Category Archives: Automation

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

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

Categorizing Service Principals in Entra

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"
        }              
    }      

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

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

M365Permissions v1.2.3

Performance improvements and Onenote Notebooks.

Today’s release has a ‘special guest’; Morten (blog)! He completely rewrote the entra user and group retrieval code, greatly improving both performance and total capacity!

Other changes of note:

  1. Add support for Onenote Notebook sharing permissions
  2. Treat anonymous sharing links as ‘deleted’ if the sharing level at the site forbids anonymous sharing

Full changelog here

Download / Use:

M365Permissions module page | Github | PSGallery

M365Permissions v1.2.2

Are you also curious about all those PowerApps and Flows in your environment? Orphaned ones maybe? Or when someone leaves the company?

1.2.2 adds scanning of PowerApps and Flows! Only when using SPN auth. (setup instructions)

In addition to that, I’ve also added provisional support for scans of tenants in USGOV, USDOD and China. Since I don’t have a test tenant there, I’ll have to rely on you to test how it performs there.

Full changelog here

Download / Use:

M365Permissions module page | Github | PSGallery