Magento 1.9.3.7 with PHP7.1：不推荐使用mcrypt

Question

I've got a Magento 1.9.3.7 version and updated php5.4 to php7.1. Now some of my unittest fail with the error: "Deprecated functionality: Function mcrypt_module_open() is deprecated in /path/to/deprecated/method". Now I want to replace mcrypt with openssl. How is the general procedure and where is the point where I magento say which encryption to use.

My consideration is the following: I create a new file named "Openssl.php" in the folder "app/code/local/Varien/Crypt/" now i say to Magento it should use openssl instead of mcrypt (but I don't know where). Is that the right approach? For examples, I would be grateful.

Thank you in advance

Answer 1

In fact, better and easiest solution is to install phpseclib/mcrypt_compat which is PHP 5.x/7.x polyfill for mcrypt extension.

Install this extention via composer and disable mcrypt.