Protect unix/linux directory using .htaccess and .htpasswd

This is a note on protecting unix/linux directory using .htaccess and .htpasswd.
The article below is copied from [1].

References:
[1] HTPassword Tutorial
[2] Password Protection with .htaccess & .htpasswd
[3] Apache HTTP Server Tutorial: .htaccess files

Password Tutorial

If you would like to have a set of web pages that are protected, requiring a username/password to gain access, this tutorial will show you how to set it up. This is geared towards the Unix Apache httpd servers used on holly, lamar, and www.colostate.edu. If you are using another web server, you'll need to check that server's documentation to see how to do this.

Steps to Password-protect a Directory

First, create a subdirectory in your web area. For the sake of this tutorial, I have created the "protect" directory. Set the permissions on the directory so that the server has read/execute. I do this by using the local command chgrp-www to set the group to the www group. This is the group that the server runs under at Colorado State University for the lamar, holly and www servers. I have used the -sd flag which sets "set group id" for a directory. This will then force any files you create within the protect directory to the www group, so if you ftp files to this directory they will be automatically readable by the server but not by any other user on the system. I then cd into the protect directory.

cd ~ric/public_html
mkdir protect
chmod g+r,g+x,o-r,o-x protect
chgrp-www -sd protect
cd protect

Next you must create a .htaccess file inside the directory you want protected. You can use either the vi or pico editors on the supported systems mentioned above or ftp the file to this directory. If you are new to unix or know little about vi then I suggest you use the pico editor or ftp the .htaccess file. The command to edit with pico is "pico .htaccess". The .htaccess file should contain the following lines. The items in bold are things you will want to change depending on the location of the AuthUserFile and content of AuthName.

AuthUserFile /z/ric/secret/.htpasswd
AuthGroupFile /dev/null
AuthName "Ric's protected files"
AuthType Basic

<Limit GET>
require valid-user
</Limit>

The AuthName is what the user will see when they're prompted for a password - something to the effect of "Enter the username for Ric's Protected files". The AuthUserFile is location of the password file and should be not accessible with a url on the server for security reasons. This is a full unix path and the permissions should be set up like the "protect" directory using the chmod and chgrp-www commands above so the only one that can read this file is the owner and the server. To get the full path of a directory, cd to that directory and enter the command "pwd" to print the working directory path. Now you'll have to set up the password file. You'll need to use the htpasswd program. It is included with the Apache httpd server.
First cd to the directory that contains the password file. In this example the password file is called .htpasswd and is in the directory /z/ric/secret/ as indicated by the AuthUserFile file entry in the .htaccess file. For every username you want to add to the password file, enter the following. (the -c is only required the first time; it indicates that you want to create the .htpasswd file).

   cd
   mkdir secret
   cd secret
   htpasswd -c .htpasswd pumpkin
     [ you're prompted for the password for pumpkin]
     [ if you have other users enter the following. Don't use the -c]
   htpasswd .htpasswd user2
   htpasswd .htpasswd user3

Again, make sure the permissions are set up like the "protect" directory using the chmod and chgrp-www commands above so the only one that can read files in the "secret" directory is the owner and the server. Here is the protected page using the above setup to password protect this page. The username is "pumpkin" and password is "pie".