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-   -   Limit Login Dropbear CentOS (https://www.linuxquestions.org/questions/linux-newbie-8/limit-login-dropbear-centos-4175498192/)

dwaterboker 03-14-2014 12:11 PM

Limit Login Dropbear CentOS
 
Hello.

I am newbie and there is something to ask.

I want limit my client's login on Dropbear Centos.
Then I got this from my friend and he talked to me for trying it.
I asked him what is it, but he didn'n answer my question.

Here the codes.

Code:

PARAM=$1

echo -n > /tmp/pid2
ps ax|grep dropbear > /tmp/pid
cat /tmp/pid | grep -i 'dropbear -p' > /tmp/pids
cat /var/log/secure | grep -i "Password auth succeeded" > /tmp/sks
perl -pi -e 's/Password auth succeeded for//g' /tmp/sks
perl -pi -e 's/dropbear//g' /tmp/sks

cat /tmp/pid | while read line;do
set -- $line
p=$1
var=`cat /tmp/sks | grep -i $1`
set -- $var
l=$6
if [ "$6" != '' ]
then
echo "$p $l" | cat - /tmp/pid2 > /tmp/temp && mv /tmp/temp /tmp/pid2
fi
done

case $PARAM in

1)
echo -n > /tmp/user1
cat /tmp/pid2 | while read line;do
set -- $line
p=$1
u=$2
cat /tmp/user1 | grep -i $u > /dev/null
if [ $? = 1 ];then
echo $line >> /tmp/user1
else
kill $p
echo "kill $p user $u"
fi
done
rm -f /tmp/pid
rm -f /tmp/pid2
rm -f /tmp/pids
rm -f /tmp/sks
rm -f /tmp/user1
exit 0
;;
2)
echo -n > /tmp/user1
echo -n > /tmp/user2
cat /tmp/pid2 | while read line;do
set -- $line
p=$1
u=$2
cat /tmp/user1 | grep -i $u > /dev/null
if [ $? = 1 ];then
echo $line >> /tmp/user1
else
cat /tmp/user2 | grep -i $u > /dev/null
if [ $? = 1 ];then
echo $line >> /tmp/user2
else
kill $p
echo "kill $p user $u"
fi
fi
done
rm -f /tmp/pid
rm -f /tmp/pid2
rm -f /tmp/pids
rm -f /tmp/sks
rm -f /tmp/user1
rm -f /tmp/user2
exit 0
;;
*)
rm -f /tmp/pid
rm -f /tmp/pid2
rm -f /tmp/pids
rm -f /tmp/sks
exit 1

So, I entered those codes via Putty. But, there was nothing happen to my Linux.


The question now is:
- What are those codes?
- How I get command from those codes?


Sorry for my bad english.
Thank you.

shivaa 03-14-2014 12:52 PM

Is this complete code? It's a script without a shebang. But if you don't know what's it and what it can do, then why did you executed it? It could have a prank and could destroyed your system! And what do you mean by 'How I get command from those codes?', explain it little more.


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