Access Control

Restricting read and write access to topics and webs, by users and groups

Access Control allows you restrict access to single topics and entire webs, by individual user and by user Groups. Access control, combined with UserAuthentication, lets you easily create and manage an extremely flexible, fine-grained privilege system.

Please note FileAttachments are not protected by Foswiki Access Control in a default configuration (though this can be enabled).

On this page:

An important consideration

Open, freeform editing is the essence of WikiCulture - what makes Foswiki different and often more effective than other collaboration tools. For that reason, it is strongly recommended that the decision to restrict read or write access to a web or a topic is made with great care - the more restrictions, the less Wiki in the mix. Experience shows that unrestricted write access works very well because: As a collaboration guideline, create broad-based Groups (for more and varied input), and avoid creating view-only Users (if you can read it, you should be able to contribute to it).

Permissions settings of the webs on this Foswiki site

The topic SitePermissions gives you an overview of the access control settings for all your webs.

Authentication vs. Access Control

Authentication: Identifies who a user is based on a login procedure. See UserAuthentication.

Access control: Restrict access to content based on users and groups once a user is identified. (Also referred to as Authorization)

Users and groups

Access control is based on the familiar concept of users and groups. Users are defined by their WikiNames. They can then be organized in unlimited combinations by inclusion in one or more user Groups. Groups can also be included in other Groups.

Managing Users

In standard Foswiki a user can create an account in UserRegistration. The following actions are performed: (See ManagingUsers for more details).

The default visitor name is WikiGuest. This is the non-authenticated user. By default the non-authenticated user is not permitted to edit topics. If you require anonymous editing, see "Controlling access to individual scripts" in UserAuthentication.

ALERT! Your local Foswiki may have an alternate user mapping manager installed which doesn't support user registration. Check with your Wiki administrator if you are in doubt.

Managing Groups

The following describes the standard Foswiki support for groups. Your local Foswiki may have an alternate group mapping manager installed. Check with your Wiki administrator if you are in doubt.

Groups are defined by group topics located in the Main web. To create a new group, visit WikiGroups. You will find a "Create a new group" link at the top which reveals a form to create a new group. Enter the name of the new group ending in Group into the "Group Name" form field and the initial members in the "Members" field. This creates a new group topic. (The default User Mapper shipped with Foswiki requires that groups end with the word Group. If your site uses an alternate mapper, it might not have that requirement.)

By default any member of a group has access rights to both adding and removing users from the group through the nice user interface. If you need to limit this access further, change the ALLOWTOPICCHANGE setting through "More Topic Action" -> "Edit topic preference settings".

The ALLOWTOPICCHANGE setting defines who is allowed to change the group topic; it is a comma delimited list of users and groups. You typically want to restrict that to the members of the group itself, so it should contain the name of the topic. This prevents users not in the group from editing the topic to give themselves or others access. For example, for the KasabianGroup topic write:

TIP If you want to hide a group and its list of members, you can set ALLOWTOPICVIEW on the group. For example:

ALERT! Foswiki has strict formatting rules. Settings must be entered as a bullet point.

Background: A group topic is an empty topic with 3 hidden preference settings.

Foswiki 1.1 introduced the smart user interface for adding and removing members of a group. Group topics from prior versions of Foswiki will still work. These have the GROUP setting visible in the topic text itself and you edit it by editing the topic. Foswiki 1.1 WikiGroups will show these old group topics with an "Upgrade Group Topic button". The administrator can upgrade an old group topic to the nice new user interface with one easy click.

The Super Admin Group

A number of Foswiki functions (for example, renaming webs) are only available to administrators. Administrators are simply users who belong to the SuperAdminGroup. This is a standard user group, the name of which is defined by {SuperAdminGroup} setting in configure. The default name of this group is the AdminGroup. The system administrator may have chosen a different name for this group if your local Foswiki uses an alternate group mapping manager, but for simplicity we will use the default name AdminGroup in the rest of this topic.

You can create new administrators simply by adding them to the AdminGroup topic. using the WikiGroups API For example,

A member of the Super Admin Group has unrestricted access throughout the wiki, so only trusted staff should be added to this group.

