Securing File Attachments

The preferred method to secure attachments is by editing the twiki.conf file to include:

• You can use TWiki:TWiki/ApacheConfigGenerator to generate the Apache config file for TWiki.
• You will need to restart your Apache server after this change.
• Images embedded in topics will load slower since attached images will also be delivered by the viewfile script. The TWiki web and Sandbox web are excluded for performance reasons.
• As an alternative to editing the twiki.conf file used by Apache, you can make the same change directly to the .htaccess file in the /twiki/bin directory.
• The viewfile script sets the mime type based upon file name suffix. Unknown types are served as text/plain which can result in corrupt files.

The setting to an empty has caused confusion and great debate and it has been decided that the empty setting syntax will be replaced by something which is easier to understand in a later version of TWiki. A method to upgrade will be provided. Please read the release notes carefully when you upgrade.

Access control and INCLUDE

ALLOWTOPICVIEW and ALLOWTOPICCHANGE only applies to the topic in which the settings are defined. If a topic A includes another topic B, topic A does not inherit the access rights of the included topic B.

Examples: Topic A includes topic B

• If the included topic B has ALLOWTOPICCHANGE set to block editing for a user, it does not prevent editing the including topic A.
• If the included topic B has ALLOWTOPICVIEW set to block view for a user, the user can still view topic A but he cannot see the included topic B. He will see a message No permission to view B

TWiki Access Control

• • Edits can be undone by the administrator (per default a member of TWikiAdminGroup; see #ManagingGroups).

• A user home page with the WikiName of the user is created in the Main web.
• The user is added to the TWikiUsers topic.

• Set GROUP = Main.SomeUser, Main.OtherUser, Main.SomeGroup

• Set ALLOWTOPICCHANGE = Main.KasabianGroup

• Set GROUP = Main.ElizabethWindsor, Main.TonyBlair

• Restricting VIEW blocks viewing and searching of content. When you restric VIEW to a topic or web, this also restricts INCLUDE and Formatted SEARCH from showing the content of the topics.

• • Set ALLOWWEBCHANGE = TWikiAdminGroup, TWikiRegistrationAgent

• You can define these settings in the Main.%TWIKIPREFSTOPIC% topic, preferable towards the end of the topic:

Restrict Access to Whole TWiki Site

For a firewalled TWiki, e.g. an intranet wiki or extranet wiki, you want to allow only invited people to access your TWiki. In this case, enable user authentication with ApacheLogin and lock down access to the whole twiki/bin and twiki/pub directories to all but valid users. In the Apache .htaccess file or the appropriate .conf file, replace the <FilesMatch "(attach|edit|... section with this:

<FilesMatch ".*">
       require valid-user
</FilesMatch>

If needed, you can further restrict access to selected webs with ALLOWWEBVIEW and other access control settings.

Note: With this configuration, someone with access to the site needs to register new users.

1. Set require valid-user on your view script in .htaccess or the appropriate Apache .conf file. As of 4.x, this looks like: FilesMatch "(attach|edit|manage|rename|save|view|upload|mail|logon|.*auth).*" (normally view is not in that list).

• • 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 if DENYWEBVIEW and ALLOWWEBVIEW are not defined.

1. If you still want public users to be able to register automatically follow TWiki:TWiki.RegisterOnViewRestrictedSite.

• • 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 if DENYWEBVIEW and ALLOWWEBVIEW are not defined.

• • Edits can be undone by the administrator (per default a member of TWikiAdminGroup; see #ManagingGroups).

Groups are defined by group topics located in the Main web. To create a new group, visit TWikiGroups and enter the name of the new group ending in Group into the "new group" form field. This will create a new group topic with two important settings:

• Set ALLOWTOPICCHANGE = Main.KasabianGroup

You can create new administrators simply by adding them to the TWikiAdminGroup topic. For example,

• Restricting RENAME prevents renaming of topics within a web.

Note that there is an important distinction between CHANGE access and RENAME access. A user can CHANGE a topic, but thanks to version control their changes cannot be lost (the history of the topic before the change is recorded). However if a topic or web is renamed, that history may be lost. Typically a site will only give RENAME access to administrators and content owners.

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

Creation and renaming of sub-webs is controlled by the WEBCHANGE setting on the parent web (or ROOTCHANGE for root webs). Renaming is additionally restricted by the setting of WEBRENAME in the web itself.

