linux-centos7 安全优化运维教程

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、今天名铺123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 

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