TIP Hint: Instead of adding users to the AdminGroup, consider adding them to the ALLOWTOPICCHANGE setting for the AdminGroup. Those users will then be able to add and remove themselves from the AdminGroup when they need admin rights, rather than running as admin all the time.

Restricting Access

Access to webs and topics is controlled by:

These preferences have the general form:

permission context mode

Where permission is ALLOW or DENY, context is TOPIC, WEB, or ROOT, and mode is VIEW, CHANGE, or RENAME. For example, the preference ALLOWWEBCHANGE lists who is allowed to change topics in the current web. (Some extensions add additional modes. Ex. ALLOWTOPICCOMMENT.)

And, when enabled by {FeatureAccess} settings:

ALERT! There is an important distinction between CHANGE access and RENAME access. A user can CHANGE a topic, but thanks to version control their changes cannot be lost (the history of the topic before the change is recorded). However if a topic or web is renamed, that history may be lost. Typically a site will only give RENAME access to administrators and content owners.

IDEA! FINALPREFERENCES affects access controls, allowing you to prevent changes to access control settings while still allowing edit access to topics.

Controlling access to a Web

You can define restrictions on who is allowed to view a Foswiki web. You can restrict access to certain webs to selected users and groups, by:

You can also use the asterisk (*) in any of the above settings if you want it to match all possible users.

If your site allows sub-webs, then access to sub-webs is determined from the access controls of the parent web, plus the access controls in the sub-web. So, if the parent web has ALLOWWEBVIEW set, this will also apply to the subweb. Also note that you will need to ensure that the parent web's FINALPREFERENCES does not include the access control settings listed above. Otherwise you will not be able override the parent web's access control settings in sub-webs.

Creation and renaming of sub-webs is controlled by the WEBCHANGE setting on the parent web (or ROOTCHANGE for root webs). Renaming is additionally restricted by the setting of WEBRENAME in the web itself.

Controlling access to a topic

You can also use an asterisk (*) in any of these settings to match all possible users.
ALERT! Caution! Settings are always taken from the latest (current) revision of a topic. If older revisions of a topic had more restrictive access controls, they will not be used when accessing the older revision. If the topic was restricted because it contained sensitive information, and that information was removed, it still exists in the topic history. Once you remove the access restrictions, the topic history will be viewable.

Remember when opening up access to specific topics within a restricted web that other topics in the web - for example, the WebLeftBar - may also need to be accessed when viewing the topics. The message you get when you are denied access should tell you what topic you were not permitted to access.

Access rules in Foswki version 1.x

If your administrator has enabled {AccessControlACL}{EnableDeprecatedEmptyDeny} in the Foswiki configuration then the old behaviour will still work and an empty DENY setting means do not deny anyone the right to access, in other words allow all access.

Click this link to see more documentation on the prior behaviour.
ALERT! If your site started out life using an earlier version of Foswiki, you might have seen that from Foswiki 2.0 onwards, the empty DENY has been removed. This rule has been replaced by * wildcards in the ALLOW and DENY rules.

The previous documentation said:
  • Set ALLOWTOPICVIEW =
    This means the same as not setting it at all.
  • Set DENYTOPICVIEW =
    This means the same as not setting it at all.
As of Foswiki 2.0, the empty DENY setting is now meaningless, unless explicitly overridden by your installation.

  Before Foswiki 2.0 Foswiki 2.0 and newer
Allow ALL users Set DENY to an empty string Set ALLOW to *
Allow All logged-in users

Set DENY to WikiGuest

Leave ALLOW un-set

 <no change from before>
Deny all access Set ALLOW to NobodyGroup

Set ALLOW to NobodyGroup

-or- Set DENY to *
Allow selected users Set ALLOW to desired users/groups Set ALLOW to desired users/groups
Deny selected users Set DENY to desired users/groups Set DENY to desired users/groups

If DENYTOPICVIEW is set to an empty value anyone has access even if ALLOWTOPICVIEW or ALLOWWEBVIEW is defined. This allows you to have very restrictive default access rights to an entire web and still allow individual topics to have more open access.

Wildcard matching

When * is set in a rule, it says that any user identity will match that rule. Setting ALLOW to * says "Allow ALL", setting * to DENY says "Deny ALL".

