Encrypt/Decrypt specific data in PHP

Question

I'm new to PHP, and I'm developing a web app for one of my subjects in college. The web app consists in platform to book nature activities. My problem is in one of the requirements, "encrypt/decrypt data", in which I need to encrypt the credit card data before it goes to the DB. For simplicity, the credit card fields are in the reservation table. This is my code:

$fieldsReservation = array(
    'idUser' => $idUser,
    'idActivity' => $idActivity,
    'reservationDate' => $reservationDate,
    'state' => 'reserved',
    'cardName' => $cardName,
    'cardType' => $cardType,
    'cardNumber' => $cardNumber,
    'cardExpiry' => $cardExpiry,
    'cardCVV' => $cardCVV);

$password = '3sc3RLrpd17';
$method = 'aes-256-cbc';

// password must be exact 32 chars (256 bit)
$password = substr(hash('sha256', $password, true), 0, 32);

// IV must be exact 16 chars (128 bit)
$iv = chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0);

foreach ($fieldsReservation as $key => $value){
    $fieldsReservation[$key] = base64_encode(openssl_encrypt($value, $method, $password, OPENSSL_RAW_DATA, $iv));
}

I already have tried with a foreach, but with a foreach, all data is encrypted, and i just want to encrypt the credit card data. If anyone could help me, I would be grateful!

Answer 1

It appears you would like to encrypt only the fields that contain card-related data, such as cardName, cardType, cardNumber etc. How about this:

foreach ($fieldsReservation as $key => $value){
  if (substr($key, 0, 4) == "card") {
    $fieldsReservation[$key] = 
      base64_encode(openssl_encrypt($value, $method, $password, OPENSSL_RAW_DATA, $iv));
  }
}

By looking at the each key, the code checks to see if it starts with "card". If so, its gets encrypted.