Glen's Exchange and Office 365 Dev Blog

The Azure AD business-to-business (B2B) platform is the underlying tech that drives both guest access in Microsoft Teams,Office365 Groups and also other Azure resources. If your someone who collaborates across a number of different organization or potentially different Community or even school or university groups you might find your MSA or Office365 account starts to accumulate Guest access to different tenants. Depending on what type of access your accruing eg If it just Microsoft Teams access you will see your guest tenancies when logging on to Teams, another way is if you logon to the Azure Portal and hit switch directory you will get a list of Azure Directories your account has an association with.  However and easier way of doing this is using PowerShell along with the ADAL, Azure Resource Management and Graph API's. I put together the following script that uses first the Azure Resource Management API to make a request that gets all the Tenants associated wi...

This is a continuation somewhat of my previous post on using a generic oAuth script to access EWS but in this post I'm going to look at how you can authenticate as a Guest user to a tenant you have been granted Guest access to and then access the resources like a Unified Office365 Group or Teams( because Teams uses Groups) via the Graph API. To Access another tenant as a Guest (considering that Guest Access is enabled and you have accepted the invitation and logged in at least once with that user) you need to generate an Access Token against the Target tenants endpoints. To do this you can discover what a particular tenants Authentication and Token endpoints are by making a request like the following $RequestURL = " https://login.windows.net/{0}/.well-known/openid-configuration " - f $TargetDomain $Response = Invoke - WebRequest - Uri $RequestURL $JsonResponse = ConvertFrom - Json $Response . Content This will return a result like the following Out of thi...