validate username with ip

[Darren Etheridge_2]

What is the best way to validte a users usernaem with the IP they are telneting into a system with? We have users that use others accounts to log into our systems.

[Geoff Wild]

Reset all user passwords - and tell them not to give them out to anybody!!!

You can NOT validate the person who is using userid: jsmith as the real jsmith - unless you are using sophisticated logins with say finger printing or retinal scans.

Rgds...Geoff

[RAC_1]

who -u will give you ip addresses from where users have logged in. (You may also want to use getip command to check there ip address)
(Or you may have list with you already)

Also you can prepare a user list from /etc/passwd or with logins -u command.

Now you have ip address and user name. Not put a code in /etc/profile to check username and check if it is coming from a particular ip. If allow access, else do what you want-log them out, send message, whatever

Something like follows.

usr_id=@(whoami)
ip_address=$(getip "$(who -um|awk '{print $NF}'|awk -F : '{print $1}')")
fix_ip=$(grep -q ${user_id} /var/adm/file|awk '{print $2}')
#/var/adm/file will have details about userid and their ip addresses. Like follows.
# xxx 10.9.12.20
#Second awk is required to take care of CDE, Exceed, Reflection logins)

if [[ ${user_id} -eq ${user_id} && ${ip_address != ${fix_ip} ]]
then
echo "Access not allowed"
exit
fi

### Script not tested.

[Bill Hassell]

Unless every PC or laptop has a fixed IP address (fairly uncommon), the IP address will change from time to time. However, it's fairly easy to control this errant behavior. Anytime a user is caught using the wrong login, you disable the account. Then when either user asks for help, you march both of them together into the IT Director's office and they are given a single warning never to do this again, or they will *BOTH* be fired.

Trying to workaround behavioral problems like this means that users will still try to get around the system no matter what. It's a symptom of non-support for your security policies. Your systems are safe when everyone takes all the policies seriously.

[Robert Salter · Accepted solution]

I agree with Geoff. What are your security procedures? If I log in as someone else and screw something up who's responsible, me or the person I logged in as? Or you.