Password testing script: help pls

For any Unix server with FTP, I have written a short script that can
check if a user's password is the same as their login ID. But it's
impractical and difficult with sftp.

My current script:


#!/bin/ksh

FTP (){
ftp -in <<EF
open $(hostname)
user $USER $USER
quit
EF
}

USERS=$(cat /etc/shadow | cut -d\: -f1)
for USER in $USERS
do
echo "Testing ${USER}"
MESSAGES=""
MESSAGES=$(FTP $USER | grep failed )
if [[ -z $MESSAGES ]];then
echo " User \"$USER\": login and password the same. "
echo " User \"$USER\": login and password the same. " >>
test_pw.log
fi
done



Can anyone think of a means of scripting such a thing for a server
with FTP ripped out? It would go through every user in the shadow
file, and try to log in using the user ID as the password, and report
on anyone using such a weak password

Doing this with 6 or 10 users is easy manually of course, but many of
my servers have literally hundreds of users

Thnx in advance.