Add OpenSSH Post

src/content/posts/windows-yubikey-guide/openssh.md

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+title = "Using Yubikey 5 NFC with OpenSSH For Windows"
+tags = ["security","windows","ssh"]
+date = "2022-11-03"
++++
+
+# Table of Contents
+{{< table_of_contents >}}
+
+### Step 0: Preparing Windows 10 for OpenSSH (Importent!)
+
+1. Check if you have OpenSSH already installed.
+```ps
+ssh -V
+```
+if you get the following
+```ps
+❯ ssh -V
+OpenSSH_for_Windows_8.9p1, LibreSSL 3.4.3
+```
+If OpenSSH Version is < 8.1, then you need to remove OpenSSH from your system.<br>
+if OpenSSH Version is 8.2 or greater, Feel free to jump to [Step 2](#step-2-creating-your-ssh-keys)
+
+Most likely, if you are using 8.1, then it was installed from **Add or Remove Optional Features** or **Turn Windows Features on or off**
+So look though these and remove OpenSSH.
+
+### Step 1: Install an Updated version of OpenSSH.
+Run the following command in an Administrator powershell window .
+
+```ps
+winget install Microsoft.OpenSSH.Beta
+```
+To add OpenSSH to your system path, Run the following command.
+```ps
+[Environment]::SetEnvironmentVariable("Path", [Environment]::GetEnvironmentVariable("Path",[System.EnvironmentVariableTarget]::Machine) + ';' + ${Env:ProgramFiles} + '\OpenSSH', [System.EnvironmentVariableTarget]::Machine)
+```
+
+To verify that OpenSSH is setup correctly, run `ssh -V` again
+```ps
+❯ ssh -V
+OpenSSH_for_Windows_8.9p1, LibreSSL 3.4.3
+```
+
+### Step 2: Creating A Multifactor SSH key (This returns a Private keystub + and a .pub)
+**Note: This keeps the Private Key on the Yubikey, The Private file you recieve just tells SSH about the Yubikey and does not contain the private key.**
+```ps
+$keyPath = Join-Path $env:USERPROFILE '/.ssh/' $env:USERNAME
+$keySN = ykman info | Select-String "Serial number:"; $keySN = $keySN.Line.split();
+$keySN = $keySN[2]
+
+ssh-keygen -t ecdsa-sk -f $keyPath-$keySN-yubikey-master -O resident
+```
+
+If this is a new Key, Windows may ask you to setup a pin for the Yubikey.
+***Note: This is your FIDO security pin, it can only be numbers and should be something you can easily remember.***
+
+Now simply upload your public key and you are done.
+
+