OpenSSH ignores configuration options PasswordAuthentication and KbdInteractiveAuthentication

Ragnar Danneskjold

6/3/23, 11:51 AM

I need to disable SSH password authentication.

I have added the line PasswordAuthentication no to /etc/sshd_config (and copied it 20 times over out of frustration), but after rebooting the machine to make sure everything was reloaded, I am still prompted for a password anyways.

I also need to enable keyboard interactive authentication. Again, adding the appropriate line (KbdInteractiveAuthentication yes) to /etc/sshd_config has no effect.

I have also added the line AuthenticationMethods publickey,keyboard-interactive to /etc/sshd_config; note that I did NOT specify "password" as an authentication method! Still, OpenSSH is requiring a password and not performing keyboard-interactive authentication.

After each change, I ran sudo systemctl sshd reload && sudo systemctl sshd restart, and when that didn't work, I rebooted the machine; still the changes are not being applied.

To make sure that it was using the correct config file, I tried overriding the default (/etc/sshd_config) with itself (see below); I still get the same results even after I execute:

┌──(ragnar@[redacted])-[~]
└─$ sudo sshd -f /etc/ssh/sshd_config
sshd re-exec requires execution with an absolute path
                                                                                                              
┌──(ragnar@[redacted])-[~]
└─$ sudo `which sshd` -f !$

So in addition to trying to provoke me by requiring an absolute path (What a special snowflake you are, OpenSSH), it appears to be simply ignoring certain configuration options.

Is this Agent Smith, or an SSH server? If the latter, is there any way I can get it to behave according to its own specifications, and pay attention to its config file?

Thanks! :)

0 + 0

server

ssh

openssh

David

6/3/23, 3:55 PM

What version of Ubuntu and desktop or server?

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: OpenSSH ignores configuration options PasswordAuthentication and KbdInteractiveAuthentication

TH: OpenSSH ละเว้นตัวเลือกการกำหนดค่า PasswordAuthentication และ KbdInteractiveAuthentication

RO: OpenSSH ignoră opțiunile de configurare PasswordAuthentication și KbdInteractiveAuthentication

RU: OpenSSH игнорирует параметры конфигурации PasswordAuthentication и KbdInteractiveAuthentication.

VI: OpenSSH bỏ qua các tùy chọn cấu hình PasswordAuthentication và KbdInteractiveAuthentication

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