Your IP : 216.73.216.87
<?php
namespace Cleantalk\Antispam;
class Encoder
{
private $cipher_algo = "AES-128-CBC";
private $secret_key;
private $encrypted_string_splitter;
private $encryption_is_available;
private $use_ssl = true;
public function __construct($api_key)
{
$this->secret_key = md5($api_key);
$this->encrypted_string_splitter = substr($this->secret_key, 0, 3);
$this->encryption_is_available = function_exists('openssl_encrypt') &&
function_exists('openssl_decrypt') &&
function_exists('openssl_cipher_iv_length') &&
function_exists('openssl_random_pseudo_bytes') &&
!empty($this->encrypted_string_splitter) && strlen($this->encrypted_string_splitter) === 3;
}
/**
* @param bool $use_ssl
*
* @return void
*/
public function useSSL($use_ssl)
{
$this->use_ssl = $use_ssl;
}
/**
* Decoding previously encoded string
*
* @param $encoded_string string
*
* @return string
*/
public function decodeString($encoded_string)
{
if ( $this->use_ssl && $this->encryption_is_available ) {
$decoded_string = htmlspecialchars_decode($this->openSSLDecrypt($encoded_string));
} else {
$decoded_string = htmlspecialchars_decode(base64_decode($encoded_string));
$decoded_string = str_rot13($decoded_string);
}
return $decoded_string;
}
/**
* Encoding any string
*
* @param $plain_string string
*
* @return string
*/
public function encodeString($plain_string)
{
if ( $this->use_ssl && $this->encryption_is_available ) {
$encoded_email = htmlspecialchars($this->openSSLEncrypt($plain_string));
} else {
$encoded_email = htmlspecialchars(base64_encode(str_rot13($plain_string)));
}
return $encoded_email;
}
/**
* Encrypts a given plain string using the AES-128-CBC cipher algorithm and returns the encoded string.
*
* @param string $plain_string The plain text string that needs to be encrypted.
* @return string The encrypted string, which is a combination of the base64-encoded initialization vector (IV) and the encrypted data, separated by a predefined splitter.
*/
private function openSSLEncrypt($plain_string)
{
global $apbct;
try {
if (!is_string($plain_string) || empty($plain_string)) {
throw new \Exception('Invalid or empty plain string');
}
// Determine the length of the IV required for the AES-128-CBC cipher algorithm
$iv_length = openssl_cipher_iv_length($this->cipher_algo);
if ($iv_length === false) {
throw new \Exception('Can\'t generate initializing vector length');
}
// Generate a random IV of the required length
$iv = openssl_random_pseudo_bytes($iv_length);
if (empty($iv)) {
throw new \Exception('Can\'t generate initializing vector body');
}
// Encrypt the plain string using the specified cipher algorithm, secret key, and IV
$encoded_string = @openssl_encrypt($plain_string, $this->cipher_algo, $this->secret_key, 0, $iv);
if (empty($encoded_string)) {
throw new \Exception('Can\'t encode plain string');
}
if (!function_exists('base64_encode')) {
throw new \Exception('Can\'t run base64_encode');
}
// Base64-encode the IV and concatenate it with the encrypted string, separated by a predefined splitter
$encoded_string = base64_encode($iv) . $this->encrypted_string_splitter . $encoded_string;
// Return the combined string
return $encoded_string;
} catch (\Exception $e) {
//todo catch errors on higher level
$get_last_error = error_get_last();
$get_last_error = isset($get_last_error['message']) ? $get_last_error['message'] : 'no PHP error';
$apbct->errorAdd('email_encoder', esc_html($e->getMessage()) . ', backtrace: ' . $get_last_error);
return $plain_string;
}
}
/**
* Decrypts a given encoded string using the AES-128-CBC cipher algorithm and returns the decoded string.
*
* @param string $encoded_string The encoded string that needs to be decrypted.
* @return string The decrypted string.
*/
private function openSSLDecrypt($encoded_string)
{
global $apbct;
try {
if (!is_string($encoded_string) || empty($encoded_string)) {
throw new \Exception('Invalid or empty encoded string');
}
// Find the position of the splitter in the encoded string
$splitter_position = strpos($encoded_string, $this->encrypted_string_splitter);
if (empty($splitter_position)) {
throw new \Exception('Can\'t split string');
}
// Extract the IV chunk from the encoded string
$iv_chunk = substr($encoded_string, 0, $splitter_position);
if (empty($iv_chunk)) {
throw new \Exception('Can\'t get initializing vector string');
}
// Extract the encoded data chunk from the encoded string
$encoded_data_chunk = substr($encoded_string, $splitter_position + strlen($this->encrypted_string_splitter));
if (empty($encoded_data_chunk)) {
throw new \Exception('Can\'t get encoded data');
}
if (!function_exists('base64_decode')) {
throw new \Exception('Can\'t run base64_decode');
}
// Decode the IV chunk from base64
$iv_chunk_decoded = base64_decode($iv_chunk);
if (empty($iv_chunk_decoded)) {
throw new \Exception('Can\'t decode initializing vector string');
}
// Decrypt the encoded data chunk using the specified cipher algorithm, secret key, and IV
$decoded_string = @openssl_decrypt($encoded_data_chunk, $this->cipher_algo, $this->secret_key, 0, $iv_chunk_decoded);
if (empty($decoded_string)) {
throw new \Exception('Can\'t finish SSL decryption');
}
// Return the decrypted string
return $decoded_string;
} catch (\Exception $e) {
//todo catch errors on higher level
$get_last_error = error_get_last();
$get_last_error = isset($get_last_error['message']) ? $get_last_error['message'] : 'no PHP error';
$apbct->errorAdd('email_encoder', esc_html($e->getMessage()) . ', backtrace: ' . $get_last_error);
return '';
}
}
}