有时候，为了满足你的好奇心，在学习一些新东西的同时，更深入地了解事物的工作原理是很有趣的，比如permitrotlogin。它检查UID还是用户名？今天的超级用户Q&A帖子深入一位好奇读者的问题，寻找答案。

今天的问答环节是由SuperUser提供的，SuperUser是Stack Exchange的一个分支，是一个由社区驱动的问答网站分组。

问题

超级用户读者ge0rg想知道permitrotlogin是基于UID还是用户名：

The man page states that PermitRootLogin:

• Specifies whether root can log in using ssh(1).

However, it is not clear if this check is based on the user name (root) or the UID (0). What happens if the root account is renamed to admin? Will admin be able to log in when PermitRootLogin=no? What happens if there are two accounts with UID=0 (i.e. root and admin)? Will either of them be able to log in?

PermitRotLogin是基于UID还是用户名？

答案

超级用户贡献者mtak为我们提供了答案：

It seems the check is done with the UID (tested on OpenSSH_6.7p1 Debian-5+deb8u3, OpenSSL 1.0.1t  3 May 2016):

Set PermitRootLogin to Off:

Make sure a user named admin is created with UID 0:

Make sure the user can be used to log in to the system:

Check to see if we can log in to the system using SSH:

If we set PermitRootLogin back to On:

And try to log in:

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