Using PowerShell credentials without being prompte

Question

I'd like to restart a remote computer that belongs to a domain. I have an administrator account but I don't know how to use it from powershell.

I know that there is a Restart-Computer cmdlet and that I can pass credential but if my domain is for instance mydomain, my username is myuser and my password is mypassword what's the right syntax to use it?

I need to schedule the reboot so I don't have to type the password.

Answer 1

The problem with Get-Credential is that it will always prompt for a password. There is a way around this however but it involves storing the password as a secure string on the filesystem.

The following article explains how this works:

Using PSCredentials without a prompt

In summary, you create a file to store your password (as an encrypted string). The following line will prompt for a password then store it in c:\mysecurestring.txt as an encrypted string. You only need to do this once:

read-host -assecurestring | convertfrom-securestring | out-file C:\mysecurestring.txt

Wherever you see a -Credential argument on a PowerShell command then it means you can pass a PSCredential. So in your case:

$username = "domain01\admin01"
$password = Get-Content 'C:\mysecurestring.txt' | ConvertTo-SecureString
$cred = new-object -typename System.Management.Automation.PSCredential `
         -argumentlist $username, $password

$serverNameOrIp = "192.168.1.1"
Restart-Computer -ComputerName $serverNameOrIp `
                 -Authentication default `
                 -Credential $cred
                 <any other parameters relevant to you>

You may need a different -Authentication switch value because I don't know your environment.

Answer 2

Solution

$userName = 'test-domain\test-login'
$password = 'test-password'

$pwdSecureString = ConvertTo-SecureString -Force -AsPlainText $password
$credential = New-Object -TypeName System.Management.Automation.PSCredential `
    -ArgumentList $userName, $pwdSecureString

For Build Machines
In the previous code replace user name and password values by secret ("hidden from logs") environment variables of your build-machine

Test results by

'# Results'
$credential.GetNetworkCredential().Domain
$credential.GetNetworkCredential().UserName
$credential.GetNetworkCredential().Password

and you'll see

# Results
test-domain
test-login
test-password

Answer 3

Regarding storing credentials, I use two functions(that are normally in a module that is loaded from my profile):

#=====================================================================
# Get-MyCredential
#=====================================================================
function Get-MyCredential
{
param(
$CredPath,
[switch]$Help
)
$HelpText = @"

    Get-MyCredential
    Usage:
    Get-MyCredential -CredPath `$CredPath

    If a credential is stored in $CredPath, it will be used.
    If no credential is found, Export-Credential will start and offer to
    Store a credential at the location specified.

"@
    if($Help -or (!($CredPath))){write-host $Helptext; Break}
    if (!(Test-Path -Path $CredPath -PathType Leaf)) {
        Export-Credential (Get-Credential) $CredPath
    }
    $cred = Import-Clixml $CredPath
    $cred.Password = $cred.Password | ConvertTo-SecureString
    $Credential = New-Object System.Management.Automation.PsCredential($cred.UserName, $cred.Password)
    Return $Credential
}

And this one:

#=====================================================================
# Export-Credential
# Usage: Export-Credential $CredentialObject $FileToSaveTo
#=====================================================================
function Export-Credential($cred, $path) {
      $cred = $cred | Select-Object *
      $cred.password = $cred.Password | ConvertFrom-SecureString
      $cred | Export-Clixml $path
}

You use it like this:

$Credentials = Get-MyCredential (join-path ($PsScriptRoot) Syncred.xml)

If the credential file doesnt exist, you will be prompted the first time, at that point it will store the credentials in an encrypted string inside an XML file. The second time you run that line, the xmlfile is there and will be opened automatically.

Answer 4

Here are two ways you could do this, if you are scheduling the reboot.

First you could create a task on one machine using credentials that have rights needed to connect and reboot another machine. This makes the scheduler responsible for securely storing the credentials. The reboot command (I'm a Powershell guy, but this is cleaner.) is:

SHUTDOWN /r /f /m \\ComputerName

The command line to create a scheduled task on the local machine, to remotely reboot another, would be:

SCHTASKS /Create /TN "Reboot Server" /TR "shutdown.exe /r /f /m \\ComputerName" /SC ONCE /ST 00:00 /SD "12/24/2012" /RU "domain\username" /RP "password"

I prefer the second way, where you use your current credentials to create a scheduled task that runs with the system account on a remote machine.

SCHTASKS /Create /TN "Reboot Server" /TR "shutdown.exe /r /f" /SC ONCE /ST 00:00 /SD "12/24/2012" /RU SYSTEM /S ComputerName

This also works through the GUI, just enter SYSTEM as the user name, leaving the password fields blank.

Answer 5

read-host -assecurestring | convertfrom-securestring | out-file C:\securestring.txt
$pass = cat C:\securestring.txt | convertto-securestring
$mycred = new-object -typename System.Management.Automation.PSCredential -argumentlist "test",$pass
$mycred.GetNetworkCredential().Password

Be very careful with storing passwords this way... it's not as secure as ...

Answer 6

why dont you try something very simple?

use psexec with command 'shutdown /r /f /t 0' and a PC list from CMD.