Disable wp-admin and wp-login

mu-plugin-disable-admin.php

<?php
/* 
Plugin Name: Disable Admin and Login 
Plugin URI: http://wordpress.stackexchange.com/a/106437/12615
Requires: PHP 5.3
*/

add_action( 'init', function() 
{
	$currentURL = $_SERVER["HTTP_HOST"] . $_SERVER["REQUEST_URI"];
	if( strpos( $currentURL, 'wp-admin' ) or strpos( $currentURL, 'wp-login' ) ) 
	{
		wp_redirect( site_url() );
		exit;
	}
});