linux-centos7 安全优化运维教程-学派吧

前言

centos 越来越普及了，通过一些面板很多小白都可以使用centos、但是安全方面却不行、今天学派吧整理下 centos安全相关的资料
发布出来、供小白学习、

设置

1 修改网卡为eth0

2 更新系统

3 给/etc/rc.local添加执行权限

4 添加用户hequan

5 禁用selinux

6 关闭防火墙安装iptables

7 修改主机名

8 查看并管理服务

9 设置字符集

10 yum

11 配置sshd

12 加大打开文件数的限制（open files）

13 优化内核

14 时间设置

15 man 中文版

16 vim基本设置

1 修改网卡为eth0

cd  /etc/sysconfig/network-scripts/
vim ifcfg-eno16777729
TYPE=Ethernet
BOOTPROTO=static
IPADDR=192.168.1.201
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
DEFROUTE=yes
PEERDNS=yes
PEERROUTES=yes
IPV4_FAILURE_FATAL=no
NAME=eth0
UUID=efd17b9a-a5ab-4c94-be62-d2c32eb48a7e
DEVICE=eth0
ONBOOT=yes
DNS1=202.106.0.20

mv  ifcfg-eno16777729  ifcfg-eth0
vi  /etc/sysconfig/grub
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"
GRUB_CMDLINE_LINUX="net.ifnames=0  biosdevname=0 rhgb quiet"  #添加 net.ifnames=0 biosdevname=0
GRUB_DISABLE_RECOVERY="true"

grub2-mkconfig -o /boot/grub2/grub.cfg      #生成启动菜单
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-3.10.0-327.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-327.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-e8675ae79abd41309dac42388f8d9116
Found initrd image: /boot/initramfs-0-rescue-e8675ae79abd41309dac42388f8d9116.img

reboot

ip addr  或者
yum install net-tools        #默认centos7不支持ifconfig 需要看装net-tools包
ifconfig eth0                #再次查看网卡信息

2 更新系统

yum  update -y

3 给/etc/rc.local添加执行权限

[root@bogon ~]# ll /etc/rc.local
lrwxrwxrwx. 1 root root 13 Feb  6 07:28 /etc/rc.local -> rc.d/rc.local
[root@bogon ~]# ll /etc/rc.d/rc.local
-rw-r--r--. 1 root root 473 May 12  2016 /etc/rc.d/rc.local
[root@bogon ~]# chmod +x /etc/rc.d/rc.local

4 添加用户hequan

[root@bogon ~]# useradd hequan
[root@bogon ~]# echo 123456 | passwd  --stdin  hequan
Changing password for user hequan.
passwd: all authentication tokens updated successfully.
[root@bogon ~]# usermod -G wheel  hequan
[root@bogon ~]# sed -i '6s/^#//g'  /etc/pam.d/su
[root@bogon ~]# grep wheel  /etc/pam.d/su                 #只有WHEEL组的可以su
# Uncomment the following line to implicitly trust users in the "wheel" group.
#auth           sufficient      pam_wheel.so trust use_uid
# Uncomment the following line to require a user to be in the "wheel" group.
auth            required        pam_wheel.so use_uid

扩展:为用户hequan添加sudo，除关机外的其他所有操作：
[root@www ~]# visudo
Cmnd_Alias SHUTDOWN = /sbin/halt, /sbin/shutdown, /sbin/poweroff, /sbin/reboot, /sbin/init
hequan         ALL=(ALL)       ALL,!SHUTDOWN
%wheel         ALL=(ALL)       ALL,!SHUTDOWN    #修改wheel组的权限，禁止关机
Defaults logfile=/var/log/sudo.log

5 禁用selinux

[root@bogon ~]# grep -i  ^selinux   /etc/selinux/config
SELINUX=enforcing
SELINUXTYPE=targeted
[root@bogon ~]# sed -i  '/^SELINUX/s/enforcing/disabled/g' /etc/selinux/config
[root@bogon ~]# grep -i  ^selinux   /etc/selinux/config
SELINUX=disabled
SELINUXTYPE=targeted
[root@bogon ~]# getenforce
Enforcing
[root@bogon ~]# reboot

6 关闭防火墙安装iptables

systemctl   stop   firewalld.service 
systemctl   disable firewalld.service
yum install iptables-services   -y #安装

7修改主机名

[root@bogon ~]# hostnamectl   set-hostname hequan.com
[root@bogon ~]# hostname
xp8.net

8 查看并管理服务

[root@hequan ~]# systemctl  -t  service
[root@hequan ~]# systemctl   list-unit-files  -t service

yum install -y bash-completion        #补全服务名称，退出bash再进就可以

9 设置字符集

[root@hequan ~]# echo $LANG
zh_CN.UTF-8
[root@hequan ~]# vi /etc/locale.conf
LANG="en_US.UTF-8"
[root@hequan ~]# source  /etc/locale.conf

10 yum

yum install gcc cmake bzip2-devel curl-devel db4-devel libjpeg-devel libpng-devel freetype-devel libXpm-devel gmp-devel libc-client-devel openldap-devel unixODBC-devel postgresql-devel sqlite-devel aspell-devel net-snmp-devel libxslt-devel libxml2-devel pcre-devel mysql-devel pspell-devel libmemcached libmemcached-devel zlib-devel  vim wget   lrzsz  tree

安装163源
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
cd  /etc/yum.repos.d/
wget  http://mirrors.163.com/.help/CentOS7-Base-163.repo
yum clean all
yum makecache

