Windows 10: OpenSSH - how to make scp use certificates from ssh-agent

Hello. I am using OpenSSH on Windows 11.We are using private key/certificate based authentication not public/private key auth. In Powershell we can use the ssh-add command to add an issued certificate to ssh-agent. For background information we have an issuing authority which gives us short-lived certificates for authentication to our ssh hosts - great article here SSH Security Best Practices using Certificates, 2FA and Bastions goteleport.comOnce added to ssh-agent and entering our passphrase to unlock the private key, we can very simply ssh to a host system usingssh $user@$hostThis i

:)

 

How to : use scp to append public key from linux(client) to windows (server with openssh running) in C:\PROGRAMDATA\ssh\administrators_authorized_keys OR $USERPROFILE:\.ssh\authorized_keys

I am trying to copy a client key from Linux(Ubuntu) to Windows server as an administrator user.
so far i am able to achieve this by using following steps(1-4):
> Note: I am using bash in linux and powershell 7.3.4 in windows as an administrator.
1. Copy the public key from linux client to windows server:
`scp ~/.ssh/public_key.pub windowsUser@windowsMachine:__PROGRAMDATA__/ssh/`
2. ssh into windows server and check if there is `administrators_authorized_keys` file present in `C:\PROGRAMDATA\SSH\`
If not, Create:
`New-Item -Force -Path c:\PROGRAMDATA\ssh\administrators_authorized_keys`
3. Set Permissions for administrators_authorized_keys file:
`icacls C:\PROGRAMDATA\ssh\administrators_authorized_keys /inheritance:r /grant "Administrators:F" /grant "SYSTEM:F"`
4. Append public_key.pub content into administrator_authorized_keys.
`Get-Content C:\ProgramData\ssh\public_key.pub | Add-Content C:\ProgramData\ssh\administrators_authorized_keys`

Now that the `administrators_authorized_keys` file has been created and configured, i am trying to have a different linux client to append its public key to this windows server (with `administrators_authorized_keys` configured) using `scp` in ONE-LINE.
I have tried something like this:
`scp Linux2Win_key.pub Admin@WindowsServer:__ProgramData__/ssh/ ; Get-Content C:\ProgramData\ssh\Linux2Win_key.pub | Add-Content C:\ProgramData\ssh\administrators_authorized_keys`
Public key file is copied but NOT appended to the `administrator_authorized_keys` file. Got an Error:
`-bash: Add-Content: command not found`
`-bash: Get-Content: command not found`
Then i tried this :
`scp Linux2Win_key.pub Admin@WindowsServer:__ProgramData__/ssh/ ; cat __ProgramData__/ssh/Linux2Win_key.pub >> __ProgramData__/ssh/administrators_authorized_keys`
Similar result, Public key file is copied but NOT appended to the `administrator_authorized_keys` file. Got an Error:
`-bash: __ProgramData__/ssh/administrators_authorized_keys: No such file or directory`

Thoughts:
It looks like scp can only copy files and ssh-copy-id don't work in windows despite openssh can be enable and ssh can be used in windows.

If you know any better way (rather than doing manually) to append public key to `authorized_keys` or `administrators_authorized_keys` in windows, please share. Thanks

 

How to : use scp to append public key from linux(client) to windows (server with openssh running) in C:\PROGRAMDATA\ssh\administrators_authorized_keys OR $USERPROFILE:\.ssh\authorized_keys

it seems i was just missing quotes!
When using scp command, after Admin@WindowsServer:, content must be in quotes.
scp Linux2Win_key.pub Admin@WindowsServer:'__ProgramData__/ssh/ ; Get-Content C:\ProgramData\ssh\Linux2Win_key.pub | Add-Content C:\ProgramData\ssh\administrators_authorized_keys'
worked for me. Thanks

 

OpenSSH SSH server from unknown manufacturer

After I got my PC scanned in safe mode, I had issues with booting in to the normal mode, I had to disable all services and enable them one by one until I came across the “OpenSSH SSH server”, and then I decided to leave “OpenSSH SSH server” disabled, I didn’t want to go through the hassle since it looked like the suspicious service.