For example if you want completely open access to a topic for logged in users then use the following rules:

ALERT! Note that it is not possible to override a DENY with an ALLOW at the same level ALLOW on a topic can override DENY at the web level, but not at the TOPIC level

ALERT! If the same setting is defined multiple times the last one overrides the previous. They are not OR'ed together.

ALERT! Setting to an empty value has caused confusion and has been removed. Please read the release notes carefully when you upgrade.

See "How Foswiki evaluates ALLOW/DENY settings" below for more on how ALLOW and DENY interacts.

Controlling access to attachments

Attachments are referred to directly, and are not normally indirected via Foswiki scripts. This means that the above instructions for access control will not apply to attachments. It is possible that someone may inadvertently publicise a URL that they expected to be access-controlled.

The easiest way to apply the same access control rules for attachments as apply to topics is to use the Apache mod_rewrite module, and configure your webserver to redirect accesses to attachments to the Foswiki viewfile script. For example, 

    ScriptAlias /foswiki/bin/ /filesystem/path/to/bin/
    Alias /foswiki/pub/       /filesystem/path/to/pub/

    RewriteEngine on
    RewriteCond %{REQUEST_URI} !^/+foswiki/+pub/+System/+.+
    RewriteRule ^/+foswiki/+pub/+([^/]+)((/+([^/]+))+)/+(.+) /foswiki/bin/viewfile/$1/$2?filename=$5 [L,PT]

That way all the controls that apply to the topic also apply to attachments to the topic. Other types of web servers have similar support.

ALERT! Images embedded in topics will load much slower since each image will be delivered by the viewfile script. The Foswiki:Support.ApacheConfigGenerator has some more extensive examples of protecting user attachments, but allowing direct access to trivial graphics attached to System topics.

Controlling who can manage top-level webs

Top level webs are a special case, because they don't have a parent web with a WebPreferences. So there has to be a special control just for the root level. Note that you do not require ROOTCHANGE access to rename an existing top-level web. You just need WEBCHANGE in the web itself.

How Foswiki evaluates ALLOW/DENY settings

ALERT! Settings are only read from the most current (latest) revision of a topic. Settings from older revisions are never used, even when viewing an older revision with the rdiff script

When deciding whether to grant access, Foswiki evaluates the following rules in order (read from the top of the list; if the logic arrives at PERMITTED or DENIED that applies immediately and no more rules are applied). You need to read the rules bearing in mind that VIEW, CHANGE and RENAME access may be granted/denied separately.

  1. If the user is an administrator
  2. If DENYTOPIC is set to a list of WikiNames, or set to the * wildcard
  3. If ALLOWTOPIC is set to a list of WikiNames, or set to the * wildcard
    1. people in the list are PERMITTED
    2. everyone else is DENIED (nobody is denied if ALLOW is set to *)
  4. If DENYWEB is set to a list of WikiNames, or set to the * wildcard
  5. If ALLOWWEB is set to a list of WikiNames, or set to the * wildcard
  6. If you got this far, access is PERMITTED

Access control and INCLUDE

ALLOWTOPICVIEW and ALLOWTOPICCHANGE only applies to the topic in which the settings are defined. If a topic A includes another topic B, topic A does not inherit the access rights of the included topic B.

Examples: Topic A includes topic B

Access control quick recipes

Obfuscating webs

Another way of hiding webs is by setting the NOSEARCHALL setting in WebPreferences. It does the following: 
   * Set NOSEARCHALL = on

This setup can be useful to hide a new web until content its ready for deployment, or reduce clutter in the WebLeftBar and default search results when restricted access is not desired.

TIP Setting NOSEARCHALL to any value other than the empty string will hide a web. Setting NOSEARCHALL = off will have the same effect as setting it to on

ALERT! Obfuscating a web without setting view access control is very insecure, as anyone who knows the URL can access the web, and explicit searches naming that web will also work. For security purposes it is better to use the ALLOW or DENY VIEW settings in the WebPreferences topic. %SEARCH% and %WEBLIST% will not show any results for webs that the current user does not have permission to view.

Restrict Access to a whole Foswiki site

For a firewalled Foswiki, e.g. an intranet wiki or extranet wiki, you want to allow only invited people to access your Foswiki.
HELP With this configuration, someone with access to the site needs to register new users. ResetPassword will also have to be done by administrators.

