max password is blank

Linux and Unix-Like Linux
1

Hi All,

I have this userid:

[root@123server456 ~]# cat /etc/shadow | grep mysql
mysql:$1$O12345678901234/.:123456:0::14:::

Max password expiration is blank. What does it mean?

If it's like this below
mysql:$1$O12345678901234/.:123456:0:99999:14:::
then there's no expiration.

Thanks in advance for any comments you may add.

Best regards.

2

This is a good question, because in fact, the pam_unix authentication module and corresponding helper program chkpwd are very unclear on how they handle things. If you do look at the pam_unix documentation (here, you'll find it has something like "broken_shadow", which allows the module to "succeed" if something in the shadow file is not right, such as an empty expiration time.

However, it seems like it worked even with "broken_shadow" disabled and an empty expiration time. The only way to know for sure is to look at the source code of the modules.