其他

yum -y install yum-plugin-priorities   ##安装优先级插件
sed -i -e "s/\]$/\]\npriority=1/g" /etc/yum.repos.d/CentOS-Base.repo  ##设置基本yum源的优先级为1
yum -y install epel-release   ##安装epel源
sed -i -e "s/\]$/\]\npriority=5/g" /etc/yum.repos.d/epel.repo ##设置优先级为5
sed -i -e "s/enabled=1/enabled=0/g" /etc/yum.repos.d/epel.repo ##禁用epel源
yum -y install http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm ##安装rpmforge的源
sed -i -e "s/\]$/\]\npriority=10/g" /etc/yum.repos.d/rpmforge.repo  ##设置优先级为10
sed -i -e "s/enabled = 1/enabled = 0/g" /etc/yum.repos.d/rpmforge.repo ##禁用yum源
使用方法：yum --enablerepo=rpmforge install [Package]

11 配置sshd

sed -i -e '49s/^#//g' /etc/ssh/sshd_config            ##启用49行配置
sed -i -e '49s/yes/no/g' /etc/ssh/sshd_config         ##禁止root使用ssh登录
sed -i -e '129s/#/ /g' /etc/ssh/sshd_config           ##禁止UseDNS 
sed -i -e '129s/yes$/no/g' /etc/ssh/sshd_config
sed -i '/^GSS/s/yes/no/g' /etc/ssh/sshd_config        ##禁用GSSAPI认证加快登录速度

 
systemctl restart sshd                                 ##重新启动服务
systemctl enable  sshd                                 ##设置为开机启动
systemctl status  sshd                                 ##查看状态
● sshd.service - OpenSSH server daemon
   Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; vendor preset: enabled)
   Active: active (running) since 一 2016-06-06 00:16:26 CST; 1min 3s ago

12 加大打开文件数的限制（open files）

ulimit -n
ulimit -a
vi /etc/security/limits.conf
最后添加
* soft nofile 1024000
* hard nofile 1024000
hive   - nofile 1024000
hive   - nproc  1024000



用户进程限制
[root@hequan ~]# sed -i 's#4096#65535#g'   /etc/security/limits.d/20-nproc.conf  #加大普通用户限制  也可以改为unlimited
[root@hequan ~]#  egrep -v "^$|^#" /etc/security/limits.d/20-nproc.conf        
*          soft    nproc     65535
root       soft    nproc     unlimited

reboot

13 优化内核

cat /etc/sysctl.conf
#CTCDN系统优化参数
#关闭ipv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
#决定检查过期多久邻居条目
net.ipv4.neigh.default.gc_stale_time=120
#使用arp_announce / arp_ignore解决ARP映射问题
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.all.arp_announce=2
net.ipv4.conf.lo.arp_announce=2
# 避免放大攻击
net.ipv4.icmp_echo_ignore_broadcasts = 1
# 开启恶意icmp错误消息保护
net.ipv4.icmp_ignore_bogus_error_responses = 1
#关闭路由转发
net.ipv4.ip_forward = 0
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
#开启反向路径过滤
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1
#处理无源路由的包
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0
#关闭sysrq功能
kernel.sysrq = 0
#core文件名中添加pid作为扩展名
kernel.core_uses_pid = 1
# 开启SYN洪水攻击保护
net.ipv4.tcp_syncookies = 1
#修改消息队列长度
kernel.msgmnb = 65536
kernel.msgmax = 65536
#设置最大内存共享段大小bytes
kernel.shmmax = 68719476736
kernel.shmall = 4294967296
#timewait的数量，默认180000
net.ipv4.tcp_max_tw_buckets = 6000
net.ipv4.tcp_sack = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_rmem = 4096        87380   4194304
net.ipv4.tcp_wmem = 4096        16384   4194304
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
#每个网络接口接收数据包的速率比内核处理这些包的速率快时，允许送到队列的数据包的最大数目
net.core.netdev_max_backlog = 262144
#限制仅仅是为了防止简单的DoS 攻击
net.ipv4.tcp_max_orphans = 3276800
#未收到客户端确认信息的连接请求的最大值
net.ipv4.tcp_max_syn_backlog = 262144
net.ipv4.tcp_timestamps = 0
#内核放弃建立连接之前发送SYNACK 包的数量
net.ipv4.tcp_synack_retries = 1
#内核放弃建立连接之前发送SYN 包的数量
net.ipv4.tcp_syn_retries = 1
#启用timewait 快速回收
net.ipv4.tcp_tw_recycle = 1
#开启重用。允许将TIME-WAIT sockets 重新用于新的TCP 连接
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_fin_timeout = 1
#当keepalive 起用的时候，TCP 发送keepalive 消息的频度。缺省是2 小时
net.ipv4.tcp_keepalive_time = 1800
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl = 15
#允许系统打开的端口范围
net.ipv4.ip_local_port_range = 1024    65000
#修改防火墙表大小，默认65536
net.netfilter.nf_conntrack_max=655350
net.netfilter.nf_conntrack_tcp_timeout_established=1200
# 确保无人能修改路由表
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.all.secure_redirects = 0
net.ipv4.conf.default.secure_redirects = 0
sysctl -p  #生效

本身也是搜集网络技术资料，给很多小白也是一个参考、如果有更好的文章、欢迎投稿到我们学派吧、 关注学派 一起学习 加我们QQ群 右上角