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).
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:
- Peer influence is enough to ensure that only relevant content is posted.
- Peer editing - the ability for anyone to rearrange all content on a page - keeps topics focused.
- In Foswiki, content is transparently preserved under revision control:
- Edits can be undone by the administrator (per default a member of AdminGroup; see AccessControl).
- Users are encouraged to edit and refactor (condense a long topic), since there's a safety net.
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).
- WikiName, encrypted password and email address are recorded using the password manager if authentication is enabled.
- A confirmation e-mail is sent to the user.
- A user home page with the WikiName of the user is created in the Main web.
- The user is added to the WikiUsers topic.
- Optionally the user is added to one or more groups.
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.
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:
-
Set ALLOWTOPICCHANGE = Main.KasabianGroup
- Caution This is set in the "Topic Settings" and not inline in the topic text!
If you want to hide a group and its list of members, you can set
ALLOWTOPICVIEW
on the group. For example:
-
Set ALLOWTOPICVIEW = Main.SecretGroup
- This group will be usable in the ACL of any topic, but is only visible to members of the group.
- Caution As with the the prior example, this is set in the "Topic Settings" and not inline in the topic text!
Foswiki has strict formatting rules. Settings
must be entered as a bullet point.
- With the TML editor, or in the Settings editor, make sure you have three spaces, an asterisk, and an extra space in front of any access control rule.
- When using the WYSIWYG editor, create a bullet using the bullet button on the toolbar.
Background: A group topic is an empty topic with 3 hidden preference settings.
- GROUP: Comma separated list of users and/or groups
- ALLOWTOPICCHANGE: Comma separated list of users and groups that are allowed to add and remove users from the group
- VIEW_TEMPLATE: Always set to the value
GroupView
. This alters the way the topic is presented to include a nice user interface for adding and removing users.
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.
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:
- The
{AuthScripts}
setting in configure -> Security and Authentication -> Login;
- The
{FeatureAccess}
settings in configure -> Security and Authentication -> Access Control; and
- setting the values of certain preferences.
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.)
- Restricting VIEW blocks viewing and searching of content. When you restrict VIEW to a topic or web, this also restricts INCLUDE and Formatted SEARCH from showing the content of the topics.
- Restricting CHANGE blocks creating new topics, changing topics or attaching files.
- Restricting RENAME prevents renaming of topics within a web.
And, when enabled by
{FeatureAccess}
settings:
- Restricting HISTORY blocks access to older revisions of topics by the
rev=
URL parameter.
- Restricting RAW blocks access to the
raw=
topic text.
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.
- Note that ALLOWWEBxxx and DENYWEBxxx preferences can only be set in WebPreferences topics. You cannot define a site level access. Each web must be protected on their own. Subwebs inherit access settings from the parent web. See next section.
- Note that ALLOWTOPICxxx and DENYTOPICxxx preferences apply only to the topic itself.
- Be warned that some plugins may not respect access permissions.
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 GSICS Wiki web. You can restrict access to certain webs to selected users and groups, by:
- authenticating all webs and restricting selected webs: Topic access in all webs is authenticated, and selected webs have restricted access.
- authenticating and restricting selected webs only: Provide unrestricted viewing access to open webs, with authentication and restriction only on selected webs.
- You can define these settings in the WebPreferences topic, preferable towards the end of the topic:
-
Set DENYWEBVIEW = < comma-delimited list of users and groups >
-
Set ALLOWWEBVIEW = < comma-delimited list of users and groups >
-
Set DENYWEBCHANGE = < comma-delimited list of users and groups >
-
Set ALLOWWEBCHANGE = < comma-delimited list of users and groups >
-
Set DENYWEBRENAME = < comma-delimited list of users and groups >
-
Set ALLOWWEBRENAME = < comma-delimited list of users and groups >
- If
{FeatureAccess}{AllowRaw}
is set to acl
in configure, then the following rules are also active:
-
Set ALLOWWEBRAW = < comma-delimited list of users and groups >
-
Set DENYWEBRAW = < comma-delimited list of users and groups >
- If
{FeatureAccess}{AllowHistory}
is set to acl
in configure, then the following rules are also active:
-
Set ALLOWWEBHISTORY = < comma-delimited list of users and groups >
-
Set DENYWEBHISTORY = < comma-delimited list of users and groups >
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 define these settings in any topic, preferable towards the end of the topic:
-
Set DENYTOPICVIEW = < comma-delimited list of users and groups >
-
Set ALLOWTOPICVIEW = < comma-delimited list of users and groups >
-
Set DENYTOPICCHANGE = < comma-delimited list of users and groups >
-
Set ALLOWTOPICCHANGE = < comma-delimited list of users and groups >
-
Set DENYTOPICRENAME = < comma-delimited list of users and groups >
-
Set ALLOWTOPICRENAME = < comma-delimited list of users and groups >
- If
{FeatureAccess}{AllowRaw}
is set to acl
in configure, then the following rules are also active:
-
Set ALLOWTOPICRAW = < comma-delimited list of users and groups >
-
Set DENYTOPICRAW = < comma-delimited list of users and groups >
- If
{FeatureAccess}{AllowHistory}
is set to acl
in configure, then the following rules are also active:
-
Set ALLOWTOPICHISTORY = < comma-delimited list of users and groups >
-
Set DENYTOPICHISTORY = < comma-delimited list of users and groups >
You can also use an asterisk (*) in any of these settings to match all possible users.
