今天没事，做了个小实验，普通用户切换如何省略密码
省略密码验证（下面是那个具体的实验内容）
很简单，只需把/etc/passwd中的root:x:0:0:root:/root:/bin/bash，改为root::0:0:root:/root:/bin/bash，就可以了，就是去掉了里面的x，这样root用户就不用密码了。其他用户也一样。
[root@localhost ~]# useradd user01 [root@localhost ~]# passwd user01 Changing password for user user01. New UNIX password: BAD PASSWORD: it is based on a dictionary word Retype new UNIX password: passwd: all authentication tokens updated successfully. [root@localhost ~]# useradd user02 [root@localhost ~]# passwd user02 Changing password for user user02. New UNIX password: BAD PASSWORD: it is based on a dictionary word Retype new UNIX password: passwd: all authentication tokens updated successfully.
创建完用户名密码后，现在切换下用户
[root@localhost ~]# su - user01 [user01@localhost ~]$ whoami user01 [user01@localhost ~]$ su - user02 口令： [user02@localhost ~]$
输入用户口令后，才能切换
[user02@localhost ~]$ su - 口令： [root@localhost ~]# [root@localhost ~]# vim /etc/passwd
将x去掉
user01:x:502:502::/home/user01:/bin/bash user02:x:503:503::/home/user02:/bin/bash
修改为如下格式
user01::502:502::/home/user01:/bin/bash user02::503:503::/home/user02:/bin/bash
保存后再进行切换实验，
[root@localhost ~]# su - user01 [user01@localhost ~]$ whoami user01 [user01@localhost ~]$ su - user02 [user02@localhost ~]$ whoami user02 [user02@localhost ~]$
恭喜您，现在可以实现无密码切换用户
原文：http://402753795.blog.51cto.com/10788998/1770284