Fix $SPOS variable for application to service principal relations

[iknowjason]

Thanks for AzureHound, a really interesting tool. I've been playing with and debugging the code and think I found an issue.

In this section of code listed below that is "processing the application to service principal relations", it looks like the $SPOS variable is supposed to return the data, but in fact it isn't being set:

https://github.com/BloodHoundAD/AzureHound/blob/master/AzureHound.ps1#L1359-L1370

$SPOS is being used later in the script to gather the application administrators and filter ServicePrincipalID, so the intent must be to use it. For example, here $SPOS is used: https://github.com/BloodHoundAD/AzureHound/blob/master/AzureHound.ps1#L1398

Here is a suggestion to make $SPOS populate the $ServicePrincipals. This sets $SPOS to what is added for the $Coll Array:

   $Coll = New-Object System.Collections.ArrayList
   Write-Info "Processing application to service principal relations"
   $SPOS = Get-AzADApplication | Get-AzADServicePrincipal | %{

    $ServicePrincipals = [PSCustomObject]@{
        AppId                   = $_.AppId
        AppName                 = $_.DisplayName
        ServicePrincipalId      = $_.Id
    }

    $null = $Coll.Add($ServicePrincipals)


    }

    $SPOS = $Coll

I tried to create a PR for this but it doesn't look like you allow random people to contribute. All good. Thanks!

[aress31]

I can indeed a confirm a bug when it comes to timestamp-azapplicationtosp.json, mine shows some null values which therefore affect the data completeness of BloodHound, see:

    {
        "AppId":  null,
        "AppName":  "REDACTED",
        "ServicePrincipalId":  "REDACTED",
        "ServicePrincipalType":  null
    },

[rvazarkar]

We appreciate the PR. Just letting you know that we're about to release an update to AzureHound that addresses this and several other things.