Note: For Web level access rights Setting any of these settings to an empty value has the same effect as not setting them at all. Please note that the documentation of TWiki 4.0 and earlier versions of TWiki 4.1 did not reflect the actual implementation, e.g. an empty ALLOWWEBVIEW does not prevent anyone from viewing the web, and an an empty DENYWEBVIEW does not allow all to view the web.

• • Set DENYTOPICRENAME = < comma-delimited list of Users and Groups >
  • Set ALLOWTOPICRENAME = < comma-delimited list of Users and Groups >

• Set ALLOWTOPICVIEW =
  This means the same as not setting it at all. (This was documented wrong in versions 4.0.X, 4.1.0 and 4.1.1)

• Set DENYTOPICVIEW =
  Since TWiki 4.0 this means do not deny anyone the right to view this topic. If DENYTOPICVIEW is set to an empty value anyone has access even if ALLOWTOPICVIEW or ALLOWWEBVIEW is defined. This allows to have very restrictive default access rights to an entire web and still allow individual topics to have more open access.

The same rules apply to ALLOWTOPICCHANGE/DENYTOPICCHANGE and APPLYTOPICRENAME/DENYTOPICRENAME. Setting ALLOWTOPICCHANGE or ALLOWTOPICRENAME to en empty value means the same as not defining it. Setting DENYTOPICCHANGE or DENYTOPICRENAME to an empty value means that anyone can edit or rename the topic.

The setting to an empty has caused confusion and great debate and it has been decided that the empty setting syntax will be replaced by something which is easier to understand in the 4.2 version of TWiki. A method to upgrade will be provided. Please read the release notes carefully when you upgrade.

See "How TWiki evaluates ALLOW/DENY settings" below for more on how ALLOW and DENY interacts.

Controlling who can manage top-level webs

1. If the user is an administrator

• • access is PERMITTED i.e no-one is denied access to this topic.
    Attention: Use this with caution. This is deprecated and will likely change in the next release.

1. If DENYWEB is set to a list of wikinames

• You can define these settings in any topic, preferable towards the end of the topic:

Controlling who can create top-level webs

• You can define these settings in the Main.%TWIKIPREFSTOPIC% topic, preferable towards the end of the topic:
  • Set DENYROOTCHANGE = < comma-delimited list of Users and Groups >
  • Set ALLOWROOTCHANGE = < comma-delimited list of Users and Groups >

Tip:

Alternatively, place them in HTML comment markers, but this exposes the access setting during ordinary editing.

An Important Control Consideration

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

Permissions settings of the webs on this TWiki site

Web	Sitemap	VIEW		CHANGE		RENAME
	Listed	DENY	ALLOW	DENY	ALLOW	DENY	ALLOW
Main	on
TWiki	on						TWikiAdminGroup
Sandbox	on

Please Note:

• A blank in the the above table may mean either the corresponding control is absent or commented out or that it has been set to a null value. The two conditions have dramatically different and possibly opposed semantics.
• TWikiGuest is the guest account - used by unauthenticated users.
• The TWiki web must not deny view to TWikiGuest; otherwise, people will not be able to register.

Note: Above table comes from SitePermissions

• WikiName and encrypted password are recorded using the password manager if authentication is enabled.

• Set GROUP = Main.SomeUser, Main.OtherUser, Main.SomeGroup

• Set ALLOWTOPICCHANGE = Main.TWikiAdminGroup

The Super Admin Group

• Set GROUP= Main.ElizabethWindsor, Main.TonyBlair

Restricting Access

• Restricting VIEW blocks viewing and searching of content.
• Restricting CHANGE blocks creating new topics, changing topics or attaching files.
• Restricting RENAME controls who is allowed to rename, move or delete a topic.
  • To rename, move or delete a topic, the user also also needs VIEW and CHANGE permission. They also need CHANGE access to change references in any referring topics (though the rename can proceed without this access), and CHANGE access to the target topic.
• Restricting MANAGE controls access to certain management functions, such as 'create web'. It must be set in the TWiki web.

Controlling access to a Web

• 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.

