Lemonldap::NG

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.

  1. Authentication, Authorization and Accounting mechanisms
  2. Installation
  3. Session storage system
  4. Logout system
  5. Author
  6. Copyright and licence

  1. Authentication, Authorization and Accounting mechanisms
    1. Authentication
    2. If a user isn't authenticated and attemps 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(3) 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 to avoid session hijacking.

      You have to manage life of sessions by yourself since Lemonldap::NG knows nothing about the L 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.

    3. Authorization
    4. 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:

      Example (See Lemonldap::NG::Manager::Conf(3) to see how configuration is stored) :

      1. Performance
      2. 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) 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,
        • virtual host rules and exported headers are evaluated for each request on a protected area.

        It is also recommanded to use the groups mechanism to avoid having to evaluate a long expression at each HTTP request :

          # Virtual hosts :
              ...
              www1.domain.com :
                  ^/protected/.*$   => $groups =~ /\bgroup1\b/
        

        You can also use LDAP filters, or Perl expression or mixed expressions in groups definitions. 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 recommanded to use Perl expressions to avoid requiering the LDAP server more than 2 times per authentication.

    5. Accounting
      1. Logging portal access
      2. Lemonldap::NG::Portal doesn't log anything by default, but it's easy to overload log method for normal portal access.

      3. Logging application access
      4. Because a Web-SSO knows nothing about the protected application, it can't do more than logging URL. As Apache does this fine, Lemonldap::NG::Handler(3) gives it the name to used in logs. The whatToTrace parameter 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 (in the Manager, each virtual host as custom headers branch). This parameters contains an associative array per virtual host :

        • keys are the names of the choosen headers,
        • values are Perl expressions where you can use user datas stored in the global storage.

        Example:

         * www1.domain.com :
                Auth-User     => $uid
                Unit          => $ou
         * www2.domain.com :
                Authorization => "Basic ".encode_base64($employeeNumber.":dummy")
                Remote-IP     => $ip
        

  2. Installation
  3. Warnings :

    See INSTALL file for a complete installation documentation.

  4. Session storage system
  5. Lemonldap::NG use 3 levels of cache for authenticated users :

    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.

  6. Logout system
  7. 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(3)) and/or by configuring handler to intercept some URL (See Lemonldap::NG::Handler(3)). The logout system:

  8. Author
  9. Xavier Guimard, <x.guimard@free.fr>

  10. Copyright and licence
  11. Copyright © 2005-2007 by Xavier Guimard <x.guimard@free.fr>

    This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.4 or, at your option, any later version of Perl 5 you may have available.