Linux 安全设置脚本，部分配置按需修改
#!/bin/bash
# Filename: security_setting.sh
# Author: Jeff.Cui
# Date: 2023-05-22
############### 安全设置主要修改功能 ###############
# 修改禁止 root ssh 登录，如只有root用户，则添加用户：dbaadmin/DBA_Test1 用户；
# 修改 ssh 端口为 922 ；
# 修改密码最大可用时间180天，最少8位大写字母、小写字母、数字、特殊字符；
# 修改限制IP网段访问，hosts.allow 和 firewalld
# 修改超时限制 1800s；
# 红字、高亮
RGB_DANGER() {
echo -e "n33[31;1m# $1 33[0mn"
}
# 白字、半亮
RGB_WAIT() {
echo -e "n33[37;2m# $1 33[0mn"
}
# 绿字、高亮
RGB_SUCCESS() {
echo -e "n33[32;1m# $1 33[0mn"
}
# 黄字、半亮
RGB_WARNING() {
echo -e "n33[33;2m# $1 33[0mn"
}
# 天蓝字、半亮
RGB_INFO() {
echo -e "n33[36;2m# $1 33[0m"
}
# 检查操作系统大版本，如6/7/8
CHECK_VER=$(egrep "^VERSION_ID" /etc/os-release | cut -d" -f2 | cut -d. -f1)
# 检查 RAM 大小，此处未使用
CHECK_RAM=$(cat /proc/meminfo | grep "MemTotal" | awk -F" " '{ram=$2/1024/1024}{printf("%.0f",ram)}')
# 设置日志名字，脚本同目录下
conflog=linux_security_$(date +'%Y%m%d').log
# 检查 kernel 版本，用以同 4.9 比较大小，BBR 要求 4.9 及以上版本
KERN=$(uname -r | awk -F. '{ printf("%d.%dn",$1,$2); }')
kern_int=$(echo $KERN|cut -d. -f1)
kern_dec=$(echo $KERN|cut -d. -f2)
if [ $kern_int -gt 4 ];then
cansue_bbr = "Y"
elif [ $kern_int -eq 4 ] && [ $kern_dec -ge 9 ];then
cansue_bbr = "Y"
fi
# 检查是否 root 执行
check_root() {
if [[ $EUID -ne 0 ]]; then
RGB_DANGER "This script must be run as root!"
exit 1
fi
}
# 检查 OS 版本是否为 7
check_os() {
if [ "${CHECK_VER}" != '7' ]; then
RGB_DANGER "This script must be run on Linux 7!"
exit 1
fi
}
# 启用 BBR，防止网络拥塞,需要内核版本>=4.9
open_bbr() {
echo "============= bbr =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
sed -i '/default_qdisc|BBR|tcp_congestion_control/d' /etc/sysctl.conf
echo "# BBR" >>/etc/sysctl.conf
echo "net.core.default_qdisc=fq" >>/etc/sysctl.conf
echo "net.ipv4.tcp_congestion_control=bbr" >>/etc/sysctl.conf
sysctl -p >>${conflog} 2>&1
sysctl -n net.ipv4.tcp_congestion_control >>${conflog} 2>&1
lsmod | grep bbr >>${conflog} 2>&1
RGB_SUCCESS "Configuration Success"
}
# 设置禁用 SELinux
disable_selinux() {
echo "============= selinux =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
seconf=$(grep -i ^selinux= /etc/selinux/config | sed 's/ //g' | cut -d= -f2)
seconf=$(echo $seconf | tr [:upper:] [:lower:])
if [ "${seconf}" != "disabled" ];then
sed -i 's/^SELINUX=.*$/SELINUX=disabled/g' /etc/selinux/config
setenforce 0
else
RGB_INFO "SELinux already configed to 'disabled',see /etc/selinux/config:$(grep -i ^selinux= /etc/selinux/config)"
fi
# systemctl disable firewalld.service >>${conflog} 2>&1
# systemctl stop firewalld.service >>${conflog} 2>&1
RGB_SUCCESS "Configuration Success"
}
# 设置仅允许指定 IP 可以 ssh 登录
limit_sshIP() {
sed -i '/10.10.212.89/d' /etc/hosts.allow
echo "sshd:10.10.212.89/255.255.252.0" >>/etc/hosts.allow
sed -i '/sshd:/d' /etc/hosts.deny
echo 'sshd:ALL' /etc/hosts.deny
systemctl restart firewalld # 开启防火墙
systemctl enable firewalld # 开机自启动防火墙
firewall-cmd --zone=public --list-rich-rules
firewall-cmd --permanent --remove-service=ssh
firewall-cmd --permanent --zone=public --remove-service=ssh # 取消没有限制的ssh服务，限制远程登录
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="192.168.56.0/23" port protocol="tcp" port="922" accept' #添加 192.168.56.0/23 网段 访问 922号端口白名单
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="10.10.212.89/22" port protocol="tcp" port="922" accept' #添加 10.10.212.89/22 网段 访问 922号端口白名单
firewall-cmd --reload # 生效设置
firewall-cmd --zone=public --list-rich-rules
}
# 设置时区为东八区 'Asia/Shanghai' "+0800"
time_zone() {
echo "============= time zone =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
