Send files over PSSession

Question

I just burned a couple of hours searching for a solution to send files over an active PSSession. And the result is nada, niente. I'm trying to invoke a command on a remote computer over an active session, which should copy something from a network storage. So, basically this is it:

icm -Session $s {
Copy-Item $networkLocation $PCLocation }

Because of the "second hop" problem, I can't do that directly, and because I'm running win server 2003 I cant enable CredSSP. I could first copy the files to my computer and then send/push them to the remote machine, but how? I tried PModem, but as I saw it can only pull data and not push.

Any help is appreaciated.

Answer 1

If it was a small file, you could send the contents of the file and the filename as parameters.

$f="the filename"
$c=Get-Content $f
invoke-command -session $s -script {param($filename,$contents) `
     set-content -path $filename -value $contents} -argumentlist $f,$c

If the file is too long to fit in whatever the limits for the session are, you could read the file in as chunks, and use a similar technique to append them together in the target location

---

PowerShell 5+ has built-in support for doing this, described in David's answer.

Answer 2

This is now possible in PowerShell / WMF 5.0

Copy-Item has -FromSession and -toSession parameters. You can use one of these and pass in a session variable.

eg.

$cs = New-PSSession -ComputerName 169.254.44.14 -Credential (Get-Credential) -Name SQL
Copy-Item Northwind.* -Destination "C:\Program Files\Microsoft SQL Server\MSSQL10_50.SQL2008R2\MSSQL\DATA\" -ToSession $cs

See more examples at here, or you can checkout the official documentation.

Answer 3

I faced the same problem a while ago and put together a proof-of-concept for sending files over a PS Remoting session. You'll find the script here:

https://gist.github.com/791112

#requires -version 2.0

[CmdletBinding()]
param (
    [Parameter(Mandatory=$true)]
    [string]
    $ComputerName,

    [Parameter(Mandatory=$true)]
    [string]
    $Path,

    [Parameter(Mandatory=$true)]
    [string]
    $Destination,

    [int]
    $TransferChunkSize = 0x10000
)

function Initialize-TempScript ($Path) {
    "<# DATA" | Set-Content -Path $Path 
}

function Complete-Chunk () {
@"
DATA #>
`$TransferPath = `$Env:TEMP | Join-Path -ChildPath '$TransferId'
`$InData = `$false
`$WriteStream = [IO.File]::OpenWrite(`$TransferPath)
try {
    `$WriteStream.Seek(0, 'End') | Out-Null
    `$MyInvocation.MyCommand.Definition -split "``n" | ForEach-Object {
        if (`$InData) {
            `$InData = -not `$_.StartsWith('DATA #>')
            if (`$InData) {
                `$WriteBuffer = [Convert]::FromBase64String(`$_)
                `$WriteStream.Write(`$WriteBuffer, 0, `$WriteBuffer.Length)
            }
        } else {
            `$InData = `$_.StartsWith('<# DATA')
        }
    }
} finally {
    `$WriteStream.Close()
}
"@
}

function Complete-FinalChunk ($Destination) {
@"
`$TransferPath | Move-Item -Destination '$Destination' -Force
"@
}

$ErrorActionPreference = 'Stop'
Set-StrictMode -Version Latest

$EncodingChunkSize = 57 * 100
if ($EncodingChunkSize % 57 -ne 0) {
    throw "EncodingChunkSize must be a multiple of 57"
}

$TransferId = [Guid]::NewGuid().ToString()


$Path = ($Path | Resolve-Path).ProviderPath
$ReadBuffer = New-Object -TypeName byte[] -ArgumentList $EncodingChunkSize

$TempPath = ([IO.Path]::GetTempFileName() | % { $_ | Move-Item -Destination "$_.ps1" -PassThru}).FullName
$Session = New-PSSession -ComputerName $ComputerName
$ReadStream = [IO.File]::OpenRead($Path)

$ChunkCount = 0
Initialize-TempScript -Path $TempPath 

try {
    do {
        $ReadCount = $ReadStream.Read($ReadBuffer, 0, $EncodingChunkSize)
        if ($ReadCount -gt 0) {
            [Convert]::ToBase64String($ReadBuffer, 0, $ReadCount, 'InsertLineBreaks') |
                Add-Content -Path $TempPath
        }
        $ChunkCount += $ReadCount
        if ($ChunkCount -ge $TransferChunkSize -or $ReadCount -eq 0) {
            # send
            Write-Verbose "Sending chunk $TransferIndex"
            Complete-Chunk | Add-Content -Path $TempPath
            if ($ReadCount -eq 0) {
                Complete-FinalChunk -Destination $Destination | Add-Content -Path $TempPath
                Write-Verbose "Sending final chunk"
            }
            Invoke-Command -Session $Session -FilePath $TempPath 

            # reset
            $ChunkCount = 0
            Initialize-TempScript -Path $TempPath 
        }
    } while ($ReadCount -gt 0)
} finally {
    if ($ReadStream) { $ReadStream.Close() }
    $Session | Remove-PSSession
    $TempPath | Remove-Item
}

Some minor changes would allow it to accept a session as a parameter instead of it starting a new one. I found the memory consumption on the Remoting service on the destination computer could grow quite large when transferring large files. I suspect PS Remoting wasn't really designed to be used this way.

Answer 4

NET USE allows you to add a local drive letter for the remote system, which then then allows you to use the drive letter in your PSSession, or even without a PSSession. This is helpful if you don't have Powershell v5.0, and even if you do,

You may use the remote machine name or its IP address as part of the remote UNC path and you can specify the username and password credentials on the same line:

    NET USE Z: \\192.168.1.50\ShareName /USER:192.168.1.50\UserName UserPassword  

Another example:

    NET USE Z: \\RemoteSystem\ShareName /USER:RemoteSystem\UserName UserPassword  

OR

    NET USE Z: \\RemoteSystem\ShareName /USER:Domain\UserName UserPassword  

If you don't supply the user credentials on the same line, you will be prompted for them:

>NET USE Z: \\192.168.1.50\ShareName
Enter the user name for '192.168.1.50': 192.168.1.50\UserName
Enter the password for 192.168.1.50: *****
The command completed successfully.

You may remove the drive letter when you're finished with the following:

    NET USE Z: /delete

You can get the full syntax with NET USE /?

>net use /?
The syntax of this command is:

NET USE
[devicename | *] [\\computername\sharename[\volume] [password | *]]
        [/USER:[domainname\]username]
        [/USER:[dotted domain name\]username]
        [/USER:[username@dotted domain name]
        [/SMARTCARD]
        [/SAVECRED]
        [[/DELETE] | [/PERSISTENT:{YES | NO}]]

NET USE {devicename | *} [password | *] /HOME

NET USE [/PERSISTENT:{YES | NO}]  

NET is a standard external .exe command in the system folder and works in Powershell just fine.

Answer 5

$data = Get-Content 'C:\file.exe' -Raw
Invoke-Command -ComputerName 'server' -ScriptBlock { $using:data | Set-Content -Path 'D:\filecopy.exe' }

Don't actually know what the maximum file size limitation is.