When using Apache Login

User authentication with ApacheLogin is enabled on your site. To reqire login for all scripts: 
<FilesMatch ".*">
       require valid-user
</FilesMatch>

If needed, you can further restrict access to selected webs with ALLOWWEBVIEW and other access control settings.

When using Template Login

User authentication with TemplateLogin is enabled on your site. To require login for all scripts: 

{AuthScripts} = 'attach,compareauth,configure,edit,manage,previewauth,rdiffauth,rename,restauth,save,statistics,upload,viewauth,viewfileauth';
{AuthScripts} = 'attach,changes,compare,compareauth,configure,edit,jsonrpc,manage,oops,preview,previewauth,rdiff,rdiffauth,register,rename,resetpasswd,rest,restauth,save,search,statistics,upload,view,viewauth,viewfile,viewfileauth

ALERT! If you install extensions that add scripts, you must also remember to add the new scripts to this list or the new scripts will not be protected.

Authenticate all webs and restrict selected webs

Use the following setup to authenticate users for topic viewing in all webs and to restrict access to selected webs. Requires UserAuthentication to be enabled.

  1. The simple way is to add this to WebPreferences in all webs.
  2. Restrict view access to selected users and groups. Set one or both of these settings in its WebPreferences topic:

In rare cases it may be required to authenticate the view script. This can in some cases have a dramatic performance hit because the webserver must re-authenticate for every page view.

  1. Set require valid-user on your view script in .htaccess or the appropriate Apache .conf file. This looks like: FilesMatch "(attach|edit|manage|rename|save|view|upload|mail|logon|.*auth).*" (normally view is not in that list).

Authenticate and restrict selected webs only

Use the following setup to provide unrestricted viewing access to open webs, with authentication only on selected webs. Requires UserAuthentication to be enabled.

  1. Restrict view access to selected users and groups. Set one or both of these settings in its WebPreferences topic:

Authenticate and restrict most webs, Allow access to selected topics

Use the following setup is used to "lock down" the Wiki to logged in users, while still allowing UserRegistration, ResetPassword, etc. to remain operational. Requires UserAuthentication to be enabled.

  1. Restrict view access by the guest user, and then selectively unlock topics required for normal operation

Control access to topic History and Raw text.

Foswiki 2.0 now restricts the guest user from access to topic history and raw topic text. This is configurable. See: configure Security and Authentication > Access Control > {FeatureAccess}{AllowRaw} and {FeatureAccess}{AllowHistory} (They are expert level settings, so the "Show expert options" button in the lower left corner must be pressed.)

Each of these setting has 3 choices:

When set to acl, then standard DENY and ALLOW processing is performed, RAW and HISTORY are added to the VIEW, CHANGE and RENAME access already described here.

If you want to use ACL level controls, but also want WikiGuest blocked by default, you need to edit every WebPreferences topic and set the following:

Note that these ACL controls block access to the raw= and rev= url parameters. They are not enforced internaly in the "Store". Wiki applications still can access prior revisions, and anyone with CHANGE authority can edit the raw topic text.

Show control settings

You can list the access controls affecting a topic using the %SHOWPREFERENCE{ macro in the topic, thus: 
%SHOWPREFERENCE{"DENYWEBVIEW,ALLOWWEBVIEW,DENYWEBCHANGE,ALLOWWEBCHANGE,DENYWEBRENAME,ALLOWWEBRENAME"}%

For this topic, this displays:

Hide control settings

To hide access control settings from normal browser viewing, you can put them into the topic preference settings by clicking the link Edit topic preference settings under More topic actions menu. Preferences set in this manner are not visible in the topic text, but take effect nevertheless. Access control settings added as topic preference settings are stored in the topic meta data and they override settings defined in the topic text.

Alternatively, place them in HTML comment markers, but this exposes the access setting during ordinary editing. 

<!-- 

 * Set DENYTOPICCHANGE = Main.SomeGroup 

-->

Controlling access to the System web.

Some search engines penalize sites for publishing "duplicate information". The Wiki documentation in the System web falls into that category. Foswiki now has "ALLOWTOPICVIEW = *" settings on critical System topics that require guest access, such as ResetPassword, UserRegistration, and other template topics. You should be able to restrict guest access to the System and retain good operation for guests.

Related Topics: AdminDocumentationCategory, UserAuthentication