You can generate the username and password using htpasswd. New file:
$ htpasswd -c /srv/auth/.htpasswd squire
To append to existing file:
$ htpasswd -b /srv/auth/.htpasswd squire2 tickleme2
Checar en la directiva httpd.conf
AuthUserFile ‘/some/other/dir/.htpasswd’
Fuente: http://serverfault.com/questions/127708/how-to-configure-basic-authentication-in-apache-httpd-virtual-hosts