<div>
<ul>
<li><a href="#TWiki Access Control"> TWiki Access Control</a><ul>
- <li><a href="#Overview"> Overview</a></li>
+ <li><a href="#An Important Control Considerati"> An Important Control Consideration</a></li>
<li><a href="#Users and Groups"> Users and Groups</a><ul>
<li><a href="#Managing Users"> Managing Users</a></li>
<li><a href="#Managing Groups"> Managing Groups</a></li>
</ul>
</li>
<li><a href="#Restricting Read Access"> Restricting Read Access</a><ul>
- <li><a href="#Known Issues"> Known Issues</a><ul>
- <li><a href="#Selective Unrestricted Web Acces"> Selective Unrestricted Web Access</a></li>
+ <li><a href="#Deny Viewing by Topic"> Deny Viewing by Topic</a></li>
+ <li><a href="#Deny Viewing by Web"> Deny Viewing by Web</a><ul>
+ <li><a href="#Obfuscate Webs"> Obfuscate Webs</a></li>
+ <li><a href="#Authenticate all Webs and Restri"> Authenticate all Webs and Restrict Selected Webs</a></li>
+ <li><a href="#Authenticate and Restricting Sel"> Authenticate and Restricting Selected Webs Only</a></li>
</ul>
</li>
</ul>
</li>
+ <li><a href="#Hiding Control Settings"> Hiding Control Settings</a></li>
<li><a href="#The _SuperAdminGroup"> The SuperAdminGroup</a></li>
</ul>
</li>
</ul>
</div>
-## <a name="TWiki Access Control"></a> TWiki Access Control
+# <a name="TWiki Access Control"></a> TWiki Access Control
-_Restricting read and write access to topics and webs, by users and groups_
+_Restricting read and write access to topics and webs, by Users and groups_
-### <a name="Overview"></a> Overview
+[[TWikiAccessControl]] allows you restrict access to single topics and entire webs, by individual user and by user Groups, in three areas: view; edit & attach; and rename/move/delete. Access control, combined with [[TWikiUserAuthentication]], lets you easily create and manage an extremely flexible, fine-grained privilege system.
-%WIKITOOLNAME% allows you to define restrictions of who is allowed to view a %WIKITOOLNAME% web, make changes to topics or attach files.
+## <a name="An Important Control Considerati"></a> An Important Control Consideration
-**IMPORTANT NOTE:** Think twice before restricting read or write access to a web or a topic, because an open system where everybody can contribute is the essence of the [[WikiCulture]]. Experience shows that unrestricted write access works very well because:
+Open, freeform editing is the essence of [[WikiCulture]] - what makes TWiki different and often more effective than other collaboration tools. For that reason, it is strongly recommended that decisions to restrict read or write access to a web or a topic are made with 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 - edit anything on a page - keeps topics focussed.
-- All content is preserved under revision control.
- - Edits can be undone by the [[TWikiAdminGroup]] (the default administrators group; see [[Managing Groups|Main/WebHome#ManagingGroups]]).
- - Editing and refactoring (condensing a long topic) is encouraged (there's a safety net).
+- **Peer influence** is enough to ensure that only relevant content is posted.
-### <a name="Users and Groups"></a> Users and Groups
+- **Peer editing** - the ability for anyone to rearrange all content on a page - keeps topics focussed.
-Access control is based on users and groups.
+- In TWiki, content is transparently preserved under **revision control**:
+ - Edits can be undone by the [[TWikiAdminGroup]] (the default administrators group; see [[#ManagingGroups|Main/WebHome#ManagingGroups]]).
+ - Users are encouraged to edit and refactor (condense a long topic), since there's a safety net.
-#### <a name="Managing Users"></a> Managing Users
+As a **collaboration guideline**:
-A user is created by with the TWikiRegistration form. The process generates a topic in the Main web in the new user's [[WikiName]]. The default visitor name is [[TWikiGuest]].
+- 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).
-- Users can be authenticated using Basic Authentication or SSL. [[TWiki Authentication|Main/TWikiDocumentation#TWikiAuthentication]] has more.
+## <a name="Users and Groups"></a> Users and Groups
-<a name="ManagingGroups"></a>
+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. For convenience, Groups can also be included in other Groups.
+
+### <a name="Managing Users"></a> Managing Users
-#### <a name="Managing Groups"></a> Managing Groups
+A user is created with the [[TWikiRegistration]] form. The process generates a topic in the Main web in the new user's [[WikiName]]. The default visitor name is [[TWikiGuest]].
