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# <a name="TWiki_User_Authentication"> TWiki User Authentication </a>

_TWiki site access control and user activity tracking_

## <a name="Overview"> Overview </a>

TWiki does not authenticate users internally, it depends on the `REMOTE_USER` environment variable. This variable is set when you enable Basic Authentication (.htaccess) or SSL "secure server" authentication (https protocol).

TWiki uses visitor identification to keep track of who made changes to topics at what time and to manage a wide range of personal site settings. This gives a complete audit trail of changes and activity.

## <a name="Authentication_Options"> Authentication Options </a>

No special installation steps are required if the server is already authenticated. If it isn't, you have three standard options for controlling user access:

1. **Forget about authentication** to make your site completely public - anyone can browse and edit freely, in classic Wiki mode. All visitors are assigned the %MAINWEB%.TWikiGuest default identity, so you can't track individual user activity. <br />
2. **Use SSL** (Secure Sockets Layer; HTTPS) to authenticate and secure the whole server. <br />
3. **Use Basic Authentication (.htaccess)** to control access by protecting key scripts: `attach`, `edit=`, `installpasswd`, `preview`, `rename`, `save`, `upload` using the .htaccess file. The [[TWikiInstallationGuide]] has step-by-step instructions.

### <a name="Partial_Authentication"> Partial Authentication </a>

**Tracking by IP address** is an experimental feature, enabled in `lib/TWiki.cfg`. It lets you combine open access to some functions, with authentication on others, with full user activity tracking:

* Normally, the <code>**REMOTE\_USER**</code> environment variable is set for the scripts that are under authentication. If, for example, the <code>**edit**</code>, <code>**save**</code> and <code>**preview**</code> scripts are authenticated, but not <code>**view**</code>, you would get your [[WikiName]] in <code>**preview**</code> for the <code>**%WIKIUSERNAME%**</code> variable, but <code>**view**</code> will show <code>**TWikiGuest**</code> instead of your WikiName.

* TWiki can be configured to remember the IP address/username pair whenever an authentication happens (edit topic, attach file). Once remembered, the non-authenticated scripts, like <code>**view**</code>, will show the correct username instead of %MAINWEB%.TWikiGuest.

* Enable this feature by setting the <code>**$doRememberRemoteUser**</code> flag in `TWiki.cfg`. TWiki then persistently stores the IP address/username pairs in the file, `$remoteUserFilename`, which is `"$dataDir/remoteusers.txt"` by default.

* **_NOTE:_** This approach can fail if the IP address changes due to dynamically assigned IP addresses or proxy servers.

**Quick Authentication Test** - Use the %WIKIUSERNAME% variable to return your current identity:

* You are %WIKIUSERNAME%

## <a name="TWiki_Username_vs_Login_Username"> TWiki Username vs. Login Username </a>

This section applies only if your %WIKITOOLNAME% is installed on a server that is both **authenticated** and on an **intranet**.

%WIKITOOLNAME% internally manages two usernames: Login username and TWiki username.

* **Login username:** When you login to the intranet, you use your existing login username, ex: <code>**pthoeny**</code>. This name is normally passed to %WIKITOOLNAME% by the <code>**REMOTE\_USER**</code> environment variable, and used by internally by %WIKITOOLNAME%. Login usernames are maintained by your system administrator.

* **TWiki username:** Your name in [[WikiNotation]], ex: <code>**PeterThoeny**</code>, is recorded when you register using [[TWikiRegistration]]; doing so also generates a personal home page in the %MAINWEB% web.

%WIKITOOLNAME% can automatically map an intranet username to a TWiki username, provided that the username pair exists in the %MAINWEB%.%WIKIUSERSTOPIC% topic. This is also handled automatically when you register.

> **_NOTE:_**
>
> **To correctly enter a [[WikiName]]**
>
> - your own or someone else's - be sure to include the %MAINWEB% web name in front of the Wiki username, followed by a period, and no spaces. Ex:
>
> <div>
>   <center><code><b>%MAINWEB%.<nop>WikiUsername</nop></b></code> or <code><b>%<nop>MAINWEB%.<nop>WikiUsername</nop></nop></b></code></center>
> </div>
>
> This points
>
> <code>**WikiUser**</code>
>
> to the %WIKITOOLNAME%.%MAINWEB% web, where user registration pages are stored, no matter which web it's entered in. Without the web prefix, the name appears as a
>
> 
>
> [[NewTopic]]
>
> everywhere but in the %MAINWEB% web.

<a name="ChangingPasswords"></a>

## <a name="Changing_Passwords"> Changing Passwords </a>

Change and reset passwords using forms on regular pages. Use [[TWikiAccessControl]] to restrict use as required.

* The [[ChangePassword]] form ( <code>**TWiki/ChangePassword**</code> ):

> %INCLUDE\{"ChangePassword"\}%

* The [[ResetPassword]] form ( <code>**TWiki/ResetPassword**</code> ):

> %INCLUDE\{"ResetPassword"\}%

-- [[MikeMannix]] - 29 Aug 2001