• The default setting is not to have superusers.

• 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 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. For convenience, Groups can also be included in other Groups.

Managing Users

Managing Groups

1. Restrict view access to selected Users and Groups. Set one or both of these variables in its WebPreferences topic:
   • Set DENYWEBVIEW = < list of Users and Groups >
   • Set ALLOWWEBVIEW = < list of Users and Groups >

1. Hide the web from an "all webs" search. Enable this restriction with the NOSEARCHALL variable in its WebPreferences topic:
   • Set NOSEARCHALL = on
2. Add view to the list of authenticated scripts in the .htaccess file.

1. Restrict view access to selected Users and Groups. Set one or both of these variables in its WebPreferences topic:
   • Set DENYWEBVIEW = < list of Users and Groups >
   • Set ALLOWWEBVIEW = < list of Users and Groups >

1. Hide the web from an "all webs" search. Enable this restriction with the NOSEARCHALL variable in its WebPreferences topic:
   • Set NOSEARCHALL = on
2. Enable the $doRememberRemoteUser flag in lib/TWiki.cfg as described in TWikiUserAuthentication. TWiki will now remember the IP address of an authenticated user.

Hiding Control Settings

The SuperAdminGroup

• DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)
• ALLOWTOPICRENAME (in topic) overrides ALLOWWEBRENAME (in WebPreferences)

• Set DENYWEBVIEW = < list of Users and Groups >
• Set ALLOWWEBVIEW = < list of Users and Groups >

• Set NOSEARCHALL = on

Use the following setup to provide unrestricted viewing access to open webs, with authentication only on selected webs:

1. Enable the $doRememberRemoteUser flag in lib/TWiki.cfg as described in TWikiUserAuthentication. TWiki will now remember the IP address of an authenticated user.
2. Copy the view script to viewauth (or better, create a symbolic link)

Hiding Control Settings

TWiki Access Control

An Important Control Consideration

• • 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.

Users and Groups

Managing Users

Managing Groups

• • SomeGroup

• • Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup

Restricting Write Access

Denying editing of a topic also restricts file attachment; both privileges are assigned together.

• Define one or both of these variables in a topic, preferably at the end of the page:

• • Set DENYTOPICCHANGE = Main.SomeBadBoy, Main.SomeBadGirl, Main.SomeHackerGroup

• • Set ALLOWTOPICCHANGE = 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.

• Define one or both of these variable in the WebPreferences topic:

The same rules apply as for restricting topics, with these additions:

• DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)

• Define one or both of these variables in a topic, preferably at the end of the topic:

• • Set DENYTOPICRENAME = Main.SomeBadBoy, Main.SomeBadGirl, Main.SomeHackerGroup

• • Set ALLOWTOPICRENAME = Main.SomeGoodGuy, Main.SomeGoodGirl, Main.TWikiAdminGroup

• 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.

• Define one or both of these variable in the WebPreferences topic:

The same rules apply as for topics, with these additions:

• DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)

Restricting Web Access

Create Hidden Webs

If keeping a hidden web out of general use is a consideration, you can prevent the all webs search option from accessing hidden webs, by enabling the NOSEARCHALL 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.

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. (See the next section for a more secure approach.)

• When a user accesses a web where you enabled view restriction, TWiki 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 NOSEARCHALL variable in its WebPreferences, like:
  • Set NOSEARCHALL = on

Hiding Control Settings

• To hide access control settings from normal browser viewing, place them in comment markers.

<!--

The SuperAdminGroup

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:

$superAdminGroup = "TWikiAdminGroup";

• The default setting is not to have superusers.

• Peer editing - the ability to rearrange anything on a page - keeps topics focussed.

• All content is preserved under revision control.

• • Users are encouraged to edit and refactor (condense a long topic), since there's a safety net.

As a collaboration guideline:

Managing Groups

Restricting Write Access

Denying editing of a topic also restricts file attachment; both privileges are assigned together.

• Define one or both of these variables in a topic, preferably at the end of the page:

• 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.

• Define one or both of these variable in the WebPreferences topic:

The same rules apply as for restricting topics, with these additions:

• DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)

• Define one or both of these variables in a topic, preferably at the end of the topic:

• 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.

