NAME¶
Lemonldap::NG::Handler - The Apache protection module part of Lemonldap::NG
Web-SSO system.
SYNOPSIS¶
Create your Apache module¶
Create your own package (example using a central configuration database):
package My::Package;
use Lemonldap::NG::Handler::SharedConf;
@ISA = qw(Lemonldap::NG::Handler::SharedConf);
__PACKAGE__->init ( {
# Local storage used for sessions and configuration
localStorage => "Cache::DBFile",
localStorageOptions => {...},
# How to get my configuration
configStorage => {
type => "DBI",
dbiChain => "DBI:mysql:database=lemondb;host=$hostname",
dbiUser => "lemonldap",
dbiPassword => "password",
}
# Uncomment this to activate status module
# status => 1,
} );
Call your package in /apache-dir/conf/httpd.conf:
# Load your package
PerlRequire /My/File
# TOTAL PROTECTION
PerlHeaderParserHandler My::Package
# OR SELECTED AREA
<Location /protected-area>
PerlHeaderParserHandler My::Package
</Location>
The configuration is loaded only at Apache start. Create an URI to force
configuration reload, so you don't need to restart Apache at each change:
# /apache-dir/conf/httpd.conf
<Location /location/that/I/ve/choosed>
Order deny,allow
Deny from all
Allow from my.manager.com
PerlHeaderParserHandler My::Package->refresh
</Location>
You can also disable access control for specific URIs, but be aware that this is
not really secure, since session cookies are sent to the protected application
(so they could be spoofed), and since a user could forge his own HTTP request
headers and they would not be reset. To disable access control for specific
URIs on a secure way, you should set access rule to 'skip' instead.
<Files "*.gif">
PerlHeaderParserHandler My::Package->unprotect
</Files>
To display the status page, add something like this :
<Location /status>
Order deny,allow
Allow from 10.1.1.0/24
Deny from all
PerlHeaderParserHandler My::Package->status
</Location>
If your application has a "logout" URL, you can configure it directly
in Apache configuration file (or in the manager interface). THIS IS
DEPRECATED, use the manager :
<Location /logout>
PerlHeaderParserHandler My::Package->logout
</Location>
DESCRIPTION¶
Lemonldap::NG is a modular Web-SSO based on Apache::Session modules. It
simplifies the build of a protected area with a few changes in the
application.
It manages both authentication and authorization and provides headers for
accounting. So you can have a full AAA protection for your web space as
described below.
The Apache module part works both with Apache 1.3.x and 2.x ie mod_perl 1 and 2
but
not with mod_perl 1.99.
Authentication, Authorization, Accounting¶
Authentication
If a user isn't authenticated and attempts to connect to an area protected by a
Lemonldap::NG compatible handler, he is redirected to a portal. The portal
authenticates user with a ldap bind by default, but you can also use another
authentication sheme like using x509 user certificates (see
Lemonldap::NG::Portal::AuthSSL for more).
Lemonldap::NG use session cookies generated by Apache::Session so as secure as a
128-bit random cookie. You may use the "securedCookie" options of
Lemonldap::NG::Portal to avoid session hijacking.
You have to manage life of sessions by yourself since Lemonldap::NG knows
nothing about the Apache::Session module you've choosed, but it's very easy
using a simple cron script because Lemonldap::NG::Portal stores the start time
in the "_utime" field. By default, a session stay 10 minutes in the
local storage, so in the worth case, a user is authorized 10 minutes after he
lost his rights.
Authorization
Authorization is controled only by handlers because the portal knows nothing
about the way the user will choose. When configuring your Web-SSO, you have
to:
- •
- choose the ldap attributes you want to use to manage accounting and
authorization (see "exportedHeaders" parameter in
Lemonldap::NG::Portal documentation).
- •
- create Perl expressions to define user groups (using ldap attributes)
- •
- create an array foreach virtual host associating URI regular expressions
and Perl expressions to use to grant access.
Example (See Lemonldap::NG::Manager to see how configuration is stored)
Exported variables (values will be stored in session database by
Lemonldap::NG::Portal):
exportedVars => {
cn => "cn",
departmentUID => "departmentUID",
login => "uid",
},
User groups (values will be stored in session database by
Lemonldap::NG::Portal):
groups => {
group1 => '{ $departmentUID eq "unit1" or $login = "xavier.guimard" }',
...
},
Area protection:
locationRules => {
www1.domain.com => {
'^/protected/.*$' => '$groups =~ /\bgroup1\b/',
default => 'accept',
},
www2.domain.com => {
'^/site/.*$' => '$uid eq "xavier.guimard" or $groups =~ /\bgroup2\b/',
'^/(js|css)' => 'accept',
default => 'deny',
},
},
Performance
You can use Perl expressions as complicated as you want and you can use all the
exported LDAP attributes (and create your own attributes: with 'macros'
mechanism. See Lemonldap::NG::Manager) in groups evaluations, area protections
or custom HTTP headers (you just have to call them with a "$").
You have to be careful when choosing your expressions:
- •
- "groups" and "macros" are evaluated each time a user
is redirected to the portal,
- •
- "locationRules" and "exportedheaders" are evaluated
for each request on a protected area.