-Groups are defined by group topics in the Main web, like the [[TWikiAdminGroup]].
+- Users can be authenticated using Basic Authentication (htaccess) or SSL (secure server). In either case, [[TWikiUserAuthentication]] is required in order to track user identities, and use User and Group access control.
-- A group topic name must end in **\_Group**
-- The group topic should define these two variables:
+<a name="ManagingGroups"></a>
-> - - Set GROUP = < list of users and groups >
-> - Set ALLOWTOPICCHANGE = < list of users and groups >
+### <a name="Managing Groups"></a> Managing Groups
-- GROUP defines the members of the group; it is a comma delimited list of users and other groups. Example: <br /><code>** \* Set GROUP = Main.SomeUser, Main.OtherUser, Main.SomeOtherGroup**</code>
-- ALLOWTOPICCHANGE 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, i.e. <br />` * Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup`<br /> for the TWikiAdminGroup topic. (This is to prevent users not in the group from editing the topic and gaining unauthorized membership to the group.)
+Groups are defined by group topics created in the <code>**Main**</code> web, like the [[TWikiAdminGroup]]. To create a new group:
-### <a name="Restricting Write Access"></a> Restricting Write Access
+1. <code>**Edit**</code> [[TWikiGroups]] by entering a new topic with a name that ends in <code>**Group**</code>. Example:
+ - <code>**SomeGroup**</code>
+2. **Set Preferences** for two Variables in the new group topic:
+ - <code>**Set GROUP = < list of Users and/or Groups >**</code>
+ - <code>**Set ALLOWTOPICCHANGE = < list of Users and/or Groups >**</code>
+ - The GROUP variable is a comma-separated list of Users and/or other Groups. Example:
+ - <code>**Set GROUP = Main.SomeUser, Main.OtherUser, Main.SomeGroup**</code>
+ - ALLOWTOPICCHANGE 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 TWikiAdminGroup topic write:
+ - <code>**Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup**</code>
-#### <a name="Deny Editing by Topic"></a> Deny Editing by Topic
+## <a name="Restricting Write Access"></a> Restricting Write Access
-You can define restrictions of who is allowed to make changes to a topic or attach files to it.
+You can define who is allowed to make changes to a web or a topic.
-Define one or both of these variables in a topic, preferably at the end of the topic:
+### <a name="Deny Editing by Topic"></a> Deny Editing by Topic
-- Set DENYTOPICCHANGE = < list of users and groups >
-- Set ALLOWTOPICCHANGE = < list of users and groups >
+Denying editing of a topic also restricts file attachment; both privileges are assigned together.
-DENYTOPICCHANGE defines users or groups that **are not** allowed to make changes to the topic. It is a comma delimited list of users and groups. Example: <br />` * Set DENYTOPICCHANGE = Main.SomeBadBoy, Main.SomeBadGirl, Main.SomeHackerGroup`
+- Define one or both of these variables in a topic, preferably at the end of the page:
+ - <code>**Set DENYTOPICCHANGE = < list of Users and Groups >**</code>
+ - <code>**Set ALLOWTOPICCHANGE = < list of Users and Groups >**</code>
-ALLOWTOPICCHANGE defines users or groups that **are** allowed to make changes to the topic. It is a comma delimited list of users and groups. Example: <br />` * Set ALLOWTOPICCHANGE = Main.SomeGoodGuy, Main.SomeGoodGirl, Main.TWikiAdminGroup`
+- DENYTOPICCHANGE defines Users or Groups that **are not** allowed to make changes to the topic, with a comma-delimited list. Example:
+ - <code>**Set DENYTOPICCHANGE = Main.SomeBadBoy, Main.SomeBadGirl, Main.SomeHackerGroup**</code>
-DENYTOPICCHANGE is evaluated before ALLOWTOPICCHANGE. Access is denied if the authenticated person is in the DENYTOPICCHANGE list, or not in the ALLOWTOPICCHANGE list. Access is granted in case DENYTOPICCHANGE and ALLOWTOPICCHANGE is not defined.
+- ALLOWTOPICCHANGE defines Users or Groups that **are** allowed to make changes to the topic. It is a comma delimited list of Users and Groups. Example:
+ - <code>**Set ALLOWTOPICCHANGE = Main.SomeGoodGuy, Main.SomeGoodGirl, Main.TWikiAdminGroup**</code>
-#### <a name="Deny Editing by Web"></a> Deny Editing by Web
+- DENYTOPICCHANGE is evaluated before ALLOWTOPICCHANGE. Access is denied if the authenticated person is in the DENYTOPICCHANGE list, or not in the ALLOWTOPICCHANGE list. Access is granted in case DENYTOPICCHANGE and ALLOWTOPICCHANGE is not defined.
