PagePermissions user: readonly
Collection:  StFlorian Page:  PagePermissions Last edit:  25/11/09 17:26  by  admin Ver:  1 Hits:  602

Page Permissions

Full recursive ACL page permissions supported (Solaris / Windows style)

Boolean permissions per page and action (granted or denied) based on the current users group membership is implemented with ACL's (Access Control Lists). Opposed to the simplier unix like ugo:rwx system.
The previous system was only based on action and current user, independent of pages.

A individual page permission may be inherited from its parent pages, and from an optional master page ("." or _dotpage').
Use predefined default permissions, if a "." page does not exist.
Pagenames starting with "." have tighter default permissions. (edit, change, list disallowed)

Order of Evaluation (denial overrides granted, or vice versa?)

The array of permissions is evaluated from top to bottom.
Access is granted if the next matching group membership returns true, denied if false.
If the group membership is false, the next group is tried.
If no group membership matches the upper permissions are tried recursively:

current page => basepage => "." page => default perms.

If no group-perm pair grants access, access is denied.

Consider the following perm:

     'change' => array(ACL_ADMIN => false,
                       ACL_OWNER => true));

=> "Members of ADMIN may not change, the owner may change."


For Authentication see WikiUserNew.php, WikiGroup.php and main.php Page Permissions are in PhpWiki since v1.3.9. I suspect ACL page permissions to degrade performance by 10%

Enable/Disable it in config/config.ini
ENABLE_PAGEPERM = true

The defined (and extendable) main.php actions map to simplier access types:

       browse => view
       edit   => edit
       create => edit or create
       remove => remove
       rename => change
       store prefs => change
       list in PageList => list

For simplicity we also map the ACL to the posix-style owner, group and world groups and read, write, execute perms, in cygwin fashion.

Groups - definition of group membership

See WikiGroup how to enable and where to store user-specific group membership. Group methods: database, file, ldap, wikipage, none

ToDo: explain better.

The following special groups are always predefined, even if no other group methods are provided:

  • _EVERY
  • _ANONYMOUS
  • _BOGOUSER
  • _HASHOMEPAGE
  • _SIGNED
  • _AUTHENTICATED
  • _ADMIN
  • _OWNER
  • _CREATOR

Those special groups are stored in a page acl as locale-independent string.

Todo: See the available translations for these special groups.

Other group names are safed as defined by the group methods. (e.g. "Other Users")

Perms - mapping of actions to permissions

PhpWiki supports individual actions, the default is browse. To simplify ACL's these actions are mapped to some special permissions (vulgo 'perms').

We currently support the following permissions which can be stored in every page, for every group.

  • 'list' List this page and all subpages (for PageList)
  • 'view' View this page and all subpages
  • 'edit' Edit this page and all subpages
  • 'create' Create a new (sub)page
  • 'dump' Download the page contents
  • 'change' Change page attributes
  • 'remove' Remove this page

There are no plans to support additional custom perms. The API can handle that, but there's no UI, and it would be only specific for certain plugins, which check permissions by their own.

Action <=> Perm mapping

Those perms are mapped to those actions. ActionPages (plugins) check their access restrictions by themselves.

list
none, 'list' is checked for every pagename listed in PageList, to prevent from being listed in AllPages.
view
browse, viewsource, diff, select, xmlrpc, search, pdf
dump
zip, ziphtml, dumpserial, dumphtml
edit
revert, edit
create
edit or create, if the page doesn't exist yet
change
upload, loadfile, remove, lock, unlock, upgrade, chown, setacl, rename.
all other actionpages which are not wikiwords.

Default Permissions

        $perm = array('view'   => array(ACL_EVERY => true),
                      'edit'   => array(ACL_EVERY => true),
                      'create' => array(ACL_EVERY => true),
                      'list'   => array(ACL_EVERY => true),
                      'remove' => array(ACL_ADMIN => true,
                                        ACL_OWNER => true),
                      'change' => array(ACL_ADMIN => true,
                                        ACL_OWNER => true));
        if (ZIPDUMP_AUTH)
            $perm['dump'] = array(ACL_ADMIN => true,
                                  ACL_OWNER => true);
        else
            $perm['dump'] = array(ACL_EVERY => true);
        // view:
        if (!ALLOW_ANON_USER) {
            if (!ALLOW_USER_PASSWORDS)
                $perm['view'] = array(ACL_SIGNED => true);
            else
                $perm['view'] = array(ACL_AUTHENTICATED => true);
            $perm['view'][ACL_BOGOUSER] = ALLOW_BOGO_LOGIN ? true : false;
        }
        // edit:
        if (!ALLOW_ANON_EDIT) {
            if (!ALLOW_USER_PASSWORDS)
                $perm['edit'] = array(ACL_SIGNED => true);
            else
                $perm['edit'] = array(ACL_AUTHENTICATED => true);
            $perm['edit'][ACL_BOGOUSER] = ALLOW_BOGO_LOGIN ? true : false;
            $perm['create'] = $perm['edit'];
        }
        return $perm;

Source: PhpWikiCvs:lib/PagePerm.php


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