Category Archives: Powershell

Automation, EntraID, Powershell, Security

Silent provisioning of Fido key to use for headless requests against hidden API’s

4 Comments

So there’s this problem with lots of Microsoft API’s not allowing service principals to call them. I’ve written about this a few times in the past 🙂

These api’s want a user. And a user has to do MFA, right?

Not with this!

When I read Nathan McNulty’s LinkedIn post this morning I got a bit hyped and just HAD to get it working. He has a way to use a stored passkey to log in silently to all admin portals/hidden api’s etc.

The missing part I wanted to solve, is to actually generate that passkey for a given global admin in the tenant.

Took a bit of messing around with how to generate the keys using a virtual authenticator, but it works! Here it is:

https://github.com/jflieben/assortedFunctionsV2/blob/main/New-FidoKey.ps1

So basically:

  1. register app with client id/secret and UserAuthenticationMethod.ReadWrite.All
  2. run New-FidoKey
  3. use the file it outputs with Nathan’s passkey login function

I should also give an honorary mention to Fabian Bader for the work he did to get us here!

disclaimer: don’t store this stuff where anyone can find it!

disclaimer2: you’ll have to set your fido policy to allow not force attestion or key restrictions

M365AutoLink, Microsoft Teams, OneDrive for Business, Powershell, Sharepoint Online

M365AutoLink

1 Comment

We often still have legacy apps around. First advice is always; get rid of them 🙂

But sometimes, that’s not the option the customer wants to pay for, so alternatives need to be researched. Commercial tools like IAMCloud Drive Mapper work really well in exposing Teams/Sharepoint as driveletters on endpoints (for a price).

But free solutions are limited to automapping using GPO’s or letting users sync each team they need access to manually. This often causes issues on multiple fronts that I’m sure you’ve already experienced if you’re reading this.

So here’s an alternative to try! M365AutoLink is a PowerShell script you can execute on the user’s device. It’ll try to use SSO and then:

  1. check all sites the user has access to (including Teams)
  2. filter sites you do and don’t want
  3. create a folder in their onedrive if it doesn’t exist yet (you can decide how to name it)
  4. add all these sites as shortcuts in this folder
  5. remove any shortcuts the user no longer has access to

And since Onedrive syncs these links, any legacy apps on the user’s device can now also directly access Teams/Sharepoint, without syncing down the entire library or using drive mappings!

Documentation and download

https://github.com/jflieben/M365AutoLink

Powershell, Sharepoint Online

Microsoft Office Server Directory DirectoryObject NotFound Exception

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Can’t delete a sharepoint site that used to have a group attached to it, but the group has long since been deleted?

Apparently, the sharepoint admin center is unable to handle this scenario, and just throws a “could not be deleted” error. Using fiddler the only extra info I could get was an underlying 500 Internal Server Error Microsoft.Office.Server.Directory.DirectoryObjectNotFoundException was thrown

Obviously that directory object not found means the office 365 group. Fora seem to point to MS support for manual fixes, but since Microsoft Support has rarely been a pleasant experience for me I went over the PS module for SPO and found a MUCH faster fix, hope it also works for you!

  1. start PowerShell 5 (don’t use a newer version until the module supports it)
  2. install-module Microsoft.Online.SharePoint.PowerShell -force -scope currentuser (unless you already have the module installed)
  3. import-module Microsoft.Online.SharePoint.PowerShell
  4. Set-SPOSite -Identity https://xxx.sharepoint.com/sites/xxx -ClearGroupId
  5. Remove-SPOSite -Identity https://xxx.sharepoint.com/sites/xxx -noWait
Automation, EntraID, Identity, M365Permissions, Powershell

Categorizing Service Principals in Entra

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For M365Permissions I wanted to categorize service principals in an actually useful way.

This is what I came up with so far

    function get-servicePrincipalType{
        Param(
            [Parameter(Mandatory=$true)][object]$spn
        )

        #managed identities are simple :)
        if($spn.servicePrincipalType -eq "ManagedIdentity"){
            return "ManagedIdentity"
        }        

        #other SPN's can be hosted by us, by Microsoft or by a third party 
        #Although 9188040d-6c67-4c5b-b112-36a304b66dad is also officially Msft, it contains consumer apps not built or vetted by Microsoft thus we treat it as third party
        if($spn.appOwnerOrganizationId -in ("f8cdef31-a31e-4b4a-93e4-5f571e91255a","72f988bf-86f1-41af-91ab-2d7cd011db47","7579c9b7-9fa5-4860-b7ac-742d42053c54")){
            return "MicrosoftApplication"
        }elseif($spn.appOwnerOrganizationId -eq <YOURTENANTID>){
            #this is either a homebrew app or an AI agentic app
            if($spn.tags -and ($spn.tags -contains "AgenticApp" -or $spn.tags -contains "AIAgentBuilder")){
                return "AiAgent"
            }else{
                return "InHouseApplication"
            }
        }else{
            return "ThirdPartyApplication"
        }              
    }

Automation, EntraID, Powershell, Security

Function to Spot ALL All-User and All-Guest Groups in Entra ID

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There are probably many scenario’s where you’d like to identify which Entra groups contain ‘all users’, ‘all guests’ or a combination (all members+all guests).

In my case, I want to use this in M365Permissions, but also needed it for a Maester test to be more precise. It had to be language and implementation agnostic.

M365Permissions uses this mainly for reports that look at oversharing (e.g. when securing a tenant or implementing copilot). But this could also be useful for red/blue teams or any other tenant analysis tooling.

In M365Permissions, I initially looked at the dynamic rule itself, but this is unreliable. Dynamic rules can contain many additional components and can be ordered or written in many ways or the group may have been created without a dynamic rule through e.g. automation.

So I decided to use another approach!

Just get all tenant users from Graph (counts per type).

Then for a given group, look if it matches one of those counts and return a type. Of course, casting members to users to avoid counting devices and looking up membership recursively 🙂

Function: https://github.com/jflieben/assortedFunctionsV2/blob/main/Get-EntraDynamicGroupType.ps1