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Command - sudo

2022-04-23 19:26:00 【Little monster 55】

sudo It's a kind of authority management mechanism , It allows the system administrator to assign reasonable tasks to ordinary users " right ", Let them perform tasks that only super users or other authorized users can complete , such as : Run something like mount,halt,su Orders like that , Or edit some system configuration files , image /etc/mtab,/etc /samba/smb.conf etc. .

1.su

Switching users

Format

 
       # Format 
       
       1)su 
       
       -[l]/--login username
       
       2)su username 
       
       # Don't specify username  The default is root
       
       1 and 2 The difference between :1 After switching users , Also switch to the new user's work environment 
       
       2 After switching users , Do not change the original user's working directory , And other environment variable directories 
      
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command -sudo_ command -sudo

Example

 
       [[email protected] ~]
       
       # su openstack
       
[[email protected] root]
       
       $ pwd
       
/root
       
[[email protected] root]
       
       $ exit
       
       exit
       
[[email protected] ~]
       
       # su - openstack
       
Last login: Sat Apr 
       
       23 
       
       17:44:35 CST 
       
       2022 on pts/0
       
[[email protected] ~]
       
       $ pwd
       
/home/openstack
      
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2.sudo

 
        package :sudo
       
 help :man 
       
       5 sudoers
       
 effect : Authorize the specified user , On the specified host , Run some commands ; If an unauthorized user attempts to use sudo, You will be prompted to contact the administrator 
       
      Provide logs , Record user usage sudo operation 
       
      Provide configuration files for system administrators , Manage user permissions and hosts 
       
      Use a timestamp file to accomplish something like 
       
       " Ticket checking " The system of , The default deposit period is 5min
       
       # adopt visudo Command edit profile , It has the function of grammar checking 
       
 use visudo Command to edit  /etc/sudoers
       
usage: visudo [-chqsV] [-f sudoers]
       
    visudo 
       
       -c 
       
       # Syntax check 
       
    visudo 
       
       -f /etc/sudoers.d/test
      
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2.1. file

 
        The configuration file :/etc/sudoers   /etc/sudoers.d/*
       
 Time stamp file :/var/db/sudo
       
 Log files :/var/log/secure
       
 Profile support : wildcard glob
       
  ？
       
  *
       
  [wxc] 
       
       # Match one of the characters 
       
  [!wxc]
       
  \x 
       
       # escape 
       
  [[alpha]]
       
       # There are two types of profile rules :
       
       1. The alias definition : It's not necessary 
       
       2. Authorization rules : must 
      
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2.2. Authorization rules

 
       user    host    
       
       = (runas)     command
       
 user      Log in to the host  
       
       = ( On behalf of the user )     command 
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       -
       
root    ALL     
       
       =  (ALL)       ALL
       
user:    
       
       # The identity of the person who ran the command 
       
host:    
       
       # Through which hosts 
       
(runas)：
       
       # As which user 
       
command: 
       
       # Which commands to run 
       
       # Example ：
       
wang 
       
       192.168.37
       
       .7
       
       =(root)  /bin/mount /dev/sr0 /mnt
      
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2.3. Alias

 
       #user and runas:
       
    username
       
       #uid
       
    %group_name
       
    %
       
       #gid
       
    user_alias|runas_alias
       
       #host:
       
    ip or hostname
       
    network(/netmask)
       
    host_alias
       
       #command:
       
    command name
       
    directory
       
    sudoedit
       
    Cmnd_Alias
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       --
       
       # There are four types of aliases 
       
    User_Alias
       
    Runas_Alias
       
    Host_Alias
       
    Cmnd_Alias
       
       # Alias format 
       
[A-Z]([A-Z][0-9]_)*
       
       # The alias definition ：
       
Alias_Type 
       
       NAME1
       
       =item1,item2,item3
       
       :NAME2
       
       =item4,item5
       
 Example 1：
       
Student  
       
       ALL
       
       =(ALL)       ALL
       
%wheel  
       
       ALL
       
       =(ALL)       ALL
       
 Example 2：
       
Student  
       
       ALL
       
       =(root)     /sbin/pidof,/sbin/ifconfig
       
%wheel  
       
       ALL
       
       =(ALL)       NOPASSWD:ALL
       
 Example 3：
       
User_Alias 
       
       NETADMIN
       
       = netuser1,netuser2
       
Cmnd_Alias NETCMD 
       
       = /usr/sbin/ip
       
NETADMIN 
       
       ALL
       
       =（root） NETCMD
       
 Example 4：
       
User_Alias 
       
       SYSADER
       
       =wang,mage,%admins
       
User_Alias 
       
       DISKADER
       
       =tom
       
Host_Alias 
       
       SERS
       
       =www.magedu.com,172.16.0.0/24
       
Runas_Alias 
       
       OP
       
       =root
       
Cmnd_Alias 
       
       SYDCMD
       
       =/bin/chown,/bin/chmod
       
Cmnd_Alias 
       
       DSKCMD
       
       =/sbin/parted,/sbin/fdisk
       
SYSADER 
       
       SERS
       
       = SYDCMD,DSKCMD
       
DISKADER 
       
       ALL
       
       =(OP) DSKCMD
       
User_Alias ADMINUSER 
       
       = adminuser1,adminuser2
       
Cmnd_Alias ADMINCMD 
       
       = /usr/sbin/useradd,/usr/sbin/usermod, /usr/bin/passwd [a-zA-Z]*, !/usr/bin/passwd root
       
ADMINUSER 
       
       ALL
       
       =(root) NOPASSWD:ADMINCMD,PASSWD:/usr/sbin/userdel
       
 Example 5：
       
Defaults:wang 
       
       runas_default
       
       =tom
       
wang 
       
       ALL
       
       =(tom,jerry) ALL
       
 Example 6：
       
wang 
       
       192.168.1.6,192.168.1
       
       .8
       
       =(root) /usr/sbin/,!/usr/sbin/useradd
       
 Example 7：
       
wang 
       
       ALL
       
       =(ALL) /bin/cat /var/log/messages*
      
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2.4.sudo command

 
       sudo –i –u wang  Switch identities 
       
       sudo [-u user] COMMAND
       
       -V      
       
       # Display configuration information such as version information 
       
       -u user 
       
       # Think root
       
       -l,ll   
       
       # List the commands available and disabled on the host 
       
       -v      
       
       # Extend the validity of the password 5 minute , Update timestamp 
       
       -k      
       
       # Clear timestamp （1970-01-01）, I need to retype the password next time 
       
       -K      
       
       #-k similar , Also delete the timestamp file 
       
       -b      
       
       # Execute instructions in the background 
       
       -p      
       
       # Change the prompt symbol for asking for the password 
       
 Example ：-p 
       
       "password on %h for user %p:"
      
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