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.
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:
-
Set ALLOWTOPICVIEW = *
This allows everyone.
-
Set DENYTOPICVIEW = WikiGuest
This overrides the ALLOW, and denies the guest user.
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
If the same setting is defined multiple times the last one overrides the previous. They are not OR'ed together.
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.
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.
- You can define these settings in the SitePreferences topic, preferably towards the end of the topic:
-
Set DENYROOTCHANGE = < comma-delimited list of users and groups >
-
Set ALLOWROOTCHANGE = < comma-delimited list of users and groups >
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
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.
- If the user is an administrator
- If DENYTOPIC is set to a list of WikiNames, or set to the * wildcard
- people in the list will be DENIED.
- If ALLOWTOPIC is set to a list of WikiNames, or set to the * wildcard
- people in the list are PERMITTED
- everyone else is DENIED (nobody is denied if ALLOW is set to *)
- If DENYWEB is set to a list of WikiNames, or set to the * wildcard
- people in the list are DENIED access (everyone if DENY is set to *)
- If ALLOWWEB is set to a list of WikiNames, or set to the * wildcard
- people in the list will be PERMITTED
- everyone else will be DENIED (nobody is denied if ALLOW is set to *)
- 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
- If the included topic B has ALLOWTOPICCHANGE set to block editing for a user, it does not prevent editing the including topic A.
- If the included topic B has ALLOWTOPICVIEW set to block view for a user, the user can still view topic A but he cannot see the included topic B. He will see a message No permission to view B
Access control quick recipes
Obfuscating webs
Another way of hiding webs is by setting the
NOSEARCHALL
setting in
WebPreferences. It does the following:
- Prevents the
all webs
search option from accessing the web
- Hides the web from the %WEBLIST% macro.
* 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.
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
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.
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:
- lock down access to the whole
bin
and pub
directories to all but valid users. In the Apache .htaccess
file or the appropriate .conf
file, replace the <FilesMatch "(attach|edit|...
section with this:
<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:
- Add all scripts in the
foswiki/bin
directory (except for login
, logon
) to the list of {AuthScripts}
in configure, Security And Authentication
tab, Login
sub-tab, For a default Foswiki installation:
{AuthScripts} = 'attach,compareauth,configure,edit,manage,previewauth,rdiffauth,rename,restauth,save,statistics,upload,viewauth,viewfileauth';
- Restricted (closed) site:
{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
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.
- The simple way is to add this to
WebPreferences
in all webs.
-
Set DENYWEBVIEW = WikiGuest
- Restrict view access to selected users and groups. Set one or both of these settings in its WebPreferences topic:
-
Set ALLOWWEBVIEW = < list of users and groups >
- Note:
DENYWEBVIEW
is evaluated before ALLOWWEBVIEW
. Access is denied if the authenticated person is in the DENYWEBVIEW
list, or not in the ALLOWWEBVIEW
list. Access is granted if DENYWEBVIEW
and ALLOWWEBVIEW
are not defined.
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.
- 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.
- Restrict view access to selected users and groups. Set one or both of these settings in its WebPreferences topic:
-
Set DENYWEBVIEW = < list of users and groups >
-
Set ALLOWWEBVIEW = < list of users and groups >
- Note:
DENYWEBVIEW
is evaluated before ALLOWWEBVIEW
. Access is denied if the authenticated person is in the DENYWEBVIEW
list, or not in the ALLOWWEBVIEW
list. Access is granted if DENYWEBVIEW
and ALLOWWEBVIEW
are not defined.
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.
- Restrict view access by the guest user, and then selectively unlock topics required for normal operation
- Set <nop>DENYWEBVIEW = WikiGuest Set this in each WebPreferences topic:
- Set <nop>ALLOWTOPICVIEW = * Set this in each topic that needs to be unlocked for unauthenticated users.
- Note: ALLOWTOPICVIEW is evaluated before DENYWEBVIEW. Access is permitted if the authenticated person (or wildcard) is in the ALLOWTOPICVIEW list. The list of topics that need to be unlocked in the System web for login, password reset, registration, and guest access when the System has been locked down is rather extensive.
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:
-
authenticated
- This is the default. Anyone who is logged in has access
-
acl
- The feature can be controlled per web or topic using ALLOW or DENY ACLs.
-
all
- Open access like on Foswiki 1.x
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:
- Set DENYWEBVIEW = ""
- Set ALLOWWEBVIEW = ""
- Set DENYWEBCHANGE = ""
- Set ALLOWWEBCHANGE = "%USERSWEB%.AdminGroup"
- ALLOWWEBCHANGE was defined in System.WebPreferences
- Set DENYWEBRENAME = ""
- Set ALLOWWEBRENAME = "%USERSWEB%.AdminGroup"
- ALLOWWEBRENAME was defined in System.WebPreferences
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