[useradd] ssh impossible even after setting a password

thomas.bucaioni

The steps are:
1. create a user with useradd
2. try to ssh with a fake password three times to have a Permission denied
3. set a password to the user
4. retry to ssh with the right password: it should fail no matter what password is set

The new attemps to connect with ssh fail forever afterwards (under Arch at least...). Is it just me? On two users, I observed the same behaviour.
If the password is set before the ssh attempt or if a fake password is not given three times, then ssh works as expected

coop

I do not know what you are trying to do and this stuff (often involving pam) is often not distribution flexible. Please try on a supported distro which Archlinux is quite definitely not as it is often idiosyncratic as compared to the main supported ones.
(i.e., you lost my attention at "Arch")

thomas.bucaioni

In Ubuntu 20.04.2 LTS (Focal Fossa), the ssh command doesn't work in either cases.
The sshd server is running as shown with systemctl status sshd, but impossible to login with ssh user1@localhost or ssh user1@ipaddress even when the password has been set.
The command su user1 works though

coop

firewall

thomas.bucaioni

It seems it's just Arch: https://wiki.archlinux.org/title/Security#Lock_out_user_after_three_failed_login_attempts

coop

this has been volatile on all recent distributions as Red Hat has removed the pam module for doing this and each distro has now different methods. So we removed mention of it in the courses as being too convoluted