CentOS, DenyHosts, SSH
公司伺服器每天都會有上千的SSH失敗嘗試記錄,一直不停的掃描,這些人真夠無 聊的,沒事吃飽了撐著,盡找些軟體在那裡窮舉掃描（幸好伺服器密碼設置的夠長夠複雜）.
要一條一條將這些IP阻止顯然治標不治本,於是找了個DenyHosts軟體來代替的偶的手工活,吼吼:)
DenyHosts是Python語言寫的一個程序,它會分析SSHD的日誌文件,當發現重複的攻擊時就會記錄IP到/etc/hosts.deny文件,從而達到自動屏蔽IP的功能.
DenyHosts官方網站為：http://denyhosts.sourceforge.net
以下是安裝記錄（以CentOS 4.4, DenyHosts 2.6 為例）
# cd /usr/local/src# wget http://jaist.dl.sourceforge.net/sourceforge/denyhosts/DenyHosts-2.6.tar.gz
# tar -zxvf DenyHosts-2.6.tar.gz
# cd DenyHosts-2.6
# python setup.py install
默認是安裝到/usr/share/denyhosts/目錄的.
# cd /usr/share/denyhosts/# cp denyhosts.cfg-dist denyhosts.cfg
# vi denyhosts.cfg
這裡根據自己需要進行相應的配置
# cp daemon-control-dist daemon-control# vi daemon-control
DENYHOSTS_BIN = "/usr/bin/denyhosts.py"
DENYHOSTS_LOCK = "/var/lock/subsys/denyhosts"
DENYHOSTS_CFG = "/usr/share/denyhosts/denyhosts.cfg"
# chown root daemon-control
# chmod 700 daemon-control
完了之後執行daemon-contron start就可以了.
# ./daemon-control start
如果要使DenyHosts每次重起后自動啟動還需做如下設置：
# cd /etc/init.d
# ln -s /usr/share/denyhosts/daemon-control denyhosts
# chkconfig --add denyhosts
# chkconfig --level 2345 denyhosts on
或者修改/etc/rc.local文件：
# vi /etc/rc.local
加入下面這條命令
/usr/share/denyhosts/daemon-control start
DenyHosts配置文件說明：
SECURE_LOG = /var/log/secure
#sshd日誌文件,它是根據這個文件來判斷的,不同的操作系統,文件名稍有不同.
HOSTS_DENY = /etc/hosts.deny
#控制用戶登陸的文件
PURGE_DENY = 5m
#過多久后清除已經禁止的
BLOCK_SERVICE = sshd
#禁止的服務名
DENY_THRESHOLD_INVALID = 1
#允許無效用戶失敗的次數
DENY_THRESHOLD_VALID = 10
#允許普通用戶登陸失敗的次數
DENY_THRESHOLD_ROOT = 5
#允許root登陸失敗的次數
HOSTNAME_LOOKUP=NO
#是否做域名反解
DAEMON_LOG = /var/log/denyhosts
#DenyHosts的日誌文件
效果:
May 13 13:17:37 web sshd[3863]: Failed password for huzi from ::ffff:192.168.0.145 port 2743 ssh2
May 13 21:17:44 web sshd[3862]: Failed password for huzi from ::ffff:192.168.0.145 port 2743 ssh2
May 13 13:17:44 web sshd[3863]: Failed password for huzi from ::ffff:192.168.0.145 port 2743 ssh2
May 13 21:17:48 web sshd[3862]: Failed password for huzi from ::ffff:192.168.0.145 port 2743 ssh2
May 13 13:17:48 web sshd[3863]: Failed password for huzi from ::ffff:192.168.0.145 port 2743 ssh2
May 13 21:18:04 web sshd[3862]: Failed password for huzi from ::ffff:192.168.0.145 port 2743 ssh2
May 13 13:18:04 web sshd[3863]: Failed password for huzi from ::ffff:192.168.0.145 port 2743 ssh2
May 13 13:18:04 web sshd[3863]: Disconnecting: Too many authentication failures for huzi
