wp_security-performance.php

<?php
/**
 * Add security and performance enhancements
 *
 */

// Exit if accessed directly.
defined( 'ABSPATH' ) || exit;

// remove version from head
remove_action('wp_head', 'wp_generator');

// remove version from rss
add_filter('the_generator', '__return_empty_string');

// remove version from scripts and styles
function branode_remove_version_scripts_styles($src) {
	if (strpos($src, 'ver=')) {
		$src = remove_query_arg('ver', $src);
	}
	return $src;
}
add_filter('style_loader_src', 'branode_remove_version_scripts_styles', 9999);
add_filter('script_loader_src', 'branode_remove_version_scripts_styles', 9999);

//Remove Dashicons for not logged in users
add_action( 'wp_print_styles', 'dashicons_dequeue_styles' );
function dashicons_dequeue_styles() { 
	if ( ! is_user_logged_in() ) {
		wp_dequeue_style( 'dashicons' );
		wp_deregister_style( 'dashicons' );
	}
}

/**
 * Disable the emoji's
 */
function disable_emojis() {
	remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
	remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
	remove_action( 'wp_print_styles', 'print_emoji_styles' );
	remove_action( 'admin_print_styles', 'print_emoji_styles' ); 
	remove_filter( 'the_content_feed', 'wp_staticize_emoji' );
	remove_filter( 'comment_text_rss', 'wp_staticize_emoji' ); 
	remove_filter( 'wp_mail', 'wp_staticize_emoji_for_email' );
	add_filter( 'tiny_mce_plugins', 'disable_emojis_tinymce' );
	add_filter( 'wp_resource_hints', 'disable_emojis_remove_dns_prefetch', 10, 2 );
}
add_action( 'init', 'disable_emojis' );

/**
 * Filter function used to remove the tinymce emoji plugin.
 * 
 * @param array $plugins 
 * @return array Difference betwen the two arrays
 */
function disable_emojis_tinymce( $plugins ) {
	if ( is_array( $plugins ) ) {
		return array_diff( $plugins, array( 'wpemoji' ) );
	} else {
		return array();
	}
}

/**
 * Remove emoji CDN hostname from DNS prefetching hints.
 *
 * @param array $urls URLs to print for resource hints.
 * @param string $relation_type The relation type the URLs are printed for.
 * @return array Difference betwen the two arrays.
 */
function disable_emojis_remove_dns_prefetch( $urls, $relation_type ) {
	if ( 'dns-prefetch' == $relation_type ) {
		/** This filter is documented in wp-includes/formatting.php */
		$emoji_svg_url = apply_filters( 'emoji_svg_url', 'https://s.w.org/images/core/emoji/2/svg/' );

		$urls = array_diff( $urls, array( $emoji_svg_url ) );
	}
	return $urls;
}

/**
 * WordPress Fail Login return 401
 *
 * Useful in use with a login failure daemon like Fail2ban or CSF
 */
function branode_login_failed_401() {
	status_header( 401 );
}
add_action( 'wp_login_failed', 'branode_login_failed_401' );