If you want to mirror a phpbb or other CMS that ask for an authentication, you can get the coockis from the firefox dir.
In my case is:
cp /home/gnuton/.mozilla/firefox/xxxxxx.default/cookies.sqlite .
Then convert the coockies file from sqlite to plain paper with this script
gnuton@iron:/tmp/SS$ cat SS
#!/bin/bash
#
sqlite3 $1 <<EOF
.mode tabs
.header off
select host as domain,
case substr(host,1,1)=’.’ when 0 then ‘FALSE’ else ‘TRUE’ end as flag,
path,
case isSecure when 0 then ‘FALSE’ else ‘TRUE’ end as secure,
expiry as expiration, name, value from moz_cookies;
EOF
The you have your plaintext cookies file and you can run now wget to do the job.
$ wget –load-cookies cookies.txt -m -np http://mywebsite.com
