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.

A user can create an account in TWikiRegistration. The following actions are performed:

• 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.

• WikiName and encrypted password are recorded in .htpasswd if authentication is enabled.
• A confirmation e-mail is sent to the user.
• A user home page with the WikiName of the user is created in the Main web.
• The user is added to the TWikiUsers topic.

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.

The default visitor name is TWikiGuest. This is the non-authenticated user.

• • 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.

• • 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.

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

<!--

• Set DENYTOPICCHANGE = Main.SomeGroup
  -->

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

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

Restricting Web Access

Restricting Read Access

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.

You can define who is allowed to see a web.

Create Hidden Webs

Deny Viewing by Topic

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:

Technically it is possible to restrict read access to an individual topic based on DENYTOPICVIEW / ALLOWTOPICVIEW 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.

Deny Viewing by Web

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

Obfuscate Webs

The idea is to keep a web hidden by not publishing its URL and by preventing the all webs search option from accessing obfuscated webs. Do so by enabling the NOSEARCHALL variable in WebPreferences:

• Set NOSEARCHALL = on

This setup can be useful to hide a new web until content its ready for deployment.

Obfuscating webs is insecure, as anyone who knows the URL can access the web.

Authenticate all Webs and Restrict Selected Webs

Use the following setup to authenticate users for topic viewing in all webs and to restrict access to selected webs:

1. Restrict view access to selected Users and Groups. Set one or both of these variables in its 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:

1. Hide the web from an "all webs" search. Enable this restriction with the NOSEARCHALL variable in its WebPreferences topic:

• • 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.

1. Add view to the list of authenticated scripts in the .htaccess file.

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.)

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

Authenticate and Restricting Selected Webs Only

1. Omit the view script from 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 >
2. Hide the web from an "all webs" search. Enable this restriction with the NOSEARCHALL variable in its WebPreferences topic:
   • Set NOSEARCHALL = on

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

1. Add viewauth to the list of authenticated scripts in the .htaccess file. The view script should not be listed 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.

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.

• 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
• It is not recommended to restrict view access to individual topics since all content is searchable within a web - a search will turn up the "hidden" topic.

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

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.

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.

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:

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

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

• Peer editing - the ability for anyone to rearrange all content on a page - keeps topics focussed.

• All content is preserved under revision control.

• In TWiki, content is transparently preserved under revision control:

As a collaboration guideline:

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).

• 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).

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

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.

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.

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

• 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.

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

1. Start in TWikiGroups and create a new topic with a name that ends in Group. Example:

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

1. Edit TWikiGroups by entering a new topic with a name that ends in Group. Example:

1. Define two variables in the group topic:
   • Set GROUP = < list of users and/or groups >
   • Set ALLOWTOPICCHANGE = < list of users and/or groups >

• A variables is defined as a bullet of format Set NAME = value. A bullet line starts with a multiple of three spaces, an asterisk, and a space.
• The GROUP variable is a comma-separated list of users and/or 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. (This prevents users not in the group from editing the topic and from gaining unauthorized membership to the group.) For example, for the TWikiAdminGroup topic write:

1. Set Preferences for two Variables in the new group topic:
   • Set GROUP = < list of Users and/or Groups >
   • Set ALLOWTOPICCHANGE = < list of Users and/or Groups >
   • The GROUP variable is a comma-separated list of Users and/or other Groups. Example:
     • Set GROUP = Main.SomeUser, Main.OtherUser, Main.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. (This prevents Users not in the Group from editing the topic to give themselves or others access. For example, for the TWikiAdminGroup topic write:

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

• • 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:

• DENYTOPICCHANGE defines Users or Groups that are not allowed to make changes to the topic, with a comma-delimited list. Example:

• 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:

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

• • Set DENYWEBCHANGE = < list of Users and Groups >
  • Set ALLOWWEBCHANGE = < list of Users and Groups >

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

• • 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:

• DENYTOPICCRENAME defines Users or Groups that are not allowed to rename the topic. It is a comma delimited list of Users and Groups. Example:

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

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

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

• • Set DENYWEBRENAME = < list of Users and Groups >
  • Set ALLOWWEBRENAME = < list of Users and Groups >

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.

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.

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:

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

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:

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

• • 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.

• • 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.

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

• It is not recommended to restrict view access to individual topics since all content is searchable within a web - a search will turn up the "hidden" topic.

Set DENYTOPICCHANGE = Main.SomeGroup

• Set DENYTOPICCHANGE = Main.SomeGroup
  

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

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

-- MikeMannix? - 01 Apr 2002
-- PeterThoeny - 04 May 2002

-- PeterThoeny - 04 May 2002
-- MikeMannix? - 12 May 2002

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

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

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

• 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.)

