SSH Configuration Issue Fixed: Local Authorized Keys No Longer Working

SSH Configuration Issue Fixed: Local Authorized Keys No Longer Working

Published: 21 Jan 2026 by NEMO Team

SSH Configuration Issue Fixed

We have fixed an SSH configuration issue on the login nodes that unintentionally allowed the use of local SSH keys stored in $HOME/.ssh/authorized_keys files.

What happened?

Due to a misconfiguration of the SSH service on the login nodes, SSH keys stored in your local $HOME/.ssh/authorized_keys file were incorrectly accepted in addition to SSH keys configured through our central authentication system at login.bwidm.de. This behavior was never intended and has now been corrected.

Correct authentication methods

As intended, you can access the cluster using:

  1. Password + OTP (One-Time Password)
  2. SSH keys configured in login.bwidm.de

Setting up SSH keys properly

If you need to set up SSH keys for authentication, please follow the official guide:

SSH Key Configuration Guide

This guide will walk you through the process of properly configuring your SSH keys in the central authentication system.

Questions or Issues?

If you have questions about SSH authentication or experience any login issues, please submit a ticket.

NEMO Security SSH Authentication

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