Issue

• I noticed a difference in how Red Hat Enterprise Linux (RHEL) versions report the state of users with a * (asterisk) in the password field in /etc/shadow

• In RHEL 4, the ftp user shows an asterisk in the password field and passwd -S ftp shows the following for the ftp user:

[root@host]# grep ^ftp /etc/shadow
ftp:*:14470:0:99999:7:::
[root@host]# passwd -S ftp
Alternate authentication scheme in use.

• In RHEL 5 and 6, the ftp user shows an asterisk in the password field and passwd -S ftp shows the following for the ftp user:

[root@host]# grep ^ftp /etc/shadow
ftp:*:15398:0:99999:7:::
[root@host]# passwd -S ftp
ftp LK 2012-02-27 0 99999 7 -1 (Alternate authentication scheme in use.)

• Is the account locked, or in some other state? What methods can be used to authenticate?

• What does "Alternate authentication scheme in use." mean?