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http://www.co-internet.net/net/articles/protectlistings.txt.html

Protecting Your Server From Unwanted Directory Listings
-------------------------------------------------------
by
Dirk Brockhausen
-------------------------------------------------------

When a URL is called which isn't pointing to a file but
merely to a directory, the server will look for the
default documents.

These are defined in the server's configuration file.

Let's look at a practical example. A visitor enter the
following URL in his or her web browser:

< http://yourdomain.com >

The webserver will expand the URL, depending on
configuration, to:

< http://yourdomain.com/index.html >
< http://yourdomain.com/index.htm >
< http://yourdomain.com/default.htm >
< http://yourdomain.com/home.htm >

If none of the default documents is found, the web
server will display the directory listing by default.

This, of course, will inadvertently reveal document
names to your visitor which can then be downloaded
directly, e.g.:

< http://yourdomain.com/private/private.html >


To protect against this unwanted display, a common
approach is to copy a default document into each
directory, e.g. "index.html".

The default document can be empty, even a file of 0
bytes will suffice.

Instead, you may also configure the file to redirect
the visitor via a meta refresh e.g. to your home page
file "index.html" in the main directory.


However, this protection measure is somewhat
cumbersome, especially so if you have a multitude of
directories to protect from snooping eyes.

A better method consists of configuring the web server
accordingly. Drawing on the Apache web server
configuration file "httpd.conf", we will now explain
how to set about this.

old
===

...
Options Indexes FollowSymLinks MultiViews

new
===

...
Options FollowSymLinks MultiViews

Simply delete the option "Indexes", and you've solved
the problem!


The .htaccess Method
--------------------
If you are on a system setup without access privilege
to the web server but offering ".htaccess"
functionality, the following entry in your ".htaccess"
file will help you tackle the task:

Options -Indexes

Or, if you have already defined e.g. the Options:

Options +Includes +ExecCGI -Indexes

This rule applies to the directory in which the
".htaccess" is located as well as all subdirectories
below.

In this manner, you can restrict directory display on
your virtual domain, even if the server wide
configuration permits it.

On the reverse side, this will also allow you to enable
directory listing for specific directories, even if the
the server wide configuration does not permit it.

This can be useful in the case of directories featuring
download files.

In this case, your ".htaccess" should have the
following entry:

Options +Indexes


To modify the order in which the files in a given
directory will be displayed, you can use the following
parameters.

In the example below the listing of the main directory
will be sorted:

< http://www.yourdomain.com/?N=A >
Ascending - Sort by file name (default)
< http://www.yourdomain.com/?M=A >
Ascending - Last modification date
< http://www.yourdomain.com/?S=A >
Ascending - Size
< http://www.yourdomain.com/?D=A >
Ascending - Description

< http://www.yourdomain.com/?N=D >
Descending - Sort by file name (default)
< http://www.yourdomain.com/?M=D >
Descending - Last modification date
< http://www.yourdomain.com/?S=D >
Descending - Size
< http://www.yourdomain.com/?D=D >
Descending - Description




This text may freely be republished or distributed in unmodified form provided the following resource box is included intact either at the beginning or the end of the article and a complimentary copy or notice (link) is sent to the author at the address specified below:

Ralph Tegtmeier is the co-founder and principal of fantomaster.com GmbH (Belgium), < http://fantomaster.com/ >, a company specializing in webmasters software development, industrial-strength cloaking and search engine positioning services.

He has been a web marketer since 1994 and is editor-in-chief of fantomNews, a free newsletter focusing on search engine optimization, available at: < http://fantomaster.com/fantomnews-sub.html > You can contact him at mailto:fneditor@fantomaster.com
(c) copyright 2002 by fantomaster.com
All rights reserved.
Downloaded at: < http://fantomaster.com/ >