Sensitive Parameter Attribute in PHP 8.2

TheDevick,New in PHP 8.2

An sensitive Parameter have its value hidden if present in a stack trace.

An Secret Parameter 🕵️‍♂️

Let's have an example that we're making a request to an Api that needs an Api Token, and the Application will throw an Exception if have any error with this Api Token.

function makeApiRequest(string $apiToken): Response
    $client = new Client();
    $res = $client->get('', [
        'auth' => ['apiToken', $apiToken]
    if($res->getStatusCode() === 403) {
        throw new Exception("Wrong Api Token");
    return $res;

If we run this code, and the example Api returns the 403 status code, the application will trow an Wrong Api Token Exception:

Fatal error: Uncaught Exception: Wrong Api Token in /app/App.php:15
Stack trace:
#0 /app/App.php(21): makeApiRequest('Secret Token')
#1 {main}
  thrown in /app/App.php on line 15

You can note that in the Stack Trace, the "Secret Token" value is Appearing. Well, this can be an Big Security Problem.

The Sensitive Parameter Attribute 🤿

The new Sensitive Parameter Attribute, added in PHP 8.2 focus on solve this problem. We can target an Property with this Attribute and it will be Hidden in the Stack Trace. In our case:

function makeApiRequest(#[SensitiveParameter] string $apiToken): Response

The Logs:

Fatal error: Uncaught Exception: Wrong Api Token in /app/App.php:15
Stack trace:
#0 /app/App.php(21): makeApiRequest(Object(SensitiveParameterValue))
#1 {main}
  thrown in /app/App.php on line 15

We can see that, now, the Secret Api Key isn't appearing anymore. Instead, have an SensitiveParameterValue object. This object have an interesting feature: the getValue() method, which allows the Developer to get the hidden value of the parameter.

Sources ✨

© Erick Bilhalba Abella.