=head1 NAME

Protecting Your Site

=head1 Description

Securing your site should be your first priority, because of the
consequences a break-in might have. We discuss the various
authentication and authorization techniques available, a very
interesting use of mod_perl.


=head1 The Importance of Your site's Security

Let's face it, your site or service can easily become a target for
Internet "terrorists". It can be because of something you said, the
success of your site, or for no obvious reason whatever. If your site
security is compromised, all your data can be deleted or important
information can be stolen.  You may risk legal action or the sack if
this happens.

Your site can be paralyzed through a _simple_ I<denial of service>
(DoS) attack.

Whatever you do, as long as you are connected to the network your site
will be vulnerable. Cut the connections, turn off your machine and put
it into a safe.  Now it is protected--but useless.

So what can you do?

Let's first get acquainted with some security related terminology:

=over 4

=item Authentication

When you want to make sure that a user is who he claims to be, you
generally ask her for a username and a password. Once you have both,
you can check them against your L<database of username/password
pairs|guide::databases/>.  If they match, the user has passed the
B<Authentication> stage. From now on if you keep the
L<session|guide::modules/Apache__Session___Maintain_session_state_across_HTTP_requests> open all you need to
do is to remember the username.

=item Authorization

You might want to allow user B<foo> to have access to some resource,
but restrict her from accessing another resource, which in turn is
accessible only for user B<bar>. The process of checking access rights
is called B<Authorization>. For B<Authorization> all you need is an
authenticated username or some other attribute which you can authorize
against. For example, you can authorize against IP number, allowing only
your local users to use some service. But be warned that IP numbers or
session_ids can be spoofed (forged), and that is why you should not do
B<Authorization> without B<Authentication>.

=back

Actually you've been familiar with both these concepts for a while.

When you telnet to your account on some machine you go through a login
process (B<Authentication>).

When you try to read some file from your file systems, the kernel
checks the permissions on this file (B<Authorization>). You may hear
about B<Access control> which is another name for the same thing.


=head1 Maintainers

Maintainer is the person(s) you should contact with updates,
corrections and patches.

=over

=item *

Stas Bekman E<lt>stas (at) stason.orgE<gt>

=back


=head1 Authors

=over

=item *

Stas Bekman E<lt>stas (at) stason.orgE<gt>

=back

Only the major authors are listed above. For contributors see the
Changes file.


=cut
