Apache module mod_auth_anon.c

### Apache HTTP Server Version 1.3

# Module mod_auth_anon

This module allows "anonymous" user access to authenticated areas.

Status: Extension
Source File: mod_auth_anon.c
Module Identifier: anon_auth_module
Compatibility: Available in Apache 1.1 and later.

## Summary

This module does access control in a manner similar to anonymous-ftp sites; i.e. have a 'magic' user id 'anonymous' and the email address as a password. These email addresses can be logged.

Combined with other (database) access control methods, this allows for effective user tracking and customization according to a user profile while still keeping the site open for 'unregistered' users. One advantage of using Auth-based user tracking is that, unlike magic-cookies and funny URL pre/postfixes, it is completely browser independent and it allows users to share URLs.

## Directives

- Anonymous
- Anonymous_Authoritative
- Anonymous_LogEmail
- Anonymous_MustGiveEmail
- Anonymous_NoUserID
- Anonymous_VerifyEmail

## Example

The example below (when combined with the Auth directives of a htpasswd-file based (or GDM, mSQL etc.) base access control system allows users in as 'guests' with the following properties:

- It insists that the user enters a userId. (`Anonymous_NoUserId`)
- It insists that the user enters a password. (`Anonymous_MustGiveEmail`)
- The password entered must be a valid email address, ie. contain at least one '@' and a '.'. (`Anonymous_VerifyEmail`)
- The userID must be one of `anonymous guest www test welcome` and comparison is not case sensitive.
- And the Email addresses entered in the passwd field are logged to the error log file (`Anonymous_LogEmail`)

Excerpt of httpd.conf:

>     Anonymous_NoUserId      off
>     Anonymous_MustGiveEmail on
>     Anonymous_VerifyEmail    on
>     Anonymous_LogEmail      on
>     Anonymous        anonymous guest www test welcome

>     AuthName                "Use 'anonymous' & Email address for guest entry"
>     AuthType                basic

>     # An AuthUserFile/AuthDBUserFile/AuthDBMUserFile
>     # directive must be specified, or use
>     # Anonymous_Authoritative for public access.
>     # In the .htaccess for the public directory, add:
>     <Files *>
>     Order Deny,Allow
>     Allow from all

>     Require valid-user
>     </Files>

## Anonymous directive

Syntax: Anonymous user [user] ...
Default: none
Context: directory, .htaccess
Override: AuthConfig
Status: Extension
Module: mod_auth_anon

A list of one or more 'magic' userIDs which are allowed access without password verification. The userIDs are space separated. It is possible to use the ' and " quotes to allow a space in a userID as well as the \ escape character.

Please note that the comparison is case-IN-sensitive.
I strongly suggest that the magic username '`anonymous`' is always one of the allowed userIDs.

Example:
`Anonymous anonymous "Not Registered" 'I don\'t know'`

This would allow the user to enter without password verification by using the userId's 'anonymous', 'AnonyMous','Not Registered' and 'I Don't Know'.

## Anonymous_Authoritative directive

Syntax: Anonymous_Authoritative on|off
Default: `Anonymous_Authoritative off`
Context: directory, .htaccess
Override: AuthConfig
Status: Extension
Module: mod_auth_anon

When set 'on', there is no fall-through to other authorization methods. So if a userID does not match the values specified in the `Anonymous` directive, access is denied.

Be sure you know what you are doing when you decide to switch it on. And remember that it is the linking order of the modules (in the Configuration / Make file) which details the order in which the Authorization modules are queried.

## Anonymous_LogEmail directive

Syntax: Anonymous_LogEmail on|off
Default: `Anonymous_LogEmail on`
Context: directory, .htaccess
Override: AuthConfig
Status: Extension
Module: mod_auth_anon

When set 'on', the default, the 'password' entered (which hopefully contains a sensible email address) is logged in the error log. The message is logged at a level of `info`, and so you must have LogLevel set to at least `info` in order to see this message.

Log entries will look like the following example:

    [Fri Apr 26 14:49:50 2002] [info] [client 192.168.1.105] Anonymous: Passwd  Accepted

## Anonymous_MustGiveEmail directive

Syntax: Anonymous_MustGiveEmail on|off
Default: `Anonymous_MustGiveEmail on`
Context: directory, .htaccess
Override: AuthConfig
Status: Extension
Module: mod_auth_anon

Specifies whether the user must specify an email address as the password. This prohibits blank passwords.

## Anonymous_NoUserID directive

Syntax: Anonymous_NoUserID on|off
Default: `Anonymous_NoUserID off`
Context: directory, .htaccess
Override: AuthConfig
Status: Extension
Module: mod_auth_anon

When set 'on', users can leave the userID (and perhaps the password field) empty. This can be very convenient for MS-Explorer users who can just hit return or click directly on the OK button; which seems a natural reaction.

## Anonymous_VerifyEmail directive

Syntax: Anonymous_VerifyEmail on|off
Default: `Anonymous_VerifyEmail off`
Context: directory, .htaccess
Override: AuthConfig
Status: Extension
Module: mod_auth_anon

When set 'on' the 'password' entered is checked for at least one '@' and a '.' to encourage users to enter valid email addresses (see the above `Auth_LogEmail`).

### Apache HTTP Server Version 1.3