1 ssh record
Environment: server, system CentOS 7.2
1.1 View normal login
Use command
last1.2 View ssh login failure records
grep "Failed password for root" /var/log/secure | awk '{print $11}' | sort | uniq -c | sort -nr | more2 Use denyhosts to prevent brute force cracking
DenyHosts is a program written in Python language. It will analyze the sshd log file /var/log/secure and record the IP to the /etc/hosts.deny file when repeated attacks are found to achieve the function of automatically screen IP.
2.1 Installation script
The installation server is required to have Internet access and create a /work directory
#!/bin/bash
wget http://sourceforge.net/projects/denyhosts/files/denyhosts/2.6/DenyHosts-2.6.tar.gz #下载软件
tar -zxvf DenyHosts-2.6.tar.gz #解压
mv DenyHosts-2.6 denyhost #为了方便改个名
cd denyhost/ #进入目录
yum install python -y #安装python
python setup.py install #安装denyhost,脚本
cd /usr/share/denyhosts/ #进入配置目录
cp daemon-control-dist daemon-control #为了方便改变配置文件名称
cp denyhosts.cfg-dist denyhosts.cfg #修改服务文件名称
chown root daemon-control #修改服务文件名称
chmod 700 daemon-control #提高安全级别修改权限
ln -s /usr/share/denyhosts/daemon-control /etc/init.d/denyhosts #创建启动服务连接软连接
chkconfig denyhosts on #添加启动项
cp denyhosts.cfg denyhosts.cfg.bak #备份配置文件为修改配置做准备
#cat /workspace/denyhost.txt > /usr/share/denyhosts/denyhosts.cfg
#将配置文件内容导入配置文件我的配置文件安装之前已经配置好了
/etc/init.d/denyhosts start #启动服务
echo install succeed!
2.2 Configuration file content
#cat /workspace/denyhost.txt > /usr/share/denyhosts/denyhosts.cfg
###########################2##################################
[root@107 workspace]# more denyhost.txt
SECURE_LOG = /var/log/secure
#ssh日志文件
HOSTS_DENY = /etc/hosts.deny
#将阻止IP写入到hosts.deny
PURGE_DENY = 5m
#过多久后清除已经禁止的其中w代表周d代表天h代表小时s代表秒m代表分钟
BLOCK_SERVICE = sshd
#阻止服务名
DENY_THRESHOLD_INVALID = 5
#允许无效用户在/etc/passwd未列出登录失败次数,允许无效用户登录失败的次数.
DENY_THRESHOLD_VALID = 5
#允许普通用户登录失败的次数
DENY_THRESHOLD_ROOT = 5
#允许root登录失败的次数
DENY_THRESHOLD_RESTRICTED = 1
#设定 deny host 写入到该资料夹
WORK_DIR = /usr/share/denyhosts/data
#将deny的host或ip纪录到Work_dir中
SUSPICIOUS_LOGIN_REPORT_ALLOWED_HOSTS = YES
HOSTNAME_LOOKUP=YES
#是否做域名反解
LOCK_FILE = /var/lock/subsys/denyhosts
#将DenyHOts启动的pid纪录到LOCK_FILE中已确保服务正确启动防止同时启动多个服务。
ADMIN_EMAIL = [email protected]
#设置管理员邮件地址
SMTP_HOST = localhost
SMTP_PORT = 25
SMTP_FROM = DenyHosts
SMTP_SUBJECT = DenyHosts Report
AGE_RESET_VALID=1d
#有效用户登录失败计数归零的时间
AGE_RESET_ROOT=1d
#root用户登录失败计数归零的时间
AGE_RESET_RESTRICTED=5d
#用户的失败登录计数重置为0的时间(/usr/share/denyhosts/data/restricted-usernames)
AGE_RESET_INVALID=10d
#无效用户登录失败计数归零的时间
DAEMON_LOG = /var/log/denyhosts
#自己的日志文件
DAEMON_SLEEP = 30s
DAEMON_PURGE = 5m
#该项与PURGE_DENY 设置成一样也是清除hosts.deniedssh 用户的时间
2.3 Other
If you want to delete a banned host IP and add it to the list of allowed hosts, it is useless to delete it only in /etc/hosts.deny. Need to enter the /var/lib/denyhosts directory to enter the following operations
1. Stop DenyHosts service $ sudo service denyhosts stop
2. Delete the host IP you want to cancel in /etc/hosts.deny
3. Edit all files in the DenyHosts working directory to pass
$ sudo grep 192.168.1.191 /usr/share/denyhosts/data/*
Then delete the lines of the host IP that you want to cancel in the file one by one
* /usr/share/denyhosts/data/hosts
* /usr/share/denyhosts/data/hosts-restricted
* /usr/share/denyhosts/data/hosts-root
* /usr/share/denyhosts/data/hosts-valid
* /usr/share/denyhosts/data/users-hosts
4. Add the IP address of the host you want to allow to
/var/lib/denyhosts/allowed-hosts
vi /usr/share/denyhosts/data/allowed-hostsps
# We mustn’t block localhost
127.0.0.1
192.168.1.*
5. Start DenyHosts service service denyhosts start
View denyhosts service status:
/etc/init.d/denyhosts statusor
service denyhosts status
Reference materials: