Windows 10/11 scripts to support ssh-copy-id which is missing in Windows OpenSSH

How to use ssh-copy-id.md

The Windows version of OpenSSH client doesn't include a ssh-copy-id command. I don't know why. If it does one day, then this can be ignored.

NOTE If you have Windows Subsystem for Linux (WSL) installed, you can use the linux version of ssh-copy-id instead. Go to the description at the end of this document.

• Download the file ssh-copy-id.cmd to your Windows PC, or copy and paste its contents.
• Run the script passing your linux ssh information (for example ssh-copy-id.cmd [email protected]). This should work with any Linux platform. Alternatively, if you have experience, you can use the powershell version. ssh-copy-id.ps1. Run the script as powershell .\ssh-copy-id.ps1 [email protected].
• Run the command for each linux account you connect with. You will be prompted for your Linux host password. If you have more than 1 account on any machine, you must do this for each account.

The file name and location of the script is not important but the filename extension must be .cmd

If the public key is already known to the account, it will not be added again.

prerequisite

• You have installed Microsoft's version of OpenSSH Client on your machine. Read this. You do NOT need to install SSH Server. Current versions of Windows 10 and Windows 11 have OpenSSH installed as part of the base Operating System and you do NOT need to install it.
• You have generated a default authorize key. DO THIS ONLY ONCE. You can tell if this is done by looking in your .ssh folder. From command line type dir %userprofile%\.ssh\id_rsa.* If you find 2 files, id_rsa and id_rsa.pub, your default keys have been generated. Otherwise, run ssh-keygen Press enter for all prompts and the default keys will be generated in the correct place. ssh-keygen will warn you it is about to override exiting keys. If it does warn, answer no.

Using Windows Subsystem for Linux

If you have Windows Subsystem for Linux (WSL) installed you can use the linux version of ssh-copy-id. The command prompt version:

pushd %USERPROFILE%\.ssh & wsl ssh-copy-id -i id_rsa -F config <ssh info> & popd

The PowerShell version:

pushd $env:USERPROFILE\.ssh ; wsl ssh-copy-id -i id_rsa -F config <ssh info> ; popd

ssh-copy-id.cmd

@ECHO off
@REM Provide login information
IF "%~1"=="" (
    echo Missing login info as parameter
    echo use %~nx0 user@hostname
    exit /b 2
) else (
    set SSH_TARGET=%1
)
if  not exist "%userprofile%\.ssh\id_rsa" (
    echo "Default authorized key does not exist. Use ssh-keygen"
    exit /b 1
 )
set /p PUBLIC_KEY=<"%USERPROFILE%\.ssh\id_rsa.pub"
echo umask 0077>ssh-copy-id.sh
echo mkdir -p ~/.ssh>>ssh-copy-id.sh
echo grep -q -F ^"%PUBLIC_KEY%^" ~/.ssh/authorized_keys 2^>/dev/null>>ssh-copy-id.sh
echo if [ $? -ne 0 ]>>ssh-copy-id.sh
echo then>>ssh-copy-id.sh
echo    echo ^"%PUBLIC_KEY%^" ^>^> ~/.ssh/authorized_keys >>ssh-copy-id.sh
echo else>>ssh-copy-id.sh
echo    echo Key already exists, no update performed.>>ssh-copy-id.sh
echo fi>>ssh-copy-id.sh
@REM The sed step is to convert crlf to lf for bash - it's fussy
TYPE ssh-copy-id.sh | ssh -o StrictHostKeyChecking=no %SSH_TARGET% "sed 's/\r//' | bash"
echo User %SSH_TARGET% Should be able to login without a password

ssh-copy-id.ps1

<#
    .SYNOPSIS
    Copy ssh public key to remote account

    .DESCRIPTION
    Copies public key to target machine
    Default is .ssh\id_rsa.pub
    See copyright notice at end of script
    If this script won't run, then run this command once
    Set-ExecutionPolicy RemoteSigned CurrentUser
        refer to https://go.microsoft.com/fwlink/?LinkID=135170
 #>
[CmdletBinding()]
param(
    [Parameter(Position = 0, Mandatory = $True)]
    [string]$Target <# SSH compatible Name of Target machine #>,
    [Parameter( Position = 1, Mandatory = $False)]
    [string]$IdentityFile = "id_rsa" <#Identity File, must be in .ssh directory #>,
    [switch]$Save = $False <# Save script used #>
)
$IdentityPath = Join-Path (Join-Path $env:USERPROFILE .ssh) $IdentityFile
if (-not (Test-Path -Path $IdentityPath -PathType Leaf)) {
    Write-Host Key file $IdentityFile does not exist, use ssh-keygen
    exit(1)
}
$PUBLIC_KEY = get-content "${IdentityPath}.pub"
$SCRIPT = @"
#!/bin/bash
#
PUBLIC_KEY="$PUBLIC_KEY"
umask 0077
[ -d ~/.ssh ]||mkdir -p ~/.ssh
[ -f ~/.ssh/authorized_keys ]|| touch ~/.ssh/authorized_keys
grep --quiet --fixed-strings "`$PUBLIC_KEY" ~/.ssh/authorized_keys
if [ `$? -ne 0 ]
then
    echo "`$PUBLIC_KEY" >> ~/.ssh/authorized_keys
else
   echo Key already exists, no update performed.
fi
"@
if ($Save) {
    Set-Content .\ssh-copy-id.sh -Value $SCRIPT
}

# The sed step is to convert crlf to lf for bash - it's fussy
$SCRIPT | ssh $Target -o StrictHostKeyChecking=no "sed 's/\r//' | bash"
if ($?) {
    Write-Output "You should be able to login to $Target without a password using $IdentityFile key"
}
else {
    Write-Host "Could not connect to $Target - Terminating"  -ForegroundColor Red
}
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