It is also recommended to use the "groups" mechanism to avoid having
to evaluate a long expression at each HTTP request:
locationRules => {
www1.domain.com => {
'^/protected/.*$' => '$groups =~ /\bgroup1\b/',
},
},
You can also use LDAP filters, or Perl expression or mixed expressions in
"groups" parameter. Perl expressions has to be enclosed with
"{}":
- •
- "group1 => '(|(uid=xavier.guimard)(ou=unit1))'"
- •
- "group1 => '{$uid eq "xavier.guimard" or $ou eq
"unit1"}'"
- •
- "group1 => '(|(uid=xavier.guimard){$ou eq
"unit1"})'"
It is also recommended to use Perl expressions to avoid requiering the LDAP
server more than 2 times per authentication.
Accounting
Logging portal access
Lemonldap::NG::Portal doesn't log anything by default, but it's easy to overload
"log" method for normal portal access or using "error"
method to know what was wrong if "process" method has failed.
Logging application access
Because an handler knows nothing about the protected application, it can't do
more than logging URL. As Apache does this fine, Lemonldap::NG::Handler gives
it the name to used in logs. The "whatToTrace" parameters indicates
which variable Apache has to use ($uid by default).
The real accounting has to be done by the application itself which knows the
result of SQL transaction for example.
Lemonldap::NG can export HTTP headers either using a proxy or protecting
directly the application. By default, the "Auth-User" field is used
but you can change it using the "exportedHeaders" parameters (stored
in the configuration database). This parameters contains an associative array
per virtual host:
- •
- keys are the names of the chosen headers
- •
- values are Perl expressions where you can use user datas stored in
the global store by calling them "$<varname>".
Example:
exportedHeaders => {
www1.domain.com => {
'Auth-User' => '$uid',
'Unit' => '$ou',
},
www2.domain.com => {
'Authorization' => '"Basic ".encode_base64($employeeNumber.":dummy")',
'Remote-IP' => '$ip',
},
}
Session storage systems¶
Lemonldap::NG use 3 levels of cache for authenticated users:
- •
- an Apache::Session::* module choosed with the "globalStorage"
parameter (completed with "globalStorageOptions") and used by
lemonldap::NG::Portal to store authenticated user parameters,
- •
- a Cache::Cache module choosed with the "localStorage" parameter
(completed with "localStorageOptions") and used to share
authenticated users between Apache's threads or processus and of course
between virtual hosts,
- •
- Lemonldap::NG::Handler variables: if the same user use the same thread or
processus a second time, no request are needed to grant or refuse access.
This is very efficient with HTTP/1.1 Keep-Alive system.
So the number of request to the central storage is limited to 1 per active user
each 10 minutes.
Lemonldap::NG is very fast, but you can increase performance using a
Cache::Cache module that does not use disk access.
Logout system¶
Lemonldap::NG provides a single logout system: you can use it by adding a link
to the portal with "logout=1" parameter in the portal (See
Lemonldap::NG::Portal) and/or by configuring handler to intercept some URL
(See Sinopsys). The logout system:
- •
- delete session in the global session storage,
- •
- replace Lemonldap::NG cookie by '',
- •
- delete handler caches only if logout action was started from a protected
application and only in the current Apache server. So in other servers,
session is still in cache for 10 minutes maximum if the user was connected
on it in the last 10 minutes.
You can also configure rules in the Manager interface to intercept logout URL.
See Lemonldap::NG::Manager and Lemonldap::NG::Handler for more.
USING LEMONLDAP::NG::HANDLER FOR DEVELOPMENT¶
Lemonldap::NG::Handler provides different modules:
- •
- Lemonldap::NG::Handler::Simple: base module. It can be used directly to
protect a single host.
- •
- Lemonldap::NG::Handler::Vhost: module used to managed virtual hosts.
- •
- Lemonldap::NG::Handler::SharedConf: with this module, the configuration
can be centralized. Inherits from Lemonldap::NG::Handler::Vhost and
Lemonldap::NG::Handler::Simple.
- •
- Lemonldap::NG::Handler::CGI: if you have only a few Perl CGI to protect,
you can use this module in your CGI instead of protecting it under
Lemonldap::NG::Handler::SharedConf.
- •
- Lemonldap::NG::Handler::Proxy: this module isn't used to manage security
but is written to create a reverse-proxy without using mod_proxy. In some
case, mod_proxy does not manage correctly some redirections, that is why
this module still exists.
All those modules are compatible both with Apache and mod_perl version 1 and 2,
but NOT with mod_perl 1.99. If you use Linux distributions like Debian Sarge
who provide mod_perl 1.99 for Apache2, you have to use Apache-1.3 or to
download a mod_perl2 backport.
SEE ALSO¶
Lemonldap::NG::Handler::SharedConf, Lemonldap::NG::Portal,
Lemonldap::NG::Manager, <
http://lemonldap-ng.org/>
AUTHOR¶
- Clement Oudot, <clem.oudot@gmail.com>
- Francois-Xavier Deltombe, <fxdeltombe@gmail.com.>
- Xavier Guimard, <x.guimard@free.fr>
BUG REPORT¶
Use OW2 system to report bug or ask for features: <
http://jira.ow2.org>
DOWNLOAD¶
Lemonldap::NG is available at
<
http://forge.objectweb.org/project/showfiles.php?group_id=274>
COPYRIGHT AND LICENSE¶
- Copyright (C) 2006, 2007, 2008, 2009, 2010, 2012 by Xavier Guimard,
<x.guimard@free.fr>
- Copyright (C) 2012 by Francois-Xavier Deltombe,
<fxdeltombe@gmail.com.>
- Copyright (C) 2006, 2009, 2010, 2011, 2012 by Clement Oudot,
<clem.oudot@gmail.com>
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; either version 2, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program. If not, see <
http://www.gnu.org/licenses/>.