if [ "$(date +%z)" != "+0800" ];then
rm -rf /etc/localtime >>${conflog} 2>&1
ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime >>${conflog} 2>&1
ls -ln /etc/localtime >>${conflog} 2>&1
else
tz=$(echo " $(ls -l /etc/localtime | awk -F"/" '{print $(NF-1)"/"$NF}') ($(date +'%Z, %z'))" | sed 's/^ //g')
RGB_INFO "Time Zone already set to 'Asia/Shanghai', like $tz,see /etc/localtime"
fi
RGB_SUCCESS "Configuration Success"
}
# 可选，测试环境可用
custom_profile() {
echo "============= custom profile =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
cat >/etc/profile.d/secu.sh >${conflog} 2>&1
RGB_SUCCESS "Configuration Success"
}
# 禁用 ctrl-alt-del 重启组合键
disable_cad() {
echo "============= disable cad =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
if [ -h /etc/systemd/system/ctrl-alt-del.target ];then
rm -rf /usr/lib/systemd/system/ctrl-alt-del.target
RGB_INFO "removed ctrl-alt-del.target link"
else
RGB_INFO "Already removed ctrl-alt-del.target link"
fi
# systemctl mask ctrl-alt-del.target >>${conflog} 2>&1 # 创建或修改软连接指向 /dev/null
RGB_SUCCESS "Configuration Success"
}
# 锁定没有登录权限的账户
lock_user() {
echo "============= Lock users =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
for account in $(egrep "/sbin/nologin" /etc/passwd | cut -f 1 -d ":"); do
passwd -l $account 2>&1 >/dev/null
done
# 如果只有 root 账户可登录系统，则建立其他管理员账户，如：dbaadmin/DBA_Test1
if [ $(egrep "/bin/bash|/bin/csh|/bin/sh" /etc/passwd | cut -f 1 -d ":" | grep -v root| wc -l) -eq 0 ];then
useradd dbaadmin -g wheel -G wheel
echo "DBA_Test1" | passwd --stdin dbaadmin
fi
# cut -d : -f 1 /etc/passwd >>${conflog} 2>&1
# for g in adm lp mail games ftp; do
# groupdel ${g} >>${conflog} 2>&1
# done
# cat /etc/group >>${conflog} 2>&1
RGB_SUCCESS "Configuration Success"
}
# 系统文件权限
sys_permissions() {
echo "============= sys permissions =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
chmod 644 /etc/passwd >>${conflog} 2>&1
chmod 644 /etc/group >>${conflog} 2>&1
chmod 000 /etc/shadow >>${conflog} 2>&1
chmod 000 /etc/gshadow >>${conflog} 2>&1
ls -la /etc/passwd >>${conflog} 2>&1
ls -la /etc/group >>${conflog} 2>&1
ls -la /etc/shadow >>${conflog} 2>&1
ls -la /etc/gshadow >>${conflog} 2>&1
RGB_SUCCESS "Configuration Success"
}
#修改已经存在的账户的密码过期时间
exist_account_pwd_policy() {
name=$(egrep "/bin/bash|/bin/csh|/bin/sh" /etc/passwd | grep -v root | awk -F ":" '{print $1}')
echo "Check exist account and change expire time for password..."
if [ -n "$name" ]; then
for i in $name; do
passwd -n 2 -x 180 -w 7 $i 2>&1 >/dev/null
done
printf "OKn"
else
printf "Do not exist account,OKn"
fi
}
# 修改默认密码策略，对后加账户生效
password_policy() {
echo "============= default password policy =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
passwd_maxdays=$(grep -i ^PASS_MAX_DAYS /etc/login.defs | awk '{print $2}')
if [ $passwd_maxdays -gt 180 ];then
cp /etc/login.defs /etc/login.defs.$(date +'%F')
sed -i 's/^PASS_MAX_DAYS.*$/PASS_MAX_DAYS 180/' /etc/login.defs
sed -i 's/^PASS_MIN_DAYS.*$/PASS_MIN_DAYS 0/' /etc/login.defs
sed -i 's/^PASS_MIN_LEN.*$/PASS_MIN_LEN 8/' /etc/login.defs
sed -i 's/^PASS_WARN_AGE.*$/PASS_WARN_AGE 7/' /etc/login.defs
else
RGB_INFO "Default Password lifetime policy already changed, do nothing"
fi
grep -Ev "^$|^#" /etc/login.defs >>${conflog} 2>&1
# 修改密码复杂度
plnum=$(grep -Ei "^minlen|^difok|^dcredit|^ucredit|^ocredit|^lcredit" /etc/security/pwquality.conf| wc -l)
if [ $plnum -eq 0 ];then
cat >>/etc/security/pwquality.conf >${conflog} 2>&1
RGB_WAIT "Configuring..."
