New Order Form (Apache: The Definitive Guide)

5.5.1. DBM Files on Unix

Although searching a file of usernames and passwords works perfectly well, it is apt to be rather slow once the list gets up to a couple of hundred entries. To deal with this, Apache provides a better way of handling large lists: turning them into a database. You need one of the modules that appear in the Configuration file as:

#Module db_auth_module  mod_auth_db.o 
Module dbm_auth_module mod_auth_dbm.o

Bear in mind that they correspond to different directives: AuthDBMUserFile or AuthDBUserFile . A Perl script to manage both types of database, dbmmanage , is supplied with Apache in .../src/support. To decide which type to use, you need to discover the capabilities of your Unix. Explore these by going to the command prompt and typing first:

% man db

and then:

% man dbm

Whichever method first produces a manpage is the one you should use. You can also use an SQL database, employing MySQL or a third-party package to manage it.

Once you have decided which method to use, edit Configuration to include the appropriate module, and then type:

% ./Configure

and:

% make

We now have to create a database of our users: bill, ben, sonia, and daphne. Go to ... /apache/src/support, find the utility dbmmanage, and copy it into /usr/local/bin or something similar to put it on your path. This utility may be distributed without execute permission set, so, before attempting to run it, we may need to change the permissions:

% chmod +x dbmmanage

You may find, when you first try to run dbmmanage, that it complains rather puzzlingly that some unnamed file can't be found. This is probably Perl, a text-handling language, and if you have not installed it, you should. It may also be necessary to change the first line of dbmmanage to the correct path for Perl, if it is installed somewhere other than /usr/local/bin.

We use dbmmanage in the following way:

% dbmmanage dbmfile command username

The possible commands are as follows:

add
adduser
check
delete
import
update
view

So, to add our four users to a file /usr/www/ok_dbm/users, we type:

% dbmmanage /usr/www/ok_dbm/users.db adduser bill 
New password:theft
Re-type new password:theft
User bill added with password encrypted to vJACUCNeAXaQ2

Perform the same service for ben, sonia, and daphne. The file ... /users is not editable directly, but you can see the results by typing:

% dbmmanage /usr/www/ok_dbm/users view

bill:vJACUCNeAXaQ2
ben:TPsuNKAtLrLSE
sonia:M9x731z82cfDo
daphne:7DBV6Yx4.vMjc

You can build a group file with dbmmanage, but, because of faults in the script that we hope will have been rectified by the time readers of this edition use it, the results seem a bit odd. To add the user fred to the group cleaners, type:

% dbmmanage /usr/www/ok_dbm/group add fred cleaners

(Note: Do not use adduser.) dbmmanage rather puzzlingly responds with the following message:

User fred added with password encrypted to cleaners

When we test this with:

% dbmmanage  /usr/www/ok_dbm/group view

we see:

fred:cleaners

which is correct, because in a group file the name of the group goes where the encrypted password would go in a password file.

Since we have a similar file structure, we invoke DBM authentication in ... /conf/httpd.conf by commenting out:

#AuthUserFile /usr/www/ok_users/sales
#AuthGroupFile /usr/www/ok_users/groups

and inserting:

AuthDBMUserFile /usr/www/ok_dbm/sales 
AuthDBMGroupFile /usr/www/ok_dbm/sales

AuthDBMGroupFile is set to the same file as the AuthDBMUserFile. What happens is that the username becomes the key in the DBM file, and the value associated with the key is password:group. To create a separate group file, a database with usernames as the key and groups as the value (with no colons in the value) would be needed.

5.5. New Order Form

5.5.1. DBM Files on Unix