OpenSSH Server setup on ArcaOS

[Martin Iturbide]

Hello

Now it is my turn to get Openssh on ArcaOS, so I can access it from a Windows machine.

I have installed OpenSSH
 yum install openssh openssh-server
openssh-8.4p1-5.oc00.pentium4 and openssh-server-8.4p1-5.oc00.pentium4 are installed.

I run with bash

[C:\usr\sbin]bash
bash-5.0# /usr/sbin/sshd -D
sshd: no hostkeys available -- exiting.
bash-5.0#

I created the keys:

ssh-keygen -t rsa -f c:\etc\ssh\ssh_host_rsa_key
ssh-keygen -t dsa -f c:\etc\ssh\ssh_host_dsa_key
ssh-keygen -t ecdsa -f C:\etc\ssh\ssh_host_ecdsa_key
ssh-keygen -t ed25519 -f c:\etc\ssh\ssh_host_ed25519_key

Seems that all keys were created fine.

I run with bash

[C:\usr\sbin]bash
bash-5.0# /usr/sbin/sshd -D
sshd: no hostkeys available -- exiting.
bash-5.0#

So, it still it does not find the keys.
What I'm doing wrong? or what else I'm missing to do?

Thanks in advance.

[Steven Levine]

Try running with the debug option

  sshd -D -d

The extra output might help.

[Martin Iturbide]

Hello

Thanks for the feedback.

Just right now I tried a different approach

It was giving me this issue.

[C:\]C:\usr\sbin\sshd.exe -d
debug1: sshd version OpenSSH_8.4, OpenSSL 3.4.6 9 Jun 2026
debug1: Unable to load host key "/@unixroot/etc/ssh/ssh_host_rsa_key": incorrect
 passphrase supplied to decrypt private key
debug1: Unable to load host key: /@unixroot/etc/ssh/ssh_host_rsa_key
debug1: Unable to load host key "/@unixroot/etc/ssh/ssh_host_ecdsa_key": incorre
ct passphrase supplied to decrypt private key
debug1: Unable to load host key: /@unixroot/etc/ssh/ssh_host_ecdsa_key
debug1: Unable to load host key "/@unixroot/etc/ssh/ssh_host_ed25519_key": incor
rect passphrase supplied to decrypt private key
debug1: Unable to load host key: /@unixroot/etc/ssh/ssh_host_ed25519_key
sshd: no hostkeys available -- exiting.

I'm guessing that since I created the keys with a password, you need to put the password somewhere I don't know.

I was recommended to delete the keys and try again

[C:\ETC\SSH]del ssh-host*.*

I tried this way to generate the keys

[C:\]ssh-keygen -A
ssh-keygen: generating new host keys: RSA DSA ECDSA ED25519

Run again the server.

[C:\]C:\usr\sbin\sshd.exe -d
debug1: sshd version OpenSSH_8.4, OpenSSL 3.4.6 9 Jun 2026
debug1: private host key #0: ssh-rsa SHA256:ByRtqG4qVTacOtWIQuyYOhTIdcmNO4WJ2KAc
fFxlhgo
debug1: private host key #1: ecdsa-sha2-nistp256 SHA256:9sKXxk5sKlu7mEI2we4vVafW
6KzxluyVQkNVbBOluuw
debug1: private host key #2: ssh-ed25519 SHA256:4TBdBd8NgO1jewYEb36JsczrlVlcY+On
VHSsGFPpzo4
debug1: rexec_argv[0]='C:\\usr\\sbin\\sshd.exe'
debug1: rexec_argv[1]='-d'
debug1: Bind to port 22 on 0.0.0.0.
Server listening on 0.0.0.0 port 22.

The server runs.

Now I don't know why it says the 0.0.0.0, and I have to check how to manage the users.

Regards

[David McKenna]

Martin,

 I have been looking at doing this too and have noticed that in the file '\etc\ssh\sshd_config' you have to specify your 'ListenAddress' to the server IP address or else it defaults to 0.0.0.0. Thanks for the tip on creating the keys.

Regards,

[Steven Levine]

Good to see that the debug log revealed the source of the problem.  You did not mention that you created the keys with a passphrase.  I'm a bit surprised that sshd did not prompt for the passphrase.  Perhaps it is a build nit or maybe the behavior has changed over the years.

In the past, I've used ssh-agent to cache and supply the passphrase when required.

[Martin Iturbide]

Hello

I made progress, but I still need to know where to register the users and passwords for the people that will login.
Any ideas?

Regards

[Andi B.]

Hello

I made progress, but I still need to know where to register the users and passwords for the people that will login.
Any ideas?

Regards

Usually I copy the users key with the ssh-copy-id from the client to the server. For this the server has (temporary) allow login via password. We have a .cmd or shell script ported which IIRC worked for me after I discovered that we have it and run it from the directory it resides. Something like 'ssh-copy-id -i ~/.ssh/mykey user@host' (see https://www.ssh.com/academy/ssh/copy-id).

Problem is we usually don't have passwords on OS/2. And I'm not sure ~/ works as link to your home directory. So you use better full path here.

The other probably better way is to copy your own .pub key to the server f.i. via ftp or samba or USB-stick and insert it manually in the authorized_keys file at the server.

I've played with different SSH versions and think I created a topic here. Remember to use the debug option(s) when trying to connect. ssh -v serverip or ssh -v username@serverip.

You usually don't configure user/password on the server as these are the regular Linux users/passwords. I don't know how to configure user/password on OS/2 server. I think I ever used keys to connect instead user/password.

[Steven Levine]

Nickk's openssh port supported password authentication via his Security/2 implementation.

A quick look at the Netlabs openssh sources, indicates that password access might not be enabled in the build.  It might be worth posting an issue at https://github.com/bitwiseworks/openssh-portable.git and asking if this is the case.

[Andi B.]

I now remember at the time I played with SSH server on OS/2 I also played with klusrmgr (rpm). It says that it's outdated and you should use the Samba password manager instead. But for some reason the Samba one didn't work for me.

Anyway when Steven says password is not enabled then not worth to play with this. But there are two different password things - one thing is if the OS/2 server supports it. A different thing is if you can log into a Linux server with our SSH client with password. IIRC this one worked. Especially when using SSH to connect to a git repository (on Linux). Problem was sometimes I didn't see the message from the server to enter the password now. Guessing and typing blindly worked sometimes. But this behavior was different with different SSH versions. But as you specifically want the SSH server part running on OS/2 this maybe not relevant to you.

If I understand Dmitriy correct then he has a setup with OS/2 SSH server. So it should work. At least with manually adding to authorized_keys.

[Steven Levine]

For us SAMBA passwords in no way related SSH passwords.

To be clear I did not say that password access was not enabled.  What I said was when I scanned the code it was not obvious whether or not it was disabled.

Using authorized-keys eliminates the need to provide an account password to the ssh server when connecting.  The ssh server logs you into your account after it authenticates you via the keys.

If you don't have authorized-keys setup, you can login to your account on the server via your userid and password defined on the server if the ssh server is configured to allow password logins.

Have you tested password access to any server using the most recent netlabs ssh client build?