Linux OpenSSH client (Debian Stretch, OpenSSH version 7.4p1)
Windows 10 OpenSSH server (OpenSSH version 9.4p1)
Said Windows 10 OpenSSH server has two different ECDSA public key files loaded on its hard drive:
C:/ProgramData/ssh/ssh_host_ecdsa_key.pub , and
C:/cygwin64/etc/ssh_host_ecdsa_key.pub
I first loaded Cygwin on said Windows 10 server over two years ago. After setting up the SSH “bridge” with said Linux client, things went smoothly during that time, even after a distribution upgrade from Debian Jessie to Debian Stretch on said Linux client.
Last week, I updated OpenSSH on said Linux client. Right about that time, I also noticed that the IP assigned to said Windows 10 server had changed (I don’t know if said IP change was related to said OpenSSH update). During this thrash, I also updated said Windows 10 server’s OpenSSH version via a Cygwin update.
Yesterday, when attempting to SSH from said Linux client to said Windows 10 server (for the first time since the abovementioned recent changes), I got the following message:
The authenticity of host 'xx.xx.xx.xx (xx.xx.xx.xx)' can't be established
ECDSA key fingerprint is xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Are you sure you want to continue connecting (yes/no)?
When investigating the ECDSA public key loaded on said Windows 10 server (to verify a match with the above message), I discovered that the public key loaded in said server’s …ProgramData folder, which had been used by said Linux client for over two years, was no longer being accessed by said Linux client. Instead, said Linux client was wanting to access said server’s ECDSA public key that resides in said server’s …cygwin64 folder!
FYI, on said Windows 10 server, the C:cygwinvarlogsshd.log file is blank and the *C:ProgramDatasshlogs* folder is empty.
What is going on here? Is there any way I can dictate which of said Windows 10 server’s two ECDSA public keys will be “used” by said Linux client?
FYI, these questions initially arose due to this post I made earlier (in particular, check out my answer).
