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

• GROUP is a comma-separated list of users and of other groups:
      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,
      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.)

Hiding Control Settings

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

<!--
Set DENYTOPICCHANGE = Main.SomeGroup
-->

• • Edits can be undone by the TWikiAdminGroup (the default administrators group; see #ManagingGroups).

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

• Read access restriction only works if the view script is authenticated, that means that users need to log on also just to read topics. TWikiInstallationGuide has more on Basic Authentication based on the .htaccess file.

1. 1. Enable the $doRememberRemoteUser flag in lib/TWiki.cfg as described in TWikiUserAuthentication. netfrag.org will now remember the IP address of an authenticated user.

TWiki Access Control

Overview

An Important Control Consideration

Users and Groups

Managing Users

Managing Groups

Restricting Write Access

Deny Editing by Topic

Deny Editing by Web

Restricting Rename Access

Deny Renaming by Topic

Deny Renaming by Web

Restricting Read Access

Known Issues

Selective Unrestricted Web Access

The SuperAdminGroup

An Important Control Consideration

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:

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

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

As a collaboration guideline:

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

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

1. Create a new topic with A name that ends in Group, SomeGroup
2. Define two variables:

• • GROUP is a comma-separated list of users and of other groups:
        * 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,
        * 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.)

Deny Editing by Topic

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

• 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:
      * Set DENYTOPICCHANGE = 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:
      * 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:

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

• DENYTOPICCRENAME defines users or groups that are not allowed to rename the topic. It is a comma delimited list of users and groups. Example:
      * Set DENYTOPICRENAME = Main.SomeBadBoy, Main.SomeBadGirl, Main.SomeHackerGroup

• ALLOWTOPICRENAME defines users or groups that are allowed to rename the topic. It is a comma delimited list of users and groups. Example:
      * 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:

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

1. 1. Omit the view script from the .htaccess file.
   2. Enable the $doRememberRemoteUser flag in lib/wikicfg.pm as described in User Authentication. netfrag.org will now remember the IP address of an authenticated user.
   3. Copy the view script to viewauth (or better, create a symbolic link)
   4. Add viewauth to the list of authenticated scripts in the .htaccess file.

• 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.
• 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).
  • Editing and refactoring (condensing a long topic) is encouraged (there's a safety net).

Managing Users

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. TWiki Authentication has more.

Managing Groups

• A group topic name must end in _Group

• GROUP defines the members of the group; it is a comma delimited list of users and other groups. Example:
      * Set GROUP = Main.SomeUser, Main.OtherUser, Main.SomeOtherGroup

Restricting Write Access

Deny Editing by Topic

Deny Editing by Web

Restricting Rename Access

Deny Renaming by Topic

Deny Renaming by Web

Restricting Read Access

Known Issues

• 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.

Selective Unrestricted Web Access

• • Leave the view script non-authenticated in the .htaccess file.
  • Enable the $doRememberRemoteUser flag in lib/wikicfg.pm as described in User Authentication. netfrag.org 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:

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

• Set the $superAdminGroup variable in lib/TWiki.cfg to the name of a group of users that are always allowed to edit/view topics.

• The default setting is not to have superusers.

Read Restriction Known Issues

• 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, netfrag.org 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.

The SuperAdminGroup

Write Access Restriction by Topic

Write Access Restriction by Web

Rename Access Restriction by Topic

Rename Access Restriction by Web

Read Access Restriction by Web

Read Access Restriction Notes

The SuperAdminGroup^?

• 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.:

$superAdminGroup = "TWikiAdminGroup";

• the default setting is not to have superusers

-- AndreaSterbini - 11 Apr 2001

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

Rename Access Restriction for Individual Topics

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.

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 >

DENYTOPICCRENAME defines users or groups that are not allowed to rename the topic. It is a comma delimited list of users and groups. Example:
    * Set DENYTOPICRENAME = Main.SomeBadBoy, Main.SomeBadGirl, Main.SomeHackerGroup

ALLOWTOPICRENAME defines users or groups that are allowed to rename the topic. It is a comma delimited list of users and groups. Example:
    * 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.

Rename Access Restriction for a Whole netfrag.org Web

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

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 >

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

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

• • Add viewauth to the list of authenticated scripts in the .htaccess file.

TWiki Access Control

Users and Groups

Write Access Restriction for Individual Topics

Write Access Restriction for a Whole netfrag.org Web

Read Access Restriction for a Whole netfrag.org 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 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. netfrag.org will now remember the IP address of an authenticated user.
  • Copy the view script to viewauth (or better, create a symbolic link)
  • Enable authentication for the viewauth script in the .htaccess file.
  • When a user accesses a web where you enabled view restriction, netfrag.org 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.

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

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

• Set DENYWEBVIEW = < list of users and groups >
• 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.
• The view restriction is not suitable for very sensitive content since there is a way to circumvent the read access restriction.

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

• 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.

IMPORTANT NOTE: Is is recommended to use the access control feature only if absolutely necessary because it goes against the free WikiCulture, where everybody is invited to contribute to any topic.

Users and Groups

Access control is based on users and groups.

Users are defined by the user topics in the Main web, i.e. TWikiGuest^?

• Users can be authenticated using basic authentication or SSL. Installation Notes has more.

Groups are defined by group topics in the Main web, i.e. TWikiAdminGroup

• 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:
      * 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.
      * 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.)

Access Control for Individual Topics

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

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

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

Access Control per netfrag.org Web

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

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

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

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

-- PeterThoeny^? - 28 Oct 2000