February 13, 2019

Expiring Group Membership

As a systems administrator working with Active Directory your probably proficient in granting access to network resources. How good are you at removing permissions once the access is no longer needed? Probably not as good. Enter Expiring Group Membership in Active Directory. You can specify how long an object belongs in a group. Active Directory handles the removal for you.

To use Expiring Group Memberships, make sure that the feature is enabled in your forest. This is a feature added in Server 2016 and is not on by default.

## If Enabled EnabledScopes 
## won't be empty

$Forest = Get-ADForest
Get-ADOptionalFeature -Identity 'Privileged Access Management Feature'

## Enable Privileged Access

$enableADOptionalFeatureSplat = @{
    Scope = 'ForestOrConfigurationSet'
    Target = $Forest
    Identity = 'Privileged Access Management Feature'
Enable-ADOptionalFeature @enableADOptionalFeatureSplat

Existing groups should work but if you don't have one, create a group now.

$newADGroupSplat = @{
    GroupCategory = 'Security'
    DisplayName = "Temporary Membership"
    GroupScope = 'Global'
    Name = 'TempGroup'
New-ADGroup @newADGroupSplat

Now add the membership using the MemberTimeToLive parameter.

$addADGroupMemberSplat = @{
    Members = 'ngetchell'
    MemberTimeToLive = ( New-Timespan -Days 365)
    Identity = 'TempGroup'
Add-ADGroupMember @addADGroupMemberSplat

Expiring Membership Report

Now to generate a report to show off a members and their membership timespan. You could even pipe to Excel if you'd prefer.

Get-ADGroup -Identity TempGroup -ShowMemberTimeToLive -Properties members | 
    Select-Object -ExpandProperty members | 
    ForEach-Object {
    if ( $_ -match '<TTL=' ) {
        $ttlstring, $DN = $_ -split '>'

        [int]$ttl = $ttlstring -replace '<TTL='
        $Timespan = New-Timespan -Seconds $ttl

            MemberDN   = $DN -replace "^,", ""
            TTL        = $Timespan
            ExpiryDate = $((Get-Date).Add($Timespan))

    else {

            MemberDN   = $_
            TTL        = 0
            ExpiryDate = 0

} | Export-Excel -Path ~\Desktop\ExpiringGroupMembers.xlsx


Previewing Server 2016 TP4: Temporary Group Memberships
How the Active Directory Expiring Links Feature Really Works
One of the new features in Windows Server 2016 will be the Active Directory Expiring Links feature, which enables time-bound group membership, expressed by a time-to-live (TTL) value. Here is how it works: Enabling the Expiring Links Feature The Expiring Links feature had been a standalone feature i…