深入理解sudo,
[root@cairui ~]# cat /etc/sudoers## Sudoers allows particular users to run various commands as## the root user, without needing the root password. #sudoers允許特定的使用者去執行各種命令以rot的身份,不需要root密碼。#### Examples are provided at the bottom of the file for collections## of related commands, which can then be delegated out to particular## users or groups.## ## This file must be edited with the 'visudo' command.## Host Aliases## Groups of machines. You may prefer to use hostnames (perhaps using ## wildcards for entire domains) or IP addresses instead.# Host_Alias FILESERVERS = fs1, fs2# Host_Alias MAILSERVERS = smtp, smtp2## User Aliases## These aren't often necessary, as you can use regular groups## (ie, from files, LDAP, NIS, etc) in this file - just use %groupname ## rather than USERALIAS# User_Alias ADMINS = jsmith, mikem## Command Aliases## These are groups of related commands...## Networking# Cmnd_Alias NETWORKING = /sbin/route, /sbin/ifconfig, /bin/ping, /sbin/dhclient, /usr/bin/net, /sbin/iptables, /usr/bin/rfcomm, /usr/bin/wvdial, /sbin/iwconfig, /sbin/mii-tool## Installation and management of software# Cmnd_Alias SOFTWARE = /bin/rpm, /usr/bin/up2date, /usr/bin/yum## Services# Cmnd_Alias SERVICES = /sbin/service, /sbin/chkconfig## Updating the locate database# Cmnd_Alias LOCATE = /usr/bin/updatedb## Storage# Cmnd_Alias STORAGE = /sbin/fdisk, /sbin/sfdisk, /sbin/parted, /sbin/partprobe, /bin/mount, /bin/umount## Delegating permissions# Cmnd_Alias DELEGATING = /usr/sbin/visudo, /bin/chown, /bin/chmod, /bin/chgrp ## Processes# Cmnd_Alias PROCESSES = /bin/nice, /bin/kill, /usr/bin/kill, /usr/bin/killall## Drivers# Cmnd_Alias DRIVERS = /sbin/modprobe# Defaults specification## Refuse to run if unable to disable echo on the tty.#Defaults !visiblepw## Preserving HOME has security implications since many programs# use it when searching for configuration files. Note that HOME# is already set when the the env_reset option is enabled, so# this option is only effective for configurations where either# env_reset is disabled or HOME is present in the env_keep list.#Defaults always_set_homeDefaults env_resetDefaults env_keep = "COLORS DISPLAY HOSTNAME HISTSIZE INPUTRC KDEDIR LS_COLORS"Defaults env_keep += "MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE"Defaults env_keep += "LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES"Defaults env_keep += "LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE"Defaults env_keep += "LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSET XAUTHORITY"## Adding HOME to env_keep may enable a user to run unrestricted# commands via sudo.## Defaults env_keep += "HOME"Defaults secure_path = /sbin:/bin:/usr/sbin:/usr/bin## Next comes the main part: which users can run what software on ## which machines (the sudoers file can be shared between multiple## systems).## Syntax:#### user MACHINE=COMMANDS#### The COMMANDS section may have other options added to it.#### Allow root to run any commands anywhere root ALL=(ALL) ALL## Allows members of the 'sys' group to run networking, software, ## service management apps and more.# %sys ALL = NETWORKING, SOFTWARE, SERVICES, STORAGE, DELEGATING, PROCESSES, LOCATE, DRIVERS## Allows people in group wheel to run all commands# %wheel ALL=(ALL) ALL## Same thing without a password# %wheel ALL=(ALL) NOPASSWD: ALL## Allows members of the users group to mount and unmount the ## cdrom as root# %users ALL=/sbin/mount /mnt/cdrom, /sbin/umount /mnt/cdrom## Allows members of the users group to shutdown this system# %users localhost=/sbin/shutdown -h now## Read drop-in files from /etc/sudoers.d (the # here does not mean a comment)#includedir /etc/sudoers.d
注意:修改完(visudo)之後,需要visudo -c檢查一下是否有錯誤。
sudo -l查看使用者擁有的許可權。
1、sudoers設定檔別名介紹
(1)Host Aliases(主機別名)
生產環境中一般不會設定主機別名,一般主機別名不太常用
root ALL=(ALL) ALL #第一個ALL就是主機別名的應用位置
(2)User Aliases(使用者別名)
如果表示使用者組那麼前面加%
root ALL=(ALL) ALL #root就是使用者別名的應用位置
User_Aliases ADMINS = jsmith,mikem
(3)Runas_Alias別名
此別名是指定“使用者身份”,即sudo允許切換到的使用者
root ALL=(ALL) ALL #第二個ALL就是使用者別名的應用位置
Runas_Alias OP = root
(4)Cmnd_Alias(命令別名)
就是定義一個別名,它可以包含一堆命令的內容(一組相關命令的集合)
root ALL=(ALL) ALL
Cmnd_Alias DRIVERS = /sbin/modpro
2、sudo日誌審計
(1)生產環境中日誌方案
a、syslog全部動作記錄審計,這種方法資訊量大,不便查看
b、sudo日誌配置syslog服務進行日誌審查
c、Bastion Host日誌審查
d、bash安裝監視器,記錄使用者使用操作
(2)配合sudo日誌審計
安裝sudo與syslog服務
佈建服務
建立日誌儲存目錄
[root@localhost ~]# mkdir -p /var/log/
查看伺服器版本,6.x為/etc/rsyslog.conf,5.x版本為syslog.conf
上述為rsyslog的設定檔
上述為sudoers的設定檔
測試結果:
[root@localhost ~]# su - cairui[cairui@localhost ~]$ sudo visudo[sudo] password for cairui: visudo: /etc/sudoers.tmp unchanged[cairui@localhost ~]$ cd /tmp/[cairui@localhost tmp]$ touch 123.txt[cairui@localhost tmp]$ sudo llsudo: ll: command not found[cairui@localhost tmp]$ sudo ls -lltotal 0-rw-rw-r-- 1 cairui cairui 0 Feb 12 09:41 123.txt-rw-------. 1 root root 0 Feb 9 09:57 yum.log[cairui@localhost tmp]$ sudo cat /var/log/sudo.log Feb 12 09:41:19 : cairui : TTY=pts/0 ; PWD=/home/cairui ; USER=root ; COMMAND=/usr/sbin/visudoFeb 12 09:41:47 : cairui : TTY=pts/0 ; PWD=/tmp ; USER=root ; COMMAND=/bin/ls -llFeb 12 09:42:12 : cairui : TTY=pts/0 ; PWD=/tmp ; USER=root ; COMMAND=/bin/cat /var/log/sudo.log