<div>
<ul>
<li><a href="#TWiki Access Control"> TWiki Access Control</a><ul>
- <li><a href="#Users and Groups"> Users and Groups</a></li>
- <li><a href="#Write Access Restriction by Topi"> Write Access Restriction by Topic</a></li>
- <li><a href="#Write Access Restriction by Web"> Write Access Restriction by Web</a></li>
- <li><a href="#Rename Access Restriction by Top"> Rename Access Restriction by Topic</a></li>
- <li><a href="#Rename Access Restriction by Web"> Rename Access Restriction by Web</a></li>
- <li><a href="#Read Access Restriction by Web"> Read Access Restriction by Web</a><ul>
- <li><a href="#Read Access Restriction Notes"> Read Access Restriction Notes</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 Write Access"> Restricting Write Access</a><ul>
+ <li><a href="#Deny Editing by Topic"> Deny Editing by Topic</a></li>
+ <li><a href="#Deny Editing by Web"> Deny Editing by Web</a></li>
+ </ul>
+ </li>
+ <li><a href="#Restricting Rename Access"> Restricting Rename Access</a><ul>
+ <li><a href="#Deny Renaming by Topic"> Deny Renaming by Topic</a></li>
+ <li><a href="#Deny Renaming by Web"> Deny Renaming by Web</a></li>
+ </ul>
+ </li>
+ <li><a href="#Restricting Web Access"> Restricting Web Access</a><ul>
+ <li><a href="#Create Hidden Webs"> Create Hidden Webs</a></li>
+ <li><a href="#Create Authenticated Access By W"> Create Authenticated Access By Web</a></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
-%WIKITOOLNAME% allows you to define restrictions of who is allowed to view a %WIKITOOLNAME% web, make changes to topics or attach files.
+_Restricting read and write access to topics and webs, by users and groups_
-**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:
+[[TWikiAccessControl]] allows you restrict access to single topics and entire webs, by individual user and by user groups, in three main areas: view; edit & attach; and rename/move/delete. These controls, combined with [[TWikiUserAuthentication]], let you easily create and manage an extremely flexible, fine-grained privilege system.
-- There is enough peer pressure to post only conform content.
-- Content does not get lost because topics are under revision control.
-- A topic revision can be undone by a member of the [[TWikiAdminGroup]] in case needed.
+## <a name="An Important Control Considerati"></a> An Important Control Consideration
-### <a name="Users and Groups"></a> Users and Groups
+Open, freeform editing is the essence of the [[WikiCulture]] - it's what makes TWiki different and often more effective than other collaboration tools. So, it is strongly recommended that decisions to restrict read or write access to a web or a topic are made with care. Experience shows that _unrestricted write access_ works very well because:
-Access control is based on users and groups.
+- Peer influence is enough to ensure that only relevant content is posted.
-**_Users_** are defined by the user topics in the Main web, i.e. [[TWikiGuest]]
+- Peer editing - the ability to rearrange anything on a page - keeps topics focussed.
-- Users can be authenticated using basic authentication or SSL. [Installation Notes](TWikiDocumentation#installation) has more.
+- All content is preserved under revision control.
+ - Edits can be undone by the [[TWikiAdminGroup]] (the default administrators group; see #ManagingGroups).
+ - Users are encouraged to edit and refactor (condense a long topic), since there's a safety net.
-**_Groups_** are defined by group topics in the Main web, i.e. [[TWikiAdminGroup]]
+As a collaboration guideline:
-- A group topic name must end in **...Group**
-- The group topic should define these two variables:
- - Set GROUP = < list of users and groups >
- - Set ALLOWTOPICCHANGE = < list of users and groups >
-- GROUP defines the members of the group; it is a comma delimited list of users and other groups. Example: <br />` * Set GROUP = Main.SomeUser, Main.OtherUser, Main.SomeOtherGroup`
-- 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.)
+- Create broad groups (more and varied input), and...
+- Avoid creating view-only users (if you can read it, you can contribute to it).
