Configure Sudo

	Configure sudo to separate users' duty if some people share privileges.
[1]	Transfer root privilege to a user all.

[root@dlp ~]# visudo # add at the last line: user 'cent' can use all root privilege cent ALL=(ALL) ALL # how to write ⇒ destination host=(owner) command # make sure with user 'cent' [cent@dlp ~]$ /sbin/shutdown -r now shutdown: Need to be root # denied normally [cent@dlp ~]$ sudo /sbin/shutdown -r now Password: # own password The system is going down for reboot NOW!   # just executed

[2]	In addition to the setting [1], set that some commands are not allowed.

[root@dlp ~]# visudo # near line 49: add aliase for the kind of shutdown commands Cmnd_Alias SHUTDOWN = /sbin/halt, /sbin/shutdown, \ /sbin/poweroff, /sbin/reboot, /sbin/init # add ( commands in aliase 'SHUTDOWN' are not allowed ) cent ALL=(ALL) ALL, !SHUTDOWN # make sure with user 'cent' [cent@dlp ~]$ sudo /sbin/shutdown -r now Sorry, user cent is not allowed to execute '/sbin/shutdown -r now' as root on dlp.server.world.   # denied normally

[3]	Transfer some commands with root privilege to users in a group.

[root@dlp ~]# visudo # near line 51: add aliase for the kind of user management comamnds Cmnd_Alias USERMGR = /usr/sbin/useradd, /usr/sbin/userdel, /usr/sbin/usermod, \ /usr/bin/passwd # add at the last %usermgr ALL=(ALL) USERMGR [root@dlp ~]# groupadd usermgr [root@dlp ~]# vi /etc/group # add a user in this group usermgr:x:502: cent # make sure with user 'cent' [cent@dlp ~]$ sudo /usr/sbin/useradd testuser [cent@dlp ~]$ # done normally [cent@dlp ~]$ sudo /usr/bin/passwd testuser Changing password for user testuser. New UNIX password: # set testuser's password Retype new UNIX password: passwd: all authentication tokens updated successfully.

[4]	Transfer a command with root privilege to a user.

[root@dlp ~]# visudo # add at the last cent ALL=(ALL) /usr/sbin/visudo fedora ALL=(ALL) /usr/sbin/useradd, /usr/sbin/userdel, /usr/sbin/usermod, /usr/bin/passwd ubuntu ALL=(ALL) /bin/vi # make sure with user 'cent' [cent@dlp ~]$ sudo /usr/sbin/visudo # possible to open and edit ## Sudoers allows particular users to run various commands as ## the root user, without needing the root password. ## # make sure with user 'fedora' [fedora@dlp ~]$ sudo /usr/sbin/userdel -r testuser [fedora@dlp ~]$ # done normally # make sure with user 'ubuntu' [ubuntu@dlp ~]$ sudo /bin/vi /boot/grub/grub.conf # possible to open and edit # grub.conf generated by anaconda # # Note that you do not have to rerun grub after making changes to this file # NOTICE: You have a /boot partition. This means that

[5]	The logs for sudo are kept in '/var/log/secure', but there are many kind of logs in it. So if you'd like to keep only sudo's log in a file, Set like follows.

[root@dlp ~]#

visudo

# add at the last

Defaults syslog=local1

[root@dlp ~]#

vi /etc/rsyslog.conf

# The authpriv file has restricted access.

# line 42: add

local1.*                                                /var/log/sudo.log

authpriv.*                                             /var/log/secure

[root@dlp ~]#

/etc/rc.d/init.d/rsyslog restart

Shutting down system logger:

[  OK  ]

Starting system logger:

[  OK  ]