcp = bcpow($base, $t);
$a = floor($id / $bcp) % $base;
$encryptId = $encryptId . substr($chars, $a, 1);
$id = $id - ($a * $bcp);
}
return $encryptId;
}
/**
* Decryption for Id.
*
* @access public
* @static static method
* @param string $id
* @return integer
* @throws Exception if $id is empty
*/
public static function decryptId($id){
if(empty($id)){
throw new Exception("the id to decrypt can't be empty");
}
$decryptId = 0;
$chars = self::getCharacters();
$base = strlen($chars);
$len = strlen($id) - 1;
for ($t = $len; $t >= 0; $t--) {
$bcp = bcpow($base, $len - $t);
$decryptId += strpos($chars, substr($id, $t, 1)) * (int)$bcp;
}
return ((int)$decryptId - 1142) / 9518436;
}
/**
* Decryption for Ids with dash '-', Example: "feed-km1chg3"
*
* @access public
* @static static method
* @param string $id
* @return integer
* @throws Exception if $id is empty
*/
public static function decryptIdWithDash($id){
if(empty($id)){
throw new Exception("the id to decrypt can't be empty");
}
$decryptId = 0;
$chars = self::getCharacters();
$base = strlen($chars);
$id = explode("-", $id)[1];
$len = strlen($id) - 1;
for ($t = $len; $t >= 0; $t--) {
$bcp = bcpow($base, $len - $t);
$decryptId = $decryptId + strpos($chars, substr($id, $t, 1)) * (int)$bcp;
}
return ((int)$decryptId - 1142) / 9518436;
}
/**
* get characters that will be used in encryption/decryption provided by a key
*
* @access private
* @static static method
* @return string
* @throws Exception if $id is empty
*/
private static function getCharacters(){
$chars = 'abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
$i = [];
for ($n = 0; $n < strlen($chars); $n++) {
$i[] = substr($chars, $n, 1);
}
$key_hash = hash('sha256', Config::get('HASH_KEY'));
$key_hash = (strlen($key_hash) < strlen($chars) ? hash('sha512', Config::get('HASH_KEY')) : $key_hash);
for ($n = 0; $n < strlen($chars); $n++) {
$p[] = substr($key_hash, $n, 1);
}
array_multisort($p, SORT_DESC, $i);
$chars = implode($i);
return $chars;
}
/**
* Encrypt a string.
*
* @access public
* @static static method
* @param string $plain
* @return string
* @throws Exception If functions don't exists
*/
public static function encrypt($plain){
if(!function_exists('openssl_cipher_iv_length') ||
!function_exists('openssl_random_pseudo_bytes') ||
!function_exists('openssl_encrypt')){
throw new Exception("Encryption function don't exists");
}
// generate initialization vector,
// this will make $iv different every time,
// so, encrypted string will be also different.
$iv_size = openssl_cipher_iv_length(self::CIPHER);
$iv = openssl_random_pseudo_bytes($iv_size);
// generate key for authentication using ENCRYPTION_KEY & HMAC_SALT
$key = mb_substr(hash(self::HASH_FUNCTION, Config::get('ENCRYPTION_KEY') . Config::get('HMAC_SALT')), 0, 32, '8bit');
// append initialization vector
$encrypted_string = openssl_encrypt($plain, self::CIPHER, $key, OPENSSL_RAW_DATA, $iv);
$ciphertext = $iv . $encrypted_string;
// apply the HMAC
$hmac = hash_hmac('sha256', $ciphertext, $key);
return $hmac . $ciphertext;
}
/**
* Decrypted a string.
*
* @access public
* @static static method
* @param string $ciphertext
* @return string
* @throws Exception If $ciphertext is empty, or If functions don't exists
*/
public static function decrypt($ciphertext){
if(empty($ciphertext)){
throw new Exception("the string to decrypt can't be empty");
}
if(!function_exists('openssl_cipher_iv_length') ||
!function_exists('openssl_decrypt')){
throw new Exception("Encryption function don't exists");
}
// generate key used for authentication using ENCRYPTION_KEY & HMAC_SALT
$key = mb_substr(hash(self::HASH_FUNCTION, Config::get('ENCRYPTION_KEY') . Config::get('HMAC_SALT')), 0, 32, '8bit');
// split cipher into: hmac, cipher & iv
$macSize = 64;
$hmac = mb_substr($ciphertext, 0, $macSize, '8bit');
$iv_cipher = mb_substr($ciphertext, $macSize, null, '8bit');
// generate original hmac & compare it with the one in $ciphertext
$originalHmac = hash_hmac('sha256', $iv_cipher, $key);
if(!self::hashEquals($hmac, $originalHmac)){
return false;
}
// split out the initialization vector and cipher
$iv_size = openssl_cipher_iv_length(self::CIPHER);
$iv = mb_substr($iv_cipher, 0, $iv_size, '8bit');
$cipher = mb_substr($iv_cipher, $iv_size, null, '8bit');
return openssl_decrypt($cipher, self::CIPHER, $key, OPENSSL_RAW_DATA, $iv);
}
/**
* A timing attack resistant comparison.
*
* @access private
* @static static method
* @param string $hmac The hmac from the ciphertext being decrypted.
* @param string $compare The comparison hmac.
* @return bool
* @see https://github.com/sarciszewski/php-future/blob/bd6c91fb924b2b35a3e4f4074a642868bd051baf/src/Security.php#L36
*/
private static function hashEquals($hmac, $compare){
if (function_exists('hash_equals')) {
return hash_equals($hmac, $compare);
}
// if hash_equals() is not available,
// then use the following snippet.
// It's equivalent to hash_equals() in PHP 5.6.
$hashLength = mb_strlen($hmac, '8bit');
$compareLength = mb_strlen($compare, '8bit');
if ($hashLength !== $compareLength) {
return false;
}
$result = 0;
for ($i = 0; $i < $hashLength; $i++) {
$result |= (ord($hmac[$i]) ^ ord($compare[$i]));
}
return $result === 0;
}
}
ME TRYING TO GET THE CLASS
<?php echo Encryption::encryptId('2'); ?>
ERROR I GET
Warning: require_once(libraries/Config.php): failed to open stream: No such file or directory in C:\xampp\htdocs\scratch\app\bootstrap.php on line 19
Fatal error: require_once(): Failed opening required 'libraries/Config.php' (include_path='C:\xampp\php\PEAR') in C:\xampp\htdocs\scratch\app\bootstrap.php on line 19
Am i being blind or something because i can’t see why its not working!
LIBRARIES FOLDER
Thanks and you suggest i do something like this?
<?php
namespace App\Lib1;
class MyClass {
public function WhoAmI() {
return __METHOD__;
}
}
$c = __NAMESPACE__ . '\\MyClass';
$m = new $c;
echo $m->WhoAmI(); // outputs: App\Lib1\MyClass::WhoAmI
?>
but how does the above work with my autoloader?
Thanks very much
Where’s the bootstrap file? This error has nothing to do with your autoload. Look at the error and read it. It specifically says that it cannot find the file libraries/Config.php and it was required in your bootstrap file. Go and make sure Config.php exists in that location and is writable.
Any library that doesn’t integrate directly with composer I would only use if I was forced to. Otherwise I would seek an alternative. I’m sure there are more modern solutions out there than this. That package not being available as a composer package is a huge red flag for me.
the autoloader bit was the bootstrap.php file
I use composer for the PHPMailer etc but this is a custom MVC not the too bulky laravel etc. As much as i love laravel this is a small project so it is not required.
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