-### <a name="Write Access Restriction by Topi"></a> Write Access Restriction by Topic
+## <a name="Users and Groups"></a> Users and Groups
-You can define restrictions of who is allowed to make changes to a topic or attach files to it.
+Access control is based on users and groups. Users are defined by their [[WikiNames]], an then organized in unlimited combinations under different user groups.
-Define one or both of these variables in a topic, preferably at the end of the topic:
+### <a name="Managing Users"></a> Managing Users
-- Set DENYTOPICCHANGE = < list of users and groups >
-- Set ALLOWTOPICCHANGE = < list of users and groups >
+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]].
-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`
+- Users can be authenticated using Basic Authentication or SSL. [[TWikiUserAuthentication]] is required in order to track user identities.
-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`
+<a name="ManagingGroups"></a>
-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.
+### <a name="Managing Groups"></a> Managing Groups
-### <a name="Write Access Restriction by Web"></a> Write Access Restriction by Web
+Groups are defined by group topics in the <code>**Main**</code> web, like the [[TWikiAdminGroup]]. To start a new group:
-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.
+1. **Create** a new topic with A name that ends in **Group**, `SomeGroup`
+2. **Define** two variables:
+ - Set GROUP = < list of users and groups >
+ - Set ALLOWTOPICCHANGE = < list of users and groups >
-Define one or both of these variable in the [[WebPreferences]] topic:
+- GROUP is a comma-separated list of users and of other groups:<br /><code>** Set GROUP = Main.SomeUser, Main.OtherUser, Main.SomeOtherGroup**</code>
-- Set DENYWEBCHANGE = < list of users and groups >
-- Set ALLOWWEBCHANGE = < list of users and groups >
+- 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,<br /><code>** Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup**</code><br /> for the TWikiAdminGroup topic. (This prevents users not in the group from editing the topic and from gaining unauthorized membership to the group.)
-The same rules apply like the one for Access Control for Individual Topics; with these additions:
+## <a name="Restricting Write Access"></a> Restricting Write Access
-- DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
-- ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)
+You can define who is allowed to make changes to a web or a topic.
-### <a name="Rename Access Restriction by Top"></a> Rename Access Restriction by Topic
+### <a name="Deny Editing by Topic"></a> Deny Editing by Topic
-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.
+Denying editing of a topic also restricts attaching files to it; both privileges are assigned together.
-Define one or both of these variables in a topic, preferably at the end of the topic:
+- Define one or both of these variables in a topic, preferably at the end of the page:
+ - Set DENYTOPICCHANGE = < list of users and groups >
+ - Set ALLOWTOPICCHANGE = < list of users and groups >
-- Set DENYTOPICRENAME = < list of users and groups >
-- Set ALLOWTOPICRENAME = < list of users and groups >
+- 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`
-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`
+- 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`
-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`
+- 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.
-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 Editing by Web"></a> Deny Editing by Web
-### <a name="Rename Access Restriction by Web"></a> Rename Access Restriction by Web
+Restricting web-level editing blocks creating new topics, changing topics or attaching files.
-You can define restrictions of who is allowed to do renames for a %WIKITOOLNAME% web.
+- Define one or both of these variable in the [[WebPreferences]] topic:
+ - 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:
+The same rules apply as for restricting topics, with these additions:
-- Set DENYWEBRENAME = < list of users and groups >
-- Set ALLOWWEBRENAME = < list of users and groups >
+- DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
+- ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)
-The same rules apply like the one for Access Control for Individual Topics; with these additions:
+## <a name="Restricting Rename Access"></a> Restricting Rename Access
-- DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)
-- ALLOWTOPICRENAME (in topic) overrides ALLOWWEBRENAME (in WebPreferences)
+You can define who is allowed to rename, move or delete a topic, or rename a web.
-### <a name="Read Access Restriction by Web"></a> Read Access Restriction by Web
+### <a name="Deny Renaming by Topic"></a> Deny Renaming by Topic
-You can define restrictions of who is allowed to view a %WIKITOOLNAME% web.
+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.
