Apache Module mod_authn_anon
Summary
This module provides authentication front-ends such as
mod_auth_basic to authenticate users 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.
When using mod_auth_basic, this module is invoked
via the AuthBasicProvider
directive with the anon value.

The example below is combined with "normal" htpasswd-file based
authentication and allows users in additionally 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, i.e.
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. (Anonymous)
- And the Email addresses entered in the passwd field are
logged to the error log file.
(
Anonymous_LogEmail)
Example
<Directory /foo>
AuthName "Use 'anonymous' & Email address for guest entry"
AuthType Basic
AuthBasicProvider file anon
AuthUserFile /path/to/your/.htpasswd
Anonymous_NoUserID off
Anonymous_MustGiveEmail on
Anonymous_VerifyEmail on
Anonymous_LogEmail on
Anonymous anonymous guest www test welcome
Order Deny,Allow
Allow from all
Require valid-user
</Directory>

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.
It's strongly recommended 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 userIDs "anonymous",
"AnonyMous", "Not Registered" and "I Don't Know".
As of Apache 2.1 it is possible to specify the userID as
"*". That allows any supplied userID to be
accepted.

When set On, the default, the 'password' entered
(which hopefully contains a sensible email address) is logged in
the error log.
Specifies whether the user must specify an email address as
the password. This prohibits blank passwords.
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.
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 Anonymous_LogEmail).