Call to undefined function openssl_encrypt () in Xampp

I just changed the php version I'm using in Xampp (to a lower version) and I'm having errors with the encryption functions. In other similar questions I saw that it was worth removing the; before extension=php_openssl.dll in php.ini (use windows), but it has not worked for me. I have tried to use the mcrypt_module_open() function by uncommenting the lines extension=php_mcrypt.dll and extension=php_mcrypt_filter.dll , but I have the same problem. I have done this operation with all the .ini that I have found but nothing. I've also seen answers where they say you have to modify the file phpForApache.ini , but I do not have such a file.

My code, which worked with PHP 7, is as follows:

function encrypt_decrypt($string, $action, $encrypt_method, $key, $iv) 
        {

        $resultado = false; 

        if( $action == 'e' ) 
        {
            $resultado = base64_encode( openssl_encrypt( $string, $encrypt_method, $key, 0, $iv ) );
        }
        else if( $action == 'd' )
        {
            $resultado = openssl_decrypt( base64_decode( $string ), $encrypt_method, $key, 0, $iv );
        }

        return $resultado;
        };