Argument 2 passed to Safe\openssl_sign() must be of the type string, null given

[JanMikes]

Hello!

I have following code:

// $this->privateKey is resource
$digestText = '';
\Safe\openssl_sign($digestText, $signature, $this->privateKey);

And i get following error: Argument 2 passed to Safe\openssl_sign() must be of the type string, null given

I can get this fixed by adding $signature = '' before calling openssl_sign(). I understand the error, but i expected (and it worked before using Safe package), that $signature variable will get created 😄

[moufmouf]

Hey @JanMikes ,

Ok, I can confirm I reproduced the issue in this unit test: #91 .
Still have to find a workaround!

[moufmouf]

Ok, found a way.

The PHPStan function map tells us if a parameter passed by reference (like $signature) is supposed to be used for read and write or for write only.

Typically, $signature is a write only parameter. Any write only parameter should be considered as nullable (even if they are not documented as such), since we can put null in input and they will produce a string output.

PHPStan's functionMap.php

'openssl_sign' => ['bool', 'data'=>'string', '&w_signature'=>'string', 'priv_key_id'=>'resource|string', 'signature_alg='=>'int|string'],

The "w_" in the file denotes the "write only" mode.

[JanMikes]

Thank you very much, I will try it out.

[moufmouf]

Fixed in #91