ssh訪問控制，多次失敗登錄即封掉IP，防止暴力破解

1.

大於10次登陸失敗就封掉IP，編寫shell腳本：secure_ssh.sh

#! /bin/bash
cat /var/log/secure|awk '/Failed/{print $(NF-3)}'|sort|uniq -c|awk '{print $2"="$1;}' > /usr/local/bin/black.txt
for i in `cat  /usr/local/bin/black.txt`
do
        IP=`echo $i |awk -F= '{print $1}'`
        NUM=`echo $i|awk -F= '{print $2}'`
        result=$(cat /etc/hosts.deny | grep $IP)
        if [[ $NUM -gt 10 ]];then
                if [[ $result = "" ]];then
                        echo "sshd: $IP" >> /etc/hosts.deny
                fi
        fi
done

2.

定時任務：10分鐘執行一次，crontab -e

*/10 * * * * bash /usr/local/bin/secure_ssh.sh