[root@localhost ~]# history //查看历史命令
1 vim /ect/sysconfig/network-scripts/ifcfg-ens33
2 vim /etc/sysconfig/network-scripts/ifcfg-ens33
3 vim /ect/sysconfig/network-scripts/ifcfg-ens33
4 vim /ect/sysconfig/network-scripts/ifcfg-ens33
5 vim /ect/sysconfig/netwok-scripts/ifcfg-ens33
6 vim /etc/sysconfig/network-scripts/ifcfg-ens-33
7 vim /etc/sysconfig/network-scirpts/ifcfg-ens33
8 vim /etc/sysconfig/network-scripts/ifcfg-ens33
9 vim /etc/sysconfig/network-scirpts/ifcfg-ens33
10 vim /etc/sysconfig/network-scripts/ifcfg-ens33
11 service network restart
12 ifconfig
13 chattr +i /etc/passwd /etc/shadow
14 lsattr /etc/passwd /etc/shadow
15 chattr -i /etc/passwd /etc/shadow
16 lsattr /etc/passwd /etc/shadow
17 chattr +i /etc/passwd/ /etc/shadow
18 chattr +i /etc/passwd /etc/shadow
19 lsattr
20 lsattr /etc/passwd /etc/shadow
21 useradd siti
22 chattr -i /etc/passwd /etc/shadow
23 lsattr /etc/passwd /etc/shadow
24 useradd siti
25 passwd siti
26 history
[root@localhost ~]# history -c //清除历史命令
[root@localhost ~]# history //查看历史命令
1 history
减少记录的命令条数
vim /etc/profile ：系统环境变量配置文件今日其中更改历史命令记录条数
source /etc/profile：使更改的配置生效
[root@localhost ~]# vim /etc/profile
[root@localhost ~]# history //查看历史命令，这个时候设置并没有生效
1 history
2 vim /etc/profile
3 history
[root@localhost ~]# source /etc/profile //输入命令，使更改的配置生效
[root@localhost ~]# history //再次查看历史命令
4 history //只显示一条命令
闲置自动注销
vim /etc/profile 配置文件中编辑添加闲置注销条目，并设定自动注销时间
export TMOUT=时间（单位：秒）：设定限制注销时间条目
[root@localhost ~]# vim /etc/profile //进入编辑配置文件
pathmunge /usr/local/sbin after
pathmunge /usr/sbin after
# /etc/profile
# System wide environment and startup programs, for login setup
# Functions and aliases go in /etc/bashrc
# It's NOT a good idea to change this file unless you know what you
# are doing. It's much better to create a custom.sh shell script in
...//省略部分内容...
fi
fi
done
unset i
unset -f pathmunge
export TMOUT=60 //添加设定条目
~
:wq //保存退出
[root@localhost ~]# source /etc/profile //输入命令，使更添加的条目生效
[root@localhost ~]# vim /etc/pam.d/su
#%PAM-1.0
auth sufficient pam_rootok.so
# 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
auth substack system-auth
auth include postlogin
account sufficient pam_succeed_if.so uid = 0 use_uid quiet
account include system-auth
password include system-auth
session include system-auth
session include postlogin
session optional pam_xauth.so
[root@localhost ~]# vim /etc/pam.d/su
#%PAM-1.0
auth sufficient pam_rootok.so
# 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 //去掉此条目前# 开启pam认证
auth substack system-auth
auth include postlogin
account sufficient pam_succeed_if.so uid = 0 use_uid quiet
account include system-auth
password include system-auth
session include system-auth
session include postlogin
session optional pam_xauth.so
[root@localhost ~]# su - sun //切换至sun用户
上一次登录：三 8月 28 16:22:56 CST 2019pts/0 上
[sun@localhost ~]$ su - root //切换到root用户
密码：
上一次登录：三 8月 28 16:23:23 CST 2019pts/0 上
[root@localhost ~]# su - siti //切换到siti用户
上一次登录：三 8月 28 16:23:14 CST 2019pts/0 上
[siti@localhost ~]$ su - root //切换到root用户
密码：
su: 拒绝权限 //无法切换，拒绝访问
[siti@localhost ~]$
sudo提权
通过 su 命令可以非常方便地切换为另一个用户，但前提条件是必须知道目标用户的登录密码。对于生产环境中的 Linux 服务器，每多一个人知道特权密码，其安全风险也就增加一分。这个时候可以使用 sudo 命令就提升执行权限。不过，需要由管理员预先进行授权，指定允许哪些用户以超级用户（或其他普通用户）的身份来执行哪些命令。
[root@localhost ~]# vim /etc/sudoers
...//省略部分内容...
