view release on metacpan or  search on metacpan

lib/Apache2/AuthCookie.pm  view on Meta::CPAN

 # Use this to make your cookies persistent (+2 hours here)
 PerlSetVar WhatEverExpires +2h

 # Use to make AuthCookie send a P3P header with the cookie
 # see http://www.w3.org/P3P/ for details about what the value 
 # of this should be
 PerlSetVar WhatEverP3P "CP=\"...\""

 # optional: enable decoding of intercepted GET/POST params:
 PerlSetVar WhatEverEncoding UTF-8

 # optional: enable decoding of httpd.conf "Requires" directives
 PerlSetVar WhatEverRequiresEncoding UTF-8

 # optional: enforce that the destination argument from the login form is
 # local to the server
 PerlSetVar WhatEverEnforceLocalDestination 1

 # optional: specify a default destination for when the destination argument
 # of the login form is invalid or unspecified
 PerlSetVar WhatEverDefaultDestination /protected/user/

 # These documents require user to be logged in.
 <Location /protected>
  AuthType Sample::Apache2::AuthCookieHandler
  AuthName WhatEver
  PerlAuthenHandler Sample::Apache2::AuthCookieHandler->authenticate
  PerlAuthzHandler Sample::Apache2::AuthCookieHandler->authorize
  require valid-user
 </Location>

 # These documents don't require logging in, but allow it.
 <FilesMatch "\.ok$">
  AuthType Sample::Apache2::AuthCookieHandler
  AuthName WhatEver
  PerlFixupHandler Sample::Apache2::AuthCookieHandler->recognize_user
 </FilesMatch>

 # This is the action of the login.pl script above.
 <Files LOGIN>
  AuthType Sample::Apache2::AuthCookieHandler
  AuthName WhatEver
  SetHandler perl-script
  PerlResponseHandler Sample::Apache2::AuthCookieHandler->login
 </Files>

=head1 DESCRIPTION

This module is for mod_perl version 2.  If you are running mod_perl version 1,
you should be using B<Apache::AuthCookie> instead.

B<Apache2::AuthCookie> allows you to intercept a user's first
unauthenticated access to a protected document. The user will be
presented with a custom form where they can enter authentication
credentials. The credentials are posted to the server where AuthCookie
verifies them and returns a session key.

The session key is returned to the user's browser as a cookie. As a
cookie, the browser will pass the session key on every subsequent
accesses. AuthCookie will verify the session key and re-authenticate
the user.

All you have to do is write a custom module that inherits from
AuthCookie.  Your module is a class which implements two methods:

=over 4

=item C<authen_cred()>

Verify the user-supplied credentials and return a session key.  The
session key can be any string - often you'll use some string
containing username, timeout info, and any other information you need
to determine access to documents, and append a one-way hash of those
values together with some secret key.

=item C<authen_ses_key()>

Verify the session key (previously generated by C<authen_cred()>,
possibly during a previous request) and return the user ID.  This user
ID will be fed to C<$r-E<gt>user()> to set Apache's idea of who's logged in.

=back

By using AuthCookie versus Apache's built-in AuthBasic you can design
your own authentication system.  There are several benefits.

=over 4

=item 1.

The client doesn't *have* to pass the user credentials on every
subsequent access.  If you're using passwords, this means that the
password can be sent on the first request only, and subsequent
requests don't need to send this (potentially sensitive) information.
This is known as "ticket-based" authentication.

=item 2.

When you determine that the client should stop using the
credentials/session key, the server can tell the client to delete the
cookie.  Letting users "log out" is a notoriously impossible-to-solve
problem of AuthBasic.

=item 3.

AuthBasic dialog boxes are ugly.  You can design your own HTML login
forms when you use AuthCookie.

=item 4.

You can specify the domain of a cookie using PerlSetVar commands.  For
instance, if your AuthName is C<WhatEver>, you can put the command 

 PerlSetVar WhatEverDomain .yourhost.com

into your server setup file and your access cookies will span all
hosts ending in C<.yourhost.com>.

=item 5.

lib/Apache2/AuthCookie.pm  view on Meta::CPAN

=item 3.

You must define a form field called 'destination' that tells
AuthCookie where to redirect the request after successfully logging
in.  Typically this value is obtained from C<$r-E<gt>prev-E<gt>uri>.
See the login.pl script in t/eg/.

=back

In addition, you might want your login page to be able to tell why
the user is being asked to log in.  In other words, if the user sent
bad credentials, then it might be useful to display an error message
saying that the given username or password are invalid.  Also, it
might be useful to determine the difference between a user that sent
an invalid auth cookie, and a user that sent no auth cookie at all.  To
cope with these situations, B<AuthCookie> will set
C<$r-E<gt>subprocess_env('AuthCookieReason')> to one of the following values.

=over 4

=item I<no_cookie>

The user presented no cookie at all.  Typically this means the user is
trying to log in for the first time.

=item I<bad_cookie>

The cookie the user presented is invalid.  Typically this means that the user
is not allowed access to the given page.

=item I<bad_credentials>

The user tried to log in, but the credentials that were passed are invalid.

=back

You can examine this value in your login form by examining
C<$r-E<gt>prev-E<gt>subprocess_env('AuthCookieReason')> (because it's
a sub-request).

Of course, if you want to give more specific information about why
access failed when a cookie is present, your C<authen_ses_key()>
method can set arbitrary entries in C<$r-E<gt>subprocess_env>.

=head1 THE LOGOUT SCRIPT

If you want to let users log themselves out (something that can't be
done using Basic Auth), you need to create a logout script.  For an example,
see t/htdocs/docs/logout.pl.  Logout scripts may want to take advantage of
AuthCookie's C<logout()> method, which will set the proper cookie headers in
order to clear the user's cookie.  This usually looks like
C<$r-E<gt>auth_type-E<gt>logout($r);>.

Note that if you don't necessarily trust your users, you can't count
on cookie deletion for logging out.  You'll have to expire some
server-side login information too.  AuthCookie doesn't do this for
you, you have to handle it yourself.

=head1 ABOUT SESSION KEYS

Unlike the sample AuthCookieHandler, you have you verify the user's
login and password in C<authen_cred()>, then you do something
like:

    my $date = localtime;
    my $ses_key = MD5->hexhash(join(';', $date, $PID, $PAC));

save C<$ses_key> along with the user's login, and return C<$ses_key>.

Now C<authen_ses_key()> looks up the C<$ses_key> passed to it and
returns the saved login.  I use Oracle to store the session key and
retrieve it later, see the ToDo section below for some other ideas.

=head2 TO DO

=over 4

=item *

It might be nice if the logout method could accept some parameters
that could make it easy to redirect the user to another URI, or
whatever.  I'd have to think about the options needed before I
implement anything, though.

=back

=head1 HISTORY

Originally written by Eric Bartley <bartley@purdue.edu>

versions 2.x were written by Ken Williams <ken@forum.swarthmore.edu>

=head1 COPYRIGHT

Copyright (c) 2000 Ken Williams. All rights reserved.

This program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.

=head1 SEE ALSO

L<Apache2::AuthCookie::Base>

=head1 SOURCE

The development version is on github at L<https://github.com/mschout/apache-authcookie>
and may be cloned from L<https://github.com/mschout/apache-authcookie.git>

=head1 BUGS

Please report any bugs or feature requests on the bugtracker website
L<https://github.com/mschout/apache-authcookie/issues>

When submitting a bug or request, please include a test-file or a
patch to an existing test-file that illustrates the bug or desired
feature.

=head1 AUTHOR

Michael Schout <mschout@cpan.org>