Immutable ID, ms-ds-consistencyGUID, and object GUID conversions

It seems like I'm constantly need to convert immutable IDs and GUIDs as part of my M365 migrations. To simplify this I finally got around to writing some functions that simplify the work instead of looking them up all the time.

I created the following:

• Convert-ImmutableIDToGUID
• Convert-ImmutableIDtoHexString
• Convert-ImmutableIDtoByteArray
• Convert-ByteArrayToGUID
• Convert-GUIDToImmutableID
• Convert-HexStringToGUID
• Convert-HexStringToImmutableID
• Convert-ByteArrayToImmutableID

To make these available at a powershell prompt, you can load them as part of your powershell profile or dot source a script that contains.

Example of dot sourcing:

. c:\scripts\convertfunctions.ps1

Code for the functions:

# Example immutable ID to play with
# $ImmutableID = "GJo33fsMIUKvmIIyTOSjzg=="

function Convert-ImmutableIDToGUID {
    param ($ImmutableID)
    $guid=[Guid]([Convert]::FromBase64String($ImmutableID))
    return $guid
}


function Convert-ImmutableIDtoHexString {
    param ($ImmutableID)
    $hexstring=([Convert]::FromBase64String($ImmutableID) | ForEach-Object ToString X2) -join ' '
    return $hexstring
}


function Convert-ImmutableIDtoByteArray {
    param ($ImmutableID)
    $bytearray=[Convert]::FromBase64String($ImmutableID)
    return $bytearray
}


#When you retrieve ms-ds-consistencyGUID from AD it is a byte array
#to avoid this conversion use [guid]$user.'ms-ds-consistencyGUID'
function Convert-ByteArrayToGUID {
    param ($bytearray)
    $guid=[Guid]([Convert]::FromBase64String([system.convert]::ToBase64String($bytearray)))
    return $guid
}

#works with GUID object or string in GUID format
function Convert-GUIDToImmutableID {
    param ($guid)
    $immutableID = [system.convert]::ToBase64String(([GUID]$guid).ToByteArray())
    return $immutableID
}


function Convert-HexStringToGUID {
    param ($hexstring)
    $guid = [GUID]([byte[]] (-split (($hexstring -replace " ", "") -replace '..', '0x$& ')))
    return $guid
}


function Convert-HexStringToImmutableID {
    param ($hexstring)
    $ImmutableID = [system.convert]::ToBase64String([byte[]] (-split (($hexstring -replace " ", "") -replace '..', '0x$& ')))
    return $ImmutableID
}


function Convert-ByteArrayToImmutableID {
    param ($bytearray)
    $ImmutableID = [system.convert]::ToBase64String($bytearray)
    return $ImmutableID
}

<# Use Example

$msdsconsistencyGUID = (Get-ADUser Byron -properties *).ms-ds-consistencyGUID
$ImmutableID = Convert-ByteArrayToImmutableID -bytearray $msdsconsistencyGUID
Set-AzureADUser byron@domain.com -ImmutableID $ImmutableID

#>