chlp

<?php
$change_from = 'old_string';
$change_to = 'new_string_new_length';
$serialized = file_get_contents('serialized_data.txt');
$serialized = str_replace($change_from, $change_to, $serialized);
function fix_str_length($matches) {
    $string = $matches[2];
    $right_length = strlen($string); // yes, strlen even for UTF-8 characters, PHP wants the mem size, not the char count
    return 's:' . $right_length . ':"' . $string . '";';
}

chlp

<?php

// ENCRYPTION
$method = 'AES-256-CBC';
$secret = 'my secret';
$key = 'test';
$hex_key = (bin2hex($key)); // example 74657374
$length = openssl_cipher_iv_length($method);
$iv = openssl_random_pseudo_bytes($length);
// $iv = hex2bin("047ed7c4aaf0069daa06b633b86aff67");

chlp

/**
 * Реализация API, не изменяйте ее
 * @param {string} url
 * @param {function} callback
 */
function getData(url, callback) {
    var RESPONSES = {
        '/countries': [
            {name: 'Cameroon', continent: 'Africa'},
            {name :'Fiji Islands', continent: 'Oceania'},