Get-BitLockerStatus.ps1

<#
.SYNOPSIS
    Gets the current status of BitLocker.
.DESCRIPTION
    Tests the current status of BitLocker Drive Encryption on an Encryptable Volume.  Only returns true if the volume is fully encrypted and the protection status is on.
.INPUTS
	System.String.
.OUTPUTS
	System.Management.Automation.PSObject
.PARAMETER ComputerName
    System to evaluate BitLocker against.
.PARAMETER DriveLetter
    Drive letter to evaluate BitLocker against.  if NullOrEmpty the default SystemDrive will be used.
.EXAMPLE
    Get-BitLockerStatus
.EXAMPLE
    Get-BitLockerStatus -ComputerName "mycomputer.mydomain.com" -DriveLetter C:
.NOTES
    If no drive letter is specified, the default system drive will be used.
    The drive letter must be followed with a double colon.  IE: "C:".
.LINK
    http://msdn.microsoft.com/en-us/library/windows/desktop/aa376483%28v%20=%20vs.85%29.aspx
.LINK
    http://dotps1.github.io
#>
Function Get-BitLockerStatus  {    
    [CmdletBinding()]
    [OutputType(
        [PSObject]
    )]
    
    Param (
        [Parameter(
            ValueFromPipeline = $true
        )]
        [ValidateScript({ 
            if (Test-Connection -ComputerName $_ -Quiet -Count 2){ 
                $true 
            }
        })]
        [String[]]
        $ComputerName = $env:COMPUTERNAME,

        [Parameter(
            HelpMessage = "Drive letter format must be letter followed by colon, 'C:'"
        )]
        [ValidatePattern(
            '[a-zA-Z]:'
        )]
        [String]
        $DriveLetter
    )

    Process {
        foreach ($item in $ComputerName) {
            if (-not ($DriveLetter)) {
                try {
                    $drive = Get-WmiObject Win32_OperatingSystem -Namespace 'root\CIMV2' -ComputerName $item -Property SystemDrive -ErrorAction Stop
                    $volume = Get-WmiObject -Class Win32_EncryptableVolume -Namespace 'root\CIMV2\Security\MicrosoftVolumeEncryption' -Filter "DriveLetter = '$($drive.SystemDrive)'" -ComputerName $item -ErrorAction Stop
                }
                catch {
                    throw $_
                }
            } else {
		        try {
			        $volume = Get-WmiObject -Class Win32_EncryptableVolume -Namespace "root\CIMV2\Security\MicrosoftVolumeEncryption" -Filter "DriveLetter = '$DriveLetter'" -ComputerName $item -ErrorAction Stop
			        if ($volume -eq $null) {
				        throw "Failed to enumarate the Win32_EncryptableVolume Namespace for $DriveLetter.  Please make sure the drive letter is correct and that the volume is accessable."
			        }
		        } catch {
			        throw $_
		        }
            }

            switch ($volume.GetConversionStatus().ConversionStatus) {
                0 { $state = 'FullyDecrypted' }
                1 { $state = 'FullyEncrypted' }
                2 { $state = 'EncryptionInProgress' }
                3 { $state = 'DecryptionInProgress' }
                4 { $state = 'EncryptionPaused' }
                5 { $state = 'DecryptionPaused' }
                default { $state = 'Unknwon' }
            }

            if ($volume.GetProtectionStatus().ProtectionStatus -eq 0) {
                $protection = "ProtectionOff"
            } else {
                $protection = "ProtectionOn"
            }

            $bdeStatus = [HashTable] @{
                'PSComputerName' = $item
		        'Protection' = $protection
		        'State' = $state
		        'Percentage' = $volume.GetConversionStatus().EncryptionPercentage
            }
    
	        Write-Output -InputObject $bdeStatus
    }
}