-You can define restrictions of who is allowed to make changes to a %WIKITOOLNAME% web. This includes creating new topics, changing topics or attaching files.
+### <a name="Deny Editing by Web"></a> Deny Editing by Web
-Define one or both of these variable in the [[WebPreferences]] topic:
+Restricting web-level editing blocks creating new topics, changing topics or attaching files.
-- Set DENYWEBCHANGE = < list of users and groups >
-- Set ALLOWWEBCHANGE = < list of users and groups >
+- Define one or both of these variable in the [[WebPreferences]] topic:
+ - <code>**Set DENYWEBCHANGE = < list of Users and Groups >**</code>
+ - <code>**Set ALLOWWEBCHANGE = < list of Users and Groups >**</code>
-The same rules apply like the one for Access Control for Individual Topics; with these additions:
+The same rules apply as for restricting topics, with these additions:
- DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
- ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)
-### <a name="Restricting Rename Access"></a> Restricting Rename Access
+## <a name="Restricting Rename Access"></a> Restricting Rename Access
-#### <a name="Deny Renaming by Topic"></a> Deny Renaming by Topic
+You can define who is allowed to rename, move or delete a topic, or rename a web.
-You can define restrictions of who is allowed to rename a topic. Note that users need this permission in addition to the CHANGE permission in order to rename a topic. They also need CHANGE access to change references in referring topics.
+### <a name="Deny Renaming by Topic"></a> Deny Renaming by Topic
-Define one or both of these variables in a topic, preferably at the end of the topic:
+To allow a user to rename, move or delete a topic, they also need write (editing) permission. They also need write access to change references in referring topics.
-- Set DENYTOPICRENAME = < list of users and groups >
-- Set ALLOWTOPICRENAME = < list of users and groups >
+- Define one or both of these variables in a topic, preferably at the end of the topic:
+ - <code>**Set DENYTOPICRENAME = < list of Users and Groups >**</code>
+ - <code>**Set ALLOWTOPICRENAME = < list of Users and Groups >**</code>
-DENYTOPICCRENAME defines users or groups that **are not** allowed to rename the topic. It is a comma delimited list of users and groups. Example: <br />` * Set DENYTOPICRENAME = Main.SomeBadBoy, Main.SomeBadGirl, Main.SomeHackerGroup`
+- DENYTOPICCRENAME defines Users or Groups that **are not** allowed to rename the topic. It is a comma delimited list of Users and Groups. Example:
+ - <code>**Set DENYTOPICRENAME = Main.SomeBadBoy, Main.SomeBadGirl, Main.SomeHackerGroup**</code>
-ALLOWTOPICRENAME defines users or groups that **are** allowed to rename the topic. It is a comma delimited list of users and groups. Example: <br />` * Set ALLOWTOPICRENAME = Main.SomeGoodGuy, Main.SomeGoodGirl, Main.TWikiAdminGroup`
+- ALLOWTOPICRENAME defines Users or Groups that **are** allowed to rename the topic. It is a comma delimited list of Users and Groups. Example:
+ - <code>**Set ALLOWTOPICRENAME = Main.SomeGoodGuy, Main.SomeGoodGirl, Main.TWikiAdminGroup**</code>
-DENYTOPICRENAME is evaluated before ALLOWTOPICRENAME. Access is denied if the authenticated person is in the DENYTOPICRENAME list, or not in the ALLOWTOPICRENAME list. Access is granted in case DENYTOPICRENAME and ALLOWTOPICRENAME is not defined.
+- DENYTOPICRENAME is evaluated before ALLOWTOPICRENAME. Access is denied if the authenticated person is in the DENYTOPICRENAME list, or not in the ALLOWTOPICRENAME list. Access is granted in case DENYTOPICRENAME and ALLOWTOPICRENAME is not defined.
-#### <a name="Deny Renaming by Web"></a> Deny Renaming by Web
+### <a name="Deny Renaming by Web"></a> Deny Renaming by Web
-You can define restrictions of who is allowed to do renames for a %WIKITOOLNAME% web.
+You can define restrictions of who is allowed to rename a %WIKITOOLNAME% web.
