OpenSSH : SSH Key-Pair Authentication2024/11/27

PowerShell
Copyright (C) Microsoft Corporation. All rights reserved.

# for common users, it's [authorized_keys]
PS C:\Users\Administrator> Get-Content C:\ProgramData\ssh\sshd_config | Select-String -Pattern "^AuthorizedKeysFile" 

AuthorizedKeysFile      .ssh/authorized_keys


# for [Administrators] group, it's [administrators_authorized_keys]
PS C:\Users\Administrator> Get-Content C:\ProgramData\ssh\sshd_config -Tail 3 

Match Group administrators
       AuthorizedKeysFile __PROGRAMDATA__/ssh/administrators_authorized_keys

PowerShell
Copyright (C) Microsoft Corporation. All rights reserved.

# create key-pair
PS C:\Users\serverworld> ssh-keygen 
Generating public/private ed25519 key pair.
Enter file in which to save the key (C:\Users\Serverworld/.ssh/id_ed25519):   # Enter or input changes if you want
Created directory 'C:\\Users\\Serverworld/.ssh'.
Enter passphrase (empty for no passphrase):   # set passphrase (if set no passphrase, Enter with empty)
Enter same passphrase again:
Your identification has been saved in C:\Users\Serverworld/.ssh/id_ed25519
Your public key has been saved in C:\Users\Serverworld/.ssh/id_ed25519.pub
The key fingerprint is:
SHA256:5L+wo4E3Q2oHwpyKAa8l54AjEyFcijQX3Q7C+ZAJo44 serverworld@RX-7
The key's randomart image is:

PS C:\Users\serverworld> cd .ssh 
PS C:\Users\serverworld\.ssh> ls 

    Directory: C:\Users\Serverworld\.ssh


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a----        11/26/2024   4:59 PM            464 id_ed25519
-a----        11/26/2024   4:59 PM             99 id_ed25519.pub

# rename public-key
PS C:\Users\serverworld\.ssh> mv id_ed25519.pub authorized_keys 
PS C:\Users\serverworld\.ssh> ls 

    Directory: C:\Users\Serverworld\.ssh


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a----        11/26/2024   4:59 PM             99 authorized_keys
-a----        11/26/2024   4:59 PM            464 id_ed25519

PowerShell
Copyright (C) Microsoft Corporation. All rights reserved.

# create [.ssh] folder if it does not exist
PS C:\Users\serverworld> mkdir .ssh 
PS C:\Users\serverworld> cd .ssh 

# transfer the private key to the local ssh directory
PS C:\Users\serverworld\.ssh> scp Serverworld@10.0.0.101:'C:\Users\serverworld\.ssh\id_ed25519' ./ 
The authenticity of host '10.0.0.101 (10.0.0.101)' can't be established.
ED25519 key fingerprint is SHA256:cPH/QhY3fA+xz3z1guTIwl2emYhlzsTXNGzdS2nh5wQ.
This key is not known by any other names.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '10.0.0.101' (ED25519) to the list of known hosts.
Serverworld@10.0.0.101's password:
id_ed25519

PS C:\Users\serverworld\.ssh> ls 

    Directory: C:\Users\serverworld\.ssh


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a----        2024/11/27     10:36            444 id_ed25519
-a----        2024/11/27     10:36            831 known_hosts
-a----        2024/11/27     10:35             93 known_hosts.old

# verify access
PS C:\Users\serverworld\.ssh> ssh Serverworld@10.0.0.101 hostname 
Enter passphrase for key 'C:\Users\serverworld/.ssh/id_ed25519':   # passphrase if you set
RX-7   # authenticated

PowerShell
Copyright (C) Microsoft Corporation. All rights reserved.

# change to [PasswordAuthentication no]
PS C:\Users\Administrator> (Get-Content C:\ProgramData\ssh\sshd_config).Replace("#PasswordAuthentication yes","PasswordAuthentication no") | Set-Content C:\ProgramData\ssh\sshd_config 
PS C:\Users\Administrator> echo 'KbdInteractiveAuthentication no' | Add-Content C:\ProgramData\ssh\sshd_config -Encoding UTF8 

PS C:\Users\Administrator> Restart-Service -Name "sshd"