• You can define these settings in the WebPreferences topic, preferable towards the end of the topic:
  • Set DENYWEBVIEW = < comma-delimited list of Users and Groups >
  • Set ALLOWWEBVIEW = < comma-delimited list of Users and Groups >
  • Set DENYWEBCHANGE = < comma-delimited list of Users and Groups >
  • Set ALLOWWEBCHANGE = < comma-delimited list of Users and Groups >
  • Set DENYWEBRENAME = < comma-delimited list of Users and Groups >
  • Set ALLOWWEBRENAME = < comma-delimited list of Users and Groups >

Be careful with empty values for any of these. In older versions of TWiki,

• Set ALLOWWEBVIEW =

• Set DENYWEBVIEW =

Controlling access to a Topic

• You can define these settings in the WebPreferences topic, preferable towards the end of the topic:
  • Set DENYTOPICVIEW = < comma-delimited list of Users and Groups >
  • Set ALLOWTOPICVIEW = < comma-delimited list of Users and Groups >
  • Set DENYTOPICCHANGE = < comma-delimited list of Users and Groups >
  • Set ALLOWTOPICCHANGE = < comma-delimited list of Users and Groups >
  • Set DENYTOPICRENAME = < comma-delimited list of Users and Groups >
  • Set ALLOWTOPICRENAME = < comma-delimited list of Users and Groups >

Remember when opening up access to specific topics within a restricted web that other topics in the web - for example, the WebLeftBar - may also be accessed when viewing the topics. The message you get when you are denied access should tell you what topic you were not permitted to access.

Be careful with empty values for any of these. In older versions of TWiki,

• Set ALLOWTOPICVIEW =

• Set DENYTOPICVIEW =

Controlling access to Attachments

  ScriptAlias /twiki/bin/ /filesystem/path/to/twiki/bin/
  Alias /twiki/pub/       /filesystem/path/to/twiki/pub/

How TWiki evaluates ALLOW/DENY settings

1. If the user is a super-user
   • access is PERMITTED.
2. If DENYTOPIC is set to a list of wikinames
   • people in the list will be DENIED.
3. If DENYTOPIC is set to empty ( i.e. Set DENYTOPIC = )
   • access is PERMITTED i.e no-one is denied access to this topic
4. If ALLOWTOPIC is set
   1. people in the list are PERMITTED
   2. everyone else is DENIED
      • Note that this means that setting ALLOWTOPIC to empty denies access to everyone except admins (unless DENYTOPIC is also set to empty, as described above)
5. If DENYWEB is set to a list of wikiname
   • people in the list are DENIED access
6. If ALLOWWEB is set to a list of wikinames
   • people in the list will be PERMITTED
   • everyone else will be DENIED
     • Note that setting ALLOWWEB to empty denies access to everyone except admins
7. If you got this far, access is PERMITTED

Access Control quick recipes

Obfuscating Webs

Authenticate all Webs and Restrict Selected Webs

Authenticate and Restrict Selected Webs Only

Hide Control Settings

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

TWiki:TWiki.TWikiAccessControlSupplement

-- Contributors: TWiki:Main.PeterThoeny, TWiki:Main.MikeMannix, TWiki:Main.CrawfordCurrie

Authentication vs. Access Control

Authentication: Identifies who a user is based on a login procedure. See TWikiUserAuthentication.

Access control: Restrict access to content based on users and groups once a user is identified.

• 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.

<style="background-color:#f5f5f5"> <!--
   * Set DENYTOPICCHANGE = Main.SomeGroup
-->

Restricting Read Access

Deny Viewing by Topic

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:

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

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

Authenticate and Restricting Selected Webs Only

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. 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.

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

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

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

• Create broad-based Groups (for more and varied input), and...
• Avoid creating view-only Users (if you can read it, you should be able to contribute to it).

• Users can be authenticated using Basic Authentication (htaccess) or SSL (secure server). In either case, TWikiUserAuthentication is required in order to track user identities, and use User and Group access control.

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

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 >

• 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:

• • 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 >

• 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:

• • 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 >

• • 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 - a search will turn up the "hidden" topic.

• 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.

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

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 >

• 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

• • 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 >

• 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

• • 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 NOSEARCHALL = on

• • Set NOSEARCHALL = on

• • 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.)

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)

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.

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

Restricting Web Access

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

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
#

# 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)

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. 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. TWiki will now remember the IP address of an authenticated user.

TWiki Access Control

Overview

An Important Control Consideration

Users and Groups

Managing Users