Powershell Encoding passing value to WmiMethod - powershell

Question

so, I have been scripting some tasks for HP Bios's. There is a Wmi Namespace called HPBIOS_BIOSSettingInterface. It essentially has one methond SetBIOSSetting("Property","Value","CurrentSetupPassword"). The older HP systems only support KBD Encoding, which I wrote a function to encode a string with KDB values, can be found here: http://thomas-malkewitz.webnode.com/news/convert-tokbdstring/ and when setting the setup password value with this encoding, it works, but with new HPs, it only supports UTF-16 (I cannot find if its Big or Little, but have tried both). I keep getting errors when doing this. So, my question, is how can I encoded a string value and pass it to this method. I cannot figure this out for the life of me. here is my function:
<#
.Synopsis
Sets the Setup Password on an HP Bios.
.DESCRIPTION
This function can be used to set a password on the Bios, it can also be used to clear the password, the current password is needed to change the value.
If a new value is being set, and not cleared, it must be between 8 and 30 characters.
.EXAMPLE
Set-HpSetupPassword -NewSetupPassword "MyNewPassword"
.EXAMPLE
Set-HpSetupPassword -ComputerName "mycomputer.mydomain.org" -NewSetupPassword " " -CurrentSetupPassword "MyCurrentPassword"
.EXAMPLE
Set-HpSetupPassword -NewSetupPassword "MyNewSetupPassword" -CurrentSetupPassword "MyCurrentPassword"
.LINKS
https://github.com/necromorph1024/HPTpmAndBitLocker
#>
function Set-HpSetupPassword
{
[CmdletBinding()]
[OutputType([void])]
Param
(
# ComputerName, Type string, System to set Bios Setup Password.
[Parameter(Mandatory=$false,
Position=0)]
[string]
$ComputerName=$env:COMPUTERNAME,
# NewSetupPassword, Type string, The value of the password to be set. The password can be cleared by using a space surrounded by double quotes, IE: " ".
[Parameter(Mandatory=$true,
Position=1)]
[string]
$NewSetupPassword,
# CurrentSetupPassword, Type string, The value of the current setup password.
[Parameter(Mandatory=$false,
Position=2)]
[AllowEmptyString()]
[string]
$CurrentSetupPassword
)
Begin
{
if (!(Test-Connection -ComputerName $ComputerName -Quiet -Count 2))
{
throw "Unable to connect to $ComputerName. Please ensure the system is available."
}
try
{
$manufacturer = Get-WmiObject -Class Win32_ComputerSystem -Namespace "root\CIMV2" -Property "Manufacturer" -ComputerName $ComputerName -ErrorAction Stop
if ($manufacturer.Manufacturer -ne "Hewlett-Packard")
{
throw "Computer Manufacturer is not of type Hewlett-Packard. This cmdlet can only be used on Hewlett-Packard systems."
}
}
catch
{
throw "Unable to connect to the Win32_ComputerSystem WMI Namespace, verify the system is avaialbe and you have the permissions to access the namespace."
}
}
Process
{
if (-not([String]::IsNullOrWhiteSpace($NewSetupPassword)))
{
if (($NewSetupPassword.Length -lt 8) -or ($NewSetupPassword.Length -gt 30))
{
throw "The Password Values must be be between 8 and 30 characters if not clearing the password."
}
}
$hpBios = Get-WmiObject -Class HP_BiosSetting -Namespace "root\HP\InstrumentedBIOS" -ComputerName $ComputerName -ErrorAction Stop
$hpBiosSettings = Get-WmiObject -Class HPBIOS_BIOSSettingInterface -Namespace "root\HP\InstrumentedBIOS" -ComputerName $ComputerName -ErrorAction stop
if (($hpBios | Where-Object { $_.Name -eq "Setup Password"}).SupportedEncoding -eq "kbd")
{
if (-not([String]::IsNullOrEmpty($NewSetupPassword)))
{
$NewSetupPassword="<kbd/>"+(Convert-ToKbdString -UTF16String $NewSetupPassword)
}
if (-not([String]::IsNullOrEmpty($CurrentSetupPassword)))
{
$CurrentSetupPassword="<kbd/>"+(Convert-ToKbdString -UTF16String $CurrentSetupPassword)
}
}
$hpBiosSettings.SetBIOSSetting("Setup Password",$NewSetupPassword,$CurrentSetupPassword)
}
}
It keeps return 6 which is access denied, which is what I was getting with the older bios's until I created that Convert-KbdString method. I know the password im using is right. But I don't know what encoding is being sent to the WmiMethod. Thanks for any help
here is the GitHub Repo: https://github.com/necromorph1024/HpTpmAndBitLocker

Answer 1

.NET Strings are in the Unicode encoding, according to the documentation for the String class.
http://msdn.microsoft.com/en-us/library/system.string(v=vs.110).aspx

Answer 2

I feel so stupid for even asking this question now. I reviewed my own method, and the string needs to be tagged with the encoding type. and i KNEW this, thats why i append the <kbd/> to the string if it supports that encoding type. So, the <utf-16/> tag just needed to be appending to the start of the string. OMG, sorry for any time i may have wasted!

Answer 3

how would you get this to run with a Foreach($computer in $computername) loop? Where would the foureach be placed and would there be any special syntax?