-Define one or both of these variable in the [[WebPreferences]] topic:
+- Define one or both of these variables in a topic, preferably at the end of the topic:
+ - Set DENYTOPICRENAME = < list of users and groups >
+ - Set ALLOWTOPICRENAME = < list of users and groups >
-- Set DENYWEBVIEW = < list of users and groups >
-- Set ALLOWWEBVIEW = < list of users and groups >
+- 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`
-#### <a name="Read Access Restriction Notes"></a> Read Access Restriction Notes
+- 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`
-- 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](TWikiDocumentation#installation) has more on basic authentication based on the `.htaccess` file.
-- There is a workaround if you prefer to 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 `view` script non authenticated in the `.htaccess` file.
- - Enable the `$doRememberRemoteUser` flag in `wikicfg.pm` as described in [TWiki Authentication](TWikiDocumentation#authentication). %WIKITOOLNAME% will now remember the IP address of an authenticated user.
- - Copy the `view` script to `viewauth` (or better, create a symbolic link)
- - Add `viewauth` to the list of authenticated scripts in the .htaccess file.
- - When a user accesses a web where you enabled view restriction, %WIKITOOLNAME% will redirect from the `view` script to the `viewauth` script once (this hapens only if the user has never edited a topic). Doing so will ask for authentication. The `viewauth` script shows the requested topic if the user could log on and if the user is authorized to see that web.
-- If you enable view restriction for a web, it is recommended to restrict search "all webs" from searching this web. Enable this restriction with the `NOSEARCHALL` variable in its [[WebPreferences]], like:
- - Set NOSEARCHALL = on
-- It is not recommended to restrict view access to individual topics since all content is searchable **_within_** a web.
-- The view restriction is not suitable for very sensitive content since there is a way to circumvent the read access restriction.
+- DENYTOPICRENAME is evaluated before ALLOWTOPICRENAME. Access is denied if the authenticated person is in the DENYTOPICRENAME list, or not in the ALLOWTOPICRENAME list. Access is granted in case DENYTOPICRENAME and ALLOWTOPICRENAME is not defined.
-### <a name="The _SuperAdminGroup"></a> The [[SuperAdminGroup]]
+### <a name="Deny Renaming by Web"></a> Deny Renaming by Web
-The above schema can lock completely a topic in case of a typing error of the ALLOWTOPICCHANGE setting (see [UnchangeableTopicBug](http://www.twiki.org/cgi-bin/view/Codev/UnchangeableTopicBug)). To avoid this:
+You can define restrictions of who is allowed to rename a %WIKITOOLNAME% web.
-- set the `$superAdminGroup` variable in `TWiki.cfg` to the name of a group of users that are always allowed to edit/view topics. E.g.:
+- Define one or both of these variable in the [[WebPreferences]] topic:
+ - Set DENYWEBRENAME = < list of users and groups >
+ - Set ALLOWWEBRENAME = < list of users and groups >
- $superAdminGroup = "TWikiAdminGroup";
+The same rules apply as for topics, with these additions:
-- the default setting is not to have superusers
+- DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)
+- ALLOWTOPICRENAME (in topic) overrides ALLOWWEBRENAME (in WebPreferences)
+
+## <a name="Restricting Web Access"></a> Restricting Web Access
--- [[PeterThoeny]] - 16 Mar 2001 <br /> -- [[AndreaSterbini]] - 11 Apr 2001 <br />
+You can prevent selected users and groups from accessing certain webs, by hiding them using restricting read access, or by requiring login. There are two basic methods, one simple, using standard preferences variables to hide a web, but offering low security, and a secure log-in approach that is currently a workaround, involving some minor script and filesystem modification.
-**_Related topics:_** [[TWikiPreferences]], [[WebPreferences]] (in every web), [[TWikiAdminGroup]], [[TWikiGroups]]
+### <a name="Create Hidden Webs"></a> Create Hidden Webs
+
+You can prevent selected users and groups from viewing certain %WIKITOOLNAME% webs by setting one or both of these variables in each web's [[WebPreferences]] topic:
+
+- - Set DENYWEBVIEW = < list of users and groups >
+ - Set ALLOWWEBVIEW = < list of users and groups >
+- If keeping a hidden web out of general use is a consideration, you should also prevent the "all webs" search option from accessing each hidden web, by enabling the <code>**NOSEARCHALL**</code> variable in [[WebPreferences]]:
+ - Set NOSEARCHALL = on
+ - It is not recommended to restrict view access to individual topics since all content is searchable _within_ a web.