sed -i 's/^INACTIVE.*$/INACTIVE=180/' /etc/default/useradd
cat /etc/default/useradd >>${conflog} 2>&1
RGB_SUCCESS "Configuration Success"
}
# 配置 ssh 策略
sec_ssh() {
echo "============= ssh 安全设置（禁止root登录、修改ssh默认端口为922） =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
cp /etc/ssh/sshd_config /etc/ssh/sshd_config_$(date +'%F')
sed -i '/^UseDNS|^Port|^AllowTcpForwarding|^X11UseLocalhost|^X11Forwarding|^LoginGraceTime|^PermitEmptyPasswords|^PubkeyAuthentication|^MaxAuthTries|^ClientAlive|^PermitRootLogin/d' /etc/ssh/sshd_config
sed -i '/^#UseDNS/aUseDNS no' /etc/ssh/sshd_config
sed -i '/^#Port/aPort 922' /etc/ssh/sshd_config
sed -i '/^#AllowTcpForwarding/aAllowTcpForwarding yes' /etc/ssh/sshd_config
sed -i '/^#X11UseLocalhost/aX11UseLocalhost no' /etc/ssh/sshd_config
sed -i '/X11Forwarding/aX11Forwarding yes' /etc/ssh/sshd_config
sed -i '/^#LoginGraceTime/aLoginGraceTime 90' /etc/ssh/sshd_config
sed -i '/^#PermitEmptyPasswords/aPermitEmptyPasswords no' /etc/ssh/sshd_config
sed -i '/^#PubkeyAuthentication/aPubkeyAuthentication yes' /etc/ssh/sshd_config
sed -i '/^#MaxAuthTries/aMaxAuthTries 5' /etc/ssh/sshd_config
sed -i '/^#ClientAliveInterval/aClientAliveInterval 60' /etc/ssh/sshd_config
sed -i '/^#ClientAliveCountMax/aClientAliveCountMax 3' /etc/ssh/sshd_config
sed -i '/^#PermitRootLogin/aPermitRootLogin no' /etc/ssh/sshd_config
sed -i "s/#Banner none/Banner /etc/issue.net/g" /etc/ssh/sshd_config
echo "ATTENTION:You have logged onto a secured server, ONLY Authorized users can access..." > /etc/issue
echo "ATTENTION:You have logged onto a secured server, ONLY Authorized users can access..." > /etc/issue.net
echo "ATTENTION:You have logged onto a secured server, ONLY Authorized users can access..." > /etc/motd
systemctl restart sshd >/dev/null 2>&1
grep -Ev "^$|^#" /etc/ssh/sshd_config >>${conflog} 2>&1
RGB_SUCCESS "Configuration Success"
}
# 禁用 USB 设备
dsiable_usb() {
echo "============= 禁用 USB 设备 =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
echo "install usb-storage /bin/true" >/etc/modprobe.d/block_usb.conf
cat /etc/modprobe.d/block_usb.conf >>${conflog} 2>&1
RGB_SUCCESS "Configuration Success"
}
# 超时设置
timeout_config() {
echo "============= timeout config =============" >>${conflog} 2>&1
RGB_WAIT "Configuring..."
echo "export TMOUT=1800" >>/etc/profile.d/custom.conf
cat /etc/profile.d/custom.conf >>${conflog} 2>&1
RGB_SUCCESS "Configuration Success"
}
# 询问是否重启 OS, reboot
reboot_os() {
RGB_WARNING "Please restart the server and see if the services start up fine."
RGB_WARNING "Do you want to restart OS ? [y/n]: "
while :; do
read REBOOT_STATUS
if [[ ! "${REBOOT_STATUS}" =~ ^[y,n]$ ]]; then
echo -en "${RGB_DANGER}Input error, please only input 'y' or 'n': "
else
break
fi
done
REBOOT_STATUS=$(echo $REBOOT_STATUS | tr [:upper:] [:lower:])
[ "${REBOOT_STATUS}" == 'y' ] && reboot
}
# 主步骤
main() {
RGB_INFO "1/13 : Customize the profile (color and alias)"
custom_profile
RGB_INFO "2/13 : Time zone adjustment，设置时区"
time_zone
RGB_INFO "3/13 : Disable selinux，禁用 SELinux"
disable_selinux
RGB_INFO "4/13 : Configure Limit IP login，限制 IP 远程访问"
limit_sshIP
RGB_INFO "5/13 : Disable Ctrl+Alt+Del"
disable_cad
if [ "$cansue_bbr" = "Y" ];then
RGB_INFO "6/13 : Enable Google bbr congestion control algorithm，启用 Google BBR 防拥堵，内核版本≥4.9"
open_bbr
else
RGB_INFO "6/13 : 不支持 Google BBR 防拥堵配置，内核版本服务器托管，北京服务器托管，服务器租用 http://www.fwqtg.net
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