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

1. Start in TWikiGroups and create a new topic with a name that ends in Group. Example:
   • SomeGroup
2. Define two variables in the group topic:
   • Set GROUP = < list of users and/or groups >
   • Set ALLOWTOPICCHANGE = < list of users and/or groups >

• A variables is defined as a bullet of format Set NAME = value. A bullet line starts with a multiple of three spaces, an asterisk, and a space.
• The GROUP variable is a comma-separated list of users and/or 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. (This prevents users not in the group from editing the topic and from gaining unauthorized membership to the group.) For example, for the TWikiAdminGroup topic write:
  • Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup

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

• • 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

• 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

• 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

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

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

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

• • 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

• 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

• 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

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

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

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

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

• Set NOSEARCHALL = on

• Set NOSEARCHALL = on

THIS SECTION CONTAINS WORKAROUNDS. Perhaps unconventional for official documentation, but practical, the following method for extending TWiki functionality involves modifying core TWiki, making it essentially not a feature but a hack. Still, it is officially TWiki developer-approved and documented, and will no doubt be included in some form in an upcoming edition of TWiki.

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 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.

Example of viewing script redirect

#!/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 doesn't involve code changes, but does require renaming a script, can provide the same generally unrestricted viewing access, with authentication only on selected webs:

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

• • • Set NOSEARCHALL = on

• • Set NOSEARCHALL = on

-- MikeMannix? - 01 Apr 2002

-- MikeMannix? - 01 Apr 2002
-- PeterThoeny - 04 May 2002

Denying editing of a topic also restricts attaching files to it; both privileges are assigned together.

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

• 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 NOSEARCHALL variable in WebPreferences:

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:

• 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 with, for example, view-only access for public webs.) TWikiInstallationGuide has more on Basic Authentication, using the .htaccess file.
• 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.

• • 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.

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.)

To selectively restrict web access with the security of Basic Authentication, there is a reliable workaround that involves some straightforward code modification:

THIS SECTION CONTAINS WORKAROUNDS. Perhaps unconventional for official documentation, but practical, the following method for extending TWiki functionality involves modifying core TWiki, making it essentially not a feature but a hack. Still, it is officially TWiki developer-approved and documented, and will no doubt be included in some form in an upcoming edition of TWiki.

To selectively restrict web access with the security of Basic Authentication, there is a reliable workaround that involves some straightforward code modification:

• (Mod by ImmoHuneke? - 16 Mar 2002)

• (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:

A SECOND OPTION: A less reliable workaround that doesn't involve code changes, but does require renaming a script, can provide the same generally unrestricted viewing access, 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. 1. Copy the view script to viewauth (or better, create a symbolic link) 1. Add viewauth to the list of authenticated scripts in the .htaccess file.

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.

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.

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

-- MikeMannix? - 20 Mar 2002

-- MikeMannix? - 01 Apr 2002

Overview

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

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

Restricting Read Access

Restricting Web Access

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

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.

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

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 should also prevent the "all webs" search option from accessing each hidden web, 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.
• 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 with, for example, view-only access for public webs.) TWikiInstallationGuide has more on Basic Authentication, using the .htaccess file.
• 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.

Create Authenticated Access By Web

Known Issues

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 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.

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

Example of viewing script redirect

#!/usr/bin/perl -w
#

Selective Unrestricted Web Access

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)

• 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:

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. 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.

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

-- MikeMannix? - 02 Dec 2001

-- MikeMannix? - 20 Mar 2002

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

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

• 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.)

• 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
-->

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

-- MikeMannix? - 02 Dec 2001

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

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

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

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.

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:

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:

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

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

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.

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.

• 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. TWiki Installation Guide has more on Basic Authentication based on the .htaccess file.

• 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/wikicfg.pm as described in User Authentication. TWiki will now remember the IP address of an authenticated user.

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

TWiki Access Control

TWiki Access Control

Overview

Overview

An Important Control Consideration

An Important Control Consideration

Users and Groups

Users and Groups

Managing Users

Managing Users

Managing Groups

Managing Groups

Restricting Write Access

Restricting Write Access

Deny Editing by Topic

Deny Editing by Topic

Deny Editing by Web

Deny Editing by Web

Restricting Rename Access

Restricting Rename Access

Deny Renaming by Topic

Deny Renaming by Topic

Deny Renaming by Web

Deny Renaming by Web

Restricting Read Access

Restricting Read Access

Known Issues

Known Issues

Selective Unrestricted Web Access

Selective Unrestricted Web Access

The SuperAdminGroup

The SuperAdminGroup

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

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.

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:

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:

• Peer editing - edit anything on a page - keeps topics focussed.

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

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

• • 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).

Access control is based on users and groups.

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. TWiki Authentication has more.

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.

• A group topic name must end in _Group
• The group topic should define these two variables:

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
2. Define two variables:

• 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.)

• • 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

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

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

Deny Editing by Topic

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

• 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

• 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.

• 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.

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

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

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

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:

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.

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 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 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

• 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

• 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.

• 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.

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

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

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

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:

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

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

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

1. 1. Omit the view script from the .htaccess file.
   2. Enable the $doRememberRemoteUser flag in lib/wikicfg.pm as described in User Authentication. TWiki 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.

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:

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

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.

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

Overview

• 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.

• 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).

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.

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

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

• A group topic name must end in ...Group

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

• 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

• 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

Write Access Restriction by Topic

Deny Editing by Topic

Write Access Restriction by Web

Deny Editing by Web

Rename Access Restriction by Topic

Restricting Rename Access

Deny Renaming by Topic

Rename Access Restriction by Web

Deny Renaming by Web

Read Access Restriction by Web

Restricting Read Access

Read Restriction Known Issues

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

• 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 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.