-Define one or both of these variable in the [[WebPreferences]] topic:
+- Define one or both of these variable in the [[WebPreferences]] topic:
+ - <code>**Set DENYWEBRENAME = < list of Users and Groups >**</code>
+ - <code>**Set ALLOWWEBRENAME = < list of Users and Groups >**</code>
-- Set DENYWEBRENAME = < list of users and groups >
-- Set ALLOWWEBRENAME = < list of users and groups >
-
-The same rules apply like the one for Access Control for Individual Topics; with these additions:
+The same rules apply as for topics, with these additions:
- DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)
- ALLOWTOPICRENAME (in topic) overrides ALLOWWEBRENAME (in WebPreferences)
-### <a name="Restricting Read Access"></a> Restricting Read Access
+## <a name="Restricting Read Access"></a> Restricting Read Access
+
+You can define who is allowed to see a web.
+
+### <a name="Deny Viewing by Topic"></a> Deny Viewing by Topic
+
+%X% Technically it is possible to restrict read access to an individual topic based on <code>**DENYTOPICVIEW**</code> / <code>**ALLOWTOPICVIEW**</code> preferences variables, provided that the view script is authenticated. However this setup is not recommended since all content is searchable within a web - a search will turn up view restricted topics.
+
+### <a name="Deny Viewing by Web"></a> Deny Viewing by Web
+
+You can define restrictions of who is allowed to view a %WIKITOOLNAME% web. You can restrict access to certain webs to selected Users and Groups, by:
+
+- **obfuscating webs:** Insecure but handy method to hide new webs until content is ready for deployment.
+- **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.
+
+#### <a name="Obfuscate Webs"></a> Obfuscate Webs
-You can define restrictions of who is allowed to view a %WIKITOOLNAME% web.
+The idea is to keep a web hidden by not publishing its URL and by preventing the <code>**all webs**</code> search option from accessing obfuscated webs. Do so by enabling the <code>**NOSEARCHALL**</code> variable in [[WebPreferences]]:
-Define one or both of these variable in the [[WebPreferences]] topic:
+- <code>**Set NOSEARCHALL = on**</code>
-- Set DENYWEBVIEW = < list of users and groups >
-- Set ALLOWWEBVIEW = < list of users and groups >
+This setup can be useful to hide a new web until content its ready for deployment.
-#### <a name="Known Issues"></a> Known Issues
+%X% **Obfuscating webs is insecure**, as anyone who knows the URL can access the web.
-- The view restriction is not suitable for very sensitive content since there is a way to circumvent the read access restriction.
-- Read access restriction only works if the view script is authenticated, that means that users need to log on also just to read topics. [[TWiki Installation Guide|Main/TWikiDocumentation#TWikiInstallationGuide]] has more on Basic Authentication based on the <code>**.htaccess**</code> file.
+#### <a name="Authenticate all Webs and Restri"></a> Authenticate all Webs and Restrict Selected Webs
-##### <a name="Selective Unrestricted Web Acces"></a> Selective Unrestricted Web Access
+Use the following setup to authenticate users for topic viewing in all webs and to restrict access to selected webs:
-- There is a workaround if you prefer to have unrestricted access to view topics located in normal webs, and to authenticate users only for webs where view restriction is enabled:
- - Leave the <code>**view**</code> script non-authenticated in the `.htaccess` file.
- - Enable the <code>**$doRememberRemoteUser**</code> flag in <code>**lib/wikicfg.pm**</code> as described in [[User Authentication|Main/TWikiDocumentation#TWikiUserAuthentication]]. %WIKITOOLNAME% will now remember the IP address of an authenticated user.
- - Copy the <code>**view**</code> script to <code>**viewauth**</code> (or better, create a symbolic link)
- - Add <code>**viewauth**</code> to the list of authenticated scripts in the .htaccess file.
- - When a user accesses a web where you enabled view restriction, %WIKITOOLNAME% will redirect from the `view` script to the `viewauth` script once (this happens only if the user has never edited a topic). Doing so will ask for authentication. The `viewauth` script shows the requested topic if the user could log on and if the user is authorized to see that web.
-- If you enable view restriction for a web, it is recommended to restrict search "all webs" from searching this web. Enable this restriction with the <code>**NOSEARCHALL**</code> variable in its [[WebPreferences]], like:
- - Set NOSEARCHALL = on
-- It is not recommended to restrict view access to individual topics since all content is searchable _within_ a web.
+1. **Restrict** view access to selected Users and Groups. Set one or both of these variables in its [[WebPreferences]] topic:
+ - <code>**Set DENYWEBVIEW = < list of Users and Groups >**</code>
+ - <code>**Set ALLOWWEBVIEW = < list of Users and Groups >**</code>
+ - **_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 in case `DENYWEBVIEW` and `ALLOWWEBVIEW` is not defined.
