understrap/inc/security.php

<?php
/* Inspired by Simon Bradburys cleanup.php fromb4st theme https://github.com/SimonPadbury/b4st */
/*
Removes the generator tag with WP version numbers. Hackers will use this to find weak and old WP installs
*/
function no_generator()  { 
    return ''; 
}
add_filter( 'the_generator', 'no_generator' );

/*
Clean up wp_head() from unused or unsecure stuff
*/
remove_action('wp_head', 'wp_generator');
remove_action('wp_head', 'rsd_link');
remove_action('wp_head', 'wlwmanifest_link');
remove_action('wp_head', 'index_rel_link');
remove_action('wp_head', 'feed_links', 2);
remove_action('wp_head', 'feed_links_extra', 3);
remove_action('wp_head', 'adjacent_posts_rel_link_wp_head', 10, 0);
remove_action('wp_head', 'wp_shortlink_wp_head', 10, 0);
/*
Show less info to users on failed login for security.
(Will not let a valid username be known.)
*/
function show_less_login_info() { 
    return "<strong>ERROR</strong>: Stop guessing!"; 
}
add_filter( 'login_errors', 'show_less_login_info' );