Remote Execution of Powershell

Powershell 2 has some really cool features. One of the features I really like is the remoting portion. Although does not work on Vista, for me I just needed it to work on Win2k3. You will also need powershell installed on that server you are trying to connect to.

Here is some sample code and a helper script (thanks to my co-worker 'AC' for this one) to get it to work:

function ExecuteScriptRemotely($script, $scriptArgs, $server, $cred, $logFile)
{ 
 $cmd = " & { $script } $scriptArgs "

 if($logFile)
 {
     $cmd += " > `"{0}`"" -f $logFile.Replace('"', '')
 }
  
 $encodedCommand = EncodeCommand $cmd
 $commandLine = "powershell -ExecutionPolicy Bypass -EncodedCommand $encodedCommand"
 StartRemoteProcess $commandLine $server $cred
}

function StartRemoteProcess($commandLine, $server, $cred)
{
 if($cred)
 {
     Invoke-WMIMethod -path win32_process -name create -argumentList $commandLine -credential $cred -computerName $server
 }
 else
 {
     Invoke-WMIMethod -path win32_process -name create -argumentList $commandLine -computerName $server
 }
}

function EncodeCommand($expression)
{
 #Convert the command into an encoded command for PowerShell
 $commandBytes = [System.Text.Encoding]::Unicode.GetBytes($expression)
 $encodedCommand = [Convert]::ToBase64String($commandBytes)
 $encodedCommand
}

function CreateCredentials($user, $password)
{
 $password = convertto-securestring $password -asplaintext -force
 New-Object System.Management.Automation.PSCredential $user, $password
}

Here is how you would use it:

$MY_DIR = Split-Path -Path $MyInvocation.MyCommand.Definition -Parent
. (Join-Path $MY_DIR RemHelper.ps1)

# Create c:\bar.txt
$script = '"foo" > "c:\bar.txt"'

# run notepad
$script = 'notepad'

$scriptArgs = $null
$server = "MyServer"
$user = "Admin"
$password = "Password"

$cred = CreateCredentials $user $password
ExecuteScriptRemotely $script $scriptArgs $server $cred "c:\log.txt"