解密CakePHP 1.2数据

Question

I have an application that was build on CakePHP 1.2, and stored some encrypted data. I am rebuilding the application and need to decrypt the data in the new app to update the encryption on it. The ciphers and methods used to encrypt the data in CakePHP 1.2 are not available in PHP 7.1+. Does anyone know of a way that I can decrypt the data in a PHP 7.1+ environment so that it can be encrypted with newer technologies?

Current method that encrypts/decrypts data

function _cryptData(&$data, $direction) {
    $ivSize = mcrypt_get_iv_size(MCRYPT_TRIPLEDES, MCRYPT_MODE_CBC);
    switch ($direction) {
        case 'encrypt':
            $iv = mcrypt_create_iv($ivSize, MCRYPT_RAND);
            $data = base64_encode($iv) . '|' . base64_encode(mcrypt_encrypt(MCRYPT_TRIPLEDES, Configure::read('CakeMix.cryptKey'), $data, MCRYPT_MODE_CBC, $iv));
            break;
        case 'decrypt':
            list($iv, $encoded) = explode('|', $data);
            $data = mcrypt_decrypt(MCRYPT_TRIPLEDES, Configure::read('CakeMix.cryptKey'), base64_decode($encoded), MCRYPT_MODE_CBC, base64_decode($iv));
            break;
    }

}

Answer 1

The shown code in your question seems to be custom, ie non-CakePHP core code, so this seem more just PHP related.

Mcrypt is deprecated, but still available in PHP 7.1, it has only been removed as of PHP 7.2. Mcrypt can also still be used with PHP 7.2+, you'd just have to install it manually, as it's been moved to PECL , see for example Issue in installing php7.2-mcrypt . You could also use a polyfill like phpseclib/mcrypt_compat . So you should be able to continue using Mcrypt for decryption, and port the data to whatever encryption you like.

Furthermore it should generally also be possible to decrypt the data using OpenSSL, though there seem to be pitfalls around null padding, see for example Decrypt mcrypt with openssl . Here's a basic example:

$data = openssl_decrypt(
    base64_decode($encoded),
    'des-ede3-cbc',
    Configure::read('CakeMix.cryptKey'),
    OPENSSL_RAW_DATA | OPENSSL_NO_PADDING,
    base64_decode($iv)
);

There's quite a lot of topics on replacing Mcrypt with OpenSSL, which you may want to have a look at for further options.