Protecting Images
There are many things you can do to help keep your cost
of hosting down. One area is to keep your bandwidth usage
to a minimum. Unfortunately, other webmasters do this too
by "hotlinking" to other webmaster's images. What this means
is they use your photos and your bandwidth (by copying your
image location and inserting it into their code), to provide
content for their website. You get charged for the bandwidth
while they get to use your content. Very unethical and a
problem which will continue as long as bandwidth costs money
(which will always be the case).
We have recently setup our Apache webservers to enable the
mod_rewrite feature. For most of you this technical jargin
means nothing. So lets just get on to the meat and potatoes
of this and how it will help you.
How
it works
For many of you who use password protection for your website
in some form or fashion, you will be familiar with the .htaccess
file to some extent. This is used to force the server to
ask for a user name and password. If there is a match in
the password file then the user is allowed access. If not,
they are returned a page indicating their Authentication
failed. Protecting your images will be similar in a way.
By placing the proper .htaccess file into a directory containing
pictures, each time an image is accessed, the server determines
if it is being called from an acceptable location. These
parameters are located within the .htaccess file. If it
is, then the image is displayed. If not, they are redirected
to an html page of your choice, or if the image is a source
tag, the typical icon for an image not found is displayed.
An
example
This is how it works when your site is setup with the mod_rewrite feature.
Here is a breakdown of the structure of the site:
.htaccess
file is located within the images directory
So what happens here. If you go to warning page and enter
the site by normal means, you gain entry. If you try to
go directly into the images directory of the site, you
get redirected back to the warning page. Because the images
directory does not allow access from any location within
itself with the exception of any variation of sirrushosting.net,
access is denied and the surfer is redirected to the warning
page (where they will be able to enter the site properly
and view all the contents of the site). Any domain or site
linking into the personal directory will direct any surfer
going through the link directly to the warning page.
1. The site is protected from hotlinking. Purpose achieved...
2. In addition to protecting the images, the webmaster has
also achieved another goal of forcing all surfers coming
into the site to take a designated path through the site.
This is beneficial force the surfer to view whatever advertising
banners or information the webmaster wants the surfer to
see.
Installation
Installation is rather easy if you have some knowledge of
unix commands. Make edits to the necessary areas of the
file (self explanatory) in the window and then proceed to
the steps below.
1. In the window above, you will change each "RewriteCond"
line to show what domain you are allowing access from. You
can place as many domains or ip addresses here as you would
like to allow access. Please note that if you have users
accessing your page by yourdomain.com as well as www.yourdomain.com,
these will both need to be entered above.
2. Create a file called .htaccess.
Cut and paste the information above into the .htaccess file.
You can either use FTP to upload the file or use telnet
to create the file from scratch. Test the installation out
and you are set.
IMPORTANT:
This feature of the apache webserver is NOT supported by
our technicians. If you have questions about installing
it or would rather have us install it for you (there is
a charge for the labor), please contact tech@sirrushosting.net.
