Writing rules and headers ========================= Lemonldap::NG manages applications by their hostname (Apache's virtualHosts). Rules are used to protect applications, headers are HTTP headers added to the request to give datas to the application (for logs, profiles,...). .. attention:: Note that variables designed by $xx correspond to the name of the :doc:`exported variables` or :ref:`macro names` except for ``$ENV{}`` which correspond to CGI header (``$ENV{REMOTE_ADDR}`` for example). Available $ENV variables ------------------------ The %ENV table provides: - all headers in CGI format (``User-Agent`` becomes ``HTTP_USER_AGENT``) - some CGI variables depending on the context: - For portal: all CGI standard variables (you can add custom headers using ``fastcgi_param`` with Nginx), - For Apache handler: REMOTE_ADDR, QUERY_STRING, REQUEST_URI, SERVER_PORT, REQUEST_METHOD, - For Nginx handler: all variables given by ``fastcgi_param`` commands. - For portal: - $ENV{urldc} : Origin URL before Handler redirection, in cleartext - $ENV{_url} : Origin URL before Handler redirection, base64 encoded See also :doc:`extended functions`. .. _rules: Rules ----- A rule associates a `regular expression `__ to a Perl boolean expression or a keyword. |image0| Examples: =============================================================================================================================================== ================== ====================================== Goal Regular expression Rule =============================================================================================================================================== ================== ====================================== Restrict /admin/ directory to user bart.simpson ^/admin/ Restrict /js/ and /css/ directory to authenticated users ^/(css|js)/ accept Deny access to /config/ directory ^/config/ deny Do not restrict /public/ ^/public/ skip Do not restrict /skip/ and restrict other to authenticated users ^/skip/ $ENV{REQUEST_URI} =~ /skip/ ? skip : 1 Makes authentication optional, but authenticated users are seen as such (that is, user data are sent to the app through HTTP headers) ^/forum/ unprotect Restrict access to the whole site to users that have the LDAP description field set to "LDAP administrator" (must be set in exported variables) default =============================================================================================================================================== ================== ====================================== The "**default**" access rule is used if no other access rule match the current URL. .. tip:: See :doc:`the rules examples page` for a few common use cases .. tip:: - Comments can be used to order your rules: rules are applied in the alphabetical order of comment (or regexp in there is no comment). See :ref:`security chapter` to learn more about writing good rules. - See :ref:`performances` to know how to use macros and groups in rules. Rules can also be used to intercept logout URL: ================================================================================================================= =================== ===================================== Goal Regular expression Rule ================================================================================================================= =================== ===================================== Logout user from Lemonldap::NG and redirect it to http://intranet/ ^/index.php\?logout logout_sso http://intranet/ Logout user from current application and redirect it to the menu **(Apache only)** ^/index.php\?logout logout_app https://auth.example.com/ Logout user from current application and from Lemonldap::NG and redirect it to http://intranet/ **(Apache only)** ^/index.php\?logout logout_app_sso http://intranet/ ================================================================================================================= =================== ===================================== .. danger:: \ ``logout_app`` and ``logout_app_sso`` rules are not available on Nginx, only on Apache. By default, user will be redirected on portal if no URL defined, or on the specified URL if any. .. attention:: Only current application is concerned by logout_app\* targets. Be careful with some applications which doesn't verify Lemonldap::NG headers after having created their own cookies. If so, you can redirect users to a HTML page that explain that it is safe to close browser after disconnect. Rules based on authentication level ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ LLNG set an "authentication level" during authentication process. This level depends on authentication backend used by this user. Default values are: - 0 for :doc:`Null` - 1 for :doc:`CAS`, :doc:`old OpenID-2`, :doc:`Facebook`,… - 2 for web-form based authentication (:doc:`LDAP`, :doc:`DBI`,…) - 3 for :doc:`Yubikey` - 4 for :doc:`Kerberos` - 5 for :doc:`SSL` There are three ways to impose users a higher authentication level: - writing a rule based on authentication level: ``$authenticationLevel > 3`` - set a minimum level in virtual host options (default value for ALL access rules) - a minimum authentication level can be set for each URI access rule. Useful if URI are protected by different types of handler (AuthBasic -> level 2, Main -> level set by authentication backend). .. tip:: Instead of returning a 403 code, "minimum level" returns user to a form that explain that a higher level is required and propose to reauthenticate himself. Using regexp capture in rules ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If URL regexp captures something *(using parenthesis)*, you can use them in the corresponding rule using ``$_rulematch[1]``. Example: only user can access to its personal area: - Regexp: ``/^public_html/(\w+)(/.*)?$`` - Rule: ``$uid eq $_rulematch[1]`` $_rulematch is an array that contains all captured strings. First index is 1. .. warning:: This feature requires Perl ≥ 5.25.7 .. _headers: Headers ------- Headers are associations between an header name and a perl expression that returns a string. Headers are used to give user data to the application. Examples: ============================= ============ ======================= Goal Header name Header value ============================= ============ ======================= Give the uid (for accounting) Auth-User $uid Give a static value Some-Thing "static-value" Give display name Display-Name $givenName." ".$surName Give a non ascii data Display-Name ============================= ============ ======================= As described in :ref:`performances chapter`, you can use macros, local macros,... .. attention:: - Since many HTTP servers refuse non ascii headers, it is recommended to use encode_base64() function to transmit those headers - Don't forget to add an empty string as second argument to encode_base64 function to avoid a "newline" characters insertion in result - Header names must contain only letters and "-" character. With Nginx, you can bypass this restriction by using ``underscores_in_headers on;`` directive .. tip:: By default, SSO cookie is hidden. So protected applications cannot retrieve SSO session key. But you can forward this key if absolutely needed: :: Session-ID => $_session_id Available functions ------------------- In addition to macros and name, you can use some functions in rules and headers: - :doc:`LLNG extended functions` - :doc:`Your custom functions` Wildcards in hostnames ---------------------- Since 2.0, a wildcard can be used in virtualhost name (not in aliases !): ``*.example.com`` matches all hostnames that belong to ``example.com`` domain. Version 2.0.9 improves this and allows better wildcards such as ``test-*.example.com`` or ``test-%.example.com``. The ``%`` wilcard doesn't match subdomains. Even if a wildcard exists, if a virtualhost is explicitly declared, this rule is applied. Example with precedence order for test.sub.example.com: #. test.sub.example.com #. test%.sub.example.com #. test*.sub.example.com #. %.sub.example.com #. \*.sub.example.com #. \*.example.com (``%.example.com`` does not match test.sub.example.com) .. |image0| image:: /documentation/manager-rule.png :class: align-center .. |image1| image:: /documentation/new.png :width: 35px