+- %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 with, for example, view-only access for public webs.) [[TWikiInstallationGuide]] has more on Basic Authentication, using the <code>**.htaccess**</code> file.
+- %X% **Hiding 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="Create Authenticated Access By W"></a> Create Authenticated Access By Web
+
+To selectively restrict web access with the security of Basic Authentication, there is a reliable workaround that involves some straightforward code modification:
+
+1. Set aside the <code>**view**</code> script (rename) and create a <code>**view**</code> subdirectory in its place.
+2. In the <code>**view**</code> subdirectory, create a separate copy of a modified viewing script for each web, and create <code>**.htaccess**</code> settings for the restricted webs.
+ - %T% You can use symbolic links to a single copy of the viewing script to make any script updates that much easier.
+
+> **Example of viewing script**
+>
+> <code>**redirect**</code>
+>
+> #!/usr/bin/perl -w
+> #
+>
+> chdir '..';
+>
+> # Adjust SCRIPT and PATH_INFO variables to account for the changed directory
+> my $web = $ENV{SCRIPT_NAME};
+> $web =~ s#^.*/view(/[^/]*).*$#$1#; # isolate the path element after "view"
+> $ENV{PATH_TRANSLATED} =~ s#(/[^/]*)$#$web$1#;
+> $ENV{PATH_INFO} =~ s#(/[^/]*)$#$web$1#;
+> $ENV{SCRIPT_NAME} =~ s#/view$web#/view#;
+> $ENV{SCRIPT_FILENAME} =~ s#/view$web#/view#;
+>
+> # open (LOG, '>>/tmp/redirect.log');
+> # print LOG join ("\n", scalar localtime (time ()), %ENV);
+> # close LOG;
+> exec ('/usr/bin/perl', '-wT', 'view.orig') or
+>
+> print <<EOF;
+> Content-type: text/plain
+>
+> Error executing /cgi-bin/view.orig: $?
+> Click the BACK button in your browser and contact webmaster\@bcs-oops.org.
+>
+> EOF
+
+- **_(Mod by [[ImmoHuneke]] - 16 Mar 2002)_**
+
+**A SECOND OPTION:** A less reliable workaround that also requires code changes is available to provide the same unrestricted viewing access, with authentication required only on selected webs:
+
+1. **Omit** the <code>**view**</code> script from the `.htaccess` file.
+2. **Enable** the <code>**$doRememberRemoteUser**</code> flag in <code>**lib/TWiki.cfg**</code> as described in [[TWikiUserAuthentication]]. %WIKITOOLNAME% will now remember the IP address of an authenticated user. 1. **Copy** the <code>**view**</code> script to <code>**viewauth**</code> (or better, create a symbolic link) 1. **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.
+
+## <a name="Hiding Control Settings"></a> Hiding Control Settings
+
+- %T% To hide access control settings from normal browser viewing, place them in comment markers.
+
+> <!--
+>
+> <br />
+>
+> Set DENYTOPICCHANGE = Main.SomeGroup
+>
+> <br />
+>
+> -->
+
+<a name="SuperAdminGroup"></a>
+
+## <a name="The _SuperAdminGroup"></a> The SuperAdminGroup
+
+By mistyping a user or group name in the ALLOWTOPICCHANGE setting, it's possible to lock a topic so that it no-one can edit it from a browser. To avoid this:
+
+- Set the `$superAdminGroup` variable in `lib/TWiki.cfg` to the name of a group of users that are always allowed to edit/view topics.
+
+> $superAdminGroup = "TWikiAdminGroup";
+
+- The default setting is not to have superusers.
+
+-- [[MikeMannix]] - 20 Mar 2002
git://git.openafs.org / openafs-wiki.git / blobdiff