• Define one or both of these variable in the WebPreferences topic:

The same rules apply as for topics, with these additions:

• DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)

Create Hidden Webs

You can prevent selected users and groups from viewing certain TWiki webs by setting one or both of these variables in each web's WebPreferences topic:

If keeping a hidden web out of general use is a consideration, you can prevent the all webs search option from accessing hidden webs, by enabling the NOSEARCHALL variable in WebPreferences:

• • It is not recommended to restrict view access to individual topics since all content is searchable within a web.
  • This method only works if the view 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 .htaccess file.

Create Authenticated Access By Web

1. Omit the view script from the .htaccess file.
2. Enable the $doRememberRemoteUser flag in lib/TWiki.cfg as described in TWikiUserAuthentication. TWiki will now remember the IP address of an authenticated user.
3. Copy the view script to viewauth (or better, create a symbolic link)

1. Enable the $doRememberRemoteUser flag in lib/TWiki.cfg as described in TWikiUserAuthentication. TWiki will now remember the IP address of an authenticated user.
2. Copy the view script to viewauth (or better, create a symbolic link)
3. Add viewauth to the list of authenticated scripts in the .htaccess file.

• • When a user accesses a web where you enabled view restriction, TWiki 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 NOSEARCHALL variable in its WebPreferences, like:

• • It is not recommended to restrict view access to individual topics since all content is searchable within a web.

Hiding Control Settings

• The default setting is not to have superusers.

Deny Editing by 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 DENYWEBVIEW = < list of users and groups >
  • Set ALLOWWEBVIEW = < list of users and groups >

• • Set NOSEARCHALL = on
  • It is not recommended to restrict view access to individual topics since all content is searchable within a web.

Create Authenticated Access By Web

1. Set aside the view script (rename) and create a view subdirectory in its place.
2. In the view subdirectory, create a separate copy of a modified viewing script for each web, and create .htaccess settings for the restricted webs.
   • You can use symbolic links to a single copy of the viewing script to make any script updates that much easier.

#!/usr/bin/perl -w

1. Omit the view script from the .htaccess file.

• • When a user accesses a web where you enabled view restriction, TWiki 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 NOSEARCHALL variable in its WebPreferences, like:
    • Set NOSEARCHALL = on

The SuperAdminGroup

$superAdminGroup = "TWikiAdminGroup";

• The default setting is not to have superusers.

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

An Important Control Consideration

Users and Groups

Managing Users

• DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)
• ALLOWTOPICRENAME (in topic) overrides ALLOWWEBRENAME (in WebPreferences)

• • Set DENYWEBVIEW = < list of users and groups >
  • Set ALLOWWEBVIEW = < list of users and groups >

1. 1. Omit the view script from the .htaccess file.

• • • When a user accesses a web where you enabled view restriction, TWiki 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 NOSEARCHALL variable in its WebPreferences, like:
      • Set NOSEARCHALL = on

• The default setting is not to have superusers.

Managing Groups

Groups are defined by group topics in the Main web, like the TWikiAdminGroup. To start a new group:

1. Define two variables:
   • Set GROUP = < list of users and groups >
   • Set ALLOWTOPICCHANGE = < list of users and groups >

Restricting Write Access

• • • • Set NOSEARCHALL = on
    • It is not recommended to restrict view access to individual topics since all content is searchable within a web.

The SuperAdminGroup

• The default setting is not to have superusers.

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.

TOC: No TOC in "TWiki.TWikiAccessControl"

Overview

An Important Control Consideration

• Peer influence is enough to ensure that only relevant content is posted.

• Peer editing - the ability to rearrange anything on a page - keeps topics focussed.

• All content is preserved under revision control.

• • Users are encouraged to edit and refactor (condense a long topic), since there's a safety net.

As a collaboration guideline:

Managing Users

Managing Groups

Known Issues

• The view restriction is not suitable for very sensitive content since there is a way to circumvent the read access restriction.

Selective Unrestricted Web Access

• 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:
  1. Omit the view script from the .htaccess file.

1. 1. Copy the view script to viewauth (or better, create a symbolic link)
   2. Add viewauth to the list of authenticated scripts in the .htaccess file.
      • When a user accesses a web where you enabled view restriction, TWiki 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.

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

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.

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:

• Create broad groups (more and varied input), and...
• Avoid creating view-only users (if you can read it, you can contribute to it).

