PHP7.1 and Laravel 5.3: Function mcrypt_get_iv_size() is deprecated

Question

I'm using Laravel 5.0 for all my projects. Yesterday, I've updated my PHP version from 7.0.x to version 7.1.0. Once updated, I tried opening my Laravel project and saw this message below:

ErrorException in Encrypter.php line 303: 
Function mcrypt_get_iv_size() is deprecated

in Encrypter.php line 303
at HandleExceptions->handleError('8192', 'Function mcrypt_get_iv_size() is deprecated', 'C:\wamp64\www\project1\vendor\laravel\framework\src\Illuminate\Encryption\Encrypter.php', '303', array()) in Encrypter.php line 303

May I know how can I solve this ? Does using Laravel 5.3 solve the problem? I don't feel like updating my Laravel to 5.3 because it's a huge project and it will takes a long time to update. There are too much differences between these two versions. Lots of codes need to be modified.

Is there an easier way to solve this issue?

Answer 1

This error occurs because you probably have something other than AES-256-CBC as your cipher in your config/app.php file that depends on the mcrypt extension. Perhaps you are using MCRYPT_RIJNDAEL_256 or MCRYPT_RIJNDAEL_128?

The best thing you can do without a full-blown Laravel upgrade is install the legacy encrypter and use it to update all your encrypted data to use the AES-256-CBC cipher which has been the default cipher since Laravel 5.1, I believe. Once you do this, you should be able to use PHP 7.1 for your Laravel application.

Answer 2

Add this to the beginning of the config/app.php:

error_reporting(E_ALL ^ E_DEPRECATED);

Source: https://stackoverflow.com/a/42515505/225790