## Sudoers allows particular users to run various commands as
## the root user, without needing the root password.
#ar groups
## (ie, from files, LDAP, NIS, etc) in this file - just use %groupname
## rather than USERALIAS
# User_Alias ADMINS = jsmith, mikem
siti localhost = /sbin/ifconfig //输入授权记录，注意：命令路径要写全
## Command Aliases
...//省略部分内容...
## Installation and management of software
# Cmnd_Alias SOFTWARE = /bin/rpm, /usr/bin/up2date, /usr/bin/yum
## Services
@ @
:w! //强制保存，在输入：q退出
[root@localhost ~]# cd /mnt/john-1.8.0/run //进入run目录
[root@localhost run]# ls //查看执行确定可执行脚本
ascii.chr john lm_ascii.chr makechr relbench unique
digits.chr john.conf mailer password.lst unafs unshadow
[root@localhost run]# ./john /etc/shadow //执行john软件检查用户密码存放目录shadow目录
Loaded 2 password hashes with 2 different salts (crypt, generic crypt(3) [?/64])
Press 'q' or Ctrl-C to abort, almost any other key for status
123123 (root) //成功检测出用户弱口令密码
123123 (sun)
2g 0:00:00:15 100% 2/3 0.1332g/s 420.1p/s 452.0c/s 452.0C/s leslie..boston
Use the "--show" option to display all of the cracked passwords reliably
Session completed
[root@localhost run]# nmap -sT 127.0.0.1 //检测本地开放的TCP端口
Starting Nmap 6.40 ( http://nmap.org ) at 2019-09-02 03:19 CST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00082s latency).
Not shown: 996 closed ports
PORT STATE SERVICE
22/tcp open ssh
25/tcp open smtp
111/tcp open rpcbind
631/tcp open ipp
Nmap done: 1 IP address (1 host up) scanned in 0.06 seconds
[root@localhost run]# nmap -sU 127.0.0.1 //检测本地开放的TCP端口
Starting Nmap 6.40 ( http://nmap.org ) at 2019-09-02 03:21 CST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000049s latency).
Not shown: 997 closed ports
PORT STATE SERVICE
68/udp open|filtered dhcpc
111/udp open rpcbind
5353/udp open|filtered zeroconf
Nmap done: 1 IP address (1 host up) scanned in 48.95 seconds
[root@localhost run]# nmap -sP 192.168.31.12 //检测地址主机是否存活
Starting Nmap 6.40 ( http://nmap.org ) at 2019-09-02 03:24 CST
Nmap scan report for 192.168.31.12
Host is up (0.00067s latency).
Nmap done: 1 IP address (1 host up) scanned in 0.17 seconds
[root@localhost run]# nmap -sT 192.168.31.12 //检测目标地址主机开放的TCP端口
Starting Nmap 6.40 ( http://nmap.org ) at 2019-09-02 03:30 CST
Nmap scan report for 192.168.31.12
Host is up (0.0019s latency).
Not shown: 995 filtered ports
PORT STATE SERVICE
135/tcp open msrpc
139/tcp open netbios-ssn
443/tcp open https
445/tcp open microsoft-ds
902/tcp open iss-realsecure
Nmap done: 1 IP address (1 host up) scanned in 9.32 seconds