Access control is based on users and groups. Users are defined by their WikiNames, an then organized into unlimited combinations under different user 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.

• Users can be authenticated using Basic Authentication or SSL. Authentication is required in order to track user identities.

Groups are defined by group topics in the Main web, like the TWikiAdminGroup. To start a new group:

1. Create a new topic with A name that ends in Group, SomeGroup

• • 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,
        * Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup
    for the TWikiAdminGroup topic. (This prevents users not in the group from editing the topic and from gaining unauthorized membership to the group.)

You can define who is allowed to make changes to a web or a topic.

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 page:

• 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.

Restricting web-level editing blocks creating new topics, changing topics or attaching files.

• DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
• ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)

You can define who is allowed to rename, move or delete a topic, or rename a 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.

• 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.

You can define restrictions of who is allowed to rename a TWiki web.

• DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)
• ALLOWTOPICRENAME (in topic) overrides ALLOWWEBRENAME (in WebPreferences)

You can define restrictions of who is allowed to view a TWiki web.

• • Set DENYWEBVIEW = < list of users and groups >
  • Set ALLOWWEBVIEW = < list of users and groups >

• 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 has more on Basic Authentication based on the .htaccess file.

• 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:
  1. Omit the view script from the .htaccess file.

• • • It is not recommended to restrict view access to individual topics since all content is searchable within a web.

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.

Overview

• Peer influence is enough to ensure that only relevant content is posted.

• All content is preserved under revision control.
  • Edits can be undone by the TWikiAdminGroup (the default administrators group; see Managing Groups).

Users and Groups

Managing Users

Managing Groups

• • Set GROUP = < list of users and groups >
  • Set ALLOWTOPICCHANGE = < list of users and groups >

Restricting Write Access

• Set DENYTOPICCHANGE = < list of users and groups >
• Set ALLOWTOPICCHANGE = < list of users and groups >

Deny Editing by Web

• Set DENYWEBCHANGE = < list of users and groups >
• Set ALLOWWEBCHANGE = < list of users and groups >

• DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
• ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)

Restricting Rename Access

Deny Renaming by Topic

• Set DENYTOPICRENAME = < list of users and groups >
• Set ALLOWTOPICRENAME = < list of users and groups >

Deny Renaming by Web

• Set DENYWEBRENAME = < list of users and groups >
• Set ALLOWWEBRENAME = < list of users and groups >

• DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)
• ALLOWTOPICRENAME (in topic) overrides ALLOWWEBRENAME (in WebPreferences)

You can define restrictions of who is allowed to view a TWiki web.

• Set DENYWEBVIEW = < list of users and groups >
• Set ALLOWWEBVIEW = < list of users and groups >

Selective Unrestricted Web Access

• 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:

• • When a user accesses a web where you enabled view restriction, TWiki 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 NOSEARCHALL variable in its WebPreferences, like:
  • Set NOSEARCHALL = on

The SuperAdminGroup

$superAdminGroup = "TWikiAdminGroup";

• The default setting is not to have superusers.

-- PeterThoeny - 16 Mar 2001

• • Set NOSEARCHALL = on
• It is not recommended to restrict view access to individual topics since all content is searchable within a web.

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:

TWiki Access Control

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:

Users and Groups

Access control is based on users and groups.

• The group topic should define these two variables:

• • Set GROUP = < list of users and groups >
  • Set ALLOWTOPICCHANGE = < 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, i.e.
      * Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup
  for the TWikiAdminGroup topic. (This is to prevent users not in the group from editing the topic and gaining unauthorized membership to the group.)

You can define restrictions of who is allowed to make changes to a topic or attach files to it.

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 TWiki web. This includes creating new topics, changing topics or attaching files.

• DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
• ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)

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.

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.

You can define restrictions of who is allowed to do renames for a TWiki web.

• DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)
• ALLOWTOPICRENAME (in topic) overrides ALLOWWEBRENAME (in WebPreferences)

You can define restrictions of who is allowed to view a TWiki web.

• Set DENYWEBVIEW = < list of users and groups >
• Set ALLOWWEBVIEW = < list of users and groups >

• The view restriction is not suitable for very sensitive content since there is a way to circumvent the read access restriction.

• 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:

• • When a user accesses a web where you enabled view restriction, TWiki 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.

