Difference between revisions of "Host keys for Leonhard login nodes"

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==How to remove the old key and add the new one==
 
==How to remove the old key and add the new one==
 
Please remove the old host key with the following command
 
Please remove the old host key with the following command
 +
 +
===Linux, Mac OS X===
  
 
  ssh-keygen -R login.leonhard.ethz.ch
 
  ssh-keygen -R login.leonhard.ethz.ch
 +
 +
===Windows===
 +
If you are using PuTTY, then you can remove the old host keys in the Windows registry.
 +
 +
* Start '''regedit.exe'''
 +
* Navigate to '''HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\SshHostKeys'''
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* Delete the host key for '''login.leonhard.ethz.ch'''
 +
 +
After removing the old host key, you need to login again, compare the displayed host key with the ones published on our wiki and accept the new one in case it is matching.

Latest revision as of 11:06, 29 May 2020

Introduction

When we replace the login nodes, the host keys will change, therefore upon next login you will receive a message

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
SHA256:qdZ/jPc7HODpO2BmCtJxO51jFZVt1t6fjjbtiUAZemI.
Please contact your system administrator.
Add correct host key in /path/to/your/home/.ssh/known_hosts to get rid
of this message.
Offending RSA key in /path/to/your/home/.ssh/known_hosts:252
RSA host key for login.leonhard.ethz.ch has changed and you have requested strict
checking.
Host key verification failed.

Currently valid keys

The MD5 and SHA256 fingerprints of the login nodes' ED25519 and RSA keys are:

ED25519:

SHA256:WKUQ17+G1ri8h+PDS7sLrVXrNyQ2esJnzhxwpOH5Ndk
MD5:c1:dd:c2:0a:b1:f1:0a:f7:bc:b0:33:14:bc:3f:11:f2

ECDSA:

SHA256:3iy5loXQ2VIRRuV37FUid1KcFGGz4daRL3sA34vO5ng
MD5:05:ca:ff:8c:68:08:76:dd:6e:f6:57:01:dd:cf:e0:19

RSA:

SHA256:nNw0ZILGPr9x2NzszoFhd4BBX1cxI8oKSX+Rrj90Lo0
MD5:6e:d3:f0:90:5c:14:76:ca:30:c3:91:c7:48:a2:c2:34

How to remove the old key and add the new one

Please remove the old host key with the following command

Linux, Mac OS X

ssh-keygen -R login.leonhard.ethz.ch

Windows

If you are using PuTTY, then you can remove the old host keys in the Windows registry.

  • Start regedit.exe
  • Navigate to HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\SshHostKeys
  • Delete the host key for login.leonhard.ethz.ch

After removing the old host key, you need to login again, compare the displayed host key with the ones published on our wiki and accept the new one in case it is matching.