PHP AES Encryption and Decryption Using OpenSSL

AES encryption in PHP5 used the mcrypt_decrypt function, which has been deprecated after PHP 7.1; the modern replacement is OpenSSL's openssl_encrypt and openssl_decrypt . The following compact class implements both operations.

<?php class Aes { public $key = ''; public $iv = ''; public function __construct($config) { foreach ($config as $k => $v) { $this->$k = $v; } } // Encryption public function aesEn($data) { return base64_encode(openssl_encrypt($data, $this->method, $this->key, OPENSSL_RAW_DATA, $this->iv)); } // Decryption public function aesDe($data) { return openssl_decrypt(base64_decode($data), $this->method, $this->key, OPENSSL_RAW_DATA, $this->iv); } } ?>

The class is configured with an associative array specifying the encryption key, a 16‑byte IV generated via md5(time().uniqid(), true) , and the method (e.g., 'AES-128-CBC' ).

<?php $config = [ // encryption key 'key' => 'aaaabbbbcccc', // ensure IV is 16 bytes 'iv' => md5(time().uniqid(), true), // encryption method 'method' => 'AES-128-CBC', ]; $obj = new Aes($config); $res = $obj->aesEn('123456789'); // encrypted data echo $res; ?>

To decrypt, instantiate the class with the same configuration and call aesDe on the encrypted string.

<?php $obj = new Aes($config); $decrypted = $obj->aesDe($res); echo $decrypted; // outputs original data ?>

This approach allows developers to hide sensitive parameters and data by encrypting them before transmission, ensuring that only the backend can decrypt and process the original information.