• • Set NOSEARCHALL = on

The SuperAdminGroup

-- PeterThoeny - 16 Mar 2001
-- AndreaSterbini^? - 11 Apr 2001

• Set DENYWEBVIEW = < list of users and groups >
• Set ALLOWWEBVIEW = < list of users and groups >

• 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 has more on basic authentication based on the .htaccess file.

• • Leave the view script non authenticated in the .htaccess file.
  • Enable the $doRememberRemoteUser flag in wikicfg.pm as described in TWiki Authentication. TWiki 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.

• 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 above schema can lock completely a topic in case of a typing error of the ALLOWTOPICCHANGE setting (see UnchangeableTopicBug). To avoid this:

• 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.:

TWiki Access Control

TWiki allows you to define restrictions of who is allowed to view a TWiki web, make changes to topics or attach files.

• 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.
      * Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup
  for the TWikiAdminGroup topic. (This is to prevent users not in the group from editing the topic and gaining unauthorized membership to the group.)

You can define restrictions of who is allowed to make changes to a topic or attach files to it.

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 TWiki web. This includes creating new topics, changing topics or attaching files.

• DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
• ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)

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.

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.

You can define restrictions of who is allowed to do renames for a TWiki web.

• DENYTOPICRENAME (in topic) overrides DENYWEBRENAME (in WebPreferences)
• ALLOWTOPICRENAME (in topic) overrides ALLOWWEBRENAME (in WebPreferences)

You can define restrictions of who is allowed to view a TWiki web.

• Set DENYWEBVIEW = < list of users and groups >
• Set ALLOWWEBVIEW = < list of users and groups >

• 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 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:

• 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.

The above schema can lock completely a topic in case of a typing error of the ALLOWTOPICCHANGE setting (see UnchangeableTopicBug). To avoid this:

• 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.:

• the default setting is not to have superusers

TWiki Access Control

TWiki allows you to define restrictions of who is allowed to view a TWiki web, make changes to topics or attach files.

• 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.

TWiki Access Control

TWiki allows you to define restrictions of who is allowed to view a TWiki web, make changes to topics or attach files.

• DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
• ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)

Read Access Restriction for a Whole TWiki Web

You can define restrictions of who is allowed to view a TWiki web.

• • Leave the view script non authenticated in the .htaccess file.
  • Enable the $doRememberRemoteUser flag in wikicfg.pm as described in TWiki Authentication. TWiki will now remember the IP address of an authenticated user.
  • Copy the view script to viewauth (or better, create a symbolic link)

• • When a user accesses a web where you enabled view restriction, TWiki 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

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:

• A topic revision can be undone by a member of the TWikiAdminGroup in case needed.

Access control is based on 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, i.e.
      * Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup
  for the TWikiAdminGroup topic. (This is to prevent users not in the group from editing the topic and gaining unauthorized membership to the group.)

You can define restrictions of who is allowed to make changes to a topic or attach files to it.

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 TWiki web. This includes creating new topics, changing topics or attaching files.

• DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
• ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)

You can define restrictions of who is allowed to view a TWiki web.

Related topics: TWikiPreferences, WebPreferences (in every web), TWikiAdminGroup, TWikiGroups

• Set ALLOWWEBVIEW = < list of users and groups >

Notes for 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 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.

• Set ALLOWWEBVIEW = < list of users and groups >

Notes for read access restriction:

• 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.

• 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.

• 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.
      * Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup
  for the TWikiAdminGroup topic. (This is to prevent users not in the group from editing the topic and gaining unauthorized membership to the group.)

Define one or both of these variables in a topic, preferably at the end of the topic:

• Set DENYTOPICCHANGE = < list of users and groups >

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.

Define one or both of these variable in the WebPreferences topic:

• Set DENYWEBCHANGE = < list of users and groups >

• DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
• ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)

You can define some restrictions of who is allowed to make changes and attach files to topics or create new topics in a TWiki web.

• Set DENYWEBCHANGE = < list of users and groups >
• Set ALLOWWEBCHANGE = < list of users and groups >

The same rules apply like the one for Access Control for Individual Topics; with these additions:

-- PeterThoeny - 28 Oct 2000

Users and Groups

• DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
• ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)

-- PeterThoeny - 28 Oct 2000