+2. **Hide** the web from an "all webs" search. Enable this restriction with the <code>**NOSEARCHALL**</code> variable in its [[WebPreferences]] topic:
+ - <code>**Set NOSEARCHALL = on**</code>
+3. **Add** <code>**view**</code> to the list of authenticated scripts in the `.htaccess` file.
+
+%H% This method only works if the <code>**view**</code> script is authenticated, which means that all Users have to login, even for read-only access. (An open guest account, like [[TWikiGuest]], can get around this, allowing anyone to login to a common account with, for example, view-only access for public webs.) [[TWikiInstallationGuide]] has more on Basic Authentication, using the <code>**.htaccess**</code> file.
+
+#### <a name="Authenticate and Restricting Sel"></a> Authenticate and Restricting Selected Webs Only
+
+Use the following setup to provide unrestricted viewing access to open webs, with authentication only on selected webs:
+
+1. **Restrict** view access to selected Users and Groups. Set one or both of these variables in its [[WebPreferences]] topic:
+ - <code>**Set DENYWEBVIEW = < list of Users and Groups >**</code>
+ - <code>**Set ALLOWWEBVIEW = < list of Users and Groups >**</code>
+ - **_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 in case `DENYWEBVIEW` and `ALLOWWEBVIEW` is not defined.
+2. **Hide** the web from an "all webs" search. Enable this restriction with the <code>**NOSEARCHALL**</code> variable in its [[WebPreferences]] topic:
+ - <code>**Set NOSEARCHALL = on**</code>
+3. **Enable** the <code>**$doRememberRemoteUser**</code> flag in <code>**lib/TWiki.cfg**</code> as described in [[TWikiUserAuthentication]]. %WIKITOOLNAME% will now remember the IP address of an authenticated user.
+4. **Copy** the <code>**view**</code> script to <code>**viewauth**</code> (or better, create a symbolic link)
+5. **Add** <code>**viewauth**</code> to the list of authenticated scripts in the `.htaccess` file. The <code>**view**</code> script should not be listed in the `.htaccess` file.
+
+When a user accesses a web where you enabled view restriction, %WIKITOOLNAME% will redirect from the `view` script to the `viewauth` script once (this happens only if the user has never edited a topic). Doing so will ask for authentication. The `viewauth` script shows the requested topic if the user could log on and if the user is authorized to see that web.
+
+%X% **Authenticating webs is not very secure**, as there is a way to circumvent the read access restriction. It can be useful in certain situations - for example, to simplify site organization and clutter, by hiding low traffic webs - but is not recommended for securing sensitive content.
+
+## <a name="Hiding Control Settings"></a> Hiding Control Settings
+
+%T% To hide access control settings from normal browser viewing, place them in comment markers.
+
+<style="background-color:#f5f5f5"> `<!--`<br />` * Set DENYTOPICCHANGE = Main.SomeGroup`<br />`-->`
<a name="SuperAdminGroup"></a>
-### <a name="The _SuperAdminGroup"></a> The SuperAdminGroup
+## <a name="The _SuperAdminGroup"></a> The SuperAdminGroup
-The above schema can lock completely a topic in case of a typing error of the ALLOWTOPICCHANGE setting (see [[UnchangeableTopicBug]] for more detail). To avoid this:
+By mistyping a user or group name in the ALLOWTOPICCHANGE setting, it's possible to lock a topic so that no-one can edit it from a browser. To avoid this, you can create Web-based **superusers**:
-- Set the <code>**$superAdminGroup**</code> variable in <code>**lib/TWiki.cfg**</code> to the name of a group of users that are always allowed to edit/view topics.
+- Set the <code>**$superAdminGroup**</code> variable in <code>**lib/TWiki.cfg**</code> to the name of a group of Users who are always allowed to edit/view topics.
- $superAdminGroup = "TWikiAdminGroup";
+> $superAdminGroup = "TWikiAdminGroup";
- The default setting is not to have superusers.
--- [[PeterThoeny]] - 16 Mar 2001 <br /> -- [[AndreaSterbini]] - 11 Apr 2001 <br />
-
-**_Related topics:_** [[TWikiPreferences]], [[WebPreferences]] (in every web), [[TWikiAdminGroup]], [[TWikiGroups]]
+-- [[PeterThoeny]] - 04 May 2002<br /> -- [[MikeMannix]] - 12 May 2002
git://git.openafs.org / openafs-wiki.git / blobdiff