Convert IADsLargeInteger to Int64 in PowerShell

Some Active Directory attributes return an 8 byte integer in the form of an IADsLargeInteger interface. An example is the pwdLastSet attribute from a user object.

Because the IADsLargeInteger object doesn’t provide type information PowerShell cannot read the HighPart and LowPart properties.

So I wrote the function below to get the Int64 value of an IADsLargeInteger:

function AdsLargeIntegerToIn64($adsLargeInteger)
	[Int32]$highPart = $adsLargeInteger.GetType().InvokeMember("HighPart", [System.Reflection.BindingFlags]::GetProperty, $null, $adsLargeInteger, $null)
	[Int32]$lowPart  = $adsLargeInteger.GetType().InvokeMember("LowPart",  [System.Reflection.BindingFlags]::GetProperty, $null, $adsLargeInteger, $null)
	return  [Int64]("0x{0:x8}{1:x8}" -f $highPart, $lowpart)