encryptdandecript model openssl

<?php

//encrypt dcrypt sederhana
//keisengan untuk keisengan
//created by kakatoji

function encrypt_decrypt($action, $string) {
    $output = false;
    $encrypt_method = "AES-256-CBC";
    $secret_key = 'key_one';
    $secret_iv = 'key_two';
    $key = hash('sha256', $secret_key);
    $iv = substr(hash('sha256', $secret_iv), 0, 16);
    if ( $action == 'encrypt' ) {
        $output = openssl_encrypt($string, $encrypt_method, $key, 0, $iv);
        $output = base64_encode($output);
    } else if( $action == 'decrypt' ) {
        $output = openssl_decrypt(base64_decode($string), $encrypt_method, $key, 0, $iv);
    }
    return $output;
}
// Contoh Penggunaan
$plain_txt = "hai salam kenal saya kakatoji";
$encrypted_txt = encrypt_decrypt('encrypt', $plain_txt);
$decrypted_txt = encrypt_decrypt('decrypt', $encrypted_txt);
echo $encrypted_txt;