PHP Encryption

defuse/php-encryption is a library that can be used to encrypt and decrypt data. Getting up and running is fairly simple to start encrypting and decrypting data. They have a great tutorial that helps explain the basics of how to use the library as well as important security implications regarding encryption.

Installation

Installation is simple with composer.

composer require defuse/php-encryption

Setup

Then you'll need to generate an encryption key.

vendor/bin/generate-defuse-key

This will spit out a key that you'll need to keep safe. You could keep the key in your app/config/config.php file in the array at the bottom of the file. While it's not the perfect spot, it's at least something.

Usage

Now that you have the library and an encryption key, you can start encrypting and decrypting data.

use Defuse\Crypto\Crypto;
use Defuse\Crypto\Key;

/*
 * Set in your bootstrap or public/index.php file
 */

// Encryption method
Flight::map('encrypt', function($raw_data) {
    $encryption_key = /* $config['encryption_key'] or a file_get_contents of where you put the key */;
    return Crypto::encrypt($raw_data, Key::loadFromAsciiSafeString($encryption_key));
});

// Decryption method
Flight::map('decrypt', function($encrypted_data) {
    $encryption_key = /* $config['encryption_key'] or a file_get_contents of where you put the key */;
    try {
        $raw_data = Crypto::decrypt($encrypted_data, Key::loadFromAsciiSafeString($encryption_key));
    } catch (Defuse\Crypto\Exception\WrongKeyOrModifiedCiphertextException $ex) {
        // An attack! Either the wrong key was loaded, or the ciphertext has
        // changed since it was created -- either corrupted in the database or
        // intentionally modified by Eve trying to carry out an attack.

        // ... handle this case in a way that's suitable to your application ...
    }
    return $raw_data;
});

Flight::route('/encrypt', function() {
    $encrypted_data = Flight::encrypt('This is a secret');
    echo $encrypted_data;
});

Flight::route('/decrypt', function() {
    $encrypted_data = '...'; // Get the encrypted data from somewhere
    $decrypted_data = Flight::decrypt($encrypted_data);
    echo $decrypted_data;
});