显示加密的数据库字段

Question

I have finally made the long overdue jump from PHP 5.6 to PHP 7.3 and upgraded mySQL to MariaDB. All seems to be working other than one app. I'm not bothered about trying to repair the code in the script, but I'd love to get a dump of the data.

Two of the fields are encrypted. I have the salt and encryption code, but I don't have the skills to be able to run a query that displays the encoded fields.

This is the encode function from the application:

function encode($string) {
$config     = &singleton::get(__NAMESPACE__ . '\config');
$error      = &singleton::get(__NAMESPACE__ . '\error');

$level      = $config->get('encryption_level');
$key        = $config->get('encryption_key');

switch ($level) {
    case 2:
        $error->create(array('type' => 'security_error', 'message' => 'Encode function cannot be used for this database security level.'));
    break;
    default:
        $encrypted  = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5($key), $string, MCRYPT_MODE_CBC, md5(md5($key))));      
    break;
}

return $encrypted;

}

Can anyone help?

Answer 1

We read the documentation :

mcrypt_encrypt ( string $cipher , string $key , string $data , string $mode [, string $iv ] ) : string

mcrypt_decrypt ( string $cipher , string $key , string $data , string $mode [, string $iv ] ) : string

so if this encrypts it:

$encrypted  = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5($key), $string, MCRYPT_MODE_CBC, md5(md5($key)));      

this will hopefully decrypt it:

$decrypted = base64_decode(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($key), $encrypted, MCRYPT_MODE_CBC, md5(md5($key)) ));

Answer 2

Thanks for the advice everyone. In the meantime I took a different approach, and loaded up a local PHP 5.6 instance on Wampserver and hey presto! The application lives again.

Now I can extract the information I need using cut'n'paste with the luxury of a working app. Not perfect, but it works.